JP2000154337A - Lightweight structure and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide both a lightweight structure having a high strength, excellent in water, weather and fouling resistances and heat insulating properties and more resistant to heat than a conventional product and a method for producing the lightweight structure. SOLUTION: This lightweight structure has an inner layer and an outer layer and the inner layer is a foam. The outer layer is formed of a composition containing a synthetic resin emulsion so as to provide <=20 wt.% amount of an organic material used based on amorphous silica, a cement, quartz sand and an inorganic component. The foam is preferably a resin foam preferably provided with a reinforcing member.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a building block,
The present invention relates to a lightweight structure used in place of a stone, an exterior material, and the like, and a method for manufacturing the same.

[0002]

2. Description of the Related Art Structures such as flower beds, fences, gate pillars, and block-shaped structures used in buildings are, for example, those cut out from natural stone materials such as marble, granite, and valley stone, concrete blocks, bricks, and the like. Tiles and the like are well known. Natural stones are expensive and heavy, and concrete blocks and bricks are inexpensive, but they are still heavy and cannot be easily transported. Even the strength of itself can be a problem.

As a block-shaped structure having a certain shape to solve such a weight problem, a water-based adhesive having low solubility in styrene resin is used on the surface of a block made of styrene foam as an inner layer. Lightweight structures are commercially available in which granules of natural stone such as gravel are bonded to form an outer layer.

As exterior materials for structures such as buildings and bridges, exterior walls such as ricin and stucco are painted, siding materials are constructed, and marble and granite panels are constructed.

[0005]

However, a structure in which inorganic particles such as natural stones are simply bonded to a resin foam using a water-based adhesive is certainly good in appearance and light in weight. It has the following problems. (1) Since only an aqueous adhesive is used as a binder, the adhesive strength is reduced when the adhesive comes into contact with water, and inorganic particles are peeled off from the outer layer. Therefore, even when used outdoors or indoors, it cannot be used for applications that come into contact with water. (2) The general water-based adhesive has a low resin hardness, and as a result, the strength of the structure itself, particularly the surface hardness, is insufficient because the strength of the outer layer is not sufficient. (3) When the resin constituting the inner layer is deformed due to shrinkage due to drying of the binder component or a reason considered to be due to a monomer or solvent remaining slightly in the adhesive, and the structure is deformed with time. There is. (4) Vulnerable to heat, especially easily damaged by flame.

[0006] On the other hand, with respect to conventional building materials and known exterior materials for buildings, the exterior wall coating materials do not have sufficient weather resistance, stain resistance, heat insulation properties, etc., and need to be regularly repainted. Poor in weather resistance and lack of luxury. Further, natural stones such as marble and granite are heavy, expensive, and are susceptible to acid water.

An object of the present invention is to provide a lightweight structure which has high strength, is excellent in designability, water resistance, heat insulation, stain resistance, acid resistance, etc., and is more resistant to heat than conventional products, and a method for producing the same. It is in.

[0008]

SUMMARY OF THE INVENTION The present invention comprises an inner layer and an outer layer, wherein the inner layer is a foam, and the outer layer is amorphous silica or a compound containing the same, cement, silica sand, and the use of organic substances for inorganic components. The present invention relates to a lightweight structure characterized by being formed from a composition containing a synthetic resin emulsion so that the amount is 20% by weight or less.

By using a foam as the inner layer, lightness can be ensured. Since amorphous silica and cement are used as essential components as the outer layer, these components react to form a coating layer, and the strength and water resistance are improved. A layer having In addition, a synthetic resin emulsion is used. However, since the amount of the organic material used as the resin is 20% by weight or less, the heat resistance is superior to that of a conventional lightweight structure, and there is no influence on the inner layer foam. It is thought that silica sand has the effect of increasing the strength of the coating film and reducing the distortion due to curing shrinkage.

A major feature of the present invention is that the amount of the organic material used as the resin is 20% by weight or less. When a resin emulsion is used as a binder and inorganic particles are bonded as in a conventional lightweight structure, if the amount of the resin used is less than 20% by weight, sufficient adhesive strength cannot be obtained, and the particles may be separated. Occur.

[0011] The lightweight structure of the present invention has a great feature particularly in the outer layer. That is, by the action presumed to be a synergistic effect of the reactivity of the amorphous silica and the cement itself, the silica sand, the coloring aggregate to be added as necessary are combined by a chemical reaction, and only the synthetic resin emulsion is used as a binder. Rather, the particles are firmly adhered to the inner layer, and the outer layer itself forms a layer having excellent strength, water resistance, etc., to obtain a lightweight structure having an outer layer which is far superior in weather resistance and base substrate protection ability. be able to.

Further, the lightweight structure of the present invention does not melt or ignite even when it is in direct contact with a flame because the surface is inorganic, and has excellent performance in disaster prevention. In addition, the surface of the inorganic material has a large amount of hydroxyl groups (OH), is extremely hydrophilic, and the pollution caused by the attachment of oily pollutants contained in automobile exhaust gas and the like causes rainwater between the pollutants and the outer layer surface. Is very effectively prevented due to permeation and washing out of contaminants.

In a preferred embodiment, a fibrous material is added as a component constituting the outer layer of the lightweight structure of the present invention. Fibrous materials are more flexible than concrete, so paints containing them are shock-absorbing and have the ability to follow the deformation of the substrate, such as cracking or falling off due to the impact of flying stones. Therefore, even if deformation such as expansion due to direct sunlight or the like occurs, the outer layer does not crack and prevents water from entering the inner layer.

The foam used as the inner layer in the lightweight structure of the present invention is preferably a resin foam.

An inner layer having various densities, strengths, and shapes can be obtained, a low-cost material can be used, and a lightweight structure excellent in heat insulation can be obtained.

It is preferable that the foam has a reinforcing member, which contributes to the improvement of the strength of the inner layer.

The reinforcing member may be provided in a state of being buried inside the foam, may be laminated on the outer surface, or may be provided on both the inner and outer surfaces. Is also good. When buried inside, it exerts the effect of improving the strength of the structure when bending stress is applied, etc.When it is the outer surface and it is laminated as a lower layer of the outer layer, it is sharp from the outside It exerts the effect of improving the surface strength so that the structure is not damaged when receiving an impact force such as when an object collides.

In the present invention, the outer layer is formed so as to cover the entire surface of the inner layer, and one of the outer layers has an independent block shape.
It may have a shape such as a natural stone, and at least one
It may be formed in a panel shape with its surface covered.
The panel may be as large as the entire wall, 30 cm
It may be formed in a rectangular shape such as a square, a 1 m square or the like, or a desired small panel shape such as an ellipse or a diamond.

The present invention provides a method for manufacturing a lightweight structure comprising an inner layer and an outer layer, wherein the inner layer is a foam, wherein the foam has a predetermined shape as an inner layer, and the surface of the foam has an amorphous silica-containing compound and cement. And a method for producing a lightweight structure comprising a step of coating a composition containing a synthetic resin emulsion to form an outer layer such that an amount of an organic substance based on silica sand and an inorganic component is 20% by weight or less. Thus, the lightweight structure of the present invention can be easily manufactured by such a method.

The lightweight structure of the present invention can be fixed and locked on the surface of a base material such as concrete or steel, or can be used by being appropriately stacked like a concrete block or natural stone. In the case of construction, the inner layer material may be fixed and locked to the base material, and then the outer layer material may be constructed to form a lightweight structural material. An object may be manufactured, and this panel-shaped lightweight structure may be mounted on a substrate.

In a preferred embodiment, the light-weight structure of the present invention is provided with a concavo-convex pattern on the exterior side surface so as to impart a design property.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION As the amorphous silica used as an outer layer forming component in the present invention, a reactive curable so-called reactive silica can be used, and it is produced by the method described in JP-A-4-182338. It is particularly preferred to use activated shirasu.

As the cement, cements such as air-hardened cement and hydraulic-hardened cement (Kyoritsu Shuppan, Chemical Dictionary) can be used. In particular, generally used cements such as Portland cement and alumina cement can be used without limitation, but white cement is preferred because the color tone can be freely adjusted.

The silica sand containing 90% or more of SiO ₂ and generally called silica sand can be used without any limitation, and glass particles and the like can also be used.

The mixing ratio of these materials is 100 parts by weight of amorphous silica, 10 to 1000 parts by weight of cement, preferably 100 to 1000 parts by weight, and silica sand is 2 parts by weight.
0 to 200 parts by weight, more preferably 50 to 200 parts by weight, the organic binder is 100 parts by weight or less as a resin,
It is more preferably in the range of 50 parts by weight or less. As described above, the amount of the organic binder is preferably 20% by weight or less as a solid content, more preferably 15 to 3% by weight, based on the total inorganic content. If it exceeds 20% by weight, the weather resistance is reduced and the adhesive strength is also reduced.

As the outer layer material of the present invention, it is also preferable to add an aggregate such as a colored aggregate in addition to the above-mentioned components, and a structure having a natural stone-like appearance such as granite can be obtained.

As such an aggregate, natural stone powder, colored silica sand, porcelain sand, sand, blast furnace slag and the like can be used, and the roughness is 1
0 to 150 mesh, preferably 20 to 80 mesh, and if it is within this range of roughness,
You may mix fine things. Silica sand is a metal oxide,
For example, by mixing CuO, MnO _2, etc. and heating to several hundred degrees, it is possible to easily color, and therefore, it is also possible to use both silica sand and colored aggregate. Such silica sand and aggregate are 10
If it is less than the mesh, it will be too coarse, and the unevenness of the painted surface will be remarkable, resulting in poor appearance. On the other hand, if it is 150 mesh or more, the particles become too fine to absorb the strain due to curing shrinkage, and as a result, cracks are easily formed.

The amount of the above-mentioned aggregate is 30 to 300 parts by weight based on 100 parts by weight of the amorphous silica. 30
If the amount is less than 30 parts by weight, no improvement in appearance is observed.
If the amount exceeds 0 parts by weight, the properties of the outer layer deteriorate.

As the fibrous material, fibers having a reinforcing effect (including whiskers) can be used. For example, fibers obtained from organic polymers such as fibers of polyester and nylon, aramid fibers, cotton yarns, and potassium titanate whiskers (products) Fibers of inorganic materials such as Tismo Otsuka Chemical Co., Ltd., glass fibers, wollastonite, and metal fibers, for example, brass, iron, and aluminum short fibers (manufactured by Tokyo Steel) manufactured by chatter vibration cutting can be used. In addition to these, carbon fibers can also be used, and those obtained by treating fibers such as acrylonitrile fibers and pitch-based carbon fibers can be used. The use of pitch-based carbon fibers is preferred from the viewpoint of cost. As these fibers are known in the case of composite materials, those having an aspect ratio of 5 or more and a fiber length of 0.3 mm or more can be used, and preferably have a fiber diameter of 10 to 500 μm and a length of 2 to 100 mm. It is.

These fibrous materials are preferably added in a range of 100 parts by weight or less based on 100 parts by weight of the amorphous silica. If it is added in excess of 100 parts by weight, the appearance of the outer layer deteriorates.

The synthetic resin material to be added in addition to the above components is added in a small amount as long as it does not affect the weather resistance. Materials that can be used are aqueous solutions or aqueous dispersions (generally called resin emulsions), for example, latexes such as acrylic / styrene copolymer emulsions, acrylic resin emulsions, polyurethane emulsions, and natural rubber latex. Particularly, a reactive epoxy emulsion, an acrylic resin emulsion, an acrylic / silicone emulsion and the like are preferable. Mixing two or more of these can be used without any problem.

In the present invention, in particular, the minimum film forming temperature (M
FT) is 10 ° C. or more, more preferably 25 ° C. or more, and it is preferable to use a self-crosslinking styrene-acrylic emulsion having a glass transition temperature of the resin of 5 ° C. or more, more preferably 10 ° C. or more, In particular, it is preferable to use an emulsion resin that reacts when heated to MFT or higher. Such a resin forms a hard and tough film, forms a film having excellent acid resistance, and is particularly excellent in properties such as water resistance, salt resistance, acid resistance and impact resistance of the outer layer by using this. A lightweight structure can be obtained.

After the coating composition is formed by spraying or the like, it is preferable to complete the outer layer by heating and drying, and it is possible to use hot air or an infrared heater. In the present invention, however, the heat of reaction between cement and water is used. In particular, the crosslinking reaction can proceed without providing a separate heating means.

As a method for forming the outer layer, it is preferable to make the outer layer forming component into a paint and apply it to the material constituting the inner layer. As a coating method, a method generally known as a coating method can be used. For example, spray coating, brush coating, dipping and the like. In particular, it is preferable to use a mortar gun or ricin gun, which is generally used for exterior wall coating, and it is also preferable to use a multi-head gun such as a two-head gun or a three-head gun to form an outer layer having a different color tone from each head. The method of discharging the material is preferable because an outer layer excellent in design can be formed.

When the above-mentioned outer layer constituting materials are mixed to form a paint, various dispersants and surfactants for improving dispersibility, and a water reducing agent for adjusting the viscosity and solid content of the paint. There is no problem in adding a thickener.
Examples of the thickener include inorganic materials such as silica-based materials such as Aerosil (manufactured by Nippon Aerosil Co., Ltd.), Hymetroses (manufactured by Shin-Etsu Chemical Co., Ltd.), hydroxyethyl cellulose (manufactured by Daicel Chemical Industries), and carboxymethyl cellulose (manufactured by Daiichi Kogyo Co., Ltd.). Organic products such as pharmaceutical cellulose) and methylcellulose.

It is preferable that an inorganic finishing material layer is further provided on the surface of the outer layer of the lightweight structure according to the present invention, if necessary. It is exemplified as a forming material. Such a finishing material layer has an effect of giving gloss, smoothness, and the like to the outer layer.

As the foam constituting the inner layer, a known foam can be used without particular limitation. Examples include inorganic material-based foams and organic material-based foams such as resin foams, and more specifically, a binder using inorganic hollow particles such as shirasu balloons and glass balloons as the inorganic material-based foams. And foams of water glass formed into a desired shape. Thermoplastic resins such as foamed polystyrene and foamed polyethylene as organic material-based foams, and polyurethane foams and phenol foams. Foams are exemplified.

Of the above foams, the use of expanded polystyrene (polystyrene foam) is particularly preferred in that a foam of any density and shape can be obtained at low cost.

When the irregularities are intentionally formed for improving the design, it is preferable to form the irregularities on the inner layer material as described above, and to uniformly form the outer layer thereon. As a method of providing unevenness on the inner layer, in the case of forming unevenness using a flat surface inner layer material as a starting material, a method of heating and melting the surface, a method of grinding with a grinding means such as a disk sander, Examples of the method include a method of compressing with a hot press, a method of charging an inner layer material forming material into a mold having a predetermined uneven shape, forming an inner layer material, and simultaneously imparting an uneven pattern. When polyurethane foam or polystyrene foam is used as the inner layer material, the latter method is preferable.

When the outer layer material is formed by spray coating, to eliminate irregularities caused by spray coating, immediately after coating, a mirror finish may be performed with an iron, a spatula, or the like in an undried state. It is also possible to use a disc sander or the like for polishing later, and by such an operation, it is possible to obtain a lighter structure having a higher-grade polished granite or marble appearance.

The lightweight structures of the present invention can be stacked using cement, mortar, etc., like concrete blocks.
Alternatively, it may be constructed by joining, or it may be constructed by using an adhesive, a sealant, a putty or the like.

The reinforcing material provided in the inner layer material has a plate-like, net-like, linear or other shape, and a high-strength material such as a metal, a resin, or a fiber is used without any particular limitation. It is possible. The reinforcing material may be embedded in the inner layer as described above, or may be fixed to the outer surface by bonding or the like. It is also a preferred embodiment that a part of the reinforcing material such as metal or resin is provided with a locking member for fixing the lightweight structure of the present invention to the base material. As such a reinforcing material, glass cloth and glass reinforced cement (GRC) are particularly preferable. The glass cloth is laminated on the foam surface using an emulsion adhesive or the like, and the glass reinforced cement is sprayed on the foam surface. Are laminated.

The lightweight structure of the present invention can be provided with a hollow structure like a concrete block, and can use a reinforcing member such as a reinforcing bar at the time of construction to increase the strength of the completed structure. Further, the lightweight structure of the present invention may have a fixed shape like a concrete block, and such a fixed block is used for constructing a structure such as a fence, a flower bed, a gate post, a retaining wall of a pool or a pond, an amusement park or a park. Can be used. In addition, it is possible to produce not only a fixed product but also an arbitrary shape such as a pond for breeding goldfish and carps to be installed in the garden.
In addition, it was constructed so as to cover the walls of existing buildings, to upgrade the appearance and at the same time to improve weather resistance and acid rain resistance,
At the same time, it is possible to improve the heat insulation.

[0044]

[Example 1]

Inner Layer The expanded polystyrene was molded into a block shape having a size of 30 cm × 20 cm × 10 cm to obtain an inner layer material.

Outer layer A coating composition for forming an outer layer having the following composition was prepared, applied to one surface of the inner layer material with a spray gun so that the thickness of the dried coating film became 2 mm, and dried to form a block-shaped lightweight material. Created a structure. The weight of the obtained structure was 450 g, which was about 7% of that when concrete was used. In addition, in the following examples, the compounding amount was shown by weight part. The obtained lightweight structure was evaluated as Example Sample 1.

[0046]

[Table 1]

[Table 2] The composition 1A and the composition 1B, which were previously uniformly mixed, were stirred and mixed with a hand mixer and used. The amorphous silica / cement weight ratio in this example is 100/2.
5, and the amount of resin used relative to inorganic materials such as aggregate and amorphous silica was 12% by weight.

Embodiment 2

[Table 3]

[Table 4] As the styrene acrylic emulsion, a self-crosslinking emulsion having an MFT of 30 ° C. and a glass transition temperature of a resin of 10 ° C. was used. Example 2 was prepared in the same manner as in Example 1 by mixing the above composition 2A and composition 2B which had been previously uniformly mixed.

Example 3 A glass cloth was bonded to the entire surface of the expanded polystyrene block used as the inner layer material in Example 1 using a commercially available vinyl acetate emulsion adhesive, dried, and then used in Example 2. The coating composition was coated in the same manner as in Example 2, and the sample of Example 3 was prepared.
It was created.

Example 4 In Example 2, the composition 2
Example sample 4 was prepared in the same manner as in Example 2 except that 10.0 parts by weight of a glass fiber chop strand having a fiber diameter of 15 μm and a length of 3 mm was further added to A.

Comparative Example 1 A structure to which inorganic particles were adhered using a commercially available adhesive was used as a sample of Comparative Example 1 and evaluated.

[Comparative Example 2] Except that in the coating composition described in Example 1, 1500 parts by weight of the styrene / acrylic copolymer resin emulsion (the amount of the resin component was 40% by weight based on the inorganic material) was used. Was used as Comparative Example Sample 2 in the same manner as in Example 1.

(Evaluation) (1) Evaluation of Water Resistance Each of Examples 1 to 4 and Comparative Examples 1 and 2 was immersed in tap water at a water temperature of about 24 ° C. at room temperature. 1
After leaving for 0 days, the samples of the example and the comparative example were taken out. The sample of the example had no abnormality at all. However, in the comparative example sample 1, the attached inorganic material was peeled off, and the organic foam inside the sample was removed. Partially exposed. Comparative Example Sample 2
Did not show any particular change.

(2) Evaluation of Acid Resistance Using the block-shaped lightweight structures of Examples 1 to 4, pools were prepared using cement mortar, and tap water having pH = 2 by dissolving sulfuric acid was stored. And left. 5
Observation was carried out after 000 hours except for the acidic water, but no abnormality was observed in the lightweight structure of the present invention.

The sample of Comparative Example 1 was not evaluated, and the same evaluation was performed of Sample 2 of Comparative Example. After 5000 hours, there was no significant change in appearance, but the inorganic material was partially peeled off. It was found that it sank to the bottom, indicating that the acid resistance was not sufficient.

(3) Evaluation of Impact Resistance For the samples of Examples 3 and 4, a commercially available umbrella weighing 500 g was used. The sample was dropped on the body from a height of 40 cm, and the sample surface was visually observed and evaluated. The results of the test are shown in Table 5. The display of the result is as follows. ：: No abnormality was observed at all.

Δ: A light dent that is practically acceptable is recognized.

×: Stone piercing penetrated the outer layer, and a hole was formed in the inner layer.

[0058]

[Table 5] From the above results, it is clear that the lightweight structure of the present invention is also excellent in strength.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) E04B 2/02 E04C 2/20 L E04C 2/20 1/04 L (72) Inventor Goro Wakisaka Neyagawa, Osaka No. 6-13, Motomachi, Ori-shi, Tokyo F term (reference) 2E162 CA01 CD02 CD03 FA11 FA12 FA14 FB07 4F100 AA01B AA20B AC02 AE01B AK01A AK01B AK12 AK25 AL05B BA02 CA24 DH00A DJ01A EH112 JH07 JH07 GBH JL06 JL09 JM01B YY00B 4J038 CA011 CG141 CJ031 DB001 DG001 HA446 HA456 HA496 MA10 NA04 NA05 NA11 NA15 PB05 PC04

Claims (5)

[Claims] 1. A synthetic resin emulsion comprising an inner layer and an outer layer, wherein the inner layer is a foam, and the outer layer is formed of amorphous silica, cement, silica sand, and a synthetic resin emulsion such that the amount of an organic substance with respect to an inorganic component is 20% by weight or less. A lightweight structure formed of a composition comprising: 2. The lightweight structure according to claim 1, wherein the foam is a resin foam. 3. The lightweight structure according to claim 1, wherein the foam has a reinforcing member. 4. A method for manufacturing a lightweight structure comprising an inner layer and an outer layer, wherein the inner layer is a foam, wherein the foam has a predetermined shape as an inner layer, and amorphous silica, cement, silica sand is provided on the surface of the foam. And a method for producing a lightweight structure comprising a step of applying a composition containing a synthetic resin emulsion to form an outer layer so that the amount of an organic substance to an inorganic component is 20% by weight or less. 5. The method according to claim 4, wherein the foam is a resin foam.