JPH059087A - Shirasu balloon molded body and manufacturing method thereof - Google Patents

Abstract

(57) [Summary] [Purpose] Development of a cured product of a composition containing water glass and a water glass curing agent in a shirasu balloon without shrinkage deformation or surface cracking. A plate-shaped molded product made of a cured product of a composition in which water glass and a water glass curing agent are mixed in a shirasu balloon, wherein a resin film is formed on both surfaces of the molded product. A composition obtained by mixing water glass and a water glass curing agent in a shirasu balloon is pressure-molded into a plate shape, pre-cured, and then a resin film is formed on both surfaces of the obtained plate-shaped molded body and dried and cured. A method for producing a characteristic Shirasu balloon molding.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lightweight molded product mainly composed of shirasu balloon and a manufacturing method thereof.

[0002]

2. Description of the Related Art Conventionally, a method for producing an inorganic lightweight building material by using shirasu balloon as an inorganic aggregate, 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-1-317148). The building material obtained by such a method is lightweight, and at the same time, is excellent in fire resistance, heat insulation and soundproofing. In such a lightweight molded body, as a problem difficult to solve, in particular,
If the thickness of the molded product is as thin as 25 mm or less, there is a problem that shrinking deformation, particularly warpage, or surface cracking occurs during drying. Due to such a problem, it is very difficult to produce a high-quality molded product with high productivity.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a lightweight molded body mainly composed of a shirasu balloon and a method for producing the same, which solves the above problems found in the prior art.

[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, there is provided a plate-shaped molded product made of a cured product of a composition in which water glass and a water glass curing agent are blended in a shirasu balloon, wherein A balloon molding is provided. Further, according to the present invention, a composition obtained by mixing water glass and a water glass curing agent into a shirasu balloon is pressure-molded into a plate shape, and after pre-curing, a resin film is formed on both surfaces of the obtained plate-shaped molded body. Provided is a method for producing a Shirasu balloon molded body, which comprises forming and drying and curing.

In the present invention, a mixture of shirasu balloon, water glass and powdery water glass curing agent is used as a raw material for molding. As the shirasu balloon, those having an average particle diameter of 20 to 600 μm are used, and a preferable shirasu balloon has a content of a component having a particle diameter of 63 μm or less (hereinafter, also referred to as A component) of 15 to 55% by weight, preferably A mixture of a coarse shirasu balloon and a fine shirasu balloon having a content of 20 to 50% by weight and a component having a particle size of 63 μm (hereinafter, also referred to as B component) of 45 to 85% by weight, preferably 50 to 80% by weight. is there. 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 No. 3 standard product. Etc. are commercially available. As the powdery water glass curing agent, conventionally known ones, for example, in addition to silicofluoride such as sodium silicofluoride, metal oxides such as zinc oxide and magnesium oxide; calcium carbonate, barium sulfate, calcium sulfate, condensed phosphoric acid. Examples thereof include metal salts such as aluminum. Carbon dioxide is generally known as a curing agent for curing water glass, but the use of carbon dioxide must be avoided in the method of the present invention. This is because when the water glass is attempted to be cured with carbon dioxide, the surface of the molded product is sintered at the pre-curing stage, and the sinter substance prevents the resin film forming material from being applied to the surface of the molded product. Because it will be. The amount of water glass used is 30 to 1 in terms of solid content (alkali metal silicate) based on 100 parts by weight of Shirasu balloon.
50 parts by weight, preferably 40 to 130 parts by weight. 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.

In the present invention, a polymer binder may be used in combination in order to increase the mechanical strength of the molded product. 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, methyl cellulose, polyvinyl pyrrolidone, and the like. As the polymer latex, styrene / butadiene latex,
Acrylic latex makoto, vinylidene chloride latex,
Vinyl chloride latex, vinyl acetate 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. If the proportion of polymer binder used increases, the non-combustibility, heat resistance, mold resistance, hardness, etc. of building materials will be impaired. From the viewpoint of obtaining non-combustible building materials, the proportion of polymer binder used is 5 parts by weight. The following is recommended. Further, in the present invention, a reinforcing fiber may be used in combination, if necessary, in order to enhance the mechanical strength. Examples of the reinforcing fiber include vinylon fiber, acrylic fiber, aramid fiber, polyester fiber, polyamide fiber, cellulose fiber, cotton, carbon fiber and other synthetic fibers and natural fibers, as well as metal fiber, alumina fiber, glass fiber, gypsum whiskers and the like. Various metals 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 m.
m. The ratio of reinforcing fibers used is Shirasu Balloon 10
It is usually 0.1 to 10 parts by weight, preferably 0.5 to 5 parts by weight, relative to 0 parts by weight. Furthermore, in order to increase the viscosity of the raw material mixture and prevent shrinkage during molding and curing, unexpanded shirasu powder or inorganic powder such as mica or kaolin can be used in combination. The average particle size of such an inorganic powder is usually 70 μm or less, preferably 0.1 to 30 μm. The proportion of such inorganic powder used is 40 parts by weight or less, preferably 30 parts by weight, based on 100 parts by weight of Shirasu balloon.
It is less than or equal to parts by weight. In the present invention, the raw material for molding is
Its water content is 10 to 50% by weight, preferably 20 to
It is kept at 40% by weight and used as a powdery material having fluidity. Such a powdery or granular mixture can be put into a mold and easily pressure-molded.

In the case of obtaining a molded product according to the present invention, it is preferable to fill the molding raw material in a mold, take out the molded product from the mold after pressure molding, and cure the pressure molded product at room temperature or under heating. . In this pressure molding, the molded body can be cured in the mold, but since the pressure molded body is a solid material and is easy to handle, the molded body is taken out of the mold and It is preferable to hold at room temperature or under heating for pre-curing. When the molded body is cured under heating, the heating temperature is 30 ° C or higher, preferably 80 ° C.
The following temperatures are adopted, and the curing time is usually 1 to 3
It's time. The heat-cured product of the molded product can be used as a light-weight plate as it is, but in order to further promote the curing reaction and improve the mechanical strength, at room temperature or at a temperature near room temperature, 2 to
It is preferable to use it after holding it for about 10 days. Pressing pressure during molding exceeds 5 kg / cm ² and 20 kg /
less than cm ² G, preferably 5.5-19 kg / c
It is preferable to specify in the range of m ² G. A molded product molded at a pressure molding pressure of 5 kg / cm ² G or less does not have a tight adhesion between particles, is likely to be broken at the ends, lacks dimensional stability, and is likely to generate cracks. There are disadvantages such as. In addition, the bending strength is low, and there is a possibility that the strength is still insufficient as a building material. On the other hand, in a molded product molded under a pressure molding pressure of 20 kg / cm ² G or more, the shirasu balloon itself is totally destroyed, and the resulting molded product has a variation in thickness. The advantages of low thermal conductivity and non-water absorption of Shirasu balloon may be impaired.

The plate-like pre-cured molded product obtained as described above contains water in an amount of about 10 to 30% by weight, and is still curable. In the present invention,
A resin film is formed on both sides of this still curable molded product, and in this state, it is left at room temperature or in a heating atmosphere of 30 to 80 ° C. for further dry curing (curing) to complete the curing. The product (water content 5% by weight or less).

Examples of the resin film forming material include a thermoplastic resin, a thermosetting resin, and a polymerizable composition which is cured by light or an electron beam. More specifically, thermoplastic resins such as polyester, nylon, polyolefin and polystyrene; thermosetting resins such as epoxy resin, urethane resin, phenol resin, unsaturated polyester resin and melamine resin, acrylic acid ester and methacrylic acid ester. Examples thereof include a photopolymerizable composition and the like. From the viewpoint of work efficiency, it is preferable to use a material having a high curing rate (or polymerization rate) as these resin film forming materials. The preferred resin film forming material used in the present invention is a photopolymerizable composition containing acrylic acid ester or methacrylic acid ester as a polymerizable component. As a method for forming a resin film on a molded body, a conventionally known method can be adopted. For example, a method of applying a resin film forming material in a liquid or solution form, heating or irradiating with light, a method of laminating in a film form, adhering with an adhesive or thermocompression bonding, applying a heat-melted resin liquid, and cooling. There is a method of doing this, a method of applying powder paint, and the like. An appropriate method is adopted depending on the characteristics of the resin film forming material used. The thickness of the resin coating formed on the surface of the molded body is usually 1 to 300.
It is 0 μm, preferably 5 to 2000 μm.

[0010]

EFFECTS OF THE INVENTION Even if the molded product of the present invention is as thin as 25 mm or less, it does not cause shrinkage deformation and cracks as seen in conventional thin molded products. That is, in the present invention, a resin film is formed on both surfaces of a molded product which contains water and has not been completely cured, and the molded product is dried and cured in this state. Since the resin film is formed on both surfaces of the molded product, the molded product starts from the peripheral end surface without the resin film and the molded product is dried at a slow speed. By such dry curing, a molded product free from shrinkage deformation and cracks can be obtained. Further, when a resin film is formed on the side surface of the dried molded body in the same manner as on both sides, it is possible to prevent precipitation of white sinter from the side surface for a long period of time. When the resin film is formed on the side surface of the molded body, it is not always necessary to dry the molded body completely, and it may be performed after the water content in the molded body is 5% by weight or less. The molded product of the present invention is advantageously applied as a wall material, a floor material, a ceiling material and the like.

[0011]

EXAMPLES The present invention will now be described in more detail with reference to Examples. All parts and% shown below are based on weight.

Example 1 100 parts of Shirasu balloon, water glass (JIS No. 3 product)
104 parts of powdery water glass curing agent (condensed aluminum phosphate) and 14 parts are uniformly mixed to obtain a powdery material having a water content of 27%, and then the mixture is molded into a mold (length: 400 m).
m, width: 400 mm, height: 50 mm) with a height of 15 m
It is filled up to the m position, press-molded using a pressing plate under the conditions shown in Table 1, and the obtained plate-shaped molded product is taken out from the mold,
Then, it was kept under the pre-curing conditions shown in Table 1. After pre-curing, an ultraviolet curable resin (manufactured by Showa Highpolymer Co., Ltd .: trade name T-350G) is applied to both surfaces of the molded product to cure it, and the molded product is dried and cured by holding it under curing conditions shown in Table 1. went.

Example 2 100 parts of Shirasu balloon, water glass (JIS No. 3 product)
104 parts, powdery water glass curing agent (condensed aluminum phosphate) 14 parts and reinforcing fiber (vinylon fiber, thickness 15μ)
m, length 6 mm) are uniformly mixed to obtain a granular material having a water content of 29%, and this mixture is then molded into a mold (length: 400 m).
m, width: 400 mm, height: 50 mm) with a height of 15 m
It is filled up to the m position, press-molded using a pressing plate under the conditions shown in Table 1, and the obtained plate-shaped molded product is taken out from the mold,
Then, it was kept under the pre-curing conditions shown in Table 1. After curing, the same ultraviolet curable resin as in Example 1 was applied to both surfaces of the molded body to cure the molded body, and the molded body was dried and cured under the curing conditions shown in Table 1.

Example 3 100 parts of Shirasu balloon, water glass (JIS No. 3 product)
156 parts, powdery water glass curing agent (condensed aluminum phosphate) 22 parts, reinforcing fiber (vinylon fiber, thickness 15μ)
m, length 6 mm) and a polymer binder (SB-based latex: solid content 50%) are uniformly mixed to obtain powder and granules having a water content of 31%.
400 mm, width: 400 mm, height: 50 mm) to a height of 15 mm, and press-molded using a pressing plate under the conditions shown in Table 1. The obtained plate-shaped molded product was taken out of the mold, And kept under the pre-curing conditions shown in Table 1. After curing, the same ultraviolet curable resin as in Example 1 was applied to both surfaces of the molded body to cure the molded body, and the molded body was dried and cured under the curing conditions shown in Table 1.

Comparative Example 1 A molded product was obtained in the same manner as in Example 1 except that the ultraviolet curable resin was not applied. Comparative Example 2 A molded body was obtained in the same manner as in Example 2 except that the ultraviolet curable resin was not applied. Comparative Example 3 A molded body was obtained in the same manner as in Example 3 except that the ultraviolet curable resin was not applied.

With respect to each molded product obtained as described above,
Visually observe the occurrence of shrinkage deformation and cracks,
The results are shown in Table 1.

[0017]

[Table 1]

Claims (2)

[Claims] 1. A plate-shaped molded product made of a cured product of a composition in which water glass and a water glass curing agent are mixed in a shirasu balloon, wherein a resin film is formed on both surfaces of the molded product. . 2. A composition in which shirasu balloon is mixed with water glass and a water glass curing agent is pressure-molded into a plate shape and pre-cured, and then resin films are formed on both surfaces of the obtained plate-shaped molded body. A method for producing a Shirasu balloon molded product, which comprises drying and curing.