JPH0570206A - Cement composite board and manufacturing method thereof - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] To provide a composite plate having excellent mechanical strength, fire resistance, and weather resistance, and an excellent manufacturing method by extrusion molding at low pressure. [Structure] Cement-containing W consisting of cement (A), water (B), vinyl monomer (C) and inverse emulsifier (D), and optionally reinforcing material (synthetic fiber, carbon fiber, etc.) (E) / O emulsion composition obtained by extrusion molding, wherein the weight ratio of cement (A) and water (B) in the emulsion composition is 100: 10 to 40. And the cement-containing W / O emulsion composition is molded at an extrusion pressure of 5 kg / cm ² or less.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cement composite board having excellent mechanical strength and a method for producing the same by extrusion molding.

[0002]

2. Description of the Related Art Conventionally, extruded cement boards have weather resistance,
It is excellent in fire protection and has a low manufacturing cost, so it is especially produced in large quantities as a building material. These extrusion molded cement plates are usually cement, silica sand, methyl cellulose, asbestos, after extrusion molding a clay-like material obtained by kneading by adding water to a mixture of lightweight aggregate as needed,
It was manufactured by curing by methods such as steam curing and autoclave curing.

However, in the case of such a method, if the amount of water used relative to the cement is increased, the formability and shape retention are poor, and conversely, if the amount of water used is reduced, then 20-50 k.
Since extrusion molding at a high pressure of g / cm ² or higher is required, there is a problem that not only abrasion and damage of the extruder increase but also extrusion molding speed does not increase. Furthermore, when a reinforcing material such as carbon fiber was added in order to improve the mechanical strength of the obtained extrusion molded cement board, the reinforcing material was significantly damaged due to the high pressure during extrusion molding, and a sufficient reinforcing effect was not obtained. .. Further, the use of synthetic fibers as a reinforcing material has a poor reinforcing effect due to its poor affinity with cement slurry, and normally, only a specific reinforcing material such as asbestos has been used.

On the other hand, the inventors of the present invention previously prepared a cement board obtained by molding a cement-containing W / O type emulsion obtained from a cement slurry, a vinyl monomer and a surfactant, and dispersed inside the emulsion. Dense voids are formed after the water is removed by evaporation, so a porous cement board can be easily obtained, and the vinyl monomer is a continuous layer and hardens to form a composite structure, so the strength is relatively high. It was clarified that a cement board can be obtained (Japanese Patent Publication No. 1-30778).
Japanese Patent Publication No. 2-16266, Japanese Patent Publication No. 2-11
544). Furthermore, a cement-containing W / O type emulsion in which reinforcing fibers are dispersed in the above composition is 3 kg / cm.
It has been found that extrusion molding can be performed even at a low pressure of ² or less (JP-A-1-176258).

According to this method, the cement is dispersed in the W / O type emulsion, and since the emulsion has a high thixotropy property, it has an advantage that it can be easily formed into a free shape. .. However, all of these methods are related to a porous lightweight cement board, and have a drawback that much energy and time are required to dry and remove water in the cement board. Further, the mechanical strength is not always sufficient because it has voids inside.

[0006] Therefore, it is strongly expected from various fields that an extrusion-molded cement board containing various reinforcing materials, which has few voids inside, and a manufacturing method for efficiently extrusion-molding it at a low pressure are established. It was requested.

[0007]

INDUSTRIAL APPLICABILITY The present invention has excellent mechanical strength, excellent fire resistance and weather resistance, can be freely formed into various shapes, and can be used as a base material in a wide range of fields such as building materials. It is an object of the present invention to provide a cement composite board and an excellent method for producing the same by extrusion molding.

[0008]

According to the present invention, there is provided a cement-containing W / O type emulsion composition comprising cement (A), water (B), vinyl monomer (C) and inverse emulsifier (D). In a cement composite board obtained by extrusion molding, the weight ratio of cement (A) and water (B) in the cement-containing W / O type emulsion composition is 100: 10 to 40. .. Is also provided,
There is provided the cement composite board, wherein the cement-containing W / O emulsion composition contains a reinforcing material (E), and further, the reinforcing material (E) is a synthetic fiber,
There is provided the above-mentioned cement composite board, which is carbon fiber, and further, the weight ratio of the cement (A) and the water (B) is 100: 10 to 40, and the cement (A) and the water (B) are provided. ), A vinyl monomer (C), and a reverse emulsifier (D) to prepare a cement-containing W / O type emulsion composition, and then 5 kg of the cement-containing W / O type emulsion composition.
Provided is a method for producing a cement composite board, which is characterized in that the molding is performed at an extrusion pressure of not more than / cm ² .

That is, in the present invention, since the amount of water (B) used relative to the cement (A) is extremely small,
A cement board having high specific gravity and high mechanical strength with few voids formed on the basis of water dispersed in the W / O type emulsion composition can be obtained. Furthermore, the water used (B)
Since most of the water is consumed in the hydration reaction of the cement (A), the step of drying and removing the unreacted water (B) in the cement plate after molding can be omitted. This is
It is extremely industrially advantageous because the energy cost can be reduced.

The cement composite board of the present invention will be described in more detail below. Cement (A) used in the present invention
Examples thereof include silicate compounds such as Portland cement, blast furnace cement, fly ash cement, silica cement, alumina cement, and silica, and calcium compounds. These may be used alone or in combination.

The vinyl monomer (C) may be any compound as long as it has a low solubility in water and can form an emulsion with water and has a polymerizable double bond in the molecule, such as styrene and α-methyl. Aromatic vinyl monomers such as styrene, or (meth) such as ethyl acrylate, methyl methacrylate, hydroxypropyl methacrylate, etc.
Acrylic acid ester and acrylonitrile are mentioned.
Other examples include divinylbenzene, ethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, epoxy methacrylate and unsaturated polyester resins having two or more polymerizable double bonds in the molecule. These may be used alone or in combination of two or more. Particularly, of these, a mixture containing styrene as a main component is preferable from the viewpoint of economy and emulsion forming property. In addition, it is generally preferable to partially use a compound having two or more polymerizable double bonds in the molecule in order to improve the strength and polymerization characteristics of the obtained molded product.

A polymerization catalyst is mixed in the vinyl monomer (C) in order to accelerate the curing and curing reaction after molding. As the polymerization catalyst, a radical polymerization initiator such as a general organic peroxide or The redox catalyst is used according to the usual recipe.

The reverse emulsifier (D) is not particularly limited as long as it forms a W / O type emulsion, but sorbitan sesquioleate, sorbitan monolaurate, glycerol monostearate, sorbitan monooleate, diethylene glycol monostearate, Nonionic surfactants such as sorbitan monostearate, diglycerol monooleate, maleic anhydride adducts of alkylene glycols, neutralized products of polyalkylenepolyamines or alkyliminobisalkyleneamines, or mixtures thereof with higher fatty acids. , An ionic surfactant or a complex of an ionic surfactant. Among these, polyalkylene polyamines or neutralized products of alkyliminobisalkyleneamines, which require a relatively small amount of inverse emulsifier (D) and can form a stable emulsion even with a small amount of water (B), Alternatively, an ionic surfactant such as a mixture of them and a higher fatty acid or a complex of an ionic surfactant is particularly preferable. These may be used alone or in combination of two or more. Also, a reverse emulsifier (D)
Is used in an amount of 3 to 50% by weight based on the vinyl monomer (C). As a method of use, it is usually dissolved in the vinyl monomer (C) before use, but may be added separately.

Further, in the present invention, a reinforcing material (E) may be contained in the cement-containing W / O type emulsion composition for the purpose of obtaining a cement composite board having further excellent mechanical strength. As the reinforcing material (E), synthetic fibers such as polypropylene, polyester, vinylon, nylon, acrylic, aramid, polyethylene and vinyl chloride,
Inorganic fibers such as carbon fibers, glass fibers, metal fibers and mineral fibers, and whiskers such as silicon carbide and silicon nitride can be used. The shape of these reinforcing materials (E) is not particularly limited, but those having a length of less than 20 mm are preferable in view of extrusion molding. The mixing ratio of the reinforcing material (E) is 0.3 to 20 with respect to the cement-containing W / O type emulsion.
wt% is preferred.

In the present invention, since the vinyl monomer (C) forms a continuous layer and the cement (A) and water (B) are dispersed therein, the conventional raw material composed of cement-water-soluble polymer compound is used. Compared to the composition, the surface has remarkably high affinity with lipophilic synthetic resin-based reinforcing materials and carbon fibers,
The reinforcing material (E), which has been difficult to use in the past, can be easily and uniformly dispersed in the system. Further, the mixing ratio of the asbestos fiber is far smaller than that of the conventional asbestos fiber, and the excellent reinforcing effect can be exhibited. This is also one of the features of the present invention.

Next, a method for manufacturing the cement composite board of the present invention will be described. First, in the present invention, a cement-containing W / O type emulsion consisting of cement (A), water (B), vinyl monomer (C) and inverse emulsifier (D) is first produced. It is important to set the weight ratio of (A) and water (B) to 100: 10-40. In the production of a cement board by the conventional extrusion molding method, since the cement is dispersed in water or a water-based binder, the viscosity of the system increases as the amount of water used decreases, and therefore a high extrusion pressure is required. However, the greatest feature of the present invention is that good extrudability can be maintained even when the amount of water (B) used is small. When the amount of water (B) used with respect to the cement (A) exceeds 40, the voids in the obtained cement composite plate increase and the mechanical strength decreases, and it is necessary to dry and remove the excess water (B) later. Is not preferred because Further, if the amount of water (B) used is too small, not only the essential emulsion is not formed, but also the hydration reaction of the cement (A) does not proceed sufficiently, so that the mechanical strength of the obtained cement composite plate decreases conversely. Not preferable.

The amount of vinyl monomer (C) used is 1 to 20 wt% with respect to the total amount of cement (A) and water (B).
Is preferable, and particularly 2 to 10 wt% is preferable. If the amount of the vinyl monomer (C) used exceeds 20 wt%, not only the cost will increase, but also the fire resistance of the obtained cement composite plate will decrease, which is not preferable, and conversely if the amount used is less than 1 wt%. It is not preferable because the amount of cement (A) dispersed in the W / O type emulsion becomes too large and it becomes difficult to obtain a uniform emulsion.

The cement-containing W / O type emulsion composition comprises, for example, a vinyl monomer solution containing cement (A), water (B), a vinyl monomer (C), a reverse emulsifier (D) and a polymerization catalyst. In addition, it can be obtained by mixing with a commercially available mixer or continuous kneader. Depending on the mixing device, a cement-containing W / O type emulsion composition that is insoluble in viscous and soft clay-like water is usually obtained by stirring and mixing for 0.5 to 5 minutes.

When the reinforcing material (E) is contained, it may be added together with other raw materials before the cement-containing W / O type emulsion is formed, or the cement-containing W may be added.
You may mix in after / O type emulsion formation. In either mixing method, the reinforcing material (E) is easily and uniformly dispersed.

The cement-containing W / O type emulsion composition formed by the method described above is extruded at a low pressure of 5 kg / cm ² or less by an extruder equipped with a molding die. This is possible for the first time because the cement-containing W / O type emulsion composition has high thixotropy. That is, it has a property that it easily flows when a force is applied from the other, but the shape does not easily collapse when it is allowed to stand, so that it has high fluidity during kneading and extrusion molding.
Extrusion molding can be carried out at a low pressure of kg / cm ² or less, and since the shape does not collapse after extrusion molding, it can be extruded into a free shape.

Further, surprisingly, the above cement-containing W
Even when the reinforcing material (E) is contained in the / O type emulsion composition, the viscosity does not increase so much, and it can be extruded at a low pressure of 5 kg / cm ² or less as in the case where the reinforcing material (E) is not contained. I found it. This is due to the high lubricity of the vinyl monomer (C) constituting the matrix and the affinity with the reinforcing material (E), in addition to the properties of the cement-containing W / O type emulsion composition as an emulsion. Thought to be a thing. As described above, in the present invention, since extrusion molding can be carried out at a low pressure, it is possible to obtain an extrusion-molded cement composite board excellent in mechanical strength with little damage during extrusion molding of the reinforcing material (E).

Next, the extruded plate is subjected to a natural curing, a steam curing, and an autoclave curing to promote a polymerization reaction based on the double bond of the vinyl monomer (C) and a hydration reaction of the cement (A). The extrusion-molded cement composite board of the present invention thus obtained has a high mechanical strength because the amount of water (B) used is small and the voids in the cement board are small.
Also, the drying step for removing water after curing is water (B).
Most of it is consumed in the hydration reaction of the cement (A), so it can be omitted or shortened.

[0023]

The present invention will be described in detail with reference to the following examples. The raw materials used in this example are represented by the following symbols. (1) Cement A1 ... Portland cement: silica sand = 60 parts by weight: 4
0 parts by weight A2 ... Portland cement (2) Reverse emulsifier D1 ... 3.6 parts by weight of amide compound obtained by reacting 1 mol of tetraethylenepentamine with 1.5 mol of oleic acid and 2.4 parts by weight of dodecylbenzenesulfonic acid And a mixture of 4 parts by weight of oleic acid. D2 ... A mixture of a neutralized product of 4.2 parts by weight of an amide compound obtained in the same manner as D1 and 3.2 parts by weight of dodecylbenzenesulfonic acid, and 2 parts by weight of oleic acid. D3 ... Neutralized product of 4 parts by weight of an amide compound obtained by reacting 1 mol of iminobispropylamine and 0.7 mol of capric acid and 4 parts by weight of a phosphoric acid esterified product of 2-ethylhexanol, and 2 parts by weight of oleic acid. Mix of parts. D4 ... Sorbitan monolaurate D5 ... Sorbitan monooleate D6 ... Diglycerol monooleate (3) Polymerization catalyst I1 ... t-Butyl perbenzoate I2 ... t-Butyl peroxyisopropyl carbonate I3 ... Benzoyl peroxide (4) Reinforcing material E1 ... Polyacrylonitrile fiber (diameter 18μ, length 2
mm) E2 ... Polyacrylonitrile fiber (diameter 18μ, length 5)
mm) E3 ... polypropylene fiber (diameter 18 μ, length 6 mm) E4 ... InorPhil (amorphous mineral fiber produced by melting slag at high temperature, diameter 4 μ, length less than 1 mm, La
xa) E5 ... Glass fiber (diameter 13.5 μ, length 5 mm) E6 ... Carbon fiber (diameter 18 μ, length 10 mm) Further, the bending strength of the obtained cement composite plate is JIS-A.
It is shown by the result measured based on 1408.

Example 1 A continuous extruder having a continuous kneader, a vacuum chamber and an extrusion screw having a maximum processing capacity of 0.6 ton / hour was used, 229 kg / hr of Portland cement, 152.7 kg / hr of silica and water. 118.3 kg / hr,
And styrene monomer 85 as vinyl monomer (C)
Parts by weight, a reverse emulsifier (D) consisting of a mixture of 9 parts by weight of dodecylbenzenesulfonic acid neutralized product of tetraethylenepentamine oleic acid amide and 6 parts by weight of oleic acid, t-butylperoxybenzoate 1 as a polymerization catalyst 14.5 kg / of vinyl monomer solution obtained by mixing polymerization parts
An extrusion-molded plate having a width of 455 mm and a thickness of 12 mm was obtained by continuous quantitative supply with an hr. The extrusion pressure at this time is 2 kg / cm ²
It was below. This molded plate was cured and cured to obtain the cement composite plate of the present invention. The raw material composition is shown in Table 1, and the production conditions and characteristics are shown in Table 2.

Example 2 Using the same continuous extruder as in Example 1, a cement composite board was obtained in the same manner as in Example 1 except that the composition of raw materials shown in Table 1 was used. The production conditions at this time and the characteristics of the obtained cement composite board are shown in Table 2.

[0026]

[Table 1] (Note) The left end of the vinyl monomer solution column shows the amount used as a vinyl monomer solution consisting of styrene monomer, reverse emulsifier, and polymerization catalyst, and the right column shows the composition ratio in the vinyl monomer solution. Is shown.

[0027]

[Table 2]

Examples 3 to 10 and Comparative Examples 1 to 2 In a continuous extruder similar to that of Example 1, based on the raw material composition shown in Table 3, cement, water, a reinforcing material, and a vinyl monomer were used. The vinyl monomer solution obtained by mixing the styrene monomer, the reverse emulsifier, and the polymerization catalyst was continuously supplied in a fixed amount to obtain an extruded plate having a width of 455 mm and a thickness of 18 mm. The extrusion pressure at this time was 2 kg / cm ² or less. This molded plate was cured and cured to obtain the cement composite plate of the present invention.
Table 4 shows the production conditions and the properties of the obtained cement composite board at this time.

[0029]

[Table 3] (Note) The left end of the vinyl monomer solution column shows the amount used as a vinyl monomer solution consisting of styrene monomer, reverse emulsifier, and polymerization catalyst, and the right column shows the composition ratio in the vinyl monomer solution. Is shown.

[0030]

[Table 4]

As is clear from Examples 1 and 2 and Comparative Examples 1 and 2, the bending strength of the cement composite plates obtained in Comparative Examples is the same as that of the Examples even though the reinforcing material (E) is used. It is lower than the bending strength of the cement composite board obtained in. Moreover, in Examples 3 to 10, the bending strength of the cement composite plates obtained from the fact that the W / O type emulsion and the reinforcing material (E) have a good affinity shows a considerably high value. This means that the amount of water (B) used is reduced so that the ratio of cement (A) to water (B) is 100: 10 to 40, and the reinforcing material (E) is used as in the present invention. This indicates that a cement composite board with improved mechanical strength such as bending strength can be obtained. Moreover, it is not necessary to dry the extruded plate after curing it. Further, in the present invention, as is clear from the examples, the extrusion pressure is as low as ² kg / cm ² even when the amount of water (B) used is small.

[0032]

The cement composite board of the present invention has a small amount of water (B) with respect to the cement (A) and therefore has few voids inside and is excellent in mechanical strength. In the present invention, the cement composite board can be obtained by an extrusion molding method using a W / O type emulsion. Moreover, the W
/ O type emulsion has high thixotropy and W /
Due to the high lubricity of the vinyl monomer forming the matrix of the O-type emulsion, extrusion molding can be performed at a low pressure of 5 kg / cm ² or less even when the amount of water (B) used is small. Further, since it has an excellent affinity with synthetic fibers, carbon fibers, etc., they can be easily and uniformly dispersed, and since the extrusion pressure is low, the reinforcing material (E) is less likely to be damaged during extrusion. It also has an effect.

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Claims (5)

[Claims] 1. A cement-containing W / containing cement (A), water (B), vinyl monomer (C) and inverse emulsifier (D).
In a cement composite board obtained by extrusion molding an O-type emulsion composition, the weight ratio of cement (A) and water (B) in the cement-containing W / O-type emulsion composition is 100:
It is 10-40, The cement composite board characterized by the above-mentioned. 2. The cement composite board according to claim 1, wherein the cement-containing W / O type emulsion composition contains a reinforcing material (E). 3. The cement composite board according to claim 2, wherein the reinforcing material (E) is a synthetic fiber or a carbon fiber. 4. The weight ratio of cement (A) to water (B) is 1.
A cement-containing W / O type emulsion composition comprising 00:10 to 40 and comprising cement (A), water (B), vinyl monomer (C) and inverse emulsifier (D), and then containing cement 5 kg of W / O type emulsion composition
A method for producing a cement composite board, which comprises molding at an extrusion pressure of not more than / cm ² . 5. The method for producing a cement composite board according to claim 4, wherein the cement-containing W / O type emulsion composition contains a reinforcing material (E).