JP2666893B2 - Composition for lightweight building material and method for producing lightweight building material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel composition for a lightweight building material and a method for producing a lightweight building material. More specifically, the present invention is excellent in workability such as nailing and sawing and fire resistance, and a composition that gives a lightweight building material, and a lightweight composition excellent in workability and fire resistance using the composition. The present invention relates to a method for efficiently producing a building material by a papermaking method.

[0002]

2. Description of the Related Art Conventionally, as a lightweight building material, a material obtained by mixing a lightweight foamed aggregate or a fibrous substance with cement, gypsum or slag slag, and forming it by a papermaking method into a plate shape is known.

[0003] However, all of these plate-like bodies have some drawbacks and cannot be said to be practically satisfactory as building materials. For example, asbestos cement board has the advantage of high flexural strength, but has the drawback of high specific gravity and low impact strength.In addition, asbestos fibers are considered harmful to the human body, and their use has been limited in recent years. Tend to

[0004] Further, the pulp cement board has the advantage that it is lightweight and has good workability, but since it has a large expansion rate and contraction rate, it will crack when used in places where the climate changes significantly. There is a disadvantage that it is easy to occur. Furthermore, the gypsum board has a drawback of low bending strength and poor water resistance, and the slag slag board has a drawback of high specific gravity and poor workability such as nailing and sawing.
On the other hand, those using lightweight foam aggregates such as perlite,
These are damaged in the pressurizing step at the time of manufacturing, and sufficient weight reduction cannot be achieved.

[0005] Thus, in the conventional building materials, specific gravity, strength,
In terms of expansion / contraction, fire resistance, workability, production efficiency, economic efficiency, etc., it has not yet been known that they meet the practical standards at the same time. Has become an important issue.

On the other hand, rice husks generated during threshing of rice are:
Despite being discharged as a large amount of agricultural waste every year, the fact is that only part of it is used as fuel, and it is incinerated or discarded almost unused. Therefore, research has been conducted to utilize this as a raw material for some time.For example, paying attention to the point that its component contains silicic acid, white ash obtained by completely burning it was mixed with lime powder. To produce lightweight refractory building materials by hydrothermal reaction. However, in this method, the rice ash must be prepared under strictly controlled conditions in order to maintain the quality of the rice ash at a predetermined standard, and furthermore, the production process requires many steps, and the cost is high. It is unavoidable that it is not practical.

[0007]

Under the circumstances described above, the present invention utilizes the chaff that has been discarded until now, such as nailing and sawing, and fire resistance. The object of the present invention is to easily produce a lightweight building material having excellent flexibility and appropriate bending strength.

[0008]

[Means for Solving the Problems] The inventors of the present invention have conducted diligent research to develop a method for manufacturing a lightweight building material by utilizing chaff and black chaff ash remaining after using the chaff. As a result of stacking, ash obtained by incomplete burning of rice husks and black ash with a high carbon content such as black ash remaining after using rice husks as fuel are used as cement, fibrous materials and homogenizers. Mixed with water, and added water to form an aqueous slurry, and found that a plate-like body obtained by molding by a papermaking method had suitable physical properties as a lightweight building material, and based on this finding, came to the present invention. .

That is, the present invention relates to (A) cement 10
0 parts by weight, (B) 25 to 150 parts by weight of rice ash having a carbon content of 2.5 to 7% by weight, (C) 10 to 40 fibrous substances
By weight, and (D) 5 to 15 parts by weight of a homogenizing agent, a composition for a lightweight building material comprising an aqueous slurry, and the aqueous slurry are formed into a plate shape, then cured and dried. An object of the present invention is to provide a method for producing a lightweight building material, wherein the moisture content is adjusted to 10% by weight or less.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The composition for a lightweight building material of the present invention comprises:
It comprises an aqueous slurry containing (A) cement, (B) rice ash, (C) a fibrous substance, and (D) a homogenizing agent. Any of Portland cement, magnesia cement, alumina cement, mixed cement, natural cement and the like can be used alone or in combination of two or more.

[0011] Further, as the rice ash of the component (B),
Burn the rice husk of agricultural waste by-produced when threshing the polished rice according to the usual method, and carbon content is 2.5-7% by weight.
Use ash in the range of In addition, when husk is used as a fuel, black ash remains afterwards, but this ash usually contains 5 to 6% by weight of carbon and can be used as it is as the component (B) of the present invention. The carbon in the chaff ash contributes to the improvement of physical properties such as antistatic property, radio noise prevention property, and durability when used as a building material, but if this amount is less than 2.5% by weight, these physical properties are improved. Is hardly recognized. On the other hand, if the amount is more than 7% by weight, coloring is remarkable, and the commercial value of the building material is reduced.

[0012] In general, burning rice husks burns organic matter and leaves ash. The color of the ash changes with the combustion temperature, and burning at a high temperature without burning loss is necessary to obtain white ash. When the combustion temperature is low, the color turns black and the content of residual carbon increases. The ash obtained by burning at a temperature of about 400 to 700 ° C. is amorphous silica.
It is known that when fired at a temperature of about 00 to 1000 ° C., crystallization proceeds, and in this case, the type and color tone of the ash crystals vary depending on the atmosphere, temperature, and time during firing.

In the present invention, this rice ash does not utilize the chemical composition or color tone, but aims to utilize the lightness of the ash itself. In view of the above, the carbon content is 2.5
~ 7% by weight of black ash can be used as is.
It is advantageous to grind this chaff ash to obtain a particle size that passes through a 700 μm sieve, particularly a particle size that passes through a 300 μm sieve, because a lightweight and strong building material can be obtained.

The rice ash of the component (B) is 25 to 1 part by weight based on 100 parts by weight of the cement of the component (A).
It is blended in a proportion of 50 parts by weight. If the compounding amount is less than 25 parts by weight, the bulk density of the building material increases, and weight reduction is not achieved. If the compounding amount exceeds 150 parts by weight, the bending strength of the building material decreases and the papermaking property is significantly reduced. From the viewpoint of balance of light weight, bending strength and papermaking properties of building materials,
The preferred amount of the rice ash is in the range of 75 to 125 parts by weight.

In the composition of the present invention, examples of the fibrous substance used as the component (C) include synthetic fibers such as vinylon fiber and polypropylene fiber, mineral fibers such as glass fiber, carbon fiber, asbestos, rock wool and wollastonite. And synthetic fibers and vegetable fibers such as waste paper pulp such as newsprint, old magazines and cardboard. These may be used singly or in combination of two or more types, especially those in which pulp fiber is combined with at least one selected from synthetic fibers, glass fibers, carbon fibers and mineral fibers. Is preferred.

The fibrous substance of the component (C) is blended at a ratio of 10 to 40 parts by weight with respect to 100 to 100 parts by weight of the cement of the component (A) and 25 to 150 parts by weight of the rice ash of the component (B). Is done. If the blending amount is less than 10 parts by weight, a building material having sufficient bending strength cannot be obtained, and if it exceeds 40 parts by weight, the porosity of the resulting building material increases, so that the expansion / shrinkage ratio increases and the dispersibility increases. It tends to worsen and the strength tends to decrease. Bending strength of the resulting building material,
The amount of the fibrous substance is preferably in the range of 15 to 30 parts by weight from the viewpoints of expansion and contraction.

Examples of the homogenizing agent used as the component (D) include water glass, natural minerals, water-soluble fibrous materials, and water-soluble polymers. Here, the natural minerals include calcium metasilicate and hydrous magnesia minerals and alumina minerals, and the water-soluble fibrin materials include, for example, carboxymethyl cellulose, methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, and micro pulp. Examples of the water-soluble polymer include polyvinyl alcohol, partially saponified polyvinyl acetate, and polyvinylpyrrolidone. These homogenizing agents may be used alone or in combination of two or more.
In particular, when using natural minerals, in addition to the homogenizing effect,
This is advantageous because an effect of accelerating curing can be obtained.

The homogenizing agent of the component (D) is as described in the above (A)
It is blended at a ratio of 5 to 15 parts by weight based on 100 to 100 parts by weight of the component cement and 25 to 150 parts by weight of the rice ash of the component (B). When the amount is less than 5 parts by weight, a sufficient homogenizing agent effect cannot be obtained, and when the amount exceeds 15 parts by weight, the obtained building material has an increased bulk specific gravity and reduced workability. In view of the homogenizing effect, the bulk specific gravity of the obtained building material, the workability, and the like, the preferable amount of the homogenizing agent is 5.3 to 7.5.
It is in the range of parts by weight.

The method for preparing the composition for lightweight construction materials of the present invention is not particularly limited. For example, first, the fibrous substance of the component (C) is put into a mixer, water is added and stirred, and then () A) The cement of the component and the rice ash of the component (B) are added, and the homogenizing agent of the component (D) is further added and kneaded.
An aqueous slurry having a concentration suitable for papermaking is prepared. When preparing the aqueous slurry, a coagulant such as a curing accelerator or an anionic surfactant may be added, if desired. This aqueous slurry is advantageously adjusted to a solid concentration of 3.5 to 10% by weight.

Next, the method for producing a lightweight building material of the present invention will be described. First, the aqueous slurry prepared as described above is formed into a plate having a desired thickness by a papermaking method. This papermaking method is not particularly limited, for example, using a papermaking machine conventionally used in the production of asbestos cement board or pulp cement board, for example, a method of papermaking using a circular net, long net, short net, etc. Can be used. At this time, it is advantageous to adjust the roll pressure so that the water content of the plate-like molded body is about 40 to 55% by weight.

Next, the plate-shaped molded product thus obtained is subjected to natural curing for about 10 several days or steam curing at a temperature of about 60 to 80 ° C. for several hours to cure and cure, and then usually 100. At a temperature in the range of ~ 150 ° C, the water content is 10
Drying treatment is carried out until it becomes less than weight%.

In this way, a desired lightweight building material can be obtained.
Finishing can be performed by coloring, attaching decorative printing paper, and the like.

[0023]

According to the present invention, using the ash of agricultural waste, it is excellent in workability such as nailing and sawing and fire resistance, and has an appropriate bending strength and a normal bulk specific gravity of 1%. A lightweight building material of 0.0 or less, preferably 0.8 or less can be easily manufactured. This lightweight building material is suitably used, for example, as a ceiling material, a wall material, a heat insulating material, and the like.

[0024]

Next, the present invention will be described in more detail by way of examples, but the present invention is not limited to these examples.

The bending strength of the cured product was determined by the following method. Flexural strength measurement: Cured molded body width 4
The sample was cut into 0 mm and 160 mm in length to prepare a sample, and the sample was measured using an Autograph manufactured by Shimadzu Corporation with a centralized loading of 150 mm in span and 1 mm in loading speed per minute. The materials used are as follows. (A) Cement: ordinary Portland cement (B) Hull ash 300 μm Particle size through sieve, analysis value: SiO ₂ 9
1.8 wt%, C 5.4 wt%, Al ₂ O ₃ 0.9 wt%, Fe ₂ O ₃ 0.2 wt%, CaO 0.6 wt%, other 1.1% by weight (C) fibers Pulp: waste paper pulp (unwoven waste paper adjusted to a concentration of 5%) C-1: vinylon fiber [Kuraray Co., Ltd., fiber length 3 m
m] C-2: Asbestos (Chrysotile 6D class) C-3: Glass fiber (alkali resistance, fiber length 12 mm) (D) Homogenizer Milcon LS: Sepiolite, a natural hydrous magnesia mineral, manufactured by Showa Mining Co., Ltd. Wollastonite: Calcium metasilicate mineral (from China) (E) Others Die mix: Hardening accelerator, manufactured by Showa Mining Co., Ltd.

Example 1 First, 8.8 parts by weight of waste paper pulp, 5.3 parts by weight of vinylon fiber, and an appropriate amount of water were put into a mixer, stirred, and then mixed with 100 parts by weight of Portland cement, rice ash (containing carbon). 75 parts by weight, 5.3 parts by weight of Milcon LS, 10.0 parts by weight of Dymix, and a total water amount of 4 parts by weight.
Water was added to 10 parts by weight and kneaded for 5 minutes to prepare an aqueous slurry.

Next, using a sheet machine,
A mesh wire mesh is laid, filter papers are placed on the top and bottom of the wire mesh, and the aqueous slurry is formed into a desired shape by a papermaking method under the condition of a vacuum degree of 55 to 60 mmHg, and a pressure of 6 to.
The plate was pressed (10 kg / cm ² ) for 2 minutes at n. Next, this was kept in a moist air atmosphere at 20 ° C. for 20 hours, then heated to 80 ° C. at a rate of 15 ° C./hr, and further kept at 80 ° C. for 3 hours to perform steam curing. Then, it is dried at 105 ° C. for 6 hours,
A lightweight building material having a thickness of 0 mm, a width of 250 mm, and a thickness of 11.9 mm was manufactured. Table 1 shows the physical properties of the thus obtained lightweight building materials.

Example 2 An aqueous slurry was prepared in the same manner as in Example 1 except that asbestos was used instead of the vinylon fiber in Example 1, and the total amount of water was changed to 1020 parts by weight. Next, using this aqueous slurry, a lightweight building material was manufactured by the same papermaking method as in Example 1. Table 1 shows the physical properties of this lightweight building material.

Examples 3 and 4 100 parts by weight of cement, 100 parts by weight of chaff ash, 10.0 parts by weight or 16.0 parts by weight of waste paper pulp, 6.0 parts by weight of vinylon fiber, 6.0 parts by weight of Milcon LS, die An aqueous slurry was prepared using 10.0 parts by weight of the mix and adjusting the total water amount to 1200 parts by weight. next,
Using this aqueous slurry, a lightweight building material was manufactured by the same papermaking method as in Example 1. Table 1 shows the physical properties of this lightweight building material.

[0030]

[Table 1]

Examples 5 to 9 To 100 parts by weight of cement and 150 parts by weight of chaff ash, the components and amounts shown in Table 2 and water were added to prepare an aqueous slurry. Next, using this aqueous slurry, a lightweight building material was manufactured by the same papermaking method as in Example 1. Table 2 shows the physical properties of this lightweight building material.

[0032]

[Table 2]

Examples 10 to 13 Using 100 parts by weight of cement, 100 parts by weight of rice ash and 10 parts by weight of die mix, the amount of vinylon fiber and waste paper pulp shown in Table 3 were added thereto, and the total water content was 1200 parts by weight. An aqueous slurry was prepared as described above, and a length of 250 mm, a width of 200 mm,
A lightweight building material having a thickness of 12 mm was manufactured. Table 3 shows the physical properties of this lightweight building material.

[0034]

[Table 3]

Example 14 Waste paper pulp (80 kg in solid content) having a concentration of about 5% by weight was put into a mixer, and 8 kg of vinylon fibers (fiber length 6 mm) and 50 kg of wollastonite were added while circulating water by adding 5 times the amount of water. , 300g of fine pulp, 40k of die mix
g, rice ash 400 kg, Portland cement 40
0 kg was added and kneaded. Then, while gradually pumping up the kneaded raw material mixture, the mixture is further diluted with water to a concentration of about 4% by weight, and the paper is machined at a linear pressure of about 35 kg / cm ² using a circular mesh type paper machine to produce a green paper. The water content of the plate was adjusted to about 50% by weight, and the length was 180 cm and the width was 9 cm.
A plate-like molded body having a thickness of 0 cm and a thickness of 1.2 cm was produced. At this time, the concentration of the papermaking raw material was in the range of 3.5 to 5.0% by weight, and the linear pressure of the making roll was 30 to 45 kg.
/ Cm ² within the range of 40 to 55% by weight
, A plate-like molded product of almost the same quality was obtained.

The plate-shaped compact thus obtained was placed in a steam curing chamber, heated to 70 ° C. at a heating rate of 5 ° C. per hour, kept at this temperature for 4 hours, and then slowly cooled. And cured. Next, the cured product was dried at a temperature of 100 to 150 ° C. until the water content became 10% by weight or less to obtain a lightweight building material. The lightweight building material thus obtained has a specific gravity of 1.0 and a bending strength of 124.5 kg / cm ² , and does not show cracks or cracks even when subjected to processing such as sawing, nailing, and screwing. Was.

Example 15 The same procedure as in Example 14 was carried out except that a raw material mixture not containing 40 kg of die mix was used.
A lightweight building material having a bending strength of 112 kg / cm ² and excellent workability was obtained.

──────────────────────────────────────────────────続 き Continuation of the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical indication location C04B 16:02) 111: 30 111: 40 (72) Inventor Shin Suzuki 3 Senriyamanishi, Suita-shi, Osaka 5-2-1-516 (72) Koichi Kawamura 88 Kodai, Nagaokakyo City, Kyoto Prefecture Daiji Okuhara (56) References JP 59-83974 (JP, A) JP 61-242937 (JP, A) ) Special table Hei 7-506326 (JP, A)

Claims (8)

(57) [Claims] (A) 100 parts by weight of cement, (B) 25 to 150 parts by weight of rice ash having a carbon content of 2.5 to 7% by weight, (C) 10 to 40 parts by weight of fibrous substance, and (D) A) A lightweight building material composition comprising an aqueous slurry containing 5 to 15 parts by weight of a homogenizing agent. 2. The composition for a lightweight building material according to claim 1, wherein the rice ash (B) has a particle size of 300 μm through a sieve. 3. The fibrous substance as component (C) is pulp fiber or a mixture of pulp fiber and at least one selected from synthetic fiber, glass fiber, carbon fiber and mineral fiber. 2. The composition for lightweight building materials according to 2. 4. The method according to claim 1, wherein the homogenizing agent of the component (D) is at least one selected from water glass, natural minerals, water-soluble fibrils and water-soluble polymers. A composition for lightweight building materials. (A) 100 parts by weight of cement, (B) 25 to 150 parts by weight of rice ash having a carbon content of 2.5 to 7% by weight, (C) 10 to 40 parts by weight of fibrous substance, and (D) ) An aqueous slurry containing 5 to 15 parts by weight of a homogenizing agent is formed into a sheet and molded, then cured and dried to obtain a water content of 1%.
A method for producing a lightweight building material, wherein the weight is set to 0% by weight or less. 6. The method for producing a lightweight building material according to claim 5, wherein the chaff ash of the component (B) has a particle size of 300 μm passing through a sieve. 7. The fibrous substance of component (C) is pulp fiber or a mixture of pulp fiber and at least one selected from synthetic fiber, glass fiber, carbon fiber and mineral fiber. 6. The method for producing a lightweight building material according to 6. 8. The method according to claim 5, wherein the homogenizing agent of the component (D) is at least one selected from water glass, natural minerals, water-soluble fibrils and water-soluble polymers. Manufacturing method of lightweight building materials.