JP2574212B2 - Method and apparatus for producing inorganic plate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cement-based inorganic plate mainly used for construction.

[0002]

2. Description of the Related Art Conventionally, an inorganic plate in which a wood reinforcing material such as a piece of wood, wool, or wood pulp is mixed with cement has been provided as a building plate such as an outer wall material or an inner wall material. The inorganic plate is obtained by mixing a wood reinforcing material with a cement-based inorganic powder such as cement,
The mixture is filled in a template, heated and pressed to produce a molded product, and then the molded product is removed from the mold and cured.

[0003]

However, in the above-mentioned conventional manufacturing method, although the hardening of the cement-based inorganic powder is promoted by heating and pressing, it takes 8 to 10 days after the pressing to release the mold. This requires a long period of time, and the productivity is very low (for example, Japanese Patent Application Laid-Open No. 54-48).
No. 821). The reason why it takes a long time before demolding after pressing is that cement-based inorganic powders require a long time for hydration and hardening, and when demolded in a short time, the molding material causes springback. It is mentioned that a molded article having a desired shape cannot be obtained. In particular, when the saccharides contained in the wood act on the cement-based inorganic powder, the hardening of the cement-based inorganic powder is inhibited, and the curing time is further delayed, often resulting in poor curing and making molding impossible. However, from the viewpoint of effective use of wood resources, it is desirable to use wood scrap generated by demolition of buildings as a wood reinforcing material. However, the wood scrap contains a tree species containing a large amount of the saccharides. It is very troublesome to select and remove only such tree species. Furthermore, even if it is the same tree species, there is a problem that the sugar content differs between the core material and the sapwood, and the time from press molding to demolding varies greatly. Therefore, the type of wood reinforcement or core material,
There has been a long-awaited demand for a method for manufacturing an inorganic plate that shortens the time from press forming to demolding and keeps it substantially constant regardless of the sapwood.

[0004]

According to the present invention, as a means for solving the above-mentioned conventional problems, a molding material comprising a mixture mainly composed of a cement-based inorganic powder and a wood reinforcing material is prepared by using carbon dioxide gas or carbonate ions. One to three or more kinds of compounds that can be generated are mixed with 3 to 50 parts by weight with respect to 100 parts by weight of the cement-based inorganic powder, and then deposited on a mold plate and pressed. A method for producing an inorganic plate for generating carbon dioxide or carbonate ions from the compound by heating and / or supplying water, and a lower press plate, an upper press plate, and steam between the lower press plate and the upper press plate. And a means for injecting the same.

[Cement-based inorganic powder] The cement-based inorganic powder used in the present invention is a hydraulic inorganic powder containing calcium silicate as a main component. For example, Portland cement, or blast furnace cement in which blast furnace slag is mixed with Portland cement,
Fly ash cement mixed with fly ash, silica cement mixed with silica substances such as volcanic ash and clay,
There are alumina cement, blast furnace slag and the like.

[Wood reinforcement] Wood reinforcement, wood wool, wood chips, wood fiber, wood pulp, wood fiber bundle, etc. are used as wood reinforcement in the present invention. A material containing lignocellulose as a main component such as fiber, bacas, fir, rice straw, etc. may be mixed. Preferred wood reinforcements are wood chips of 0.5 to 2.0 mm in width, 1 to 20 mm in length, 20 to 30 aspect ratios (length / thickness), 0.1 to 2.0 mm in diameter, and 2 to 35 mm in length. And / or bent and / or bent wood fiber bundles. The above-mentioned wood reinforcing material is usually added in a dry state in an amount of about 10 to 35% by weight based on the total solid powder of the mixture.

[Aggregate] In the present invention, an aggregate, particularly a lightweight aggregate, may be added in addition to the cement-based inorganic powder and the wood reinforcing material. As the above-mentioned aggregate, for example, silica sand, silica stone powder and the like are used, and as the above-mentioned lightweight aggregate, pearlite, shirasu balloon, expanded shale, expanded clay, calcined diatomaceous earth, fly ash, coal waste and the like are used. The above aggregate is usually added in an amount of about 5 to 15% by weight based on the total solid powder of the mixture.

[Third component] If desired, the above composition may further contain a hardening accelerator such as aluminum sulfate, magnesium sulfate, calcium sulfate, aluminates, water glass, or a wax,
A waterproofing agent such as wax, paraffin, a surfactant, and silicone, a water repellent, and the like may be added.

[Compound capable of generating carbon dioxide or carbonate ion] The compound capable of generating carbon dioxide used in the present invention is capable of generating carbon dioxide upon heating. Compounds include alkali metal, alkaline earth metal and ammonium bicarbonate. Magnesium carbonate normal salt generates carbon dioxide gas when heated in the presence of moisture. The compound capable of generating a carbonate ion used in the present invention is a compound that dissociates upon contact with water to generate a carbonate ion. Examples of such a compound include an alkali metal except for a normal salt of magnesium carbonate, There are alkaline earth metal or ammonium carbonate. When the compound is heated to a predetermined temperature when brought into contact with water, dissociation is promoted. Desirable alkali metals are sodium, potassium and lithium, and desirable alkaline earth metals are calcium, barium and magnesium. Rubidium among alkali metals,
Cesium, francium and the like, and among alkaline earth metals, strontium, radium, beryllium and the like are expensive and disadvantageous from an economical point of view, and calcium carbonate and barium carbonate are hardly soluble in water and hardly generate carbonate ions. Two or more of the above compounds may be used in combination, and usually 3 to 50 parts by weight based on 100 parts by weight of the cementitious inorganic powder,
Desirably, 5 to 30 parts by weight is blended.

[Manufacture of Inorganic Plate] In order to manufacture the inorganic plate of the present invention, a mat is formed by depositing a molding material comprising a mixture obtained by mixing a predetermined amount of the above composition on a mold, and pressing the mat. Then, the molding material forming the mat is heated and / or supplied with water to generate carbon dioxide gas or carbonate ions from a compound capable of generating carbon dioxide gas or carbonate ions, and then molded. The temperature applied in the heating and pressing is usually 80 to 160 ° C., and it is preferable to supply and heat the water by using steam. When the steam is supplied, the pressure is usually set to 0 gauge. .025 to 1.5 MPa
And the injection time is usually 0.25 to 10 seconds. After the above compression molding, the obtained molded product is usually cured naturally. The curing condition is usually 7 to 10 days. It is preferable to cover the molded product with a water-impermeable film in order to normally prevent evaporation of water. In order to shorten the curing time, the humidity is 90% RH and the temperature is 5%.
Heat curing at 0 to 80 ° C. for 8 to 10 hours may be performed. After curing, the product undergoes a surface treatment through a drying process. The inorganic plate of the present invention may have a two-layer structure or a three-layer structure. In the case of a two-layer structure, first, a molding material in which a wood reinforcing material having a fine particle diameter is mixed is deposited on a template,
Next, a molding material in which a wood reinforcing material having a large particle diameter is mixed thereon is deposited on a template to form a mat having a two-layer structure, and the mat is heated and pressed to reinforce the wood having the fine particle diameter. A surface layer portion having a dense structure is formed by a molding material in which a material is mixed, and a back layer portion having a coarse structure is formed by a molding material in which a wood reinforcing material having a large particle diameter is mixed. Further, in the case of a three-layer structure, a molding material in which a wood reinforcing material having a fine particle diameter is mixed is further deposited thereon to form a three-layer mat, and the mat is heated and pressed to obtain the above-described particle diameter. The layer made of the molding material in which the wood reinforcing material having a large particle size is mixed is used as the core layer portion, and the layer made of the molding material in which the wood reinforcing material having a small particle diameter is mixed is used as the back layer portion. When a three-layered structure is formed, two mats having the two-layered structure may be stacked and heated and pressed. In this case, the mat is laminated so that layers of a molding material mixed with a woody fiber having a large particle diameter are in contact with each other.

[0011]

When a molding material comprising the above mixture is deposited on a mold plate, pressed and molded, and heated with steam or the like, a compound capable of generating carbon dioxide contained in the molded product is as follows. Reacts with calcium hydroxide in cement. In the case of alkali metal bicarbonate 2AHCO ₃ → A ₂ CO ₃ + H ₂ O + CO ₂ CO ₂ + Ca (OH) ₂ → Ca CO ₃ + H ₂ O A ₂ CO ₃ + Ca (OH) ₂ → Ca CO ₃ + 2AOH where A Is an alkali metal. The Ca CO ₃ thus generated precipitates in the matrix of the molded product and fills the voids in the matrix to improve the primary strength of the molded product. Furthermore, AOH by-produced becomes a curing accelerator for cement, and accelerates the curing of the molded product. In the case of alkaline earth metal bicarbonate, M (HCO ₃ ) ₂ → MCO ₃ .H ₂ O + CO ₂ CO ₂ + Ca (OH) ₂ → Ca CO ₃ + H ₂ O MCO ₃ + Ca (OH) ₂ → Ca CO ₃ + M ( OH) ₂ where M is an alkaline earth metal. Thus, even in the case of an alkaline earth metal, the generated Ca CO ₃ precipitates in the matrix of the molded product. In the case of ammonium bicarbonate NH ₄ HCO ₃ → NH ₃ + H ₂ O + CO ₂ CO ₂ + Ca (OH) ₂ → Ca CO ₃ + H ₂ O In the case of magnesium carbonate normal salt 4 Mg CO ₃ + 4H ₂ O → ₃ Mg CO ₃ · Mg (OH) _2.
3H ₂ O + CO ₂ The basic magnesium carbonate produced by the above reaction has self-hardening properties and precipitates in the matrix to improve the primary strength of the molded product. In the case of alkali metal carbonate A ₂ CO ₃ + 2H ₂ O → ₂ AOH + H ₂ CO _{3 In} the case of alkaline earth metal carbonate MCO ₃ + 2H ₂ O → M (OH) ₂ + H ₂ CO _{3 In} the case of ammonium carbonate (NH ₄ ) _{2 CO 3 + 2H 2 O → 2NH} 4 OH + H 2 CO 3 H 2 CO 3 generated by the above reaction is further reacted with calcium hydroxide in the cement according to the following reaction. H ₂ CO ₃ + Ca (OH) ₂ → Ca CO ₃ + 2H ₂ O Ca CO ₃ generated by the above reaction precipitates in the matrix of the molded product. However, if the amount of the compound is less than 3 parts by weight based on 100 parts by weight of the cementitious inorganic powder, such an effect is not remarkable, and 5
If the amount exceeds 0 parts by weight, the water absorption of the molded article increases, and the dimensional stability and the frost damage resistance deteriorate.

[0012]

【Example】

[Embodiment 1] FIGS. 1 to 5 show one embodiment of a process for producing an inorganic plate of the present invention. In FIG. 1, a mold plate (1) is conveyed by a conveyor (2) in the direction of an arrow, and a mold release agent is sprayed from a spray nozzle (3) on a mold surface of the mold plate (1). 1) is introduced into the forming device (4) by the conveyor (2). The forming device (4) is opposed to a forming chamber (5), a blower (7) provided inside a blower (6) provided at an outlet of the forming chamber (5), and the blower chamber (7). A reverse blower (8) provided at an inlet of the forming chamber (5), a hopper (9) provided at a ceiling of the forming chamber (5), and a molding material supply conveyor (5) connected to the hopper (9); 10),
A molding material supply sieve (11) installed on the conveyor (10).

The molding material R is sprayed from the sieve (11) onto a conveyor (10) and is supplied to a hopper of a forming chamber (5).
From (9) into the forming chamber (5),
It is scattered and deposited on the template (1) introduced by the conveyor (2) into the forming chamber (5). At this time, air is blown from the blower (6) of the blower chamber (7) to the inlet side, the molding material R is selected by air, and the molding material R in which the wood reinforcing material having a fine particle diameter is mixed is placed on the lower side. The molding material R in which the wood reinforcing material having a large size is mixed is set to the upper side. At this time, the reverse air is blown to the outlet side by the reverse air blower (8). So that In this way, a mat (12) having a dense structure on the lower side and a coarse structure on the upper side is formed, and the mat (12) is trimmed to a predetermined size, if necessary, and then the manufacturing apparatus (13) shown in FIG. ).

The manufacturing apparatus (13) includes a platen (15) installed on a base (14) and a lower pressure plate (16) which is a hot platen placed on the platen (15). ), A movable plate (18) attached to the lower end of the hydraulic cylinder (17), an upper pressurizing plate (19) which is a hot plate attached below the movable plate (18), and A steam injection plate (20) mounted below the platen (19),
A seal frame member (22) which is a seal means disposed below the steam injection plate (20) and suspended by a link (21).
And a frame (23) that supports the hydraulic cylinder (17) and guides the movable plate (18). The above steam injection board (20)
As shown in FIG. 3, is a main body (24), a steam pipe (25) inserted into the main body (24), and a number of nozzles which are inserted from the steam pipe (25) and open on the lower surface of the main body (24). It consists of a pipe (26).

The mat (12) formed by the above-mentioned forming device (4) is introduced into the manufacturing device (13), and is placed between the lower pressing plate (16) and the upper pressing plate (19) as shown in FIG. And the periphery thereof is sealed with a seal frame member (22). The pressing pressure in this case is usually 2 to 5 MPa. The lower pressure plate (16) and the upper pressure plate (19) are usually heated to a range of 80 to 160 ° C. by steam or electric heating,
Then, when the predetermined pressing pressure is reached, the steam injection plate (20)
Then, steam is injected into the molded product (27) through a steam pipe (25) and a nozzle pipe (26). As described above, the pressure of the water vapor is usually 0.025 to 1.5 MPa as a gauge pressure.
a, The injection time is usually 0.25 to 10 seconds. In this case, a releasable net or mat, such as a glass fiber net coated with Teflon resin, may be interposed between the mat (12) and the steam jet plate (20) so that steam can pass through. Further, instead of the sealing frame member (22), a sealing means such as a rubber belt or a heat-resistant adhesive tape may be used for sealing.

[0016] As described above, the voids in the matrix of the molded article (27) are filled with CaCO ₃ by spraying steam on the molded article (27), and the primary strength is improved in a short time (usually within 5 minutes). I do. At this time, the hardening of the cement-based inorganic powder is promoted by the AOH by-produced. At this time, the molded product (2
When the periphery of 7) is sealed with a sealing frame material (22), the internal pressure increases and the decomposition reaction of alkali metal compounds Ca CO ₃ and A
The generation reaction of OH is promoted. The molded product (2
7) Since the primary strength is improved in a short time during the press forming, the upper pressing plate (19) is raised to open the mold, and the inorganic plate molded product (27) shown in FIG. Remove from mold.

In this embodiment, a mixture having the following composition (water content: 40% by weight) was used as a molding material. Porto Holland cement 60 parts by weight perlite 8 〃 Douglas fir chips * ₁ 38 〃 water 16 〃 * _1: width 0.5 to 2 mm, more in length 1 to 20 mm, an aspect ratio of 20 to 30, water content 50% by weight the mixture Molding material R was prepared by mixing 12 parts by weight of sodium hydrogen carbonate and 1 part by weight of paraffin emulsion. In this embodiment, sodium bicarbonate was added at a ratio of 20 parts by weight to 100 parts by weight of portland cement.

The manufacturing conditions in this embodiment are as follows. Heating temperature of lower pressure plate (16) and upper pressure plate (19) 1
00 ° C (steam) Clamping pressure 2.6MPa Steam injection time 1 second After steam injection, keep the 2.6MPa compression for 3 minutes, then gradually reduce the pressure for 30 to 40 seconds, then decompress and open the mold. The obtained molded product (27) was removed from the mold, subjected to natural curing for 10 days, and dried to prepare a sample of an inorganic plate.

[Example 2] In this example, the beech pine chips of Example 1 were replaced with building waste chips having a water content of 20% by weight, and water was further added. Was prepared.

Example 3 In this example, a sample of an inorganic plate was prepared in the same manner as in Example 1 except that the larch chips of Example 1 were replaced with larch chips having a water content of 50% by weight.

Example 4 In this example, a sample of an inorganic plate was prepared in the same manner as in Example 1 except that potassium hydrogen carbonate was used instead of sodium hydrogencarbonate of Example 1.

Embodiment 5 In this embodiment, a mixture of 6 parts by weight of sodium carbonate and 8 parts by weight of sodium hydrogencarbonate is used in place of sodium hydrogencarbonate alone of Example 1 to make the filler 6 parts by weight. Otherwise, a sample of the inorganic plate was prepared in the same manner as in Example 1.

Example 6 In this example, 10 parts by weight of sodium hydrogen carbonate and 16 parts by weight of an aqueous solution of magnesium hydrogen carbonate in carbon dioxide were used in place of sodium hydrogen carbonate alone of Example 1 in place of the added water. . In this embodiment, the total amount of sodium hydrogencarbonate and magnesium hydrogencarbonate was 18 parts by weight with respect to 100 parts by weight of portland cement. Otherwise, a sample of the inorganic plate was prepared in the same manner as in Example 1.

Example 7 In this example, 12 parts by weight of ammonium hydrogen carbonate was used in place of the sodium hydrogen carbonate of Example 1. In this embodiment, ammonium bicarbonate was added at a ratio of 20 parts by weight to 100 parts by weight of portland cement. Otherwise, a sample of the inorganic plate was prepared in the same manner as in Example 1.

Comparative Example 1 A comparative sample was prepared in the same manner as in Example 1 except that sodium bicarbonate was omitted and instead the amount of portland cement was increased to 72 parts by weight. In addition, the primary strength of the molded article was low, and the molded article collapsed upon demolding, so that it was impossible to produce a sample of the inorganic plate.

Comparative Example 2 The same procedure as in Example 1 was carried out except that 7 parts by weight of sodium carbonate and 20 parts by weight of sodium hydrogencarbonate were used, and portland cement was reduced to 52 parts by weight. To prepare a comparative sample. In this embodiment, the portland cement 10
That is, about 52 parts by weight of sodium carbonate and sodium bicarbonate were added to 0 parts by weight.

Comparative Example 3 In Example 1, the amount of sodium bicarbonate was changed to 1 part by weight, and instead of this, the amount of portland cement was increased to 71 parts by weight (100 parts by weight of portland cement). Sodium was added in a total amount of about 1.4 parts by weight), and the other samples were prepared in the same manner as in Example 1.

Physical properties test The physical properties of the samples prepared in Examples 1 to 5 and Comparative Examples 2 and 3 were measured, and the results are shown in Table 1.

[Table 1]

Referring to Table 1, Examples 1 to 5 of the present invention are shown.
The bending strength (primary strength) after compression
Is large, the handleability at the time of demolding is good, but in Comparative Example 1 in which the compound capable of generating carbon dioxide of the present invention is not added, the strength of the molded product is extremely small,
The sample of Comparative Example 2, which collapsed during demolding and in which the compound was added in excess of 50 parts by weight with respect to 100 parts by weight of portland cement, had reduced primary strength and final strength and reduced water absorption. It becomes remarkably large, and the dimensional change rate of water absorption and the frost damage resistance deteriorate. Further, in the sample of Comparative Example 3 in which the compound was less than 5 parts by weight based on 100 parts by weight of the portland cement, physical properties could not be measured.

[0030]

As described above, according to the present invention, an inorganic plate can be produced extremely efficiently and in a short time regardless of the material of the wood reinforcing material, and it is also possible to reuse waste building materials as the wood reinforcing material. .

[Brief description of the drawings]

 1 to 5 show one embodiment of the present invention.

FIG. 1 is a process chart of mat forming.

FIG. 2 is a schematic view of an inorganic plate manufacturing apparatus.

FIG. 3 is a schematic cross-sectional view of a steam injection board.

FIG. 4 is a schematic view of an apparatus for manufacturing an inorganic plate in a pressed state.

FIG. 5 is a side sectional view of a molded product.

[Explanation of symbols]

 1 Mold plate 12 Mat 13 Inorganic plate production equipment 16 Lower press platen 19 Upper press platen 20 Steam spray plate 22 Seal frame material 27 Molded product

Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI Technical display location C04B 40/02 C04B 40/02 // (C04B 28/02 18:26 14:18 22:10 24:26) 103: 14 111: 30 111: 40

Claims (8)

(57) [Claims] 1. A molding material comprising a mixture mainly composed of a cement-based inorganic powder and a wood reinforcing material, wherein one or two or more compounds capable of generating carbon dioxide or carbonate ions are added to the cement-based inorganic powder. 3 to 5 for 100 parts by weight
After mixing 0 parts by weight, it is deposited on a template and pressed,
A method for producing an inorganic plate, comprising heating the molding material and / or supplying moisture to generate carbon dioxide or carbonate ions from the compound. 2. The compound according to claim 1, wherein the compound is an alkali metal carbonate and / or
2. The method for producing an inorganic plate according to claim 1, which is a hydrogen carbonate. 3. The method according to claim 2, wherein said alkali metal is selected from sodium, potassium and lithium. 4. The method according to claim 1, wherein the compound is a carbonate and / or a hydrogen carbonate of an alkaline earth metal. 5. The method according to claim 4, wherein said alkaline earth metal is selected from calcium, barium and magnesium. 6. The compound according to claim 1, wherein the compound is ammonium carbonate and / or
2. The method for producing an inorganic plate according to claim 1, which is a hydrogen carbonate. 7. The method according to claim 1, further comprising a lower pressure plate, an upper pressure plate, and means for injecting steam between the lower pressure plate and the upper pressure plate. Inorganic plate manufacturing equipment 8. The apparatus according to claim 7, wherein sealing means for sealing a peripheral edge of said molding material is interposed between said lower press plate and said upper press plate.