JPH11226925A - Hydraulic inorganic molding and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hydraulic inorganic molding which has a large porosity and is light in weight and good in strength and a method for producing the molding. SOLUTION: Slurry hydraulic inorganic raw material 7 which comprises 100 pts.wt. of hydraulic inorganic powder, 40-100 pts.wt. of silica inorganic fine powder, 1-10 wt.% of beaten cellulose fibers based on the total solid content, 0.1-1.0 wt.% of carbon fibers based on the total solid content, and the rest of water and in which the total solid content is 20-50 wt.% is molded by a flow-on method. The obtained raw molding is steam-cured and cured further in an autoclave to obtain a hydraulic inorganic molding 0.300-0.390 cc/g in porosity and at the lowest 90 m<2> in specific surface area.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a hydraulic inorganic molded article and a method for producing the same.

[0002]

2. Description of the Related Art As a method of continuously producing hydraulic inorganic molded articles mainly used for building materials such as roofing materials and wall materials, there is a Hatschek-type papermaking method. It has the weak point of causing delamination over time. Therefore, as a method of overcoming the weaknesses of the Hachek type papermaking method and producing a single-layer molded body, a method called a flow-on method, in which raw materials are supplied on a moving water-permeable sheet and developed, and A production method has been proposed in which dehydration under reduced pressure is carried out during the movement by suction means provided below, and excess water is squeezed out (JP-A-53-5421).
No. 9, etc.).

[0003] However, molded articles manufactured by the conventional flow-on method were insufficient in specific gravity and strength. That is, building materials such as roofing materials and wall materials are required to have lower specific gravity and higher strength from the viewpoint of weight burden on the building itself or workability.

[0004]

SUMMARY OF THE INVENTION In view of the above circumstances, the present invention provides a hydraulic inorganic molded article having a lower specific gravity and a higher strength and a method of manufacturing the same, which does not cause delamination deterioration. It is intended to provide.

[0005]

In order to achieve the above object, a hydraulic inorganic molded article according to the present invention comprises a hydraulic inorganic powder containing a hydraulic inorganic powder, a silica inorganic fine powder, and a beaten cellulose fiber. The raw material was molded and cured, had pores having a pore volume of 0.300 cc / g or more and 0.390 cc / g or less, and had a specific surface area of 90 m ² / g or more.

In the present invention, the porosity is 0.300 cc / g.
More than 0.390cc / g or less, the porosity is 0.300c
If it is less than c / g, the structure of the compact becomes too dense and the specific gravity of the compact increases.If the pore volume exceeds 0.390 cc / g, the structure of the compact becomes coarse, resulting in insufficient initial strength or durability. It will be inferior. In addition, the specific surface area is 90 m ² / g
Limited to the above, when the specific surface area is less than 90 m ² / g,
This is because the initial strength is insufficient or the durability is poor.

Further, it is preferable that the hydraulic inorganic molded article has an average pore diameter of 0.0135 μm or more and 0.0160 μm or less, and a mode pore diameter of 0.0170 μm or more and 0.0250 μm or less.

Further, as set forth in claim 2, the hydraulic inorganic raw material includes 100 parts by weight of hydraulic inorganic powder, 50 to 70 parts by weight of siliceous inorganic fine powder, and beaten cellulose fiber in total solid content. The slurry preferably contains 1% by weight to 10% by weight and water and has a total solid content of 20% by weight to 50% by weight.

That is, if too much silica inorganic powder is added, the volume ratio of the silica inorganic powder in the molded article increases, and physical properties such as flexural strength decrease.
As described above, with respect to 100 parts by weight of the hydraulic inorganic powder, 5
The addition amount is preferably from 0 to 70 parts by weight.

If the amount of the beaten cellulose fiber is too small, the trapping property of the powder raw material such as hydraulic inorganic powder and silica inorganic fine powder is deteriorated, and the powder raw material flows out. Since there is a possibility that a problem may occur in the nonflammability performance as a building material, the addition amount is preferably 1% by weight or more and 10% by weight or less in the total solid content as described above.

The hydraulic inorganic powder is not particularly restricted but includes, for example, Portland cement, alumina cement, lime and the like. Examples of the siliceous inorganic fine powder include, but are not particularly limited to, silica sand, silica powder, slag, fly ash, silica fume, and the like containing SiO ₂ as a main component. Among them, the SiO ₂ content is 95% or more. it is preferable to use the silica powder, more specific surface area of 8000 cm ² / g or more 10000 cm ² /
g or less of fine powder is preferred.

The beaten cellulose fiber is obtained by beating fibers of pulp, hemp and the like, and is particularly limited as long as it has a trapping property of the powdery hydraulic inorganic powder and the siliceous inorganic fine powder. However, in consideration of sufficient trapping performance, the fiber length is preferably 1 mm or more and 6 mm or less, and the freeness value (usually about 700 ml) is preferably 300 ml or less.

That is, if the fiber length is less than 1 mm, the ability of the powder material to be trapped in the slurry is poor, and the powder material may flow out, which may cause problems in molding. May be entangled with each other, causing a problem in appearance or physical properties.

On the other hand, if the freeness value exceeds 300 ml, the ability to capture the powdery raw material in the slurry becomes poor, and the powdery raw material may flow out, causing a problem in molding.

[0015] The hydraulic inorganic raw material may be a polyvinyl alcohol-based synthetic fiber having heat resistance as described in claim 3 (hereinafter referred to as "heat-resistant PVA fiber").
Or 0.1% by weight or more and 2.0% by weight or less in the total solid content, or 0.1% by weight or more and 2.0% by weight of the carbon fiber in the total solid content as described in claim 4. % Is more preferable.

The heat-resistant PVA fiber refers to a 160-degree autoclave cured by a solvent wet cooling gel spinning method.
It is a PVA fiber that can withstand heat of not less than ℃ and has higher heat resistance than before. If the amount of the heat-resistant PVA fiber is too small, the reinforcing effect of the fiber is lost, and if the amount is too large, the fluidity of the material is hindered and a molding problem may occur. It is preferable that the addition amount is 0.1% by weight or more and 2.0% by weight or less.

The length of the heat-resistant PVA fiber is not particularly limited, but is preferably 2 mm or more and 8 mm or less. That is, if the fiber length is less than 2 mm, the reinforcing effect is lost,
If it exceeds 8 mm, the fibers may be entangled with each other, which may cause problems in appearance or physical properties.

As the carbon fiber, it is preferable to use a fiber which is not firmly converged as a single fiber of several microns is converged by using a sizing agent such as an epoxy resin, but is gently converged by water. If the amount of the carbon fiber is too small, the reinforcing effect of the fiber is lost, and if the amount is too large, the fluidity of the material may be impaired and a molding problem may occur. It is preferable to set the addition amount to not less than 2.0% by weight and not more than 2.0% by weight.

The length of the carbon fiber is not particularly limited, but is preferably 2 mm or more and 8 mm or less. That is, when the fiber length is less than 2 mm, the reinforcing effect is lost, and when the fiber length is more than 8 mm, the fibers may be entangled with each other to cause a problem in appearance or physical properties. In addition, in addition to the above, a scaly inorganic mineral for preventing shrinkage (for example, mica or the like) or a needle-like inorganic mineral for reinforcement (for example, wollastonite) is added to the hydraulic inorganic material in addition to the above. be able to. The amount of the flaky inorganic mineral or the reinforcing needle-like inorganic mineral is preferably 10% by weight or less based on the total solid content.

On the other hand, the method for producing a hydraulic inorganic molded article according to the present invention comprises the steps of: providing a hydraulic inorganic powder and silica on a water-permeable sheet moving from one side to the other side along the suction surface of the suction means. While developing the hydraulic inorganic raw material supplied by the roll from above while supplying the hydraulic inorganic raw material including the porous inorganic fine powder and the beaten cellulose fiber, while shaping into the space shape between the water-permeable sheet and the roll, After obtaining a formed body through a step of squeezing excess water in the hydraulic inorganic raw material by the suction means through a permeable sheet, the obtained formed body is steam-cured, and further, is autoclaved. .

In the structure of the production method of the present invention, the hydraulic inorganic raw material is not particularly limited, but first, beating cellulose fibers and water are charged into a defibrating machine to defibrate, and if necessary, the beating cellulose fibers are crushed. And water are put into a defibrating machine and defibrated, and then a heat-resistant PVA fiber or a carbon fiber is added and mixed in the first mixing step, and the mixture mixed in the first mixing step is mixed with a hydraulic inorganic powder and It is preferable to prepare through two steps of a second mixing step of adding and mixing the siliceous inorganic fine powder.

When carbon fibers are used, it is preferable not to perform excessive mixing in the first mixing step. That is, if excessive mixing is performed, the carbon fibers may be entangled with each other to form fiber balls or the like, and the dispersibility may be deteriorated. On the other hand, it is preferable not to perform excessive mixing in the second step. That is, the solid matter in the slurry is reduced to 20
It is preferable that the dispersion be made to be not less than 50% by weight and not more than 50% by weight so that the dispersion of the carbon fibers is promoted by the viscosity of the slurry.

When an omni mixer is used, the mixing time in the first mixing step is preferably 15 seconds or more and 30 seconds or less when the rotation speed of the omni mixer is 300 rpm. The mixing time in the second mixing step is preferably 10 minutes or more and 20 minutes or less when the rotation speed of the omni mixer is 300 rpm.

The water-permeable sheet is not particularly limited, but is preferably formed of felt, nonwoven fabric, or the like, and is preferably in the form of an endless belt. The water-permeable sheet is not particularly limited as long as it has a shape along the suction surface of the suction means at a portion where the raw material is supplied, but may be formed in advance in a shape along the suction surface of the suction means.

Although the suction means is not particularly limited,
It is preferable to connect the suction box endlessly via a chain or the like so that the suction box moves at the same speed as the water-permeable sheet. The developing roll may be provided only on the side of the raw material supply device in the traveling direction of the water-permeable sheet. Is preferred.

Further, it is preferable to provide a pressure roll behind the developing roll to press the shaped product developed and formed by the developing roll from above. That is, with the developing roll alone, roping or the like may occur on the surface of the shaped object, and the outer shape may be deteriorated.

The developed article can be pressed by a die which has been cut or marked or decorated as necessary. Cutting can be performed either before or after pressing. The obtained shaped article may be cut as necessary before curing and curing, and then may be pressed with a mold to apply marking or decoration to the surface.

In the pressing step, the lower the surface pressure, the lower the specific gravity can be obtained. However, in order to exhibit predetermined performance such as marking and decoration, it is preferably 20 kg / cm ² or more, and preferably 40 kg / cm ² or more.
Around ² is more preferable.

In the steam curing and the autoclave curing, the formed form is heated to 40 ° C. to 80 ° C.
After steam curing for 3 hours to 10 hours (preferably 5 hours to 7 hours) in a steam atmosphere of not more than (preferably 50 ° C. to 60 ° C.), 160 ° C. to 180 ° C.
It is preferable to perform autoclave curing in the following autoclave for 6 to 24 hours.

The molded body thus obtained can be coated as required.

[0031]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below.
The details will be described with reference to the drawings. FIG. 1 shows an example of an apparatus for producing a formed body used for producing a hydraulic inorganic molded article according to the present invention.

As shown in FIG. 1, this manufacturing apparatus 1 comprises a water permeable sheet 2, a raw material supply device 3, a suction means 4
And a pressure roll 11. Water permeable sheet 2
Has an endless belt shape and has a water permeability, and rotates at a constant speed in the direction of arrow A in FIG. 1 via a drive roll 21 and a number of guide rolls 22.

The suction means 4 includes a decompression box 5 and a number of suction boxes 6.

A number of suction boxes 6 are connected in an endless belt shape via an annular chain (not shown), and the sprocket 6 on which the chain is hung is connected.
1 and 61 are rotated at the same speed in the same rotational direction as the water-permeable sheet 2 by rotating, and when they become parallel to the upper parallel portion of the water-permeable sheet 2, each suction box 6 The suction surface, which is the upper surface, is in close contact with the lower surface of the water-permeable sheet 2.

Although not shown, the suction box 6 has a flat suction surface, and a large number of water absorption holes are formed in the suction surface.

The decompression box 5 is connected to decompression means such as a vacuum pump and a blower, has a decompression hole (not shown) on its upper surface, and receives the suction box 6 from below. ing. Then, a hole (not shown) provided at the bottom of the suction box 6 moved onto the pressure reducing box 5 by the rotation drive of the sprocket 61 coincides with the pressure reducing hole, and the inside of the suction box 6 passes through the hole and the pressure reducing hole. Is decompressed so that excess water in the raw material can be squeezed out through the water-permeable sheet 2 from the water absorption hole.

The raw material supply device 3 includes a raw material box 31 and a cylindrical developing roll 32. The raw material supply device 3 is disposed on the base end of the decompression box 5 and supplied to the raw material pox 31 from a diaphragm pump (not shown). The hydraulic inorganic raw material 7 is supplied onto the water-permeable sheet 2 from the lower end of the raw material box 31,
The raw material pox 31 is developed to a predetermined thickness by a developing roll 32 provided on the side of the water-permeable sheet 2 in the traveling direction.

The pressure roll 11 presses and shapes the dewatered expanded shape 7a, and removes roping or the like generated on the surface of the expanded shape 7a by the expansion roll 32.

Next, an example of a method for producing a hydraulic inorganic molded article using the apparatus 1 for producing a molded article will be described in detail.

In this production method, first, 100 parts by weight of the hydraulic inorganic powder, 50 to 70 parts by weight of the siliceous inorganic fine powder, and 0.1% of the beaten cellulose fiber in the total solid content.
A hydraulic inorganic raw material 7 containing 1% by weight or more and 10% by weight or less and containing heat-resistant PVA fiber or carbon fiber as needed in an amount of 0.1% by weight or more and 2.0% by weight or less in the total solid content is prepared.

Then, the water permeable sheet 2 and the suction box 6 are rotated in the same direction and at the same speed, and the inside of the pressure reducing box 5 is reduced to 350 mmHg or more by pressure reducing means.
While maintaining the pressure reduced to 0 mmHg or less, the hydraulic inorganic raw material 7 is supplied to the raw material box 31 of the raw material supply device 3 by the diaphragm pump, and a predetermined amount of the hydraulic inorganic raw material is supplied onto the permeable sheet 2 from the lower part of the raw material box 31. 7 is supplied.

Next, the hydraulic inorganic raw material 7 is developed and formed into a flat shape by the developing rolls 32 into the space formed by the suction surface of the suction box 6 and the developing rolls 32 over the water-permeable sheet 2. . Then, after the excess water in the developed and shaped object 7a is dehydrated under reduced pressure by the suction means 4, it is further pressed by a pressure roll 11 to adjust the surface state and roping or the like is removed to obtain a long formed body 7b.

Next, the obtained elongated shaped body 7b is cut into cut pieces of desired dimensions by a cutting device (not shown), and the cut pieces are pressed by a press device to transfer the pattern of the mold. Obtained formed form. Although not shown, the formed form is steam-cured for 3 hours to 10 hours in a steam atmosphere of 40 ° C to 80 ° C,
Autoclave curing is performed in an autoclave at 160 ° C. to 180 ° C. for 6 hours to 24 hours to obtain a hydraulic inorganic molded article.

The hydraulic inorganic molded body obtained in this manner is characterized in that the hydraulic inorganic raw material is a very fine powder and has a high reactivity and the Si (silicon) content in the silica inorganic fine powder and the hydraulic inorganic powder in the hydraulic inorganic powder. The Ca (calcium) component is hydrothermally synthesized by autoclaving to produce tobermorite, a stable cement hydrate, and the molded product has a pore volume of
It has fine pores of 0.300 cc / g or more and 0.390 cc / g or less, and has a specific surface area of 90 m ² / g or more, and is lighter and more excellent in strength than a conventional hydraulic inorganic molded article.

The hydraulic inorganic molded article and the method for producing the same according to the present invention are not limited to the above embodiment. For example, in the above-described embodiment, the generation form 7b is a flat plate, but may be a waveform or an irregular form. Also,
In the above embodiment, the developed and shaped object 7a is continuously shaped, but may be a batch type.

[0046]

Embodiments of the present invention will be described below in more detail.

(Example 1) Each composition was charged into an omni mixer at the following compounding amounts and mixed at a rotation speed of 300 rpm.
A hydraulic inorganic raw material was obtained. [Blend]-100 parts by weight of ordinary Portland cement (manufactured by Chichibu Onoda)-60 parts by weight of finely divided silica (manufactured by Sumitomo Osaka Cement)-10 parts by weight of beaten pulp (manufactured by Paltec Co., Ltd., cello fiber)-water 450 Parts by weight

Then, using the manufacturing apparatus 1 shown in FIG.
After continuously shaping the shaped product, the shaped product was cut by a cutter device, transferred to a press device, and compression-molded at a surface pressure of 40 kg / cm ² to obtain a formed product. This green compact was steam-cured for 6 hours in a saturated vapor pressure atmosphere at 50 ° C., further transferred to an autoclave and autoclave-cured at 180 ° C. for 8 hours to obtain a hydraulic inorganic molded article.

Example 2 A hydraulic inorganic molded article was obtained in the same manner as in Example 1 except that the composition was cured in an autoclave for 24 hours. (Example 3) Same as Example 1 except that a heat-resistant PVA fiber (Kuraray K-II, trade name) was added to the blend of Example 1 so as to be 1% by weight of the total solid content. Thus, a hydraulic inorganic molded article was obtained.

(Example 4) Carbon fiber (manufactured by Toho Rayon Co., Ltd.) was added to the composition of Example 1 so as to be 1% by weight of the total solid content.
A hydraulic inorganic molded article was obtained in the same manner as in Example 1 except that trade name: Vesfite HTA-C6) was added.

(Comparative Example 1) A hydraulic inorganic molded article was obtained in the same manner as in Example 1 except that the autoclave was cured for 4 hours. (Comparative Example 2) A hydraulic inorganic molded article was obtained in the same manner as in Example 1 except that the surface pressure during pressing was set to 100 kg / cm ² .

The hydraulic inorganic molded articles obtained in Examples 1 to 4 and Comparative Examples 1 and 2 and a commercially available flat tile manufactured by a dry roll press method as Comparative Example 3 (trade name of Kubota Corporation) Porosity, specific surface area, and the like of a commercially available wagtail (New Wave II manufactured by Matsushita Electric Works, Ltd.) manufactured by Hatschek method as Comparative Example 4.
The specific gravity and bending strength were measured, and the results are shown in Table 1.

The porosity and specific surface area were measured by a mercury intrusion method using Autopore 9220 manufactured by Shimadzu Corporation. The specific gravity was measured by an underwater suspension method according to JIS A 5430 (1). The bending strength is JIS A14
08 was measured by a three-point bending test method.

[0054]

[Table 1]

As shown in Table 1, the hydraulic inorganic molded article of the present invention is:
It can be clearly understood that both are lightweight and excellent in strength.

[0056]

The hydraulic inorganic molded article according to the present invention comprises:
With the above configuration, the porosity is large, the weight is light, and the strength is excellent.

Therefore, the workability is improved and
When used as a roofing material for a building, the weight of the entire roof can be reduced, and a building excellent in strength against an earthquake or the like can be constructed. Further, when a heat-resistant PVA fiber or a carbon fiber is added as a reinforcing fiber as in the third and fourth aspects, the strength is further improved.

Since the method for producing a hydraulic inorganic molded article according to the present invention is constituted as described above, a steam hydraulic inorganic molded article can be produced stably. Also,
According to the sixth aspect, it is possible to obtain a hydraulic inorganic molded article which is lighter and more excellent in strength.

[Brief description of the drawings]

FIG. 1 is an explanatory view of one example of an apparatus for producing a formed body used for producing a hydraulic inorganic molded article of the present invention.

[Explanation of symbols]

 2 Water permeable sheet 3 Raw material supply device 32 Developing roll 4 Suction means 7 Hydraulic inorganic raw material 7a Developed and shaped material 7b

Claims (6)

[Claims] 1. A hydraulic inorganic material containing a hydraulic inorganic powder, a siliceous inorganic fine powder and a beaten cellulose fiber is molded and cured, and has a porosity of 0.300 cc / g or more and 0.390 cc / g.
A hydraulic inorganic molded article having the following pores and a specific surface area of 90 m ² / g or more. 2. The hydraulic inorganic raw material comprises 100 parts by weight of hydraulic inorganic powder and 50 parts by weight or more of silica inorganic fine powder.
0 parts by weight or less, containing beaten cellulose fiber in an amount of 1% by weight to 10% by weight in total solids and water;
2. The hydraulic inorganic molded article according to claim 1, which is in the form of a slurry of not less than 50% by weight and not more than 50% by weight. 3. A hydraulic inorganic raw material comprising polyvinyl alcohol-based synthetic fiber having heat resistance of 0.1% by weight based on the total solid content.
3. The hydraulic inorganic molded article according to claim 2, comprising at least 2.0% by weight or less. 4. The hydraulic inorganic molded product according to claim 2, wherein the hydraulic inorganic raw material contains carbon fibers in an amount of 0.1% by weight or more and 2.0% by weight or less based on the total solid content. 5. A water permeable sheet moving from one side to the other side along the suction surface of the suction means,
The space between the water-permeable sheet and the roll while developing the hydraulic inorganic raw material supplied by the roll from above while supplying the hydraulic inorganic raw material including the hydraulic inorganic powder, the siliceous inorganic fine powder and the beaten cellulose fiber Along with shaping into a shape, after obtaining a formed form through a step of squeezing excess water in the hydraulic inorganic raw material by the suction means over a permeable sheet, steam-curing the obtained formed form, And a method for producing a hydraulic inorganic molded article to be autoclaved. 6. The molded body is steam-cured for 3 hours to 10 hours in a steam atmosphere of 40 ° C. to 80 ° C., and
The method for producing a hydraulic inorganic molded article according to claim 5, wherein the autoclave is cured in an autoclave at 160 ° C to 180 ° C for 6 hours to 24 hours.