JPH0633629B2 - Hygroscopic composite material - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a composite material having excellent hygroscopicity suitable for use as an interior panel material for buildings, other wall materials, or a single hygroscopic member. is there.

(Prior Art) Conventionally, as a material that absorbs moisture in a room or a warehouse,
Wood, zonolite-based calcium silicate board, or hygroscopic filler-impregnated paper is known.

(Problems to be Solved by the Invention) However, in any of the above materials, when moisture in the air is taken in as adsorbed water and saturation is reached, further moisture cannot be absorbed, so that the humidity control function is unsatisfactory. In addition to being sufficient, there is a problem that dehumidification requires time and energy.

The present invention has been made in view of such a problem, and absorbs moisture to generate free water in the material to enhance the hygroscopic capacity and drain the free water, thereby maintaining the hygroscopicity for a long time. It is intended to provide a hygroscopic composite material that can be processed.

(Means for Solving Problems) In order to achieve the above object, the hygroscopic composite material of the present invention is
A hygroscopic filler is internally added to the voids, and a hygroscopic body formed by holding the hygroscopic filler is integrated with a porous body having innumerable fine pores, whereby free water is generated in the porous body and perforated in the porous body. It is characterized in that the generated free water is discharged to the outside of the material through a drain hole that communicates with the outside.

(Operation) When the hygroscopic composite material configured as described above is made to absorb moisture from the hygroscopic body side at a constant temperature, the following phenomenon occurs.

(a). The water content on the side of the porous body becomes higher than the saturated water content of the porous body alone (a state in which water has absorbed and reached equilibrium) due to the generation of free water.

(b). While the water content on the porous body side may increase, the water content on the hygroscopic body side may not increase, and the absorbed moisture is transferred to the porous body.

(c). If moisture absorption is performed for a long period of time, water will drip through the drain holes of the porous body.

Due to the above phenomenon, the moisture in the air absorbed in the hygroscopic body is transferred to the porous body and is changed into water in the porous body.

The mechanism by which this free water is generated is not clear, but since the porous body has a low equilibrium water content and cannot fully absorb moisture in the micropores under high humidity, moisture near saturated vapor exists while moisture absorption The body has a high equilibrium water content and has a residual moisture absorption capacity even if it is exposed to high humidity unless the hygroscopic filler absorbs moisture completely.Therefore, a minute vapor pressure difference and temperature difference between the two are integrated near the interface. It is considered that water is generated by aggregating on the side of the porous body which is close to saturation and is generated.

In such a state, when the diameter of the micropores of the porous body is about 10 μm or less, particularly 3 μm or less, liquefaction is promoted by the cohesive force,
It has been confirmed by experiments that a larger size, for example, a paper filter (average pore size: 20μ), has a small cohesive force, and moisture is less likely to form water droplets, resulting in a smaller moisture absorption effect.

Since there is a change in temperature during actual use, the condensation of moisture in the porous body further increases when the temperature decreases, and water retention is promoted in the porous body.

When the above composite material absorbs moisture under higher humidity, a large amount of free water is generated, and the water is dropped to the outside through the drain holes provided in this porous body.

Positively sucking from the drainage hole using an appropriate suction means promotes recovery of water.

(Embodiment) An embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a perspective view of a hygroscopic composite material formed in a panel shape, and (1) is a flat-shaped hygroscopic body. Similarly, a flat plate-shaped porous body (2) is integrally fixed to one surface of (1). (3) is a plurality of drainage holes provided between the upper and lower end surfaces of the porous body (2).

The hygroscopic body (1) is calcium chloride as a hygroscopic filler,
Deliquescent substances such as magnesium chloride and lithium chloride, or triethylene glycol, sodium polyacrylate, P
One or more of water-soluble polymers such as VA and inorganic moisture absorbents such as sodium silicate, sepiolite and xonotlite, water-insoluble polymer moisture absorbents such as grafted starch, isobutylene maleic anhydride and polyacrylic acid salts A mixture of two or more kinds is used, and this hygroscopic filler is internally added and held in a base material having a large number of voids communicating with the outside air.

Specifically, cement, one obtained by kneading and integrating a hydraulic substance such as gypsum and the above hygroscopic filler with water and curing, or calcium silicate plate or paper, one impregnated with a hygroscopic filler in cloth, It is obtained by adding a hygroscopic filler to wood fiber, rock wool fiber, etc., and by kneading the hygroscopic filler with an olefin resin or the like to foam.

On the other hand, in the porous body (2), there are variations in the size of innumerable fine pores inside depending on the material or even with the same material, but the porous body (2) penetrates and is retained in these fine pores from the moisture absorbent body (1) side. It is necessary that the moisture, which has become almost saturated, has fine pores with a size that allows it to condense with a small energy difference. It is desirable that the average pore size is about 10 μm or less, preferably 3 μm or less.

As the porous body having such fine pores (2), specifically, gypsum hardened body, cement hardened body, calcium silicate hardened body, mullite, brick, inorganic sintered body such as unglazed tile, etc. However, other porous resin bodies or glass foams may be used as long as the fine pores have the above-mentioned pore size or less. Further, when the deterioration of strength or warpage due to water absorption has an adverse effect, among the above-mentioned materials, a cement hardened body, a calcium silicate hardened body or the like having good water resistance is preferable.

However, wood fiber board, inorganic fiber board, paper, a material such as felt sheet made of a material having voids with a good average pore diameter of 20 μm or more due to capillary phenomenon,
The generation of condensed water is reduced, which is inappropriate.

The bonding surface between the hygroscopic body (1) and the porous body (2) has an adhesive layer that does not impair the moisture permeability, or a water-repellent layer or semi-permeable membrane that does not allow the hygroscopic filler or water to move. You may intervene.

Also, such as a decorative panel such as paper, cloth, or a moisture permeable coating film, plywood, gypsum board, rock wool sound absorbing board, etc. on the surface side of the hygroscopic body (1) on which the porous body (2) is not arranged. A moisture-permeable material may be integrally laminated, and a moisture barrier layer may be provided on the exposed surface side of the porous body (2) so as not to absorb moisture from the exposed surface.

FIGS. 2 and 3 show different forms of the hygroscopic composite material. FIG. 2 shows the flat plate-shaped porous body (2) as the center and the flat plate-shaped porous body (1) on both sides thereof. (1) is joined and integrated in a sandwich shape. Fig. 3 shows that a cylindrical moisture absorbent (1) is filled and integrated in the central hole of a porous body (2) formed in a thick cylindrical shape. It will be.

The porous body (2) should be provided with drain holes (3) (3) ... (3) of appropriate diameter that communicate with each other in the vertical direction parallel to the joint surface with the hygroscopic body (1). Is the same as in the above embodiment.

The moisture-absorbing composite material having such a structure can be used alone as a dehumidifying device by depressurizing the drainage hole (3) to dehydrate it. The structure of the moisture-absorbing composite material is not limited to the above-mentioned embodiment, and needless to say, various structures may be used.

Next, specific examples and comparative examples of the present invention will be shown.

Example 1 Moisture absorption obtained by using triethylene glycol as a hygroscopic filler, adding 20 parts by weight of triethylene glycol to each of 100 parts by weight of gypsum and kneading, then forming into a flat plate and curing. Apply 100 gypsum and water to one side of the body.
: A structure in which a porous body (average pore size of micropores in the substantial part 2.3 μ) formed by mixing and kneading at a ratio of 50 and then molding and curing so as to provide a plurality of drainage holes penetrating between the upper and lower end surfaces is laminated and integrated. A moisture-absorbent composite material was obtained.

Example 2 In place of the porous body of Example 1, an extrusion-molded cement calcium silicate plate (average pore size of fine pores: 0.6 μ) was used in Example 1 above.
The moisture absorbent composite was formed by laminating and integrating with the moisture absorbent.

Comparative Example 1 Instead of the porous body of Example 1, paper (average fine pore diameter)
20 μ) was laminated and integrated on a hygroscopic body to form a hygroscopic composite material.

In Examples 1 and 2 and Comparative Example above, the moisture content of the porous body and the simple substance of the hygroscopic material constituting the hygroscopic composite material when preliminarily adsorbing moisture until reaching equilibrium in a desiccator of 95% RH is as follows. Met.

Hygroscopic material: 70%, gypsum hardened material: 5%, extruded cement calcium silicate board: 13%, paper filter: 20%.

In addition, each of the porous bodies and the moisture absorbents of Examples 1 and 2 and the comparative example were preliminarily conditioned at 35% RH, and then each moisture absorbent composite material was formed as described above. After moisture absorption for a day, the moisture content of each porous moisture absorbent and moisture absorbent of these moisture absorbent composite materials was measured, and the results were as follows.

Hygroscopic material: 20-25%, gypsum hardened material: 15%, extruded cement calcium silicate board: 20%, paper filter: 5%.

From the above results, it can be understood that the porous bodies in Examples 1 and 2 have a weight increase of not less than the saturated moisture content, and the free water is generated in the porous bodies correspondingly.

On the other hand, it was confirmed that even in the case of a paper filter having a good water absorption property due to a capillary phenomenon, the water content from the hygroscopic body to the paper filter is small due to its small water content.

Further, the moisture-absorbing composite materials of Examples 1 and 2 and Comparative Example were continuously added.
When moisture was absorbed for 14 days, moisture was dropped from the drain holes provided in the porous bodies in the moisture absorbent composites of Examples 1 and 2, but no moisture was dropped in the moisture absorbent composites of Comparative Examples. .

(Effects of the Invention) As described above, according to the moisture-absorbing composite material of the present invention, the hygroscopic filler is internally added to and held in the voids of the base material, and the porous body having innumerable fine pores is provided. Due to the integration, the porous body has a structure capable of taking in more water than free moisture as free water, improving the hygroscopicity and free water of the porous body being unidirectionally directed to the porous body. Since water is discharged to the outside from the drain holes provided in communication with each other, the time and energy required for dehydration can be small, and continuous moisture absorption from the hygroscopic body side can be made possible.

Therefore, it is possible to maintain the hygroscopicity for a long period of time and to exert a desired humidity control function, and further, in an atmosphere where a large amount of moisture is constantly generated, the drainage provided in the porous body by the positive suction force is always provided. By removing water from the holes, moisture can be quickly removed, and it can be effectively used not only as a wall material for buildings but also as a single dehumidifying device.

[Brief description of drawings]

The drawings show three embodiments of the present invention. FIG. 1 is a perspective view of Example 1, FIG. 2 is a perspective view of Example 2, and FIG. 3 is a perspective view of Example 3. (1) …… Hygroscopic material, (2) …… Porous material, 3. Drainage hole.

Claims (1)

[Claims] 1. A drainage hole is formed in a porous body having innumerable fine pores having an average pore diameter of about 10 μm or less, such as a hardened cement body, a hardened gypsum body, a hardened silica body, and an inorganic sintered body.
A hygroscopic composite material, wherein a hygroscopic material obtained by internally adding and holding a hygroscopic filler to a base material is integrated with the porous body.