JPH0415338B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a humidity control panel with excellent moisture absorption performance.

(Prior Art) Wood materials, xonotlite-based calcium silicate boards, or paperboard impregnated with hygroscopic fillers have been known as materials for absorbing steam (humidity) in rooms and storage rooms.

(Problems to be Solved by the Invention) However, all of the above conventional materials take in moisture from the air and retain it as adsorbed water within the material, and cannot be used in environments where water vapor is constantly generated or in high humidity conditions. In an atmosphere for a long period of time, once the moisture absorption saturation point of the material is reached, no more water can be taken in as adsorbed water, resulting in insufficient moisture control performance.

Therefore, in order to improve this moisture control property, the inventors of the present invention, as a preliminary step to the present invention, created conditions for the low moisture absorption material to retain water and continue its moisture absorption effect by combining a high moisture absorption material and a low moisture absorption material. However, there was a problem in that the hygroscopic filler was transferred to a low hygroscopic material, making it impossible to maintain hygroscopicity over a long period of time.

(Object of the Invention) In view of the above, the present invention has been made to further improve the above-proposed composite panel, and includes a plate body containing a hygroscopic filler and a porous body having specific voids. By providing a moisture-permeable layer in which moisture does not transfer substantially between the layers, it is possible to take in more moisture than can be retained as adsorbed water, and it is possible to maintain humidity control even in times of high humidity.
The purpose is to prevent the hygroscopic filler from flowing out and maintain its hygroscopicity over a long period of time.

(Means for solving the problem) In order to achieve this object, the solution taken by the present invention consists of a plate body having a hygroscopic filler internally retained in the voids, and a fine pore size having an average pore size of 10μ or less. It has a structure in which a porous material having voids is integrated with a moisture permeable layer through which moisture does not substantially move.

(Function) When a panel constructed according to the present invention with the above-mentioned configuration was allowed to absorb moisture from the plate side formed by internally retaining a hygroscopic filler in the voids at a constant temperature, the following phenomenon occurred.

The weight of the porous body on the back side was more than that which could be saturated by itself.

The super moisture absorbent material (plate) on the surface side showed almost no weight increase at the initial stage of moisture absorption.

When it further absorbed moisture, water dripped from the porous material on the back side.

There was no hygroscopic filler mixed in the dropped water.

Due to the above phenomenon, free water was generated in the porous body on the back side.

The mechanism by which this free water is generated is not clear, but it is speculated that moisture exists in a state close to saturated steam in the microscopic voids in the porous material on the back side, while a hygroscopic filler is internally retained within the voids. Since the plate has residual moisture absorption capacity, a small difference in vapor pressure and temperature occurs between the two, and in the microscopic voids with a pore diameter of 10 μm or less, the material liquefies due to cohesive force and is retained as free water.

Furthermore, if the material is left under high humidity, moisture that cannot be retained within the porous body will drip out of the material.

Moreover, since they are integrated through a moisture-permeable layer through which virtually no moisture moves, moisture in the porous body does not come into contact with the hygroscopic filler in the plate, and the hygroscopic filler transfers into the porous body. There is nothing to do.

(Example) Examples of the present invention will be described below with reference to the drawings.

FIG. 1 shows a cross-sectional structure of a humidity control panel A according to an embodiment of the present invention. A porous body 2 having the following fine voids is integrated with a moisture permeable layer 3 in which water does not substantially move.

The hygroscopic filler contained in the upper air plate 1 includes calcium chloride, magnesium chloride, lithium chloride, sodium silicate, sodium polyacrylate, PVA, deliquescent compounds such as triethylene glycol, and water-soluble polymers. It is preferable to use either a single substance or a mixture thereof, since they can be easily retained internally by impregnation or dispersion kneading. Further, as other hygroscopic fillers, sepiolite, zeolite, grafted starch, isobutylene maleic anhydride, polyacrylate, etc. made insoluble by crosslinking may be used.
In this case, the plate 1 may be any material as long as it can hold the hygroscopic filler in a minute void and the inside communicates with the outside air, and may be one formed by kneading the filler during manufacturing or forming it into a plate shape. It is made by impregnating the water with an aqueous solution of upper air filler and drying it.
Specifically, (a) impregnation into porous boards such as calcium silicate boards, (b) mixing with paper, cloth or inorganic fibers such as wood fibers and rock wool, and (c) mixing with hydraulic substances such as cement and gypsum. It can be obtained by kneading and curing, or by kneading with (d)olefin resin etc. and foaming and curing.

Further, the size of the microscopic voids in the porous body 2 varies depending on the material and even within the same material, but the size is such that vapor near the saturation point in the microscopic voids condenses with a small amount of energy. It has been demonstrated that the average pore size is less than 10μ. In addition, the porous body 2 is preferably one that has little strength loss or deformation in a water-retaining state, and specifically, mullite, brick, ceramic sintered body such as unglazed tile, porous glass, or one that has open cells of 10μ or less. There are porous resin bodies, gypsum hardened bodies, cement-based hardened bodies, etc. On the other hand, wood fiberboard, inorganic fiberboard, paper, felt sheets, etc. have good capillary action.
Porous materials with voids of 20μ or more are unsuitable because they do not generate condensed water.

In addition, the moisture permeable layer 3 to which water does not substantially move is a layer provided so that the water generated within the porous body 2 does not come into contact with the hygroscopic filler, and depending on the type of hygroscopic filler, the moisture permeable water repellent layer , a semipermeable membrane, an ultrafiltration membrane, a mesh sheet, and a perforated resin sheet. In other words, if the hygroscopic filler is a deliquescent substance, migration due to ions will occur, so it may be transferred through a reverse osmosis membrane such as acetyl cellulose, an ultrafiltration membrane such as polyacrylonitrile, or through a porous membrane such as a reticulated sheet or a porous resin sheet. It is preferable to have a gap between the mass body 2 and the plate body 1, or to coat the porous body 2 or the plate body 1 with silicone or fluorine resin, since this does not impede moisture permeability. On the other hand, if the moisture-absorbing filler is a water-soluble polymer or an insoluble polymer, water-repellent membranes, perforated sheets, etc.
It is effective as long as it prevents the plate 1 from getting wet. In short, there is virtually no movement of water, and the water content is 1×10 ^-3 g/m・
Any material having a moisture permeability of hr/mmHg or higher is sufficient.

(Experimental Example) Next, as a humidity control panel according to a specific example of the present invention, (a) 20 parts by weight of calcium chloride as a hygroscopic filler, 100 parts by weight each of gypsum and water were added to the back side of a plate which was kneaded and hardened. (Example 1) B Example 1 In place of the hygroscopic filler, 20 parts by weight of triethylene glycol was used, and in place of the porous material, a xonotrite calcium silicate plate (average pore diameter 0.3μ) was laminated and integrated (Example 2) One that did not form a silicone coating film (Comparative Example 1) D. Instead of the porous material of Comparative Example 1, a resin-based porous sheet (average pore diameter 20μ) used in felt pens with good capillary action was laminated. (Comparative Example 2) (Comparative Example 3) In place of the porous material of Example 1, filter paper (average pore diameter 16 μm) was laminated and integrated (Comparative Example 3). In addition, the plates of each layer used in Example 1 above, the zonolite calcium silicate plate used in Example 2, and the resin porous sheet and filter paper used in Comparative Examples 2 and 3 were each equilibrated in a desiccator at 95% RH in advance. When the moisture content was measured when the moisture content was measured until reaching the moisture content, the moisture content of the board with the hygroscopic filler added in Example 1 was 70%, that of the porous body made of hardened plaster was 5%, and the moisture content of the board with the hygroscopic filler of Example 1 was 5%. Itakyu with a hygroscopic filler internally added has a value of 70%, xonotlite calcium silicate board has a value of 25%, the resin porous sheets of Comparative Examples 2 and 3 have a value of 0%, and filter paper has a value of 20%. Ta.

Therefore, as a first experiment, 30
After controlling the humidity at 95% RH, they were laminated and integrated, the four sides and back of each were airtightly sealed, and the moisture content of each was measured after being left in an atmosphere of 95% RH for 7 days. As a result, the moisture content of the porous plate obtained by hardening the plaster on the back side in Example 1 increased by 15%, and the moisture content of the xonotlite calcium silicate plate on the back side in Example 2 increased by 30%. The resin-based porous sheet and filter paper in Comparative Examples 2 and 3 showed no increase in moisture, with 0% and 5%, respectively. From this, it became clear that the generation of free water in Examples was not due to the movement of water due to capillary action due to contact.

Next, as a second experiment, the panels of Example 1 and Comparative Example 1 in the first experiment were left open for another 14 days in an atmosphere of 25°C and 95% RH to continue absorbing moisture. Moisture began to drip from the back layer of each. In this case, calcium chloride, which is a hygroscopic filler, was not present in the dropped water in Example 1, but it was found to exist in the water droplets of Comparative Example 1 in an ionic state. Therefore, it is judged that in Comparative Example 1, the hygroscopicity gradually decreases.

(Effects of the Invention) As explained above, according to the humidity control panel of the present invention, a plate body having high hygroscopicity and a porous body having micro voids of 10μ or less are combined by retaining a hygroscopic filler internally. By doing this, more water than the porous body can hold on its own can be taken into the interior as free water, and even if it is placed in an atmosphere where water vapor is constantly generated, the porous body will not be able to absorb water due to gravity or power. Moisture can be drained from the body to the outside of the panel, allowing it to continue absorbing moisture. Moreover, even if the hygroscopic filler is water-soluble or deliquescent, the intervening moisture permeable layer can prevent it from migrating to the porous body and maintain its hygroscopic ability over a long period of time.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a panel according to an embodiment of the present invention. 1... Plate body, 2... Porous body, 3... Moisture permeable layer.

Claims (1)

[Scope of Claims] 1. A plate formed by internally retaining a hygroscopic filler in the voids and a porous material having microscopic voids with an average pore diameter of 10μ or less form a moisture permeable layer in which water does not substantially migrate. Humidity control panel integrated through. 2 The moisture permeable layer is a moisture permeable water repellent membrane, a semipermeable membrane, a reverse osmosis membrane,
Claim 1 consisting of one selected from an ultrafiltration membrane, a reticulated sheet body, and a perforated resin sheet body
Humidity control panel as described in section.