JPH0389915A - Moisture adsorption-desorption material and sheet-like material thereof - Google Patents

Abstract

PURPOSE:To provide reversible moisture-control function by forming a moisture control part out of a mixture of porous adsorbents and polymer adsorbents and reinforcing one side surface of the part with an air-permeable sheet-like material to constitute a moisture adsorption-desorption sheet-like material. CONSTITUTION:A humidity control part is composed of a mixture 2 of porous adsorbents and polymer adsorbents and an air-permeable porous reinforcement sheet-like material 4 is superposed on said part to form a moisture adsorption- desorption sheet-like material 1. And when a layer 3 composed of porous adsorbents is placed on the side of the mixture 2 opposite to the side of the material 4, in addition to the mixture 2 as a moisture control part to form a multilayer moisture control part, moisture controlling effects can be improved. Porous adsorbents are bentonite, zeolite, etc., and polymer adsorbents are denatured starch, cellulose derivatives, polyacrylonitrile derivatives, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a moisture-absorbing and desorbing material and a moisture-absorbing and desorbing sheet material that have excellent humidity control functions.

[Conventional technology] Traditionally, technology has been used to prevent corrosion in buildings, make life more comfortable,
Attempts are being made to provide a particularly suitable humidity environment for sanitation, for preserving the freshness of foodstuffs such as vegetables and fruits, and for preserving clothing, leather goods, crafts, works of art, etc. It has been done.

For example, in houses, there is a problem in that due to humidity, the materials around the building's floors are damaged by rotting fungi and termites, shortening the lifespan of the building and causing discomfort and an unsanitary environment for the residents. As a countermeasure, there have been proposals for moisture-absorbing and desorbing building materials in which zeolite is mixed into a hydraulic composition, but these have the disadvantage that the moisture absorption capacity is small and the effect disappears in a short period of time.

There is also a proposal to install a moisture-proof sheet to block moisture from the soil beneath the floor, but this creates a new problem: moisture is trapped between the ground and the film, and the moisture cannot be removed forever, resulting in higher humidity. It cannot be said that it is a preferable method.

Hydrous amorphous silicon dioxide, calcium oxide, etc. have traditionally been used as desiccants in food products, but the moisture absorption effect ends after a certain period of time, and the moisture absorption ability is affected by the amount of moisture in the atmosphere, such as in the container. There's a problem.

On the other hand, in the case of paintings, sculptures, and other works of art or crafts, strict humidity control is required, as overdrying can cause cracks and high humidity can cause subtle changes in color. Currently, there are no countermeasures that can be taken.

In addition, for clothing and leather products, highly hygroscopic compounds such as calcium chloride and magnesium chloride are sometimes placed in breathable sheets or containers such as paper, but although these products have a dehumidifying effect, Since it has a strong deliquescent property, there is a problem that it becomes muddy or becomes an aqueous solution.

As mentioned above, there are various problems with the current technology, and in various fields, it is possible to easily achieve a humidity control effect for a long time without using large-scale equipment, and to apply it under a wide range of humidity conditions and objects. The reality is that there has been a long-awaited realization of humidity regulating materials and products that can be applied to the environment.

[Problems to be Solved by the Invention] An object of the present invention is to solve such problems and provide a novel moisture-absorbing and desorbing material that provides a suitable humidity environment, and a novel sheet-like material having moisture absorbing and desorbing properties. It is something.

[Means for Solving the Problems] In order to achieve the above-mentioned object, the present invention has the following configuration.

That is, the hygroscopic material of the present invention is a hygroscopic material characterized by being composed of a mixture of a porous adsorbent and a polymer absorbent.

In addition, in the moisture absorbing and desorbing sheet material of the present invention, the moisture regulating section is made of a mixture of a porous adsorbent and a polymer absorber, and one side, both surfaces, or the periphery of the moisture regulating section is reinforced with an air permeable sheet material. This is a moisture-absorbing and desorbing sheet material.

Alternatively, the moisture-absorbing and desorbing sheet-like material of the present invention may include a layer in which the moisture regulating section is made of a mixture of a porous adsorbent and a polymer absorber, and porous holes on the upper side (front side) and/or the lower side (back side) of the layer. A moisture absorbing and desorbing sheet having a multi-layer structure of at least two layers made of a quality adsorbent, wherein one side, both sides, or the periphery of the moisture regulating section is reinforced with an air permeable sheet material. It is a thing.

In the moisture absorbing and desorbing sheet material or moisture absorbing and desorbing sheet material of the present invention described above, the porous adsorbent is preferably activated carbon. The sheet-like material is made of one or more of nonwoven fabric, paper, porous film, woven fabric, and knitted fabric.

Furthermore, the present invention provides a container having moisture absorbing and desorbing properties, which is made entirely or partially using the moisture absorbing and desorbing sheet material of the present invention as described above. It provides:

[Effect] The present invention will be explained in detail below.

The moisture absorbing and desorbing material of the present invention is made of a mixture of a porous adsorbent and a polymer absorber, and when this moisture absorbing and desorbing material is used under high humidity conditions, the porous adsorbent in the humidity adjustment section first absorbs the moisture. Since the material absorbs moisture quickly and the polymeric absorber can store a large amount and a large portion of the moisture, humidity can be reduced quickly and over a long period of time. Conversely, in a dry state, moisture primarily stored in the polymer absorber is quickly released via the porous adsorbent.

Therefore, according to the moisture absorbing and releasing material of the present invention, it is possible to have a humidity regulating function extremely effectively and reversibly, regardless of the amount of moisture or the length of time. In this way, the present invention is completely different in concept and method from the previous proposals using porous adsorbents or polymer absorbers for mere humidity control.

Conventionally, there have been proposals to apply porous adsorbents as humidity control materials, but their moisture absorption capacity is small and their capacity reaches saturation in a short period of time in humid conditions, so their effectiveness cannot be achieved in large-volume areas. I couldn't get it. On the other hand, polymer absorbers have an extremely high ability to absorb moisture, but their rate of absorbing moisture is slow, and once they have absorbed moisture, they have a poor property of releasing it, and their rate is also extremely slow.

For this reason, the polymer absorber alone cannot be said to be effective as a humidity control agent.

However, by using a mixture of a porous adsorbent and a polymer absorber, it quickly absorbs a large amount of moisture in humid conditions, and releases moisture in dry conditions, allowing it to quickly and over a long period of time absorb moisture. This resulted in a humidity regulating effect.

1 to 5 are cross-sectional schematic model views showing structural examples of a moisture-absorbing and desorbing sheet-like article according to the present invention, which are all embodiments of the moisture-absorbing and desorbing article of the present invention.

As shown in these figures, the moisture absorbing and desorbing sheet material 1 according to the present invention is roughly divided into two parts: a moisture regulating part and a reinforcing part, which play the role of absorbing, releasing and storing moisture. It is.

That is, the embodiments shown in FIGS. 1 to 3 consist of a layer made of a mixture 2 of porous adsorbent and polymeric absorber, and a breathable reinforcing sheet material 4, with the former being The mixture layer is the moisture regulating part, and the latter sheet-like material is the reinforcing part. In addition, the embodiments shown in FIGS. 4 and 5 have a layer 3 made of a porous adsorbent in addition to a layer 2 made of a mixture of a porous adsorbent and a polymer absorbent as a moisture regulating section. It is arranged on one side (FIG. 4) or both sides (FIG. 5) of the layer of the mixture 2 so that the moisture regulating section is constituted by a multi-layer structure of at least two layers. By using a plurality of layers, a more preferable moisture regulating effect can be obtained.

The sheet material 4 has the purpose of reinforcing the humidity adjustment section to maintain its sheet form, and also plays an auxiliary role in making it easier for the humidity adjustment section to absorb and release moisture from the atmosphere. The sheet-like material 4 may be flexible or rigid as long as it is substantially sheet-like.

In the moisture absorbing and desorbing sheet material of the present invention, since the moisture regulating part is reinforced with the breathable sheet material of the reinforcing part, the form of the sheet material is firm, and it is easy to use at the place of use, environment, etc. By appropriately selecting the sheet material according to the situation, it can be suitably used in any location.

In the present invention, porous adsorbents include pentonand, seviolite, zeolite, activated alumina, dinolyte l-
1 activated carbon, molecular sieves, silica gel, silica alumina, etc., which have been generally used as adsorption materials in the past, and these materials may be used alone or in mixtures.

Among these, activated carbon, zeolite, and activated alumina are particularly effective for the purpose of the present invention, and are preferably used. Furthermore, among these, activated carbon is particularly preferably used.

Activated carbon is well known as an adsorbent, but it is also called a hydrophobic adsorbent, and it selectively adsorbs non-polar substances, making it ideal for removing bad odors, purifying the air, and removing trace amounts of organic matter in water. It is a material. However, since it has a particularly low moisture adsorption capacity compared to other porous adsorbents, it has rarely been used for the purpose of moisture adsorption. However, although activated carbon has a low moisture adsorption capacity, it has an extremely fast adsorption rate, and after adsorbing moisture, it quickly expels moisture in a dry atmosphere, that is, its release rate is extremely fast. There is. Among the above-mentioned porous adsorbents, activated carbon has particularly remarkable properties, and the present invention can utilize these properties particularly effectively.

In particular, when activated carbon is used in the present invention, the type of activated carbon is not particularly limited, and is generally used for purposes such as gas purification, solvent recovery, decolorization, water purification, and wastewater treatment. I don't mind.

That is, on the raw material side, any of wood, sawdust, coconut shell, lignin, cow bone, blood, cut charcoal, day charcoal, and coal may be used.By form, powdered activated carbon, powdered activated carbon,
Any type of granulated activated carbon may be used, and depending on the manufacturing method, there are steam activation methods, chemical activation methods, air,
Charcoal heated in carbon dioxide or chlorine gas to partially oxidize charcoal, charcoal heated under reduced pressure, red-hot charcoal heated in water,
Any of those soaked in nitric acid can be used. especially,
The larger the specific surface area and the more pronounced the porous structure, the more preferably used.

In addition, in the present invention, as the polymer absorbent, modified starch, cellulose type, starch-acrylonitrile graft polymer, polyacrylonitrile derivative, polyacrylamide type and polyacrylate type, vinyl acetate/
Super water-absorbing resins with extremely high water-absorbing capacity, such as methyl acrylate copolymer filaments and cross-linked polyacrylate polyvinyl alcohol cross-linked polymers, are preferably used. Among these, starch-acrylonitrile graft polymers and crosslinked polyacrylate polyvinyl alcohol crosslinked polymers have high water absorption ability and are preferably used.

These polymer absorbers may be used alone or in combination of two or more. Further, the form thereof may be granular, powder, film, block, etc., and the particle size and size are not particularly limited, but it is preferable to use it in a state with a large surface area.

The mixing ratio in the mixture of porous adsorbent and polymeric absorbent varies depending on the amount of humidity in the atmosphere or the desired humidity conditions suitable for the target object. It is preferable to set it within the range of body-5/95 to 9515. When the required humidity is low, it is preferable to increase the content ratio of the porous adsorbent, and conversely, when the humidity is high, it is preferable to increase the content ratio of the polymer absorber. In addition, in the thickness direction, it is preferable to have a structure in which the content ratio of the porous adsorbent is increased closer to the surface layer, and the content ratio of the polymer absorber is increased closer to the inner layer.

In some cases, it is also preferable to allow the material to absorb excessive moisture in advance and then use it in an atmosphere.

The method for obtaining such a mixture of porous adsorbent and polymeric absorber is not particularly limited, and examples include the Raikai machine,
A method of mixing while stirring, a method of mixing while kneading, a method of mixing in a rotating container, etc. using a device such as a stirrer or a kneader can be used.

Moreover, it is also preferable to use a mixture obtained by adding a liquid such as water to such a compound, mixing it, making it into a slurry or paste, casting it, and then drying it.

Further, FIG. 6 is also a cross-sectional schematic model diagram showing a structural example of the moisture absorbing and desorbing sheet-like material 1, which is an embodiment of the moisture absorbing and desorbing material of the present invention. This shows an example in which 5 and the polymer absorbent 6 are mixed in a layered or block form, respectively.In this way, the porous adsorbent 3 can be mixed within a range that does not impair the effects of the present invention. and the polymer absorber each exhibit a collective structure, and each of the collective structures may be used in combination.

The method of reinforcing with a breathable sheet material is not particularly limited, and may include a method of recoating the moisture regulating portion in the form of a slurry or paste described above on a breathable sheet material, or a method of recoating the moisture regulating portion in the form of a slurry or paste, or using a press machine. Methods such as crimping the two together, or forming a flexible breathable sheet material into a bag and placing the moisture regulating section therein may be used.

In addition, the mixed layer of porous adsorbent and polymer absorber in the humidity adjustment section and each porous adsorbent layer are designed to maintain their shape and reduce costs without significantly reducing their ability to absorb or release moisture. Other components may be mixed and used as long as the effects of the present invention are not impaired. In that case,
For example, gypsum, cement, calcium silicate, rock wool, calcium carbonate, basic magnesium carbonate, sodium aluminum silicate, aluminum hydroxide, magnesium hydroxide, titanium oxide, magnesium oxide, -4 clay, talc, calcium sulfate, chloride Calcium and the like are preferably used.

The breathable sheet-like material for reinforcing the humidity adjustment section is used to maintain the sheet-like form of the humidity adjustment section and to play an auxiliary role so that the humidity adjustment section can easily absorb and release moisture from the atmosphere. It is preferable to use a material with low resistance to moisture passage, but any material can be used as long as it allows at least moisture to pass through, and is not particularly limited. For example, as the form of the breathable sheet-like material, nonwoven fabric, paper, porous film, woven fabric, knitted fabric, etc. can be used alone or as a composite. Among these, non-woven fabrics are preferred because they can be freely designed in terms of sheet texture, thickness, density, etc., have a smooth surface, can be cut out, are cheap, and are easy to post-process. . Furthermore, the sheet-like material may be flexible or rigid as long as it is substantially sheet-like.

The air-permeable sheet material must be used on at least one side of the moisture adjustment section, and may be used on both sides or surrounding the moisture adjustment section. When used on one side, the other side may be laminated or covered with any other sheet-like material or other form, which should be selected appropriately depending on the purpose, use, installation location, etc. Bye.

In such a breathable sheet-like material, its density, thickness, etc.
In addition, when using textiles such as knitted fabrics and non-woven fabrics, the sheet date, fiber thickness, composition, etc. should be determined appropriately depending on the purpose, use, installation location, etc., and are not particularly limited. Although it is not necessary, it is of course preferable that the structure is such that it can easily absorb and release moisture under the conditions of use.

For example, in the case of fibers, it is preferable that the thickness of the fibers be as thin as possible, and in particular, those with a single filament fineness of 1-denier or less, which are called ultrafine fibers, are preferably used. In addition, there are pile-like fibers with a large fiber surface area, -6-raised fibers, fibers with an uneven shape on the surface, fibers with a hollow cross section, and fibers treated with water absorption using surfactants. It is also preferably used. As the fiber component, natural fibers such as cotton and linen, and synthetic fibers such as nylon, polyester, polyethylene, polypropylene, and polyacrylic fibers can be used.

Among these, for materials used under severe conditions such as building materials, synthetic fibers such as nylon, polyester, polyethylene, polypropylene, and polyacrylic fibers, which are less susceptible to corrosion and decomposition, are preferably used.

In addition, in porous films, the moisture vents are
A film that is mechanically perforated or a film that itself has micropores or pores can be used.

Furthermore, depending on the purpose, of course, such breathable sheet-like materials can be dyed or printed with various patterns and colors such as flower patterns and woodgrain patterns, and can also be used as character products. Of course, it is also possible to use a high-class appearance as a breathable sheet-like material and finish it with an appearance, shape, and form that at first glance would be hard to believe that it is a material for absorbing and releasing moisture. can.

The moisture-absorbing and desorbing sheet-like material according to the present invention can be made into a block shape like quilting by sewing or fusing the sheet-like material at an appropriate location such as the center of the sheet depending on the size of the sheet-like material. A preferred structural example is to partition the chamber and include a moisture regulating section therein.

The moisture absorbing and desorbing sheet material according to the present invention can be used as a rug on and/or under a tatami mat or carpet, a rug under a floor, a wall covering material,
By using sheets on ceilings that also have a heat-insulating effect, sheets on floors and/or underlays in kitchens, washrooms, toilets, etc., or foot-wiping mats, they can adjust humidity to the desired level, prevent corrosion of buildings, and make buildings more comfortable. Able to provide a sanitary environment.

In addition, it can be used by placing it in an appropriate container, or by forming a container itself using the moisture absorbing and desorbing sheet material of the present invention on the entire surface or a part thereof, and using it as a container having moisture absorbing and desorbing properties. 8 By using it in this way, it is suitable for preserving the freshness of fresh foods such as vegetables, fruits, meat, fish, etc., or for preserving crafts, art, folk art, clothing, leather, etc. It is possible to provide a high humidity environment.

[Examples] Hereinafter, the present invention will be explained in more detail with reference to Examples, but it goes without saying that the present invention is not particularly limited to these Examples.

It should be noted that all percentages are based on weight unless otherwise specified.

Example 1 As a moisture adjustment part, zinc chloride activated powder activated carbon, starch-acrylate graft polymer, clay, and calcium carbonate were used as zinc chloride activated powder activated carbon/starch-acrylate graft polymer/clay/calcium carbonate=40 /3
A ratio of 5/15/10 was prepared, water was added to it, and then kneaded into small pieces using a Raikai machine to form a slurry, and the slurry was cast onto a stainless steel vat.-9 Hot air dryer A sheet of 320g/n was made by drying.

Further, as a reinforcing portion, a bag-shaped polyester nonwoven fabric having a single fiber denier of 0°2 denier was prepared.

The moisture regulating sheet described above was inserted into the reinforcing bag and the opening was sewn with a sewing machine to produce a moisture absorbing and releasing sheet according to the present invention.

This moisture absorbing and releasing sheet was left at 20°C and 30% RH for 24 hours, and then placed in a desiccator whose temperature and humidity were adjusted to 40°C and 195% RI-1, and changes in humidity inside the sheet were examined (implemented). Example 1-).

As comparative examples, a sheet containing only a starch-acrylate graft polymer (Comparative Example 1) and a sheet containing only zinc chloride-activated powder activated carbon (Comparative Example 2) were prepared, and changes in humidity were measured in the same manner. Examined.

As a result, it was found that in the sheet according to the present invention, the humidity decreased quickly and maintained for a long time, as shown in FIG.

Further, the sample was dried to a near-zero dry state using a hot air dryer, and placed in a constant temperature and humidity chamber adjusted to 40° C. and 95% RH to examine the state of moisture absorption. As a result, it was found that the sheet according to the present invention quickly absorbs moisture and absorbs a large amount of moisture, as shown in FIG.

Conversely, after being left under such absorption conditions for 48 hours, each sample was placed in a constant temperature and humidity chamber adjusted to 40° C. and 30% RI-T, and the state of water release was examined.

As a result, it was found that the moisture absorbing and desorbing sheet of the present invention rapidly releases moisture, as shown in FIG.

Example 2 As a moisture adjustment part, zinc chloride activated powder activated carbon, starch-acrylate graft polymer, and clay were used in a ratio of zinc chloride activated powder activated carbon/starch-acrylate graft polymer/clay = 40/40/20. After adding water to this, knead it into small pieces using a Raikai machine (J4J) to form a slurry, then cast this slurry onto a stainless steel vat and dry it with a hot air dryer to obtain a fabric weight of 350.
A sheet-like material of g/1 d was made (hereinafter referred to as layer A).

Furthermore, a mixture of zinc chloride activated powder activated carbon and calcium carbonate (zinc chloride activated powder activated carbon/calcium carbonate = 70
/30), then knead it into small pieces using a Raikai machine, cast it on a stainless steel vat as a slurry, and dry it with a hot air dryer to make 150g of dates.
+1 (hereinafter referred to as layer B).

The A layer and the B layer are laminated like B/A/'H to form a moisture regulating section, and a reinforcing section is made of a polyester melt-blown nonwoven fabric having a single yarn of 0.14 denier to form the moisture regulating section. The moisture absorbing and desorbing sheet according to the present invention was prepared by covering both sides of the sheet and sewing the periphery with a sewing machine.

The moisture-absorbing and desorbing sheet according to the present invention was spread under a highly humid floor, and the degree of corrosion of a piece of cypress wood placed on the sheet was observed one year later.

As a result, without laying the sheet of the present invention under approximately the same conditions,
It is clearly clear that the cypress wood pieces placed on the sheets of the present invention have a higher The degree of corrosion on the wood pieces was slight. Moreover, under the floor where the sheet according to the present invention was not laid,
There was a large amount of white, cotton-like mold under the floor where the sheets of the present invention were spread.

[Effects of the Invention] As described in 2 below, the moisture absorbing and desorbing material of the present invention uses a mixture of a porous adsorbent and a polymer absorber, so that it can quickly and for a long time in humid conditions. The ability to reduce humidity over time, and in dry conditions, gradually release absorbed moisture and return to a certain humidity state.
It has a so-called reversible humidity control function.

With such a humidity control function, the moisture absorbing and desorbing material according to the present invention, the moisture absorbing and desorbing sea!・Products such as tatami mats, carpets, etc.
Or use it as a rug under the floor, a rug under the floor, a wall covering, a sheet placed on the ceiling that also has a heat-insulating effect, a sheet for the top and/or under the floor of the kitchen, washroom, toilet, etc., or a foot-wiping mat, etc. 3, it is possible to adjust humidity in a preferable manner, prevent corrosion of buildings, and provide a comfortable and sanitary environment.

In addition, by placing it in an appropriate container or using it on the entire surface or a part of the container itself, it can be used to maintain the freshness of foods such as vegetables, fruits, meat, fish, and other perishable foods, or for crafts. It is possible to provide a humid environment suitable for preserving goods, works of art, folk crafts, clothing, leather, etc.

[Brief explanation of drawings]

1 to 6 are cross-sectional schematic model views showing structural examples of a moisture-absorbing and desorbing sheet-like article according to the present invention, which are all embodiments of the moisture-absorbing and desorbing article of the present invention. FIGS. 7 to 9 are graphs showing examples of moisture absorption and release characteristic data explained in Example 1. 1: Moisture absorbing and releasing sheet material according to the present invention 2, mixture of porous adsorbent and polymer absorber 3: porous adsorbent 4: breathable sheet 5: porous adsorbent 4: polymer absorber 5 Figure 7 Figure 8

Claims (6)

[Claims] (1) A moisture-absorbing and desorbing material comprising a mixture of a porous adsorbent and a polymer absorbent. (2) The moisture absorbing and desorbing material according to claim (1), wherein the porous adsorbent is activated carbon. (3) The moisture regulating section is made of a mixture of a porous adsorbent and a polymeric absorber, and one side, both sides, or the periphery of the moisture regulating section is reinforced with a breathable sheet-like material. Wet sheet material. (4) The moisture adjustment section has at least two layers: a layer made of a mixture of a porous adsorbent and a polymer absorber, and a layer made of a porous adsorbent above (front side) and/or below (back side). 1. A moisture-absorbing and desorbing sheet-like material having a layered structure, wherein one side, both sides, or the periphery of the moisture-adjusting section is reinforced with an air-permeable sheet-like material. (5) The moisture absorbing and releasing sheet according to claim 3 or 4, wherein the breathable sheet is made of one or more of nonwoven fabric, paper, porous film, woven fabric, and knitted fabric. thing. (6) A container having moisture absorbing and desorbing properties, characterized in that it is made entirely or partially using the moisture absorbing and desorbing sheet material according to any one of claims (3) to (5).