JP2003145688A - Moisture absorbing/desorbing material and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a moisture absorbing/desorbing material having excellent moisture absorbing/desorbing properties, preventing the surface thereof from becoming sticky and easy to damage even at the time of high humidity to hold a good surface state and absorbing moisture of aqueous paste applied to the back surface of wallpaper at the time of execution of the wallpaper by a water absorbable substance to generate no swelling, and a method for manufacturing the same simply. SOLUTION: A moistureproof resin film, a moisture absorbing/desorbing resin layer containing the water absorbable substance, a moisture permeable waterproof resin film and an aqueous resin layer are successively provided on a substrate material.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention absorbs moisture in the ambient air when the humidity is high, and diffuses the absorbed moisture into the ambient air when the humidity is low, thereby mitigating fluctuations in the humidity in the ambient air. The present invention relates to a moisture absorptive and desorptive material having such a function, and is particularly useful as an interior material for buildings.

[0002]

2. Description of the Related Art Modern buildings are compared with those of the former pure Japanese architecture due to the spread of reinforced concrete structures and prefabricated construction methods, new building materials made of synthetic materials such as resin-processed plywood, and the development of metal sashes in doors and windows. For example, it is extremely airtight. It can be said that the high airtightness of such a building is very desirable from the viewpoints of saving energy resources by improving the cooling and heating effect and preventing neighborhood noise pollution by improving soundproofing. However, on the other hand, the humidity generated by living activities of the resident (human breathing, cooking, bath / shower, etc.) in the room is easy to stay indoors without escape to the outside, and the humidity that has lost its place can be lost to the walls and windows. Condensation on the surface of glass, window frame sashes, etc. is not only aesthetically and tactilely undesirable, but also causes stains and corrosion of building materials, which may also shorten the life of the building. is there.

As a solution to this problem, some methods have been studied, such as a method of installing a forced ventilation device or an air conditioner in a building to keep indoor humidity always within a certain range. In addition, in order to perform forced ventilation or air conditioning for the entire interior of the building including the corridor and storage space, in addition to the initial capital investment burden becoming significantly heavy, it is necessary to install equipment at night and when going out. It is not considered to be a practical method for ordinary households because it costs a lot of electricity when it is operated for a long time, and it takes time and money to maintain and maintain the equipment.

Therefore, as a method of adjusting the indoor humidity without using the above-mentioned special equipment, the moisture in the ambient air is absorbed when the humidity is high, while the moisture which is absorbed when the humidity is low is transmitted to the ambient air. A method has been devised in which a moisture absorbing / releasing material having a function of diffusing is installed in a room to mitigate indoor humidity fluctuations. There are various possible modes of installing the moisture absorptive and desorptive material, but in order to exert the moisture absorptive and desorptive function quickly and sufficiently, it is considered that the larger the surface area in contact with the ambient air, the more advantageous it is. The most promising method is to finish a wall surface, a ceiling surface, or the like, which occupies a large surface area in a room, with an interior material such as wallpaper using a moisture absorbing / releasing material.

Concretely, as a wallpaper using the moisture absorptive and desorptive material described above, for example, in a normal wallpaper in which a foamed resin layer such as polyvinyl chloride resin is provided on a backing paper such as flame retardant paper,
The foamed resin layer is designed to have hygroscopicity by mixing hygroscopic inorganic powder such as silica gel or zeolite and super absorbent polymer such as acrylic resin or polyvinyl alcohol resin. ing.
However, the one using the hygroscopic inorganic powder does not necessarily have sufficient ability to mitigate humidity fluctuations in the room because the absolute amount of moisture absorption is small, and in that respect, a highly water-absorbing polymer with a large amount of absolute water absorption. However, on the other hand, since the super absorbent polymer swells and softens due to water absorption, the surface of the wallpaper tends to become sticky at high humidity, and when it is pressed or rubbed while absorbing water, it becomes wrinkled. There are problems such as easy deformation and scratches. In addition, there is a problem that the super absorbent polymer absorbs the water content of the water-based paste applied to the back surface of the wallpaper during the construction of the wallpaper to cause swelling.

In order to solve such a problem, from the resin composition containing no superabsorbent polymer on the surface of the moisture absorptive and desorptive resin layer containing the superabsorbent polymer, the strength of the resin composition is not likely to decrease even at high humidity. It is also conceivable to provide such a protective layer.
However, if the surface of the moisture absorptive and desorptive resin layer is covered with a protective layer made of a hydrophobic resin having excellent water resistance, this protective layer causes movement of moisture between the ambient air and the moisture absorptive and desorptive resin layer. Since it is difficult to obtain sufficient moisture absorption and desorption properties, it is considered desirable to form the protective layer with an aqueous resin having high moisture permeability. However, when it is attempted to apply a water-based coating solution consisting of an aqueous solution or dispersion of a water-based resin to the surface of the moisture absorptive and desorptive resin layer to provide a protective layer, during the coating of the water-based coating solution, Since the super absorbent polymer in the moisture absorptive and desorptive resin layer absorbs water contained in the aqueous coating solution and swells, there is a problem that a good coating state cannot be obtained. Also,
The problem that the super absorbent polymer absorbs the water content of the water-based paste applied to the back surface of the wallpaper when the wallpaper is applied and causes swelling cannot be solved.

[0007]

SUMMARY OF THE INVENTION The present invention has been made by paying attention to the above problems in the prior art. The problem is that it has excellent moisture absorption and desorption properties and high humidity. The surface does not become sticky or easily scratched even at times, and the surface condition is good, and the water-absorbing substance absorbs the water content of the water-based paste applied to the back surface of the wallpaper during wallpaper construction. It is an object of the present invention to provide a moisture absorbing / releasing material that does not swell and a production method capable of easily producing the same.

[0008]

The moisture absorptive and desorptive material of the present invention comprises a waterproof resin coating, a moisture absorptive and desorptive resin layer containing a water absorbing substance, a moisture permeable waterproof resin coating, and an aqueous resin on a substrate. Layers are provided in order, and in particular, the aqueous resin layer is a foam layer.

In the method for producing a moisture absorptive and desorptive material of the present invention, a waterproof resin coating and a moisture absorptive and desorptive resin layer containing a water absorbing substance are formed on a substrate, and the moisture absorptive and desorptive resin layer is permeated on the moisture absorptive and desorptive resin layer. A wet waterproof resin coating is formed, and thereafter, an aqueous coating solution containing an aqueous resin is applied onto the moisture permeable waterproof resin coating to provide an aqueous resin layer, and particularly,
A foaming agent is added to the aqueous coating liquid containing the aqueous resin, and the aqueous resin layer is formed into a foamed layer by being heated and foamed after being coated on the moisture-permeable waterproof resin coating. It is what

[0010]

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described in detail below with reference to the drawings. FIG. 1 is a schematic sectional view showing an embodiment of the moisture absorptive and desorptive material of the present invention.

In the moisture absorptive and desorptive material of the present invention, as shown in FIG. 1, the water content of the water-based paste applied to the back surface of the wallpaper when the wallpaper is applied on the surface of an appropriate base material 1 serving as a support will be described later. A waterproof resin coating 2 for preventing an absorbent material such as a super absorbent polymer from absorbing and swelling, and a moisture absorptive and desorptive resin layer 3 made of a resin composition containing a water absorbent material 32 such as a super absorbent polymer. The moisture absorptive and desorptive resin layer having moisture permeability to an extent that does not hinder the movement of moisture between the moisture absorptive and desorptive resin layer 3 and the ambient air, and at the time of coating the aqueous resin layer 5 described later. Three
A moisture-permeable waterproof resin coating 4 having waterproofness to the extent that water can be prevented from penetrating into the inside, and a protective layer made of an aqueous resin composition having high moisture permeability that does not prevent the moisture-absorbing / releasing function of the moisture-absorbing / releasing resin layer 3. And the aqueous resin layer 5 as the above are provided in this order.

The specific material and shape of the substrate 1 in the moisture absorptive and desorptive material of the present invention is not limited at all, and for example, a fibrous sheet such as paper, woven cloth or non-woven cloth, or a polyolefin resin sheet, Synthetic resin sheet such as polyester resin sheet, synthetic rubber sheet, acrylic resin plate or polycarbonate resin plate, ABS resin plate, synthetic resin base material such as FRP, plywood or laminated wood, fiber board, wood board such as particle board Material, metallic base materials such as steel plate, brass plate, aluminum plate, etc., inorganic base materials such as gypsum plate, calcium silicate plate, cement plate, concrete plate, etc. can be used, and any surface can be used. If necessary, appropriate surface treatment such as sealing treatment, base coat treatment, primer treatment, corona discharge treatment, ozone treatment, flame treatment, polishing treatment, etc. It may be.

In particular, when the moisture absorptive and desorptive material of the present invention is used as a wallpaper, any sheet-shaped material that has been conventionally used as a base material for a synthetic resin wallpaper can be used. Specifically, for example, a pulp paper-based flame-retardant paper obtained by impregnating a water-soluble flame retardant such as guanazine sulfanylate or guanazine phosphate into a paper-based paper made of cellulosic fiber such as wood pulp, or carbonic acid at the time of papermaking of cellulosic fiber. Inflammable paper or non-combustible paper such as inorganic mixed paper made by mixing inorganic agents such as calcium, aluminum hydroxide or magnesium hydroxide, inorganic fiber paper made by making inorganic fibers such as glass fibers or alumina fibers, and also flame retardants and inorganic materials Flame-retardant or non-combustible woven fabric or non-woven fabric produced by adding an agent or inorganic fibers,
Either can be used.

The waterproof resin coating 2 of the present invention may be any coating as long as it is waterproof enough to prevent the water of the aqueous paste applied to the back surface of the wallpaper from moving to the moisture absorptive and desorptive resin layer 3 when the wallpaper is applied. The composition is not particularly limited, but specifically, for example, the same acrylic resin, urethane resin, SBR resin, acetic acid as those exemplified as the substrate resin 31 of the moisture absorptive and desorptive resin layer 3 can be used. Vinyl resin, ethylene
A vinyl acetate copolymer resin, a silicone resin, a polyamide resin, a polybutene resin, a polyvinyl alcohol resin, etc. can be used. Even if one of these is used alone, a mixture or laminated coating of two or more kinds can be used. It may be.

If the thickness of the waterproof resin coating 2 is too thin, the waterproof property becomes insufficient, and the swelling of the water absorbing substance 32 in the moisture absorptive and desorptive resin layer 3 is sufficiently performed at the time of applying the aqueous glue during wallpaper application. If it is too thick, the radius of curvature will become large due to the thickening of the wallpaper layer when it is folded during wallpaper construction, and this will cause the surface to crack easily. Need to be set appropriately. When the resin composition constituting the waterproof resin coating 2 is selected from the above-mentioned various resins, for example, the thickness of the waterproof resin coating 2 is generally in the range of about 0.2 to 20 μm. Is preferred.

Moisture-absorbing and desorbing resin layer 3 in the moisture-absorbing and desorbing material
The water absorbent substance 32 is dispersed in the substrate resin 31. The substrate resin 31 may be any resin as long as it has a film-forming property, has a low water-absorption swelling property, and can maintain the layer form even when the water-absorbing substance 32 absorbs water. In order not to prevent absorption and diffusion of water between the volatile substance 32 and the ambient air,
High moisture permeability such as acrylic resin, urethane resin, SBR resin, vinyl acetate resin, ethylene-vinyl acetate copolymer resin, silicone resin, polyamide resin, polybutene resin, polyvinyl alcohol resin, etc. It is preferable to use a resin, and any one of them may be used alone, or a mixture of two or more kinds may be used.

The water absorbing substance 32 added to the moisture absorptive and desorptive resin layer 3 is a substance having a relatively sparse structure containing a lot of hydrophilic functional groups such as hydroxyl groups and carboxyl groups, and exceeds its own volume. Any substance capable of absorbing and storing a large amount of water inside may be used, and specifically, known general superabsorbent polymers and the like are used. For example, starch-acrylic acid graft polymer, starch-acrylonitrile graft polymer. , Cellulose-acrylonitrile graft polymer, polyvinyl alcohol cross-linked polymer, sodium polyacrylate cross-linked polymer, methyl acrylate-vinyl acetate copolymer saponified product and the like are used. It is also possible to use natural products such as potato starch and dextrins, and these water-absorbing substances can be used alone or in admixture of two or more.

The mixing ratio of the substrate resin 31 and the water-absorbing substance 32 in the moisture absorptive and desorptive resin layer 3 is not particularly limited in the present invention, but the substrate resin 31 is generally 20%.
It is desirable that the amount of the water-absorbing substance 32 is about 80% by weight and the amount of the water-absorbing substance 32 is about 80% by weight to 20% by weight. When the content of the substrate resin 31 is less than 20% by weight, it is difficult to sufficiently suppress remarkable deformation and strength reduction due to water swelling of the water absorbent substance 32 at high humidity, while the content of the water absorbent substance 32 is high. Is less than 20% by weight, it is difficult to obtain a sufficient moisture absorbing / releasing function. Although the thickness of the moisture absorptive and desorptive resin layer 3 is not particularly limited in the present invention, a sufficient moisture absorptive and desorptive function is exhibited,
Considering workability during manufacturing, flexibility during handling, and the like, it is generally desirable to set the thickness within the range of about 10 to 100 μm.

The substrate resin 41 in the moisture permeable waterproof resin coating 4 provided on the moisture absorptive and desorptive resin layer 3 described above.
Has moisture permeability to such an extent that it does not hinder the movement of water between the moisture absorptive and desorptive resin layer 3 and the ambient air, and is contained in the aqueous coating liquid at the time of coating the aqueous resin layer 5 described later. Any coating film may be used as long as it is a coating film made of a hydrophilic and water-resistant resin composition having a waterproof property to the extent that the moisture contained therein can be prevented from penetrating into the moisture absorptive and desorptive resin layer 3. The composition is not particularly limited. However, specifically, for example, the same acrylic resin, urethane resin, SBR resin, vinyl acetate resin, ethylene-acetic acid as those given as examples of the substrate resin 31 of the moisture absorptive and desorptive resin layer 3 are used. A vinyl copolymer resin, a silicone resin, a polyamide resin, a polybutene resin, a polyvinyl alcohol resin, or the like can be used, and one of these can be used alone or a mixture or laminated coating of two or more can be used. May

If necessary, the moisture-permeable waterproof resin film 4 may be
For example, silica gel, zeolite, diatomaceous earth, calcined talc, or the like, when a hygroscopic substance 42 made of particles of a porous hydrophilic inorganic substance having a large specific surface area is added, the humidity in the ambient air changes. It is also possible to improve the moisture absorption / desorption rate and to more effectively exert the humidity adjusting function. The reason is that the water-absorbing substance 32 such as a super-water-absorbing polymer is used.
In contrast, the hygroscopic substance 42 actively absorbs dew condensation water around it, while the hygroscopic substance 42 actively condenses gaseous water molecules at high humidity and transfers it to the water absorbing substance 32. On the other hand, when the humidity is low, on the contrary, it is presumed that the water-absorbing substance 32 has a function of receiving water contained therein and vaporizing it.

The amount of the hygroscopic substance 42 added is not particularly limited in the present invention, but the amount of water absorbed by the hygroscopic substance 42 itself is smaller than that of the water absorbent substance 32. If the hygroscopic substance 42 is added in a larger amount than that of the hygroscopic substance 42, the saturated water absorption amount is small, but the moisture absorption / desorption rate when the environmental humidity changes becomes high.
If a large amount of 2 is blended, the sensitivity to changes in environmental humidity will decrease, but the saturated water absorption will increase, so it may be designed appropriately according to the purpose of use. Generally, the hygroscopic substance 42 may be a smaller amount than the water-absorbing substance 32 in a catalytic sense of the water-absorbing substance 32, and the hygroscopic substance 42 may be contained in an amount of 30 to 100 parts by weight based on 100 parts by weight of the water-absorbing substance 32. It is desirable that the composition is about a part.

If the moisture-permeable waterproof resin coating 4 is too thin, the waterproofness becomes insufficient, and the water-absorbent substance 32 in the moisture-absorbing / releasing resin layer 3 is sufficiently swollen when the aqueous resin layer 5 is applied. However, if it is too thick, the moisture permeability will decrease, which will cause the moisture absorptive and desorptive performance of the moisture absorptive and desorptive resin layer 3 to be reduced.
It is necessary to set it in consideration of both. When, for example, one selected from the above-mentioned various resins is adopted as the resin composition constituting the moisture-permeable waterproof resin coating 4, the thickness of the moisture-permeable waterproof resin coating 4 is generally in the range of about 0.2 to 20 μm. It is preferable to set the inside.

The water-based resin layer 5 provided on the moisture-permeable waterproof resin coating 4 covers the surface of the moisture-absorbing / releasing resin layer 3 in order to prevent the surface from sticking and the surface strength from being reduced under high humidity or wet conditions. It is provided as a protective layer and can be applied in the form of an aqueous coating solution such as an aqueous solution or an aqueous dispersion so as not to impair the moisture absorbing / releasing function of the moisture absorbing / releasing resin layer 3, and
It may be made of a water-soluble resin 51 that is hydrophilic but water-insoluble and capable of forming a water-resistant layer after coating and drying, and may have a laminated structure of two or more layers made of the same or different materials. It doesn't matter.

Aqueous resin 51 which is the main component of the aqueous resin layer 5
Specifically, for example, water-soluble salt type acrylic resin, polyacrylamide, polyvinyl alcohol, polyvinylpyrrolidone, casein, cellulose derivatives, water-soluble resins such as dextrins, for example, melamine compounds, blocked isocyanate compounds, epoxy compounds, hydrazine derivatives, Those which have been made water-insoluble by adding a cross-linking agent such as aziridine or organic peroxide or by irradiation with ionizing radiation, for example, acrylic resin, polyurethane resin, SBR resin, vinyl acetate resin, ethylene acetic acid At least one or a mixture of two or more resins such as an aqueous emulsion resin obtained by dispersing water-insoluble resin particles such as a vinyl copolymer resin, a silicone resin and a polybutene resin in water can be used. From the viewpoint of stability of the coating liquid, surface physical properties after coating and drying, and high moisture permeability due to being in a microporous state, it is desirable to use an aqueous emulsion resin. Needless to say, the aqueous emulsion resin may be crosslinked by blending a crosslinking agent or irradiating with ionizing radiation.

If necessary, the aqueous resin layer 5 may be foamed into a porous cellular form by a known appropriate means such as a mechanical foaming method or a method of blending a foaming agent 52. By doing so, The moisture permeability of the aqueous resin layer 5 can be further improved, and the moisture absorbing / releasing function of the moisture absorbing / releasing resin layer 3 can be fully exerted. In addition, when the moisture absorptive and desorptive material of the present invention is used as an interior material such as a wallpaper in a building such as a house, the water-based resin layer 5 is foamed to facilitate the formation of the uneven pattern 7 by embossing, thereby improving the designability. Also, there is an advantage that an excellent interior material can be easily obtained.

Examples of the foaming agent 52 include azo compounds such as azodicarbonamide (ADCA), P and P '.
-Oxybis (benzenesulfonyl hydrazide) (O
BSH) or other nitroso compound or other organic foaming agent or sodium hydrogen carbonate or other inorganic foaming agent or other pyrolytic chemical foaming agent,
For example, polyacrylonitrile resin, phenolic resin,
An expandable microcapsule foaming agent in which a low-boiling liquid such as isobutane is contained inside a heat-softening flexible shell such as an epoxy resin can be used.

The amount of the foaming agent 52 added is not particularly limited in the present invention, but is generally 2 with respect to 100 parts by weight of the solid content of the aqueous resin 51 which is the main component of the aqueous resin layer 5. ˜20 parts by weight is preferably added, and more preferably 4 to 10 parts by weight. If the amount is less than 2 parts by weight, the expansion ratio is low, and the effect of improving the moisture absorption / release property cannot be expected so much, and it is also difficult to improve the design by the embossed uneven pattern 7. On the other hand, when the amount is more than 20 parts by weight, the foamed cells become extremely rough and the surface strength of the sheet may be weakened.

The water-based resin layer 5 may also include, if necessary,
For example, inorganic fillers such as calcium carbonate, barium sulfate, aluminum hydroxide and magnesium hydroxide, and coloring pigments such as titanium oxide and zinc oxide, dispersants, defoamers, wetting agents, flame retardants, and flame retardants. , An antibacterial agent, a fungicide, an ultraviolet absorber, a light stabilizer, a heat stabilizer, a lubricant, a luster modifier, an antistatic agent, an antiblocking agent, a thickener, and one or more kinds selected from various additives. It can also be added as appropriate.

The thickness of the water-based resin layer 5 is not particularly limited in the present invention, but if it is too thin, the effect of preventing stickiness and surface protection is poor, and if it is too thick, the moisture permeability decreases and the water absorption is reduced. Since the moisture absorbing / releasing function of the moisture releasing resin layer 3 is diminished,
It is necessary to design appropriately considering these. In general, it is preferably in the range of about 5 to 100 μm in the case of non-foaming, and in the range of about 20 to 2000 μm in the case of foaming.

The method for forming the waterproof resin coating 2, the moisture absorptive and desorptive resin layer 3, the moisture permeable waterproof resin coating 4 and the aqueous resin layer 5 described above is not particularly limited in the present invention, but the waterproof resin coating is not particularly limited. 2. The moisture absorptive and desorptive resin layer 3 and the moisture permeable waterproof resin coating 4 use an oily coating liquid having a hydrophobic organic solvent as a dispersion medium, and the aqueous resin layer 5 disperses water or a mixture of water and alcohols. Generally, a method of sequentially forming each by a coating method using an aqueous coating liquid as a medium is used. Examples of the coating method include knife coating method, nozzle coating method, gravure coating method, micro gravure coating method, rotary screen coating method, reverse loin coating method, comma coating method, lip coating method, die coating method, spray coating method, dip coating method. Any conventionally known coating method such as coating method and flow coating method can be adopted,
As a drying method after coating each layer, for example, a heat source such as hot air or an infrared heater may be used alone or in combination of plural kinds thereof.

The moisture absorptive and desorptive material of the present invention may optionally contain
It is also possible to provide a pattern print layer 6 on the surface of the water-based resin layer 5 to give a design property by the pattern. Examples of the printing method of the pattern printing layer 6 include a gravure printing method, a rotary screen printing method, a flexo printing method, an inkjet printing method,
A usual printing method such as a transfer printing method can be used. Further, in order to impart a three-dimensional design property, a concavo-convex pattern 7 is formed by a mechanical embossing method or a chemical embossing method, or a surface made of a moisture-permeable resin composition is added to further improve the surface strength. Providing a protective layer can also be arbitrarily performed.

[0032]

EXAMPLES The present invention will be described in more detail with reference to Examples and Comparative Examples of the present invention.

Example 1 An inorganic paper having a basis weight of 90 g / m ² was used as a base material, and a solvent-based urethane resin was first applied by a gravure coating method to a coating amount of about 1 g / m ² and dried. Then, a waterproof resin coating was provided. Subsequently, a moisture absorptive and desorptive resin composition having the following composition was applied by a comma coat method and dried at about 90 ° C. to provide a moisture absorptive and desorptive resin layer having a coating amount after drying of about 20 g / m ² . Then, on the moisture absorptive and desorptive resin layer,
A solvent-based urethane resin is applied by a gravure coating method to a coating amount of about 1 g / m ² and dried to form a moisture-permeable waterproof resin coating, and a microcapsule foaming agent is solidified on the moisture-permeable waterproof resin coating. Ethylene added with a ratio of 6 parts by weight
A vinyl acetate copolymer-based aqueous emulsion resin was applied by a comma coat method to a coating amount after drying of about 140 g / m ² and dried at about 90 ° C. to form an aqueous resin layer. Then, an abstract pattern is printed on the surface of the water-based resin layer by a gravure printing method, and then the water-based resin layer is foamed about 5 times in a foaming heating furnace having a furnace temperature of about 150 ° C. An embossed pattern was formed on the surface of the resin layer using a cooling embossing roll to prepare a wallpaper that is the moisture absorptive and desorptive material of the present invention.

[0034] [Formulation list of moisture absorbing / releasing resin composition] Water-absorbing substance Urethane-based highly water-absorbing polymer 40 parts by weight Hygroscopic substance Colloidal synthetic silica 30 parts by weight Substrate resin Polyurethane 90 parts by weight

The obtained wallpaper was free from defects such as coating unevenness in each layer, had a good appearance in terms of appearance, and did not swell due to the water content of the aqueous paste even during construction. Regarding this wallpaper, commercial vinyl chloride-based dew condensation prevention wallpaper (provided with a polyvinyl chloride resin foam layer with super absorbent polymer added to the backing paper) and commercially available non-condensation ordinary With the polyvinyl chloride wallpaper (provided with a polyvinyl chloride resin foam layer to which no superabsorbent polymer was added on the backing paper), the moisture absorption and desorption performance was measured by the following test method. It was confirmed that the wallpaper of Example 1, which is a moisture absorbing / releasing material, has extremely excellent moisture absorbing / releasing performance as shown in FIG.

<Test Method for Moisture Absorption / Desorption Performance> Sample is 6 cm × 2
It is cut into a size of 7 cm, and a 1 cm square on the front side and the entire back surface are covered with aluminum tape to prevent moisture permeation from the side and back surfaces. By the above treatment, the moisture permeable surface area of the sample is set to 100 m ^{2 of} 4 cm × 25 cm. The test piece thus prepared is allowed to stand for 4 days in a constant temperature and constant humidity tester set at a temperature of 25 ° C. and a relative humidity of 50%, and then the weight (a) of the test piece is measured, which is taken as an initial value. . next,
After allowing the test piece to stand for 144 hours in a constant temperature and constant humidity tester set to a temperature of 25 ° C. and a relative humidity of 90%, the temperature was set to 25
1 in a constant temperature and high humidity tester set to ℃ and relative humidity of 50%
The sample is left to stand for 44 hours, during which the weight (b) of the test piece is measured at appropriate time intervals. The moisture absorption amount of the test piece at each time is calculated by the following equation (1). Moisture absorption amount [g / m ² ] = (weight of test piece (b) [g] -weight of test piece (a) [g]) / moisture permeable surface area [m ² ] ··· (1)

<Comparative Example 1> In the above-mentioned Example 1, the process of forming the waterproof resin coating was omitted, and the wallpaper which is a moisture absorbing / releasing material was prepared and applied under exactly the same conditions as in Example 1 above. However, immediately after the aqueous paste is applied to the back surface of the wallpaper, the moisture absorptive and desorptive resin layer has a thickness ratio of 5 to 10 due to the water in the aqueous paste.
It swelled about twice and could not be satisfactorily constructed.

<Comparative Example 2> In the above-mentioned Example 1, the process of forming the moisture-permeable waterproof resin film was omitted, and the wallpaper which is a moisture-absorbing / releasing material was produced under the same conditions as in Example 1 except for the above. However, immediately after applying the aqueous coating solution of the aqueous emulsion resin for the aqueous resin layer on the moisture absorptive and desorptive resin layer,
The moisture absorptive and desorptive resin layer has a thickness ratio of 5 due to the water content of the aqueous coating liquid.
It swelled about 10 times, and it was not possible to obtain a hygroscopic material having a good surface condition.

[0039]

As described above in detail, the moisture absorptive and desorptive material of the present invention has a structure in which the waterproof resin coating is provided between the substrate and the moisture absorptive and desorptive resin layer containing the water absorbing substance. This effectively prevents the occurrence of a phenomenon in which the water-absorbing substance in the moisture-absorbing / releasing resin layer absorbs and swells due to the water contained in the water-based paste applied to the backside of the wallpaper when the wallpaper is applied, and contains the water-absorbing substance. A water-soluble resin layer is provided on the moisture-absorbing / releasing resin layer via a moisture-permeable waterproof resin film, so that the water-based coating liquid can be applied when the water-based coating liquid for forming the water-based resin layer is applied. Effectively prevent the occurrence of the phenomenon that the water-absorbing substance in the moisture-absorbing and desorbing resin layer is absorbed and swelled by the water contained in the liquid,
It is possible to stably obtain a moisture absorptive and desorptive material that does not swell during construction and has a good surface condition. Moreover, the moisture absorptive and desorptive material thus obtained absorbs moisture in the ambient air at high humidity and, on the other hand, dissipates the moisture absorbed at low humidity, thereby achieving an excellent humidity adjusting function, and the surface layer is Since it does not contain a water-absorbing substance, the surface does not become sticky or the surface strength does not decrease at high humidity, and it has the same surface properties and design as conventional wallpaper, for example. It has an excellent effect that a wet material can be easily obtained.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing an embodiment of a moisture absorptive and desorptive material of the present invention.

FIG. 2 is a graph showing the results of moisture absorptive and desorptive performance tests of Examples of the moisture absorptive and desorptive material of the present invention.

[Explanation of symbols]

1 ... Base material 2 ... Waterproof resin coating 3 ... Moisture absorbent resin layer 31 ... Substrate resin 32 ... Water-absorbing substance 4 ... Breathable waterproof resin coating 41 ... Substrate resin 42 ... Hygroscopic substance 5: Water-based resin layer 51 ... Water-based resin 52 ... Foaming agent 6 ... Picture print layer 7 ... uneven pattern

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) B32B 5/18 B32B 5/18 E04B 1/64 E04B 1/64 D F24F 1/00 451 F24F 1/00 451 6/04 6/04 F term (reference) 2E001 DB03 FA10 GA24 GA25 GA27 GA28 GA42 HA01 HA03 HA04 HA21 HA22 HA33 HB04 HB05 HC02 HC04 HC07 HD01 HD12 HD14 HE01 JA06 3L055 BA10 4D052 AA08 CA02 CA06 HA01 HA03 HA19 HA23 HA27 HB05 AB01 4F AA20H AK01B AK01C AK01D AK01E AK51 AK68 AT00A BA05 BA10A BA10E CA30C DE04H DG10 DJ01E EH461 EH462 EJ022 EJ402 GB08 JB09E JD04D JD04H JD05B JA05BJC15B JC05BJC15B JA15B JD15C JD15B JD15H

Claims (5)

[Claims] 1. A water-absorbing / releasing material comprising a waterproof resin film, a moisture-absorbing / releasing resin layer containing a water-absorbing substance, a moisture-permeable waterproof resin film, and an aqueous resin layer, which are successively provided on a substrate. Wet material. 2. The moisture absorptive and desorptive material according to claim 1, wherein the aqueous resin layer is a foam layer. 3. The moisture absorptive and desorptive material according to claim 1, wherein the moisture permeable waterproof resin film contains a moisture permeable substance. 4. A waterproof resin coating and a moisture absorptive and desorptive resin layer containing a water absorbing substance are formed on a base material, a moisture permeable waterproof resin coating is formed on the moisture absorptive and desorptive resin layer, and thereafter, A method for producing a moisture absorptive and desorptive material, which comprises applying an aqueous coating solution containing an aqueous resin onto a moisture-permeable waterproof resin coating to form an aqueous resin layer. 5. A foaming agent is added to the water-based coating liquid containing the water-based resin, and the water-based resin layer is formed into a foamed layer by heat-foaming after coating on the moisture-permeable waterproof resin coating. The method for producing a moisture absorptive and desorptive material according to claim 4, wherein the moisture absorptive and desorptive material is produced.