JPH1148386A - Manufacture of moisture-absorbent/desorbent article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a moisture-absorbent/desorbent article excellent in molding processing characteristics and having variables of various physical properties and the large degree of freedom in a range of selection. SOLUTION: A liquid composition prepared by dispersing a material, which allows a volatile substance to be adsorbed in particles P of a moisture-absorbing/desorbing agent, in a liquid resin is molded to the shape of a predetermined article under the condition that the volatile substance is not discharged. Then, the liquid composition is solidified under the condition that the volatile substance in the particles P of the moisture-absorbing/desorbing agent is volatilized and discharged. By this method, the predetermined article is formed into a structure that the particles P of the moisture-absorbing/desorbing agent are added to and dispersed in the resin R having therein many cavities (a) opening to the surface of the article. Thereby, moisture-absorption/desorption properties can be sufficiently imparted to the article without adding an extremely large amount of the absorbing/desorbing agent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a material having moisture absorption and desorption properties, which is used for various purposes including materials for building and storage containers or interior materials.

[0002]

2. Description of the Related Art Heretofore, in order to reduce the range of changes in humidity inside a building, storage container, or the like with respect to changes in the temperature and humidity in the outside world, the interior material has been made of a material having a hygroscopic property. . For example, a building or a storage container is made of a material which itself has moisture absorption and release properties, such as traditional wall clay, wood (particularly paulownia wood), or a material such as metal or resin which has insufficient moisture absorption and release properties. Silica gel and activated clay (montmorillonite) inside buildings and storage containers made of various materials
And so on.

[0003]

According to the former method described in the prior art, plasterers need to coat with a trowel or the like for wall soil, and cut with a saw or plane for wood. ,
Since it is necessary to cut and grind and then join with nails, adhesives, etc., there is a problem that the efficiency of the manufacturing process is low, and further, the forming process such as bending and drawing is poor. In addition, physical properties such as water resistance and abrasion resistance are also insufficient depending on the application, and in such a case, these materials have a small degree of freedom in changing the physical properties, and the physical properties can be improved by selecting the materials themselves. Was difficult.

In the latter method, for example, placing a bag or the like containing silica gel or the like requires a space for that purpose, so that in the case of a container, the effective space is reduced by that much, and in the case of a building, Then, there was a problem that it was in the way (if it was placed on the floor, it would be a hindrance to walking).

[0005] Therefore, it has been attempted to add and disperse the moisture absorbing and releasing agent to a resin which is excellent in molding processability and has a large degree of freedom in variable and selection ranges of various physical properties but has no moisture absorbing and releasing properties.
However, since the desiccant is covered and sealed with resin,
The moisture absorption / release effect is greatly reduced. If a very large amount of moisture absorbing and releasing agent is added, the moisture absorbing and releasing effect is slightly improved because a part of the moisture absorbing and releasing agent is exposed on the resin surface, but the resin becomes brittle instead. However, there were problems such as insufficient strength and deterioration of surface physical properties such as abrasion resistance and the like, and there was no practicality.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and it is an object of the present invention to provide a material having excellent molding workability and a large degree of freedom in changing and selecting various physical properties. An object of the present invention is to provide a method for manufacturing a wet article.

[0007]

According to a first production method of the present invention, a liquid composition obtained by dispersing a substance obtained by adsorbing a volatile substance in moisture-absorbing / desorbing agent particles in a liquid resin is vaporized. It is characterized in that the liquid composition is solidified in a state in which the volatile substance in the moisture absorbent / release agent particles is volatilized and released, in a state in which the volatile substance in the moisture absorbent / release agent particles has been volatilized and released, in a state where the volatile substance has not been released.
The moisture-absorbing / desorbing article obtained by this method is obtained by adding and dispersing the moisture-absorbing / desorbing agent particles P in a resin R having a first type as shown in FIG. It becomes the structure which consists of.

The moisture-absorbing and desorbing article to be finally formed is of a second type as shown in FIG. 2, that is, a cavity a opening on the surface of a substrate B made of an arbitrary material.
Adding moisture absorbing / releasing agent particles P to the resin R having a large number of
A configuration in which the moisture-absorbing and desorbing resin layers L dispersed are laminated may be used.

A method of manufacturing a second type of article as shown in FIG. 2 is a second manufacturing method according to the present invention,
In this method, a liquid composition obtained by dispersing a volatile substance adsorbed in a moisture absorbing / desorbing agent particle in a liquid resin is applied to the surface of a substrate in a state where the volatile substance is not released. Then, the liquid composition is solidified in a state in which volatile substances in the moisture absorbing / releasing agent particles are volatilized and released. Alternatively, a liquid composition obtained by dispersing a volatile substance adsorbed in a moisture absorbing / desorbing agent particle in a liquid resin is coated on a support sheet in a state where the volatile substance has not been released, Next, after the volatile substance in the moisture absorbing / releasing agent particles is volatilized, the liquid composition is solidified in a state of being released, and then separated from the support sheet to form a sheet-like moisture absorbing / releasing resin layer. It is characterized in that the moisture-absorbing / releasing resin layer is bonded to the substrate surface with an adhesive.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, a resin which does not have (or is poor in) moisture absorption / desorption itself but has excellent molding workability and has a high degree of freedom in variable and selection ranges of various physical properties. Use according to the application. This resin is appropriately selected from the following (1) to (3). (1) Polymethyl (meth) acrylate, polyethyl (meth) acrylate, polybutyl (meth) acrylate, methyl (meth) acrylate / butyl (meth) acrylate copolymer, methyl (meth) acrylate / ethyl (meth) acrylate copolymer (Meth) acrylate means acrylate or methacrylate), polyethylene terephthalate, polybutylene terephthalate, ethylene terephthalate / isophthalate copolymer Thermoplastic polyesters such as polymers, polyethylene, polypropylene, polyolefins such as olefinic thermoplastic elastomers, polyvinyl fluoride, polyvinylidene fluoride, polytetrafluoroethylene,
Fluorine resin such as ethylene / tetrafluoroethylene copolymer, polyvinyl chloride, butyral resin, polystyrene, ABS
(Acrylonitrile-butadiene-styrene copolymer), thermoplastic resins such as polycarbonate. (2) Thermosetting resins such as unsaturated polyester resins, epoxy resins, phenol resins, melamine resins, urea resins, and two-component curable polyurethane resins. (3) Monomers such as trimethylolpropane tri (meth) acrylate and dipentaerythritol hexa (meth) acrylate, and prepolymers or polymers such as urethane (meth) acrylate, epoxy (meth) acrylate and triazine (meth) acrylate And a monomer having a polymerizable functional group such as a (meth) acryloyl group and an epoxy group in the molecule, or a prepolymer or polymer.

The cavity opening to the surface is a cavity communicating from the inside of the resin article to the surface of the resin article. It is preferable that such a plurality of cavities communicate with each other and the communicating cavities are distributed to the inside of the resin article because the moisture absorption / release effect is good. The cavity may communicate from the front surface to the back surface of the article. The articles of the present invention have a large number of such cavities, and a uniform or substantially uniform distribution throughout the article, at least near the surface of the article. Of course, cavities that do not open on the surface may exist in parallel with cavities that open on the surface.

The diameter of the hollow body is usually 10 to 1000 μm.
m. The cavity body may be open directly to the article surface, or may be connected to the article surface by a passage. The diameter of the passage is also in the same range as the diameter of the cavity body. The shape of the hollow body may be a sphere, a spheroid, a polyhedron, or other various shapes. The cavity main body and the wall surface of the passage are made of a resin constituting the resin article.

The moisture absorbing / releasing agent particles are selected from those which do not dissolve in water, do not deteriorate even when exposed to air for a long time, and can repeatedly absorb and release moisture. For example, particles of moisture-absorbing and releasing inorganic substances such as shells such as activated clay (montmorillonite), ettringite, tobermorite, and scallop, and have a particle size of 0.1 to 1
It is about 00 μm. Alternatively, it may be a saponified graft copolymer of starch and acrylonitrile, a cross-linked polyvinyl alcohol, a salt of a reaction product of polyvinyl alcohol and maleic anhydride, rice hulls, and particles of a moisture-absorbing and releasing organic substance such as wood. The amount of the moisture absorbent particles added to the resin is 10 to 50.
% By weight.

Articles of the first type can take various shapes including sheets, flat plates, curved and deformed curved plates, columnar bodies such as polygonal columns and cylinders, and the like. What is necessary is just to make it an appropriate shape according to a use. In addition, as its uses, interior materials of buildings such as walls, floors, ceilings, interior materials of vehicles such as cars, trains, ships, aircraft, etc., furniture such as doors, window frames, handrails, furniture such as chests, Partitions, containers, and others can be mentioned.

The second type of article is obtained by laminating a hygroscopic resin layer on the surface of a base made of any material.
Examples of the material of the base include wood, iron, copper, such as wood veneer, wood plywood, particle board, and wood fiber board (MDF, etc.).
Metals such as aluminum, resins such as polyvinyl chloride, acrylic resin, polyolefin resin, polyester resin, ABS resin, phenolic resin, glass, ceramics such as ceramics, non-ceramic ceramic materials such as gypsum, calcium silicate, cement, paper, There are a cloth and a nonwoven fabric. The shape can take various shapes similarly to the above-mentioned article. In addition, the usage is the same as described above.

Examples of volatile substances include water, alcohols such as ethyl alcohol and methyl alcohol, paraffinic hydrocarbons such as hexane and pentane, aromatic hydrocarbons such as toluene and xylene, and ethyl acetate and butyl acetate. Esters, ketones such as acetone and methyl ethyl ketone, and dimethylformamide are exemplified.

As the resin of the liquid composition, a liquid resin is used without using a volatile diluent or dispersant.
As the degree of “liquid”, gas generated by volatilization from the moisture absorbing and releasing moisture particles generates bubbles in the resin, and the resin is softened to such an extent that at least a part of the bubble group can be opened on the resin surface. Just do it. For example, there are the following (1) to (3). (1) A thermoplastic resin in a molten state. In the case of this resin, the volatile substance adsorbed by the moisture absorbing and releasing agent is released by the heat at the time of heating and melting. (2) Uncured liquid of thermosetting resin. In the case of this resin, the volatile substance adsorbed by the moisture absorbent is released by the heat at the time of curing. (3) An uncured liquid material of an ionizing radiation-curable resin that is cured by ionizing radiation such as ultraviolet rays and electron beams. In the case of this resin, the volatile substance adsorbed by the moisture absorbent is released by heating or the like.

In order to manufacture the first type of article, for example, the following methods (1) and (2) are used. (1) The liquid composition is released from a support sheet (process paper, etc.)
The composition was coated thereon to form a sheet (film), and the volatile substance was volatilized from the moisture-absorbing / desorbing agent particles, and the composition was made porous by generating air bubbles having a large number of cavities open to the surface. After solidifying the liquid composition in the state, it is released (released) from the support sheet. (2) By injecting the liquid composition into the male and female molds of a predetermined shape and volatilizing the volatile substance from the moisture-absorbing / desorbing agent particles to generate air bubbles having a large number of cavities opened on the surface of the composition. After solidifying in a porous state, it is released from the mold.

In order to manufacture the second type of article, a liquid composition is applied to the surface of a substrate made of an arbitrary material, and the volatile substance is volatilized from the moisture absorbing / desorbing agent particles to form the composition on the surface. Either solidify in a porous state by generating air bubbles having a large number of cavities open to the surface, or use a moisture-absorbing / desorbing resin layer formed by the method of the above (1) with an adhesive as a base. And stick them together.

It is to be noted that in order to assist in producing a porous structure having a large number of cavities opened on the surface therein, or to increase the thickness of the article to impart cushioning properties, the above-mentioned liquid composition is incorporated into the above-mentioned liquid composition. It is also a preferred embodiment to add the above foaming agent and foam the foaming agent at the same timing as or before or after the release of the volatile substance from the moisture-absorbing / desorbing agent particles. As the foaming agent, one that releases a gas by thermal decomposition is preferable. Specifically, organic blowing agents such as azodicarbonamide, azobisisobutyronitrile, 4-4′-oxybisbenzenesulfonylhydrazide,
Alternatively, an inorganic foaming agent such as sodium hydrogen carbonate may be used. The amount of the foaming agent is 1 to 100 parts by weight of the resin.
About 5 parts by weight.

If necessary, a decorative layer or a concavo-convex pattern may be provided on the surface of the article (or on the back side if the article is transparent) as long as the moisture absorption / release properties are not impaired. As the decorative layer, for example, there are a pattern printing layer provided by a known ink and a printing method, a metal thin film layer of aluminum or the like, and it is preferable to provide these not partially but partially. In addition, a decorative effect can be obtained by adding a known dye or pigment to the inside of the article within a range not impairing the moisture absorption / release properties and coloring the article. As the uneven pattern, there are irregularities such as hairline, satin finish, sand grain, leather crest, wood grain conduit groove, joints of tiles and bricks,
A known embossing method is used, or the liquid composition is applied to the surface of a peelable support sheet having an uneven pattern on the surface, and the liquid composition is made porous and solidified, and then the solidified liquid composition is peeled off. Then, a method of transferring an uneven pattern on the surface of the support sheet is used. At this time, care must be taken so as not to destroy the porous structure having a large number of cavities opened on the surface, and the latter method is more preferable from this point.

[0022]

【Example】

(Example) Activated clay (“V2R” manufactured by Mizusawa Chemical Co., particle size: 50 μm) was used as the moisture absorbing and releasing agent particles.
0 parts by weight was dispersed in 50 parts by weight of ethyl acetate and stirred, and ethyl acetate was adsorbed on the activated clay particles as a volatile substance. At this time, the weight increase of the activated clay by ethyl acetate was 20 parts by weight. This activated clay was dispersed in a polyvinyl chloride sol having the following composition (unit: parts by weight), and 70 g /
150 on top of the m ² of flame燃紙(Kojin made "WK-ADS")
After coating to a thickness of μm, the coating was heated at 190 ° C. for 1 minute to solidify the polyvinyl chloride sol coat layer, and at the same time, volatile substances in the moisture absorbent particles were volatilized and released. Thereafter, by heating at 210 ° C. for about 1 minute, the foaming of the polyvinyl chloride sol layer was completed to obtain a humidity control wall material sheet having a large number of cavities opened on the surface. The diameter of the cavity of the obtained sheet was 50 to 450 μm.

<Composition of Polyvinyl Chloride Sol> Polyvinyl chloride paste resin (“PSL-280” manufactured by Kaneka) 100 Plasticizer: DOP 60 Titanium dioxide (rutile type) powder 15 Calcium carbonate powder 50 Blowing agent: Azodicarbonamide ( Otsuka Chemical “AZ-L30” 3 Stabilizer (Kyodo Yakuhin “KF-838”) 1

(Comparative Example) 30 parts by weight of untreated activated clay as in the example were added to a polyvinyl chloride sol having the same composition as above, and a flame-retardant paper of 70 g / m ² (“WK-AD” manufactured by Kojin Co., Ltd.) was used.
S ”) was coated to a thickness of 150 μm. afterwards,
While heating at 190 ° C. for 1 minute to solidify the polyvinyl chloride sol coat layer, heating at 210 ° C. for about 1 minute completed foaming of the polyvinyl chloride sol layer to obtain a wall material sheet.

The humidity control performance of each of the wall material sheets obtained in the examples and comparative examples was compared. Specifically, inside dimensions 25 × 2
Prepare a 5 × 25 cm cubic aluminum case, attach the wall material sheet cut to a size of 25 × 25 cm to the inner wall surface of the aluminum case, and make it constant at the initial set temperature and humidity (20 ° C., 50% RH). After that, the aluminum case is sealed, and the outside air temperature is changed in a cycle of 0.5 hours at 20 ° C., 2 hours at 30 ° C., 2 hours at 20 ° C., and 2 hours at 10 ° C. to change the humidity inside the aluminum case. It was measured. FIG. 3 shows the obtained results. As can be seen from the graph of FIG. 3, when the wall material sheet of the comparative example was used, the humidity was + 40% with respect to the initial set humidity of 50% and −40%.
Although it fluctuated within the range of 20%, the degree of use of the wall material sheet of the example was able to keep the humidity within a range of approximately ± 10% with respect to the temperature change, and an excellent humidity control effect was recognized.

[0026]

As described above, according to the present invention,
It is possible to impart sufficient moisture absorption / desorption properties to articles without adding an extremely large amount of moisture absorption / desorption agents. In addition, therefore, the properties inherent to the resin such as molding workability, water resistance, abrasion resistance and the like and the range of variable and selectable properties thereof are not impaired. In addition, when the manufactured article is used, there is no need to separately place or attach a bag or the like containing a moisture absorbent, so that it does not take up space and does not become an obstacle.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a structural example of a first type article manufactured by a method of the present invention.

FIG. 2 is a sectional view showing a structural example of a second type article manufactured by the method of the present invention.

FIG. 3 is a graph comparing humidity control performances in Examples.

[Explanation of symbols]

 a cavity R resin P hygroscopic particles B base L hygroscopic resin layer

Claims (3)

[Claims] 1. A method for producing a moisture-absorbing / desorbing article by adding and dispersing moisture-absorbing / desorbing agent particles to a resin having a large number of cavities opened on the surface thereof, the method comprising: A liquid composition obtained by adsorbing a volatile substance in a liquid resin is molded into a predetermined article shape in a state where the volatile substance is not released, and then the volatile composition in the moisture absorbing / desorbing agent particles is formed. A method for producing a moisture-absorbing / desorbing article, comprising solidifying a liquid composition in a state where a substance is volatilized and released. 2. A moisture absorbing / releasing resin layer obtained by adding and dispersing moisture absorbing / releasing agent particles to a resin having a large number of cavities opened on the surface inside, on a surface of a substrate made of an arbitrary material. A method for producing a moisture-absorbing / desorbing article, comprising: dispersing a volatile substance adsorbed in moisture-absorbing / desorbing agent particles in a liquid resin into a liquid material in a state where the volatile substance has not been released. A method for producing a moisture-absorbing / desorbing article, comprising: applying a liquid composition to a surface of a substrate by heating and then volatilizing and releasing volatile substances in the moisture-absorbing / desorbing agent particles. 3. A moisture absorbing / releasing resin layer obtained by adding and dispersing moisture absorbing / releasing agent particles to a resin having a large number of cavities opened on the surface inside, on a surface of a substrate made of an arbitrary material. A method for producing a moisture-absorbing / desorbing article, comprising: dispersing a volatile substance adsorbed in moisture-absorbing / desorbing agent particles in a liquid resin into a liquid material in a state where the volatile substance has not been released. The liquid composition is solidified in a state where the volatile substances in the moisture absorbent / dehumidifier particles have been volatilized and released, and then separated from the support sheet to form a sheet-like absorbent sheet. A method for producing a moisture-absorbing / desorbing article, comprising forming a moisture-releasing resin layer into a film, and bonding the moisture-absorbing / desorbing resin layer to a substrate surface with an adhesive.