JP2003033624A - Granular humidity conditioner and underfloor humidity conditioning method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a granular humidity conditioner which consists of hydrate Fe-containing aluminium oxide of specified composition, effectively releases moisture retained under low moisture conditions and, moreover, shows a high hygroscopic property under high moisture conditions. SOLUTION: This granular humidity conditioner comprises granulate material of the hydrate Fe-containing aluminium oxide which has a specified chemical composition, BET specific surface area of >=200 m<2> /g and equilibrium moisture adsorptivity R75 at relative humidity RH 75% of 20%.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a granular humidity control agent and an underfloor humidity control method using the same, and more specifically, it is composed of a hydrated iron-containing aluminum oxide and has excellent humidity control performance and deodorant performance. It also relates to an excellent granular humidity conditioner.

[0002]

2. Description of the Related Art Conventionally, various construction methods have been performed for the purpose of controlling the humidity under the floor of a house. JP 62-
No. 202145 discloses that a moisture impermeable sheet is laid on the entire floor surface of the lower floor of a wooden house, and then a humidity-controlling powder or a humidity-controlling sheet is sprinkled or laid on the sheet to control the humidity of the lower floor. An underfloor humidity control method is described.

Japanese Unexamined Patent Publication (Kokai) No. 2-140342 describes an underfloor drying method characterized by spraying sepiolite and / or attapulgite on the surface of soil or concrete under the floor and rotating a fan to dehumidify. There is.

In Japanese Patent Laid-Open No. 4-55540, an aluminum sheet is laid so that the floor surface is leveled, and zeolite particles crushed and formed into an appropriate size are spread and laminated on the sheet. The underfloor conditioning method of the house is described.

Japanese Unexamined Patent Publication (Kokai) No. 10-131308 discloses a house humidity control agent characterized by comprising 10 to 90 parts by weight of expanded obsidian and 90 to 10 parts by weight of charcoal.

Japanese Unexamined Patent Publication (Kokai) No. 11-347341 discloses a heated dehydration product of 100 parts by weight of an amorphous silica-based mineral and 2.5 to 50 parts by weight of an alkali metal hydroxide, and has a bulk density of 0.1. A granular moisture absorbing / releasing material having a moisture absorbing / releasing rate of up to 1.2 g / cm ³ and 5% by weight or more is described.

[0007]

The humidity control agent can be defined as a material that releases moisture retained under low humidity conditions, while exhibiting hygroscopicity of moisture under high humidity conditions. Sepiolite is a relatively excellent combination of moisture-releasing property and hygroscopic property. However, sepiolite has a problem that the absolute value of saturated moisture absorption is still quite low, and that the amount of moisture absorption is particularly low especially under high humidity conditions. This seems to be due to the fact that sepiolite has a BET specific surface area and pore volume that are closely related to adsorption sites, which are considerably smaller than those of other adsorbents.

On the other hand, the B-type silica gel has an advantage that it has a high moisture absorption amount under high humidity conditions, but it has a low moisture releasing property under low humidity conditions and has a problem as a humidity control agent.
This is because the pores of B type silica gel are ink pot type,
It may be related to the fact that water is difficult to desorb.

The present inventors have succeeded in synthesizing a hydrated iron-containing aluminum oxide having a specific composition, and this hydrated iron-containing aluminum oxide has a relatively large BET specific surface area and saturation even though it contains iron. It has been found that it has a moisture adsorbing amount (RH 75%) and is also excellent in the action as a humidity control agent, and is useful as a granular humidity control agent, particularly as an underfloor humidity control agent.

The object of the present invention is a granular material consisting of a hydrated iron-containing aluminum oxide having a specific composition, which effectively releases the water retained under low humidity conditions, and which exhibits high hygroscopicity under high humidity conditions. To provide a humidity control agent. Another object of the present invention is to provide a method for effectively controlling the humidity under the floor by a simple means by using the above-mentioned granular humidity conditioner.

[0011]

According to the present invention SUMMARY OF], the following formula _{(1) xFe 2 O 3 ·} Al 2 O 3 · nH 2 O ‥ (1) wherein, x is the molar ratio 0.01 0.0, especially 0.03 to
0.4, and n is a number of 0 <n ≦ 4 in molar ratio, and has a BET specific surface area of 20.
Granules of hydrated iron-containing aluminum oxide having an equilibrium moisture adsorption amount (R ₇₅ ) of 0 m ² / g or more, particularly 250 m ² / g or more and a relative humidity (RH) 75% of 20% or more, particularly 25% or more. There is provided a granular humidity control agent, which comprises: In the granular humidity conditioner of the present invention, 1. 1. The average pore diameter is in the range of 30 to 100 angstroms, and the pore volume determined by the BET method is in the range of 0.50 to 1.20 ml / g. The moisture release amount (RM) defined by the following formula (2) RM (%) = R ₇₅ −R ₅₀ (2) is 5% or more, and the following formula (3) AM (%) = R ₉₀ −. The moisture absorption (AM) defined by R ₇₅ (3) is 8% or more,
R ₇₅ is the equilibrium moisture adsorption amount (%) at a relative humidity (RH) 75%, and R ₅₀ is the equilibrium moisture adsorption amount (R ₇₅ ) at a relative humidity (RH) 75% of 10 at the relative humidity 50%. It is the moisture adsorption amount (%) when kept for a day, and R ₉₀ is the relative humidity (RH) 75% and has the equilibrium moisture adsorption amount (R ₇₅ ).
Adsorption amount of water (R
₉₀ ) (%), 3. 3. The average particle size of the granules is in the range of 0.5 to 15 mm. It is preferably applied under the floor of the house. According to the present invention, there is also provided an underfloor humidity control method characterized in that the granular humidity control agent is arranged in layers under the floor. In the method of the present invention, a moisture-proof sheet may be laid under the floor, and a layer of a particulate humidity control agent may be provided on the moisture-proof sheet, or a sheet containing a particulate humidity control agent and at least the upper surface of which is breathable. Can be laid under the floor.

[0012]

[Embodiment of the Invention] [Operation] particulate regulating humectant of the present invention comprises a hydrated iron-containing aluminum oxide, and the following formula _{(1) xFe 2 O 3 ·} Al 2 O 3 · nH 2 O ‥ (1) In the formula, x has a molar ratio of 0.01 to 1.0, and n has a molar ratio of 0 <n ≦ 4. is there. Hydrated iron-containing aluminum oxide, as is clear from its name, is a complex hydrated oxide of aluminum containing iron, unlike a simple mixture of a hydrated oxide of iron and a hydrated oxide of aluminum, Large BET specific surface area and equilibrium adsorbed water content (RH7
5%).

In this hydrated iron-containing aluminum oxide, the inclusion of 0.01 mol or more of Fe ₂ O ₃ per 1 mol of alumina increases the specific surface area and the equilibrium adsorbed water content (RH).
75%) is important. See the example below. In the hydrated aluminum oxide formed from a basic aluminum salt sol containing no iron (Comparative Example 1), the BET specific surface area is also equal to the equilibrium adsorbed water content (RH 75%).
In the present invention, on the other hand, the BET specific surface area and the equilibrium adsorbed water content (RH 75%) are obtained by incorporating the above-mentioned amount of iron and coprecipitating it with alumina in the present invention.
Will be increased.

In the hydrated iron-containing aluminum oxide of the present invention, the BET specific surface area and the equilibrium adsorbed water content (RH75
%) Is rather increased over the hydrated oxide of aluminum, the fact that the hydrated oxide of iron is significantly smaller than the hydrated oxide of aluminum and the BET specific surface area and the equilibrium adsorbed water content (RH 75%) This is truly unexpected given the fact that it only shows. This fact has been found as a phenomenon, and the reason for this has not yet been clarified.However, under the condition that iron hydroxide is coprecipitated with the hydrated oxide of aluminum in the sol or gel state, it is rather a gel. It is believed that the complex hydrated oxide is formed in a state where the defects (a kind of network defects) of (1) are increased, which leads to increase of BET specific surface area, increase of mesopores and increase of pore volume.

On the other hand, in the hydrated iron-containing aluminum oxide, Fe ₂ exceeds 1.0 mol per mol of alumina.
When O ₃ is contained, the hydrated oxide of iron itself has a small BET specific surface area, so that the BET specific surface area and the equilibrium adsorbed water content (RH 75%) decrease, which is not preferable.

The hydrated iron-containing aluminum oxide of the present invention is
200 m^Two/ G or more, especially 250 m ^TwoBET over / g
The second characteristic is to have a specific surface area. This bet
Specific surface area is closely related to physical adsorption activity.
The hydrated iron-containing aluminum oxide used in the present invention contains
Exceptionally large BET specific surface area for iron compounds
It is something.

The hydrated iron-containing aluminum oxide used in the present invention has the third feature that the equilibrium moisture adsorption amount (R ₇₅ ) at a relative humidity (RH) of 75% is 20% or more, particularly 25% or more. As already pointed out, humidity control agents are required to effectively release the water retained under low humidity conditions, and exhibit high hygroscopicity under high humidity conditions. (R ₇₅ ) rather indicates the magnitude of the amount of adsorbed water in these intermediate regions. For example, the equilibrium moisture adsorption amount (R ₇₅ ) is 12 even for sepiolite which is conventionally said to have excellent humidity control performance.
%, It is understood that the hydrated iron-containing aluminum oxide of the present invention is excellent in the equilibrium water adsorption amount (R ₇₅ ).

The hydrated iron-containing aluminum oxide used in the present invention further has an average pore diameter in the range of 30 to 100 Å and a pore volume of 0.5 as determined by the BET method.
It also has the feature of being in the range of 0 to 1.20 ml / g. The pore diameter in the above range is a region called mesopore which is effective for adsorption and desorption of water, and has a considerably large pore volume as compared with sepiolite, and therefore, an excellent action as a humidity control agent can be obtained. .

The humidity control agent used in the present invention has a moisture release amount (RM) defined by the following formula (2) RM (%) = R ₇₅ -R ₅₀ (2) of 5% or more and the following formula. (3) AM (%) = R ₉₀ −R ₇₅ (3) The moisture absorption amount (AM) defined by (3) is 8% or more.
R ₇₅ is the equilibrium moisture adsorption amount (%) at a relative humidity (RH) 75%, and R ₅₀ is the equilibrium moisture adsorption amount (R ₇₅ ) at a relative humidity (RH) 75% of 10 at the relative humidity 50%. It is the moisture adsorption amount (%) when kept for a day, and R ₉₀ is the relative humidity (RH) 75% and has the equilibrium moisture adsorption amount (R ₇₅ ).
Adsorption amount of water (R
₉₀ ) (%). The moisture release amount (RM) is the moisture release amount (%) under low humidity conditions (RH 50%) based on the equilibrium moisture adsorption amount (R ₇₅ ) described above, while the moisture absorption amount (AM) is the equilibrium moisture content described above. It is the moisture absorption amount (%) under high humidity conditions (RH 90%) based on the moisture adsorption amount (R ₇₅ ), and the larger these values are, the better the humidity control property is. FIG. 1 of the accompanying drawings shows, for the hydrated iron-containing aluminum oxide particulate humidity conditioner and the sepiolite humidity conditioner of the present invention, a change in water content with time (3 weeks) at a relative humidity of 75%, and then a relative humidity of 50%.
And a relative humidity of 90%, which is a graph plotting a change in water content over time.
Equilibrium moisture adsorption amount (R ₇₅ ) is large, moisture release amount (RM%)
It is also found that the moisture absorption amount (AM%) is also excellent.

The granular humidity conditioner of the present invention is composed of the above-mentioned hydrated iron-containing aluminum oxide particles, and the average particle size thereof is preferably 0.5 to 15 mm, particularly preferably 1 to 10 mm. As the shape, not only a granular shape but also a spherical shape, a pellet shape, a columnar shape or the like can be used if necessary. By having a particle size in the above range, it is possible to improve workability in weighing, transportation, construction, etc. while preventing the powder from standing up and maintaining an excellent humidity control action.

The granular humidity control agent of the present invention is particularly preferably applied under the floor of a house. That is, Japanese houses, especially under the floor, are easily humid, and the humidity changes significantly with the changes of the four seasons.High humidity in the rainy season and summer and low humidity in the winter have a great influence on health and comfortable living. There is.

By arranging the granular humidity control agent of the present invention in layers under the floor, the humidity control under the floor can be easily performed, and dew condensation can be prevented. It is possible to prevent the occurrence of the above and to increase the useful life of the house. In the method of the present invention, a moisture-proof sheet may be laid under the floor, and a layer of the particulate humidity-controlling agent may be provided on the moisture-proof sheet, or the particulate humidity-controlling agent is blended and at least the upper surface is breathable. The seat can be laid under the floor.

Further, when the humidity under the floor is high, it is more effective to dry the underfloor by attaching a dehumidifying fan to the bottom of the floor so as to efficiently control the humidity under the floor. By rotating the dehumidifying fan, the granular humidity control agent of the present invention is dried, and the relative humidity can be maintained at about 40 to 60%,
The humidity under the floor is stable without drying, and the floor, pillars, etc. do not rot due to being moistened, and are not too dry, and are preferable for preservation of floors and pillars of wooden construction.

[Production Method of Hydrated Iron-Containing Aluminum Oxide] The hydrated iron-containing aluminum oxide of the present invention is an alkaline earth in which a salt produced by metathesis of a raw material solution containing a trivalent iron salt and an aluminum salt is water-soluble. P by metal hydroxide
Manufactured by neutralizing H to 4.0 to 4.5, filtering and washing the formed precipitate in the above pH range, redispersing the cake, and further removing acid radicals until the pH becomes 7 to 10. To be done.

The hydrated iron-containing aluminum oxide obtained above may be dried at 110 ° C. and then calcined at 200 to 1200 ° C., preferably 200 to 600 ° C.

As a typical example of the present invention, a raw material solution containing a trivalent iron salt and an aluminum salt (Fe ₂ O ₃ / Al ₂
O ₃ molar ratio 0.1 to 0.9) and 5 to 40% magnesium hydroxide slurry are simultaneously added in the range of pH 4.2 to 4.5. The reaction temperature at this time is room temperature to 90 ° C. After the reaction, the mixture is filtered and washed with water, the filter cake is further dispersed in water, and an alkali is added to adjust the pH. 40 ~
After aging at 100 ° C, the acid radical content is 4%, preferably 2%.
The hydrated iron-containing aluminum oxide of the present invention can be obtained by filtering and washing with water until the content of the iron-containing aluminum oxide is less than 50%. In addition to the simultaneous injection, the reaction is performed by adding an alkali to a raw material solution containing a trivalent iron salt and an aluminum salt to once precipitate hydrated iron oxide particles at pH 2.0 to 2.5, and then further increasing the pH to 4 The hydrated iron-containing aluminum oxide of the present invention can be obtained by adding an alkali so as to have a concentration of 0.2 to 4.5.

Particularly, as the solution containing the trivalent iron salt and aluminum salt as the raw materials, the waste acid produced when the acid clay is acid-treated is suitable. A typical composition of the spent acid is Al ₂ O ₃ 0.1. Having ~8% _Fe 2 _O 3 of 0.05 _~6% SO 3 0.5 _~30% composition. Specifically, magnesium hydroxide is added to this waste acid to neutralize it until the pH becomes 4.0 to 4.5, and the formed precipitate is filtered and washed in the above pH range, and the cake is redispersed to further Remove acid radicals until pH is 7-10

According to the method of the present invention, the iron salt has a pH of 2.0.
In the vicinity, precipitation of hydrated iron-containing oxide particles occurs before the aluminum salt. Next, the hydrated aluminum oxide precipitated at a pH of around 4.0 grows into boehmite gel, but it tends to become amorphous as the iron content increases. From this, it is considered that the trivalent hydrated iron oxide and hydrated aluminum oxide particles (boehmite gel) form a tight aggregate. The obtained hydrated iron-containing aluminum oxide was 10
The one dried or baked at 0 to 600 ° C., preferably 100 to 400 ° C. is used.

As the trivalent iron salt, sulfates, nitrates, hydrochlorides and the like can be used. Specific examples include ferric sulfate, ferric nitrate, and ferric chloride solutions, and ferric sulfate is preferably used.

As the aluminum salt, sulfates, nitrates, hydrochlorides and the like can be used. Specific examples include aluminum sulfate, basic aluminum sulfate, aluminum chloride, basic aluminum chloride and aluminum nitrate. Preferably, aluminum sulfate or basic aluminum sulfate is used.

Examples of the alkaline earth metal hydroxide used as the pH adjuster include magnesium hydroxide, calcium hydroxide, zinc hydroxide, barium hydroxide and the like. Magnesium hydroxide and calcium hydroxide are preferably used, and if necessary, caustic soda, caustic potash, sodium aluminate, sodium silicate and the like may be used.

[Use] The granular humidity conditioner of the present invention can be used for Japanese and Western chests, bookcases, cupboards, tables, in addition to humidity control under the floor.
Furniture such as desks and chairs, musical instruments such as pianos and violins, tableware, crafts such as various decorations, and other humidity regulators for maintaining the dimensional stability of wood used for Buddhist altars, altars, sacred tools, etc. Can be used in closets, libraries, museums, and above the ceiling. In addition, if necessary, a deodorant, an antibacterial agent, an inorganic adsorbent, an iodine compound having antibacterial properties such as povidone iodine,
Group II metal hydroxides and group IV metal phosphates or photoreactive semiconductors can be used in combination with a termite controlling agent (anticidal component).

(Inorganic adsorbent) As the inorganic adsorbent, for example, crystalline zinc silicate compound, aluminum-containing zinc phyllosilicate or a silicic acid complex thereof, magnesium phyllosilicate, magnesium-containing aluminum phyllosilicate, mesoporous silica. , Sepiolite, palygorskite,
Examples include activated carbon, bamboo charcoal, charcoal, natural zeolite, synthetic zeolite, antibacterial zeolite (supporting silver, copper, zinc, etc.), activated carbon fiber, silica gel, activated clay, alumina, vermiculite, diatomaceous earth, and the like. These inorganic adsorbents are used in an amount of 3 to 5 per 100 parts by weight of the granular humidity conditioner of the present invention.
It is preferable to use 0 parts by weight in combination.

(Anticidal component) Inorganic phosphorus-based, carbamate-based or pyrethrin-based insecticides are used in addition to inorganic chemicals such as zinc borate. Examples of the organophosphorus insecticide include oxime, chlorpyrifos, fenitrothion, pyridaphenthion, isofenphos, isoxathion, pyraclofos, and the like, and examples of the carbamate insecticide include bassa, propoxer, and the like. Examples of pyrethrin insecticides include allethrin, phthalthrin, resmethrin, permethrin, cypermethrin, decametrin, cyfluthrin, tralomethrin, cyhalomethrin, flutorinate and fluvalinate.

The method of holding the hydrated iron-containing aluminum oxide of the present invention between the sheets is not particularly limited. For example, the hydrated iron-containing aluminum oxide can be held by evenly sandwiching the hydrated iron-containing aluminum oxide of the present invention between two sheets and adhering or joining both sheets. The hydrated iron-containing aluminum oxide is held by bending one sheet, sandwiching the hydrated iron-containing aluminum oxide of the present invention between them, and joining the upper and lower sheets. The weight of the hydrated iron-containing aluminum oxide of the present invention to be held is 1000 g / m ² or less, preferably 10 to 850 g.
/ M ² , more preferably 15 to 600 g / m ² .

Further, the hydrated iron-containing aluminum oxide of the present invention is dispersed in natural fiber or synthetic fiber and water, and the resulting mixture is mixed to obtain a papermaking. Alternatively, the hydrated iron-containing aluminum oxide of the present invention may be dispersed in water to impregnate a sheet base material to obtain a sheet deodorant. Further, the above fibers may be used as a raw material to form a non-woven fabric by a method known per se. For example, a fiber can be mixed with the hydrated iron-containing aluminum oxide in the spinning process in advance, and then made into a non-woven fabric (Chemical Handbook [Applied Chemistry] Revised 3rd edition, 66th edition).
Page 0). The raw fibers used here include cotton, hemp,
Natural fibers such as pulp, cellulose (rayon, etc.), polyamide (nylon, etc.), polyester, polyvinyl chloride, polyvinylidene chloride, polyacrylonitrile (acrylic, etc.), polyolefin (polypropylene, polyethylene, etc.), Examples include chemical fibers such as polyurethane and polyvinyl alcohol (such as vinylon).

[0037]

The present invention will be described in the following examples, but the present invention is not limited to the following examples. Each test method was performed according to the following method.

(1) Chemical Analysis Ignition loss (Ig-loss), silicon dioxide (SiO ₂ ), aluminum oxide (Al ₂ O ₃ ), and sodium oxide (Na ₂ O) are analyzed according to JIS. M. It was measured according to 8855. In addition, Fe ₂
Atomic absorption method was used for O ₃ , CaO, MgO, and K ₂ O. The measurement sample is based on a dry product at 110 ° C.

(2) BET specific surface area and pore volume Sorptomatic Series manufactured by Carlo Erba Co.
S1900 was used, and it measured by the BET method.

(3) pH measurement According to JIS K 5101-26 (3) 3.1.

(4) Moisture Absorption / Desorption Measurement Test Method About 1 g of a sample was weighed in advance to 40 × 40 cm.
The sample is placed in a weighing bottle, and dried in an electric constant temperature dryer at 150 ° C. for 3 hours, and then cooled in a desiccator. Then, the weight of the sample is precisely weighed, put into a desiccator prepared to have a relative humidity of 75%, the weight increase is measured, and adsorption is carried out until the adsorption amount becomes equilibrium.
When the equilibrium is reached, the relative humidity is transferred to a desiccator of 50% and 90%, and the weight change after 10 days is RM = R ₇₅ -R
₅₀ , AM = R ₉₀ −R ₇₅ was determined. However, R _75,
R ₅₀ and R ₉₀ were calculated by the following calculations.

(5) Moisture adsorption amount The sample was dried in a dryer at 110 ° C. for 2 hours, and the weight change before and after the drying was measured and determined.

(Example 1) Dioctahedral smectite clay mineral raw material (chemical composition Ig-loss 6.1%, SiO ₂ 64.0%,
Al ₂ O ₃ 16.9%, Fe ₂ O ₃ 2.9%, CaO 0.8%, MgO 5.9%,) are crushed, kneaded and granulated to a diameter of 5 mm.
Was charged into the treatment tank. 28% by weight sulfuric acid aqueous solution 1
While pouring 50 Kg and circulating, the temperature was raised to 90 ° C., and the mixture was treated at that temperature for 5 hours. After the treatment was completed, the mother liquor was extracted to obtain Extract A. The composition of this extract is Al ₂ O ₃ 3.9%, Fe ₂ O ₃ 0.9
%, CaO 0.3%, MgO 1.9%, SO ₃ 20.7%. Then 300
Extraction liquid (Al ₂ O ₃ concentration of 1.0
%)), And after adjusting the temperature to 35 ° C., a 35% magnesium hydroxide slurry was added over about 3 hours until the pH became constant at 4.3. Approximately 7K of iron-aluminum hydrate cake that has been aged for 1 hour, suction-filtered, washed, and primarily neutralized
g (solid content concentration 30%) was obtained. Next, 8.0 kg of water was put into a 20 L stainless steel container, 5.0 kg of iron aluminum hydrate cake was added with stirring, and the temperature was raised to 60 ° C. after sufficiently dispersing. When the temperature reached 60 ° C, dilute sodium aluminate (Na ₂ O 16.0%, Al ₂ O ₃ 11.5%) was added.
Slowly add H so that it does not exceed 10 (neutralization / desulfurization treatment) When the pH finally stabilizes at 8.5, stop adding, and continue stirring / aging for 4 hours, suction filtration / washing, and hydration A cake of iron-containing aluminum oxide (AB) was obtained. Further, the cake was air-dried to have an average water content of 45%, extrusion-molded with an Eck pelleter, and dried overnight with a constant-temperature dryer set at 150 ° C. to obtain molded products of φ3 mm, 5 mm, and 10 mm. The properties of the obtained molded product are shown in Table 1. This φ3
FIG. 1 shows the moisture absorption / desorption measurement data of sepiolite for comparison with the mm product. Further, FIG. 2 shows a pore distribution diagram of the φ3 mm product.

(Example 2) φ3 mm prepared in Example 1
The molded product was fired at 400 ° C. and 600 ° C., the specific surface area was 331, 316 m ² / g, and the pore volume was 0.70.
ml / g, 0.67 ml / g, and the average pore diameter is 42.
It was 3Å and 42.4Å. The obtained molded product was used in Example 1.
As a result of performing a moisture absorption / absorption test in the same manner as in Example 1, the result was almost the same as in Example 1.

(Comparative Example 1) Reagent Aluminum sulfate (Wako Pure Chemical Industries, Ltd. first-grade reagent) was dissolved and adjusted to 1% as Al ₂ O ₃ , and the scale was adjusted to 1/5. A φ3 mm molded product was prepared. The properties are shown in Table 1.

(Example 3) Fe ₂ in the extract in Example 1
A predetermined amount of ferric sulfate (special grade reagent manufactured by Wako Pure Chemical Industries, Ltd.) is added so that the O ₃ content is tripled, and it is sufficiently dissolved over 5 hours.
Then, the same preparation as in Example 1 was carried out to obtain a molded product having a diameter of 3 mm. The properties are shown in Table 1.

(Examples 4 to 8) Cake AB obtained in Example 1 and the inorganic powders shown in Table 2 were mixed in a predetermined ratio on a dry matter basis, and a diameter of 3 mm was used in the same manner as in Example 1 using an Eck pelleter. Molded into.

(Embodiment 9) A model of a two-tatami wooden structure shown in FIG. 3 was prepared, and the floor was divided into two rooms (1 tatami mat each), and a plastic sheet was put on the soil at the bottom of the room A room. The 3 mm product prepared in Example 1 was crushed with a roll breaker 1 to
A sample having a size adjusted to 2 mm was filled in a thickness of 25 mm and the change in humidity was measured. On the other hand, the room B was filled with sepiolite, which was similarly sized, for comparison, and the humidity was measured in the same manner. The humidity was measured with ZR202G manufactured by YOKOGAWA. The results are shown in Fig. 4.

(Example 10) The chamber A was the same as the example 9, and the chamber B was compared with the humidity change without filling anything.
The results are shown in Fig. 5.

(Example 11) The room A was filled with the non-woven fabric of 20 cm x 12 cm x 4 cm prepared in Example 6 and laid on one side. On the other hand, in room B, 3 mm prepared in Example 8 was used.
The product was laid in the same manner as room A. Each of them was observed every month for 6 months, but no cockroaches or termites were observed.

(Example 12) 3 mm prepared in Example 1
The product was filled in a non-woven fabric of 20 cm x 12 cm x 4 cm, and the wet condition of the book was observed with and without the (mat) glass shelf with a glass door. As a result, none of the books felt damp when placed.

[0052]

[Table 1]

[0053]

[Table 2]

[0054]

EFFECT OF THE INVENTION BET containing a specific amount of ferric iron
A hydrated iron-containing aluminum oxide having a specific surface area of 200 m ² / g or more and an equilibrium moisture adsorption amount at RH 75% of 20% or more could be produced at low cost.
This iron-containing aluminum oxide is molded into a desired particle size, and has excellent performance as an underfloor humidity control agent, various dehumidifying agents, antibacterial agents and the like.

[Brief description of drawings]

FIG. 1 is an equilibrium moisture absorption / desorption curve diagram of Example 1, sepiolite.

FIG. 2 is a pore distribution diagram of Example 1 and 3 mm products.

FIG. 3 is a diagram showing an underfloor humidity control test apparatus.

FIG. 4 is a diagram showing the results of an underfloor humidity control test measurement in Example 9.

5 is a diagram showing the results of an underfloor humidity control test measurement in Example 10. FIG.

Continued front page    F-term (reference) 2E001 DB03 DH21 FA21 FA22 JA09                       MA01 MA06 NA03                 4D052 AA00 AA09 CA02 DA01 DB01                       GA04 GB03 GB13 GB17 GB18                       GB19 HA00 HA33 HA34 HB02                       HB07                 4G066 AA63A AA63B BA03 BA09                       BA16 BA20 BA23 BA25 BA26                       CA43 DA03 FA03 FA14 FA21                       FA26 GA06

Claims (8)

[Claims] During 1. A formula _{(1) xFe 2 O 3 ·} Al 2 O 3 · nH 2 O ‥ (1) formula, x is a number from 0.01 to 1.0 molar ratio, n represents moles The ratio is 0 <n ≦ 4, the BET specific surface area is 200 m ² / g or more, and the equilibrium moisture adsorption amount (R) at a relative humidity (RH) of 75%.
₇₅ ) A granular humidity conditioner characterized by comprising a hydrated iron-containing aluminum oxide granule having a content of 20% or more. 2. The average pore diameter is in the range of 30 to 100 angstroms, and the pore volume determined by the BET method is in the range of 0.50 to 1.20 ml / g. Granular moisturizer. 3. The moisture release amount (RM) defined by the following formula (2) RM (%) = R ₇₅ −R ₅₀ (2) is 5% or more and the following formula (3) AM (%). = R ₉₀ −R ₇₅ (3) The moisture absorption amount (AM) defined by (3) is 8% or more. In the formula, R ₇₅ is the equilibrium moisture adsorption amount (%) at a relative humidity (RH) 75%, R ₅₀ is related humidity (RH) 75
% Is the water adsorption amount (%) when it has an equilibrium water adsorption amount (R ₇₅ ) at a relative humidity of 50% for 10 days, and R ₉₀ is the equilibrium water adsorption amount (R ₇₅ ) at a relative humidity (RH) of 75% ( R ₇₅ ) having a relative humidity of 90% and held for 10 days at a moisture adsorption amount (R
₉₀ ) (%), The granular humidity control agent according to claim 1 or 2, characterized in that 4. The average particle diameter of the granular material is 0.5 to 15 mm.
The granular humidity control agent according to any one of claims 1 to 3, characterized in that 5. The granular humidity control agent according to claim 1, which is applied under the floor of a house. 6. An underfloor humidity control method, wherein the granular humidity control agent according to any one of claims 1 to 5 is arranged in layers under the floor. 7. The under-floor humidity control method according to claim 6, wherein a moisture-proof sheet is laid under the floor, and a layer of the particulate humidity controlling agent is provided on the moisture-proof sheet. 8. The underfloor humidity control method according to claim 6, wherein a sheet having a granular humidity control agent and at least an upper surface of which is breathable is laid under the floor.