JPH0576483B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a humidity control resin. More specifically, the present invention relates to a humidity control resin made by making a polymer of a specified (meth)acrylamide derivative insoluble in water. Conventional technology and its problems: Conventionally, humidity control methods for regulating the temperature in gases have mainly involved operating separate devices with two functions: dehumidification and humidification, and compared to temperature control. This requires extremely complicated equipment and work. Therefore, in closed spaces such as greenhouses, greenhouses, and buildings where there is little inflow of outside air, the problem of high humidity such as condensation that occurs due to changes in room temperature has not been fundamentally solved; This has become a problem in a variety of ways, including the outbreak of diseases due to the spread of electricity, and malfunctions of computers and other electronic equipment in offices within buildings. On the other hand, when cultivating crops in dry areas or soils with poor water retention, moisture in the soil becomes a problem.
Various humidifying agents such as soil water retention agents are being investigated. Recently, in response to the above-mentioned problems, there has been an idea to use hydrophilic resins with water absorption ability for humidity control, in addition to the conventional idea of air conditioning.
Various prototypes are being considered. However, in general, these resins have strong water absorption ability, so although they have strong dehumidifying ability, they lack the ability to adjust or humidify at a certain humidity, and are not sufficient for humidity control. However, such a humidity control method using resin has excellent advantages over conventional methods in various respects such as equipment costs, upkeep/maintenance, and installation location. Means for Solving the Problems: In view of the above points, the present inventors were investigating resins with humidity control ability, and found that they made a polymer of a specific (meth)acrylamide derivative insoluble in water. The present inventors have discovered that the resin has a moisture absorption ability that changes depending on the temperature, and has the property of releasing moisture when heated, and has extremely excellent properties as a humidity control resin, leading to the present invention. That is, the present invention is represented by the general formula () or the general formula () and the general formula

[Formula] (In the above formula, R ₁ represents a hydrogen atom or methyl group, R ₂ represents a hydrogen atom, methyl group, or ethyl group, and R ₃ represents a methyl group, ethyl group, or propyl group.) General formula

[Formula] (In the above formula, R ₁ is a hydrogen atom or a methyl group, A is (-
CH ₂ )— _o and n is 4 to 6 or (—CH ₂ ) ₂ —O(—
CH ₂ ) - represents ₂ . ) A humidity control resin made by insoluble in water a single or copolymer of N-alkyl- or N-alkylene-substituted (meth)acrylamide, or a copolymer with other copolymerizable monomers. Examples of monomers used in the present invention include N-n-propylacrylamide (cloud point of polymer).
32°C), N-n-propylmethacrylamide, N
- Isopropylacrylamide (polymer cloud point 29
°C), N-isopropylmethacrylamide, N-
Ethylacrylamide, N,N-diethylacrylamide, N-ethylmethacrylamide, N,N
-Dimethylacrylamide, N,N-dimethylmethacrylamide, N-acryloylpyrrolidine (polymer cloud point 51°C), N-methacryloylpyrrolidine, N-acryloylpiperidine, N-methacryloylpiperidine, N-acryloylmorpholine, etc. can. In addition, monomers that can be copolymerized with the above monomers include hydrophilic monomers, ionic monomers, lipophilic monomers, etc., and one or more of these monomers are applicable. can. Specifically, the hydrophilic monomers include, for example, acrylamide, methacrylamide, N-methylacrylamide, diacetone acrylamide, hydroxyethyl methacrylate,
Examples include hydroxyethyl acrylate, hydroxypropyl methacrylate, hydroxypropyl acrylate, various methoxypolyethylene glycol methacrylates, various methoxypolyethylene glycol acrylates, N-vinyl-2-pyrrolidone, and vinyl acetate, glycidyl methacrylate, etc. It can also be introduced by copolymerization and hydrolyzed to impart hydrophilicity. Examples of the ionic monomer include acrylic acid, methacrylic acid, vinylsulfonic acid, allylsulfonic acid, methallylsulfonic acid, styrenesulfonic acid, 2-acrylamido-2-phenylpropanesulfonic acid, and 2-acrylamide-2- Acids such as methyl-propanesulfonic acid and their salts, N,N-dimethylaminoethyl methacrylate, N,N-diethylaminoethyl methacrylate, N,N-dimethylaminoethyl acrylate, N,N-dimethylaminopropylmethacrylamide, N , N-dimethylaminopropylacrylamide, and salts thereof. It is also possible to introduce various acrylates, methacrylates, acrylamide, methacrylamide, acrylonitrile, etc. by copolymerization and hydrolyze them to impart ionicity. As a lipophilic monomer, for example, N-
n-butylacrylamide, N-n-butylmethacrylamide, N-tert.-butylmethacrylamide, N-tert.-butylmethacrylamide, N-n
-hexyl acrylamide, N-n-hexyl methacrylamide, N-n-octyl acrylamide, N-n-octyl methacrylamide, N-
N-alkyl (meth)acrylamide derivatives such as tert.-octylacrylamide, N-n-dodecyl acrylamide, N-n-dodecylmethacrylamide, N,N-diglycidyl acrylamide,
N,N-diglycidyl methacrylamide, N-
(4-glycidoxybutyl)acrylamide, N
-(4-glycidoxybutyl)methacrylamide,
N-(ω-glycidoxyalkyl)(meth)acrylamide derivatives such as N-(5-glycidoxypentyl)acrylamide, N-(6-glycidoxyhexyl)acrylamide, ethyl acrylate, methyl methacrylate, butyl methacrylate, (Meth)acrylate derivatives such as butyl acrylate, lauryl acrylate, 2-ethylhexyl methacrylate, glycidyl methacrylate, acrylonitrile, methacrylonitrile vinyl acetate, vinyl chloride, ethylene, propylene,
Examples include olefins such as butene, styrene, α-methylstyrene, butadiene, isoprene, and the like. Methods for making the monomer polymers mentioned above insolubilized in water include a method of making them insolubilized during polymerization and a method of making them insolubilized by treatment after polymerization. A method of copolymerizing a crosslinkable monomer having a double bond with the above-mentioned (meth)acrylamide derivative, a method of copolymerizing an N-alkoxymethyl (meth)acrylamide derivative, a method of copolymerizing a crosslinking monomer having a double bond of ) A method of copolymerizing with an acrylamide derivative, a method of polymerizing in bulk, a method of heat-treating the polymer, a method of integrating the polymer with a water-insoluble fibrous substance such as cellulose, or a method of copolymerizing with an acrylamide derivative, or a method of copolymerizing with an acrylamide derivative, If amino groups, etc. are present, a method of reacting them with a polyfunctional compound such as epichlorohydrin to crosslink and make them insolubilized, and a method of making them insolubilized, as well as substituents having active hydrogen such as carboxy groups, sulfonic acid groups, hydroxyl groups, etc. Copolymerization with a substituted monomer or a method of forming a complex with a polymer substituted with these substituents to make it insolubilized can be employed. More specifically, in the first method, as a crosslinking monomer, for example, N,N'-methylenebisacrylamide, N,N-diallylacrylamide, triacryl formal, N,N-diacrylolimide, N,N-dimethacryloyl Imide, ethylene glycol acrylate, ethylene glycol dimethacrylate, various polyethylene glycol diacrylates, various polyethylene glycol dimethacrylates, propylene glycol diacrylate, propylene glycol dimethacrylate, various polypropylene glycol diacrylates, various polypropylene glycol dimethacrylates, 1,3-butylene Glycol diacrylate, 1,3-butylene glycol dimethacrylate, 1,4-butylene glycol dimethacrylate, glycerol dimethacrylate, neopentyl glycol dimethacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, trimethylolethane trimethacrylate, Trimethylolethane triacrylate, tetramethylolmethanetetramethacrylate, tetramethylolmethane triacrylate, divinylbenzene, dial rifthalate, etc. can be used. N- in the second method
Alkoxymethyl (meth)acrylamide derivatives also include N-hydroxymethyl (meth)acrylamide, such as N-methylol (meth)acrylamide.
Acrylamide, N-methoxymethyl (meth)acrylamide, N-ethoxymethyl (meth)acrylamide, N-n-butoxymethyl (meth)acrylamide, N-tert.-butoxymethyl (meth)acrylamide, and the like can be used. The ratio of the lipophilic monomer to the (meth)acrylamide derivative having unsafe properties in the third method varies depending on the combination of the (meth)acrylamide derivative and the lipophilic monomer, and cannot be definitively determined, but in general is 1% or more, preferably 3%
That's all. The fourth method of bulk polymerization is to directly polymerize without diluting with a solvent to obtain a polymer block, or to polymerize in monomer drops while suspending in a solvent to obtain a particulate polymer. methods etc. can be adopted. In the fifth method, which heat-treats polymers, the heating conditions vary depending on the polymer and are not uniform, but generally 60
The polymer obtained by bulk polymerization, suspension polymerization, solution polymerization, etc. is heat-treated at a temperature of ~250°C, preferably 80~200°C. At this time, in the solution polymerization, drying or solvent distillation and heat treatment may be performed simultaneously.
The sixth method of integrating with fibrous materials, etc. is to use water-insoluble fibrous materials such as fibers such as cellulose, nylon, polyester, acrylic, or nonwoven fabrics made of polypropylene, ethylene-propylene copolymers, etc. A method of impregnating or graft polymerizing the above-mentioned (meth)acrylamide derivative onto a water-insoluble porous inorganic material such as silica, alumina, or zeolite, or a method of impregnating the material with a polymer can be employed. In the seventh method, in which a polyfunctional compound such as epichlorohydrin is reacted to crosslink and insolubilize, it is necessary to introduce a hydroxyl group or an amino group into the polymer in advance. Amino groups can be easily introduced by copolymerization, but in the case of hydroxyl groups, they can be introduced by copolymerization with hydroxyethyl methacrylate, isopropenylphenol, etc., or by copolymerization with vinyl acetate, glycidyl methacrylate, etc., and then introduced with a basic substance. Another method is to introduce hydroxyl groups by saponification. Next, the above-mentioned polymer and a polyfunctional compound such as epichlorohydrin are reacted in the presence of a basic substance to crosslink and insolubilize the polymer. At that time, when the aqueous solution is insolubilized as it is, it becomes agar-like, and it is put into practical use by crushing it. Further, when an aqueous solution is dispersed in oil to make it insolubilized, it becomes a granular gel. The eighth method is copolymerization with the above-mentioned monomers having active hydrogen, complexing with copolymers of these monomers, replacing active hydrogen in the copolymer with ammonium ions, etc., and first mixing. This is a method in which a complex is formed by adding an acid to activate the active hydrogen and make it insolubilized. Each of the eight methods described above may be used alone or in combination. In general, more effective results can be obtained when used together. More specific polymerization methods that can be adopted in producing the humidity control resin of the present invention according to the above method include, for example, (1) polymerizing the monomer as it is without diluting it with a solvent to form a polymer block; (2) A method of obtaining a polymer by polymerizing in a solvent and drying after polymerization or precipitating the polymer in a poor solvent; (3)
Method for obtaining particulate polymers by suspension polymerization, (4)
A method of obtaining a polymer latex by emulsion polymerization, (5) a method of integrating a polymer by impregnating a water-insoluble fibrous material or porous inorganic material with a polymer solution or graft polymerization, etc. I can do it. At this time, the polymerization can be initiated by heating alone, but better results are usually obtained by using a polymerization initiator. The polymerization initiator is not limited as long as it has the ability to initiate radical polymerization, and includes, for example, inorganic peroxides, organic peroxides, combinations of these peroxides and reducing agents, and azo compounds.
Specifically, there are ammonium persulfate, potassium persulfate, hydrogen peroxide, tert-butyl peroxide, benzoyl peroxide, cumene hydroxy peroxide, tert-butyl peroxy-2-ethylhexanoate, butyl perbenzoate, etc. Reducing agents used in combination with these include sulfites, hydrogen sulfites, salts with low ionic valences such as iron, copper, and cobalt, organic amines such as aniline, and aldoses.
Examples include reducing sugars such as ketose. Examples of azo compounds include azobisisobutyronitrile,
2,2'-azobis-2-amidinopropane hydrochloride, 2,2'-azobis-2,4-dimethylvaleronitrile, 4,4'-azobis-4-cyanovaleric acid, etc. can be used. It is also possible to use two or more of the above polymerization initiators in combination. In this case, the amount of the polymerization initiator to be added is sufficient to be within the normally adopted quantitative range, for example, from 0.01 to 5% by weight, preferably from 0.05 to 2% by weight, based on the monomer. Among the polymers obtained in this way, those in block form or those obtained by distilling off the solvent can be crushed into powder, or melted into granules,
Molded into flakes, fibers or films,
The particulate polymer can be used as it is, and the latex polymer can be provided as a humidity control resin by impregnating and coating fibrous materials such as cloth and paper, or by forming it into a film. Although various forms of humidity control resin can be produced by the above-mentioned method, the form varies depending on how the humidity control resin is used, and cannot be uniformly defined. However, these resins are generally used in powder or granule form in many cases. The powdered product can be obtained by various methods such as gel polymerization in an aqueous solution as described above, followed by drying and pulverization. On the other hand, granular products are generally easily produced by suspension polymerization, but since the acrylamide or methacrylamide derivatives used in the present invention are generally highly water-soluble, suspension polymerization is not suitable. Reverse-phase suspension polymerization in which monomers or their aqueous solutions are dispersed in oil, salting-out suspension polymerization in which a large amount of electrolyte, etc. is dissolved in an aqueous solution to suppress the solubility of the monomers, and further polymerization. A method such as precipitation suspension polymerization, in which polymerization is performed at a high temperature above the cloud point to precipitate the polymer, is employed. Furthermore, porous inorganic particles such as silica, alumina, and zeolite, whose surfaces are impregnated with a polymer solution or integrated with a polymer by a method such as graft polymerization, may also be used. Furthermore, at that time, a tertiary substance that is compatible with the monomer but not compatible with the polymer is added.
It is also possible to produce a porous resin by adding components. The humidity control resin produced as described above is in a solid state, and absorbs and retains water when it comes into contact with gaseous water, such as moisture in the atmosphere, and absorbs or releases water depending on the humidity and temperature of the outside air. You can do this and repeat the process. Generally, the amount of moisture absorbed at low temperatures is greater than the amount of moisture absorbed at high temperatures, so it is possible to act as a dehumidifier at low temperatures and as a humidifier at high temperatures, reducing changes in relative humidity due to temperature changes, and It has the function of maintaining constant humidity. The amount of moisture absorbed by the resin, that is, the amount of water absorbed, changes depending on the composition of the resin and the temperature and humidity of the atmosphere. Regarding the resin composition, in the case of a copolymer with a lipophilic monomer among the copolymerizable monomers described above, as the ratio thereof increases, the amount of water absorbed decreases, while the mechanical strength of the resin increases. Furthermore, in the case of a copolymer with a hydrophilic or ionic monomer, as the ratio increases, the water absorption itself increases, but the change in water absorption due to temperature decreases, and the mechanical strength also decreases. As mentioned above, the amount of water absorbed varies depending on the resin composition, but at room temperature (25℃) it can absorb about 2 to 100 times its own weight, and when the temperature is lowered, the amount of water absorbed can be increased. . Therefore, since the humidity control resin of the present invention can easily control the amount of moisture absorbed, it is possible to control the humidity of a large volume of gas with a small amount of the humidity control resin. A specific method for controlling humidity using the humidity controlling resin of the present invention is to simply bring the resin into contact with the gas to be controlled. There are no particular restrictions on the shape of the resin, including powder,
Depending on the purpose, particles, flakes, fibers, films, or composites thereof with other fiber materials can be used. At this time, heating or dehumidification can be performed depending on the temperature and humidity of the atmosphere, and this can be repeated as many times as the atmosphere changes. More specific humidity control methods include (1) placing the resin in an atmosphere and relying on the humidity control function of the resin to control the humidity; and (2) controlling the temperature of the resin. There are two main methods that can be used to control humidity. When using powdered, granular, or flake resin, method (1) uses fixed bed, fluidized bed,
The resin and gas may be brought into contact using a moving bed or the like. Further, in the method (2), the above-described method may be adopted so that the resin can be heated or cooled by a method such as external heat exchange or internal heat exchange. On the other hand, resins in the form of fibers, films, or composites of these with fiber materials or films,
It can be glued to a wall like wallpaper, or hung indoors like an awning or curtain, as long as it can come into sufficient contact with moisture in the gas. If method (2) is adopted for this form,
Although it is not as simple as method (1), for example, there is a method of processing the resin described above into a tube shape and heating and cooling it by flowing steam, water, temperature-controlled gas, etc., or the method described above. When resin is used on walls as curtains, awnings, wallpaper, etc., a method of heating and cooling from the outside is adopted. In addition, by appropriately selecting the composition and amount of resin used, it is possible to set the humidity in the gas to be high or low. When using a strong resin, it can be set to a low humidity range. Specific applications include humidity control during crop cultivation in closed spaces such as greenhouses, plastic greenhouses, and greenhouse horticulture using vinyl film, humidity control in rooms where computers and other electronic equipment sensitive to high humidity are installed, and general housing. Examples include preventing dew condensation on walls and windows, and controlling humidity within the soil. Function: As described above, the humidity control resin of the present invention does not primarily use phase changes such as evaporation and condensation, so humidity control is possible at low cost and does not necessarily require large-scale use. No equipment is required and it can be installed at any location. Second, since the amount of moisture absorbed increases as the temperature decreases, it is possible to easily dehumidify at low temperatures, and it is possible to reduce the range of changes in relative humidity that occur with changes in temperature. Thirdly, since the amount of water retained in the resin can be reversibly set depending on the temperature, there is an effect that the water content in the gas can be controlled based on the temperature. The present invention will be further explained below with reference to Examples. Example 1 507.5 g of N-propylacrylamide and N,
2.6g of N'-methylenebisacrylamide and water
An aqueous solution of N-propylacrylamide containing 0.5 wt% N,N'-methylenebisacrylamide dissolved in 1170 g was prepared. After cooling the aqueous solution to 10°C, transfer it to a stainless steel brewer bottle No. 2,
Nitrogen gas was bubbled for 1 hour using a ball filter at a flow rate of 1/min. Next, a solution prepared by dissolving 2.55 g of ammonium persulfate in 10 g of water and a solution prepared by dissolving 1.16 g of sodium bisulfite in 10 g of water were added simultaneously to the aqueous solution, and the aqueous solution was polymerized adiabatically. The obtained gel was shredded and dried, and then further crushed to collect a fraction of 20 to 100 meshes, which was used as a sample. 0.5g of the sample powder was heated to 30°C.
When it was added to a 500ml plastic bag containing air with a relative humidity of 67% and left for 20 minutes, the relative humidity of the air inside the plastic bag became 34%. When this bag was further cooled by contacting it with the surface of ice water, the relative humidity decreased to 22%, and the temperature inside the plastic bag at that time was 16°C. When this plastic bag was left at room temperature, the relative humidity inside the bag reached 32%. Example 2 The sample powder obtained in Example 1 was heated at 10°C in distilled water.
10g of water-retaining gel swollen with water (moisture content 9.4g)
was placed in a plastic bag with an internal volume of 500ml and sealed. As a result of measuring the relative humidity while changing the temperature, it was 87 at 30℃.
%, 37% at 25℃, 87% again at 30℃, and then 40℃
So we got a value of 98%. Example 3 A sample powder was obtained in the same manner as in Example 1 using a 30% aqueous solution of N-acryloylpyrrolidine containing 0.5 wt% of N,N'-methylenebisacrylamide. The relative humidity inside the greenhouse was measured using a domestic vinyl greenhouse with an internal volume of 195 mm, equipped with a device for forced air circulation through a temperature-controllable filling tube filled with 8.5 g of the sample powder.
When the air in the greenhouse was not forced to circulate, the temperature in the greenhouse was 26.5°C and the relative humidity was 72%. When the filled tube was cooled to 10℃ and the air inside the greenhouse was forced to circulate through the filled tube at a circulation rate of 9.5/min, the temperature inside the greenhouse remained at 26.5℃, but the relative humidity was
It dropped to 30%. Next, when the temperature of the filled tube was heated to 50℃, the temperature inside the greenhouse was 27℃ and the relative humidity was
It was 64%. Example 4 Using the same household vinyl greenhouse as in Example 3, 1.5 kg of moist soil was placed in the greenhouse and the relative humidity inside the greenhouse was measured in the same manner as in Example 3. When controlled to , the temperature inside the greenhouse is 25.5
℃ and relative humidity was 75%. Then fill the tube with 10
When the tube was cooled to 25°C, the temperature inside the greenhouse was 25°C and the relative humidity was 63%. When the filled tube was heated again to 50°C, the temperature inside the greenhouse was 25.5°C and the relative humidity was 93%.
It was hot. During this measurement, the soil was kept moist. Example 5 The entire apparatus used in Example 4 was placed in a constant temperature room, and changes in relative humidity inside the greenhouse were measured when the outside temperature was changed. At this time, the temperature of the filling tube was kept at the same temperature as the outside temperature without being separately controlled. When the outside temperature was 33°C, the temperature inside the greenhouse was also 33°C, and the relative humidity was 57%. Then, when the outside temperature was lowered to 15°C, the temperature inside the greenhouse was 15.5°C and the relative humidity was 92%. During this measurement, the soil kept in a moist state, and no dew condensation was observed on the inner walls of the greenhouse. Comparative Example 1 The filling tube was removed from the apparatus of Example 4, and the change in relative humidity in the greenhouse was measured in the same manner as in Example 5. When the outside temperature was 34°C, the temperature inside the greenhouse was 33.5°C, and the relative humidity was 69%. Next, when the outside temperature was gradually lowered, condensation began to form on the inner walls of the greenhouse at an outside temperature of 20°C, and at this time the temperature inside the greenhouse was 24°C.
Relative humidity was 76%. Further lower the outside temperature
When the temperature reached 16℃, the temperature inside the greenhouse was 16.5℃, the relative humidity was 99%, and condensation had formed all over the inside walls of the greenhouse, and the condensed moisture was dripping down the inside walls of the greenhouse. . Example 6 Polymerization was carried out in the same manner as in Example 1 using a 30% aqueous solution of N-acryloylpyrrolidine. A polyester nonwoven fabric (50 cm x 60 cm, 9.7 g) was immersed in a solution of the polymer in methanol, and then the nonwoven fabric was vacuum dried. The amount of N-acryloylpyrrolidine polymer impregnated into the nonwoven fabric was 5.4 g.
The filling tube was removed from the apparatus of Example 4, and the polyester nonwoven fabric impregnated with N-acryloylpyrrolidine was suspended in the greenhouse.
Changes in relative humidity inside the greenhouse were measured using the same method. When the outside temperature was 22°C, the temperature inside the greenhouse was also 22°C, and the relative humidity was 89%. When the outside temperature is 36°C, the temperature inside the greenhouse is 35.5°C, and the relative humidity is 58°C.
%. Next, when the outside temperature was set to 15°C, the temperature inside the greenhouse became 15.5°C and the relative humidity was 95%. During this measurement, the soil kept in a moist state, and no dew condensation was observed on the inner walls of the greenhouse. Example 7 30% of N-isopropylacrylamide with 0.5wt% N,N'-methylenebisacrylamide
A sample powder was obtained in the same manner as in Example 1 using an aqueous solution. The sample powder was placed in distilled water.
10g of water retention gel swollen at 10℃ (moisture content 9.6
g) was left in a plastic bag with an internal volume of 500 ml and sealed.
As a result of measuring the relative humidity by changing the temperature, it was 85 at 30℃.
%, 33% at 20℃, 86% again at 30℃, and then 50℃
So we got a value of 95%. Example 8 30% of N,N-diethylacrylamide with 0.5wt% N,N'-methylenebisacrylamide
The N,N-dimethylformamide solution was transferred to a dehydrator bottle, and the solution was purged with nitrogen. Then, 1.5% of azobisisobutyronitrile was added at 30°C, and polymerization was carried out adiabatically. The resulting gel was cut into pieces, dried at 120°C, and further ground to collect 20 to 100 mesh fractions, which were used as samples. 10g of water-retaining gel (water content:
8.0g) was left in a plastic bag with an internal volume of 500ml and sealed. As a result of measuring the relative humidity by changing the temperature, it was 30℃
76% at 20°C, 41% at 20°C, 75% again at 30°C, and further
At 50℃, a value of 82% was obtained. Example 9 A sample powder was obtained in the same manner as in Example 1 using a 30% aqueous solution of N-acryloylmorpholine containing 0.5 wt% of N,N'-methylenebisacrylamide. The sample powder was incubated in distilled water at 10°C.
10g of water-retaining gel swollen with water (moisture content 9.3g)
was placed in a plastic bag with an internal volume of 500ml and sealed. As a result of measuring the relative humidity by changing the temperature, it was 86 at 30℃.
%, 35% at 20℃, 87% again at 30℃, and then 50℃
We obtained a value of 94%.

Claims (1)

[Claims] 1 [Formula] represented by general formula () or general formula () (In the above formula, R ₁ is a hydrogen atom or a methyl group, R ₂ is a hydrogen atom, a methyl group or an ethyl group, and R ₃ is (Represents a methyl group, ethyl group or propyl group.) [Formula] (In the above formula, R ₁ is a hydrogen atom or a methyl group, and A is (-
OH ₂ ) _o -- and n is 4 to 6 or (-OH ₂ ) ₂ --O(
―
OH ₂ ) ₂ -- represents. ) A humidity control resin made by insolubilizing a radical alone or a copolymer of N-alkyl or N-alkylene-substituted (meth)acrylamide, or a radical copolymer with other copolymerizable monomers in water. A method for controlling the humidity of a gas, characterized by humidifying and dehumidifying the gas by bringing it into contact with the gas.