JPH0576484B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to resins for retaining and releasing useful substances. More specifically, the present invention relates to a resin for retaining and releasing useful substances, which is made by making a polymer of a specific (meth)acrylamide derivative insoluble in water. Conventional technology and its problems: In recent years, various types of sustained-release drugs have been developed based on the idea of gradually releasing and acting on useful substances when used in bulk, with the aim of reducing the side effects of drugs and agricultural chemicals, and prolonging their efficacy over a long period of time. Methods are being considered. Currently, many attempts are being made for this purpose, but they can be roughly divided into two directions. One is the idea of polymerizing these useful substances, and specifically, introducing these substances into the side chains of polymers and gradually releasing them through decomposition reactions such as hydrolysis. It is. The other method is to coat these useful substances with a polymer compound that can be decomposed in living organisms, such as polylactic acid, and release them when the polymer compound is decomposed. However, both methods have problems, such as polymerization and regeneration in the former, while coating methods in the latter. Means for solving the problem: In view of the above points, the present inventors further focused on the fact that these useful substances are used in the presence of water,
As a result of intensive investigation into the retention and release of these useful substances by aqueous gels, we found that a specific (meth)acrylamide derivative polymer made insoluble in water has extremely specific water and useful substance retention properties. We have found that this is extremely convenient for retaining and releasing useful substances, leading to the present invention. That is, the present invention relates to the general formula () or the general formula represented by 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 )—O(—CH ₂
) - represents ₂ . ) This is a concentration-adjusting 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. Specific N-alkyl or N- in the present invention
Specifically, the alkylene-substituted (meth)acrylamide includes, for example, N-n-propyl methacrylamide (polymer cloud point: 32°C), N-n-propyl methacrylamide,
N-isopropylacrylamide (cloud point of polymer
29℃), 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. I can do it. In addition, monomers that can be copolymerized with the above monomers include hydrophilic monomers, ionic monomers, hydrophilic monomers, etc., and one or more of these monomers are applicable. can. Specifically, as a hydrophilic monomer,
For example, acrylamide, methacrylamide, N
- Methylacrylamide, diacetone acrylamide, hydroxyethyl methacrylate, hydroxyethyl acrylate, hydroxypropyl methacrylate, hydroxypropyl acrylate, various methoxypolyethylene glycol methacrylates, various methoxypolyethylene glycol acrylates, N-vinyl-2-pyrrolidone, etc. You can also use vinyl acetate,
Glycidyl methacrylate or the like 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. Examples of lipophilic monomers include N-n-butylacrylamide, N-butylmethacrylamide, N-tert.-butylacrylamide, N-
tert.-butyl methacrylamide, N-n-hexyl acrylamide, N-n-hexyl methacrylamide, N-n-octylacrylamide, N-
N-alkyl (meth)acrylamide derivatives such as n-octylmethacrylamide, N-tert.-octylacrylamide, N-n-dodecylmethacrylamide, N-n-dodecylmethacrylamide,
N,N-diglycidyl acrylamide, N,N-
Diglycidyl methacrylamide, N-(4-glycidoxybutyl)acrylamide, N-(4-glycidoxybutyl)methacrylamide, N-(5
-glycidoxypentyl)acrylamide, N-
N-(ω-glycidoxyalkyl)(meth)acrylamide derivatives such as (6-glycidoxyhexyl)acrylamide, ethyl acrylate, methyl methacrylate, butyl methacrylate, butyl acrylate, lauryl acrylate, 2-ethylhexyl methacrylate, glycidyl methacrylate, etc. (meth)acrylate derivatives of, acrylonitrile, methacrylonitrile, vinyl acetate,
Vinyl chloride, olefins such as ethylene, propylene, butene, styrene, α-methylstyrene,
Examples include butadiene, isoprene, etc. Next, methods for making the above-mentioned monomer polymer insolubilized in water include a method of making it insolubilized during polymerization and a method of making it insolubilized by treatment after polymerization. A crosslinking monomer having more than 1 double bond and the above (meth)
A method of copolymerizing with an acrylamide derivative, a method of copolymerizing with an N-alkoxymethyl (meth)acrylamide derivative, a method of copolymerizing with a (meth)acrylamide derivative by increasing the ratio of the above-mentioned lipophilic monomer, a method of polymerizing in bulk, A method of heat treating a polymer, a method of integrating a polymer with a water-insoluble fibrous substance such as cellulose, or a method of combining a hydroxyl group or an amino group with epichlorohydrin etc. if the polymer contains hydroxyl groups or amino groups. A method of crosslinking and insolubilizing a polyfunctional compound by reacting it, and copolymerization with a monomer substituted with a substituent having an active hydrogen such as a carboxy group, a sulfonic acid group, a hydroxyl group, etc. A method of forming a complex with a substituted polymer and making it insolubilized can be adopted. 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. The N-alkoxymethyl (meth)acrylamide derivatives in the second method also include N-hydroxymethyl (meth)acrylamide, such as N-methylol (meth)acrylamide, N-methoxymethyl (meth)acrylamide, N-ethoxymethyl (Meth)acrylamide, N-n-butoxymethyl (meth)acrylamide, N-tert.-butoxymethyl (meth)acrylamide, etc. 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% or more. At this time, as the copolymerization method, any of random copolymerization, block copolymerization, and graft copolymerization can be adopted. As the fourth method of bulk polymerization, there is a method of diluting with a solvent. Amino groups can be easily introduced by copolymerization, but in the case of hydroxyl groups, hydroxyemyl methacrylate,
There is also a method in which hydroxyl groups are introduced by copolymerization with isopropenylphenol or the like, or by copolymerization with vinyl acetate, glycidyl methacrylate, etc., followed by saponification with a basic substance. 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,
This is a method in which the active hydrogen in the copolymer is replaced with ammonium ions or the like, mixed first, and then an acid is added to activate the active hydrogen to form a complex 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 resin of the present invention according to the above method include, for example, (1) producing a polymer block by directly polymerizing the monomer without diluting it with a solvent; Method,
(2) A method of obtaining a polymer by polymerizing in a solvent and drying after the polymerization or precipitating the polymer in a poor solvent; (3) A method of obtaining a particulate polymer by suspension polymerization; (4) A method of obtaining a particulate polymer by emulsion polymerization. (5) A method in which a water-insoluble fibrous or porous material is impregnated with a polymer solution or graft polymerization is used to integrate the polymer. 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, ammonium persulfate, potassium persulfate, hydrogen peroxide, tert.-butyl peroxide, benzoyl peroxide, cumene hydroxy peroxide, tert.-butyl peroxy-2-ethylhexanoate, butyl perbenzoate, etc. Reducing agents that can be combined with these include sulfites, hydrogen sulfites, salts with low ionic valences such as iron, copper, and cobalt, organic amines such as aniline, and reducing sugars such as aldoses and ketoses. be able to. Examples of azo compounds include azobisisobutyronitrile, 2,2'-azobis-2-
Amidinopropane hydrochloride, 2,2'-azobis-
2,4-dimethylvaleronitrile, 4,4'-azobis-4-cyanovaleic 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,
Particulate polymers can be used as such, and latex polymers can be impregnated and coated on fibrous materials such as cloth and paper, or formed into films to provide resins for the retention and release of useful substances. Although various forms of resin can be produced by the above-described method, the form depends on how the 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 the N-
Since alkyl- or N-alkylene-substituted (meth)acrylamides are generally highly water-soluble, suspension polymerization methods include reverse-phase suspension polymerization in which monomers or their aqueous solutions are dispersed in oil, and inverse-phase suspension polymerization in which monomers or their aqueous solutions are dispersed in oil. Methods such as salting-out suspension polymerization, which is performed by dissolving monomers to suppress the solubility of monomers, and precipitation suspension polymerization, which is performed at high temperatures above the clouding point of the polymer to precipitate the polymer, are adopted. be done. Furthermore, porous particles such as silica, alumina, and zeolite which are integrated with a polymer by impregnating the surface with a polymer solution or by graft polymerization can also be used. Furthermore, it is also possible to produce a porous resin by adding a third component that is compatible with the monomer but not compatible with the polymer. The resin for retaining and releasing useful substances produced as described above has two advantageous properties. 1
One has the property of absorbing and retaining water upon contact with an aqueous solution, shrinking and releasing water even in the presence of a large excess of water by heating, and the process of absorbing, retaining, and releasing water can be repeated. . Further, the amount of water absorbed by the agent changes depending on the composition of the resin, temperature, composition of the aqueous solution, etc. Regarding the resin composition, in a copolymer with a lipophilic monomer among the copolymerizable monomers mentioned above, as the ratio increases, the water absorption decreases, while the mechanical strength of the resin increases. Become. Furthermore, in the case of a copolymer with a lipophilic 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. . When low-molecular substances such as inorganic salts, organic salts, and water-soluble organic substances are dissolved in the aqueous solution, the aqueous solution containing these substances can be incorporated into the resin as is. When inorganic salts are dissolved, the amount of water absorbed by conventional water-absorbing resins decreases rapidly. The water absorption amount decreased to 1/17 in water and in 1N aqueous sodium chloride solution. On the other hand, in the case of the resin for retaining and releasing useful substances of the present invention, the rate of decrease was around 10%, and it can be concluded that the effect of coexisting salts on the water absorption amount is small. Furthermore, depending on the type of coexisting salt, for example, calcium chloride has been found to increase the amount of water absorbed. In addition, when a polymer compound is dissolved, it is not incorporated into the resin but is eliminated, and the resin has molecular weight fractionation ability. The molecular weight fraction varies depending on the composition and temperature of the resin, so it cannot be stated uniformly, but for example, in a resin made by crosslinking polyN-acryloylpyrrolidine with methylenebisacrylamide at around room temperature, for polyethylene glycol, it is 1000% To the order of
On the other hand, dextran and protein exist on the order of 10,000. Furthermore, as a matter of course, the molecular weight fraction is not uniquely determined, but has a distribution. The second property is that the resin of the present invention has a compound substituted with a group having active hydrogen such as a carboxy group, a hydroxyl group, a sulfonic acid group, a phosphoric acid group, a mercapto group, and a substituted hydrophobic residue. It can exert intermolecular forces such as hydrogen bonds and hydrophobic bonds with other compounds, forming a complex. This intermolecular force can be strengthened by heating and making the resin hydrophobic. In either case, retention and release can be controlled by temperature. The resin of the present invention having the above-mentioned properties is used to retain and release useful substances, but the embodiment thereof varies depending on the type of useful substance. For example, in the case of water-soluble low-molecular-weight compounds represented by fertilizers such as ammonium sulfate, urea, and ammonium phosphorus, an easy way to retain them is to bring the resin into contact with the aqueous solution and incorporate the components into the resin together with the aqueous solution. Bye. The concentration of the aqueous solution at that time may be below the saturation solubility. In addition, as a release method, when contact with water occurs due to rainwater or the like, the components in the resin are eluted as the water diffuses into the resin. Furthermore, if there is no contact with water, the resin may be contracted and released by heating. Furthermore, if there is contact with water, it is more convenient to simply mix the compound powder and the resin. That is, when water accumulates around it, such as from rainwater, the powder dissolves therein, while the resin swells with the water, and as a result, those compounds are retained in the resin. Alternatively, in solution polymerization, one of the production methods described above, polymerization is carried out in a solvent that does not dissolve the compound to be retained, and the compound is added either before or after polymerization, and the solvent is distilled from the solution. These compounds can also be retained in the resin by heat treatment. Release naturally occurs gradually upon contact with water. On the other hand, compounds substituted with active hydrogen-containing groups such as carboxy groups, hydroxyl groups, sulfonic acid groups, phosphoric acid groups, and mercapto groups that can exert intermolecular forces such as hydrogen bonds or hydrophobic bonds with the resin, and hydrophobic Compounds with substituted functional residues can be easily retained and released by controlling the temperature. Specific examples of the above-mentioned compounds include proteins, oxygen, amino acids, nucleic acids, polysaccharides, foods, antibiotics, various physiologically active substances, phenols, alcohols, aliphatic carboxylic acids, aromatic carboxylic acids, and heterocyclic carboxylic acids. Acids, aliphatic sulfonic acids,
Examples include aromatic sulfonic acids, mono- and diphosphoric acid esters, polyphosphoric acid esters such as ADP and ATP, surfactants, aromatic compounds, dyes, and fragrances. That is, it can be held at a high temperature and released at a low temperature. The high temperature is the temperature below the thermal denaturation temperature of the substance and the point at which it exhibits its maximum retention capacity, which varies depending on the resin and the compound to be retained, but generally speaking
The temperature ranges from 10 to 100°C. On the other hand, the low temperature is determined by the rate at which it is released, and the lower the temperature, the greater the release rate, and is generally in the range of -10 to 80°C. Further, when kept at high temperature, it may be used as it is in an aqueous solution, or it may be separated by a filtration method or the like and stored as it is or in a dry state. The retention capacity of these compounds varies depending on the composition of the resin and the compounds to be retained, but is generally 1 to 1000 mg/g of resin,
It can be completely released by lowering the temperature. In addition, retention and release can be achieved by controlling the pH of the aqueous solution. In other words, on the acidic side, ampholytes such as amino acids and proteins are retained at a pH below their isoelectric point, and on the alkaline side, they are released at a pH above the isoelectric point of the ampholyte.
Each can be given priority. That is, retention and release can be controlled by temperature and pH. In addition, regarding the regeneration of the resin, it is possible to release the retained substance using the method described above and then retain it again in that state, or after release, it can be further washed thoroughly by contacting with cold water or an alkaline solution and regenerated. You may do so. Furthermore, the above-mentioned substances can be integrated by coating with the resin of the present invention, etc., and released at any temperature and pH. Next is the selection of the resin composition, but since it changes depending on the substance to be retained, it is preferable to conduct a test in advance each time. As a guideline, when holding a highly hydrophobic substance, an adsorption resin with relatively low hydrophobicity is used, and vice versa when holding a low hydrophobic substance. In this case, if a copolymer with an ionic monomer is used, both cationic and anionic ionicity can be introduced into the resin, and ionic interaction can also be used when retaining various substances, making it more selective. retention and release. In addition, if a copolymer with N-(ω-glycidoxyalkyl)acrylamide such as N,N-diglycidyl acrylamide or N-(4-glycidoxybutyl)acrylamide is used, the resin will have high reactivity. Epoxy groups can be introduced, and by reacting and introducing amino acids, antigens, antibodies, proteins such as enzymes, and even dyes, it is possible to combine affinity and interaction to retain various substances, making it more selective. retention and release. Effect: As described above, basically any substance can be retained and released by the resin of the present invention as long as it is water-soluble. Among them, those that are particularly useful industrially are (1) Fertilizers such as ammonium sulfate and urea, (2) Pesticides such as insecticides, fungicides, herbicides, and plant growth regulators, (3) Phenols, alcohols, (4) Carboxylic acids, (5) Amino acids, (6) Pharmaceuticals such as antibiotics, anticancer drugs, psychiatric drugs, autonomic nervous drugs, vitamins, liver drugs, etc., (7) Enzymes, proteins, polysaccharides, and foods. , (8) pigments, fragrances, and (9) surfactants. Their specific uses include (1) delayed release of fertilizers and pesticides; (2) phenols, for example, for long-term sustainability of their disinfecting power in various uses; (3) carboxylic acids, for example, long-term sustainability of their antiseptic power. 4) For amino acids, for example, continuous addition of essential amino acids can be controlled by temperature (5)
In pharmaceuticals, for example, controlling the gradual rate by temperature (6)
For enzymes, proteins, polysaccharides, and foods, for example, controlling the amount of essential nutrients added to drinking water etc. by temperature (7) For pigments and fragrances, for example, detecting temperature changes by color or scent (8) For surfactants, For example, continuous addition can be controlled by temperature.
A wider range of applications is possible. As described above, the retention/release resin of the present invention (1) is capable of retaining and releasing a wide variety of water-soluble substances as they are; (2) Since retention and release can be controlled by temperature and pH, retention and release can be performed under various conditions. (3) Since the resin can be easily recycled, it has the advantage of being able to be recycled and used any number of times. The present invention will be further explained below with reference to Examples. Example 1 124.95 g of N-acryloylpyrrolidine, 374.85 g of N-acryloylpiperidine, and 10.0 g of N,N'-methylenebisacrylamide were added to 1170 g of distilled water.
to prepare a mixed aqueous solution of N-acryloylpyrrolidine, N-acryloylpiperidine, and N,N'-methylenebisacrylamide. After the aqueous solution was cooled to 10° C., it was transferred to a stainless steel brewer bottle (No. 2), and nitrogen gas was bubbled through it for 1 hour using a ball filter at a flow rate of 1/min. Then, 2.55 g of ammonium persulfate was added to the aqueous solution.
and a solution prepared by dissolving 1.16 g of sodium bisulfite in 10 g of distilled water were simultaneously added, and the aqueous solutions were polymerized adiabatically. The obtained gel was shredded, dried, and then further crushed to a size of 20 to 100
The mesh fraction was collected and used as a sample. Add 2g of the sample powder to 100ml of a 310ppm phenol aqueous solution.
After stirring at 40° C. for 15 minutes, the mixture was filtered through a glass filter to obtain 3.8 g of swollen gel. By measuring the phenol concentration of the filtrate,
The swollen gel was found to retain 16.0 mg of phenol. When 0.475 g of the swollen gel (phenol retention amount 2.0 mg) was packed into a glass column with an inner diameter of 1.0 cm and a length of 10 cm, distilled water was passed through the column at a flow rate of 3.5 ml/min at 0.5°C. After 45 minutes, the phenol concentration of the solution after passing was below the detection limit. When the phenol concentration of the obtained liquid was measured, it was found that 99% of the phenol retained in the swollen gel was
% was released. The concentration of phenol was determined by measuring the absorbance of the liquid at 254 mm. Example 2 Using 0.475 g of the swollen gel containing 2.0 mg of phenol obtained in Example 1, the release time and amount released at 40°C were measured in the same manner as in Example 1. Although the phenol concentration in the liquid after the solution was below the detection limit, the amount of phenol released was 78% of the amount retained. Examples 3 to 10 Sample powders were obtained by polymerizing and pulverizing the copolymer compositions shown in Table 1 in the same manner as in Example 1, and using the sample powders, the compositions shown in Table 1 were prepared in the same manner as in Example 1.
A swollen gel retaining the substances shown in was obtained. Using the swollen gel, the release time and release rate at each temperature were measured in the same manner as in Example 1, and the results shown in Table 1 were obtained. Examples 11 and 12 A sample powder was obtained by polymerizing and pulverizing the copolymer composition shown in Table 2 in the same manner as in Example 1, and using the sample powder, the pH of the aqueous solution of the substance to be retained was determined using hydrochloric acid. A swollen gel retaining the substances shown in Table 2 was obtained by the same method as in Example 1, except that the gel was adjusted to 3. Using the swollen gel, the pH of distilled water
The release time and release rate at each temperature were measured in the same manner as in Example 1, except that the temperature was adjusted to 3 using hydrochloric acid, and the results shown in Table 2 were obtained. Examples 13 and 14 Using the sample powder obtained in Example 1,
The release time and release rate at each temperature of the substances shown in Table 2 were measured by the same method as in No. 11, and the results shown in Table 2 were obtained.

【table】

[Table] Methylenebisacrylamide

[Table] Examples 15 to 18 Example 1 was prepared using the swollen gel obtained in Examples 11 to 14 and retaining the substances shown in Table 3 and distilled water whose pH was adjusted to 8 using sodium hydroxide. The release time and release rate at each temperature were measured using the same method as above, and the results shown in Table 3 were obtained. Example 19 2 g of the sample powder obtained in Example 5 was added to 100 ml of 0.2% ammonium sulfate aqueous solution, and the mixture was heated at room temperature for 15 min.
After stirring for a minute, the mixture was filtered through a glass filter to obtain 16.4 g of swollen gel (28.8 mg of ammonium sulfate retained). Using 2.0 g of the swollen gel (3.5 mg of ammonium sulfate retained), the release time and release rate of ammonium sulfate at various temperatures were measured in the same manner as in Example 1. I got a result of 97% in 1.5 hours. Note that the concentration of ammonium sulfate was determined by measuring the electrical conductivity of the liquid.

[Table] Examples 20 to 25 Table - The release time and release rate of the substances shown in Table 4 were measured, and the results shown in Table 4 were obtained. Examples 26 to 29 The substances shown in Table 5 were prepared in the same manner as in Example 11 using the dried gel powder obtained by drying the swollen gels obtained in Examples 11 and 13 at 60°C overnight. The release time and release rate were measured, and the results shown in Table 5 were obtained. Examples 30 to 33 Using the dry gel powders obtained in Examples 26 and 28, the release time and release rate of the substances shown in Table 5 were measured in the same manner as in Example 15. We obtained the results shown below.

【table】

[Table] Example 34 Using 0.25 g of dry gel powder (3.6 mg of ammonium sulfate retention) obtained by drying the swollen gel obtained in Example 19 overnight at 60°C, the same method as in Example 19 was carried out. When the release time and release rate of ammonium sulfate at each temperature were measured, it was found that at 0.5℃ it took 4.25 hours.
The results were 84% and 96% in 1.5 hours at 80℃. Example 35 30% of N-isopropylacrylamide with 2.0wt% N,N'-methylenebisacrylamide
A sample powder was obtained in the same manner as in Example 1 using an aqueous solution. Example 1 was carried out using 2 g of the powder and 100 ml of a phenol aqueous solution with a concentration of 310 ppm.
In the same manner as above, 4.1 g of a swollen gel holding 12.0 mg of phenol was obtained. 0.513g of the swelling gel
When the release time and release rate at each temperature were measured using the same method as in Example 1 using (1.50 mg of phenol retained), at 0.5°C, after 1 hour, 95%
of phenol was released, with a release rate of 81% after 5.5 hours at 60°C. Example 36 30 of N,N'-diethylacrylamide containing 2.0wt% N,N'-methylenebisacrylamide
% N,N-dimethylformamide solution was transferred to a dewar bottle, and the solution was purged with nitrogen. Then, 1.5% of azobisisobutyronitrile was added at 30° C. to polymerize 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. Using 2 g of the powder and 100 ml of an aqueous phenol solution having a concentration of 310 ppm, 2.4 g of a swollen gel holding 13.0 mg of phenol was obtained in the same manner as in Example 1. The swelling gel 0.365
Example 1 using g (phenol retention amount 1.98 mg)
When we measured the release time and release rate at each temperature using the same method as above, we found that at 0.5℃, 97% of phenol was released after 75 minutes, and at 70℃, the release rate was 76% after 6 hours. Ta. Example 37 A sample powder was obtained in the same manner as in Example 1 using a 30% aqueous solution of N-acryloylmorpholine containing 2.0 wt% of N,N'-methylenebisacrylamide. Using 2 g of the powder and 100 ml of an aqueous phenol solution having a concentration of 310 ppm, 3.5 g of a swollen gel holding 15.4 mg of phenol was obtained in the same manner as in Example 1. Using 0.432 g of the swollen gel (phenol retention amount: 1.90 mg), the release time and release rate at each temperature were measured in the same manner as in Example 1. At 0.5°C, 96% of phenol was released after 50 minutes. The release rate was 79% after 5 hours at 80°C.

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 useful substance is added to a resin made by insoluble in water a radical alone or a copolymer of N-alkyl or N-alkylene substituted (meth)acrylamide, or a radical copolymer with other copolymerizable monomers. A method for retaining and releasing a useful substance, the method comprising supporting the useful substance and releasing the supported useful substance in the form of a solution, the rate of release being controllable by temperature and/or pH.