JP3188283B2 - Liquid absorbent - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to water or water containing as a main component a crosslinked N-vinylcarboxylic acid amide resin obtained by crosslinking the main chain of a homo- or copolymer containing an N-vinylcarboxylic acid amide component with a crosslinking agent. It relates to a liquid absorbent for an organic solvent. More specifically, the present invention is chemically stable, has excellent absorption capacity for organic solvents such as water and alcohol, and particularly has a good absorption rate for liquids in which metal ions and organic ions coexist in the system. It is less affected by coexisting ions, and as a result of absorbing liquid, it itself swells and gels to make the coexisting liquid system non-fluid and solidified, and at the same time exhibits uniform release and adhesion, and is cross-linked. The present invention relates to a liquid absorbent that has a wide range of uses in various fields by utilizing the excellent features and functions of a type N-vinylcarboxylic acid amide resin.

[0002]

2. Description of the Related Art Water-absorbing resins are widely used in the fields of medicine, sanitary, food industry, agriculture, civil engineering, etc. by utilizing their water absorption and water retention. In each case, a high swelling ratio and a high gel strength are required.

Conventionally known water-absorbing resins include, for example, a hydrolyzate of a starch-acrylonitrile graft copolymer, a neutralized product of a starch-acrylic acid graft copolymer,
Saponified vinyl acetate-acrylate copolymer,
Examples include a hydrolyzate of an acrylonitrile or acrylamide copolymer crosslinked product, and a polyacrylate salt crosslinked product. However, these water-absorbing resins are all crosslinked with a polyelectrolyte, and therefore exhibit excellent swelling performance with respect to water containing no electrolyte. However, blood, urine, aqueous fertilizers, cement slurries, etc. It shows only a very low swelling rate for aqueous liquids containing high amounts of these electrolytes.

[0004] It is considered that such a phenomenon appears as a result of a reduction in the spread of the chain because the dissociation of the polymer electrolyte which is the main chain of the crosslinked product is suppressed in the presence of ions. Furthermore, when polyvalent metal ions are present, ionic cross-linking occurs further via the main chain carboxylic acid, and a cross-linked polymer having an unnecessarily high cross-link density also contributes to a decrease in the swelling ratio.

In order to solve such disadvantages, for example, Japanese Patent Application Laid-Open
Japanese Patent Application Laid-Open No. 61-97312 discloses a method for producing a water-absorbent resin containing a carboxyl group in a chain structural unit by graft-polymerizing an acrylic acid compound or the like onto hydroxyethyl cellulose and then hydrolyzing it. This is a method of obtaining an ion-resistant water-absorbing resin by introducing a nonionic polymer into the polymer electrolyte main chain, but it is not always necessary in terms of the chemical stability of the main chain or the simplicity of the manufacturing method. This is not a satisfactory method.

JP-A-60-55011 discloses (meta)
An aqueous solution of an electrolyte such as saline is absorbed by polymerizing three kinds of compounds of an acrylamide compound, a (meth) acrylic acid compound, and a (meth) acrylic compound having a sulfonic acid group at a terminal in the presence of a divinyl compound. A method for producing a water-absorbent resin with improved water-absorbing properties is disclosed. Further, a water-swellable crosslinked polymer containing an N-vinyl compound is disclosed in
No. 58-5305, all proposed to introduce a relatively strong dissociation group of ionic dissociation strength, in order to avoid that the expansion of the main chain to the electrolyte solution is suppressed, Substantially no (meth) acrylamide or N-vinyl compound is a main component, and a water-absorbing resin having high ionic resistance has not been obtained.

Further, as described above, since the main chain is a polyelectrolyte, the swelling gel necessarily contains a large amount of electrolyte. However, it cannot be said that the water rehydration material is sufficiently effective, and a material having a high function has been demanded in this field. Similarly, these rehydration materials are required to have excellent light resistance due to their usage, but this point has not yet been sufficiently solved.

As the name implies, conventional water-absorbing resins form a gel by absorbing water, but these resins do not exhibit any swelling properties in organic solvents such as alcohols. Therefore, its use has been limited to purposes such as water absorption and water retention.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to provide the disadvantages of known water-absorbing resins represented by sodium polyacrylate crosslinked products, particularly, inorganic and organic ions such as metal salts, amines and carboxylic acids. For liquids (electrolyte solutions) that coexist, the absorption capacity is significantly reduced and the lack of chemical stability, which is a drawback of natural polymer compounds or their chemically modified products, is improved. It has the ability to absorb alcohol and other organic solvents, and the gel formed by the absorption of liquid has good adhesion, and has excellent performance in reusing absorbed water by plants and the like. The object of the present invention is to develop a liquid absorbent having:

[0010]

According to the present invention, there is provided a homopolymer comprising a repeating unit represented by the following general formula (A):
(A) and a main chain of a copolymer containing a repeating unit of the general formula (B) are crosslinked with a crosslinker other than a bis (N-vinylcarboxylic amide) compound of the following general formula (C). −
A water-containing agent containing a calcium component such as a concrete curing agent, a cement modifying agent, and a moisture absorbent, mainly containing a vinyl carboxylic acid amide resin, a water-retaining agent for planting material or an artificial medium,
Alternatively, a liquid absorbent is provided as a dispersant for a metal salt solution (complex forming agent with a metal compound).

[0011]

Embedded image

[0012]

Embedded image

In the above formulas (A) and (B), R ¹ , R ²
And R ³ each independently represent a hydrogen atom or a methyl group;
Is a group -COOY (where Y is a hydrogen atom, an alkali metal, C ₁
A C ₆ -C ₆ alkyl group or a lower alkyl group (preferably a C ₁ -C ₆ alkyl group) substituted with a hydroxyl group, a dialkylamino group or a quaternary ammonium group;
CONHZ (where Z is a hydrogen atom or a dialkylamino group,
A quaternary ammonium group, a lower alkyl group substituted with sulfonic acid or an alkali metal salt thereof (preferably C
₁ -C ₆ represents an alkyl group)), a cyano group, 2-Ketopirorijiniru group, a lower alkoxy group (preferably C ₂ -C
_A lower acyl group (preferably an acyl group having 1 to 4 carbon atoms in an alkyl group), a lower acyloxy group (preferably an acyloxy group having 1 to 4 carbon atoms in an alkyl group), or sulfonic acid or an alkali thereof. It represents a lower alkyl group (preferably a C ₁ -C ₃ alkyl group) substituted with a metal salt. When R ³ is a methyl group, X represents a cyano group, a 2-ketopyrrolidinyl group, a lower alkoxy group, a lower acyl group, A lower acyloxy group and a lower alkyl group substituted with a sulfonic acid or a salt thereof,
M represents a hydrogen atom, an ammonium group or an alkali metal, and p represents 0 or 1. In the above formulas (C) and (D), R ⁴ represents a hydrogen atom or a methyl group, R ⁵ represents an alkylene group having 3 to 10 carbon atoms , — (CH ₂ .CHR ⁶ .O ) _n —CH ₂
CHR ⁶ — (wherein R ⁶ represents a hydrogen atom or a methyl group, n represents an integer of 1 to 4) or a group of the above formula (D) (where m represents 0 or 4)] Is shown.

The preferred resin is composed of the component (A) in the main chain and the component
The molar ratio with (B) is 50-100: 50-0, and the average degree of polymerization is 100.
500500,000 and the crosslink density is 1 / 10-1 / 500,000.

According to the present invention, it is chemically stable, has excellent light fastness, has an excellent absorption capacity with respect to water and organic solvents such as alcohols, and particularly contains metal salts, amines and carboxylic acids in the system. Demonstrates high water absorption (organic absorption solvent) magnification for liquids in which inorganic and organic ions coexist, such as swelling and gelling, making the coexisting liquid system non-fluid, solidifying and releasing slowly. The present invention provides a liquid absorbent having a wide range of applications in various fields utilizing the excellent characteristics and functions of a resin obtained by crosslinking a trunk polymer containing N-vinylcarboxylic acid amide as a main component and exhibiting adhesion.

The liquid absorbent of the present invention basically has a function of absorbing water and an organic solvent as described above, but the water or the organic solvent absorbed by the resin may be released depending on external circumstances. Since the function of absorption-retention-release is reversible, these liquids have a regulating function (for example, in the case of an aqueous system, absorption (de) water, water retention, water supply,
Water regulation etc.). Moreover, since the resin of the present invention is chemically stable and excellent in light resistance, it can be repeatedly expressed many times, and the water retained in the resin has good reusability by plants and the like, and germination, germination Does not adversely affect roots and growth.

The resin which has absorbed the liquid itself swells and gels, but the system (liquid) to which the resin is added is suppressed in its flowability as a whole, and eventually becomes non-fluidized and solidified.
Therefore, the added system has shapeability, and the non-fluidized, solidified (shaped) system has a certain degree of elasticity from a very soft state depending on conditions. Various states can be taken up to the molded product, and various functions are exhibited according to each state. For example, in a relatively soft state, it has adhesion to an object, exhibits sealing properties and a certain kind of adhesiveness, and, in a molded article having elasticity, the above-mentioned water retention, water supply and the like. In addition, it absorbs vibration and shock, and exhibits sound absorption.

The liquid absorbent of the present invention can further utilize properties such as sustained release of the components held in the gel, conductivity of water, and high specific heat (heat storage, cooling, heat retention). . The function of absorbing, retaining, (slowly) releasing, and non-fluidizing the liquid organic compound is one of the major features of the absorbent of the present invention together with the above-mentioned ionic resistance, and is a performance not found in conventional absorbents.

The functions of absorbing, releasing and controlling these liquids, releasing them slowly, reducing the fluidity of the added system, solidifying,
Various functions such as shaping properties or adhesion to the outside world, covering properties, etc. are so-called causes and effects, and a series of closely related phenomena are viewed from various viewpoints. Absorption-gelation. Therefore, in the present invention, the term liquid absorbent should not be interpreted in a narrow sense only in terms of simply absorbing liquid, and as a result of the use of the crosslinked N-vinylcarboxylic acid amide resin as described above ( It also means various functions, actions, and phenomena that are provided.

Such various functions (basically, an absorbent for water and an organic solvent) are obtained by crosslinking the main chain of a homo- or copolymer containing at least 50 mol% or more of an N-vinylcarboxylic acid amide component with a crosslinking agent. This is brought about by the use of a cross-linked N-vinylcarboxylic acid amide resin. The components A (N-vinylcarboxylic acid amide) and B (copolymer) of the repeating unit represented by the above general formula are each used as a monomer. Specific examples of typical examples include the following.

Component A: N-vinylformamide, N-vinylacetamide, N-methyl-N-vinylformamide, N-methyl-N-vinylacetamide, etc. are preferred, with N-vinylacetamide being particularly preferred.

Component B: acrylic acid, methacrylic acid (hereinafter collectively referred to as (meth) acrylic acid) or an alkali metal salt thereof such as a sodium salt and a potassium salt;

The methyl ester, ethyl ester, propyl ester, butyl ester, pentyl ester,
Alkyl esters such as hexyl ester, heptyl ester, octyl ester, nonyl ester, decyl ester, stearyl ester, palmityl ester;

Hydroxy lower alkyl esters such as hydroxyethyl ester, hydroxypropyl ester and hydroxybutyl ester;

The lower group substituted by a lower alkylamino group such as dimethylaminomethyl ester, dimethylaminoethyl ester, dimethylaminopropyl ester, dimethylaminobutyl ester, diethylaminomethyl ester, diethylaminoethyl ester, diethylaminopropyl ester and diethylaminobutyl ester Alkyl esters;

The trimethylammonioethyl ester halide, trimethylammoniopropyl ester halide, triethylammonioethyl ester halide,
Lower alkyl esters substituted with a quaternary ammonium group such as triethylammoniopropyl ester halide;

The amide;

Amides substituted by lower alkylamino groups such as dimethylaminomethylamide, dimethylaminoethylamide, dimethylaminopropylamide, dimethylaminobutylamide, diethylaminomethylamide, diethylaminoethylamide, diethylaminopropylamide and diethylaminobutylamide ;

A lower alkylamide substituted by a quaternary ammonium group such as trimethylammonioethylamide halide, trimethylammoniopropylamide halide, triethylammonioethylamide halide, triethylammoniopropylamide halide;

The sulfomethylamide, sulfoethylamide, sulfopropylamide, sulfobutylamide, sodium sulfomethylamide, sodium sulfoethylamide, sodium sulfopropylamide, sodium Lower alkyl amides substituted with sulfonic acids or alkali metal sulfonic acids such as sodium sulfobutylamide, potassium sulfomethylamide, potassium sulfoethylamide, potassium sulfopropylamide, and potassium sulfobutylamide;

Acrylonitrile;

N-vinyl-2-pyrrolidone;

Vinyl ethers such as methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether and butyl vinyl ether;

Vinyl ketones such as methyl vinyl ketone and ethyl vinyl ketone;

Lower vinyl carboxylate such as vinyl acetate and vinyl propionate;

Allyl sulfonic acid such as allyl sulfonic acid, sodium allyl sulfonate, potassium allyl sulfonate and the like, or alkali metal salts thereof;

Maleic acid, sodium maleate, potassium maleate, fumaric acid, sodium fumarate,
Itaconic acid, sodium itaconate, potassium itaconate and the like can be mentioned.

Among these, (meth) acrylic acid,
Sodium (meth) acrylate, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, hydroxyethyl (meth) acrylate, hydroxypropyl (meth)
Acrylate, hydroxybutyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, trimethylaminoethyl (meth) acrylate, acrylamide, sulfopropylacrylamide, sulfobutylacrylamide, sodium sulfopropylacrylamide, sodium sulfate Phobutyl acrylamide,
Acrylonitrile, methyl vinyl ether, ethyl vinyl ether, methyl vinyl ketone, ethyl vinyl ketone, vinyl acetate, sodium allyl sulfonate, N-
Preferred are vinyl-2-pyrrolidone, maleic acid, sodium maleate, itaconic acid, sodium itaconate, and the like.

In the case of the copolymer, the component A must be contained at least at least 50 mol% as described above, and below this, the ionic resistance, absorption of organic compounds, and light resistance, which are characteristics of the absorbent of the present invention, will be described below. The property is not fully exhibited. Since the preferred range of the copolymer composition varies depending on the type of liquid to be absorbed, particularly the type and concentration of coexisting solutes, it cannot be unconditionally stated, but is preferably in a molar ratio of 50 to 99: 1 to 50,
More preferably, it is 70 to 99: 1 to 30.

As the cross-linking agent, a compound having at least two polymerizable unsaturated groups in one molecule is used. Typical examples thereof include the following compounds. Can be

N, N'-methylenebisacrylamide,
Ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, divinyl Benzene, divinyl ether.

The amount of the crosslinking agent used is 2 × 10 ^-4 to 10 mol%, preferably 2.5 × 10 ⁴ mol%, based on the (co) polymerization component.
^{-4 to} 2 mol%, particularly preferably 5 × 10 ^-4 to 1 mol%. When the amount of the crosslinking agent used is more than 10 mol% based on the (co) polymerized component, the cross-linking density of the obtained resin becomes too high, so that its absorption performance is remarkably reduced. If the amount is less than 10 ^-4 mol%, the proportion of polymer chains that are not crosslinked increases, and the polymer chains are easily dissolved in water or an organic solvent, so that the performance expected as an absorbent cannot be exhibited.

The polymerization process is not particularly limited, but it is usually preferable to employ a method such as an aqueous solution polymerization method, a reversed phase suspension polymerization method, a reversed phase emulsion polymerization method, or the like. For example, in the aqueous solution polymerization method, a monomer component and a cross-linking agent are uniformly dissolved in a solvent such as water or a hydrophilic organic solvent which can be uniformly mixed with water, or a mixed solvent thereof, and then deaerated in vacuum or nitrogen gas or carbon dioxide gas. After removing the dissolved oxygen in the system by replacement with an inert gas such as the above, a polymerization initiator is added and reacted. The polymerization initiation temperature is usually about −10 to 60 ° C., and the reaction time is 1 to
About 10 hours.

Representative examples of the hydrophilic organic solvent include lower alcohols such as methyl alcohol, ethyl alcohol and propyl alcohol, cyclic ethers such as tetrahydrofuran and dioxane, acetone, acetonitrile, dimethylformamide, dimethylacetamide, and the like. Dimethyl sulfoxide and the like. Among these, tetrahydrofuran, acetonitrile,
Dimethylformamide, dimethylacetamide, dimethylsulfoxide and the like are preferred.

Examples of the polymerization initiator include peroxides, organic and inorganic peracids or salts thereof, which are uniformly dissolved in a solvent.
Redox-based azobis-based compounds alone or in combination with a reducing agent are used, and typical examples thereof include the following.

T-butyl peroxide, t-amyl peroxide, cumyl peroxide, acetyl peroxide, propionyl peroxide, benzoyl peroxide, benzoylisobutylylyl peroxide, lauroyl peroxide, t-butyl hydroperoxide, cyclohexyl Hydroperoxide, tetralin hydroperoxide, t-butyl peracetate, t-butyl perbenzoate, bis (2
-Ethylhexyl peroxydicarbonate), 2,2
-Azobis i-butyronitrile, phenylazotriphenylmethane, 2,2-azobis (2-amidinopropane) dihydrochloride, 2,2-azobis [2- (5-methyl-
2-imidazolin-2-yl) propane] dihydrochloride,
2,2-azobis [2- (2-imidazolin-2-yl) propane] dihydrochloride, sodium persulfate, potassium persulfate, ammonium persulfate, hydrogen peroxide, persulfate and triethylamine, triethanolamine, dimethylaniline And the like with a tertiary amine.

Of these, t-butyl peroxide, benzoyl peroxide, 2,2-azobis i-
Butyronitrile, 2,2-azobis (2-amidinopropane) dihydrochloride, 2,2-azobis [2- (5-methyl-2-imidazolin-2-yl) propane] dihydrochloride,
2,2-azobis [2- (2-imidazolin-2-yl) propane] dihydrochloride, sodium persulfate, potassium persulfate, or ammonium persulfate alone or a combination of these persulfates with triethylamine, triethanolamine or dimethylaniline And the like.

The polymerization initiator is used in an amount of 0.0005 to 5 mol%, preferably 0.001 to 5 mol%, based on the (co) polymerization component.
To 1 mol%, particularly preferably 0.005 to 0.5 mol%. When the amount of the polymerization initiator used is more than 5 mol% based on the (co) polymerization component, the degree of polymerization of the main chain polymer chains does not increase, and the proportion of non-crosslinked polymer chains increases. The desired performance as an absorbent cannot be exhibited because it is easily dissolved in water and organic solvents. On the other hand, when the content is less than 0.0005 mol%, the reaction rate of the polymerization reaction does not increase and the amount of residual monomer increases. There is.

The reaction product is in the form of a gel containing the solvent used in the reaction, and is usually pulverized with a rotary cutter or the like.
The solvent is removed by a method such as heating or depressurization, dried and pulverized and classified to obtain a powder having a particle size of about 50 μm to 1 mm.

In the reversed-phase suspension polymerization method and the reversed-phase emulsion polymerization method, a monomer component and a crosslinking agent are uniformly dissolved in water, and the resulting solution is suspended or emulsified in an organic solvent which is not uniformly mixed with water. Let it react. As the polymerization initiator, not only a water-soluble polymerization initiator but also a polymerization initiator soluble in an organic solvent is used. Therefore, in addition to the above, for example, hexane, cyclohexane, heptane, octane, benzene,
Hydrocarbons such as toluene, xylene and ethylbenzene, halogenated hydrocarbons such as carbon tetrachloride and dichloroethane, and mineral oils such as Isopar are also used. In the reverse-phase emulsion polymerization method, a surfactant is used as a dispersant, and a protective colloid is used together if necessary. Representative examples thereof include, for example, sorbitan monostearate, sorbitan monopalmitate, polyvinyl alcohol, methyl cellulose, ethyl cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, carboxyethyl cellulose, and the like.

The removal of dissolved oxygen in the system, the treatment of the reaction product, and the like are the same as described above, and the reaction conditions are not necessarily limited. The amount of the polymerization initiator is preferably 0.0005 to 5 mol%, preferably 0.001 to 1 mol%, particularly preferably 0.005 to 1 mol% based on the monomer component. The polymerization initiation temperature is about 10 to 90 ° C, and the reaction time is about 1 to 10 hours.

The molecular structure of the resin thus obtained was such that a linear polymer composed of a homopolymer of N-vinylcarboxylic acid amide or a copolymer with another copolymerization component formed a main chain, which was crosslinked by a crosslinking agent. Has a three-dimensional structure,
Mainly, the molecular size and the state of cross-linking, that is, the molecular weight of the main chain and the cross-link density largely control the function as the liquid absorbent of the present invention. For example, in theory, the main chain can be made as large as possible, and the cross-link density can be made as small as possible to increase the liquid absorption capacity. However, the liquid absorption capacity has its own limit, and the distance between cross-links is limited. As the size increases, the physical strength of the gel formed by absorbing the liquid is remarkably reduced, and the number of molecules that do not participate in crosslinking increases to increase the solubility. Therefore, the degree of polymerization of the main chain: 500,000 to 100, preferably 400,000 to 1,000, particularly preferably 200,000 to 1
0,000, and the crosslinking density is 1 / 500,000 to 1/1.
It is important that it is in the range of 0, preferably 1 / 400,000 to 1/50, particularly preferably 1 / 200,000 to 1/100.

When the main chain is a copolymer, there is a slight difference in its structure due to the difference in reactivity of the copolymer components.
For example, when acrylamide, maleic acid, or the like is used as a copolymer component, alternate polymerization is often performed depending on the molar ratio of the charged reactants. When acrylic acid or the like is used, block copolymerization is often used, and when vinyl acetate or the like is used, random copolymerization is often used. However, the structural difference of the main chain copolymer due to the difference in the reactivity of these copolymer components may cause a characteristic function to be added in each use example, but the liquid absorption of the present invention as a whole It is not essential in the agent.

The cross-linked N-vinylcarboxylic acid amide resin (liquid absorbent) of the present invention has a diameter of 50 μm or more as described above.
It can be obtained in the form of a powder of about 1 mm, but in the state of absorbing liquid, it is in the form of beads or a dispersion, cream, paste-like viscous material, etc., and is formed into a string, film, sheet,
It can be used in various shapes and forms in combination with various bases (materials).

The liquid absorbent containing the crosslinked N-vinylcarboxylic acid amide resin of the present invention as a main component is basically composed of water and an organic solvent having ionic resistance, chemical stability and light resistance as described above. The superior absorption function is mainly used for liquid absorption, release and control functions and sustained release properties, decrease in fluidity to the added system, solidification, shapeability or adhesion to the outside world, sealing property and a kind of Adhesive, covering,
A molded article having elasticity absorbs vibration and impact in addition to the above-described water retention, water supply, etc., and exhibits sound absorption. Furthermore, the sustained release of the components held in the gel and the conductivity of water,
Properties such as high specific heat (heat storage, cooling, heat retention) are also available.

In the liquid absorbent of the present invention, particularly, a crosslinked product of sodium polyacrylate, which is a typical example of a water-absorbing polymer, is added to the liquid to be absorbed by inorganic or organic compounds such as metal salts, amines and carboxylic acids. In the case where ions coexist, there is a disadvantage that the water absorption performance is remarkably impaired. On the other hand, the water absorption performance is hardly affected by the coexistence of ions. In addition, the water absorbed and retained in the resin has good reusability by plants and the like, and does not adversely affect germination, rooting, and growth. Applications that take advantage of such features, for example, general farmland,
In addition to forests, of course, relatively salty soil such as desert greening, or medium containing inorganic salts or fertilizers such as tissue culture or artificial cultivation, water solution for artificial cultivation (water supply); sanitary goods (diapers,
Absorbent for body fluids (urine, menstrual blood) with high salt content such as napkins and tampons; absorbent for water with high calcium content such as concrete curing and cement modifier; non-fluidizing agent for deliquescent of calcium chloride-based hygroscopic agent A metal salt solution dispersant (composite forming agent with a metal compound) for producing ultrafine ceramics;

In the liquid absorbent of the present invention, in particular, the liquid to be absorbed of a crosslinked product of sodium polyacrylate, which is conventionally represented by a water-absorbing polymer, is limited to water or a mixture of water and some lower alcohols. On the other hand, it can also absorb water, various organic solvents or mixtures thereof. Specific examples of typical organic solvents that can be absorbed include, for example, the following, which are generally referred to as relatively high polar solvents.

Methanol, ethanol, 1-propanol, 1-butanol, 2-butanol, isobutyl alcohol, isoamyl alcohol, cyclopentanol,
Allyl alcohol, 1,1,1,3,3,3-hexafluoro-2-propanol, 2-methoxyethanol,
2-ethoxyethanol, 2-butoxyethanol, 2
Alcohols such as aminoethanol, ethylene glycol, trimethylene glycol, propylene glycol, 1,4-butanediol, 1,3-butanediol, 2,3-butanediol, triethylene glycol and glycerin; phenol, cresol and the like Phenols;
Others include formamide, acetic acid, 2-pyrrolidinone, dimethylsulfoxide, pyridine and the like. Further, they have no or very poor absorption by themselves, but can be absorbed in a mixed system, for example, water and N , N-dimethylformamide, phenol, acetone, tetrahydrofuran or dioxane, etc .; water-organic solvent system; ethanol-
A mixed solvent system of organic solvents such as acetone, ethanol-chloroform, ethanol-benzene, ethanol-ethyl acetate, methanol-methylene chloride, and ethyl acetate-acetic acid is shown.

The liquid absorbent of the present invention can be used in such a wide range.
Although the reason for absorbing the solvent is not always clear, the present invention
-Linked N-vinyl carboxy as a main component of liquid absorbent
Strength of interaction between acid amide resin and absorbable solvent system
As a measure, the high polarity of the solvent system can be considered. General
In addition, dielectric constant (ε), solubility
Degree parameter (δ), solvent polarity parameter (E_TValue
Is known as the Z value).
As a result of various analyses, each of the above organic solvents was a single solvent
Then E_TValue is 45 or more.
E of medium system_TValue is 43 or more, and conversely, it is less than this value
Was hardly absorbed. Therefore,
Organic solvents that can be absorbed by bright liquid absorbent
E in the medium _TValue is 45 or more._T
It can be said that the value is 43 or more. In particular, E_TValue and
Absorbency relationship applies well to single solvents, mixed solvents
E in each case_TValue of 50 or more, more preferably 53 or more
Things.

Examples of uses of the liquid absorbent of the present invention include the following in addition to the above-mentioned ones. Of course, these are merely examples, and the use of the liquid absorbent of the present invention is not limited to the following, and it can be used in a wide variety of fields and products by utilizing the above functions. It is.

Food products (freshness preserving products, dehydration, water retention, water supply, water regulators); agricultural and horticultural products (soil improvers, seedlings and cultivation base materials, planting materials (planting, desert greening, etc.) Agent,
Seed preparations, anti-frost and dew-prevention agents (materials)); Household and architectural moisture absorption, dew-prevention, drip-proofing agents; Communication cables, waterproofing of equipment, dehydration of water-stopping agents (materials), water retention, water supply, Moisture regulator,
Oral and enteral pharmaceuticals, health foods, feed additives, agricultural chemicals, fertilizers, etc. Various sustained-release preparations Medical supplies (pastes, mucosal preparations, suppositories); Auxiliaries for various preparations (binders, coatings) Adhesives, covering bases and assistants for civil engineering, construction, home use, various industrial sealing agents, putty, paint auxiliaries, adhesive tapes, salt damage and dust prevention agents (materials); Drilling aids and lubricants for foundations such as sandbags, sandbags, pore shields and mines, tunnels, buildings and piers; household fragrances, deodorants, fire extinguishers, heat storage agents (cooling, heat retention); batteries, electrodes, sensors Materials; electrical components such as antistatic agents (materials); conductivity improvers (materials); heat insulation (convection) prevention, vibration absorption, sound absorbing materials, packing; cosmetics (scrub face wash, pack agents); contact lens cleaning agents, etc. Fluidity, solidification, or excipients in

Specific use of the liquid absorbent of the present invention,
The amount of use is somewhat different depending on each application, so it cannot be said unconditionally. However, in principle, it does not greatly differ from general and standard specifications in each application. However, because of its excellent functions and effects, it is possible to expect use cases that have never been seen before,
Needless to say, the amount of use can be reduced to achieve the same effect.

[0063]

EXAMPLES Hereinafter, the present invention will be described more specifically by showing typical examples of the liquid absorbent of the present invention as examples.
It is needless to say that these are merely examples and do not limit the scope of the present invention.

Example 1 A glass reactor was charged with 750 g of water, and 200 g (2.4 mol) of N-vinylacetamide and 1.0 g of N, N'-methylenebisacrylamide as a crosslinking agent were added and dissolved. After removing dissolved oxygen with nitrogen gas in advance,
A solution prepared by dissolving 0.4 g of 2,2'-azobis (2-amidinopropane) dihydrochloride in 49.6 g of water was added as a polymerization initiator, and the mixture was reacted for 16 hours under a nitrogen flow. The reaction product in the form of a gel was taken out, subdivided and dehydrated with acetone,
For 5 hours. The dried product was pulverized and classified to obtain a 48 to 100 mesh product. The average degree of polymerization of this resin is 19,000,
The crosslink density was 1/350.

Example 2 A resin was obtained in exactly the same manner as in Example 1 except that N-vinylacetamide was changed to the same weight of N-vinylformamide. The average degree of polymerization of this resin was 20,000, and the crosslink density was 1/420.

Example 3 From N-vinylacetamide to the same weight of N-methyl-N-
The reaction was carried out in exactly the same manner as in Example 1 except that vinylformamide was used, to obtain a resin. The average degree of polymerization of this resin is 18,00
0, crosslink density was 1/350.

Example 4 From N-vinylacetamide to the same weight of N-methyl-N-
The reaction was carried out in exactly the same manner as in Example 1 except that vinylacetamide was used, to obtain a resin. The average degree of polymerization of this resin is 16,00
0, the crosslink density was 1/310.

Example 5 From 200 g of N-vinylacetamide to 160 g (1.88 mol) of N-vinylacetamide and 40 g of sodium acrylate
(0.43 mol), except that the reaction was carried out in the same manner as in Example 1 to obtain a resin. The average degree of polymerization of this resin was 21,000, and the crosslink density was 1/350.

Examples 6 to 28 Example 5 except that the same weight of various copolymerized monomer components was used in place of the non-polymerized monomer component sodium acrylate.
And a resin was obtained. These are summarized in Table 1.

[0070]

[Table 1]

Example 29 From 200 g of N-vinylacetamide to 140 g (1.65 mol) of N-vinylacetamide, 20 g of sodium acrylate (0.2 g
2 mol) and 20 g of sodium 2-acrylamido-2-methylpropanesulfonate were reacted exactly as in Example 1 to obtain a resin. The average degree of polymerization of this resin is 2
The crosslink density was 1,000 and the crosslinking density was 1/310.

Examples 30 to 34 The reaction was carried out in exactly the same manner as in Example 5, except that the same molar amount of various crosslinking agents was used instead of N, N'-methylenebisacrylamide as the crosslinking agent to obtain a resin. Table 2 summarizes these
Shown in

[0073]

[Table 2]

Example 35 150 g (1.76 mol) of N-vinylacetamide as a monomer
l) and 50 g (0.53 mol) of sodium acrylate, 1.0 g of N, N'-methylenebisacrylamide as a crosslinking agent
The reaction was carried out in exactly the same manner as in Example 5 except that the polymerization initiator was changed to 0.29 g of 2,2'-azobis (2-amidinopropane) dihydrochloride to obtain a resin. The average degree of polymerization of this resin was 20,000, and the crosslink density was 1/350.

Examples 36 to 42 The reaction was carried out in the same manner as in Example 35 except that various polymerization initiators were used instead of 2,2'-azobis (2-amidinopropane) dihydrochloride as the polymerization initiator. A resin was obtained. These are summarized in Table 3.

[0076]

[Table 3]

Example 43 N, N'-methylenebisacrylamide was used as a crosslinking agent
Reduce to 0.5g, ethylene glycol dimethacrylate
The reaction was carried out in exactly the same manner as in Example 35 except that 0.5 g was added, to obtain a resin. The average degree of polymerization of this resin is 20,000 and the crosslink density is 1
/ 320.

Example 44 98 g (1.15 mol) of N-vinylacetamide as a monomer
The reaction was carried out in exactly the same manner as in Example 35 except that 107 g (1.14 mol) of sodium acrylate and 1.0 g of N, N'-methylenebisacrylamide were used as a crosslinking agent to obtain a resin. The average degree of polymerization of this resin is 20,000 and the crosslink density is 1/29.
It was 0.

Example 45 A glass reaction vessel was charged with 250 g of water, and 98 g (1.15 mol) of N-vinylacetamide, 107 g of sodium acrylate (1.14 m
ol), 1.0 g of N, N'-methylenebisacrylamide as a crosslinking agent was added and dissolved.
And 20 g of sorbitan monopalmitate, and dissolved oxygen was previously removed with nitrogen gas under a vigorous stirring in a thermostat at 30 ° C., and then 2,2′-azobis (2
A liquid obtained by dissolving 0.4 g of (amidinopropane) dihydrochloride in 49.6 g of water was added, and the mixture was reacted for 16 hours under nitrogen flow. Take out the particulate reaction product dispersed in the solvent, filter and remove 1
Dried at 05 ° C for 5 hours. The dried product was classified to obtain a 48 to 100 mesh product. The average polymerization degree of this resin was 21,000, and the crosslink density was 1/290.

Example 46 A resin was obtained in exactly the same manner as in Example 45 except that the same amount of sorbitan monostearate was used as the surfactant component. The average degree of polymerization of this resin is 21,000 and the crosslink density is 1 /
350.

Example 47 A resin was obtained in the same manner as in Example 45 except that 250 g of N-vinylacetamide alone was used as a monomer.
The average degree of polymerization of this resin was 20,000, and the crosslink density was 1/290.

Example 48 A resin was obtained in the same manner as in Example 47 except that the same amount of sorbitan monostearate was used instead of sorbitan monopalmitate as a surfactant component. The average degree of polymerization of this resin was 20,000, and the crosslink density was 1/290.

Comparative Example 1 90 g of a crosslinking agent N, N'-methylenebisacrylamide
Except for using, reaction was carried out in exactly the same manner as in Example 1 to obtain resin X. This resin has an average degree of polymerization of 18,000 and a crosslink density of 1/4.
Met.

Comparative Example 2 The crosslinking agent N, N'-methylenebisacrylamide
The reaction was carried out in exactly the same manner as in Example 1 except that mg was used, to obtain a resin Y. The average degree of polymerization of this resin is 19,000 and the crosslink density is 1 /
1,200,000.

Comparative Example 3 50 g (0.59 mol) of N-vinylacetamide as a monomer
The reaction was carried out in exactly the same manner as in Example 1 except that 150 g (1.60 mol) of sodium acrylate was used, and a resin Z was obtained. The average degree of polymerization of this resin was 21,000, and the crosslink density was 1 / 15,000.

The monomers, crosslinking agents and initiators in Tables 1, 2 and 3 are as follows. Monomers B ₁ : sodium methacrylate, B ₂ : methyl acrylate, B ₃ : ethyl acrylate, B ₄ : butyl acrylate, B ₅ : butyl methacrylate, B ₆ : hydroxyethyl acrylate, B ₇ : hydroxyethyl methacrylate, B ₈ : Hydroxypropyl acrylate,
B ₉ : hydroxypropyl methacrylate, B ₁₀ : acrylamide, B ₁₁ : dimethylaminoethyl methacrylate, B ₁₂ : dimethylaminoethyl methacrylate methyl chloride quaternary salt, B ₁₃ : sodium 2-acrylamido-2-methylpropanesulfonate, B ₁₄ : Acrylonitrile, B ₁₅ : methyl vinyl ketone, B ₁₆ : ethyl vinyl ketone, B ₁₇ : vinyl acetate, B ₁₈ : methyl vinyl ether, B ₁₉ : ethyl vinyl ether, B ₂₀ : sodium allyl sulfonate, B ₂₁ : N-vinyl- 2-pyrrolidone, B _22: maleic acid sodium, B _23: sodium itaconate

Crosslinking agents C ₁ : ethylene glycol diacrylate, C ₂ : ethylene glycol dimethacrylate, C ₃ : diethylene glycol diacrylate, C ₄ : diethylene glycol dimethacrylate, C ₅ : divinylbenzene

Initiator D ₁ : potassium persulfate, D ₂ : ammonium persulfate, D
_3: sodium persulfate, D _4: hydrogen peroxide, D _5: ammonium persulfate / triethanolamine, D _6: ammonium persulfate / sodium sulfite, D _7: ammonium persulfate / sodium thiosulfate

(Performance test) Test example 1 (Absorption of aqueous solution) 500 mg of an absorbent resin was gradually added to 200 ml of the liquid to be absorbed while stirring, and after the resin was sufficiently dispersed in the liquid, stirring was stopped and the mixture was allowed to stand for 2 hours. After the placement, the resin that had absorbed and swollen and gelled was filtered using a 200-mesh sieve, and the weight of the resin (gel) on the sieve was measured. Absorption capacity = (weight of gelled resin−weight of resin) / weight of resin

Kinds of liquid to be absorbed A: saline solution (0.9% physiological saline) B: mixed aqueous solution of inorganic salt and organic substance (human urine equivalent liquid) NaCl
_{79%, K 2 SO 4 0.20} %, MgSO 4 0.11%, CaCl 2 · 2H 2 O 0.0
8%, Urea 1.94% Ca: Calcium chloride aqueous solution (10%) b: 〃 (saturated aqueous solution) c: Calcium hydroxide aqueous solution (saturated aqueous solution) The results are summarized in Tables 4 to 7.

[0091]

[Table 4]

[0092]

[Table 5]

[0093]

[Table 6]

[0094]

[Table 7]

Test Example 2 (Absorption of Organic Solvent) 100 mg of an absorbent resin was added to 50 ml of the liquid to be absorbed, and the resin was absorbed at room temperature with occasional stirring to form a swelling gel, which was visually observed. Those with good liquid absorbing properties gelled in 30 minutes to several hours, while those without liquid absorbing properties remained almost white powder after one week. Judgment of absorption performance was made for gelation within one day.
Those that did not gel after a week were evaluated as x,
_The results are shown in Tables 8 and 9 (single solvent) and Table 10 (mixed solvent) together with the _T values. In addition, there was substantially no gelation in one day or more to several days. The abbreviations in Tables 8 to 10 are as follows.

HFIP: 1,1,1,3,3,3-hexafluoro-2-propanol THF: tetrahydrofuran DMSO: dimethylsulfoxide NMP: N-methylpyrrolidinone DMF: N, N-dimethylformamide DMAc: N, N-dimethylacetamide

[0097]

[Table 8]

[0098]

[Table 9]

[0099]

[Table 10]

Use Example 1 The water in the water-absorbing gel of the resin of the present invention can be reused by plants, and the water is gradually released. It can absorb and release (supply water) water containing inorganic and organic ionic components, so that it can be used for fertilization, soil improvement, artificial culture, etc., and especially in afforestation and land development in mountains where water is inconvenient. It is convenient for transplanting of seedlings, turf, etc. in the prevention of dust and revegetation, etc., or water retention / supply in deserts, etc. Incidentally, the so-called water-absorbent resin that has been conventionally commercially available has an extremely low water absorption rate containing water containing an ionic component, and also has poor utilization of water in the gel even if it is gelled with water that does not contain ions in advance. The use as described above is difficult because phytotoxicity may occur. Hereinafter, a representative example will be shown and specifically described.

Test resin: A) Crosslinked product of poly N-vinylacetamide (average degree of polymerization of main chain; about 20,000, crosslinking agent: N, N'-methylenebisacrylamide, crosslinking density; about 1/350) B) Poly N -Vinylacetamide / Sodium acrylate-
Crosslinked product (monomer molar ratio; 50:50, main chain average polymerization degree;
About 20,000, crosslinking agent; N, N'-methylenebisacrylamide, crosslinking density; about 1/350) C) crosslinked sodium polyacrylate (average degree of main chain polymerization: about 60,000, crosslinking agent; N, N'- Methylenebisacrylamide, crosslinking density; about 1 / 10,000) D) agar

Effect on growth 1) A gel prepared by adding 1% by weight of a test resin or agar to distilled water and uniformly mixing them in a group of petri dishes (diameter 10 cm), and putting edible shrimp and Lettuce seeds were placed on the floor and allowed to stand in a greenhouse, and their effects on germination, rooting and growth were investigated. Germination, rooting and growth were not significantly different from the agar gel used for comparison in the gel of the test resin A), and the germination was slightly delayed in the gel of the test resin B). There was no particular problem on growth. On the other hand, in the gel of the test resin C), rooting and germination were significantly inhibited, and the growth was very poor.

2) To a group of pots (diameter 15 cm), 1% by weight of each of the test resins was added, and a certain amount of uniformly mixed sand was stuffed, and seeds of wheat were sown. 5 weeks after sowing by thinning out, the standard seedlings
When the water reached about 10 cm, the last water supply was performed and the water supply was left as it was to investigate the withering status of the seedlings. In the pot mixed with the test resin A), wilting began on the 9th day after water cut off, and in the pot mixed with the test resin B), wilting started on the 7th day after water cut off.
On the other hand, in the pot mixed with the test resin C), wilting started on the fourth day after the water was cut off, and with the resin-free sand started on the third day after the water cut off.

3) To a group of pots (diameter 15 cm), 1% by weight of each of the test resins was added and mixed uniformly (volcanic ash soil /
Fill a fixed amount of sand 1: 1 mixed soil)
(Plant length: 15 to 20 cm), transplanted, irrigated once after transplantation, and then allowed to stand for 10 days without water to investigate the status of seedling survival. In the pot mixed with the test resin A), all the transplanted seedlings survived, and in the pot mixed with the test resin B), most of the pots survived. Was. In the pot mixed with the test resin C), nearly 2/3 were dead or almost dead, and the remaining seedlings were also withered.

4) To a group of pots (diameter 15 cm), 1% by weight of the test resin was added, and the mixture was mixed uniformly (volcanic ash soil /
A fixed amount of sand (1: 1 mixed soil) was filled, a fertilizer solution having the following composition was irrigated, and then seedlings of tomato (two true leaves, plant height: 10 to 15 cm) were transplanted to investigate the effect on survival and growth. NH ₄ NO _{3
58ppm, NaNO 3 74ppm, MnSO 4} · 7H 2 O 2ppm, Fe · ED
TA 18ppm, KNO ₃ 58ppm, KH ₂ PO ₄ 38ppm, CaCl ₂・ 2H ₂
In the pot mixed with O 52ppm and the test resin A), no significant difference was observed between the pot with no resin added and the status of rooting and growth,
All the transplanted seedlings showed a vigorous growth state, and most of the pots mixed with the test resin B) also survived and showed a vigorous growth state. On the other hand, most of the pots mixed with the test resin C) were dead or nearly dead after 2 weeks.

Use Example 2 When an aqueous solution or suspension containing a reaction component (metal ion, oxide, etc.) is brought into contact with the resin of the present invention, a gel containing the aqueous solution is formed, which is dried and then heated and calcined. As a result, the resin component is decomposed and vaporized, and the component (metal oxide) incorporated in the matrix of the crosslinked polymer is obtained as fine particles of about several nm. If the heating and sintering are performed in a non-oxidizing atmosphere, fine particles of a mixture or a reaction product with carbon in the resin component can be obtained. In addition, even for a component which evaporates by heating, such as aluminum chloride, its aqueous solution is once gelled, then reacted with ammonium hydroxide to be converted into aluminum hydroxide in the gel, and then heated and calcined. Furthermore, some alumina sols and silica sols are suspended in water as fine particles of about several nm, but can be taken into a polymer matrix as a water-absorbing gel like dissolved components such as metal ions. On the other hand, in order to obtain a ceramic article other than powder, a water-absorbing gel may be formed and then heated and fired.
In this case, it is necessary to cause strong coagulation, contrary to the case of obtaining fine powder particles. Therefore, it is necessary to increase the temperature during heating and firing and lengthen the time depending on the case. In any case, it can be realized by using the resin of the present invention having the ability to absorb an aqueous solution or a colloid solution containing ions as they are and to gel. Hereinafter, a typical example will be specifically described.

Test resin: cross-linked poly N-vinylacetamide (average degree of polymerization of main chain: about 20,000, cross-linking agent: N, N ')
-Methylenebisacrylamide, crosslinking density: about 1/350)

1) Al (NO_Three)_Three・ 9H_TwoDissolve 10 g of O in 25 ml of water
Then, add 1 g of the test resin, mix evenly,
After gelling, dry thoroughly and place in alumina crucible
The temperature rises to 1000 ° C in about 6 hours in a gon stream,
During this time, the mixture was heated to 1000 ° C. and fired. Remove contents after cooling
, Specific surface area sA (BET method), α conversion (X-ray diffraction
Method), median particle diameter d₅₀(Centrifugal sedimentation method) was measured
However, sA: 19 (5) m ^Two / G, α conversion: 94 (90)
%, D₅₀: 0.3 (1) μ, almost no condensation due to heating
I was not able to admit. In addition, the value of () does not use resin
It is a measured value when it is measured. In addition to the above, d₅₀: 0.05μ
A similar test was conducted by adding 10 mg of α-alumina fine particles.
Roller, sA: 17 (3) m^Two / G, α conversion: 99 (95)%,
d₅₀: 0.3 (1) μ. The values in parentheses are all
This is a measured value when no resin is used.

2) 13 g of AlCl ₃ .6H ₂ O was dissolved in 25 ml of water, 1 g of a test resin was added thereto, and the mixture was uniformly mixed to form a gel, and 20 ml of a 28% aqueous ammonia solution was further added. The gel which was initially transparent due to the addition of the aqueous ammonia solution became cloudy. After drying, the gel was placed in an alumina crucible and heated to 1000 ° C. in an argon stream for about 6 hours.
It was heated and baked for hours. The physical properties of the obtained powder were sA: 95 m ^2.
/ G, pre-gelatinization ratio: 41%, but when reheated at 105 ° C. for 5 hours, sA: 19 m ² / g, pre-gelatinization ratio: 99% or more, d
₅₀ : A powder of 0.1 μ was obtained.

3) Boehmite 1.6 g, α-alumina (d
₅₀ : 0.05μ) 20 mg and 0.1 g of 68% nitric acid were added to 18 ml of water to prepare an alumina sol, and 1 g of the resin was added and uniformly mixed to form a gel, which was dried and then placed in an alumina crucible. The temperature was raised to 1000 ° C. in about 6 hours in a stream of argon, and the mixture was heated and calcined for 6 hours. The physical properties of the obtained powder are s
A: 36 (11) m ² / g, pre-gelatinization rate: 91 (80)%, d ₅₀ : 0.
09 (1) μ.

4) 1 g of resin in 7.1 g of 20% SiO ₂ colloid solution
Was added and uniformly mixed to form a gel. After drying, the gel was placed in a silicon carbide crucible, heated to 1500 ° C. in an argon stream for about 7 hours, and baked for about 1 hour. Physical properties of the obtained powder were sA: 9 (5) m ² / g, stationary phase in X-ray diffraction method: β-Si single phase, and d ₅₀ : 0.6 (1) μ.

5) The gel prepared in the same manner as in 3) above was sufficiently kneaded and extruded with a syringe through a needle of about 700 μ to form a thread. After drying, the gel was placed in a muffle furnace heated to 1300 ° C., and placed in air for about 1 hour. Firing for 200 minutes resulted in a 200 μm-thick filamentary alumina.

Use Example 3 In general, the strength of a concrete or mortar product depends on the water-cement ratio of the cement composition. That is, it is known that the strength after casting and hardening increases when the amount of water is reduced as much as possible. However, at actual sites, reducing the amount of water lowers the fluidity of the cement composition, that is, lowers the workability, so there is naturally a lower limit to the water-cement ratio. In order to solve this, a water reducing agent has been used, and although a certain strength can be obtained, it has not yet been satisfied. Excess water of the concrete and mortar composition emerges on the concrete and mortar after casting as breathing water. For this reason, the water-cement ratio of the concrete and the mortar upper part becomes large, and the strength decreases toward the upper part. Also, since the breathing water does not proceed to the next step unless it disappears, the construction period is lengthened.
Therefore, a method has been proposed in which excess water is removed using an absorbent, and the gel that has absorbed water gradually releases water inside the concrete to perform internal wet curing, but currently commercially available water absorbents have an ionic component, particularly calcium. Since it hardly absorbs an aqueous solution containing polyvalent ion components such as ions, a sufficient effect cannot be exhibited. However, as apparent from the absorption performance table, the resin of the present invention absorbs even a saturated aqueous solution of calcium hydroxide, which is a main component of cement, and can be used as described above.

Further, the cement composition containing the resin of the present invention hardly causes rapid dryout at the time of hardening, prevents the occurrence of cracks by the effect of moist curing, increases the strength, and reduces the dimensional change rate. improves. In addition to the method of mixing with the concrete and mortar composition, there is also a method of preparing an absorbent sheet using the resin of the present invention and covering the concrete and mortar after casting. In this method, the strength is increased by the wet curing effect because the absorbent sheet absorbs the breathing water and is in close contact with the casting surface.

Further, by curing the mortar composition containing the resin of the present invention, the gelled portions remain as voids, and as a result, the density of the mortar can be reduced (the weight of the mortar can be reduced). Incidentally, currently available water-absorbing agents hardly absorb an aqueous solution containing a polyvalent ion component, and therefore have few voids in the mortar and are difficult to use as described above. In any case, the effect is exhibited by using the resin of the present invention having an ability to absorb a saturated calcium hydroxide aqueous solution.

1) A resin to be tested for a concrete composition containing 300 kg of ordinary Portland cement (manufactured by Nippon Cement), 225 kg of tap water, 670.6 kg of fine aggregate and 1031.1 kg of coarse aggregate
(A), (B) and (C) were mixed together in an amount of 600 g. Except that the kneading time is 4 minutes, it is manufactured in accordance with JISA 1138 "How to make concrete in a test room", the amount of breathing and the breathing rate are measured in accordance with JIS A 1123, and the compressive strength in accordance with JIS A 1108. Measured. Table 11 shows the results.

Test resin: A) Crosslinked product of poly N-vinylacetamide (average degree of polymerization of main chain; about 20,000, crosslinking agent: N, N'-methylenebisacrylamide, crosslinking density; about 1/350) B) Poly N -Crosslinked vinylacetamide / sodium acrylate (monomer molar ratio; 50/50, average main chain degree of polymerization; approx.
20,000, crosslinker; N, N'-methylenebisacrylamide, crosslink density: about 1/350) C) Table 11 shows the results when no commercially available water-absorbent resin "Sumikagel S-50" was added. Also described.

[0118]

[Table 11]

By incorporating the resin of the present invention, the breathing was clearly reduced and the compressive strength was improved.

2) A mortar composition containing 3000 g of ordinary Portland cement (manufactured by Nippon Cement), 1500 g of tap water and 6000 g of fine aggregate was mixed with 6.0 g of each of the test resins (A), (B) and (C). Knead, length change rate is JIS A 1129
It measured based on. Table 12 shows the results.

Test resin: A) Crosslinked product of poly N-vinylacetamide (average degree of polymerization of main chain: about 20,000, crosslinking agent: N, N'-methylenebisacrylamide, crosslinking density: about 1/350) B) Poly N -Crosslinked vinylacetamide / sodium acrylate (monomer molar ratio; 50/50, average main chain degree of polymerization; approx.
20,000, crosslinker; N, N'-methylenebisacrylamide, crosslink density: about 1/350) C) Table 12 shows the results when no commercially available water-absorbent resin "Sumikagel S-50" was added. Also described.

[0122]

[Table 12]

By incorporating the resin of the present invention, the rate of change in length was clearly reduced.

3) The test resins (A), (B) and (C) were uniformly spread at 26.5 g / m ² on the non-woven fabric, respectively, and the non-woven fabric was placed thereon. This absorbent sheet is placed on the concrete after casting to produce a test specimen. The mix of this concrete is ordinary Portland cement (Nippon Cement) 3
00 kg / m ³ , tap water 225 kg / m ³ , fine aggregate 670.6 kg / m
³ and 1031.1 kg / m ³ of coarse aggregate, and were prepared according to JIS A 1138. The specimen was removed from the mold on 7 days of age and the absorbent sheet was left as it was, and the compressive strength of 28 days and 91 days of age was JIS A 11
It was measured according to 08. Table 13 shows the results.

Test resin: A) Crosslinked product of poly N-vinylacetamide (average degree of polymerization of main chain; about 20,000, crosslinking agent: N, N'-methylenebisacrylamide, crosslinking density; about 1/350) B) Poly N -Crosslinked vinylacetamide / sodium acrylate (monomer molar ratio; 50/50, average main chain degree of polymerization; approx.
20,000, crosslinking agent; N, N'-methylenebisacrylamide, crosslinking density: about 1/350) C) Commercially available water-absorbing resin "Sumikagel S-50" Table 13 shows the results when no resin was added as Comparative Example 1. Also described.

[0126]

[Table 13]

The absorbent sheet made by using the resin of the present invention clearly improved the compressive strength.

4) A mortar composition containing 3000 g of ordinary Portland cement (manufactured by Nippon Cement), 1500 g of tap water and 6000 g of fine aggregate was kneaded with 12 g of each of the test resins (A), (B) and (C). Then, the density on the 7th day was measured. Table 14 shows the results.

Test resin: A) Crosslinked product of poly N-vinylacetamide (average degree of polymerization of main chain; about 20,000, crosslinking agent: N, N'-methylenebisacrylamide, crosslinking density; about 1/350) B) Poly N -Crosslinked vinylacetamide / sodium acrylate (monomer molar ratio; 50/50, average main chain degree of polymerization; approx.
20,000, crosslinker; N, N'-methylenebisacrylamide, crosslink density: about 1/350) C) Table 14 shows the results when no commercially available water-absorbent resin "Sumikagel S-50" was added. Also described.

[0130]

[Table 14]

By mixing the absorbent of the present invention, the weight of the mortar was clearly reduced.

Use Example 4 The absorption of the resin of the present invention does not significantly decrease even in an aqueous solution containing a large amount of calcium ions. Therefore, the desiccant containing the resin of the present invention absorbs a large amount of calcium chloride deliquescent resulting from moisture absorption, and the entire desiccant becomes non-fluidized due to gelling of the resin. As a result, there is no contamination of other substances. Incidentally, a so-called water-absorbing resin which has been conventionally commercially available is not suitable for the above-mentioned applications because the water absorption of an aqueous solution containing polyvalent ions such as calcium ions is extremely reduced. A typical example is shown below.

5 g, 10 g and 50 g of the resin (A) of the present invention were added to 100 g of the pulverized calcium chloride (200 MESH passed product), and the mixture was mechanically mixed with each other to obtain a desiccant 1, 2 and 3 respectively.
I got Calcium chloride crushed product (200MESH passed product) 1
10 g of the resin (B) of the present invention was added to 00 g and mechanically mixed to obtain a hygroscopic agent 4. Ground calcium chloride (200MESH
50 g of the resin (C) was added to 100 g of the passed product, and the mixture was mechanically mixed to obtain a hygroscopic agent 5. Ground calcium chloride (200MES
H-passed product) was used alone as the moisture absorbent 6.

Each of 50 g of the hygroscopic agent obtained by the above preparation was left in a thermo-hygrostat (temperature: 30 ° C., humidity: 95%). Table 15 shows the results.

Test resin: A) Cross-linked poly N-vinylacetamide (average degree of polymerization of main chain; about 20,000, cross-linking agent: N, N'-methylenebisacrylamide, cross-link density: about 1/350) B) Poly N -Crosslinked vinylacetamide / sodium acrylate (monomer molar ratio; 50/50, average main chain degree of polymerization; approx.
20,000, crosslinking agent: N, N'-methylenebisacrylamide, crosslinking density: about 1/350) C) Commercially available water-absorbing resin "Diawet S-II"

[0136]

[Table 15]

By adding the resin of the present invention, the fluidity of the hygroscopic agent was apparently lost.

Use Example 5 The resin of the present invention can be used for sanitary articles such as disposable diapers and napkins since the water absorption rate hardly decreases even for body fluids (urine and menses) containing a large amount of salts. Conventionally commercially available so-called water-absorbent resin, the disposable diaper containing the resin of the present invention has a large urine water absorption capacity, as a result, the amount of resin required to absorb the same amount of urine can be reduced, It can be said that the bodily fluid absorbent is more suitable for the above uses. The basic form of sanitary goods is 1. 1. liquid permeable surface sheet; Absorbing layer (polymer absorber,
2. cotton-like pulp, etc.); It is a breathable waterproof sheet. Among them, the resin of the present invention is used for the absorption layer. There are many shapes of the absorbing layer, but typical ones are those in which a resin is sprayed on a nonwoven fabric, and those in which a resin is sandwiched between nonwoven fabrics. Absorption capacity was measured in a form close to these. The method for measuring the water absorption capacity is shown below.

0.4 g of each of the test resins (A), (B), (C) and (D) was evenly spread on a 165 × 60 mm tissue paper, and one more tissue paper was placed thereon. ,
Spray water with light pressure (spray amount is appropriate). Press down with an embossing roller heated to about 140 ° C. 80 ° C due to insufficient drying of the emboss roller alone
For 2 hours under vacuum. This sheet is placed on a wire mesh and immersed in artificial urine at a liquid temperature of 30 ° C. After 1 hour, the sheet is taken out together with the wire net, tilted at 45 °, drained for 1 minute, and weighed. Table 16 shows the results.

Test resin: A) Crosslinked product of poly N-vinylacetamide (average degree of main chain polymerization: about 20,000, crosslinking agent: N, N'-methylenebisacrylamide, crosslinking density: about 1/350) B) Poly N -Crosslinked vinylacetamide / sodium acrylate (monomer molar ratio; 50/50, average main chain degree of polymerization; approx.
20,000, crosslinking agent: N, N'-methylenebisacrylamide, crosslinking density: about 1/350) C) Commercially available water-absorbent resin "Sumikagel S-50" D) Commercially available water-absorbent resin "Diawet S-II"

[0141]

[Table 16]

──────────────────────────────────────────────────続 き Continuation of front page (51) Int.Cl. ⁷ Identification code FI A61L 15/00 A61L 15/00 B01F 17/00 B01F 17/00 C04B 24/24 C04B 24/24 Z 40/00 40/00 C08F 26/02 C08F 26/02 C09K 17/00 C09K 17/00 Z // A47K 11/06 A47K 11/06 (56) References JP-A-58-5305 (JP, A) JP-A-3-227310 (JP) , A) Patent 2947637 (JP, B2) (58) Fields investigated (Int. Cl. ⁷ , DB name) B01J 20/00-20/34 C04B 24/24 C08F 26/02

Claims (16)

(57) [Claims] 1. A homopolymer comprising a repeating unit represented by the following general formula (A) or a copolymer comprising a repeating unit represented by the general formulas (A) and (B): Embedded image [Wherein, R ¹ , R ² and R ³ each independently represent a hydrogen atom or a methyl group, X is a group —COOY (wherein Y is a hydrogen atom,
An alkali metal, a C _{1 to} C ₆ alkyl group or a lower alkyl group substituted with a hydroxyl group, a dialkylamino group or a quaternary ammonium group, a group —CONHZ (wherein Z
Represents a hydrogen atom or a dialkylamino group, a quaternary ammonium group, a lower alkyl group substituted by sulfonic acid or an alkali metal salt thereof), a cyano group, a 2-ketopyrrolidinyl group, a lower alkoxy group, a lower acyl group, a lower acyloxy group A lower alkyl group substituted with a group or a sulfonic acid or an alkali metal salt thereof, when R ³ is a methyl group, X is a cyano group, a 2-ketopyrrolidinyl group, a lower alkoxy group, a lower acyl group, a lower acyloxy group and Not a lower alkyl group substituted with a sulfonic acid or a salt thereof, M represents a hydrogen atom, an ammonium group or an alkali metal, and p represents 0 or 1], and a main chain represented by the following general formula (C): Embedded image [Wherein, R ⁴ represents a hydrogen atom or a methyl group, R ⁵ represents an alkylene group having 3 to 10 carbon atoms , — (CH ₂ .CHR ⁶ .O ) _n —CH
₂ · CHR ⁶ — (wherein, R ⁶ represents a hydrogen atom or a methyl group, and n represents an integer of 1 to 4) or a group represented by the following formula (D): (Wherein m represents 0 or 4)] as a main component is a crosslinked N-vinylcarboxylic acid amide resin obtained by crosslinking with a crosslinking agent excluding a bis (N-vinylcarboxylic acid amide) compound , A liquid absorbent for vegetation or as an agent for retaining (supplying) artificial media. 2. A homopolymer comprising a repeating unit represented by the following general formula (A) or a copolymer comprising a repeating unit represented by the general formula (A) and the general formula (B): Embedded image [Wherein, R ¹ , R ² and R ³ each independently represent a hydrogen atom or a methyl group, X is a group —COOY (wherein Y is a hydrogen atom,
An alkali metal, a C _{1 to} C ₆ alkyl group or a lower alkyl group substituted with a hydroxyl group, a dialkylamino group or a quaternary ammonium group, a group —CONHZ (wherein Z
Represents a hydrogen atom or a dialkylamino group, a quaternary ammonium group, a lower alkyl group substituted by sulfonic acid or an alkali metal salt thereof), a cyano group, a 2-ketopyrrolidinyl group, a lower alkoxy group, a lower acyl group, a lower acyloxy group A lower alkyl group substituted with a group or a sulfonic acid or an alkali metal salt thereof, when R ³ is a methyl group, X is a cyano group, a 2-ketopyrrolidinyl group, a lower alkoxy group, a lower acyl group, a lower acyloxy group and Not a lower alkyl group substituted with a sulfonic acid or a salt thereof, M represents a hydrogen atom, an ammonium group or an alkali metal, and p represents 0 or 1], and a main chain represented by the following general formula (C): Embedded image [Wherein, R ⁴ represents a hydrogen atom or a methyl group, R ⁵ represents an alkylene group having 3 to 10 carbon atoms , — (CH ₂ .CHR ⁶ .O ) _n —CH
₂ · CHR ⁶ — (wherein, R ⁶ represents a hydrogen atom or a methyl group, and n represents an integer of 1 to 4) or a group represented by the following formula (D): (Wherein m represents 0 or 4)] as a main component is a crosslinked N-vinylcarboxylic acid amide resin obtained by crosslinking with a crosslinking agent excluding a bis (N-vinylcarboxylic acid amide) compound , A liquid absorbent as an absorbent for water containing calcium. 3. The liquid absorbent according to claim 2, which is used as a concrete curing agent, a cement modifier, or a moisture absorbent. 4. A homopolymer comprising a repeating unit represented by the following general formula (A) or a copolymer comprising a repeating unit represented by the general formula (A) and the general formula (B): Embedded image [Wherein, R ¹ , R ² and R ³ each independently represent a hydrogen atom or a methyl group, X is a group —COOY (wherein Y is a hydrogen atom,
An alkali metal, a C _{1 to} C ₆ alkyl group or a lower alkyl group substituted with a hydroxyl group, a dialkylamino group or a quaternary ammonium group, a group —CONHZ (wherein Z
Represents a hydrogen atom or a dialkylamino group, a quaternary ammonium group, a lower alkyl group substituted by sulfonic acid or an alkali metal salt thereof), a cyano group, a 2-ketopyrrolidinyl group, a lower alkoxy group, a lower acyl group, a lower acyloxy group A lower alkyl group substituted with a group or a sulfonic acid or an alkali metal salt thereof, when R ³ is a methyl group, X is a cyano group, a 2-ketopyrrolidinyl group, a lower alkoxy group, a lower acyl group, a lower acyloxy group and Not a lower alkyl group substituted with a sulfonic acid or a salt thereof, M represents a hydrogen atom, an ammonium group or an alkali metal, and p represents 0 or 1], and a main chain represented by the following general formula (C): Embedded image [Wherein, R ⁴ represents a hydrogen atom or a methyl group, R ⁵ represents an alkylene group having 3 to 10 carbon atoms , — (CH ₂ .CHR ⁶ .O ) _n —CH
₂ · CHR ⁶ — (wherein, R ⁶ represents a hydrogen atom or a methyl group, and n represents an integer of 1 to 4) or a group represented by the following formula (D): (Wherein m represents 0 or 4)] as a main component is a crosslinked N-vinylcarboxylic acid amide resin obtained by crosslinking with a crosslinking agent excluding a bis (N-vinylcarboxylic acid amide) compound And a liquid absorbent as a dispersant for a metal salt solution (complex forming agent with a metal compound). 5. A composition wherein the molar ratio of component (A) to component (B) in the main chain is 50-100: 50-0, the average degree of polymerization is 100-500,000, and the crosslink density is 1 / 10-1 / 500,000. Claim 1 which is a range
5. The liquid absorbent according to any one of 4. 6. A liquid absorption according to any one of claims 1 to 5 as a solvent polarity parameter E _T value of 45 or more single organic solvents or E _T value of 53 or more mixed organic solvents absorbent Agent. 7. A homopolymer comprising a repeating unit represented by the following general formula (A) or a copolymer comprising a repeating unit represented by the general formulas (A) and (B): Embedded image [Wherein, R ¹ , R ² and R ³ each independently represent a hydrogen atom or a methyl group, X is a group —COOY (wherein Y is a hydrogen atom,
An alkali metal, a C _{1 to} C ₆ alkyl group or a lower alkyl group substituted with a hydroxyl group, a dialkylamino group or a quaternary ammonium group, a group —CONHZ (wherein Z
Represents a hydrogen atom or a dialkylamino group, a quaternary ammonium group, a lower alkyl group substituted by sulfonic acid or an alkali metal salt thereof), a cyano group, a 2-ketopyrrolidinyl group, a lower alkoxy group, a lower acyl group, a lower acyloxy group A lower alkyl group substituted with a group or a sulfonic acid or an alkali metal salt thereof, when R ³ is a methyl group, X is a cyano group, a 2-ketopyrrolidinyl group, a lower alkoxy group, a lower acyl group, a lower acyloxy group and Not a lower alkyl group substituted with a sulfonic acid or a salt thereof, M represents a hydrogen atom, an ammonium group or an alkali metal, and p represents 0 or 1], and a main chain represented by the following general formula (C): Embedded image [Wherein, R ⁴ represents a hydrogen atom or a methyl group, R ⁵ represents an alkylene group having 3 to 10 carbon atoms , — (CH ₂ .CHR ⁶ .O ) _n —CH
₂ · CHR ⁶ — (wherein, R ⁶ represents a hydrogen atom or a methyl group, and n represents an integer of 1 to 4) or a group represented by the following formula (D): Wherein, in the formula, m represents 0 or 4), a crosslinked N-vinylcarboxylic acid amide resin obtained by crosslinking with a crosslinking agent excluding a bis (N-vinylcarboxylic acid amide) compound, solvent polarity parameter E _T value liquid absorbent is 45 or more single organic solvents or E _T value of 53 or more absorbers mixed organic solvent. 8. The composition according to claim 1, wherein the molar ratio of component (A) to component (B) in the main chain is 50-100: 50-0, the average degree of polymerization is 100-500,000, and the crosslink density is 1 / 10-1 / 500,000. The liquid absorbent according to claim 7, which is in a range. 9. The liquid absorbent according to claim 7, which is used as a dispersant for a metal salt solution (complex forming agent with a metal compound). 10. A homopolymer comprising a repeating unit represented by the following general formula (A) or a copolymer comprising a repeating unit represented by the general formula (A) and the general formula (B): Embedded image [Wherein, R ¹ , R ² and R ³ each independently represent a hydrogen atom or a methyl group, X is a group —COOY (wherein Y is a hydrogen atom,
An alkali metal, a C _{1 to} C ₆ alkyl group or a lower alkyl group substituted with a hydroxyl group, a dialkylamino group or a quaternary ammonium group, a group —CONHZ (wherein Z
Represents a hydrogen atom or a dialkylamino group, a quaternary ammonium group, a lower alkyl group substituted by sulfonic acid or an alkali metal salt thereof), a cyano group, a 2-ketopyrrolidinyl group, a lower alkoxy group, a lower acyl group, a lower acyloxy group A lower alkyl group substituted with a group or a sulfonic acid or an alkali metal salt thereof, when R ³ is a methyl group, X is a cyano group, a 2-ketopyrrolidinyl group, a lower alkoxy group, a lower acyl group, a lower acyloxy group and Not a lower alkyl group substituted with a sulfonic acid or a salt thereof, M represents a hydrogen atom, an ammonium group or an alkali metal, and p represents 0 or 1], and a main chain represented by the following general formula (C): Embedded image [Wherein, R ⁴ represents a hydrogen atom or a methyl group, R ⁵ represents an alkylene group having 3 to 10 carbon atoms , — (CH ₂ .CHR ⁶ .O ) _n —CH
₂ · CHR ⁶ - (wherein, R ⁶ represents a hydrogen atom or a methyl group, n is an integer of 1 to 4) or a group [Formula 20] of the following formula (D) Wherein, in the formula, m represents 0 or 4), a crosslinked N-vinylcarboxylic acid amide resin obtained by crosslinking with a crosslinking agent excluding a bis (N-vinylcarboxylic acid amide) compound, The molar ratio of component (A) to component (B) in the main chain is 50 to 1
00: 50 to 0, a liquid absorbent having an average degree of polymerization of 100 to 500,000 and a crosslink density of 1/10 to 1 / 500,000. 11. Liquid absorbing agent according to claim 10 which is a solvent polarity parameter E _T value of 45 or more single organic solvents or E _T value of 53 or more mixed organic solvents of the absorbent. 12. The liquid absorbent according to claim 10, which is used as a liquid for preserving or supplying an artificial medium to a plant material. 13. The liquid absorbent according to claim 10, which is used as a body fluid absorbent for hygiene articles. 14. The liquid absorbent according to claim 10, which is used as an absorbent for water containing calcium. 15. The liquid absorbent according to claim 14, which is used as a concrete curing agent, a cement modifier, or a moisture absorbent. 16. The liquid absorbent according to claim 10, which is used as a dispersant for a metal salt solution (complex forming agent with a metal compound).