CS277398B6 - Process for extracting water from aqueous macromolecular solutions or emulsions - Google Patents

Abstract

PURPOSE:The title resin having a peculiar property of separating and retaining water and being useful for the concentration control of bacteria, enzymes, or the like, prepared by water-insolubilizing a specified N-alkyl- or N-alkylene-substituted (meth)acrylamide polymer. CONSTITUTION:A (co)polymer obtained by (co)polymerizing an N-alkyl- or N- alkylene-substituted (meth)acrylamide monomer of formula I or II [wherein R1 is H or methyl, R2 is H, methyl, or ethyl, R3 is methyl, ethyl, or propyl, A is -(CH2)n or -(CH2)2-O-(CH2)2-, and n is 4-6] with, optionally, other copolymerizable monomers (e.g., acrylamide) in the presence of a polymerization initiator (e.g., ammonium persulfate) is water-insolubilized by heating to 60-250 deg.C.

Description

The present invention relates to a process for extracting water from aqueous macromolecular solutions or emulsions by means of a composition having the ability to absorb water as a function of temperature, which composition is capable of absorbing and retaining water at normal temperature and, when heated. able to shrink even in the presence of a large excess of water while releasing the already absorbed water.

Separation of water from a variety of environments is commonly practiced in practice such as, for example, concentrating aqueous solutions, crystallizing from aqueous solutions, producing pure water, and the like.

In particular, the following specific methods are used in the practical implementation of these procedures:

- water separation using membranes such as reverse osmosis membranes, ultrafiltration membranes and the like, and

water separation using phase water change, such as multistage flash distillation or lyophilization processes.

All these methods have found common industrial use. However, it should be noted that none of these methods is entirely satisfactory. For this reason, research has focused on improving these practices.

With the advancement of the invention, it has been proposed to use resinous substances which are capable of absorbing and retaining water in their structure in an amount which is several hundred times greater than the weight of these substances. These resins are commonly referred to as highly absorbent or superabsorbent resins and are currently being tested in a variety of applications. However, the use of these resins has the following problems:

- after water absorption, the above resins can only be regenerated by heating, removing the absorbed water. Where recovery and re-use of these resins are considered, considerable costs for such recovery must be incurred;

the amount of water that the above resins can absorb depends on whether the water is in a pure state or whether salts are present in the water. This amount usually decreases when the water contains salts and in some cases the absorbed amount of water is so small that it is one twentieth of the amount of water that can be absorbed from the pure water environment;

After absorbing water, the abovementioned prior art resins are not entirely acceptable in terms of dynamic characteristics, especially in terms of their ability to retain their shape at a given capacity.

In addition, various physical properties of different water retention gels were determined. The results of these measurements revealed that the amount of water in the water retention gel was temperature-dependent at equilibrium (see: Journal of Polymer Science, Polymer Symposium 66, pp. 209-219, 1979; European Polymer Journal 17, pp. 361-36). 366 (1981); Polymer Bulletin 7: 107-113 (1982). From the results of these investigations it can be concluded that there is a possibility to develop a method of water separation in which these gels would be used at different temperatures. In practice, however, the degree of swelling of these gels at low temperatures is not as great as the data in the above references. In addition, the differences in absorption capacity at different temperatures are not large enough. Furthermore, it has not yet been determined how quickly these gels are able to swell or shrink when their temperature changes. Of course, these substances undergo rapid swelling or shrinking very unevenly as temperatures change.

It is an object of the present invention to provide a method of separating water from aqueous solutions by means of a means which avoids the disadvantages of the prior art processes and means and which is energy efficient.

The method of extracting water from the aqueous macromolecular solutions or emulsions of the present invention comprises contacting the aqueous solution or emulsion with a water absorbing and releasing agent, said composition being a water-insoluble resin representing at least a polymer of one monomer selected from from the group of N-alkyl-substituted or N-alkylene-substituted acrylamides or methacrylamides represented by the following general formula I:

in which it means

R ¹ and R ² individually are hydrogen or methyl, and

R ³ is methyl, ethyl or propyl, with the proviso that R ³ is ethyl or propyl when R ² is hydrogen and R ³ is methyl or ethyl if wherein R < ² > is methyl, or R < ² > and R < ³ &^gt; taken together form a group or group

^CH2 -) - ^CI12 or a copolymer of at least one monomer selected from the group of said acrylamides or methacrylamides and one or more other copolymerizable monomers selected from the group of hydrophilic monomers including hydroxyethyl methacrylate, hydroxyethyl acrylate, acrylamide and N-vinyl-2-pyrrolidone, from the group ionic monomers including sodium 2-acrylamido-2-phenyl-propanesulfonate, 2-acrylamido-2-methylpropanesulfonic acid, Ν, Ν-dimethylaminopropylmethacrylamide, acrylic acid and methacrylic acid, and from the group of hydrophobic monomers including methyl methacryrene, acrylonitrile, acrylonitrile, acrylonitrile, acrylonitrile, butylacrylamide, Nn-hexylacrylamide and ethyl acrylate, wherein the weight of the absorbed water is in the range of eight to 100 times the weight of water. of this composition at an ambient temperature of 25 [deg.] C and a wt. the absorbed water ranges from 1 to 20 times by weight. at the transition point of the agent corresponding to the temperature at which the agent stops shrinking, and then the absorbed water composition contracts to release the absorbed water even in the presence of a large excess of water.

An essential advantage of the process of the present invention is that the polymer or copolymer of said acrylamide or methacrylamide derivative is capable of absorbing water and thus swelling at normal temperature while being able to shrink even when heated in the presence of a large excess of water and release retained water. The absorbent capacity of these compositions varies widely, depending on temperature changes, and the change in absorbent capacity is rapid enough. The composition used in the process is readily recoverable and reusable. Further, the absorption capacity of the composition does not decrease much with the presence of inorganic salts that are present in the aqueous solution being treated. In carrying out the process of the invention, the composition has the ability to retain its shape at a given capacity even after water absorption. Last but not least, a considerable advantage of the process according to the invention is the very low energy consumption. It may also be noted in this context that the process of the invention is applicable to aqueous solutions containing thermal susceptible substances.

Preferably, the process of the invention is carried out by adding said composition to an aqueous solution or emulsion, and after absorbing water, separating the water-containing composition from the aqueous solution or emulsion and exposing it to the atmosphere above the transition point of said agent. from said reagent which is recycled.

The polymer or copolymer that is converted to the insoluble form used in the process of the invention usually has the property that when the aqueous solution of the substance is heated, it becomes hydrophobic, resulting in cloudiness of the solution. However, a polymer or copolymer used in the process of the invention that is converted to an insoluble form need not necessarily be limited to the polymer or copolymer exhibiting this property. Any polymer or copolymer may be used according to the present invention, provided that it meets the condition that the absorbency of the material varies with temperature. These polymers or copolymers have amphophilic properties. This means that they are insoluble to a wide extent, which means that they exhibit both hydrophilic and hydrophobic properties so that they can be dissolved not only in water but also in organic solvents such as benzene.

Examples of the above-mentioned polymers or copolymers include the following polymers and copolymers of at least one of the following N-alkyl- or N-alkylene-substituted acrylamides and methacrylamides:

Amide Cloud point of the corresponding polymer (° C)

N-n-propyl acrylamide 32

N-n-propylmethacrylamide and N-isopropylacrylamide 29

N-isopropylmethacrylamide

N-ethyl acrylamide

N-ethyl methacrylamide

N, N-dimethylacrylamide

N, N-dimethylmethacrylamide

N-methyl-N-ethyl acrylamide

N-methyl-N-ethylmethacrylamide

N-acryloylpyrrolidine 51

N-methacryloylpyrrolidine

N-acryloylmorpholine

N-methacryloylmorpholine

From the above data and from the foregoing, it is apparent that the following resins obtained by converting polymers or copolymers to insoluble form derived from the following monomers are not preferred in terms of swelling characteristics for the purposes of the process of the invention:

- N-monoalkylsubstituované acrylamides and methacrylamides, especially compounds of the formula I in which R ² and R ³ are hydrogen and alkyl, wherein the alkyl group contains 4 or more carbon atoms, such as N-butylacrylamide or N-butylmethacrylamide,

- Ν, Ν-dialkylsubstituted acrylamides and methacrylamides, in particular N-methyl-N-propyl acrylamide or N-methyl-N-propylmethacrylamide of the general formula I, in which R ² and R ³ are methyl and propyl; formula I wherein the total number of carbon atoms in each of the alkyl groups is 4 or more, such as Ν, Ν-diethyl acrylamide or, Ν, Ν-diethylmethacrylamide, and

- N-alkylene-substituted acrylamides or methacrylamides, in particular those represented by the general formula I, in which the substituents R ² and R ³ form a - (CH ₂ ) _n - group, such as

N-acryloylpiperidine or N-methacryloylpiperidine wherein n is 5 or more.

In addition, one or more monomers selected from the group consisting of hydrophilic monomers, ionic monomers, hydrophobic monomers, etc. may be additionally copolymerized to control the amount of water to be absorbed and to improve the shape retention at a given capacity of the resin in which water is absorbed.

Examples of hydrophilic monomers include: acrylamide, methacrylamide, N-methyl acrylamide, N-methylmethacrylamide, diacetone acrylate, hydroxyethyl methacrylate, hydroxyethyl acrylate, hydroxypropyl methacrylate, hydroxypropylacrylate, various methoxypolyethylene glycol methacrylate, N-methyl acrylate, N-methyl acrylate; other similar substances. In this connection, vinyl acetate, glycidyl methacrylate and the like can be introduced into the resin by copolymerization followed by hydrolysis of the materials to render the final product hydrophilic.

By way of illustration, examples of the above ionic monomers include acids such as acrylic acid, methacrylic acid, vinyl sulfonic acid, allylsulfonic acid, methalylsulfonic acid, styrene sulfonic acid, 2-acrylamido-2-phenylpropanesulfonic acid, acid

2-acrylamido-2-methylpropanesulfonic acid and the like and salts thereof; furthermore amines such as N, N-dimethylaminoethyl methacrylate, N, N-diethylaminoethyl methacrylate, Ν, N-dimethylaminoethyl acrylate, Ν, N-dimethylaminopropylmethacrylamide, N, N dimethylaminopropylacrylamide and the like and the like, and the like. it is also possible to achieve ionic character by introducing various acrylates, methacrylates, acrylamides, methacrylamide, acrylonitrile or the like by copolymerization and then subsequent hydrolysis of the introduced portions.

By way of illustration, examples of hydrophobic monomers include N-alkyl acrylamide derivatives and N-alkyl methacrylamide derivatives such as: Nn-butyl acrylamide, Nn-butylmethacrylamide, N-tert-butyl acrylamide, N-tert-butylmethacrylamide, N, N- diethylacrylamide, Ν, Ν-diethylmethacrylamide, N-acryloyl piperidine, N-methacryloylpiperidine, Nn-hexylacrylamide, Nn-hexylmethacrylamide, Nn-octyl acrylamide, Nn-octylmethacrylamide, N-tert-octylacrylamide, dodecrylamide, dodecrylamide substances; further N- ((N-glycidoxyalkyl) acrylamide derivatives and N- ((N-glycidoxyalkyl) methacrylamide derivatives such as Ν, dig-diglycidylacrylamide, N, N-diglycidylmethacrylamide, N- (4-glycidoxybutyl) acrylamide, N- (4-glycidoxybutyl) methacrylamide, N- (5-glycidoxypentyl) acrylamide, N- (6-glycidoxyhexyl) acrylamide and the like; ethylhexyl methacrylate, glycidyl methacrylate and the like, acrylonitrile, methacrylonitrile, vinyl acetate, vinyl chloride, olefins such as ethylene, propylene, butene and the like, styrene, α-methylstyrene, butadiene, isoprene, etc.

A suitable proportion of the hydrophilic, ionic or hydrophobic monomer in the acrylamide or methacrylamide derivative of the formula I can vary within wide limits depending on the combination of the acrylamide derivative and the methacrylamide derivative and on the above monomer. While it is not possible to provide a generally applicable ratio for each combination, it is generally stated that the hydrophilic, ionic and hydrophobic monomers can be used in amounts (respectively) of 60% by weight. % or less, 30 wt. % or less and 60 wt. or less.

With regard to the process of converting a polymer of the above monomer into an insoluble form in water, it can be said that the polymer can be converted to an insoluble form in water either during its polymerization or it is subjected to a post-polymerization post-polymerization. The following methods may be used as a particular process for converting a polymer to an insoluble form:

(1) copolymerization of a crosslinkable monomer containing at least two double bonds per molecule with the above-mentioned acrylamide or methacrylamide derivative;

2) copolymerization of the polymer with an N-alkoxymethylmethacrylamide derivative,

3) increasing the ratio of the above hydrophobic monomer and its copolymerization with an acrylamide or methacrylamide derivative,

4) polymerizing said polymer by a block polymerization method,

5) subjecting the polymer to heat treatment,

(6) combining the polymer with a water-insoluble fibrous material such as cellulose or the like;

7) when the polymer contains hydroxyl groups, amino groups or the like, these groups can be reacted with a polyfunctional substance, such as epichlorohydrin or the like, to convert the polymer into an insoluble form;

8) copolymerization of a monomer of the formula I with a monomer containing at least one substituent group containing at least one active hydrogen, such as a carboxyl group, a sulfo group or a hydroxyl group, or preparing a polymer complex from the monomer shown in the above general formula and the polymer of the monomer in the form of a polymer complex, thereby converting the polymer into an insoluble form.

The above processes of converting a polymer to an insoluble form will be described in detail below.

For example, the following crosslinking monomers may be used in the first method: Ν, Ν'-methylenebisacrylamide, Ν, Ν-diallylacrylamide, triacrylformaldehyde, N, N-diacryloylimide,

Ν, Ν-dimethacryloylimide, ethylene glycol acrylate, ethylene glycol dimethacrylate, various polyethylene glycol dimethacrylates, various polyethylene glycol dimethacrylates, propylene glycol dimethacrylate, propylene glycol dimethacrylate, various polypropylene glycol dimethacrylates, 1,3-polypropylene glycol dimethacrylates, various 1,3-ethylene glycol dimethacrylates

1,3-butyleneglycol, 1,4-butyleneglycol, glycerine, neopentylglycol, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, trimethylolethantrimethakrylát, trimethylolethantriakrylát, tetramethylolmethantetramethakryiát, tetramethylolmethantriakrylát, divinylbenzene, diallyl phthalate, etc. The proportion of each of said crosslinking monomer to the above an acrylamide derivative can vary a wide range depending on the combination of the acrylamide derivative and the crosslinking monomer, as well as the desired degree of crosslinking. Although it is not possible to define a generally applicable amount of the crosslinking agent, it should be noted that these crosslinking monomers may generally be used in amounts ranging from 0.01 to 10% by weight.

• λ.

The N-alkoxymethylmethacrylamide derivatives used in the second method include N-hydroxymethylmethacrylamides. In particular, N-methylolmethacrylamides, N-methoxymethylmethacrylamides, N-ethoxymethylmethacrylamides, N-n-butoxymethylmethacrylamides, N-tert-butoxymethylmethacrylamides and other similar substances which can be used in this process are preferred. The proportion of each of said N-alkoxymethylmethacrylamide derivatives to the amount of the above acrylamide derivative may vary within wide limits depending on the combination of the acrylamide derivative and the N-alkoxymethylmethacrylamide derivative. While it is not possible to define the amount used for each combination, it is to be understood that the N-alkoxymethylmethacrylamide derivatives may be used in general in amounts ranging from 0.01 to 30% by weight.

In carrying out the aforementioned third method, the ratio of hydrophobic monomer to acrylamide or methacrylamide derivative having an amphophilic nature may vary within wide limits depending on the combination of said acrylamide or methacrylamide derivative and hydrophobic monomer. Although not meant to be a definitive limitation, it may be noted that the proportion of hydrophobic monomer may generally be 1% by weight. % or more, preferably 3 wt. or more. In this case, the copolymerization can be carried out by any desired copolymerization method, either by block copolymerization or graft copolymerization.

In the fourth method, the polymerization is carried out by a block polymerization method. The polymerization can be practiced by polymerizing the monomer as it is without diluting the monomer to obtain a polymer in block or suspending the monomer in the solvent and then polymerizing the monomer in droplet form to obtain a granular polymer. .

In carrying out said fifth method, the polymer is subjected to a heat treatment. The heat treatment conditions vary depending on the polymer used and do not remain constant. In general, however, the polymer obtained by block polymerization, slurry polymerization, solvent polymerization or the like can be heat treated generally at a temperature in the range of from 60 to 250 ° C or preferably at a temperature in the range of from 80 to 200 ° C. Noc: 2 ° C. When the polymer is obtained by a solvent polymerization method, the polymer may be heat treated simultaneously with drying the polymer, particularly by distilling off the solvent.

According to the sixth method above, the polymer is bonded to a fibrous material or the like. The acrylamide or methacrylamide derivative thus formed may be polymerized by impregnation or may be polymerized by a graft polymerization process to a fibrous material such as natural or synthetic fibers such as cellulose fibers, nylon fibers, polyester fibers, acrylic fibers and the like, or a nonwoven fabric made of polypropylene, ethylene-propylene copolymer or the like, or a water-insoluble porous material such as silica, alumina, can also be used. zeolite and the like. Alternatively, the fibrous or porous material may be impregnated with the above polymer.

In carrying out the seventh method, a polyfunctional compound, such as epichlorohydrin, or the like, is reacted with a polymer, wherein the polymer is crosslinked and converted to an insoluble form. In carrying out this method, it is necessary to introduce the hydroxyl, amino or carboxy group in advance into the polymer. Amino and carboxy groups can be easily introduced into the polymer by copolymerization. In the case of hydroxyl groups, they may be introduced by copolymerization of hydroxyethyl methacrylate, isopropenylphenol, firstly introducing vinyl acetate or glycidyl methacrylate or the like using a copolymerization process, followed by saponification of these by the action of a basic material to form hydroxyl groups. In the following process, the above-obtained polymer and a polyfunctional compound, such as epichlorohydrin, react with each other, said polymer being crosslinked and converted to an insoluble form, when the polymer is converted to an insoluble form in an aqueous solution, converted to an agar consistency . The polymer thus obtained is simply crushed and can be used immediately. If the aqueous solution dissolves in oil after dispersion, a granulated gel may be obtained.

According to the eighth method, the polymer complex is formed by copolymerizing the polymer with the above-mentioned active hydrogen-containing monomer or by combining the polymer with the copolymer of the monomer, in which case it is also possible to form the polymer complex by regenerating active hydrogen atoms in the polymer that are substituted with ammonium ions. when mixed with other polymer components by addition of an acid.

The above methods can be used either alone or in combination. In general, much more effective results are obtained when two or more of these methods are used.

With respect to the particular polymerization processes which can be used in the production of the water-binding agents applied in the process according to the invention, the following polymerization processes, which are given by way of example only, can be used with respect to the above methods:

1) polymerization of the monomer as it is in the solvent without diluting it to form a polymer block;

(2) polymerization in a solvent followed by drying of the polymer thus obtained or allowing the polymer to precipitate in a weak solvent to obtain the desired polymer;

3) obtaining the polymer in the form of a granulated polymer, using the suspension polymerization method,

4) obtaining the polymer in the form of a polymer latex using an emulsion polymerization method; and

5) combining the polymer with a water-insoluble fibrous material or a porous material using impregnating or grafting polymerization of the polymer solution to a water-insoluble fibrous material or a porous material.

With respect to the above specific polymerization methods, it can be stated that these polymerization processes can be initiated by simply heating the polymerization systems. However, better results are generally obtained when using polymerization initiators. There are no restrictions on the choice of polymerization initiators. Any polymerization initiator may be used in the polymerization process as long as it is capable of initiating radical polymerization. Examples are inorganic peroxides, organic peroxides, combinations of these peroxides and reducing agents, and azo compounds. Specifically, ammonium peroxodisulfate, potassium peroxodisulfate, hydrogen peroxide, tert-butyl peroxide, benzoyl peroxide, cumene hydroxy peroxide, tert-butyl peroxy-2-ethylhexanoate, butyl perbenzoate and the like can be used as the above polymerization initiators. As reducing agents which can be used in combination with the aforementioned polymerization initiators, sulfites, bisulfites, lower metal salts such as iron, copper and cobalt, organic amines such as aniline, sugars such as aldose and ketose, and other similar substances. As azo compounds in this context, azobisisobutylonitrile, 2,2'-azobis-2-amidinopropane hydrochloride, 2,2'-azobis-2,4-dimethylvaleronitrile, 4,4'-azobis-4-cyanovaleric acid and the like can be used. . It is also possible to use two or more of the above polymerization initiators in combination in carrying out the above polymerization processes. The amount of polymerization initiator used to be added to the polymerization may be in the range commonly used in similar cases, for example, in the range of 0.01 wt%. Preferably, the amount of initiator is from 0.05 to 2% by weight based on the monomer.

The polymer materials thus obtained, whether in the form of a block polymer or a polymer obtained after solvent evaporation, are crushed to a pulverulent material, i. the composition used in the water extraction process of the invention, or the polymer thus obtained can be melted and then formed into various shapes, such as flakes, fibers or film, which can be used as water absorbing and release means in this form. The polymer in the form of granules can be directly obtained already in the form of a granular composition for absorbing and releasing water without the need for further processing. On the other hand, when a latex polymer is obtained, the polymer may be impregnated or coated with a fibrous or porous material such as a fabric or paper, or a film may be prepared from the polymer to be used as an absorbent and releasing water.

According to the above procedures, the polymer or copolymer converted to an insoluble form (referred to herein as resin simplification) can be obtained in various forms. The particular form of the resin can be arbitrarily determined depending on the purpose for which the resin is to be used.

When the resin is used, for example, in suspended form or in dispersed form in a liquid, such as in a fluidized bed, it is possible to select the form of powder or beads.

The powdered product can be obtained by a variety of processes as described above, for example, by gel polymerization in aqueous solution, and then dried, and the resulting resin ground. On the other hand, the granular product can generally be prepared readily by applying a suspension polymerization method. Since the N-alkyl- or N-alkylene-substituted acrylamide or methacrylamide derivatives are generally highly water-soluble, suspension polymerization can be accomplished by a reverse phase suspension method wherein the monomer or an aqueous solution thereof is dispersed in an oil, it is further possible to apply a salting-out suspension polymerization process, in which the electrolyte is dissolved in a large amount of an aqueous solution to reduce the solubility of the monomer, or a precipitation and suspension polymerization method is used wherein the polymerization is carried out at elevated cloud point or higher. to precipitate the polymer. In addition, the polymer can also be combined with porous beads made of, for example, silica, alumina, or zeolite, for example by impregnating the porous beads with a polymer solution or grafting them onto the porous beads. guinea fowl. It is also possible to add another component which is miscible with the monomer or monomers but which is immiscible with the resulting polymer, by polymerization by any of the above polymerization methods. If this method of adding the third component is used, a porous resin can be made.

The water absorption and release agent prepared by any of the above methods used in the process of the present invention is in solid form and exhibits exceptionally good properties in that, when contacted with a solution or emulsion, it allows very absorbent water in a quick manner, while also allowing the water so absorbed to be retained in its volume. Upon heating, the composition contracts rapidly even in the presence of a large excess of water, thereby releasing the water already absorbed. It is also a very advantageous feature of the composition that the above-mentioned phases of water absorption and water retention and subsequent water release can be repeated as desired. The amount of water that can be absorbed by the water absorption and release agent varies depending on the composition of the resin from which it is made, the temperature at which the water extraction is performed, the composition of the particular aqueous solution from which such extraction of water is performed, and the like. In general, the composition is capable of absorbing water in an amount that is eight to hundred times the weight of the composition at ambient temperature (i.e., about 25 ° C). The amount of water that the composition is able to absorb increases as the temperature at which it is operated decreases.

Where a low molecular weight material, such as an inorganic salt, organic salt or water-soluble organic substance, is present in the dissolved solution in an dissolved state, the water absorbing and release means is capable of absorbing the aqueous component in such a way that this low molecular weight material. gets into this resin. It should be noted, as already mentioned in the prior art paragraph, that in conventional water separators, if the inorganic salt is present in an aqueous solution in the dissolved state, then the absorbency of the prior art resin is significantly drops. For example, when copolymers of acrylamide and sodium acrylates (sodium acrylate content of 21% by weight) are used that are crosslinked, for example, with methylene bisacrylamide, the amount of water absorbed in the polymer from 1N aqueous sodium chloride solution is so small that water which is absorbed by the same polymer from the distilled water environment. On the other hand, the percentage reduction in the amount of water in the water absorbing and release means applied in the process of the invention is much less and corresponds to about 10%. It can be concluded from the above that the amount of water that the composition is capable of absorbing is only little affected by the presence of salts dissolved in the aqueous medium. Conversely, it has been found that the water absorbing and release means applied in the process of the invention is capable of absorbing more water depending on the type of salt dissolved in the aqueous medium. An example of such a salt is calcium chloride.

in*

As mentioned above, the composition used in the process of the present invention may act in two ways depending on the molecular weight of the solute, in other words, a solution of the solute may be absorbed into the composition either with or without the solute present. That is, the composition used in the process of the invention functions as a molecular sieve. The critical molecular weight varies depending on the composition of the resin (i.e., the water absorbent and release agent) and the temperature of each individual resin. When the degree of insolubility of the resin is low and so a relatively large amount of water can be absorbed, for example, the degree of crosslinking is low or the resin is a copolymer of hydrophilic or ionic monomer, the critical molecular mass is critical. is generally large. On the other hand, if a given resin can absorb only a small amount of water, for example, because its degree of crosslinking is large or is a copolymer of a hydrophobic monomer, it is generally understood that the critical molecular mass. is small. When controlling the concentration of the aqueous solution of the present invention by means of a water absorbing and releasing agent, it should be noted that the substance dissolved in the aqueous solution must have a molecular weight. higher than the critical molecular mass. of the resin.

Regarding this critical molecular mass. it is very difficult to state any particular definitive value, since this value varies considerably depending on the composition and temperature of each resin used, i.e., the final value used. means for absorbing and releasing water, the composition of said individual aqueous solution, and the type of individual material to be concentrated. For example, the critical molecular weight of a resin obtained by cross-linking with (N-acryloylpyrrolidine) methylene bisacrylamide is in the region of about 1,000 at about room temperature when the resin is used to concentrate polyethylene glycol. On the other hand, the critical molecular mass. it is in the region of about 10,000 when this resin is used to concentrate dextran, protein or the like. In particular, the critical molecular mass. it is dependent on the state of the molecules which are dissolved in the aqueous solution, i.e. the extent of the size of the molecules. For this reason, it is impossible to give a specific value to this critical molecular mass. This critical molecular weight is related to a certain degree of distribution.

It should also be noted that particles or droplets not dissolved in water or suspended in water, such as droplets dispersed in emulsions, microorganisms, dirt in liquid waste from fermentation plants, etc., cannot be incorporated into the absorbent composition applied in the process of the invention. .

If the temperature of the composition is increased after the water has been absorbed by the composition, the composition is subject to shrinkage, thereby releasing the absorbed water. If this resin temperature is further increased, then a state occurs in which the shrinkage of the composition becomes extremely slow, in other words, a transition point occurs. This transition point is determined by the composition of each individual resin forming the composition. In general, this transition point can be controlled from 10 to 100 ° C. The shrinkage rate of each individual resin in the region of its transition point varies depending on the composition of the resin, the composition of the aqueous solution to which the resin is applied, etc. In general, however, the shrinkage rate varies from one to twenty times its own mass. As mentioned above, water can be absorbed and retained by the process of the present invention by heating and cooling the composition repeatedly. That is, it is generally possible to absorb water at a temperature in the range of from 0 to 100 ° C. Heating of the composition following the absorption of water and in which the composition is subject to shrinkage generally involves temperatures in the range of from 10 to 200 ° C, although this temperature may, of course, vary depending on the intended purpose of the resin.

The specific procedure for extracting water will be described below. The resin is first contacted with an aqueous solution from which water needs to be removed. Thereafter, the resin in which water is absorbed is separated from the aqueous medium and then exposed to a higher temperature atmosphere, releasing the water so absorbed. By repeating these sequential steps, a considerable amount of water can be separated by the resin according to the invention. When a low molecular weight material is dissolved in an aqueous solution, water can be separated in the form of an aqueous solution containing the low molecular weight material.

Where the aim of the process of the invention is to obtain a liquid remaining after this extraction, i.e. a valuable product remaining for this process after separation of the water by the water absorbing agent, the process is considered to be concentration or dewatering. On the other hand, if the aim of the process according to the invention is to obtain absorbed water by means of the aforementioned type, that is to say that the absorbed liquid is valuable in carrying out the process, then the above process is referred to as clean water recovery.

In particular, if the aim of the process of the present invention is to concentrate an aqueous solution, the concentration can be accomplished by bringing the resin into contact with the aqueous solution and repeating the above operation. In this way, a considerable proportion of the aqueous solution can be separated to achieve concentration. Where it is present in aqueous solution together with a low molecular weight substance. also macromolecules! then the macromolecular substance is only concentrated without concentrating the low molecular weight substance. in the remaining liquid, since the resin used in the process of the invention functions as a molecular sieve in this case.

When the aim of the process of the invention is to control the concentration of an aqueous solution by means of a water absorbing and releasing agent, the resin is contacted with the aqueous solution either as it is made or swollen with a suitable aqueous solution. . Thus, the concentration of the aqueous solution can be adjusted to the desired level by controlling the temperature of the aqueous solution. In this case, a dilution of the solution is achieved at a higher temperature, while a solution concentration is achieved at a lower temperature. Thereafter, the resin used may be separated by sedimentation, filtration, centrifugation or the like, or the supernatant may be separated to give a solution of the desired concentration. The aqueous solution can be adjusted to any desired value by simply varying the aqueous solution temperature as described above. The possibility of adjusting the concentration of the aqueous solution varies depending on the resin used, the ratio of resin to aqueous solution, and the temperature ranges used. In general, concentration adjustments ranging from about 0.01 to 100 times for a single starting aqueous solution can be achieved, but this cannot be applied exclusively to each individual situation. As already mentioned, only the concentration of macromolecules can be achieved according to the invention! In the case where the macromolecular substance is present in an aqueous solution together with a low molecular weight substance, this change in the concentration of the macromolecular substance does not affect the concentration of the low molecular weight substance present.

An important advantage of the process according to the invention is that the water-absorbent resin used in the process can easily be regenerated, for example by simply rinsing with water or heating the resin, which shrinks and releases the absorbed water. In this way, the resin can be reused. This is one of the most important features of the process of the present invention.

In carrying out the process of the invention, the resin-forming means for absorbing and releasing water can be applied in different ways and in different forms, depending on the particular purpose of use. In the basic embodiment of this application, the water absorbing and releasing means, which may be in the form of a powder, flakes, beads, fibers or film, is first contacted with the water present in the aqueous system and from which the water is to be removed. . Next, the water-absorbent composition is left in contact with the medium, absorbing water, and then separating the water-absorbent composition from the aqueous solution. A variety of methods can be used to bring the composition into contact with an aqueous medium to absorb water and then separate the composition from the aqueous solution, such as absorbing and releasing means. the water directly into the aqueous solution and then separating the absorbed water composition by sedimentation, filtration, centrifugation or the like, or the water absorbing and releasing agent is pre-positioned in a member that keeps the composition separate from the aqueous solution, e.g. be a bag or the like, wherein the composition placed in the bag is contacted with an aqueous solution to absorb water from the aqueous medium, and then the composition is separated from the aqueous medium after absorption, or it is also possible to and to treat the water-absorbent composition in the form of fibers, flat fabrics or the like, wherein the water-absorbent composition thus obtained is immersed in an aqueous solution to effect water absorption in the composition and thereafter withdrawn after absorption. from an aqueous solution. The above procedures can be performed many times. In the above-mentioned processes, it is preferred that the absorption of water by the water absorbing and releasing means is carried out at the lowest possible temperature, since the use of low temperatures results in the absorption of larger amounts of water.

In the process of the present invention, after the absorption has taken place, the water absorbing and releasing means is exposed to an atmosphere of elevated temperature to release the absorbed water. This can be done, for example, by immersing the composition in hot water or by blowing it with a hot gas such as steam, or allowing the composition to stand in a hot air environment such as an oven. If the object of the present invention is to use the water absorption and release agent repeatedly, it is economical to remove the water from the device as far as is practicable, as this will result in greater efficiency in the repeated absorption of water.

Specific examples of the use of the present invention with the water absorbent and release means include concentrating various aqueous solutions, particularly concentrating aqueous solutions containing edible substances, amino acids, proteins, polysaccharides, enzymes, and the like. concentrating aqueous systems that are difficult to concentrate due to heat denaturation sensitivity; and concentrating emulsions that cannot be easily concentrated because thermal denaturation (degradation) or degradation of substances present in these systems could also occur; temperatures and especially crystallization of substances which are sensitive to thermal decomposition (heat denaturation), further control of the concentration of aqueous solutions by changing the temperatures of these aqueous solutions while adjusting the absorption capacity of these resins and finally, the production of pure water from various aqueous solutions and sources, and in particular the production of pure water from aqueous systems containing microorganisms such as bacteria.

When using the process of the invention to absorb water in the composition specified above, it is very easy to achieve water retention in the composition. In particular, the water absorbing and retention means absorbs and retains water in its volume when only contacted with a liquid aqueous solution. At this point, it should be noted that there is no restriction on the shape of the water absorbing and release means. The water absorbent and release agent may be used in the form of a powder, flakes, fiber or film or as a mixture with another material, for example a fibrous material, depending on the applicability of the composition or the objective to be achieved. In this context, it should be noted that, as already mentioned, absorbed water can be released from the composition or, conversely, absorbed by the composition by simply changing the ambient temperature. This operation can be repeated as many times as necessary. From the foregoing, it is apparent that when using the process of the present invention, water can be absorbed and released by means of the water absorbing and releasing agent without the need for evaporation of the water by changing the ambient temperature, which is very energy intensive and indicated, damage to the substances in the system being treated may occur. For this reason, the process of the present invention using a water absorbing and releasing agent can be used for a variety of purposes from a wide range of applications.

Specific examples of application of the process of the invention include keeping the soil moist, modifying fibers such as acrylic fibers, removing water from a variety of solutions, modifying adhesives, preparing base materials for soft contact lenses, and preparing a resin base material suitable for use in the separation of proteins, enzymes and the like, a modification of polymeric flocculants, a destruction of concrete and the like, and a raw material from which water absorption and release means are made, used in the process according to the invention, to be used as raw materials for macromolecular absorbents which are suitable for sanitary purposes, for example for the production of sanitary napkins and wipes. for adsorbents of heavy metal ions, the process of the present invention can also be applied to compacting sludge and liquid waste materials; furthermore, the resin from which the water-absorbing and release agent used in the process of the present invention is made can be used as a base material for gels for water-based materials, as a means of preventing the condensation of materials from which walls, ceilings, etc. are made; as raw materials for materials used as waterproofing insulators; and as raw materials for fire retardants and / or noise insulating materials; .

When a low molecular weight substance is present in the aqueous solution to be treated according to the present invention, the water absorbing and release means also has the ability to also absorb the low molecular weight substance. in the form dissolved in said solution. A further feature of the process of the present invention to be emphasized is that, although it already absorbs water in its volume, it is still capable of rapidly diffusing a low molecular weight substance from a solution in which it is dissolved. to a volume such that the concentration of the substance in solution is equivalent to the concentration of the substance in the composition. A specific example of the use of these properties is, for example, the application of a water absorbent and release agent to remove low molecular weight species. aqueous solutions or emulsions containing macromolecular substances, such as proteins, together with these low molecular weight substances dissolved in the medium. This kind of separation has hitherto been performed using permeable membranes or the like. For example, the process of the present invention is applicable to the purification of these macromolecular substances, and it has hitherto been thought to be difficult to remove salts or the like from the macromolecular solution. In addition, it is also contemplated that the water absorbing and releasing means used in the process of the present invention will find use as a containment agent for a sustained release environment due to their ability to allow diffusion of low molecular weight species.

As mentioned above, the water absorbing and releasing means can be readily regenerated, utilizing their ability to swell and contract, and these characteristics can be utilized while varying temperatures. Since the water absorption and release agent used in the process according to the invention exhibits the above-mentioned excellent properties, which are present even in the presence of inorganic salts, its absorption capacity does not diminish too much and also retains its good ability to maintain water absorption. the shape, it can be stated that the following new advantageous effects can be achieved by its use. The first of these advantageous novel effects is that water absorption is not carried out by simultaneous transfer of water to another phase, such as evaporation, lyophilization or the like. As a result, this means allows water separation at low temperature and low energy consumption. Water absorption using one or more water absorbing and releasing means does not necessarily require the use of large devices so that water absorbing devices can be installed at any point of use. Secondly, the water absorbing and release means can be used to control the concentration of aqueous solutions by simply varying their temperatures without the need to transfer the water to another phase. In this way, it is possible to eliminate the loss of solute which occurs due to its decomposition or damage that may occur due to temperature or phase changes. Thirdly, these water absorbing and releasing means can absorb and thereby separate larger amounts of water as temperature drops. For this reason, these compositions are significantly effective in concentrating or crystallizing aqueous solutions containing substances susceptible to thermal decomposition or damage (thermal denaturation). Fourthly, the water absorbing and release means used in the process of the invention exhibit molecular sieve properties. Accordingly, the compositions can be used to selectively adjust the concentrations of macromolecular substances such as proteins, enzymes, and the like, without altering the concentration of low molecular weight substances present, such as buffering agents and the like. . Fifth, the amount of water retained by the water absorption and release means can be controlled by changing the water temperature. Because of this property, the water content of the ambient atmosphere can only be controlled by adjusting its temperature. Sixthly, because of the nature of the resin, the absorbed water can also be released in an aqueous environment by heating the resin. In addition, due to the properties of the resin, water can diffuse through the resin very rapidly. Finally, the resins used in the process of the invention have the advantage that they can be easily washed and easily recovered for reuse.

The process of the invention together with a detailed specification of the water absorbing and releasing means used in carrying out the process of the invention will be described in more detail below by means of the following examples. These examples are given for illustrative purposes only and are not intended to limit the scope of the invention in any way.

Example 1

In this example, N-acryloylpyrrolidine, which contained 1 wt. tert-butylperoxy-2-ethylhexanoate, allowed to stand at 40 ° C for 50 hours to effect a solvent-free polymerization to obtain block polymer. The polymer was then crushed and the powder was sieved, sampled in a 20 to 100 mesh size range according to ASTM E-11-61 as a sample. 1 g of sample was poured into distilled water at a preselected temperature and allowed to stand to swell, then removed by filtering the distilled water with a wire mesh to determine the swelling rate. The results of the measurements are given in Table 1 below.

Table 1

Temperature (° C) 9 25 33 40 Swelling rate (g) 30.7 24.8 18.6 15.1 Temperature (° C) 49 58 70 77 Swelling rate (g) 11.4 5.5 3.6 2.7

Example 2

A total of 1.0 grams of the powder sample obtained in Example 1 was added to a 50 milliliters graduated cylinder. At first, the sample was allowed to swell at room temperature and the swelling volume of the sample was determined. subtraction on the scale. The sample was then allowed to stand for 15 minutes successively at all temperatures shown in Table 2 below, in the same order as shown in this table. After each individual temperature was reached, the swelling volume was measured. The results obtained are shown in Table 2 below.

Table 2

Measurement sequence Temperature (° C) Swelling volume (ml) 1 32 26.7 2 25 31.6 3 10 36.4 4 25 31.8 5 32 26.7 6 50 15.8 Measuring order 7 8 9 10 11 Temperature (° C) 58 68 58 50 32 The volume of swelling (ml) 8.9 6.0 8.9 15.4 26.7

Examples 3 to 38

In these examples, samples of powders obtained by copolymerization of the corresponding monomers shown in Table 3 were used, and the copolymers thus obtained were ground in the same manner as in Example 1. The same procedure was followed as in Example 2 to determine swelling volumes of 1.0 gram samples at 25 and 50 ° C in each case. The results obtained are summarized in Table 3 below.

Table 3

Example Copolymer blend (w / w) 25 ° C volume (ml) 50 ’C 3 N-n-propyl acrylamide (99.9) / Ν, N'-methylenebisacrylamide (0,1) 15.0 5.5 4 n-acryloylpyrrolidine (85) / methyl methacrylate (15) 11.5 4,5 5 N-acryloylpyrrolidine (99) / ethylene glycol (ref. 600) dimethacrylate (1) 9.0 2.5 6 N, N-dimethacrylamide (99.9) Ν, N'-methylenebisacrylamide (0,1) 22.0 19.5 7 N-acryloylpyrrolidine (90) / N-ethyl acrylamide (10) 24.0 6.5 8 N-acryloylpyrrolidine (90) / acrylonitrile (10) 11.5 5.5 9 N-acryloylpyrrolidine (99) / Ν, Ν-diallylacrylamide (1) 12.0 5.0 10 N-acryloylpyrrolidine (99) / hydroxyethyl methacrylate (1) 19.0 6.0 11 N-acryloylpyrrolidine (90) / vinyl acetate (10) 15.0 6.5 12 N-Ethyl acrylamide (99.9) / Ν, N'-methylenebisacrylamide (0,1) 22.0 15.0 13 N-acryloylpyrrolidine (99) N-methylolacrylamide (1) 9.0 5.0 14 N-acryloylpyrrolidine (90) / APPS-Na ¹ ) (10) 90.0 50.0 (measured at 90 ° C

Table 3 (continuation) Example Copolymer blend (w / w) Swollen volume (ml) 25 ^e C Deň: 32 ° C 15 Dec N-acryloylpyrrolidine (99.9) / Ν, N'-methylenebisacrylamide (0,1) 23.0 8.0 16 N-acryloylpyrrolidine (99.9) / AMPS ² ) (0.1) 30.0 13.0 17 N-acryloylpyrrolidine (90) / N-acryloylpiperidine (10) 26.0 5.0 18 N-acryloylpyrrolidine (95) / methyl methacrylate (5) 24.0 6.0 19 Dec N-acryloylpyrrolidine (90) / Ν, N-Dimethylacrylamide (10) 34.0 18.5 20 May N-acryloylpyrrolidine (99) / vinyl acetate (1) 31.0 8.0 21 N-acryloylpyrrolidine (99) / N-methacryloylpiperidine (1) 32.0 7.0 22nd N-acryloylpyrrolidine (99) / triethylene glycol diacrylate (1) 8.0 4.0 23 N-acryloylpyrrolidine (99) / acrylic acid (1) 24.0 7.5 24 N-acryloylpyrrolidine (99) / methacrylic acid (1) 12.0 7.0 25 N-acryloylpyrrolidine (99) / polyethylene glycol (ref. 400) dimethacrylate (1) 8.0 5.0 26 N-acryloylpyrrolidine (90) / hydroxyethyl acrylate (10) 16.0 6.0 27 Mar: N-acryloylpyrrolidone (99) / triethylene glycol dimethacrylate (1) 8.0 4.0 28 N-acryloylpyrrolidine (99) / styrene (1) 18.5 6.0 29 N-acryloylpyrrolidine (95) / polyethylene glycol (ref. 600) diacrylate (5) 10.0 4,5

Table 3 (continuation) Example Copolymer blend (w / w) 25 ° C volume (ml) 50 ° C 30 N-acryloylpyrrolidine (90) / DMAPMA ( ³ ) (10) 12.0 9.5 31 N-acryloylpyrrolidine (99) / acrylamide (1) 28.0 12.0 32 N-acryloylpyrrolidine (90) / N-n-butyl acrylamide (10) 16.0 5.5 33 N-acryloylpyrrolidine (99) / Ν, Ν'-diacryloylimide (1) 8.0 4,5 34 N-acryloylpyrrolidine (99) / polyethylene glycol (ref. 400) diacrylate (1) 8.0 5.0 35 N-acryloylpyrrolidine (99) / N-n-hexylacrylamide (1) 23.0 6.0 36 N-acryloylpyrrolidine (90) / N-methacryloylpyrrolidine (10) 34.0 11.5 37 N-acryloylpyrrolidine (90) / N-vinyl-2-pyrrolidone (10) 11.5 6.5 38 N-acryloylpyrrolidine (99) / ethyl acrylate (1) 20.0 6.5

Note: 1) APPS-Na: Sodium 2-acrylamido-2-phenylpropanesulfonate

2) AMPS: 2-acrylamido-2-methylpropanesulfonic acid

3) DMPMA: Ν, Ν-dimethylaminopropylmethacrylamide.

Example 39

In this example, a 30% aqueous solution of N-acryloylpyrrolidine was first placed in a Dewar flask. After purging the solution with nitrogen gas, sodium bisulfite and potassium persulfate were added to the vessel at a temperature of 30 [deg.] C., each amounting to 0.5% by weight. with respect to the amount of said N-acryloylpyrrolidine. Then, the N-acryloylpyrrolidine was allowed to polymerize under adiabatic conditions. The resulting gel was then chopped and dried at 120 ° C. The material was then pulverized to separate from the total fraction having a particle size of 20 to 100 in accordance with ASTM E-11-61. Thereafter, the same procedure was carried out as in Example 2, in which the swelling volumes of a 1.0 gram powder sample at 25 and 50 ° C were determined. These volumes were found to be 22.0 ml and 7.5 ml.

Example 40

First, a 20% aqueous solution of N-isopropyl acrylamide containing 10,000 ppm of N, N'-methylenebisacrylamide was adiabatically polymerized in the same manner as in Example 39. The product was then treated in the same manner as in Example 39, whereby a powder sample was obtained as the final product. Thereafter, the same procedure as in Example 2 was followed, recording swelling volumes of a 1.0 gram powder sample at temperatures of 25 and 50 ° C. These volumes were found to correspond to 19.0 milliliters and 11.0 milliliters. Examples 41 to 44

According to these examples, a 1.0 gram sample of the powder obtained by the procedure of Example 1 was added to each of the aqueous electrolytic solutions listed in Table 4. Thereafter, swelling volumes were measured in the same manner as in Example 2. of this sample at 30 ° C. The results obtained are shown in Table 4 below.

Table 4

Example Electrolyte Concentration (g per 100 g water) Volume swelling (ml) 41 sodium chloride 5.8 24.4 42 calcium chloride 1/1 30.6 43 ammonium sulfate 1.3 21.9 44 seawater 25.5

Example 45

One gram of the sample obtained in the same manner as in Example 1 was added to 100 ml of a 3.5% aqueous solution of sodium chloride at 30 ° C. The resulting mixture was allowed to stand for 1 hour. After this period, the concentration of sodium chloride in the aqueous solution was measured and found to be 3.5%. At the same time, the swelling volume of this solution was also measured, measuring 25.3 ml. The solution was cooled to 10 ° C and allowed to stand for 15 minutes. The sodium chloride concentration in this aqueous solution was found to be 3.5%. At the same time, a swelling volume of 33.4 ml was found at this temperature. The sample was then reheated to 50 ° C, where it was allowed to stand for 15 minutes. Again, the concentration of sodium chloride in the aqueous solution was determined to be 3.5%. The swelling volume at this temperature was 19.5 ml. Example 46.

A portion of the powder sample obtained in the same manner as in Example 1 was swelled in distilled water and the resulting 20 g gel was collected. The sample was taken up in 30 ml of 5% aqueous sodium chloride solution and stirred. After three minutes, the sodium chloride concentration in the aqueous solution was determined by refractive index. This concentration was found to be 3.1%. After separating the swollen sample by filtration, the sample was heated to 60 ° C to release the absorbed water. The concentration of sodium chloride contained in the aqueous solution absorbed in the gel was again measured and found to be 3.1%.

Example 47

The procedure was carried out by placing 0.5 grams of the powder sample obtained as in Example 1 at 15 ° C in 30 grams of normal milk. After mixing the mixture, the powder sample was filtered off. The weight of the filtrate was 21 grams. This implies that 9 grams of water was absorbed from the milk.

Example 48

In this example, a portion of the powder sample obtained in Example 1 was swelled in distilled water, and the resulting mixture was then filtered using a glass filter. Thereafter, the water-containing composition on the filter was compressed by means of a glass plate, and it was found that no water was released. In this way, the water retention of the composition was confirmed.

Example 49

0.2 g of the powder sample obtained in Example 1 was added to 35 ml of benzene containing 800 ppm of water, and the resulting mixture was mixed well The water content of the benzene was determined. The water content was found to have dropped to 400 ppm.

Example 50

In this example, a test was performed for dewatering the material under pressure using leached sludge, which was pre-flocculated with cationic flocculants. Specifically, a flat filter paper was loaded into a 9-centimeter cylinder, a portion of the powder sample obtained as described in Example 1, a further flat filter paper, a fraction of leached sludge flocculated as described above, flat filter paper, then another portion of the powder sample obtained in Example 1, and yet another flat filter paper, the layers being stacked in the above order. The column was then compressed from top to bottom with a pressure of 3 kg / cm ² and compression was carried out for 5 minutes. After this compression for a preselected interval, the filter papers were peeled off and the water content of the sludge was further determined. This content was equivalent to 55%.

A further test for dewatering the material under pressure was then carried out in the same manner as above, except that the same portion of the same sludge was coated with layers of filter paper only. The water content of the treated sludge was found to be 61%.

Example 51

0.5 g of the powder sample obtained in Example 1 was added to 50 g of 43% SBR latex at room temperature at room temperature. The resulting mixture was mixed well. The mixture was then filtered. The concentration of this SBR latex in the filtrate was found to be 49%. Example 52

5 grams of N-acryloylpyrrolidine was placed in a 5 ml sample tube, followed by the addition of 0.02 grams of 5-butylperoxy-2-ethylhexanoate. Block polymerization was then carried out at 40 ° C to obtain block polymer. The polymer was then crushed and a fraction having a particle size in the 20 to 100 mesh size range according to ASTM E-II-61 was collected as a sample. Then 0.5 grams of this powdered sample was loaded at room temperature into 50 grams of 43% SBR latex. After proper mixing of the resulting mixture, the concentration of this liquid latex was measured. This concentration was found to be 49%. The liquid latex was then cooled to 10 ° C, followed by thorough mixing. The latex concentration was then measured again. It was found to be 58%. Liquid latex was then reheated to 40 ^e C where it was thoroughly mixed. By measuring the concentration of this latex, it was found to be 45%. The liquid latex was then thoroughly mixed again at room temperature. The concentration of this latex was now 48%. In addition to these measurements, a powder sample was observed microscopically both before and after each measurement. In these observations, it was found that the powder sample was not crushed or otherwise physically damaged by temperature changes or agitation.

Example 53

An aqueous solution of N-acryloylpyrrolidine containing 0.5 wt. Ν, Ν'-methylenebisacrylamide, which solution was prepared by dissolution

507.5 grams of N-acryloylpyrrolidine and 2.6 grams of N, N'-methylenebisacrylamide in 1170 grams of water. After cooling the aqueous solution to 10 ° C, the solution was poured into a 2 liter stainless steel Dewar flask. Nitrogen was bubbled through the solution at 1 liter / minute for 1 hour using a ball filter. An aqueous solution of 2.55 grams of ammonium persulfate dissolved in 10 grams of water and another aqueous solution of 1.16 grams of sodium bisulfite dissolved in 10 grams of water were added simultaneously to the aqueous nitrogen-bubbled solution. then the adiabatic polymerization of these reactants took place. The polymer gel thus obtained was then chopped, dried and crushed. In this case, a grain fraction having a particle size in the range of 20 to 100 according to ASTM E-11-61 was separated as a sample. 0.5 g of this powder sample was placed in 20 ml of an aqueous 0.5% bovine albumin serum solution. The resulting mixture was stirred at a preselected temperature for 1 hour. The mixture was then allowed to stand for 5 minutes. To determine the concentration of this mixture, the absorbance of the supernatant was measured at 254 nm. Agitation of the sample powder and aqueous solution of bovine albumin serum was performed at 30, 15 and 5 ° C. The concentration in the supernatant corresponding to these three temperatures was 0.71% (at 30 ° C), 0.78% (at 15 ° C) and 0.83% (at 5 ° C). In addition to these measurements, the powder sample was also observed microscopically both before and after each measurement. In these observations, it was found that the powder sample was not comminuted or otherwise damaged by temperature changes and agitation.

Example 54

According to this example, to 10 grams of the solution obtained by dissolving bovine albumin serum in 0.9% aqueous sodium chloride solution such that the concentration of bovine albumin serum was adjusted to 1%, 10 grams of gel (containing water 9, 5 grams) was obtained by allowing a portion of the powder sample of Example 53 to swell in distilled water. After stirring the resulting mixture at room temperature for 15 minutes, the absorbance of the resulting supernatant was measured at 254 nm to determine the concentration of bovine albumin serum in the aqueous solution. The concentration of bovine albumin serum was 0.75 percent by weight. In addition to these measurements, the electrical conductivity of the solution was measured to determine a sodium chloride concentration of 0.47%. Thereafter, the solution was heated to 30 ° C where it was found that the concentration of bovine albumin serum decreased to 0.71%. Upon cooling to 15 ° C, the concentration increased to 0.78%. By further cooling the solution to 5 ° C, the bovine albumin serum concentration increased further to 0.83%. The solution was again warmed to room temperature. With this heating, the concentration of bovine albumin serum decreased to 0.75%. During the above measurements, the concentration of sodium chloride was determined and found to be still 0.47%.

Examples 55 to 62

The procedure was carried out by adding 0.5 grams of a sample in the form of 20 grams of a 0.5% aqueous solution of polyethylene glycol having in each case a molecular weight as shown in Table 5 below. of powder obtained in the same manner as in Example 53. After the mixture was stirred at a preselected temperature for 30 minutes, the refractive index of the resulting supernatant was measured to determine the polyethylene concentration in the supernatant. The results are set forth in Table 277398 B6 below.

Table 5

Example Molecular mass polyethylene glycol Liquid concentration above the sediment Deň: 22 ° C (%) 25 ’C 10 ’C. Deň: 32 ° C Low: 14 ° C 55 200 0.55 0.51 0.53 - - 56 600 0.52 0.54 0.52 - - 57 1 000 0.53 0.55 0.57 - - 58 2 000 0.59 0.57 0.61 0.59 0.60 59 4 000 0.62 0.56 0.64 0.61 0.65 60 6 000 0.75 0.62 0.84 0.74 0.86 61 11 000 0.76 0.62 0.87 0.77 0.86 62 20 May 000 0.82 0.64 0.87 0.82 0.89

Examples 63 to 67

0.5 g of the powder sample obtained as described in Example 53 and 20 ml of a 0.5% aqueous solution of dextran of various molecular weights, which are given in each case in the following, were used. The concentration in the supernatant was measured in the same manner as in Example 55. The results are shown in Table 6.

Table 6

Example Molecular: dextran wt. Concentration in liquid above Deň: 32 ° C sediment (%) Deň: 22 ° C 10 ^e C 63 180 (fruktoza) 0.57 0.56 0.56 64 9 000 0.52 0.59 0.63 65 40 000 0.54 0.69 0.79 66 460 000 0.51 0.71 0.80 67 2 000 000 0.54 0.71 0.80

Examples 68 to 71

In these examples, 10 grams of gel (containing 9.5 grams of water) were obtained by allowing the sample of powder of Example 53 to swell in distilled water, followed by 10 grams of a 1% aqueous dextran solution of molecular weight which is shown for each experiment in Table 7 below, and the dextran concentration in the supernatant was measured in the same manner as in Example 55. The results are shown in Table 7.

Table 7

Example Molecular mass. Liquid concentration above the sediment

dextran 25 ’C Deň: 32 ° C Low: 14 ° C Deň: 22 ° C 10 Ί 68 9 000 0.59 0.52 0.63 0.52 0.64 69 40 000 0.69 0.54 0.79 0.68 0.79 70 460 000 0.71 0.51 0.80 0.71 0.80 71 2 000 000 0.71 0.54 0.80 0.70 0.82

Examples 72 to 76

0.05 g of the powder sample obtained according to Example 53 was used, followed by 2 ml of a 0.5% aqueous solution of different molecular weight proteins shown in the following table in each experiment. In these examples, the protein concentration in the corresponding supernatant was measured in the same manner as in Example 53. The results obtained are shown in Table 8.

Table 8

Example Protein Molecular Concentration of the Liquid Above the Pellet Mass.

Name Deň: 29 ° C Noc: 18 ° C Low: 14 ° C 72 lysozyme 14 300 0.51 0.69 0.83 73 β-lacto- globulin 18 400 0.62 0.66 0.76 74 trypsinogen 24 000 0.53 0.56 0.62 75 pepsin 34 700 0.52 0.61 0.77 76 white albumin from eggs 45 000 0.67 0.70 0.76

Example 77

A 30% aqueous solution of N-n-propyl acrylamide containing 0.5 wt. N, N'-methylenebisacrylamide using the same procedure of Example 53. 0.6 g of powder and 20 ml of 0.5% bovine aqueous solution were used. albumin serum, in which the concentration of bovine albumin serum in aqueous solution was determined at different temperatures, and the procedure was the same as in Example 53. In this way, the individual concentrations were found to be: 0.63% (at 30 ° C); 70% (at 15 ° C) and 0.84% (at 5 ° C).

Example 78

10 grams of gel (9.4 grams water content) were obtained by allowing a portion of the powder sample of Example 77 to swell in distilled water to determine the concentration of bovine albumin serum at various temperatures. This was carried out in the same manner as in Example 54. The concentration at room temperature was 0.65%. When heated to 30 ° C, this concentration dropped to 0.63%. Upon cooling to 15 ° C, the concentration increased to 0.70%. After the solution was cooled further to 5 ° C, the concentration increased to 0.84%. However, when the solution was brought back to room temperature, the concentration of course changed to 0.69%. During these measurements, the sodium chloride concentration remained constant at 0.46%.

Examples 79 to 83

0.6 g of the powder sample obtained according to Example 77 and 20 g of a 0.5% aqueous polyethylene glycol solution having a molecular weight as shown in Table 9 below were used. In these experiments, the concentration of polyethylene glycol in the corresponding supernatant was determined in the same manner as in Example 55. The results obtained are shown in Table 9.

Table 9

Example Molecular mass. Concentration in liquid over polyethylene glycol deposit (%)

Deň: 22 ° C Deň: 32 ° C 10 ’C. Deň: 32 ° C 25 Ί 79 1 000 0.54 0.51 0.52 - - 80 2 000 0.56 0.56 0.56 - - 81 4 000 0.59 0.55 0.59 0.54 0.58 82 6 000 0.65 0.59 0.74 0.59 0.64 83 11 000 0.64 0.54 0.71 0.52 0.65

Examples 84 to 88

0.6 g of the powder sample obtained in Example 77 and 20 ml of a 0.5% aqueous solution of various dextrans, the molecular weight of which was used in the examples, were used. The concentration of dextrans in the supernatant was determined in the same manner as in Example 55. The results are shown in Table 10.

Table 10

Example Molecular mass.

dextran

Concentration in the supernatant (%)

Deň: 32 ° C 25 ’C 10 ° 84 180 (fructose) 0.51 0.54 0.52 85 9 000 0.54 0.62 0.62 86 40 000 0.52 0.63 0.63 87 460 000 0.53 0.66 0.80 88 2 000 000 0.54 0.67 0.76

Examples 89 to 92

10 grams of gel (9.4 grams of water) were obtained by leaving a portion of the powder sample of Example 77 in distilled water, and 10 grams of a 1% aqueous solution of various The dextrans, whose molecular weight is shown in Table 11 for each individual case, were measured for the dextran concentration in the corresponding supernatant in the same manner as in Example 55. The results are shown in Table 11. .

Table 11

Example Molecular mass dextran Concentration in the supernatant (%) Deň: 22 ° C Deň: 32 ° C Low: 14 ° C Deň: 22 ° C 10 ’C. 89 9 000 0.62 0.54 0.62 0.61 0.64 90 40 000 0.63 0.52 0.63 0.60 0.63 91 460 000 0.66 0.53 0.80 0.65 0.80 92 2 000 000 0.67 0.54 0.76 0.67 0.77 Examples 93 to 97 At implementation of procedures under these examples were used 0.06 grams of sample in the mold powder, which was obtained according to example-

du 77, and 2 milliliters of a 0.5% aqueous solution of various proteins, the molecular weight of which is shown in Table 12 in each case. In these experiments, the protein concentration in the corresponding supernatant was determined in the same manner as in Example 53. The results obtained are shown in Table 12.

Table 12

Example Protein Name Molecular mass Concentration in the supernatant (%) Deň: 29 ° C Noc: 18 ° C Low: 14 ° C 93 lysozyme 14 300 0.53 0.56 0.61 94 f ! -lactoglobulin 18 400 0.52 0.67 0.85 95 trypsinogen 24 000 0.53 0.62 0.80 96 pepsin 34 700 0.55 0.64 0.80 97 white albumin from eggs 45 000 0.54 0.68 0.82

Examples 98 to 102

In the embodiment of these examples, the aqueous solution of N-acryloylpyrrolidine, which contained 4.7 wt. Sodium 2-acrylamido-2-phenylpropanesulfonate, subjected to salting-out suspension polymerization using Glauber's salt or the like, the bead gel thus obtained was dried to obtain the desired sample. This beaded sample was allowed to swell in distilled water to form a gel. 10 grams of the gel thus prepared (water content 9.75 grams) and 10 grams of a 1% aqueous solution of various polyethylene glycols, the molecular weight of which is shown in Table 13 below, were determined. in the corresponding supernatant as described in Example 55. The results are shown in Table 13 below.

Table 13

Example Molecular mass. Concentration in liquid over polyethylene glycol deposit (%)

Deň: 22 ° C Deň: 32 ° C Low: 14 ° C Deň: 22 ° C Low: 14 ° C 98 2 000 0.62 0.61 0.64 0,62, 0.65 99 4 000 0.65 0.65 0.69 0.66 0.70 100 ALIGN! 6 000 0.74 0.70 0.84 0.74 0.83 101 11 000 0.79 0.68 0.87 0.79 0.87 102 20 May 000 0.84 0.67 0.95 0.84 0.96

Examples 103 to 106

In the embodiment, 0.25 grams of the sample of beads obtained according to Example 98 and 20 grams of a 0.5% aqueous solution of each of the various dextrans, the molecular weight of which is given in Table 14 below, were used. In these examples, the concentration in the corresponding supernatant was measured in the same manner as in Example 55. The results obtained are shown in Table 14 below.

Table 14

Example Molecular mass. Concentration in liquid above dextran deposit (%)

Deň: 22 ° C Deň: 32 ° C Low: 14 ° C Deň: 32 ° C 25 ° ' 103 9 000 0.60 0.59 0.62 0.57 0.60 104 40 000 0.80 0.63 0.90 0.63 0.80 105 460 000 0.98 0.66 1.18 0.65 0.97 106 2 000 000 1,02 0.68 1,23 0.69 1,02

Example 107

0.5 g of the sample in the form of beads obtained by the procedure of Example 98 was introduced at 15 DEG C. into 30 grams of normal milk. After mixing the resulting mixture, the mixture was filtered. The weight of the filtrate was 18 grams. This means that 12 grams of water has been removed.

Example 108

To 50 grams of SBR latex having a concentration of 43% was added 0.5 grams of a bead sample obtained as in Example 98 at ambient temperature. The resulting mixture was then stirred at the same temperature. After proper mixing, it was finally filtered. The concentration of SBR latex in the filtrate was 52%.

Examples 109 to 113

In the procedures of the Examples, 0.25 grams of beads were obtained in the same manner as in Example 98, followed by 20 ml of a 0.5% aqueous solution of various polyethylene glycols, the molecular weight of which is shown in the following examples. The concentrations of polyethylene glycol in the corresponding supernatant liquids were determined in the same manner as in Example 55. The results are shown in Table 15.

Table 15

Example Molecular mass. Concentration in liquid over polyethylene glycols deposit (%)

Deň: 32 ° C Deň: 22 ° C Low: 14 ° C 109 2 000 0.61 0.62 0.64 110 4 000 0.65 0.65 0.69 111 6 000 0.70 0.74 0.84 112 11 000 0.68 0.79 0.87 113 20 000 0.67 0.84 0.95

Examples 114-117

0.25 g of a sample of beads obtained as in Example 98 was used, followed by 20 ml of a 0.5% aqueous solution of the individual dextrans having a molecular weight. The concentration of the supernatant was determined in the same manner as in Example 55. The results obtained are shown in Table 16.

Table 16.

Example Molecular mass. Concentration in liquid over dextrans sediment (%)

Deň: 32 ° C Deň: 22 ° C Low: 14 ° C 114 9 000 0.59 0.60 0.62 115 40 000 0.63 0.80 0.90 116 460 000 0.66 0.98 1.18 117 2 000 000 0.68 1,02 1,23

Example 118

According to this example, a benzene solution containing 5 wt. N-acryloylpyrrolidine, azobisisobutylnitrile added in an amount corresponding to 1% by weight, based on the amount of N-acryloylpyrrolidine. The reactants were allowed to polymerize at 60 ° C for 5 hours under a nitrogen atmosphere. After polymerization, 5 sheets of polypropylene nonwoven were stacked and then dipped into the benzene solution to impregnate the sheets with benzene solution. Then, the nonwoven was removed from the benzene solution and then allowed to stand at 150 ° C in a drying apparatus for 10 hours. After drying, the nonwoven fabric was readily cleaved to a pulp-like form. 1.0 g of the pulp sample was then suspended in distilled water, and the resulting suspension was filtered. It was found that wt. of the sample corresponds to 3.1 grams. From the above it is clear that the sample absorbed water at 2.1 grams.

Example 119

A 30% aqueous solution of N-acryloylmorpholine containing 5,000 ppm of N, N'-methylenebisacrylamide was charged to a Dewar flask, and then purged with nitrogen gas. Then 2,2'-azobis (2-amidinopropane) hydrochloride was added at 20 ° C in an amount corresponding to 1.3% based on the amount of N-acryloylmorpholine. The above reactants were subjected to adiabatic polymerization. The resulting gel was then chopped and dried at 120 ° C. The gel was then comminuted and a fraction having a particle size in the 20 to 100 mesh size range according to ASTM E-II-61 was sampled. Thereafter, the same procedure was carried out as in Example 2, in which the swelling volumes of a 1.0 gram sample were determined at 25 ° C and 50 ° C. These volumes were found to correspond to 14.5 ml and 11.5 ml.

Example 120

A powder sample was obtained in the same manner as in Example 119, with the polymerization and milling carried out in the same manner except that N-ethylmethacrylamide and polymer were used instead of N-acryloylmorpholine. The initiator was added at 50 ° C. Swelling volumes of 1.0 grams of powder samples at 25 ° C and 50 ° C were then determined in the same manner as in Example 2. The swelling volumes were found to match

18.5 milliliters and 13.5 milliliters.

Example 121

A powder sample was obtained by polymerizing and milling in the same manner as in Example 119 except that a 50% aqueous solution of Nn-propyl methacryl (50%) was used as the monomer solution. and N, N-dimethylacrylamide (50 percent) containing 10,000 ppm of N, N'-methylenebisacrylamide, and potassium sulfate and sodium bisulfite were used as polymerization initiators in amounts of 1.5 percent and 0.69 percent, based on the monomers, said polymerization initiators were added at 30 ° C. The swelling volumes of the 1.0 gram powder sample at 25 ° C and 50 ° C were then determined in the same manner as in Example 2. These volumes were found to correspond to 28.0 ml and 21.0 ml, respectively.

Comparative Example 1

In this embodiment, a 30% solution of N-n-butyl acrylamide, which contained 5,000 ppm of Ν, Ν'-methylenebisacrylamide, in N, N-dimethylformamide (hereinafter referred to as DMF) was placed in a Dewar flask. After purging the solution with nitrogen gas, azobisisobutylonitrile was added at 30 ° C and 1.5%. The above reactants were then allowed to polymerize during adiabatic polymerization. The gel was then chopped and dried at 120 ° C. The sample was then milled and the fraction having a particle size in the 20 to 100 sieve range according to ASTM E-11-61 was screened. The swelling weight of the 1.0 grams powder sample at 25 ° C and 50 ° C was then determined in the same manner as in Example 1. The weight was found to be 2.2 grams and 2.0 grams. .

Comparative Example 2

According to this embodiment, the powder sample was obtained by polymerizing and comminuting in the same manner as in Comparative Example 1, except that Ν, Ν-diethyl acrylamide was used instead of N-n-butyl acrylamide. The weight of 1.0 grams of samples swelled in the same manner at 25 and 50 ° C as in Example 1 was then measured. equivalent to 4.8 grams and 2.5 grams.

Comparative example

The powder sample was obtained by polymerizing and milling in the same manner as in Comparative Example 1 except that N-acryloylpiperidine was used instead of N-n-butyl acrylamide. The weights of the swollen 1.0 gram samples were then measured at 25 and 50 ° C in the same manner as in Example 1. The weights were found to be 3.3 grams and 2.3 grams.

Claims (2)

CLAIMS 1. A method for extracting water from aqueous macromolecular solutions or emulsions, comprising contacting the aqueous solution or emulsion with a water absorbing and releasing agent, said composition comprising a water-insoluble resin representing a polymer of at least one monomer selected from: a group of N-alkyl-substituted or N-alkylene-substituted acrylamides or methacrylamides represented by the following general formula I: ch ₂ (I) Ί 9 wherein R and R are each hydrogen or methyl, and R ³ is methyl, ethyl or propyl, with the proviso that R is ethyl or propyl when R ² is hydrogen and R ³ is methyl or ethyl when R ² is methyl, or R ² and R ³ together form a group -4 2 1 ^CH or CH ₂ or a copolymer of at least one monomer selected from the group mentioned acrylamide or methacrylamide and one or more other copolymerizable monomers selected ze.skupiny hydrophilic monomers comprising hydroxyethyl methacrylate, hydroxyethyl acrylate, acrylamide and N-vinyl-2-pyrrolidone, from ionic monomer groups including sodium 2-acrylamido-2-phenylpropanesulfonate, 2-acrylamido-2-methylpropanesulfonic acid, Ν, dimethyl-dimethylaminopropylmethacrylamide, acrylic acid and methacrylic acid, and from the group of hydrophobic monomers including methyl methacrylene, acrylonitrile, acrylonitrile, acrylonitrile, Nn-butylacrylamide, Nn-hexylacrylamide and ethyl acrylate; absorbed water in the range of eight to 100 times by weight. of this composition at an ambient temperature of 25 ° C and a wt. the absorbed water ranges from 1 to 20 times by weight. at the transition point of the agent corresponding to the temperature at which the agent stops shrinking, and then the absorbed water composition contracts to release the absorbed water even in the presence of a large excess of water. 2. The method of claim 1, wherein said composition is added to an aqueous solution or emulsion and, after water absorption, said water-containing composition is separated from the aqueous solution or emulsion and exposed to an atmosphere above the transition point temperature of said agent. the released water separates from said reagent, which is recycled.