WO2012140981A1

WO2012140981A1 - Water-soluble ionic polymer and method for producing same

Info

Publication number: WO2012140981A1
Application number: PCT/JP2012/056222
Authority: WO
Inventors: 剛本多; 茂澤山
Original assignee: ハイモ株式会社
Priority date: 2011-04-15
Filing date: 2012-03-12
Publication date: 2012-10-18
Also published as: JP5839412B2; JPWO2012140981A1

Abstract

By oxidatively decomposing an ion exchange resin or waste ion exchange resin having a sulfonic acid group, a carboxyl group, a quaternary ammonium group or the like or a water absorbent resin having a carboxyl group with an oxidant in an adequate amount under adequate reaction conditions, the resin can be converted into a water-soluble ionic polymer. According to the present invention, a water-soluble ionic polymer can be obtained with high yield from waste ion exchange resins that have rarely been reused, and thus the above-mentioned resins are reusable as water-soluble ionic polymers.

Description

Water-soluble ionic polymer and production method thereof

The present invention relates to a technique for converting a water-swellable and ionic water-insoluble resin into a water-soluble ionic polymer. More specifically, the present invention is water-swellable, and the ionic water-insoluble resin is water-soluble by the action of an oxidizing agent. The present invention relates to a water-soluble ionic polymer produced by appropriate oxidative decomposition so as to be converted into an ionic polymer, and a production method thereof. These water-swellable and water-soluble ionic polymers converted from ionic water-insoluble resins can be reused for industrial applications.

Currently, the solidification method, the incineration method, the landfilling method, etc. are known as the processing method of the waste ion exchange resin, which is a used ion exchange resin, all of them from the viewpoint of material reuse or carbon dioxide emission. It is not preferable. As a method of treating a radioactive ion exchange resin, a method of oxidative decomposition using iron ions, copper ions or the like as a catalyst in the presence of hydrogen peroxide is known (Patent Documents 1 and 2). All of these are decomposed until they become gaseous products and liquid products to reduce the volume of waste, and are not intended to reuse the ion exchange resin. In addition, a method of decomposing in supercritical water and recovering an oil component has been proposed, but the recovered oil component is only reused as fuel, which is insufficient from the viewpoint of substance reuse (Patent Document 3). ). In addition, a method has been proposed in which the quaternary ammonium base of the ion exchange resin is biodegradable and detoxified by high temperature and high pressure, and the cross-linked polymer skeleton is reused as fuel. It is sufficient (Patent Document 4). These are all decomposed under severe conditions such as using a large amount of hydrogen peroxide, and no reusable water-soluble ionic polymer has been obtained.

In Patent Document 1, hydrogen peroxide is used in a large excess of about 4 to 40 times the mass of waste ion exchange resin 1, which is considered to be mainly for the purpose of decomposing water and carbon dioxide. It is done. Further, Patent Document 2 cannot accurately grasp the amount of hydrogen peroxide relative to the waste ion exchange resin used. Therefore, it is considered that no method for producing a water-soluble ionic polymer from a waste ion exchange resin with an appropriate amount of an oxidizing agent is found at present.

On the other hand, as for the treatment of the water-absorbing resin, the incineration treatment is currently mainstream. Patent Document 5 has a main problem of facilitating the incineration process by blending a polyvalent metal compound capable of preventing melting and solidification of the superabsorbent resin and adhesion to the incinerator during the incineration process. . In Patent Document 6, in order to facilitate separation of the paper plastic film and the water absorbent resin in the waste, a salt of a divalent or higher polyvalent metal ion is added to the waste containing the water absorbent resin, and the water A method of aggregating a water absorbent resin is disclosed. Patent Document 7 discloses that a gel substance is liquefied by adding an inorganic ionic metal salt composition liquid to a cloth or paper containing a water-swelled gel substance and having a mass ratio of about 0.1%. A method of liquefying and dehydrating is described. However, this operation only reduces the swelling degree of the water-absorbent resin by adding salts to reduce the apparent viscosity, and does not solve the problem. These prior documents need to be finally incinerated, and do not lead to a reduction in environmental load. Furthermore, the present applicant has proposed a method for producing a low molecular weight polymer by molecular cleavage using an oxidizing agent (Patent Document 8), but the polymer used is limited to a water-soluble polymer. In addition, since a catalyst made of metal ions is basically unnecessary, it is not directly related to the present invention.
Japanese Laid-Open Patent Publication No. 58-072099 JP 2000-065986 A Japanese Patent Laid-Open No. 11-049889 JP 2007-297455 A JP 2000-136314 A JP 2000-246011 A JP 2002-206084 A International Publication No. 2004-074331

As described above, the reuse of the waste ion-exchange resin or the waste water-absorbing resin has not been performed by a known method at all or is extremely insufficient. The present invention provides various industrially reusable water-soluble ionic properties by appropriately decomposing an ion exchange resin or a used waste ion exchange resin, or a water absorbent resin or a used waste water absorbent resin by an oxidation reaction. The subject is a method of converting to a polymer.

Water is obtained by oxidatively decomposing an ion-exchange resin or waste ion-exchange resin having a sulfonic acid group, a quaternary ammonium base, or the like, or a water-absorbing resin or waste water-absorbing resin having a carboxyl group or the like under an appropriate condition with an oxidizing agent. These water-soluble ionic polymers are very useful industrially, and are expected to be reusable for various purposes. Further, from the viewpoint of raw material procurement, the target water-soluble ionic polymer can be produced from inexpensive raw materials, and cost reduction can be achieved.

In the invention of claim 1, a water-swellable water-insoluble resin having an ionic group made of an addition polymer of vinyl monomer or a grafted product to which vinyl monomer is added is oxidized and decomposed with an oxidizing agent to make water-soluble. It is a water-soluble ionic polymer characterized by the above.

The invention of claim 2 is characterized in that the water-insoluble resin is a cation exchange resin, hydrogen peroxide is used as the oxidizing agent in a mass of 0.01 to 1.5 times the dry mass of the cation exchange resin, and the catalyst. The water-soluble ionic polymer according to claim 1, wherein iron ion or copper ion is used in a mass of 0.0001 to 0.01 times by mass with respect to the dry mass of the cationic ion exchange resin.

According to a third aspect of the present invention, the water-insoluble resin is an anion exchange resin, and at least one selected from peroxodisulfate and hydrogen peroxide is used as the oxidizing agent, and the oxidation is performed with respect to the dry mass of the anion exchange resin. The water-soluble ionic polymer according to claim 1, wherein the agent is used in an amount of 0.01 to 1.5 times by mass.

According to a fourth aspect of the present invention, the water-insoluble resin is a water-absorbing resin, and at least one selected from peroxodisulfate and hydrogen peroxide is used as the oxidizing agent, and the weight of the water-absorbing resin is based on the dry mass. The water-soluble ionic polymer according to claim 1, which is used in an amount of 0.003 to 3 times.

The invention of claim 5 is the water-soluble ionic polymer according to claim 2 or 3, wherein the cation exchange resin or the anion exchange resin is a waste ion exchange resin.

The invention of claim 6 is characterized in that the cation exchange resin has one or more monomer structural units selected from styrene, acrylic acid esters and methacrylic acid esters as a skeleton, has a sulfonic acid group or a carboxyl group, and is in water. 6. The water-soluble ionic polymer according to claim 2, which is a polymer compound that swells.

The invention according to claim 7 is characterized in that the anion exchange resin has one or more monomer structural units selected from styrene, acrylic ester and methacrylic ester as a skeleton, and a tertiary amino group or a quaternary ammonium base. The water-soluble ionic polymer according to claim 3, which is a polymer compound which swells in water.

The invention according to claim 8 is characterized in that the water-absorbent resin is a starch-acrylonitrile-acrylic acid graft copolymer, a starch-acrylic acid graft copolymer, a starch-acrylamide-acrylic acid graft copolymer, or a crosslinked sodium polyacrylate. The water-soluble ionic polymer according to claim 4, wherein the water-soluble ionic polymer is one or more selected from the group consisting of more than one.

The invention according to claim 9 is a water-swellable, water-swellable resin having an ionic group comprising a vinyl monomer addition polymer or a graft product to which a vinyl monomer has been added. A method for producing a water-soluble ionic polymer.

According to the present invention, a water-soluble ionic polymer can be obtained in high yield from an ion exchange resin, a waste ion exchange resin or a water absorbent resin, and a waste water absorbent resin that have hardly been reused in the past. It can be used. Further, from the viewpoint of raw material procurement, the target product can be manufactured with inexpensive raw materials, and cost reduction can be achieved.

First, the water-solubilization of the ion exchange resin will be described. As a matter of course, a new ion exchange resin before use can be used as the ion exchange resin used in the present invention, but it is particularly preferable to use a waste ion exchange resin from the viewpoint of recycling. The waste ion exchange resin referred to in the present invention is as follows. While ion exchange resins are repeatedly regenerated and used, organic contaminants are adsorbed on the surface of the resin particles, and this is difficult to desorb during regeneration or regenerative operations with high concentrations of acid or alkali. Reduces ion exchange capacity. Or, when the recycling is repeated, the crosslinking point is cut, the degree of crosslinking is lowered, the particles are excessively swollen, the raw water does not easily pass through the column, the processing amount is lowered, and this is a practical problem. Further, the resin particles are broken by collision and become finer and the processing amount is also reduced. The ion exchange resin deteriorated due to such various factors is constantly disposed of in practice and becomes a waste ion exchange resin. In the method for producing the water-soluble ionic polymer of the present invention, the raw ion exchange resin can be either a waste ion exchange resin or a new ion exchange resin. However, considering the growing awareness of environmental issues, it is very important to use waste ion exchange resins as raw materials, convert them as water-soluble ionic polymers, and apply them to new industrial applications. .

The present invention is described in detail below. Since the waste ion exchange resin may have various contaminants adsorbed on the resin surface, it may have to be pretreated before the oxidation reaction is performed. If necessary, after the treatment, 0.1 to 5 times the amount of water is added to the mass of the water-containing waste ion exchange resin and mixed. As necessary, an iron ion source and a copper ion source such as ferrous sulfate, ferrous chloride, ferric sulfate, ferric chloride, and cupric sulfate are added and dissolved as a catalyst. The amount of iron ions and copper ions added is 0.0001 to 0.01 times, preferably 0.0005 to 0.01 times the dry mass of the waste ion exchange resin. When the amount of the catalyst is less than this, the decomposition rate is lowered. When the amount of the catalyst is larger than this, it is difficult to control the reaction, and the amount obtained as the water-soluble ionic polymer is remarkably reduced. Along with these catalysts, hydrogen peroxide is used in an amount of 0.01 to 1.5 times, more preferably 0.05 to 1 times. Since hydrogen peroxide is generally sold as a 35% by mass aqueous solution, it is described as an addition amount of a 35% by mass aqueous solution in an amount of 0.03 to 4.5 times, more preferably 0.15 to 3 times. Use double amount. If the amount of hydrogen peroxide is less than this, the decomposition rate becomes low. If the amount of hydrogen peroxide is larger than this, it is difficult to control the reaction, and the amount obtained as a water-soluble ionic polymer is significantly reduced.

The reaction temperature is room temperature to 90 ° C, preferably 40 to 90 ° C. The reaction time is about 3 to 50 hours, with the disappearance of the solids of the ion exchange resin as a guide, depending on the amount of oxidizing agent and the amount of catalyst. This method is particularly effective for the decomposition of the cation exchange resin. This is probably because the cation exchange resin has an anion group, so that iron ions and copper ions are taken into the inside to favor the decomposition. Further, for example, when hydrochloric acid or the like is added at the time of decomposition to make it acidic, the decomposition is accelerated, and a water-soluble ionic polymer can be obtained with a smaller amount of hydrogen peroxide. After mixing the ion exchange resin, the metal ions as the catalyst, and hydrogen peroxide to form a uniform dispersed liquid, it is possible to stop the stirring and proceed the reaction without stirring. This method is a particularly effective process when carrying out the oxidation reaction at a high concentration. Accordingly, considering that the reaction is performed without stirring, the concentration of the oxidation reaction is 10 to 50% by mass, preferably 15 to 40% by mass, as the ion exchange resin concentration in the dispersion.

Another method for obtaining a water-soluble ionic polymer is a method using peroxodisulfate. Add 0.1 to 5 times the amount of water by weight to the water-containing waste ion exchange resin and mix. Here, peroxodisulfate is added as peroxodisulfate ions in an amount of 0.01 to 1.5 times, more preferably 0.05 to 1 times the dry mass of the waste ion exchange resin. If the amount of peroxodisulfate is less than this, the decomposition rate is lowered. If the amount of peroxodisulfuric acid is larger than this, it is difficult to control the reaction, and the amount obtained as a water-soluble ionic polymer is remarkably reduced. As peroxodisulfate, potassium peroxodisulfate, sodium peroxodisulfate, ammonium peroxodisulfate and the like can be used. The decomposition temperature is 40 to 100 ° C., preferably 60 to 90 ° C. The reaction time is determined based on the disappearance of the solid matter of the ion exchange resin, but is approximately 1 to 80 hours, preferably 5 to 40 hours. This method is particularly effective for the decomposition of anion exchange resins. This is presumably because the anion exchange resin has a cationic group, so that peroxodisulfate ions are taken into the inside and favorably decomposed. Even when the oxidation reaction is carried out using peroxodisulfate, it can be carried out without stirring as in the case of carrying out using hydrogen peroxide and a metal ion catalyst. The concentration of the ion exchange resin in the dispersion is 10 to 50% by mass, preferably 15 to 40% by mass.

The water-soluble ionic polymer produced by oxidation of the ion exchange resin or waste ion exchange resin of the present invention is usually a water-soluble ionic polymer having a weight average molecular weight of several thousand to several hundred thousand. And if you try to make something higher than hundreds of thousands,
This is possible by reducing the amount of oxidant used, but the reaction is slow and is not very practical. Therefore, the preferred range of the weight average molecular weight that can be produced in the present invention is from several thousand to several hundred thousand, more preferably from several thousand to 100,000.

The ion exchange resin used as a raw material used in the present invention is not particularly limited.
It is a polymer compound having a granular anionic group or cationic group that is insoluble in water and swells in water. Examples of the monomer used as a raw material for polymerizing these ionic polymer compounds include styrene and its derivatives. Specific examples include styrene, o-methylstyrene, p-methylstyrene, m-methylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, pn-butylstyrene, p-tert-butylstyrene, and pn. -Alkyl styrene such as hexyl styrene and pn-octyl styrene; alkoxy styrene such as p-methoxy styrene; aryl styrene such as p-phenyl styrene; halogeno styrene such as p-chloro styrene and 3,4-dichloro styrene; And halogenoalkyl styrene such as chloromethyl styrene, chlorobutyl styrene and bromobutyl styrene.

Acrylic acid or methacrylic acid esters can also be used. Specific examples include acrylic acid, methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, propyl acrylate, n-octyl acrylate, acrylic Dodecyl acid, stearyl acrylate, phenyl acrylate, and the like, methacrylic acid, methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, 2-methacrylic acid 2- Examples thereof include ethylhexyl, stearyl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, dimethylaminomethyl methacrylate and the like.

Furthermore, polyvinyl aromatic compounds used as crosslinking agents include styrene derivatives such as divinylbenzene, divinyltoluene, divinylxylene, trivinylbenzene, bisvinylbiphenyl, bisvinylphenylsulfone, bisvinylphenylethane, and bisvinylphenylbutane, ethylene Examples thereof include acrylic derivatives such as glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, and glycerol di (meth) acrylate.

As a polymerization method, copolymerization of a monovinyl aromatic compound such as styrene with a polyvinyl aromatic compound such as divinylbenzene, and a third vinyl compound used as necessary can be performed by a known method. . Usually, a mixture of all raw material monomers is subjected to suspension polymerization in the presence of a polymerization initiator in accordance with a known method to obtain a spherical crosslinked copolymer.

As a method of introducing an ionic group, there are a method of modifying after polymerization and a method of copolymerizing an ionic monomer, and a method of polymerizing the styrene monomer together with a crosslinking agent and modifying after polymerization. Many are taken. Anionic ion exchange resins that introduce cationic groups can be added to the polymer by adding chloromethyl methyl ether together with a Friedel Crafts catalyst such as anhydrous zinc chloride to chloromethylate the benzene ring, and then quaternary ammonium with trimethylamine or the like. Convert to base and introduce cationic group.

Moreover, the cationic ion exchange resin which introduce | transduces an anionic group uses a solvent, such as nitrobenzene, and swells a polymer, Then, sulfonation of a benzene ring is implemented with concentrated sulfuric acid, and an anionic group is introduce | transduced. When a weak anionic group such as a carboxyl group is introduced, a method of copolymerizing acrylonitrile and divinylbenzene and hydrolyzing it into a carboxyl group after polymerization is employed.

Therefore, the ion exchange resin used in the present invention is insoluble in water in which a quaternary ammonium base or a sulfonic acid group is added to the skeleton of a hydrophobic monomer structural unit such as styrene, acrylate ester or methacrylate ester, It is a polymer compound having an ionic group that swells in water.

In addition, the shape and form of the ion exchange resin are not particularly limited, and any shape such as a plate shape, a membrane shape, a fiber shape, and a spherical shape can be used, and a gel shape, a porous shape, a high porous shape, and an enlarged mesh shape are usable. Any form such as shape can be used. Further, the average particle diameter is not particularly limited, but those having a range of 100 μm to 2 mm are usually used as raw materials.

Next, the production of the water-soluble ionic polymer by the oxidation reaction of the water absorbent resin will be described.
In the present invention, the water-absorbing resin is intended for all water-absorbing resins having the above-mentioned problems, but more specifically, it is used for manufacturing water-absorbing articles such as paper diapers. Water-absorbing resin, that is, polymer such as sodium polyacrylate cross-linked product, sodium polysulfonate cross-linked product, copolymer such as acrylic acid, sulfonic acid and vinyl alcohol, and the monomer and cellulose, starch, etc. And the graft polymer of carboxymethyl and the like. These are generally crosslinked and are alkali metal salts. Specifically, starch-acrylonitrile graft copolymer, starch-acrylic acid graft copolymer, starch-acrylamide graft copolymer, cellulose-acrylonitrile graft copolymer, carboxymethylcellulose cross-linked product, sodium polyacrylate cross-linked product, Examples thereof include sodium acrylate-vinyl alcohol copolymer, N-substituted acrylamide cross-linked product, polyvinyl alcohol cross-linked product, polyvinyl alcohol freezing / thawing water absorbing gel, and the like. These water-absorbent resins can be used as new water-absorbent resins before being processed into paper diapers and sanitary products, and after being processed and used as paper diapers and sanitary products, paper and pulp are removed. It is also possible to use a water-absorbing resin that has been washed appropriately. In addition, it is preferable to use a sodium polyacrylate crosslinked body, which is the most common and inexpensive, from the viewpoint of chemical composition, as a raw material for the oxidation reaction.

The water-absorbing resin used in the present invention will be described below with reference to a crosslinked polymer of a water-soluble anionic monomer or a crosslinked copolymer with a nonionic monomer. The ionicity is generally anionic with little influence on a living body, and examples of such monomers include (meth) acrylic acid, 2- (meth) acrylamido-2-methylpropanesulfonic acid, or those And nonionic monomers such as (meth) acrylamide, N, N-dimethylacrylamide, 2-hydroxyethyl (meth) acrylate, N-methylol (meth) acrylamide, and the like, each of which may be used alone. Alternatively, two or more kinds may be mixed and used. Examples of the alkali metal in the alkali metal salt include lithium, sodium, and potassium. Since the water-soluble ethylenically unsaturated monomer is easily available industrially, (meth) acrylic acid and its alkali metal salt or (meth) acrylamide are often used in many cases.

Polyvinyl compounds used as crosslinking agents are ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, glycerin di (meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, polyglycerin. Examples thereof include di (meth) acrylate and N, N′-methylenebisacrylamide, and N, N′-methylenebisacrylamide is preferable.

For the polymerization, a granular material can be obtained by reverse phase suspension polymerization using the above monomer. In this case, examples of the solvent include aliphatic hydrocarbon compounds such as n-hexane, n-heptane, and ligroin; alicyclic hydrocarbon compounds such as cyclopentane, methylcyclopentane, cyclohexane, and methylcyclohexane; benzene, toluene, Examples thereof include aromatic hydrocarbon compounds such as xylene, and these may be used alone or in admixture of two or more. Among them, n-hexane, n-heptane and cyclohexane are preferred because they are easily available industrially, have stable quality and are inexpensive. Further, the surfactant is preferably a sucrose fatty acid ester, sorbitol fatty acid ester, polyoxyethylene alkylphenyl ether, etc., in combination with a polymer protective colloid,
Examples include ethyl cellulose, ethyl hydroxyethyl cellulose, polyethylene oxide, anhydrous maleated polyethylene, anhydrous maleated polybutadiene, anhydrous maleated EPDM (ethylene / propylene / diene / terpolymer) and the like, and they may be used alone, Two or more kinds may be mixed and used.

The average particle diameter of the water-absorbent resin particles thus obtained is usually from the viewpoint of preventing gel blocking due to fine powder in the absorbent article, and preventing the gritty feeling due to coarse particles, and improving the flexibility of the absorbent body. It is desirable that the thickness is 100 to 600 μm, preferably 200 to 500 μm.

As another method for producing the composition, starch-acrylonitrile graft copolymer and starch-acrylamide graft copolymer are graft-polymerized with acrylonitrile or acrylamide in the presence of starch. Introduce. In the case of a crosslinked carboxymethyl cellulose and a crosslinked polyvinyl alcohol, these water-soluble polymers are crosslinked by various methods to form a polymer gel.

Next, the operation of water solubilization by oxidation reaction will be described. New water-absorbing resin before processing, or used water-absorbing resin, after necessary separation and washing treatment, add 1 to 10 times the amount of water to the weight of the dried water-absorbing resin And mix. As necessary, an iron ion source and a copper ion source such as ferrous sulfate, ferrous chloride, ferric sulfate, ferric chloride, and cupric sulfate are added and dissolved as a catalyst. The amount of iron ions or copper ions added is 0.00005 to 0.02 times, preferably 0.0001 to 0.01 times the dry weight of the water absorbent resin. In the case of decomposition of the water absorbent resin, it is possible to carry out the decomposition even if no iron ion or copper ion is added, but the reaction proceeds quickly by using the iron ion or copper ion together and used. Is preferred. The water-absorbing resin is generally an anionic polymer, and it is considered that these iron ions or copper ions are adsorbed on the water-absorbing resin and promote the oxidative decomposition reaction. Further, hydrogen peroxide is added in an amount of 0.003 to 1.5 times, more preferably 0.03 to 1 times by mass. In the case of 35% hydrogen peroxide solution, it is added in an amount of 0.009 to 4.3 times, more preferably 0.09 to 2.9 times by mass. If the amount of hydrogen peroxide is less than this, the decomposition rate becomes low. If the amount of hydrogen peroxide is larger than this, it is difficult to control the reaction, and the amount obtained as a water-soluble ionic polymer is significantly reduced.

The reaction temperature is room temperature to 90 ° C, preferably 40 to 90 ° C. The reaction time is about 1 to 50 hours, based on the disappearance of the water-absorbent resin solids, depending on the amount of oxidizing agent and the amount of catalyst. Further, for example, when hydrochloric acid or the like is added at the time of decomposition to make it acidic, the decomposition is accelerated, and a water-soluble ionic polymer can be obtained with a smaller amount of hydrogen peroxide. After mixing the water-absorbing resin, the metal ions as the catalyst, and hydrogen peroxide to form a uniform dispersed liquid, it is possible to stop the stirring and proceed the reaction without stirring. This method is a particularly effective process when carrying out the oxidation reaction at a high concentration. Accordingly, considering that the reaction is performed without stirring, the concentration of the oxidation reaction is 10 to 50% by mass, preferably 15 to 40% by mass, as the ion exchange resin concentration in the dispersion.

Another method for obtaining a water-soluble ionic polymer is a method using peroxodisulfate. Add 1 to 10 times the amount of water by weight to the dried water-absorbent resin and mix. Here, peroxodisulfate is added in an amount of 0.003 to 3 times, more preferably 0.01 to 2 times the dry weight of the water absorbent resin. If the amount of peroxodisulfate is less than this, the decomposition rate is lowered. If the amount of peroxodisulfuric acid is larger than this, it is difficult to control the reaction, and the amount obtained as a water-soluble ionic polymer is remarkably reduced. As peroxodisulfate, potassium peroxodisulfate, sodium peroxodisulfate, ammonium peroxodisulfate and the like can be used. The decomposition temperature is 40 to 100 ° C., preferably 60 to 90 ° C. The reaction time is determined based on the disappearance of the water-absorbent resin, but is approximately 1 to 80 hours, preferably 3 to 40 hours. In this case, the concentration of the oxidation reaction is 10 to 50% by mass, preferably 15 to 40% by mass as the water-absorbing resin concentration in the dispersion.

The water-soluble anionic polymer produced by the water-absorbing resin or waste water-absorbing resin oxidizing agent of the present invention is usually a water-soluble ionic polymer having a weight average molecular weight of several thousand to several hundred thousand. Further, when trying to produce a product higher than several hundred thousand, it can be achieved by reducing the amount of the oxidizing agent used, but the reaction becomes slow and is not very practical. Therefore, the preferred range of the weight average molecular weight that can be produced in the present invention is from several thousand to several hundred thousand, more preferably from several thousand to 100,000.

Water-soluble polymers with ionic groups include coagulants, flocculants, concrete additives, fluidizing agents, ink fixing agents, dye fixing agents, dye fixing agents, detergent builders, antistatic agents, scale inhibitors, etc. Industrial applications. According to the method of the present invention, it is possible to convert a waste ion exchange resin into a water-soluble ionic polymer applicable to these uses.

Here, the ion equivalent value is an ion equivalent value with respect to 1 g of the water-soluble ionic polymer in the decomposition solution produced by decomposing 1 g of the water-insoluble resin dry mass, and is a value obtained by colloid titration. For colloidal titration, an automatic potentiometric titrator AT-510 (manufactured by Kyoto Denshi) incorporating a streaming potential detector PCD-500 (manufactured by Kyoto Denshi) was used. At the time of titration, an aqueous polyvinyl sulfonate solution was used for titration of the cationic water-soluble polymer, and an aqueous polydiallyldimethylammonium chloride solution was used for titration of the anionic water-soluble polymer.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples unless it exceeds the gist.

(Measurement of molecular weight)
The molecular weight of the water-soluble ionic polymer obtained by decomposition was determined as the molecular weight in terms of polyethylene glycol by GPC. A GPC apparatus manufactured by JASCO was used, and a G3000PW manufactured by Tosoh Corporation was used as a column. The eluent was a buffer of 1M acetic acid and 1M sodium acetate 1: 1 mixture and eluted at a flow rate of 0.5 ml / min.

Example 1
0.051 g of ferrous sulfate heptahydrate is dissolved in 37.6 g of demineralized water, and 42.6 g of cation exchange resin SK1B (manufactured by Mitsubishi Chemical Corporation) in a water-containing state (mass after drying of 20.0 g) is added and dispersed therein. I let you. 20.0 g of 35% hydrogen peroxide was added and held at 80 ° C. for 3 hours. The cation exchange resin was completely dissolved. Demineralized water was added to the resulting solution to make 100 g, and a 20% water-soluble ionic polymer aqueous solution was obtained. A part was sampled from here, and the ion equivalent value was determined by colloid titration. The obtained water-soluble ionic polymer had an ion equivalent value of 4.7 meq / g. The weight average molecular weight was 4400. This is Prototype-1.

In the same manner, water-soluble ionic polymers having physical properties such as Trial Production-2 to Trial Production-14 were produced using the oxidizing agent, catalyst and ion exchange resin shown in Table 1. These results are shown in Table 1.

(Table 1)

Catalyst (iron ion, copper ion) is a mass ratio of ions to 1 g of dry ion exchange resin, and hydrogen peroxide and peroxodisulfate are added in a mass ratio of 1 g of dry ion exchange resin. Hydrogen peroxide; 35% aqueous solution, product ion equivalent value; meq / g,
FS; Ferrous sulfate heptahydrate, HPO; Hydrogen peroxide, APD; Ammonium peroxodisulfuric acid, FR; Ferric sulfate, FC; Ferrous chloride tetrahydrate, CS; Copper sulfate.

(Example 2)
Dissolved 0.001 g of ferrous sulfate heptahydrate in 80 g of demineralized water, added 0.3 g of 35% hydrogen peroxide, and dried the water-absorbent resin (cross-linked sodium polyacrylate) 10.0 g Was added. Initially, the water-absorbing resin absorbed all the aqueous solution and was in a solid state. Hold at 80 ° C. for 1.5 hours. The water absorbent resin was completely dissolved. The weight of the obtained solution was 101 g. A part was sampled from here, and the ion equivalent value was determined by colloid titration. The obtained water-soluble ionic polymer had an ion equivalent value of 11.5 meq / g. The weight average molecular weight was 205000. This is Prototype-15.

By a similar operation, trial production-16 to trial production-30 were produced using the oxidizing agent, catalyst and water-absorbing resin shown in Table 2. These results are shown in Table 2.

(Table 2)

Catalyst (iron ion, copper ion) is a mass ratio of ions to 1 g of dry ion exchange resin, and hydrogen peroxide and peroxodisulfate are added in a mass ratio of 1 g of dry ion exchange resin. Hydrogen peroxide; 35% aqueous solution, product ion equivalent value; meq / g,
FS; Ferrous sulfate heptahydrate, HPO; Hydrogen peroxide, APD; Ammonium peroxodisulfuric acid, FR; Ferric sulfate, FC; Ferric chloride hexahydrate, CS; Copper sulfate,
Cross-linked sodium polyacrylate (ACS), starch-sodium acrylate graft copolymer (SAS), sodium acrylate-vinyl alcohol copolymer (ASPV), starch-acrylamide-sodium acrylate graft copolymer (SAAS) .

By the method for producing the water-soluble ionic polymer of the present invention, an ion exchange resin or waste ion exchange resin having a sulfonic acid group, a carboxyl group, a quaternary ammonium group, or the like, or a water-absorbing resin having a carboxyl group can be appropriately oxidized. It can be converted into a water-soluble ionic polymer by oxidative decomposition under the amount of the agent and reaction conditions. This technique is a method for producing a water-soluble ionic polymer using a low-cost raw material, and is expected to be reusable for various applications, and has very high industrial applicability.

Claims

Water-soluble, water-insoluble resin having an ionic group consisting of an addition polymer of vinyl monomer or a grafted product to which vinyl monomer is added, and water-solubilized by oxidative decomposition with an oxidizing agent Ionic polymer.
The water-insoluble resin is a cation exchange resin, hydrogen peroxide is used as the oxidizing agent in a mass of 0.01 to 1.5 times the dry mass of the cation exchange resin, and iron ions or copper ions are used as a catalyst. The water-soluble ionic polymer according to claim 1, wherein the water-soluble ionic polymer is used in an amount of 0.0001 to 0.01 times by mass with respect to the dry mass of the cation exchange resin.
The water-insoluble resin is an anion exchange resin, and at least one selected from peroxodisulfate and hydrogen peroxide is used as the oxidizing agent, and the oxidizing agent is 0.01 by mass relative to the dry mass of the anion exchange resin. The water-soluble ionic polymer according to claim 1, wherein the water-soluble ionic polymer is used in an amount of up to 1.5 times.
The water-insoluble resin is a water-absorbing resin, and at least one selected from peroxodisulfate and hydrogen peroxide is used as the oxidizing agent, and used in a mass of 0.003 to 3 times the dry weight of the water-absorbing resin. The water-soluble ionic polymer according to claim 1, wherein
The water-soluble ionic polymer according to claim 2 or 3, wherein the cation exchange resin or the anion exchange resin is a waste ion exchange resin.
The cation exchange resin is a polymer compound having one or more monomeric structural units selected from styrene, acrylic acid esters and methacrylic acid esters as a skeleton, having a sulfonic acid group or a carboxyl group, and swelling in water. The water-soluble ionic polymer according to claim 2, wherein
The anion exchange resin has one or more monomer structural units selected from styrene, acrylic ester and methacrylic ester as a skeleton, and has a tertiary amino group or a quaternary ammonium base in the side chain and swells in water. The water-soluble ionic polymer according to claim 3, which is a polymer compound.
The water-absorbing resin is at least one selected from starch-sodium acrylate graft copolymer, starch-acrylamide-acrylic acid graft copolymer, cross-linked sodium polyacrylate, sodium acrylate-polyvinyl alcohol copolymer. The water-soluble ionic polymer according to claim 4, wherein the water-soluble ionic polymer is present.
In aqueous medium, water-swellable water-insoluble resin having an ionic group consisting of an addition polymer of vinyl monomer or a grafted product of vinyl monomer is oxidized and decomposed with an oxidizing agent to make it water-soluble. A method for producing a water-soluble ionic polymer characterized by the above.