JPH11158341A - Method for producing superabsorbent polymer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing the subject polymer having excellent deodorizing effect on urine/human waste without impairing the water- absorbing performance inherent therein. SOLUTION: This method for producing the subject polymer comprises incorporating 100 pts.wt. of a highly water-absorbing polymer A formed by polymerizing water-soluble polymerizable monomer (s) in the presence of a crosslinking agent with 0.01-5 pts.wt. of a glycine-type amphoteric surfactant B in any stage after ending the polymerization; wherein it is preferable that acrylic acid and an alkali metal salt thereof accounts for >=50 wt.% of the above water-soluble polymerizable monomer(s).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for producing a superabsorbent polymer. More specifically, the present invention relates to a method for producing a superabsorbent polymer by adding a glycine-based amphoteric surfactant after completion of polymerization of a water-soluble polymerizable monomer. The superabsorbent polymer produced according to the present invention strongly suppresses the generation of malodorous substances such as ammonia by having a more excellent deodorant function without impairing the original water absorbing performance of the superabsorbent polymer composition. Can be. Therefore, it is very effective against bodily fluids such as urine, blood and sweat, as well as excretions such as stool, and is effectively used as a sanitary material for children's / adult paper diapers, sanitary products, and various pads. be able to.

[0002]

2. Description of the Related Art In recent years, superabsorbent polymers have been used not only in sanitary fields such as sanitary products and disposable disposable diapers, but also in various industrial products such as water-blocking materials, anti-condensation agents, freshness-retaining materials, and solvent dehydrating agents, as well as greening. It has also been put to practical use in the agricultural and horticultural fields, and its application range is expanding further. Among these fields of application, sanitary products such as sanitary products, disposable paper diapers and incontinence pads have recently been improved in wearing feeling due to improvements in materials used, draping, various gatherings, and the like, and the wearing time has been increasing. When a super absorbent polymer is used for disposable diapers,
The superabsorbent polymer gel that has absorbed urine generates malodorous substances such as ammonia and hydrogen sulfide due to propagation of bacteria and enzymes in the body fluid over time. In addition, when contacting with solid stool or absorbing liquid stool, the stool emits odors such as hydrogen sulfide, mercaptan, and indole.
Therefore, the appearance of a superabsorbent polymer excellent in deodorizing properties capable of removing these malodorous substances has been desired for the superabsorbent polymer.

As a method for removing malodorous substances generated from urine, JP-A-59-105448 discloses a method containing activated carbon, and JP-A-60-158861 discloses a leaf extract of a Camellia plant. Method, JP-A-1-5
JP-A-546-546 and JP-A-1-5547 disclose a method for containing an oxide of a specific metal, JP-A-2-41155 discloses a method for containing tea-making, and JP-A-5-277143.
In the publication, a method of including a metal complex and the like are proposed. However, the additives themselves are black or green in all of these additives, and often have an apparent problem. Moreover, the deodorizing ability when urine was actually absorbed was extremely low and was not satisfactory.

As a method of maintaining the deodorizing function even after urine is absorbed, Japanese Patent Application Laid-Open No. 7-157661 discloses a method.
A method for containing a maleimide is disclosed in JP-A-8-33237.
No. 9 proposes a method of containing sodium tetraborate and / or sodium metaborate, and Japanese Patent Publication No. 4-17058 proposes a method of containing benzalkonium chloride and / or chlorhexidine gluconate. However, maleimide used in Japanese Patent Application Laid-Open No. 7-157671 is expensive and has the disadvantage that it has corrosiveness itself. The sodium tetraborate / sodium metaborate used in JP-A-8-332379 has a low deodorizing effect and thus needs to be added in a large amount, and further has the disadvantage that the deodorizing effect is reduced depending on urine species. In addition, although benzalkonium chloride / chlorhexidine gluconate used in Japanese Patent Publication No. Hei 4-17058 shows high deodorant properties to urine containing no protein, when protein coexists like human urine, It has the disadvantage that the deodorant properties are greatly reduced.

[0005]

As described above, the conventional additives have a problem that the deodorizing function after absorbing urine is low, and the effect is reduced depending on the type of urine. An object of the present invention is to provide a method for producing a superabsorbent polymer having a high deodorizing effect when it comes into contact with urine and human waste without impairing the original appearance and water absorption performance of the superabsorbent polymer.

[0006]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, by adding a specific surfactant after polymerization of the superabsorbent polymer, urine / urine was added.
It has been found that a superabsorbent polymer having an excellent deodorizing effect on human waste can be obtained, and the present invention has been completed.

That is, the gist of the present invention is that glycine is added to 100 parts of a superabsorbent polymer (A) obtained by polymerizing a water-soluble polymerizable monomer in the presence of a crosslinking agent at an arbitrary stage after completion of the polymerization. 0.01 type amphoteric surfactant (B)
To 5 parts by weight of the superabsorbent polymer. Hereinafter, the present invention will be described in detail.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION (Water-soluble polymerizable monomer) As the water-soluble polymerizable monomer used in the present invention, basically any water-soluble polymerizable monomer can be used. Those are water-soluble ethylenically unsaturated monomers. Specific examples of the water-soluble polymerizable monomer include, for example, acid-containing monomers such as a polymerizable monomer having a carboxyl group and a polymerizable monomer having a sulfone group, and salts thereof.

The polymerizable monomer having a carboxyl group includes, for example, unsaturated mono- or polycarboxylic acids and their anhydrides. Specific examples thereof include (meth) acrylic acid, ethacrylic acid, crotonic acid, and the like. Sorbic acid, maleic acid, itaconic acid, cinnamic acid and the like. Here, the term “(meth) acryl” is
It means both “acryl” and “methacryl”.

Examples of the polymerizable monomer having a sulfonic acid group include an aliphatic or aromatic vinyl sulfonic acid, and specific examples thereof include vinyl sulfonic acid, allyl sulfonic acid, vinyl toluene sulfonic acid, styrene sulfonic acid,
(Meth) acrylsulfonic acid, such as sulfoethyl (meth) acrylate, sulfopropyl (meth) acrylate,
(Meth) acrylamidosulfonic acid, such as 2-acrylamido-2-methylpropanesulfonic acid, and the like.

Other water-soluble polymerizable monomers include non-ionic monomers such as (meth) acrylamide, 2-hydroxyethyl (meth) acrylate, N, N-dimethylacrylamide and N-methylol (meth) acrylamide; Examples thereof include amino group-containing polymerizable monomers such as diethylaminoethyl (meth) acrylate and dimethylaminopropyl (meth) acrylate, and quaternized products thereof, and one or more kinds selected from these groups can be used. .

Among the above water-soluble polymerizable monomers, it is preferable to use acrylic acid as a main component in view of the performance and cost of the resulting superabsorbent polymer. In that case, acrylic acid or acrylic acid occupying in all monomer components is preferably used. The proportion of the salt is at least 50% by weight, preferably at least 70%.
% By weight. The concentration of the acrylic acid (salt) monomer in the aqueous solution is usually 20% by weight or more, preferably 25% by weight to a saturated concentration. Acrylic acid is used in a form in which a part or all of the acrylic acid is neutralized with an alkali metal compound or an ammonium compound. At this time, the ratio of neutralization (referred to as a degree of neutralization) is preferably 30 to 100 mol%. , More preferably 50 to 90 mol%.

As the alkali metal salt, a sodium salt or a potassium salt is preferable in view of the performance of the obtained superabsorbent polymer, industrial availability, safety and the like. This neutralization may be performed at any stage of producing the superabsorbent polymer, for example, neutralization at the polymerizable monomer stage,
Alternatively, there is a method such as neutralization in the state of a hydrogel which is a polymerization product.

(Crosslinking agent) The above-mentioned water-soluble polymerizable monomer, particularly acrylic acid-based monomer, becomes a highly water-absorbing polymer by generating a certain amount of self-crosslinking without using any crosslinking agent. In order to keep good, it is necessary to add a crosslinking agent component to the aqueous monomer solution. Examples of the crosslinking agent used in the present invention include a crosslinking agent having two or more polymerizable unsaturated groups and / or reactive functional groups. Examples of the crosslinking agent having two or more polymerizable unsaturated groups include di- or tri (meth) acrylic polyols such as ethylene glycol, propylene glycol, trimethylolpropane, glycerin, polyoxyethylene glycol, polyoxypropylene glycol, and polyglycerin. Acid esters, unsaturated polyesters obtained by reacting the polyols with unsaturated acids such as maleic acid and fumaric acid, N,
Bisacrylamides such as N'-methylenebisacrylamide, di- or tri (meth) acrylates obtained by reacting polyepoxide with (meth) acrylic acid, polyisocyanates such as tolylene diisocyanate, hexamethylene diisocyanate and (meth) ) Di (meth) obtained by reacting acrylic acid hydroxyester
Carbamyl acrylates, allylated starch,
Allylated cellulose, diallyl phthalate, other tetraallyloxyethane, pentaeristol triallyl ether, trimethylolpropane triallyl ether,
Examples include polyvalent allyls such as diethylene glycol diallyl ether and triallyl trimellitate. Among them, in the present invention, ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, N, N'-methylenebis (meth) acrylamide and the like are usually used.

Examples of the crosslinking agent having two or more reactive functional groups include diglycidyl ether compounds, haloepoxy compounds and isocyanate compounds. Among these, a diglycidyl ether compound is particularly preferred.
Specific examples of the diglycidyl ether compound include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, glycerin diglycidyl ether, polyglycerin diglycidyl ether, and the like. Among them, ethylene glycol diglycidyl ether is preferable. Other haloepoxy compounds include epichlorohydrin, β-methylepichlorohydrin, and the like, and isocyanate compounds include 2,4-tolylene diisocyanate, hexamethylene diisocyanate, and the like.
It can be used in the present invention. The amount of the crosslinking agent to be used is generally 0.001 to 10% by weight, preferably 0.01 to 5% by weight, based on the water-soluble polymerizable monomer. Further, in addition to the crosslinking agent, a method of forming a crosslinking by graft polymerization may be used in combination. As such a method, cellulose, starch, a water-soluble polymerizable monomer is polymerized in the presence of a hydrophilic polymer such as polyvinyl alcohol,
A method of forming a crosslink resulting from graft polymerization during the polymerization may be mentioned, and it is preferable to use these water-soluble polymers in a range of 1 to 30% by weight based on the water-soluble polymerizable monomer.

(Polymerization method of superabsorbent polymer) The polymerization method in the present invention may be a conventionally known method.
For example, an aqueous solution polymerization method using a radical polymerization initiator, a reverse phase suspension polymerization method, a suspension polymerization method, and the like can be mentioned. Also radiation,
A method of irradiating an electron beam, ultraviolet light, or the like to perform polymerization may be employed. Industrially, an aqueous solution polymerization method using a radical polymerization initiator and a reverse phase suspension polymerization method are preferred. When a radical polymerization initiator is used, specific examples of the initiator include inorganic peroxides (hydrogen peroxide, ammonium persulfate, potassium persulfate, sodium persulfate, etc.) and organic peroxides (benzoyl peroxide, dibenzoyl peroxide, etc.). -T-butyl peroxide, cumene hydroxy peroxide, succinic peroxide, di (2-ethoxyethyl) peroxydicarbonate, etc., azo compounds (azobisisobutylnitrile, azobiscyanovaleric acid, 2,2′-azobis ( 2-amidinopropane) hydrochloride, etc.) and a redox catalyst (reducing agent such as alkali metal sulfite or bisulfite, ammonium sulfite, ammonium bisulfite, ascorbic acid) and alkali metal persulfate, ammonium persulfate, peroxide Consisting of a combination of oxidizing agents such as And the like. These initiators may be used as a mixture. The amount of these initiators to be used is generally 0.0001 to 5% by weight, preferably 0.0005 to 1% by weight, based on the total amount of the water-soluble polymerizable monomer and the crosslinking agent.

In the case of the inverse suspension polymerization method, first, an aqueous solution of a water-soluble polymerizable monomer is prepared by using a water-soluble radical polymerization initiator in a hydrophobic solvent containing a W / O type emulsifier in the presence of a crosslinking agent. Perform reverse phase suspension polymerization. Due to polymerization, usually an average of 1
A slurry mixture of 0-300μ hydrogel, excess emulsifier and hydrophobic solvent is obtained. As the polymerization method at this time, any of a batch polymerization method in which the monomer aqueous solution is charged into the reactor at once from the beginning and a dropping method in which the monomer aqueous solution is dropped into a hydrophobic solvent can be used. The slurry after polymerization is subjected to surface treatment or the like as necessary through direct dehydration or azeotropic dehydration with a hydrophobic solvent by a known method,
It becomes a product after drying and sieving.

In this case, the W / O type emulsifier used is
Any one can be used as long as it is soluble or has an affinity for a hydrophobic solvent and basically forms a W / O emulsion system. Specifically, such an emulsifier generally has an HLB of 1 to 1.
9, preferably less than 2 to 7 nonionic and / or anionic. Specific examples of the emulsifier include sorbitan fatty acid ester, polyoxysorbitan fatty acid ester, sucrose fatty acid ester, polyglycerin fatty acid ester, polyoxyethylene alkyl phenyl ether, ethyl cellulose, ethyl hydroxyethyl cellulose, oxidized polyethylene, anhydrous maleated polyethylene, Maleic anhydride polybutadiene, maleic anhydride ethylene propylene diene terpolymer, a copolymer of α-olefin and maleic anhydride or a derivative thereof, such as polyoxyethylene alkyl ether phosphoric acid, may be mentioned. These emulsifiers are used in an amount of 0.0
It is 5 to 10% by weight, preferably 0.1 to 1% by weight.

Any hydrophobic solvent can be used as long as it is basically insoluble in water and inert to polymerization. Examples thereof include aliphatic hydrocarbons such as n-pentane, n-hexane, n-heptane and n-octane; alicyclic hydrocarbons such as cyclohexane and methylcyclohexane; and aromatic hydrocarbons such as benzene, toluene and xylene. And the like. N-hexane, n-heptane, and cyclohexane can be mentioned as preferred solvents in view of the stability, quality and the like of industrial availability. The amount of these hydrophobic solvents used is 0.5 to 10 times by weight based on the aqueous solution of the water-soluble ethylenically unsaturated monomer used in the first stage,
Preferably, 0.6 to 5 times by weight is employed.

Incidentally, in the case of the aqueous solution polymerization method, a known method (Japanese Patent Application Laid-Open No. 55-84304, Japanese Patent Application Laid-Open No.
), A superabsorbent polymer can be produced. Although the superabsorbent polymer thus obtained has a relatively high deodorizing ability against malodorous substances (especially ammonia) in a powder state, it absorbed urine and gelled as in the case of using diapers. In this case, the ability to deodorize bad odors (ammonia, hydrogen sulfide, etc.) generated from urine / sewer is extremely low. As in the present invention, by adding a glycine-type amphoteric surfactant at any stage of drying or pulverization after polymerization,
A superabsorbent polymer having a high deodorizing ability even when urine / sewage is absorbed is obtained.

(Glycine type zwitterionic surfactant (B)) As the glycine type zwitterionic surfactant used in the present invention, alkyl di (aminoethyl) glycine hydrochloride, alkyl di (aminoethyl) glycine sodium salt, Alkyl polyalkylethyl glycine hydrochloride, di (alkylaminodiethyl) glycine hydrochloride and the like can be mentioned. From the viewpoint of easy handling and availability, the alkyl group of the above surfactant preferably has 12 to 18 carbon atoms. Specific examples of the surfactant include lauryl di (aminoethyl) glycine hydrochloride, myristyl di (aminoethyl) glycine hydrochloride, lauryl di (aminoethyl) glycine sodium salt, octyl polyalkylethyl glycine hydrochloride, and the like. Unlike quaternary ammonium salts such as benzalkonium chloride, glycine-type zwitterionic surfactants are characterized in that their deodorizing ability does not decrease even in the presence of proteins. The amount of the glycine-type zwitterionic surfactant used depends on the type, properties and average particle size of the superabsorbent polymer used, but is generally 0.01 to 100 parts by weight of the superabsorbent polymer.
-5 important parts, preferably 0.05-1 part by weight.
If the amount is less than 0.01 part by weight, the effect is not sufficiently exhibited, and if it exceeds 5 parts by weight, the effect on the amount used is saturated.

(Composite silicate compound (C)) In addition to the glycine-type amphoteric surfactant, an additive such as a composite silicate compound may be added to the superabsorbent polymer of the present invention. . The composite silicate compound used in the present invention is S
The iO ₂ are those containing in a range of 30 to 80 wt%. When the content of SiO _{2 in} the composite silicate compound is too large, although the deodorizing effect of ammonia is excellent, the deodorizing effect on amines such as trimethylamine, and sulfur-based malodorous components such as hydrogen sulfide and mercaptan is not sufficient. Not suitable because it is small. On the other hand, if the content of SiO ₂ is too small, the powder properties of the superabsorbent polymer, for example, the fluidity, tend to deteriorate.

The components other than SiO ₂ in the composite silicate compound include metal oxides such as Al ₂ O ₃ , ZnO, Ag ₂ O, and MgO. Among them, ZnO and / or Al ₂ O ₃ are preferable in terms of deodorizing performance and hue of the silicate compound, and ZnO is particularly preferable. The content of these metal oxides in the composite silicate compound is usually 20 to
70% by weight.

The average particle diameter of the composite silicate compound is as follows:
A smaller one is preferable because the surface area increases. In the present invention, for example, it is preferable to use one having a size of 50 μm or less, particularly 10 μm or less. The total amount of the surfactant (B) and the composite silicate compound (C) contained in the superabsorbent polymer of the present invention also depends on the type, properties, average particle size and the like of the superabsorbent polymer used. Although different, it is 0.05 to 10 parts by weight, preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the superabsorbent polymer. If the amount is too small, the deodorizing effect is insufficiently developed, and even if it is added excessively, the effect is not improved.

The weight ratio of the surfactant (B) and the composite silicate compound (C) contained in the superabsorbent polymer of the present invention is in the range of 10:90 to 90:10, Preferably it is in the range of 30:70 to 70:30. If the proportion of the surfactant (B) is too large, the deodorizing ability for urine is improved, but the deodorizing ability for feces is insufficient. On the other hand, if the proportion of the composite silicate (C) is too large, the improvement of the deodorizing ability for urine becomes insufficient.

(Method of adding glycine-type amphoteric surfactant) In the present invention, the glycine-type amphoteric surfactant may be added to the superabsorbent polymer at any stage after completion of the polymerization. When added before and during the polymerization, the suspension polymerization is not preferred because the polymerization itself may be destabilized or the glycine-type amphoteric surfactant may be deteriorated by the heat generated during the polymerization. In the present invention, the step of adding a glycine-type amphoteric surfactant to the superabsorbent polymer includes a step before polymerization, before drying, a step during drying, a step before pulverization after drying,
Stages during the milling and before reaching the product after the milling. The step of adding to the pearl-like hydrogel obtained by the reversed-phase suspension polymerization method includes, in addition to the steps described above, a glycine-type amphoteric surfactant in an organic solvent suspension at a step before the removal of the solvent after the polymerization. It is also possible to adopt a method in which the solution is added to a suspension to absorb the solution, or a method in which the solution is sprayed on the hydrogel at a stage after the removal of the solvent.

In the present invention, the glycine-type amphoteric surfactant may be added in the form of a stock solution, but is preferably added in the form of an aqueous solution or aqueous dispersion for uniform addition. Any method may be used as a method of adding at the stage before polymerization and before drying, as long as it can be added uniformly, for example, a method of immersing a hydrogel in the aqueous solution or dispersion, a method of spraying on a water-reduced gel, and stirring. A method of mixing and the like can be mentioned. Various methods can be used as a method of adding to the polymer in a stage before drying and before pulverization or in a stage before reaching to a product after pulverization, such as Nauta mixer, ribbon mixer, paddle mixer, kneader, air mix, conical. Examples thereof include a method using a blender such as a blender. In this case, it is preferable to spray or drop an aqueous solution or aqueous dispersion of the glycine-type amphoteric surfactant onto the polymer with stirring, but the method is not limited to these methods as long as uniform addition is possible.

In the present invention, when an aqueous solution or aqueous dispersion of a glycine-type amphoteric surfactant is added and mixed, it is heated and dried if necessary. The heating and drying temperature at this time is very important. The heating and drying temperature is usually 80 to 200 ° C, preferably 100 to 150 ° C. When drying is performed at less than 80 ° C., it is necessary to dry for a long time, which is not industrially preferable. When drying at a temperature exceeding 150 ° C., it is possible to finish the drying in a short time, but it is not preferable because the glycine-type amphoteric surfactant may be deteriorated. However, when drying under reduced pressure, the drying temperature can be set to less than 80 ° C. The method of heat drying may be a known method, such as a method of laminating on a perforated plate, a wire mesh, a flat plate, or a belt and performing batch or continuous hot air drying, a method of performing hot air drying in a fluidized drying furnace, a method of heating under reduced pressure and the like. Is mentioned.

The addition of the composite silicate compound (C) is based on the method of adding the glycine-type zwitterionic surfactant (B), either with the component (C) alone or with high water absorption together with the component (B). May be added to the hydrophilic polymer. The surface of the superabsorbent polymer powder obtained in the present invention may be subjected to a surface treatment by a usual method using a crosslinking agent such as a glycidyl ether compound, a silane compound or a polyvalent metal salt.

[0030]

The present invention will be described in more detail with reference to the following examples and comparative examples, but the present invention is not limited to the examples unless it exceeds the gist thereof. The following characteristic values of the superabsorbent polymer obtained in the examples were measured by the following methods. (Water absorption capacity) About 0.5 g of a water-absorbing polymer was precisely weighed,
Mesh nylon bag (20cm x 10cm size)
And immersed in 500 cc of artificial urine for 30 minutes. Thereafter, the nylon bag was pulled up, drained for 15 minutes, weighed, corrected for blank, and calculated water absorption capacity. The composition of the artificial urine is as follows. Urea 1.94% Sodium chloride 0.80% Calcium chloride 0.06% Magnesium sulfate 0.11% Pure water 97.09%

(Urine deodorant test) 4 g of a superabsorbent polymer was coated with a cotton nonwoven fabric (basis weight: 150 g / m ² , size 11).
× 8 cm). Furthermore, a nonwoven fabric made of the same material and the same size as the above nonwoven fabric is put on the nonwoven fabric to prepare a simple liquid absorbing pad. This liquid absorbing pad is placed in a 250 ml glass container with a lid, absorbs 100 g of adult human urine (mixed with human urine of 5 adults), covers, and is left in a constant temperature bath at a set temperature of 40 ° C. did. After being left for 72 hours, the off-flavor concentration inside the container was measured using a gas tube detector made by Gastec. The measured odor substances and the detector tube numbers used are as follows. Ammonia gas tech detector tube: 3L Hydrogen sulfide gas tech detector tube: 4LT

(Urine deodorant test) As human urine, human urine was used as a urine component, and chicken manure was pulverized as a stool component. First, for 1000g of adult human urine (mixed human urine of 5 adults)
50 g of ground chicken dung is mixed and left at room temperature for 3 hours. A liquid absorbing pad of the same type as that used in the urine deodorization test was placed in a 250-ml glass container with a lid, and 100 g of human urine (mixed with human urine of five adults) was absorbed. And left in a thermostat. After being left for 72 hours, the off-flavor concentration inside the container was measured using a gas tube detector made by Gastec. Ammonia gas tech detector tube: 3L Hydrogen sulfide gas tech detector tube: 4LT

EXAMPLE 1 1210 g of cyclohexane was placed in a 5000 ml four-necked round-bottom flask equipped with a stirrer, reflux condenser, temperature tube and nitrogen gas inlet tube, and sorbitan monostearate 9 was added.
After adding g to dissolve, nitrogen gas was blown in to expel dissolved oxygen. Separately, 350 g of acrylic acid was dissolved in 727.7 g of water while externally cooling 350 g of acrylic acid in a beaker having a capacity of 2000 ml.
Was added to neutralize 70% of the carboxyl groups. In this case, the monomer concentration with respect to water corresponds to 35% by weight as the monomer concentration after neutralization. Then, N, N'-methylenebisacrylamide was added to the mixture.
After 37 g and 0.94 g of potassium persulfate were added and dissolved, nitrogen gas was blown in to expel dissolved oxygen. The contents of the four-necked round-bottomed flask are added to the volume of 2000 ml.
The contents of the beaker were added, and the mixture was stirred and dispersed, and the inside temperature of the flask was raised by an oil bath while bubbling nitrogen gas. After a sufficient time, the temperature reached 75 ° C. Then, the mixture was reacted for 3 hours while stirring. After that, when stirring is stopped,
As the wet polymer particles settled to the bottom of the round bottom flask,
The cyclohexane phase was separated by decantation, and the separated wet polymer was transferred to a reduced-pressure drier and heated to 90 ° C. to remove the attached cyclohexane and water. As a result, 400 g of a smooth superabsorbent polymer was obtained. 100 g of the superabsorbent polymer was placed in a double-arm kneader, and while stirring, Levon 50 (manufactured by Sanyo Chemical Industries, Ltd., di (alkylaminoethyl) glycine hydrochloride, component concentration: 5)
0%, the alkyl group is C ₈ H ₁₇₎ a 2g and spraying an aqueous solution dissolved in water 100g was maintained for 15 minutes to liquid absorption to uniformly superabsorbent polymer. Thereafter, the polymer was taken out, transferred to a vacuum dryer again, and dried at 90 ° C. to obtain a powdery superabsorbent polymer composition. The above measurement was performed on the obtained superabsorbent polymer composition. Table 1 shows the results.

Example 2 A superabsorbent polymer composition was obtained in the same manner as in Example 1 except that the amount of di (alkylaminoethyl) glycine hydrochloride used in Example 1 was changed to 0.4 g. The above measurement was performed on the obtained superabsorbent polymer composition. Table 1 shows the results.

Example 3 In place of di (alkylaminoethyl) glycine hydrochloride in Example 1, alkyl di (aminoethyl) glycine hydrochloride Levon LAG-40 (manufactured by Sanyo Chemical Industries, Ltd., component concentration: 40%, alkyl group is C ₁₂ H ₂₅ /
Except that the C ₁₄ H ₂₉₎ was used 2.5g in the same manner as in Example 1 to obtain a superabsorbent polymer composition. The above measurement was performed on the obtained superabsorbent polymer composition. Table 1 shows the results
Shown in

Example 4 In place of di (alkylaminoethyl) glycine hydrochloride in Example 1, levon 15 (sodium salt of lauryl di (aminoethyl) glycine) (manufactured by Sanyo Chemical Industries, Ltd.)
(Manufacturing, component concentration: 30%) in the same manner as in Example 1 except that 3.3 g of a superabsorbent polymer composition was obtained. The above measurement was performed on the obtained superabsorbent polymer composition. Table 1 shows the results.

Example 5 1210 g of cyclohexane was placed in a 5000 ml four-necked round-bottom flask equipped with a stirrer, reflux condenser, temperature tube and nitrogen gas inlet tube, and sorbitan monostearate 9 was added.
After adding g to dissolve, nitrogen gas was blown in to expel dissolved oxygen. Separately, 350 g of acrylic acid was dissolved in 727.7 g of water while externally cooling 350 g of acrylic acid in a beaker having a capacity of 2000 ml.
Was added to neutralize 70% of the carboxyl groups. Next, 0.37 g of N, N'-methylenebisacrylamide and 0.94 g of potassium persulfate were added and dissolved, and then dissolved oxygen was expelled by blowing nitrogen gas. The contents of the beaker having a capacity of 2000 ml were added to the contents of the four-necked round bottom flask, dispersed by stirring, and the inside temperature of the flask was raised by an oil bath while bubbling nitrogen gas. When the temperature reached around ℃, the internal temperature rose sharply, and reached several minutes after reaching 75 ° C.
Then, the mixture was reacted for 3 hours while stirring. Further, in this flask, di (alkylaminoethyl) glycine hydrochloride Levon 50 (manufactured by Sanyo Chemical Industries, Ltd., component concentration: 50)
%, And an alkyl group containing 8 g of C ₈ H ₁₇ ) dissolved in 400 g of water was added dropwise over 15 minutes, and held for 30 minutes to uniformly absorb the aqueous solution with the superabsorbent polymer. Thereafter, the polymer was removed by decantation, transferred to a reduced-pressure drier, and the attached cyclohexane and water were removed at 90 ° C. to obtain a desired powdery superabsorbent polymer composition. The above measurement was performed on the obtained superabsorbent polymer composition. Table 1 shows the results.

Example 6 A 1 l stainless steel separable flask was charged with 80 g of sodium acrylate, 20 g of acrylic acid, 0.1 g of N, N'-methylenebisacrylamide and 400 g of water, and the flask was externally heated with stirring. This kept the temperature of the contents at 40 ° C. After purging the system with nitrogen,
0.1 g of 2,2'-azobis (2-amidinopropane) hydrochloride was added and mixed, and polymerization was carried out for 1 hour. Thereafter, the hydrogel polymer was taken out of the flask,
The drying was carried out by a drier which was heated for 1 hour. The obtained dried product was pulverized using a household mixer to obtain a superabsorbent polymer. 100 g of the superabsorbent polymer was obtained in the same manner as in Example 1,
In a double-arm kneader, while stirring, di (alkylaminoethyl) glycine hydrochloride Levon 50 (manufactured by Sanyo Chemical Industries, Ltd., component concentration: 50%, alkyl group is C
After spraying an aqueous solution in which 2 g of ₈ H ₁₇ ) was dissolved in 100 g of water, the solution was held for 15 minutes and uniformly absorbed by the superabsorbent polymer. Thereafter, the polymer was taken out, transferred to a vacuum dryer again, and dried at 90 ° C. to obtain a powdery superabsorbent polymer composition. The above measurement was performed on the obtained superabsorbent polymer composition. Table 1 shows the results.

Comparative Example 1 A glycine-type zwitterionic surfactant was added to a monomer before polymerization. 1210 g of cyclohexane was placed in a 5000 ml four-necked round bottom flask equipped with a stirrer, a reflux condenser, a temperature tube, and a nitrogen gas inlet tube, and 9 g of sorbitan monostearate was added and dissolved, and then nitrogen gas was blown. , Expelled dissolved oxygen. Separately, capacity 2000
143.1 g of 350 g of acrylic acid dissolved in 727.7 g of water while cooling from the outside in a beaker of 350 ml
Was added to neutralize 70% of the carboxyl groups. Next, 0.37 g of N, N'-methylenebisacrylamide, 0.94 g of potassium persulfate, and Levon 50 (manufactured by Sanyo Chemical Industries, Ltd., di (alkylaminoethyl) glycine hydrochloride, component concentration: 50% After dissolving the alkyl group by adding 8 g of C ₈ H ₁₇ ), dissolved oxygen was expelled by blowing nitrogen gas. The contents of the four-necked round bottom flask are
The contents of the beaker (00 ml) were added, and the mixture was stirred and dispersed. The internal temperature of the flask was increased by an oil bath while bubbling nitrogen gas. At around 60 ° C., the polymer was wound around the stirrer, causing a dangerous state, and the polymerization was stopped.

Comparative Example 2 A superabsorbent polymer composition was prepared in the same manner as in Example 1 except that di (alkylaminoethyl) glycine hydrochloride was not added. The above measurement was performed on the obtained superabsorbent polymer composition. Table 1 shows the results.

Comparative Example 3 A superabsorbent polymer composition was prepared in the same manner as in Example 5 except that di (alkylaminoethyl) glycine hydrochloride was not added. The above measurement was performed on the obtained superabsorbent polymer composition. Table 1 shows the results.

Comparative Example 4 An experiment was conducted in accordance with the method described in JP-A-8-332379. The di (alkylaminoethyl) glycine hydrochloride of Example 1 was treated with sodium tetraborate anhydride (Na ₂ B ₄
O ₇ , manufactured by Wako Pure Chemical Industries, Ltd., high quality water absorbent obtained by mixing in the same manner as in Example 1 except that the amount added was changed from 4 g to 0.2 g. The above measurements were made on the polymer composition. Table 1 shows the measurement results.

Comparative Example 5 An experiment was conducted in accordance with the method described in JP-A-4-17058. Example 1 Except that di (alkylaminoethyl) glycine hydrochloride of Example 1 was changed to a benzalkonium chloride solution (10% aqueous solution manufactured by Wako Pure Chemical Industries, Ltd.), and the addition amount was changed from 0.2 g to 10 g. The above measurement was performed on the superabsorbent polymer composition obtained by mixing in the same manner as in Example 1. Table 1 shows the measurement results.

[0044]

The superabsorbent polymer composition according to the present invention exhibits an excellent deodorizing effect on urine / human waste without impairing the original water absorbing performance of the superabsorbent polymer. Therefore,
The superabsorbent polymer composition of the present invention can be particularly preferably used in the field of sanitary materials such as disposable diapers, sanitary napkins and various pads.

[0045]

[Table 1]

Claims (4)

[Claims] 1. A glycine-type amphoteric surfactant (100 parts) is added to 100 parts of a superabsorbent polymer (A) obtained by polymerizing a water-soluble polymerizable monomer in the presence of a cross-linking agent at an optional stage after completion of the polymerization. B) A method for producing a superabsorbent polymer, comprising adding 0.01 to 5 parts of B). 2. The method of claim 1, wherein the water-soluble polymerizable monomer comprises at least 50
The production method according to claim 1, wherein the weight% is acrylic acid and an alkali metal salt thereof. 3. A glycine-type zwitterionic surfactant (B)
Is at least one selected from the group consisting of alkyl di (aminoethyl) glycine hydrochloride, alkyl di (aminoethyl) glycine sodium salt and alkyl polyalkylethyl glycine hydrochloride. 4. A glycine-type zwitterionic surfactant (B)
Is at least one selected from alkyldi (aminoethyl) glycine hydrochloride, alkyldi (aminoethyl) glycine sodium salt and alkylpolyalkylethylglycine hydrochloride, and the alkyl group has 8 to 18 carbon atoms. 4. The production method according to any one of 1 to 3.