KR102242700B1 - Super absorbent polymer and method for preparing the same - Google Patents

Abstract

A superabsorbent polymer with minimal aggregation and a method for manufacturing the same are provided. The method for preparing the super absorbent polymer comprises the steps of surface crosslinking a hydrogel crosslinked polymer having an internal crosslinking structure, and contacting the hydrogel crosslinked polymer subjected to surface crosslinking with a post-treatment solution containing a substance having a hydroxyl group. Includes steps.

Description

Super absorbent polymer and its manufacturing method TECHNICAL FIELD [SUPER ABSORBENT POLYMER AND METHOD FOR PREPARING THE SAME}

The present invention relates to a super absorbent polymer and a method for producing a super absorbent polymer.

Super Absorbent Polymer (SAP) is a synthetic polymer material that has a function of absorbing moisture from 500 to 1,000 times its own weight, and each developer has a SAM (Super Absorbency Material), AGM (Absorbent Gel Material). ) And so on. Since the above superabsorbent resin has begun to be put into practical use as a sanitary tool, nowadays, in addition to hygiene products such as paper diapers for children, soil repair agents for horticulture, water resistant materials for civil engineering and construction, sheets for seedlings, freshness maintenance agents in the food distribution field, and poultices. It is widely used as a material for goods and the like.

As a method of preparing the super absorbent polymer as described above, a method by reverse phase suspension polymerization or a method by aqueous solution polymerization is known. Regarding the reverse phase suspension polymerization, for example, Japanese Patent Publication No. 56-161408, Japanese Patent Publication No. 57-158209, and Japanese Patent Publication No. 57-198714 are disclosed. As a method of aqueous solution polymerization, a thermal polymerization method in which heat is applied to the aqueous solution to polymerize, and a photopolymerization method in which polymerization is performed by irradiation with ultraviolet rays or the like are known.

On the other hand, as the uses of super absorbent polymers diversify, absorption ratio, centrifuge retention capacity (CRC), absorption under pressure (AUP), absorption rate (Free Swelling Rate, FSR), and liquid permeability (Gel) Bed Permeability, GBP), antibacterial properties, filling properties, etc. are required. In order to improve these properties, a post-treatment process may be performed after forming the polymer. However, during the post-treatment process, the superabsorbent polymer may aggregate and the coarse powder content may increase.

Accordingly, the problem to be solved by the present invention is to provide a method of manufacturing a super absorbent polymer with minimized aggregation.

Another problem to be solved by the present invention is to provide a super absorbent polymer having a small coarse content and a uniform powder particle size.

The problems of the present invention are not limited to the technical problems mentioned above, and other technical problems that are not mentioned will be clearly understood by those skilled in the art from the following description.

The method for producing a super absorbent polymer according to an embodiment of the present invention for solving the above problems includes the steps of surface crosslinking a hydrogel crosslinked polymer having an internal crosslinking structure, and the hydrogel crosslinked polymer subjected to the surface crosslinking treatment. And contacting with a post-treatment solution containing a substance having a hydroxyl group.

The step of contacting the hydrogel crosslinked polymer with the post-treatment solution includes contacting the hydrogel crosslinked polymer with 0.05 parts by weight or more and less than 1 part by weight of the material having a hydroxyl group based on 100 parts by weight of the hydrogel crosslinked polymer. It may include a step of.

Here, the material having a hydroxyl group may include at least one selected from the group of polyhydric alcohols consisting of ethylene glycol, triethylene glycol, 1,3-propanediol, and 1,4-butanediol.

In addition, the material having a hydroxyl group may include at least one selected from the group of polyols consisting of polyethylene glycol, trimethylolpropane ethoxylate, and polyvinyl alcohol.

The step of surface crosslinking the hydrogel crosslinked polymer, the hydrogel crosslinked polymer, an alkyl diol, an alkylene glycol, an alkyl diglycidyl ether, an alkylene glycol diglycidyl ether, an alkylene carbonate, and a polyhydric It may include contacting with a surface crosslinking agent containing at least one selected from the group containing metals.

Here, the step of surface crosslinking the hydrogel crosslinked polymer may further include heat treating the hydrogel crosslinked polymer after contacting the hydrogel crosslinked polymer with the surface crosslinking agent.

Here, the step of surface crosslinking the hydrogel crosslinked polymer may further include contacting the hydrogel crosslinked polymer with a silica-based compound before contacting the hydrogel crosslinked polymer with the surface crosslinking agent.

In addition, the post-treatment solution further comprises a cationic polymer, wherein the step of contacting the hydrogel crosslinked polymer with the posttreatment solution includes the hydrogel crosslinked polymer, the cation based on 100 parts by weight of the hydrogel crosslinked polymer. It may include the step of contacting with 0.1 to 2 parts by weight of the polymer.

In addition, before the step of surface crosslinking the hydrogel crosslinked polymer, preparing a hydrogel crosslinked polymer having the inner crosslinking structure by polymerizing a monomer composition comprising a hydrophilic monomer and an inner crosslinking agent, cutting the hydrogel crosslinked polymer The step of, drying the cut hydrogel crosslinked polymer, and pulverizing the dried hydrogel crosslinked polymer may be further included.

Further, the method for preparing the super absorbent polymer may include a heat treatment process after the step of contacting the hydrogel crosslinked polymer with the post-treatment solution.

The super absorbent polymer according to an embodiment of the present invention for solving the above other problems is manufactured according to the above-described manufacturing method.

The super absorbent polymer is in the form of a powder, and particles having a particle size of 850 µm or more may be 1% or less of the total particles.

Details of other embodiments are included in the detailed description and drawings.

According to the method of manufacturing a super absorbent polymer according to an embodiment of the present invention, a super absorbent polymer having improved properties such as absorption ratio, absorption rate, water holding capacity, absorption capacity under pressure, and liquid permeability through a post-treatment process can be prepared. .

In addition, by adding a substance having a hydroxyl group to the post-treatment solution, an additional drying process can be omitted because a superabsorbent polymer having minimal aggregation can be prepared without going through a separate additional drying process after the post-treatment process. Through this, it is possible to prevent occurrence of deterioration in properties of the super absorbent polymer during the additional drying process.

Effects according to the embodiments of the present invention are not limited by the contents exemplified above, and more various effects are included in the present specification.

1 is a flow chart showing a method of manufacturing a super absorbent polymer according to an embodiment of the present invention.
Figure 2 is a result of comparing the particle size of the resin according to the experimental example.
3 is a photograph of a resin of Preparation Example 1, Preparation Example 2, and Comparative Example 1. FIG.

Advantages and features of the present invention, and a method of achieving them will become apparent with reference to the embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in a variety of different forms, and only the embodiments make the disclosure of the present invention complete, and those skilled in the art to which the present invention pertains. It is provided to fully inform the person of the scope of the invention, and the invention is only defined by the scope of the claims.

In this specification, "C _AB " indicates that the number of carbon atoms is A or more and B or less. For example, a C _1-5 alkyl group means an alkyl group having 1 to 5 carbon atoms. "And/or" includes each and every combination of one or more of the recited items. Numerical ranges indicated using "to" represent numerical ranges including the values listed before and after the lower limit and upper limit, respectively, unless otherwise stated. The same reference numerals refer to the same elements throughout the specification.

Although the first, second, and the like are used to describe various components, it goes without saying that these components are not limited by these terms. These terms are only used to distinguish one component from another component.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

1 is a flow chart showing a method of manufacturing a super absorbent polymer according to an embodiment of the present invention.

Referring to FIG. 1, a method of preparing a super absorbent polymer according to an embodiment of the present invention includes preparing a crosslinked polymer of a monomer composition including a hydrophilic monomer, a crosslinking agent, and a polymerization initiator (S110), and cutting the crosslinked polymer. (S120), drying the crosslinked polymer (S130), pulverizing the crosslinked polymer (S140), surface crosslinking the crosslinked polymer (S150), and post-treating the crosslinked polymer (S160). I can.

Preparing a crosslinked polymer of a monomer composition comprising a hydrophilic monomer, a crosslinking agent and a polymerization initiator (S110) comprises preparing a monomer composition comprising a hydrophilic monomer, a crosslinking agent and a polymerization initiator (S111), and polymerizing the monomer composition It may include (S112).

First, a monomer composition containing a hydrophilic monomer, a crosslinking agent, and a polymerization initiator is prepared (S111).

The hydrophilic monomer may be a monomer including a hydrophilic group, such as a hydroxyl group (-OH), a carboxyl group (-COOH), an amide group (-NH ₂ ), and the like. The hydrophilic monomer is not limited as long as it is generally used in the manufacture of a super absorbent polymer, but may be, for example, a water-soluble ethylenically unsaturated monomer. The water-soluble ethylenically unsaturated monomer may be an anionic monomer and a salt thereof, a nonionic hydrophilic-containing monomer, an amino group-containing unsaturated monomer, a quaternary product thereof, or a mixture thereof.

Examples of the anionic monomer and its salt include acrylic acid, methacrylic acid, maleic anhydride, fumaric acid, crotonic acid, itaconic acid, 2-acryloylethane sulfonic acid, 2-methacryloylethanesulfonic acid, and 2-(meth)acrylic. Roylpropanesulfonic acid and 2-(meth)acrylamide-2-methylpropanesulfonic acid.

In addition, examples of the nonionic hydrophilic-containing monomer include (meth)acrylamide, N-substituted (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, Methoxy polyethylene glycol (meth) acrylate, polyethylene glycol (meth) acrylate, and the like.

Further, examples of the amino group-containing unsaturated monomer and its quaternary product include (N,N)-dimethylaminoethyl (meth)acrylate and (N,N)-dimethylaminopropyl (meth)acrylamide. .

The concentration of the water-soluble ethylenically unsaturated monomer in the monomer composition may be appropriately selected in consideration of the type of the reactor and polymerization conditions, but may be, for example, in the range of 30% by weight or more and 60% by weight or less.

The crosslinking agent includes an atomic group capable of reacting with a functional group of the hydrophilic monomer and at least one ethylenically unsaturated group, or two atomic groups capable of reacting with a functional group of the hydrophilic monomer and a functional group formed by hydrolysis of the hydrophilic monomer. The compounds contained above can be used. The crosslinking agent may be included in a range of about 0.01 parts by weight to about 0.5 parts by weight based on 100 parts by weight of the hydrophilic monomer.

The crosslinking agent is bisacrylamide C _8-12, C _8-12 bismethacrylate acrylamide, C _2-12 poly (meth) poly (meth) allyl ether, or mixtures thereof acrylates, C _2-10 polyols of the polyol It can be any one of.

Specifically, examples of the crosslinking agent include (poly) ethylene glycol (meth) acrylate, (poly) propylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, ethoxyl (3)-trimethylol Propanetri(meth)acrylate, ethoxyl(6)-trimethylolpropanetri(meth)acrylate, ethoxyl(9)-trimethylolpropanetri(meth)acrylate, ethoxyl(15)-trimethylolpropanetri (Meth)acrylate glycerin tri(meth)acrylate, glycerin acrylate methacrylate, 2,2-bis[(acryloxy)methyl]butyl acrylate (3EO), N,N'-methylenebis(meth)acrylic Rate, ethyleneoxy(meth)acrylate, polyethyleneoxy(meth)acrylate, propyleneoxy(meth)acrylate, glycerin, glycerin diacrylate, glycerin triacrylate, trimethylol triacrylate, triallylamine, tri Aryl cyanurate, triallyl isocyanate, pentaethyleneimine, ethylene glycol, polyethylene glycol diethylene glycol, polyethylene glycol diacrylate, polymethylolpropane triacrylate or propylene glycol, but are not limited thereto. .

The polymerization initiator may include at least one of a photo polymerization initiator, a thermal polymerization initiator, and an oxidation-reduction polymerization initiator. For example, the monomer composition may contain a photopolymerization initiator and a thermal polymerization initiator together as a polymerization initiator.

As the photopolymerization initiator, diethoxy acetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 4-(2-hydroxy ethoxy)phenyl-(2-hydroxy)-2- Acetophenone derivatives such as propyl ketone and 1-hydroxycyclohexylphenyl ketone; Benzoin alkyl ether compounds such as benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and benzoin isobutyl ether; benzophenone derivatives such as o-benzoyl methyl benzoate, 4-phenyl benzophenone, 4-benzoyl-4'-methyl-diphenyl sulfide, and (4-benzoyl benzyl) trimethyl ammonium chloride; Thioxanthone-based compounds; Bis(2,4,6-trimethylbenzoyl)-phenyl phosphine oxide, diphenyl(2,4,6-trimethylbenzoyl)-phosphine oxide, diphenyl (2,4,5-trimethylbenzoyl)-phosphine oxide Acyl phosphine oxide derivatives such as seeds; Or 2-hydroxy methyl propionitrile, 2,2'-(azobis(2-methyl-N-(1,1'-bis(hydroxymethyl)-2-hydroxyethyl)propion amide) Compound; azo initiator; peroxide initiator; redox initiator; organic halide initiator; sodium persulfate (Na2S2O8); potassium persulfate (K2S2O8); or a mixture thereof The thermal polymerization initiator may be used by mixing one or two or more of an azo-based initiator, a peroxide-based initiator, a redox-based initiator, or an organic halide initiator. .

The content of the polymerization initiator in the monomer composition may be appropriately selected so as to exhibit a polymerization initiation effect. For example, the photopolymerization initiator is included in the range of about 0.005 to 0.1 parts by weight based on 100 parts by weight of the hydrophilic monomer, and the thermal polymerization initiator is included in the range of about 0.01 to 0.5 parts by weight based on 100 parts by weight of the hydrophilic monomer. Can be included.

Then, the monomer composition is polymerized (S112). In an exemplary embodiment, the step of polymerizing the monomer composition (S112) may be a step of forming a sheet-like hydrogel crosslinked polymer by irradiating light to the monomer composition. The light may be irradiated using a light source such as an Xe lamp, a mercury lamp, or a metal halide lamp, but is not limited thereto. In addition, the light may be ultraviolet rays having a wavelength in the range of about 200 nm to 400 nm. The exposure amount and irradiation time of the light can be appropriately selected in consideration of reaction conditions. For example, the light may be irradiated for a time in the range of about 10 seconds to 5 minutes, or about 20 seconds to 3 minutes at an exposure amount in the range of ^{about 0.5 mW/cm 2} to 500 mW/cm ^2. An effective photopolymerization reaction may occur within the wavelength, exposure amount, and irradiation time range, and it is possible to prevent the crosslinking point of the polymer from being cut due to excessive light irradiation.

In another embodiment, the step of polymerizing the monomer composition may be a step of thermally polymerizing the monomer composition or oxidation-reduction polymerization.

Next, the sheet-shaped crosslinked polymer is cut (S120). The step of cutting the crosslinked polymer (S120) may be performed more than once. By preparing the polymerized sheet-like crosslinked polymer into a particulate crosslinked polymer through one or more cutting processes, it is possible to improve processability in subsequent subsequent processes and to produce a super absorbent polymer that is easy to handle. In an exemplary embodiment, the step of cutting the crosslinked polymer (S120) comprises the steps of first cutting the crosslinked polymer using a first cutter (S121) and the crosslinked polymer using a second cutter different from the first cutter. It may include the step of cutting the tea (S122).

The step of first cutting the crosslinked polymer (S121) may be a step of pre-cutting a particulate crosslinked polymer having a first average size by transferring the obtained sheet-shaped crosslinked polymer to a cutter after the polymerization reaction is completed. For example, the pre-cut particulate crosslinked polymer may have a random size, or an average size of about 2 cm x 2 cm to about 4 cm x 4 cm, or an average size of about 3 cm x 3 cm. The step of first cutting the crosslinked polymer (S121) may be performed using a kneader-type cutter or a cutter-type cutter, but is not limited thereto.

The step of secondary cutting the crosslinked polymer (S122) may be a step of chopping the pre-cut particulate crosslinked polymer with a particulate crosslinked polymer having a second average size smaller than the first average size. For example, the chopped particulate crosslinked polymer may have an average size of about 0.2 cm x 0.2 cm to about 1 cm x 1 cm, or about 0.5 cm x 0.5 cm. The second cutting of the crosslinked polymer (S122) may be performed using a chopper type cutter, but is not limited thereto.

Next, the crosslinked polymer is dried (S130). The step of drying the crosslinked polymer (S130) may be a step of heating the crosslinked polymer to consume an unreacted residual monomer while drying the residual solvent of the polymer. The heating may be performed using a hot air dryer, a fluid bed dryer, an air flow dryer, an infrared dryer, or a dielectric heating dryer, but is not limited thereto. In addition, the drying is performed at a temperature in the range of about 100°C to 200°C, or about 150°C to 180°C for a time in the range of about 20 minutes to 80 minutes, or about 30 minutes to 70 minutes, or about 40 minutes to 60 minutes. Can be. In the above temperature and drying time range, deterioration of the crosslinked polymer is prevented and efficient drying is possible.

Next, the crosslinked polymer is pulverized (S140). The step of pulverizing the crosslinked polymer is a step of pulverizing or pulverizing the particulate crosslinked polymer to a predetermined size to prepare a powdery crosslinked polymer, and the step of pulverizing the crosslinked polymer includes a vibration type pulverizer, an impact type pulverizer, a friction type pulverizer, or a pin mill pulverizer. It may be performed using, but is not limited thereto. In some embodiments, after the step of pulverizing the crosslinked polymer, the step of drying the pulverized crosslinked polymer again may be further included, and the step of pulverizing the crosslinked polymer and the step of drying the crosslinked polymer are alternately performed a plurality of times. It could be.

Next, the crosslinked polymer is subjected to a surface crosslinking treatment (S150). In this specification, the surface crosslinking treatment means a surface modification treatment that increases the crosslinking density near the surface of the particle. In an exemplary embodiment, the step of surface crosslinking treatment of the crosslinked polymer (S150) includes mixing the crosslinked polymer with a silica material (S151), mixing the silica-treated crosslinked polymer with a surface crosslinking agent (S152), and a surface crosslinking agent. It may include the step of heat-treating the crosslinked polymer mixed with (S153).

The step of mixing the crosslinked polymer with the silica material (S151) may be a step of treating the surface of the crosslinked polymer with silica by using a mixer, for example, a powder mixer, to contact the crosslinked polymer with the silica material. The silica material may be mixed in an amount of about 0.1 to 3 parts by weight, or about 0.5 parts by weight based on 100 parts by weight of the crosslinked polymer. By performing silica treatment on the surface of the crosslinked polymer, agglomeration between the superabsorbent polymers may be reduced in the step of mixing with a surface crosslinking agent to be described later (S152), and the liquid permeability of the superabsorbent polymer may be improved.

The step of mixing the silica-treated crosslinked polymer with the surface crosslinking agent (S152) may be a step of contacting the crosslinked polymer with the surface crosslinking agent using a mixer, for example, a surface crosslinking mixer. The surface crosslinking agent is not particularly limited as long as it is a material capable of modifying the surface of the crosslinked polymer through a solvent. For example, a surface crosslinking component such as a condensation reactive surface crosslinking material, an ionic surface crosslinking material, or a mixture thereof, and water And/or a solvent such as ethanol.

Examples of the condensation-reactive surface crosslinking material include polyhydric alcohol compounds such as alkyl diols, alkylene glycols, alkyl diglycidyl ethers, alkylene glycol diglycidyl ethers, alkylene carbonate compounds, epoxy compounds, and polyamine compounds. , A haloepoxy compound, an oxazoline compound, or a mixture thereof, and examples of the ionic surface crosslinking material include a polyvalent metal salt. In an exemplary embodiment, the surface crosslinking agent may include ethylene carbonate, aluminum sulfate, and water.

The step of heat-treating the crosslinked polymer mixed with the surface crosslinking agent (S153) may be a step of heating the crosslinked polymer to accelerate the reaction between the surface crosslinking agent and the crosslinked polymer. The heating may be performed using a hot air dryer, a fluid bed dryer, an air flow dryer, an infrared dryer, or a dielectric heating dryer, but is not limited thereto. In addition, the step of heat-treating the crosslinked polymer mixed with the surface crosslinking agent (S153) may be performed for a shorter time than the step of drying the crosslinked polymer (S130). For example, the drying may be performed at a temperature ranging from about 100° C. to 200° C., or from about 150° C. to 180° C. for a time ranging from about 20 minutes to 80 minutes, or from about 25 minutes to 70 minutes, or from about 30 minutes to 60 minutes. Can be performed during.

The surface crosslinking agent may react with the non-crosslinked linear polymer chain to lower the water-soluble component and residual monomer content of the super absorbent polymer. In addition, the water holding capacity of the super absorbent polymer may be improved due to the hydrophilic alkylene oxy group.

Next, the crosslinked polymer is post-treated (S160). In the present specification, post-treatment refers to a treatment performed after crosslinking the inside and the surface of the hydrogel. The post-treatment step S160 may be a step of performing a treatment for improving properties of the super absorbent polymer, such as liquid permeability and absorption rate, and alleviating aggregation. The post-treatment step (S160) includes contacting the crosslinked polymer with the post-treatment solution.

In an exemplary embodiment, the post-treatment solution may be an aqueous solution containing water and a substance having a hydroxyl group. By post-treating the surface of the crosslinked polymer with a post-treatment solution containing a substance having a hydroxyl group, aggregation of the crosslinked polymer powder can be suppressed. In particular, even though the post-treatment solution is an aqueous solution, the agglomeration of the crosslinked polymer is minimized without an additional heat treatment process (e.g., a drying process), so that particles having a particle size of 850 μm or more are 1% or less of the total particles. It can be manufactured, and thus the amount of super absorbent polymer lost in the classification process can be reduced. Furthermore, there is an effect of preventing the deterioration of the properties of the super absorbent polymer that may occur during the additional heat treatment process by not including the additional heat treatment process after the post treatment process.

The substance having a hydroxyl group is ethylene glycol, triethylene glycol, 1,3-propanediol, or 1,4-butanediol Polyols such as low molecular weight compounds, or polyols such as polyethylene glycol, trimethylolpropane ethoxylate, or polyvinyl alcohol may be exemplified. . The material having a hydroxyl group may be in contact with about 0.05 or more and less than 1 part by weight based on 100 parts by weight of the crosslinked polymer. Aggregation can be suppressed when the material having a hydroxyl group is in contact with 0.05 parts by weight or more, and when the material having a hydroxyl group is in contact with less than 1 part by weight, the post-treatment solution is excessively added to cause reaggregation. There is an effect that can prevent it.

In another embodiment, the post-treatment solution may further include a cationic polymer. By post-treating the surface of the crosslinked polymer with a post-treatment solution containing a cationic polymer, it is possible to improve the liquid permeability of the super absorbent polymer. The cationic polymer may contact about 0.1 to 2 parts by weight based on 100 parts by weight of the crosslinked polymer.

Hereinafter, a method of manufacturing a super absorbent polymer according to the present invention will be described in more detail with reference to Preparation Examples, Comparative Examples and Experimental Examples.

< Manufacturing example 1>

After mixing 77.778 g of 50% caustic soda solution (NaOH) and 88.84 g of water, 100 g of acrylic acid, 0.050 g of polyethylene glycol diacrylate (Mw=400) as an internal crosslinking agent, 2,2-bis[(acryloxy)methyl]butyl A monomer aqueous solution having a monomer concentration of 45% by weight was prepared by mixing 0.050 g of acrylate (15E0) and 0.033 g of diphenyl (2,4,6-trimethylbenzoyl)-phosphine oxide as a photopolymerization initiator. Then, 1.33 g of potassium persulfate as a thermal initiator was dissolved in 8.67 g of water, and 3.008 g was mixed with the aqueous monomer solution to prepare a monomer composition. Thereafter, the monomer composition is introduced through the supply unit of a polymerization reactor consisting of a conveyor belt continuously moving at 40°C, and then ^{irradiated with an irradiation amount of 9} mW/cm 2 through a UV irradiation device, and photopolymerization is performed for 3 minutes. A phase hydrogel polymer was prepared. The hydrogel polymer was transferred to a cutter and cut into 2 cm. At this time, the water content of the cut hydrogel polymer was 50% by weight. The cut hydrogel polymer was chopped using a meat chopper. Subsequently, the hydrogel polymer was dried for 1 hour in a hot air dryer at 180°C, and the dried hydrogel polymer was pulverized with a pin mill. Thereafter, the polymer powder was classified by a standard mesh of ASTM standard to obtain a powder having an average particle diameter of 150 to 850 μm. After 0.5 g of silica was added to the obtained powder and mixed, a surface crosslinking solution containing 0.5 g of ethylene carbonate, 1 g of aluminum sulfate, and 5 g of water (DW) was added, and reacted in a hot air dryer at 180° C. for 30 minutes. The dried powder was once again classified to obtain a powdery resin having an average particle size of 150 to 850 μm. Thereafter, a post-treatment solution containing 3 g of water (DW), 1 g of cationic polymer, and 0.5 g of triethylene glycol was mixed with 100 g of the obtained resin to obtain a water absorbent resin in powder form.

< Manufacturing example 2>

A hydrogel crosslinked polymer was prepared in the same manner as in Preparation Example 1, except that the hydrogel crosslinked polymer was treated using a post-treatment solution containing 0.5g of trimethylolpropane ethoxylate instead of 0.5g of triethylene glycol. A water absorbent resin was obtained by crosslinking treatment and post treatment.

< Comparative example 1>

A hydrogel crosslinked polymer was prepared in the same manner as in Preparation Example 1, except that the hydrogel crosslinked polymer was treated using a post-treatment solution not containing triethylene glycol, and a water absorbent resin was obtained by surface crosslinking treatment and post-treatment. I did.

< Comparative example 2>

A hydrogel crosslinked polymer was prepared in the same manner as in Preparation Example 1, except that the hydrogel crosslinked polymer was treated using a post-treatment solution containing 1 g of trimethylolpropane ethoxylate instead of 0.5 g of triethylene glycol, and the surface crosslinked Treatment and post-treatment were performed to obtain a water absorbent resin.

< Experimental example >

The particle size sizes of the water absorbent resins prepared and obtained according to Preparation Example 1, Preparation Example 2, Comparative Example 1, and Comparative Example 2 were measured, and the results are shown in Tables 1 and 2 below.

>850㎛ (%) 850-600㎛ (%) 600-300㎛ (%) 300-150㎛ (%) Manufacturing Example 1 0.6 38 55.5 6.3 Manufacturing Example 2 0.9 29.2 65.4 5.7 Comparative Example 1 13.4 36.4 48.4 2.2 Comparative Example 2 7.8 36.6 52.8 3.3

Figure 2 is a result of comparing the particle size of the resin according to the experimental example. 3 is a photograph of a resin of Preparation Example 1, Preparation Example 2, and Comparative Example 1. FIG.

Referring to Table 1 and FIG. 2, post-treatment using the water absorbent resin of Preparation Example 1 and 0.5 parts by weight of trimethylolpropane ethoxylate, which was post-treated with 0.5 parts by weight of triethylene glycol with respect to 100 parts by weight of the resin in powder form. In the case of the water absorbent resin of Preparation Example 2, it can be seen that particles having a particle size of 850 μm or more are 1% or less of the total particles.

In the case of the water absorbent resin of Comparative Example 1 not post-treated using triethylene glycol and trimethylolpropane ethoxylate, it can be seen that the particles having a particle size of 850 μm or more are 13.4% of the total particles. In the case of the water absorbent resin of Comparative Example 2, which was post-treated with 1 part by weight of trimethylolpropane ethoxylate based on 100 parts by weight of the resin in powder form, the amount of coarse content was reduced compared to Comparative Example 1, but particles having a particle size of 850 μm or more It can be seen that it is 7.8% of the total particles.

Referring to FIG. 3, in the case of the resin powder of Preparation Example 1 (Ref.+TEG) and the resin powder of Preparation Example 2 (Ref.+polyol), the coarse powder content was smaller than that of the resin powder of Comparative Example 1 (Ref.), and thus particles. It can be confirmed with the naked eye that the size is fine and uniform.

The embodiments of the present invention have been described above, but these are only examples and do not limit the present invention, and those of ordinary skill in the field to which the present invention pertains, within the scope not departing from the essential characteristics of the embodiments of the present invention. It will be appreciated that various modifications and applications not illustrated above are possible. For example, each component specifically shown in the embodiment of the present invention can be modified and implemented. And differences related to these modifications and applications should be construed as being included in the scope of the present invention defined in the appended claims.

Claims (12)

Preparing a hydrogel-like crosslinked polymer having an internal crosslinked structure;
Subjecting the hydrogel crosslinked polymer to a surface crosslinking treatment; And
After the step of crosslinking the surface, contacting the hydrogel crosslinked polymer subjected to surface crosslinking with a post-treatment solution containing a material having a hydroxyl group,
The step of contacting the hydrogel crosslinked polymer with the post-treatment solution,
Of a super absorbent polymer comprising the step of contacting the hydrogel crosslinked polymer with the post-treatment solution containing a material having a hydroxyl group of 0.05 parts by weight or more and less than 1 part by weight of the hydrogel crosslinked polymer Manufacturing method. delete The method of claim 1,
The material having a hydroxyl group is a method of producing a super absorbent polymer comprising at least one selected from the group of polyhydric alcohols consisting of ethylene glycol, triethylene glycol, 1,3-propanediol, and 1,4-butanediol. The method of claim 1,
The material having a hydroxyl group is a method for producing a super absorbent polymer comprising at least one selected from the group of polyols consisting of polyethylene glycol, trimethylolpropane ethoxylate, and polyvinyl alcohol. The method of claim 1,
The step of surface crosslinking the hydrogel crosslinked polymer,
Surface comprising the hydrogel crosslinked polymer, at least one selected from the group containing alkyl diols, alkylene glycols, alkyl diglycidyl ethers, alkylene glycol diglycidyl ethers, alkylene carbonates, and polyvalent metals A method for producing a super absorbent polymer comprising the step of contacting with a crosslinking agent. The method of claim 5,
The step of surface crosslinking the hydrogel crosslinked polymer,
After the step of contacting the hydrogel crosslinked polymer with the surface crosslinking agent, the method of manufacturing a super absorbent polymer further comprising heat-treating the hydrogel crosslinked polymer. The method of claim 6,
The step of surface crosslinking the hydrogel crosslinked polymer,
Before the step of contacting the hydrogel crosslinked polymer with the surface crosslinking agent, the method of manufacturing a super absorbent polymer further comprising contacting the hydrogel crosslinked polymer with a silica-based compound. The method of claim 5,
The post-treatment solution further comprises a cationic polymer,
The step of contacting the hydrogel crosslinked polymer with the post-treatment solution,
A method for producing a super absorbent polymer comprising contacting the hydrogel crosslinked polymer with 0.1 to 2 parts by weight of the cationic polymer with respect to 100 parts by weight of the hydrogel crosslinked polymer. The method of claim 5,
The step of preparing a hydrogel-like crosslinked polymer having an internal crosslinked structure,
Polymerizing a monomer composition comprising a hydrophilic monomer and an internal crosslinking agent to prepare a hydrogel-like crosslinked polymer having the internal crosslinking structure;
Cutting the hydrogel crosslinked polymer;
Drying the cut hydrogel crosslinked polymer; And
A method for producing a super absorbent polymer comprising the step of pulverizing the dried hydrogel crosslinked polymer. The method of claim 9,
After the step of contacting the hydrogel crosslinked polymer with the post-treatment solution, a method for producing a super absorbent polymer comprising no heat treatment process. As a super absorbent polymer prepared by the method according to any one of claims 1 and 3 to 10,
The super absorbent polymer is in the form of a powder,
Particles with a particle size of 150 μm or more and 300 μm or less are 5% or more and 7% or less of the total particles,
Particles with a particle size of 300 μm or more and 600 μm or less are 55% or more and 67% or less of the total particles,
Particles with a particle size of 600㎛ or more and 850㎛ or less are 27% or more and 39% or less of the total particles,
A super absorbent polymer in which particles having a particle size of 850 μm or more are 0.1% or more and 1% or less of the total particles. delete

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