KR101700354B1 - Analytical Method for CRC of Super Absorbent Polymer Resin and Analytical System Using the Same - Google Patents

Abstract

The invention then swell the superabsorbent polymer (a) in D ₂ O and measuring the relaxation time T2; And (b) calculating a CRC value using the T2 relaxation time value in the step (a), and to an analysis system using the CRC measurement method.

Description

Technical Field [0001] The present invention relates to a method of measuring CRC of a superabsorbent resin and an analytical system using the same,

The present invention relates to a method for measuring CRC of a superabsorbent resin and an analysis system using the same.

It is expected to have a great influence on the physical properties of the super absorbent resin (SAP), and is a network structure in the resin that constitutes the super absorbent resin (SAP). When the SAP is cross-linked using a cross-linking agent, the cross-linking part chemically exists. However, the cross-linking of the SAP with the dangling chain is also physically twisted between the dangling chain and the polymer chain. entanglement) forms. Knowing the extent of chain entanglement is helpful in understanding the initial properties of SAP and a way to analyze it.

In this regard, conventionally, Japanese Patent Laid-Open No. 2011-106728 discloses that by analyzing the flexibility of a molecule by measuring the T2 relaxation time value as the molecule becomes rigid by the NMR method, A method of determining the relative rigidity of a molecule has been disclosed. However, in the conventional methods, there is no case in which the physical properties of the superabsorbent resin are analyzed using the T2 relaxation time value.

Japanese Laid-Open Patent No. 2011-106728

The object of the present invention is to provide a CRC measuring method of a superabsorbent resin which can easily calculate the no-load absorption capacity (CRC) value of a superabsorbent resin after measuring the T2 relaxation time after swelling of the superabsorbent resin do.

For the above purpose,

The invention then swell the superabsorbent polymer (a) in D ₂ O and measuring the relaxation time T2; And (b) calculating a CRC value using the T2 relaxation time value of the step (a).

(A) a measurement module for swelling the superabsorbent resin with D ₂ O and measuring T2 relaxation time; And (b) calculating a CRC value using the T2 relaxation time value of the step (a).

The present invention also provides a computer readable recording medium on which a program for executing the above method is recorded.

According to the CRC measurement method of the superabsorbent resin of the present invention,

The CRC value of the superabsorbent resin can be easily calculated by measuring the T2 relaxation time alone.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view showing steps of producing a superabsorbent resin of the present invention. FIG.
2 is a graph showing the relationship between the CRC value of the example and the superabsorbent resin after swelling.

Hereinafter, the present invention will be described in detail.

The CRC measurement method of the superabsorbent resin according to the present invention is characterized in that,

(a) swelling the superabsorbent resin with D ₂ O and measuring T2 relaxation time; And

(b) calculating a CRC value using the T2 relaxation time value in the step (a).

In the CRC measurement method of the superabsorbent resin of the present invention, (a) T2 relaxation time is measured after swelling the superabsorbent resin with D ₂ O. When the superabsorbent resin is swollen with D ₂ O, mutual physical crosslinking between chains of the superabsorbent resin is removed, and only chemical crosslinking is formed.

As described above, when the superabsorbent resin is exposed to D ₂ O as a solvent, the solvent molecules penetrate into the chain gaps of the superabsorbent resin to increase the weight and volume of the polymer, thereby swelling the polymer , And accordingly, it is greatly changed by various factors such as the structure of the polymer (crystal structure or amorphous structure), the molecular weight, the molecular weight distribution, the characteristics of the solvent, and the physical crosslinking is removed by releasing the twisted polymer.

Here, D ₂ O was used because it was intended to measure only the T2 relaxation time of only the superabsorbent resin. For example, when H ₂ O is used, the amount of H ₂ O in the sample is higher than in the case of a superabsorbent resin sample, so most of the proton signals come out of H ₂ O and interfere with the signal of the superabsorbent resin. However, when D ₂ O is used, since the water proton is deuterium, no water signal appears and the relaxation time of only the superabsorbent resin can be measured.

The T2 relaxation time can be measured using a Time Domain NMR (TD NMR) apparatus. The T2 relaxation time is measured by the NMR method for analyzing the flexibility of the molecule. The T2 relaxation time value is measured as the molecule becomes stiff (faster) and the T2 relaxation time value becomes larger as the molecule becomes more flexible (Slow). This allows us to determine the relative rigidity of the molecule.

Wherein (a) according to step, and swelling of a water-absorbent resin according to the user settings, but can be performed according to various swelling levels, a variety of swelling temperature and a variety of swelling time, preferably solid solution a water-absorbent resin D ₂ O At a concentration of 0.005 to 0.05 g / L, and then swollen at 20 to 70 ° C for 12 to 36 hours. Most preferably, the superabsorbent resin is mixed with a D ₂ O solution at a concentration of 0.01 g / L, Lt; / RTI > for 24 hours.

Thereafter, in the CRC measurement method of the superabsorbent resin of the present invention, the CRC value is calculated using the T2 relaxation time value of the step (a) in the step (b).

The T2 relaxation time before swelling of the superabsorbent resin is affected by the chain entanglement which is the physical crosslinking and the crosslinking by the crosslinking agent which is the chemical crosslinking affects the rigidity of the molecule whereas swelling by D ₂ O The T2 relaxation time after the swelling is released, the physical crosslinking is released, and the chemical crosslinking mostly affects the rigidity of the molecule. That is, the superabsorbent resin swells and swells, and thus the effect of chain entanglement is greatly reduced, so that there is only the effect of chemical crosslinking. The present inventors have confirmed the correlation between the T2 relaxation time and the CRC value of the swollen superabsorbent resin from which the physical crosslinking has been removed, and the CRC value is measured using the T2 relaxation time value.

Specifically, the CRC value of the step (b) may be obtained by mixing the superabsorbent resin in a D ₂ O solution at a concentration of 0.005 to 0.05 g / L, and then swelling the mixture at 20 to 70 ° C for 12 to 36 hours. Can be obtained as follows.

[Formula 1]

y = ax + b

Wherein a is 25 to 35, b is 20 to 25, x is T2 relaxation time, and y is CRC value.

More specifically, the CRC value in the step (b) is preferably obtained by mixing the superabsorbent resin in a D ₂ O solution at 0.01 g / L and then swelling the mixture at 40 ° C for 24 hours. .

[Formula 2]

y = 36.196x + 12.004

(Where x is the T2 relaxation time and y is the CRC value)

As a method for producing the superabsorbent resin of the present invention,

As shown in Fig. 1 (a), the above superabsorbent resin is thermally polymerized or photopolymerized with a monomer composition comprising a water-soluble ethylenically unsaturated monomer, an internal crosslinking agent and a polymerization initiator. As shown in Fig. 1 (b), the polymerized superabsorbent resin is divided into an ideal meshed portion, a short-chain portion, and a sol portion. When this is crosslinked by using an internal crosslinking agent, crosslinked as shown in FIG. 1 (c), a superabsorbent resin (SAP) is formed which forms a hard shell and a soft core.

Another method for producing the superabsorbent resin is a method in which a monomer composition comprising the water-soluble ethylenically unsaturated monomer, an internal crosslinking agent and a polymerization initiator is thermally polymerized or photopolymerized, dried, pulverized and then crosslinked by adding a surface cross- And the composition is not limited as long as it is a commonly used polymerization method.

For the production of the superabsorbent resin, polymerization can be carried out by the steps and methods commonly used in the art. Specifically, in the preparation of a superabsorbent resin, the monomer composition includes a polymerization initiator. When the polymerization method is a photopolymerization method, a photopolymerization initiator is included. When the polymerization method is thermal polymerization, . However, even with the photopolymerization method, a certain amount of heat is generated by irradiation with ultraviolet radiation or the like, and a certain amount of heat is generated as the polymerization reaction, which is an exothermic reaction, proceeds.

The thermal polymerization initiator used in the production of the superabsorbent resin is not particularly limited, but preferably at least one selected from the group consisting of a persulfate-based initiator, an azo-based initiator, hydrogen peroxide, and ascorbic acid can be used. Specifically, examples of persulfate-based initiators include sodium persulfate (Na2S2O8), potassium persulfate (K2S2O8), ammonium persulfate (NH4) 2S2O8, and the like. Azo Examples of the initiator include 2, 2-azobis (2-amidinopropane) dihydrochloride, 2, 2-azobis- (N, Isobutyramidine dihydrochloride, 2,2-azobis- (N, N-dimethylene) isobutyramidine dihydrochloride, 2- (carbamoyl azo) isobutylonitrile, Azobis [2- (2-imidazolin-2-yl) propane] dihydrochloride), 4,4-azobis- (4-azobis- (4-cyanovaleric acid)) and the like can be used.

The photopolymerization initiator used in the preparation of the superabsorbent resin is not particularly limited, but is preferably a benzoin ether, a dialkyl acetophenone, a hydroxyl alkylketone, a phenyl At least one selected from the group consisting of phenyl glyoxylate, benzyl dimethyl ketal, acyl phosphine and alpha-aminoketone may be used. On the other hand, as a specific example of the acylphosphine, a commonly used lucyrin TPO, i.e., 2,4,6-trimethyl-benzoyl-trimethyl phosphine oxide can be used .

In the production of the superabsorbent resin, the water-soluble ethylenically unsaturated monomer is not particularly limited as long as it is a monomer usually used in the production of a superabsorbent resin, but preferably an anionic monomer and a salt thereof, A monomer, and an amino group-containing unsaturated monomer and a quaternary car- bon thereof. Specific examples include acrylic acid, methacrylic acid, maleic anhydride, fumaric acid, crotonic acid, itaconic acid, 2-acryloylethanesulfonic acid, 2- methacryloylethanesulfonic acid, 2- (meth) acryloylpropanesulfonic acid, - anionic monomers of (meth) acrylamido-2-methylpropanesulfonic acid and its salts; (Meth) acrylamide, N-substituted (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, methoxypolyethylene glycol (meth) acrylate or polyethylene glycol Non-ionic hydrophilic-containing monomer of (meth) acrylate; And at least one selected from the group consisting of unsaturated monomers containing an amino group of (N, N) -dimethylaminoethyl (meth) acrylate or (N, N) -dimethylaminopropyl (meth) And more preferably acrylic acid or its salt can be used.

In the preparation of the superabsorbent resin, the water-soluble internal crosslinking agent is not particularly limited as long as it is an internal crosslinking agent usually used in the production of a superabsorbent resin. Preferably, N, N-methylenebisacrylamide, trimethylolpropane tri (Meth) acrylate, propylene glycol di (meth) acrylate, ethylene glycol di (meth) acrylate, polyethylene glycol (meth) acrylate, propylene glycol di , Butylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, hexane diol di (meth) acrylate, triethylene glycol di (meth) acrylate, tripropylene glycol di , Tetraethylene glycol di (meth) acrylate, dipentaerythritol pentaacrylate, glycerin There can comprise a (meth) acrylate, pentaerythrityl stall tetraacrylate, triarylamine, ethylene glycol diglycidyl ether, propylene glycol, glycerin, and one or more selected from the group consisting of ethylene carbonate

The surface cross-linking agent to be added in the preparation of the superabsorbent resin is not limited in its constitution if it is a compound capable of reacting with the functional group of the polymer. As the surface cross-linking agent, a polyhydric alcohol compound, preferably a polyhydric alcohol compound, Epoxy compounds; Polyamine compounds; Halo epoxy compounds; A condensation product of a haloepoxy compound; Oxazoline compounds; Mono-, di- or polyoxazolidinone compounds; Cyclic urea compounds; Polyvalent metal salts; And an alkylene carbonate compound can be used.

Specific examples of the polyhydric alcohol compound include mono-, di-, tri-, tetra- or polyethylene glycol, monopropylene glycol, 1,3-propanediol, dipropylene glycol, 2,3,4-trimethyl- - pentanediol, polypropylene glycol, glycerol, polyglycerol, 2-butene-1,4-diol, 1,4-butanediol, 1,3-butanediol, 1,5-pentanediol, 1,2-cyclohexane dimethanol, and the like.

Examples of the epoxy compounds include ethylene glycol diglycidyl ether and glycidol. Examples of the polyamine compounds include ethylene diamine, diethylene triamine, triethylene tetramine, tetraethylene pentaamine, pentaethylene hexamine , Polyethyleneimine, and polyamide polyamines can be used.

As the haloepoxy compound, epichlorohydrin, epibromohydrin, and? -Methyl epichlorohydrin can be used. On the other hand, as the mono-, di- or polyoxazolidinone compounds, for example, 2-oxazolidinone and the like can be used. As the alkylene carbonate compound, ethylene carbonate and the like can be used. These may be used alone or in combination with each other. On the other hand, in order to increase the efficiency of the surface cross-linking step, it is preferable to use at least one polyhydric alcohol compound among these surface cross-linking agents, more preferably a polyhydric alcohol compound having 2 to 10 carbon atoms.

At this time, the composition of the method of adding the surface cross-linking agent to the polymer is not limited. A method in which a surface cross-linking agent and a polymer powder are mixed in a reaction tank or spraying a surface cross-linking agent onto a polymer powder, a method in which a polymer and a cross-linking agent are continuously supplied and mixed in a reaction vessel such as a continuously operated mixer.

Thereafter, in the surface cross-linking reaction, the polymer mixed with the surface cross-linking agent may be supplied to one surface cross-linking reactor, and the surface cross-linking reaction of the hydrous gel polymer may be carried out at a temperature of 160 to 200 ° C for 20 to 60 minutes.

In the present invention, after the surface cross-linking reaction as described above proceeds, a superabsorbent resin having a particle size of 150 mu m to 850 mu m can be obtained by classification into a standard mesh of ASTM standard.

The present invention also provides a computer readable recording medium on which a program for executing the above method is recorded.

The present invention provides a computer-readable recording medium on which a program for executing the above method is recorded.

(A) a measurement module for swelling the superabsorbent resin with D ₂ O and measuring T2 relaxation time; And (b) a calculation module for calculating a CRC value using the T2 relaxation time value of the measurement module.

In the CRC measurement system of the superabsorbent resin, the description of the configuration overlapping the CRC measurement method of the superabsorbent resin is the same.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the embodiments of the present invention described below are illustrative only and the scope of the present invention is not limited to these embodiments. The scope of the present invention is indicated in the claims, and moreover, includes all changes within the meaning and range of equivalency of the claims.

Example

[Example 1]

500 g of acrylic acid and 4 g of internal cross-linking agent N, N'-methylenebisacrylamide were added and mixed. Then, 0.01 g of diphenyl (2,4,6-trimethylbenzoyl) -phosphine oxide as a polymerization initiator was added and dissolved. Thereafter, 896.4 g of a sodium hydroxide solution having a concentration of 24.5% by weight was added, and nitrogen was continuously added to prepare an aqueous solution of a water-soluble unsaturated monomer. Subsequently, the temperature of the solution was cooled to 60 DEG C, and ultraviolet rays were irradiated to the aqueous solution for 90 seconds to obtain a hydrogel polymer. The obtained hydrogel polymer was pulverized and then dried in a hot-air dryer at a temperature of 180 DEG C for 30 minutes, and the dried hydrogel polymer was pulverized using a pulverizer. Thereafter, the resultant was classified into a standard mesh of ASTM standard to obtain a base resin powder (powdery superabsorbent resin) having a particle size of 150 mu m to 850 mu m.

The T2 relaxation time after the swelling of the powdery superabsorbent resin was measured using the Minispec mq20 Polymer Research System of Bruker. Solid 0% daily check samples were used for tune / pulse calibration of the Minispec instrument.

To measure the T2 relaxation time of the powdery superabsorbent resin after swelling, 5 ml of D ₂ O was added to 50 mg of the powdery superabsorbent resin prepared above, and swelled at 40 ° C for 24 hours. The T2 relaxation time was measured using the T2_se_mb application, and the first tau was 0.01 msec, the last tau was 30 msec, the data point was 100, the delay time was 30 sec, and scans 4.

 [Example 2]

A superabsorbent resin was prepared and the T2 relaxation time was measured in the same manner as in Example 1, except that 2.2 g of N, N'-methylenebisacrylamide was used as an internal crosslinking agent.

[Example 3]

A superabsorbent resin was prepared and the T2 relaxation time was measured in the same manner as in Example 1, except that 1.5 g of N, N'-methylenebisacrylamide was used as an internal crosslinking agent.

[Example 4]

A superabsorbent resin was prepared and the T2 relaxation time was measured in the same manner as in Example 1, except that 0.7 g of N, N'-methylenebisacrylamide was used as an internal crosslinking agent.

Experimental Example

The T2 relaxation time after swelling of the superabsorbent resin of Examples 1 to 4, the molecular weight of the superabsorbent resin and the CRC value were measured and are shown in Table 1 below.

The CRC was measured by homogenizing the SAP resin (W (g)) in an envelope made of a nonwoven fabric, sealing it, immersing it in 0.9% by mass of physiological saline at room temperature, 30 minutes later, using a centrifuge, (G) of the envelope was measured after removing the water for 3 minutes, and the mass W1 (g) at that time was measured after the same operation was performed without using the resin. Using the obtained masses, To calculate CRC (g / g).

[Formula 3]

CRC (g / g) = {(W2 (g) -W1 (g)) / W (g)

The measurement of the molecular weight was carried out by the following method

First, in order to measure the weight average molecular weight of the superabsorbent resin, crosslinking points were artificially cut off and sampled in a linear chain. As a method for pretreating a sample of a superabsorbent resin, see J. applied 중합체 science 1995, 55, 605-609, Journal of Polymer Science : Part B: Polymer Physice , 1997, 35, 2029-2047 ). 0.4 g of the superabsorbent resin was placed in 1 N NaOH (100 ml), 0.4 g of MEHQ was further added, and the mixture was placed in an oven at 75 ° C for 7 days to allow the hydrolysis reaction to proceed. After the hydrolysis reaction, the sample was diluted with GPC solvent (0.1 M NaNO ₃ + pH 7.0 phosphate buffer) to approximately 0.8 mg / mL. The GPC column used for the analysis was a Waters ultrahydogel linear X 2, and the temperature in the column was adjusted to 40 ° C and the flow rate to 1.0 mL / min. The detector uses an RI detector. When the instrument was stabilized, a weight average molecular weight was measured by injecting a reference material (7 kinds of poly (acrylic acid)) and a measurement sample.

Molecular weight (g / mol) CRC (g / g) T2 r.t. (swelling) Example 1 1.66 x 10 ⁶ 30 0.50 0.07 Example 2 1.59 × 10 ⁶ 33 0.59 + 0.09 Example 3 1.61 x 10 ⁶ 38 0.7 ± 0.1 Example 4 1.56 x 10 ⁶ 48 1.0 ± 0.1

The relationship between the T2 relaxation time and the CRC value after swelling in Examples 1 to 4 according to the results of Table 1 is shown in Fig.

As shown in FIG. 2, it is confirmed that the change of the CRC value according to the increase of the T2 relaxation time has a direct correlation with the following equation (2).

[Formula 2]

y = 36.196x + 12.004

(Where x is the T2 relaxation time and y is the CRC value)

Thus, it was found that the CRC value can be estimated or directly calculated by T2 relaxation time measurement without direct CRC measurement.

Claims (19)

(a) swelling the superabsorbent resin with D ₂ O and measuring T2 relaxation time; And
(b) calculating a CRC value using the T2 relaxation time value of step (a)
The superabsorbent resin is obtained by thermally polymerizing or photopolymerizing a monomer composition comprising a water-soluble ethylenically unsaturated monomer, an internal cross-linking agent and a polymerization initiator, or by thermally polymerizing or photopolymerizing the monomer composition after crosslinking by adding a surface cross-
The swelling in the step (a) is carried out by swelling the superabsorbent resin in a D2O solution at 0.01 g / L at 40 DEG C for 24 hours,
Wherein the CRC value of the step (b) is calculated using the following formula (2).
[Formula 2]
y = 36.196x + 12.004
(Where x is the T2 relaxation time and y is the CRC value) delete delete delete delete The method according to claim 1,
The water-soluble ethylenic unsaturated monomer may be at least one selected from the group consisting of acrylic acid, methacrylic acid, maleic anhydride, fumaric acid, crotonic acid, itaconic acid, 2- acryloylethanesulfonic acid, 2- methacryloylethanesulfonic acid, 2- (meth) (Meth) acrylamide, N-substituted (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxy (N, N) -dimethylaminopropyl (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, polyethylene glycol (meth) acrylate, Methacrylic acid, methacrylic acid, methacrylic acid, methacrylic acid, methacrylic acid, methacrylic acid, methacrylic acid, and methacrylic acid. The method according to claim 1,
(Meth) acrylate, polyethylene glycol (meth) acrylate, propylene glycol di (meth) acrylate, poly (meth) acrylate, (Meth) acrylate, propylene glycol (meth) acrylate, butane diol di (meth) acrylate, butylene glycol di (meth) acrylate, diethylene glycol di (Meth) acrylate, glycerin tri (meth) acrylate, pentaerythritol tetraacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, pentaerythritol triacrylate, Triarylamine, ethylene glycol diglycidyl ether, propylene glycol, glycerin, and ethylene CRC measurement method of super-absorbent resin, characterized in that at least one selected from the group consisting of carbonate. The method according to claim 1,
The polymerization initiator may be at least one selected from the group consisting of sodium persulfate (Na2S2O8), potassium persulfate (K2S2O8), ammonium persulfate (NH4) 2S2O8, 2, 2-azobis- (2-amidinopropane) (2,2-azobis- (N, N-dimethylamino) isobutyraldehyde dihydrochloride, 2,2-azobis- 2-azobis [2- (2-imidazolin-2-yl) propane] di (isobutyramide dihydrochloride), 2- (carbamoylazo) isobutylonitrile, 2-yl) propane] dihydrochloride), 4,4-azobis- (4-azobis- (4-cyanobalenoic acid) cyanovaleric acid), benzoin ether, dialkyl acetophenone, hydroxyl alkylketone, phenyl glyoxylate, benzyl dimethyl ketal, acyl Acyl phosphine And alpha-aminoketone. The method for measuring CRC of a superabsorbent resin according to claim 1, The method according to claim 1,
The surface cross-linking agent may be selected from the group consisting of mono-, di-, tri-, tetra- or polyethylene glycol, monopropylene glycol, 1,3-propanediol, dipropylene glycol, 2,3,4-trimethyl- Propylene glycol, glycerol, polyglycerol, 2-butene-1,4-diol, 1,4-butanediol, 1,3-butanediol, 1,5-pentanediol, But are not limited to, hexane dimethanol, ethylene glycol diglycidyl ether, glycidol, ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, polyethyleneimine, polyamidepolyamine, epichlorohydrin , Epibromohydrin,? -Methyl epichlorohydrin, 2-oxazolidinone, and ethylene carbonate. (a) a measurement module for swelling the superabsorbent resin with D ₂ O and measuring the T2 relaxation time; And
(b) a calculation module for calculating a CRC value using the T2 relaxation time value of the measurement module,
The superabsorbent resin is obtained by thermally polymerizing or photopolymerizing a monomer composition comprising a water-soluble ethylenically unsaturated monomer, an internal cross-linking agent and a polymerization initiator, or by thermally polymerizing or photopolymerizing the monomer composition after crosslinking by adding a surface cross-
The swelling in the step (a) is carried out by swelling the superabsorbent resin in a D2O solution at 0.01 g / L at 40 DEG C for 24 hours,
Wherein the CRC value of the step (b) is calculated using the following equation (2).
[Formula 2]
y = 36.196x + 12.004
(Where x is the T2 relaxation time and y is the CRC value) delete delete delete delete The method of claim 10,
The water-soluble ethylenic unsaturated monomer may be at least one selected from the group consisting of acrylic acid, methacrylic acid, maleic anhydride, fumaric acid, crotonic acid, itaconic acid, 2- acryloylethanesulfonic acid, 2- methacryloylethanesulfonic acid, 2- (meth) (Meth) acrylamide, N-substituted (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxy (N, N) -dimethylaminopropyl (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, polyethylene glycol (meth) acrylate, Methacrylic acid, methacrylic acid, methacrylic acid, methacrylic acid, methacrylic acid, methacrylic acid, and methacrylic acid. The method of claim 10,
(Meth) acrylate, polyethylene glycol (meth) acrylate, propylene glycol di (meth) acrylate, poly (meth) acrylate, (Meth) acrylate, propylene glycol (meth) acrylate, butane diol di (meth) acrylate, butylene glycol di (meth) acrylate, diethylene glycol di (Meth) acrylate, glycerin tri (meth) acrylate, pentaerythritol tetraacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, pentaerythritol triacrylate, Triarylamine, ethylene glycol diglycidyl ether, propylene glycol, glycerin, and ethylene Carbonate CRC measurement system of the superabsorbent resin, characterized in that at least one selected from the group consisting of. The method of claim 10,
The polymerization initiator may be at least one selected from the group consisting of sodium persulfate (Na2S2O8), potassium persulfate (K2S2O8), ammonium persulfate (NH4) 2S2O8, 2, 2-azobis- (2-amidinopropane) (2,2-azobis- (N, N-dimethylamino) isobutyraldehyde dihydrochloride, 2,2-azobis- 2-azobis [2- (2-imidazolin-2-yl) propane] di (isobutyramide dihydrochloride), 2- (carbamoylazo) isobutylonitrile, 2-yl) propane] dihydrochloride), 4,4-azobis- (4-azobis- (4-cyanobalenoic acid) cyanovaleric acid), benzoin ether, dialkyl acetophenone, hydroxyl alkylketone, phenyl glyoxylate, benzyl dimethyl ketal, acyl Acyl phosphine And alpha-aminoketone. 9. The CRC measurement system of claim 8, The method of claim 10,
The surface cross-linking agent may be selected from the group consisting of mono-, di-, tri-, tetra- or polyethylene glycol, monopropylene glycol, 1,3-propanediol, dipropylene glycol, 2,3,4-trimethyl- Propylene glycol, glycerol, polyglycerol, 2-butene-1,4-diol, 1,4-butanediol, 1,3-butanediol, 1,5-pentanediol, But are not limited to, hexane dimethanol, ethylene glycol diglycidyl ether, glycidol, ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, polyethyleneimine, polyamidepolyamine, epichlorohydrin , Epibromohydrin,? -Methyl epichlorohydrin, 2-oxazolidinone, and ethylene carbonate. A computer-readable recording medium having recorded thereon a program for executing the method according to any one of claims 1 to 6.

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