The present invention and showing the basic absorption performance as well as excellent and improved absorption rate and the barrel-component in a circle about the water-absorbent resin and a production method thereof.

[Background Art]

Superabsorbent polymer (Super Absorbent Polymer, SAP) is a synthetic polymer material that has the ability to absorb about 500 to 1000 times the water of its own weight, developers every SAM (Super Absorbency Material), AGM (Absorbent Gel Material), etc. are each named with a different name. Superabsorbent polymer as described above is to begin commercialization of physiological equipment, currently freshness at Children diapers, etc. sanitary ware in addition to horticultural soil repair filler, engineering, construction index material, nursery sheets, food for distribution areas first, and It has been widely used for a material such as a poultice.

. The in many cases, there Such super-absorbent resin is widely used in hygienic material fields, such as diapers and sanitary napkins, for this purpose it is necessary to exhibit a high absorption capacity for such as moisture, should have absorbed moisture to an external pressure not get out, and in addition, it is necessary to exhibit excellent liquid cylinder (permeability) to maintain the well in the form of a water absorbs volume expansion (swelling) state.

Recently, there is a tendency that, depending on the requirements for the thin diaper to expand, reducing the pilpeu such as a fiber material content in the diaper, and the relatively high increase in the proportion of the water-absorbent resin. Thus, the high performance fiber of the diaper was in charge of material and the need to combine the water-absorbent resin, to have a high To this high absorption capacity of the water-absorbent resin, as well as high absorption rate and the barrel-component.

And to indicate that the high cylinder liquid by the above-mentioned water-absorbent resin, and the basically its shape even after water-absorbent resin particles are swollen by absorbing water

Maintained it is necessary to keep the air gap between the particles and the particles. This is because the gap between the particles can guarantee an excellent bottle of liquid absorbent resin and the euro act. Therefore, the improved barrel and other liquid exhibits excellent physical properties , and to provide a water-absorbent resin, there is such a superabsorbent polymer must point to a higher gel strength,

In addition, the high to indicate a higher absorption rate than the water-absorbent resin, it exhibited a porous structure in which numerous fine pores formed therein or, the crosslinking density needs to be relatively low within the controllable.

However, when has the porous structure, or producing a water absorbent resin and a low internal cross-linking density, and since there will be times when that is the gel strength of the water absorbent resin decreases, formerly cylindrical liquid and the absorbing speed and enhanced at the same time a water-absorbent resin is properly developed a situation that does not.

Furthermore, in the case that you want to increase the gel strength of the water-absorbent resin, generally and basic that absorption capacity is known to degrade bar, and excellent as possible maintain the ability to absorb while improving gel strength, and through liquid absorbent resin of the water-absorbent resin it is true that even had the technical difficulty in.

Thus, while maintaining the excellent absorption performance, the improved cylinder and liquid absorption rate . This indicates that while the development of technologies that can provide a water-absorbent resins are continually required.

[Detailed Description of the Invention]

[SUMMARY]

The present invention is not only excellent in the basic absorption performance, and to represent the improved absorption rate and the barrel-component such as provide an absorbent resin and a production method thereof.

[How to solve technical]

The present invention is a base resin powder including a first cross-linked polymers of water soluble ethylenically unsaturated monomer having at least partially neutralized acid; And

A super-absorbent resin to the first cross-linked polymer is formed on the base resin powder, a cross-linked layer includes a surface that includes an additional cross-linked second cross-linked polymer as a medium of an alkylene carbonate having 2 to 5,

An absorbency of from 45 to 65g / g represented by the following formula 1,

; (10 SFC physiological saline (0.685% by weight aqueous solution of sodium chloride) induced flow of " 7 cm 3 s / g) of 40 to 80C 10 1 -7 cm 3 , and s / g),

30 seconds absorption rate for physiological saline solution under pressure of 0.3 psi is more than 1.5mm / min, and having a high porosity of 20% or more provides a water-absorbent resin:

[Equation 1]

Absorbency = CRC + AUP

In the formula 1,

CRC is the high denotes a beam SAT centrifugation for 30 min on saline (0.9 wt% aqueous sodium chloride solution) of a water-absorbent resin,

AUP is a high saline solution (0.9 parts by weight of a water-absorbent resin 0 represents the absorption capacity of the pressure for one hour under a 0.7psi on /. Aqueous sodium chloride solution).

The present invention is a base resin powder including a first cross-linked polymers of water soluble ethylenically unsaturated monomer having at least partially neutralized acid; And

A super-absorbent resin to the first cross-linked polymer is formed on the base resin powder, a cross-linked layer includes a surface that includes an additional cross-linked second cross-linked polymer as a medium of an alkylene carbonate having 2 to 5,

An absorbency of from 45 to 65g / g represented by the formula 1,

; (10 SFC physiological saline (0.685% by weight aqueous solution of sodium chloride) induced flow of ' 7 cm 3 s / g) of 48 to 180 (' 10 "7 cm 3 , and s / g),

30 seconds absorption rate for physiological saline solution under pressure of 0.3 psi and provides the super-absorbent resin of 1.5mm / min to 3.0mm / min.

The present invention also comprising the steps of: in the presence of an internal crosslinking agent, a polymerization cross-linking a water-soluble ethylenically unsaturated monomer having at least some of the neutralizing acid, including a first crosslinked polymer, forming a hydrogel polymer having a gel strength of at least lOOOOPa;

The method comprising the gel strength after the grinding function of the gel polymer gel to be ground to a 35% to 90% of the gel strength before the cutting;

The gel is comminuted function drying the polymer gel, thereby forming a crushing and classifying to a base resin powder;

50 for the water on the base resin powder ° step of adding the hydrophobic inorganic particles having the above contact angle; And

10 for the water ° hydrophilic inorganic particles having a contact angle of less than, and in the presence of a surface cross-linking solution containing the surface crosslinking agent of the alkylene carbonate having 2 to 5, the surface of heat-treating the hydrophobic inorganic particle is added a base resin powder and including the step of cross-linking provides a method for producing a water-absorbent resin.

Hereinafter, there will be more fully describes the collection of specific embodiments and the water-absorbent resin and its production process according to the invention. However, it is to be presented as an illustration of the invention and thus is not limited by the scope of the invention, it is apparent to those skilled in the art are possible are various modifications to the embodiments within the scope of the invention. Additionally, the term a "contains" or "containing" not otherwise specified throughout this specification, refers to including without limitation any component (or components), the addition of the other component (or components) It can not be interpreted to exclude.

According to one embodiment of the invention, the base resin powder including a first cross-linked polymers of water soluble ethylenically unsaturated monomer having at least partially neutralized acid; And to a super-absorbent resin to the first cross-linked polymer is formed on the base resin powder comprises a surface cross-linked layer that includes an additional cross-linked second cross-linked polymer as a medium of an alkylene carbonate having 2 to 5, an absorbency of from 45 to 65g / g of formula 1, induced flow of physiological saline (0.685% by weight aqueous solution of sodium chloride) (SFC; 10- 7 cm 3 's / g) of 40 to 180 (' Kr 7 cm 3 s / g), and 30 and superabsorbent speed is 1 .5mm / min or more for a physiological saline solution under pressure of 0.3 psi, a super-absorbent resin having a porosity of 20% or more is provided.

The continuous experiments by the inventors result, also keep the, cross-linking polymerization to obtain a hydrogel polymer having a high gel strength by controlling the conditions, the gel strength of the appropriate range after the control thereof, the gel pulverization conditions gel pulverization according to the method described below after Messenger, if and after the surface cross-linking step using the specific inorganic particles made of a water-absorbent resin, it confirmed that the basic absorption capacity as well as superior, barrel-component, and the absorption rate can be significantly enhanced and provides manufacturing and water-absorbent resin to the invention

It was completed.

That is, by default, the gel strength is gained high hydrogel polymer, a gel, these functions, as the gel strength of the gel polymer to adjust the gel pulverization conditions to be maintained above a certain level, the base resin powder relative to exhibiting a high gel strength after grinding this can be provided. Moreover, in the case of proceeding to the surface cross-linking step using an inorganic particle of the plurality of types, are of the inorganic particles are uniformly distributed on the chopping AAS resin powder, the surface cross-linked layer having a certain level of thickness can be formed uniformly have. Accordingly, the thus-formed one embodiment the superabsorbent resin is a resin comprising a base powder and / or the surface cross-linked layer is both more nopeumyeonseo also have a uniform intensity to this, but can exhibit improved gel strength than a whole. As a result, one embodiment the superabsorbent resin can exhibit excellent liquid tube and, under pressure, such as absorption performance, which is defined by a high AUP is defined by the relatively high SFC or the like.

Further, by gel pulverization proceeds under the specific conditions, contains a plurality of pores having a certain level of porosity, since the surface area of ​​the large base resin powder and the super-absorbent resin can be obtained, an implementation example super-absorbent resin is, for for example, it was confirmed that can exhibit an enhanced absorption rate than that defined by the physical properties such as the absorption speed of 30 seconds with.

In addition, basically, high gel. After obtaining a hydrogel polymer with a strength depending on the grinding conditions to control the gel maintains the gel strength after grinding a certain level, one embodiment obtained through this method, super-absorbent resin can reduce the degradation of the absorption performance.

Thus, in one embodiment , super-absorbent resin is, yet can maintain the excellent performance of the basic absorbent, and can exhibit such improved absorption rate and the barrel-component, it can be preferably applied to the diaper such as sanitary material having a thinner thickness.

Ah, and one embodiment will now be described in more detail on the water-absorbent resin.

Further, "as referred to herein, and the water absorbent resin, is a base resin powder including a first cross-linked polymers of water soluble ethylenically unsaturated monomer having at least partially neutralized acid; And that means the water absorbent resin including the resin powder is formed on the base, wherein the added crosslinked with a surface cross-linked layer, including two cross-linked polymer with the surface cross-linking agent intermediate the first cross-linked polymer.

The water-soluble ethylenically unsaturated monomer may be any monomer that is commonly used in the manufacture of a superabsorbent polymer. Non-limiting examples of the water-soluble ethylenically unsaturated monomer may be a compound represented by the following general formula (1):

Formula 1

COOM-RI 1

In the formula 1,

^ Is an alkyl group of 2 to 5 carbon atoms including an unsaturated bond,

M 1 is a hydrogen atom, or one divalent metal, an ammonium group or an organic amine salt. Suitably, the monomer may be at least one member selected from acrylic acid, methacrylic acid, and mixtures thereof with mountain monovalent metal salt, a divalent group consisting of metal salts, ammonium salts and organic amine salts thereof. Thus, when using the water-soluble ethylenically unsaturated monomer, acrylic acid or its salt in the water-absorbent high improved. It is advantageous to obtain a water-absorbent resin. In addition, one-propanesulfonic acid in the monomer to maleic anhydride, fumaric acid, crotonic acid, itaconic acid, ethanesulfonic acid one by one ethanesulfonic acid, 2-methacryloyloxyethyl 2-acrylate, 2- (meth) acrylate, or 2- ( meth) anionic acrylamide-2-methylpropanesulfonic acid monomer and its salts; (Meth) acrylamide, N- substituted (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, methoxy polyethylene glycol, hydroxyethyl (meth) acrylate or polyethylene glycol ( meth) non-ionic hydrophilic monomers containing acrylate; And (N, N) - dimethylaminoethyl (meth) acrylate or (Ν, Ν) - amino group-containing unsaturated monomer of dimethylaminopropyl (meth) acrylamide and his

Quaternary cargo; as may be used at least one selected from the group consisting of.

Here, the water-soluble ethylenically unsaturated monomer having an acidic group, may be at least partially neutralizing the acid groups. Preferably it is used which is partially neutralized the monomers with an alkali substance such as sodium hydroxide, potassium hydroxide, ammonium hydroxide.

In this case, the neutralization degree of the monomer is 40 to 95 mole 0 /., Or 40 to 80 mole 0 may be a /., Or 45 to 75 mol%. Range of the degree of neutralization may be different depending on the final physical properties, the degree of neutralization precipitation is too high, the neutralized monomer may be difficult to polymerization proceeds smoothly, whereas if the degree of neutralization is too low, as well as degrade the polymeric absorbent significantly handling can exhibit properties such as hard rubber.

The means that the "first crosslinked polymer" refers to the above-described water-soluble ethylenically unsaturated monomer polymerization to the presence of internal cross-linking agent cross-linked, the "base resin powder, and means a material containing such a first crosslinked polymer. In addition, the 'means that the second crosslinked polymer is, more cross-linked material by cross-linking the first polymer is a parameter for the surface cross-linking agent, and thus is formed on the base resin powder. It will be described later to the surface cross-linking agent.

One embodiment the superabsorbent resin is superior in the basic pressure, or no pressure, absorption capability, absorption speed and the barrel-component, which by the physical properties such as CRC, AUP, absorbency, SFC, 30 superabsorbent speed, porosity or FSR It can be defined.

Specifically, in one embodiment the superabsorbent resin is a saline solution (0.9 weight 0 / 0 by centrifugation for 30 minutes beam SAT (CRC) is 24 to 35 g / g, or 26 to 32 g / g for the aqueous sodium chloride solution) It can be. This centrifugation beam SAT (CRC) range may define a pressureless excellent absorption performance and high-absorbent resin that indicates an implementation example.

Centrifugation beam SAT (CRC) for the physiological saline solution is then absorbed by the saline solution through the superabsorbent polymer in 30 minutes can be calculated by the following formula 1 of:

[Equation 1]

CRC(g/g) = {[W2(g) - W,(g) - Wo(g)]/W0(g)}

In the formula 1,

W 0 (g) is the initial weight (g) of the superabsorbent resin,

And W ^ g) is the weight measured after then impregnated for 30 minutes in physiological saline, dehydrated by using a centrifuge 3 minutes at 250G the nonwoven envelope without inserting the superabsorbent polymer at room temperature,

W 2 (g) is a high-absorbent resin into a nonwoven fabric bag at room temperature is a weight measured after then impregnated with physiological saline for 30 minutes using a centrifuge dehydrated 3 minutes at 250G.

In addition, the super-absorbent resin according to one embodiment may be in the absorption capacity under pressure (AUP) is 22 to 28 g / g, or 23 to 27 g / g. The absorption capacity under pressure (AUP) range may define the ability to absorb high pressure, and the water-absorbing resin showing an implementation example.

The absorption capacity under pressure (AUP) can be calculated by the after absorption of physiological saline under pressure of 0.7 psi, following equation 2 across the superabsorbent polymer in an hour.:

[Formula 2]

AUP (g / g) = [W 4 (g) - W 3 (g)] / W 0 (g)

In the formula 2,

W 0 (g) is the initial weight (g) of the superabsorbent polymer, W 3 (g) is a total sum of the unit weight which can impart a load to the weight and the high water-absorbent resin having a high water-absorbent resin, W 4 (g ) is the sum of the weight device which can impart a load to the weight and the high water-absorbent resin of the first and the period of time after absorption of saline solution to the water-absorbent resin, and water-absorbent resin under load (0.7 psi).

Further, according to indicate an implementation example super-absorbent resin is centrifuged beam SAT (CRC) and a pressure absorption capacity (AUP) of the above-mentioned range, the super-absorbent resin has absorbency of from 45 to 65g / g, which is defined by the formula 1, or it may be a 50 to 60g / g. Accordingly, one embodiment the superabsorbent resin is expressed as excellent absorption performance, such as the basic absorption and absorption under pressure retention can be suitably used for various sanitary materials.

Further, one embodiment the superabsorbent resin is flow-induced (SFC, 1 coming from the physiological saline (0.685% by weight aqueous solution of sodium chloride) 7 cm 3 s / g) of 40 to 180 (- 10- 7 cm 3 s / g), or 48 to 180 (10- 7 cm 3 s / g), or 48 to 150 (· 10 "7 cm 3 -s / g), or 60 to 130 (10- 7 may be in cm ^ s / g) .

The induction Saline Flow (SFC) is a method well-known to those skilled in the art before, for example, it can be measured and calculated according to the method disclosed in U.S. Patent No. 5,562,646 arc column 54 to column 59.

The super-absorbent resin is the base resin particles to maintain a high gel strength

Include, thereby to as including a surface cross-linked layer having a high strength is the only the tables cross-linking proceeds, under certain conditions, may have a high gel strength as a whole, whereby the improved saline flow induced (SFC) and the superior cylindrical liquid a it can be expressed.

More specifically, these high water-absorbent resin is a horizontal gel strength G 'is

8,500 to 18,000 Pa, black may indicate a characteristic 8,500 to 15,000 Pa.

The horizontal gel strength G 'may better reflect the superior cylindrical liquid under the actual use environment of the super-absorbent resin. That is, the normal gohop aqueous resin barrel-component is such that the water-absorbent resin is a diaper sanitary when it was embedded in the material, determined more relevant higher, depending on whether despite the force applied to the horizontal force and shows good shape-retaining properties and high gel strength may, the horizontal gel. intensity may reflect the gel strength associated with this cylinder liquid directly well. Thus, the horizontal direction such gel strength G, be implemented to meet the above-mentioned range and a water-absorbent resin, has been found to be usable is very desirable for diapers such as sanitary material according to indicate superior barrel-component.

The horizontal gel strength G ', and after absorption of physiological saline for 1 hour, the water-absorbent resin, by using a commercially available rheometer, and it can be measured by a method comprising the following the steps of:

1) a step of swelling by the number of hops and the saline solution to the water-absorbent resin; 2) the step of positioning the swollen superabsorbent polymer between the plates of a rheometer having a predetermined distance and presses the both side plates;

3) the step of using the oscillation rheometer under increasing shear strain, stored check shear deformation of the elastic modulus (storage modulus) and a loss elastic modulus (loss modulus), a constant linear viscoelastic conditions (linear viscoelastic regime) duration; And

4) comprises a storage tanseongreul and a loss elastic modulus of the swollen superabsorbent resin in the above-identified shear strain are measured, and measuring the average value of the storage tanseongreul as a gel strength.

On the other hand, that the aforementioned one embodiment the water absorbent resin, when a super-absorbent resin of about 0.16g be 0.3psi swelling under a pressurized condition by the physiological saline solution introduced through a mesh (mesh) of the cylindrical cylinder lower portion, a 30-second absorption rate 1.5mm / min or more, or 1.7mm / min to 3.0mm / min, the black can be as 1.8mm / min to 2.6mm / min. These 30 superabsorbent speed can be measured and calculated as a value divided by the rheometer absorption time (30 seconds), the height change of the upper plate according to the volume expansion of the superabsorbent resin.

The super-absorbent resin is high gel strength and thus indicating an excellent tube-component also, the above-described according to a gel pulverizing condition of the manufacturing process is controlled has a porous structure therein in accordance with 30 excellent eu absorption rate is defined as the second absorbing speed range It may represent the same time. Thus, the super-absorbent resin can be preferably used in the hygiene material of reduced fiber content, such as pulp material.

The one embodiment and to the water-absorbent resin can exhibit an excellent absorption rate, and barrel-component as described above, the super-absorbent resin is more than 20%, or 20% to 40%, or 21% to 30%, or 21% to It may have a porous structure that meet the porosity of 27%. According to the satisfaction of such a porosity range of said high with all the water-absorbent resin can exhibit an excellent absorption speed, high porous structure without adversely affecting the high gel strength it is possible that the water absorbent resin can be represented with a good barrel-component.

The void ratio is the above-described high and measurable at the same time: 30 superabsorbent speed measurement of the water-absorbent resin, the total volume (final absorption height * cylindrical cylinder of the inner cylinder when the high-absorbent resin in the 30 superabsorbent speed the measurement process is the swelling is complete, by measuring the volume of the physiological saline absorbed by the water content measuring instrument in a lower surface area) it can be calculated by subtracting from the total volume.

As described above, one embodiment the superabsorbent resin can be optimized gel pulverization conditions of hydrogel polymer, comprising a base resin powder having a porous structure and a large surface area in a production process. Therefore, the super-absorbent resin can exhibit an improved rate of absorption than those previously known.

Further, one embodiment the superabsorbent resin, and a water-absorbent resin 1 g of 0.9 wt. 0 / 0 speed to absorb the aqueous solution of sodium chloride 20 g (FSR, free Swell Rate) is 0.30 g / g / s or more, or 0.31 g It can be a / g / s or more. The FSR is limitation but the upper limit, for example 0.40 g / g / s or less, 0.39 g / g / s or less, 0.38 g / g / s or less, 0.37 g / g / s or less, or 0.36 g / g / s may be as follows. The FSR range and also illustrating one implementation it is possible to define a high absorption rate indicated by the water-absorbent resin.

On the other hand, in the super-absorbent resin mentioned above one embodiment, the first cross-linking polymer contained in the base resin powder is trimethylolpropane tri (meth) acrylate, ethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate acrylate, propylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, butane dayieul di (meth) acrylate, butylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, nucleic acid dayieul di (meth) acrylate, triethylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, di-penta-erythro little pentaacrylate, glycerin tri (meth ) consisting of acrylate and penta-erythro frame tetraacrylate Poly (meth) acrylate of polyols selected from the. Acrylate-based first internal cross-linking agent; And an allyl (meth) acrylate 2 in the presence of an internal crosslinking agent, the monomer may be polymerized as a crosslinked polymer. These two kinds of ahsangwa by the particular application of the internal cross-linking agent, illustrating one implementation of super-absorbent resin will contain a base resin powder after proceeding the like gel, crushing and grinding, maintaining a high gel strength, and therefore, more excellent tube-component and pressure, may exhibit such as absorption performance.

Further, the above-mentioned super-absorbent resin is surface cross-linked when the inorganic particles, more specifically, more than 50 ° with respect to water, or 50 ° and hydrophobic inorganic particles having a contact angle to 175 °, less than 10 ° against water, or one to It may be hydrophilic inorganic particles having a contact angle of 10 °. Accordingly, one embodiment superabsorbent polymer may further include inorganic particles dispersed in the surface cross-linked layer on the base resin powder. More specifically, the super-absorbent resin may further include a hydrophobic inorganic particles dispersed on the base resin powder, a hydrophilic inorganic particle. The hydrophobic inorganic particles include, for example, at least, and some may be present in the (in the example, the surface cross-linked layer) surface of the above base resin powder, and the remainder or get stuck to the surface of a base resin powder embedded therein state as it may be present. In addition, the hydrophilic inorganic particles may be in a state within the second cross-linking of the cross-linked polymer structure of the surface cross-linked layer, or embedded in the surface of the surface cross-linked layer.

As Thus barrel present on the inorganic particles have at least a base resin powder for liquid increase, despite the passage of time and can be maintained to keep barrel-component improves due to, in particular, the external force even if the applied high gel strength and there is enhanced through liquid can be maintained.

As the hydrophobic inorganic particles may be used one or more selected from the group consisting of silica particles, titania particles and the zirconia particles having the above-described contact angle range, the hydrophilic inorganic particles are silica having a contact angle in the range of 10 or less particles may be used one or more selected from the group consisting of titania particles, zirconia particles, and laponite particles.

Then, the contact angle with water, each of the separate hydrophilic and hydrophobic inorganic particles may be defined as a contact angle for water of the inorganic particles coated on the glass substrate. Specific measuring method of the contact angle of these are described in the following examples. The above-described one embodiment and the water absorbent resin may have a particle size of 150 to 850. More specifically, the base resin powder and a high-containing it at least 95 parts by weight of a water-absorbent resin 0 /. Above the embracing of a 150 to 850 diameter, a fine powder having a particle size of less than 150 3 parts by weight 0 can be less than /. .

The superabsorbent resin On the other hand, satisfy the various properties example described above one embodiment is then obtained a hydrogel polymer showing a higher gel strength is the cross-linking polymerization condition control, the gel strength after is controlled milling such gel pulverization conditions at a constant level and maintaining, atda finally be prepared by a manufacturing method comprising a surface cross-linking step to proceed in the presence of certain inorganic particles.

" According to another embodiment of the invention, there is provided a method of manufacturing the above-mentioned super-absorbent resin. This manufacturing method comprises the steps of polymerizing cross-linking the water-soluble ethylenically unsaturated monomer having under the. Presence of an internal crosslinking agent, at least a group partially neutralized acid including a first crosslinked polymer, forming a hydrogel polymer having at least l OOOOPa gel strength .; The method comprising the gel strength after the grinding function of the gel polymer gel to be ground to a 35% to 90% of the gel strength before the cutting; Forming a gel-pulverizing the dried hydrogel polymer increases, pulverized and classified to a base resin powder; Adding a hydrophobic inorganic particle having the above contact angle of 50 ° with respect to water on the base resin powder; And 10 ° for water . Comprises a hydrophilic inorganic particles, in the presence of a surface cross-linking solution containing the surface crosslinking agent of the alkylene carbonate having 2 to 5, further comprising surface cross-linked by heat-treating the hydrophobic inorganic particles are added to a base resin powder having the following contact angles can do.

Hereinafter, the production method in detail for each step.

First, different implementations of the manufacturing method includes forming a hydrogel polymer by cross-linking polymerization. Specifically, the monomer to the composition in the presence of an internal cross-linking agent comprises a water-soluble ethylenically unsaturated monomer and a polymerization initiator, a thermal polymerization or photo-polymerization to form a hydrogel polymer.

Water-soluble ethylenically saturated monomer block included in the monomer composition are as previously described.

Further, the monomer composition may include a polymerization initiator commonly used in the production of superabsorbent polymer. Non-limiting examples of the polymerization initiator include thermal polymerization initiator or a photopolymerization initiator may be used in accordance with the polymerization method. However, even in the photo polymerization method, a certain amount of heat generated by UV irradiation, and further, because a certain amount of heat generated with the progress of the polymerization reaction heat banung, may be included to add a thermal polymerization initiator.

Here, the photopolymerization initiator is, for example, benzoin ethers (benzoin ether), dialkyl acetophenones (dialkyl acetophenone), hydroxyl-alkyl ketones (hydroxyl alkylketone), phenyl glyoxylic rate (phenyl glyoxylate), benzyl dimethyl ketal (Benzyl Dimethyl ketal), acylphosphine (acyl phosphine) and alpha-wherein the at least one compound selected from the group consisting of amino-ketone (a-aminoketone) may be used. Specific examples of the acylphosphine of that, commercial lucirin TPO, i.e., 2,4,6-trimethyl-i i-trimethyl benzoyl phosphine oxide can be used pins (2,4,6-trimethyl-benzoyl-trimethyl phosphine oxide) to . Wider range of light for the polymerization initiator Reinhold Schwalm book,: is disclosed in "UV Coatings Basics, Recent Developments and New Application (Elsevier 2007 year)" of the first page 15, and can refer to it.

Further, the heat polymerization initiator and has a sulfate-based initiators, azo initiators, hydrogen peroxide, and at least one compound selected from the group consisting of ascorbic acid may be used. Specifically, the persulfate-based initiator and sodium sulfate (Sodium persulfate; Na 2 S 2 0 8 ), potassium persulfate (Potassium persulfate; K 2 S 2 0 8 ), ammonium persulfate (Ammonium persulfate; (NH 4 ) 2 s 2 0 8 are exemplified, and so on). Also,

Azo (Azo) based initiators include 2,2-azobis (2-amidinopropane) dihydrochloride (2,2-azobis (2-amidinopropane) dihydrochloride), 2,2-azobis- (Ν, Ν- dimethylene) isobutoxy Thira Mai Dean D. hydrochloric Lai -E. (2,2-azobis- (N , N-dimethylene) isobutyramidine dihydrochloride), 2- ( carbamoyl-azo) isobutyronitrile (2- (carbamoylazo) isobutylonitril ), 2,2-azobis [2- ( 2 -imidazolin- 2 -yl) propane] dihydrochloride ( 2 , 2-azobis [ 2 - ( 2 -imidazolin- 2 -yl) propane] dihydrochloride), 4,4-azobis- the like are exemplified (4-cyano ballet rigs acid) (4,4-azobis- (4- cyanovaleric acid)). Than it is disclosed in page 203 of "Principle of Polymerization (Wiley, 1981 year)" which is Odian book for various thermal polymerization initiator, and can refer to it.

The polymerization initiator may be added at a concentration of about 0.001 to 1% by weight relative to the monomer composition. That is, when the concentration of the polymerization initiator is too low and may slow the rate of polymerization is not preferable because it can be residual monomers are extracted in a large amount in the final product. On the other hand, it is not preferable because the resin properties such as the concentration of the polymerization initiator over the content of the component for the number becomes the polymer chains that make up the network shorter increased at higher pressure that water absorption capacity is reduced can be lowered.

On the other hand, the monomer composition includes a cross-linking agent ( "internal crosslinking agent") to improve the physical properties of the composition according to the polymerization of the water-soluble ethylenically unsaturated monomer. The cross-linking agent as for the internal cross-linked hydrogel polymer, can be used separately from the "surface cross-linking agent" to be described later.

Specifically, the In other implementations the manufacturing method, the internal cross-linking agent than previously described two species, for example > polyol poly (meth) acrylate-based first internal crosslinking agent, and allyl (meth) acrylate-based second with an internal cross-linking agent using, the higher gel strength, for example, 10000Pa or higher, or UOOOPa above, or 120000Pa or more, in particular limit is, but 40000Pa, alternatively no more than 30000Pa or less, or to obtain a hydrogel polymer having a gel strength of 28000Pa or less have.

More specifically, the first internal cross-linking agent is trimethylolpropane tri (meth) acrylate, ethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylates, poly propylene glycol di (meth) acrylate,

Butane diol di (meth) acrylate, butylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, acid dayieul di (meth) acrylate, triethylene glycol di (meth) acrylate, tri propylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, di-penta-erythro Li a pentaacrylate, glycerin tri (meth) acrylate and penta-erythro frame least one member selected from the group consisting of tetra-acrylate a can be used, wherein the second internal cross-linking agent is allyl methacrylate and the like can be used, or allyl acrylate.

In addition, the first and the total content of the second internal cross-linking agent may be in an amount of 0.4 part by weight to 2 parts by weight, or from 0.4 to 1.8 parts by weight based on 100 parts by weight of a monomer composition including the internal crosslinking agent and monomer . Further, the first internal cross-linking agent: a second internal cross-linking agent is from 1: can be used in a weight ratio of 1: 1 to 10. Thus, for adjusting the composition such as type and quantity range of the internal cross-linking agent other hand, as the control of water content of below hydrogel polymer, it is possible than to obtain effectively the hydrogel polymer indicates the gel strength of at least lOOOOPa, an implementation that meets the example Physical properties The superabsorbent . It can be more effectively achieved the resin. However, the larger the amount of the internal cross-linking agent is too, can be a basic absorption performance of the super-absorbent resin decreases.

In addition, the monomer composition has an additive such as a thickener, a plasticizer, a preservation stabilizer, an antioxidant can be further included if necessary.

Then, this monomer composition can be a raw material such as the above-described monomer, a polymerization initiator, an internal crosslinking agent prepared in the form of a solution dissolved in a solvent.

At this time, a usable solvent as long as it can dissolve the above-described raw materials may be used without any limitation in its configuration. For example, as the solvent is water, ethanol, ethylene glycol, diethylene glycol,. Triethylene glycol, 1,4-butanediol, propylene glycol, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, methyl ethyl ketone, acetone, methyl amyl ketone, cyclo hex rice, cyclopentanone, diethylene glycol monomethyl ether, diethylene glycol ethyl ether, the toluene, xylene, butyrolactone, a non-carboxylic, cellosolve acetate, Ν, Ν- dimethylacetamide methyl-cell, or a common compound such as

It can be used.

And, forming a hydrogel polymer by polymerization of the monomer composition can be carried out in a conventional polymerization process, the process is not particularly limited. Non-limiting examples, the polymerization process is divided into large thermal polymerization and photo polymerization according to the type of the polymerization energy source, if the progress of the thermal polymerization can be conducted in a reactor having an axis agitation, such as a kneader (kneader), a photopolymerization when proceeding to may take place in a half unggi provided with a movable conveyor belt.

For example, by putting the monomer composition in the reactor such as a kneader equipped with a stirring shaft, and a thermal polymerization by supplying hot air or heaters banung here it is possible to obtain a hydrogel polymer. In this case, the function to be discharged to the discharge port depending on the type of anti-unggi stirring shaft provided with a half unggi polymer gel can be obtained particles of a few millimeters to several centimeters. Specifically, there is a hydrogel polymer obtained can be obtained in various forms depending on the concentration and the injection rate of the monomer composition to be injected, usually (weight average) grain size of 2 to 50 mm hydrogel polymer - can be obtained. And, one another example, if the progress of photopolymerization of the monomer composition in a reactor provided with a movable conveyor belt has a hydrogel polymer in the form of a sheet can be obtained. The thickness of the sheet may vary depending on the concentration and the injection rate of the injected monomer composition, to ensure the production speed, but that the entire sheet can be uniformly polymerized, which typically lead adjusted to a thickness of 5 to 10 cm it is desirable.

The hydrogel polymer is formed in the same way 38 is increased to 58 0 may have a water content of /., Or 40 to 55% by weight. This water content may be controlled to a desired range in accordance with control of the above-described polymerization conditions. More specifically, for control of the water content, the solvent in the monomer composition is provided to the polymerization alkaline substance to adjust the amount of (e. G., Water), or used in order to neutralize the water-soluble ethylenically unsaturated monomers such as the aforementioned acrylic acid solution the concentration can be adjusted. For example, the alkali concentrations (e.g., concentration of sodium hydroxide in aqueous sodium hydroxide solution) 23 to 40 parts by weight of the of the alkaline substance solutions 0 to adjust a /., The water content of the hydrogel polymer under the above-mentioned 58% by weight It can be achieved. Here, the water content is a weight occupied by the water on the total weight of the hydrogel polymer, it may be a value obtained by subtracting the weight of the dry polymer from the weight of the hydrogel polymer. More specifically, it can be defined as a value calculated by measuring the weight decrease due to evaporation of water in the polymer in the course of drying the temperature of the polymer eulryeo via infrared heat. At this time, the drying conditions after 180 raising the temperature from room temperature to about 18 (C ° may be the total of drying time in a manner that maintains the C comprises five minutes the temperature rise step is set to 20 minutes.

Not only is the water content is adjusted to within the above ranges already described above pulverized gel before the gel strength of at least lOOOOPa of the hydrogel polymer may be achieved more effectively, it is after the gel crushing may proceed effectively. More specifically, , is added to the polymerizable hydrogel polymer is a gel-crushing device at the water content is controlled by the control state of the conditions (a chopper, and so on), the gel pulverization conditions to be described later according to the regulated, high gel strength range before the gel pulverization is able to be not only more easily be achieved, keeping the gel strength after the gel crushing of 35% to 90% of the gel strength before the cutting, or 50% to 89%, or 60% to 88%. As a result, the base resin powder and a high-spreads the internal surface area of the superabsorbent polymer comprising the same water-absorbent resin is indicating too, maintains a is the base resin powder and the super-absorbent resin high gel strength excellent absorption rate (i. E., The gel pulverization intensity ratio of before and after is adequately maintained), it is possible to exhibit such excellent liquid tube and fast absorption rate.

On the other hand, after forming a gel polymer by the above-described functions are cross-linked polymerization, the gel crushing the hydrogel polymer of the water content is controlled. This gel crushing may be carried out such that 35% to 90% of the gel before the gel strength after gimdo crushing crushed. In a specific example, the gel strength after the gel crushing may be as 7000Pa to 30000Pa, or lOOOOPa to 24000Pa, This makes may be a super-absorbent resin that meets one embodiment the physical properties obtained more effectively.

Grinder used in the gel crushing step, is limited to the configuration, but, specifically, a vertical cutter (Vertical pulverizer), turbo cutter (Turbo cutter), a turbo grinder (Turbo grinder), rotary cutting mill (Rotary cutter mill), cutting mill (cutter mill), disc mill (disc mill), a piece crusher (Shred crusher), crusher (crusher), the chopper (chopper) and source plate type cutter (selected from the crushing device group consisting of disc cutter) It can include any one, but are not limited to the above example.

On the other hand, the gel pulverization of the hydrogel polymer, there is the shear force and the compressive force applied to the hydrogel polymer action, as another embodiment method in the adjustment of these gel pulverization conditions, achieve a gel strength range after the above-described gel pulverization can do.

More specifically, the gel crushing may be carried out inside the grinder containing an extruder equipped with a perforated plate such as a screw-type extruder therein. At this time, the multi by a plurality of holes formed in the perforated plate 9 to 15mm, or 9 to have a diameter of 13mm, or from 10 to 12mm, this is through the perforated plate and the extruder may proceed to gel-pulverized pushing the hydrogel polymer. This allows, the hydrogel polymer after the gel crushing is conducted in a suitable level to maintain the gel strength, yet, the gel polymer is crushed effectively after the crushing are able to have a large surface area.

In other words, when proceeding to the grinding process described above the gel, it is the surface area of ​​the milled hydrogel polymer significantly increased. Specifically, it is in the comminuted hydrogel polymer, the ratio of the number of blood shear particles of 0.40 or more 0.95 or less. The "blood shear particle" means, a means for three or more particles having a depth of 10 or more recesses or pores observed on the comminuted hydrogel polymer particles, and the 'blood ratio of the number of shear particle "means, pulverized hydrogel It denotes the number of the to-be-shearing particles compared to the total number of polymer particles. High blood becomes shear particle is generated a wider surface area as described above, and the physical properties such as the absorption rate of the water-absorbent resin can be further improved, it is one embodiment, super-absorbent resin cheungjok the various physical properties can be produced more effectively..

On the other hand, the hydrogel of the gel polymer is pulverized, the particle size of the hydrogel polymer may be performed such that 0.1 mm to 10 mm. That is, the hydrogel polymer to an increase in drying efficiency is preferably ground to a particle of less than 10 mm. However, since a cross-over-pulverized particles during ungjip phenomenon may occur, the hydrogel polymer is preferably ground to a gel than 0.1 mm particles.

Further, the hydrogel of the gel polymer is crushed, the water content may be due to relatively low performed on the surface of a gel crusher experience the developer adhering to the polymer hydrogel. In order to minimize this phenomenon, if necessary, steam, water, surfactants, (such as, for example clay, silica) ungjip agent; Persulfate-based initiators, azo initiators, hydrogen peroxide, thermal polymerization initiator, an epoxy-based crosslinking agent, a diol (di) acids crosslinking agent, a second functional group, or 3 is a functional group or more cross-linking agent comprises an acrylate functional group, a cross-linking agent of the first functional group comprises a hydroxyl group etc. may be added to the hydrogel polymer.

After the above-described gel pulverization, it is possible to dry the hydrogel polymer. The drying may be carried out in the silver is 120 to 250 ° C, preferably from 140 to 200 ° C, more preferably 150 to 190 ° C. In this case, the drying temperature may be defined in the temperature or drying step of the thermal medium to be supplied for drying a drying temperature in the half unggi including a heat medium and a polymer. If the drying temperature is low, the drying time long, so the process efficiency is lowered, a drying temperature in order to prevent this, is preferably at least 120 ° C. On the contrary, if the drying temperature is higher than necessary, and can be dried to overly the surface of the hydrogel polymer is finely divided generated more in a grinding step subsequent step, there is the physical properties of the final resin can be reduced, the drying temperature in order to prevent this, not more than 250 ° C is preferred.

At this time, the drying time in the drying step may be not particularly limited, in consideration of the physical properties of the resin and process efficiency, adjusted to 20 minutes to 90 minutes at the drying temperature.

The drying may be done using a conventional medium, for example, may be performed through a method such as the hot air supplied to the pulverized hydrogel polymer, infrared irradiation, microwave irradiation, or UV irradiation.

In addition, such drying is that the dried polymer from about 0.1 to 10 parts by weight 0 is preferably carried out so as to have a water content of /. That is, the water content of the dry polymer coming from one weight 0 / 0 's may occur decomposition (degradation) of the rise and cross-linking of the polymer is less than the manufacturing cost due to excessive drying is not preferred. And, if the water content of the dry polymer more than 10% by weight is not preferable because it may cause the amount of block in the subsequent steps.

After the drying, it is possible to crush the dried polymer, may This allows the particle size and surface area of ​​the polymer can be adjusted to an appropriate range. The pulverization can be carried out such that the particle size of the ground polymer from 150 to 850.

At this time, by using a crusher that can be used are conventional, such as pin mill (pin mill), a hammer mill (hammer mill), screw mill (screw mill), a mill (roll mill), disc mill (disc mill), a jog mill (jog mill) that the may be used.

Further, the step of selectively classified into particles having a particle diameter of 150 to 850 卿 in the polymer particles obtained through the pulverizing step may be further carried out and that the final commercialized to manage the physical properties of the water absorbent resin.

On the other hand, after the manufacture of the base resin powder through to the above-described classifying process it can be high in the presence of a surface crosslinking agent, and heat-treating the base resin powder surface crosslinking the water absorbent resin particles. The surface cross-linking may be shown to induce a cross-linking banung on the surface of the base resin powder in the presence of a surface cross-linking agent, a surface modification layer on the surface of the base resin powder from such a surface cross-linking (surface cross-linked layer) is formed.

In more detail, the manufacturing method described above daron implemented, for water

50 ° step of adding the hydrophobic inorganic particles having the above contact angle; And 10 for water ° and the hydrophilic inorganic particles having a contact angle of less than, in the presence of a surface cross-linking solution containing the surface crosslinking agent of the alkylene carbonate having 2 to 5, for heat-treating the hydrophobic inorganic particle is added a base resin powder method may be carried out the surface cross-linking. This allows, it may be a surface cross-linked layer having a certain level of thickness uniformly formed, the super-absorbent resin, such as showing a high gel strength, and excellent liquid cylinder can be more effectively obtained.

In such a surface cross-linking process, the more appropriate example of a carbon number of 2 to 5 alkylene carbonates that can be used as the surface crosslinking agent is, ethylene carbonate, propylene carbonate or butylene may be mentioned a carbonate, and the like, for use with two or more selected among them also available as a matter of course.

At this time, the amount of the surface cross-linking agent can be appropriately can be adjusted, preferably controlled parts from 0.001 to 5 parts by weight per 100 parts by weight of the base resin powder according to the kind of the crosslinking agent or banung conditions. When the too low amount of the surface cross-linking agent, a surface modification can not be achieved properly, the physical properties of the final resin can be lowered. Conversely an excess of the surface crosslinking agent is used because of the excessive surface cross-linking reaction not preferable because the absorption capacity of the basic resin can be even reduced

not.

On the other hand, with respect to in the surface cross-linking step, use hydrophobic and / or the type of the hydrophilic inorganic particles are possible, as described already above.

Further, in the surface cross-linking process, first, the combined wave the hydrophobic inorganic particle relative to the base resin powder in a solid state may be processed on its surface, and its processing method is subject to a dry treatment and / or heunhap to common inorganic powder can. Further, also there is no particular limitation on the configuration of the surface cross-linking solution containing the hydrophilic inorganic particles and the surface cross-linking agent in the method of adding the base resin powder. For example, the surface cross-linked into a liquid and a base resin powder article banung heunhap or base method of the resin surface crosslinking aekreul spraying a powder, it was continuously supplied to a base resin powder and the surface cross-linking solution in the mixer being continuously driving a common summing You can use the methods.

Further, the hydrophobic inorganic particle, and the hydrophilic inorganic particles may be used in an amount, respectively, based on 100 parts by weight, from 0.0001 to 0.3 part by weight, or 0.001 to 0.2 parts by weight of the base resin powder. This allows, it is the whole liquid, and various characteristics of the superabsorbent polymer can be improved effectively, in accordance with the use of each of the inorganic particles. Examples of an implementation produced using each of the inorganic particles in such amount that the water absorbent resin may also comprise a hydrophobic and a hydrophilic inorganic particle content in a range equivalent thereto.

The surface cross-linking solution may further include water and / or hydrophilic organic solvent as a medium. This allows, the surface cross-linking agent and a hydrophilic inorganic particle has an advantage that can be uniformly dispersed in the base resin powder. At this time, the water and the content of the hydrophilic organic solvent is a surface cross-linking agent and a hydrophilic inducing the uniform dispersion of the inorganic particles and 100 base resin powder for the purpose of optimizing the surface depth of penetration of the surface cross-linking agent and at the same time preventing the aggregation phenomenon of the base resin powder weight It can be applied by adjusting the addition ratio of the unit.

The surface cross-linking solution is 140 for the addition of a base resin powder ° C to 200 ° C, or 170 ° C to 195 ° 5 to 60 minutes in the reaction up to a temperature of C, or 10 minutes to 50 minutes, or 20 minutes to for 45 minutes it may be carried out a surface crosslinking banung. More specifically, the surface cross-linking step is 20 ° C to 130 ° C, or 40 ° and the temperature was raised to C to from the initial temperature of 120 ° C 10 min or more, or 10 minutes to 30 minutes the banung maximum temperature throughout, by annealing by holding the maximum temperature for 5 minutes to 60 minutes it may be done.

These surface cross-linking process conditions superabsorbent resin to properly meet one embodiment the physical properties by cheungjok (in particular, an elevated temperature conditions and reaction conditions at the maximum temperature banung) can be prepared more effectively.

Temperature raising means for the surface cross-linking reaction is not particularly limited. Supplying a heating medium, or can be heated to supply the heat source directly. At this time, as a type of available heating medium, but can use a fluid such as an elevated temperature, such as steam, hot air, hot oil, not limited to this, and the temperature of the heating medium to be supplied is the means, the rate of rise and temperature rise target temperature of the heating medium It can be appropriately selected in consideration. On the other hand, as a heat source is directly supplied to the heating by electricity, but include a method of heating with a gas, it is not limited to the above example.

The super-absorbent resin obtained by the above production method is beam and SAT and maintained excellent absorption performance, such as pressure absorption capacity, than to meet the enhanced tube-component and the rate of absorption, etc., may suffice with one embodiment various physical properties of layers, a diaper, such as sanitary materials, in particular, the content of the pulp decreases ultra-thin sanitary material or the like can be used as appropriate.

【Effects of the Invention】

Super-absorbent resin according to the present invention, yet can excellently maintain the basic ability to absorb, and can exhibit such improved absorption rate and the barrel-component, it can be preferably applied to the diaper such as sanitary material having a thinner thickness.

[Mode for Carrying out the invention]

Below, it is presented to a preferred embodiment for better understanding of the invention. However, it the practice of the following examples is not intended to limit to these a may make the present invention to illustrate the present invention.

In the Examples and Comparative Examples, the contact angle against water of a hydrophobic inorganic particle, and the hydrophilic inorganic particles was measured as follows.

First, the hydrophobic inorganic particle is dispersed in a coating solution in which methylene chloride was used as the solvent at a concentration of 5% by weight. After spin-coating this coating solution on the wafer without any surface roughness of the solvent remaining was dried at room temperature was to be removed. Dropped into the water dropwise onto this coating layer was measured for contact angle. Thus the contact angle measured by defining a contact angle with water of the hydrophobic inorganic particles are shown in Table 1 below for the measurement.

In the case of hydrophilic inorganic particles, 20 parts by weight 0 and it is, in the same way as the hydrophobic inorganic particle to measure the contact angle for water are shown in Table 1, except at a concentration of /. Was used to form the dissolved or dispersed in the coating solution in water .

TABLE 1

Example 1

And a device for manufacturing a water-absorbent resin is the polymerization process, hydrogel milling step, a drying step, grinding balls , tablets, the classification step, the surface cross-linking step, nyaenggak step, the classification step, and continuous production apparatus consisting of a transport step of connecting the respective steps It was used.

(Step 1)

Acrylic acid 100 parts by weight as an internal crosslinking agent in the unit of polyethylene glycol diacrylate (weight-average molecular weight: ~ 500 g / mol) and the combined allyl methacrylate common to prepare a monomer solution IRGACURE 819 0.01 The combined common parts by weight to 0.4 parts by weight of photoinitiator It was. Then, the monomer solution was continuously fed to the metering pump, while, at the same time to prepare a continuous line mixing to the monomer aqueous solution of 24 weight parts 160 weight% aqueous solution of sodium hydroxide. At this time the temperature rises by junghwayeol 40 ° was adjusted to C. Further, after that generated 4 wt% sodium persulfate aqueous solution 6 parts by weight of a continuous line mixer, was continuously fed to the continuous polymerization with the polymerizable groups on the belt having a dam on one plane at both ends. After UV irradiation for 1 minute, and subjected to heat polymerization by 2-minute while to prepare a hydrogel. The water content of such hydrogel was identified as 45% by weight.

(Step 2)

After the hydrogel was cut with an average size is less than or equal to about 300 mm, put into a pulverizer (which is provided with a perforated plate comprising a plurality of holes having a diameter of 10mm), which was triturated with each condition.

(Step 3)

It was then drying the hydrogel pulverized in the above step 2 at a flow rate as possible transition to the upper and lower dryer. The water content of the dry powder 180 is less than or equal to about 2% ° to the flow from the lower side while the air (hot air) hot for C 15 minutes, and the upper and flows downwardly in the back above for 15 minutes, even the hydrogel drying It was.

(Step 4)

Crushing the dried resin from step 3 to a mill and then classified to 150 to 850 / zm to obtain a base resin of the size.

(Step 5)

Then, for a base resin prepared with 100 parts by weight of the base resin powder prepared as described in Step 4, and the hydrophobic silica particles of DM30S into parts of 0.05 wt blend well stirred to a base resin powder and hydrophobic silica particles at room temperature Messenger common combined was dry-process . Then, lg of ethylene carbonate, the concentration of a hydrophilic silica particles (ST-0) of a 20% by weight is put into the aqueous solution of 0.2g is dispersed in water in a water 3g common combined to prepare a surface cross-linking solution. Then, the injection liquid in the surface cross-linked base resin powder and the mixture was stirred at room temperature was heunhap to the surface cross-linking solution evenly distributed in the base resin powder. Then, into a base resin powder heunhap the surface cross-linking solution on the surface cross-linking reactor and proceed to the surface cross-linked banung.

Within this surface cross-linking reactor, a base resin powder is 80 ° 190 later was found to be gradually raised from the initial temperature in the vicinity of C, 30 minutes, ° was operated to reach a maximum temperature of banung C. After reaching such maximum temperature banung, the superabsorbent polymer sample was added to the final production reaction for 15 minutes

It was taken. Embodiment having the above surface cross-linking step and then, by classifying the particle diameter of the sieve mesh standard ASTM specifications 150 to 850 / m to prepare a super-absorbent resin of Example 1.

Example 2

Cross-linking agent into the polyethylene glycol diacrylate (average molecular weight: -

500 g / mol) and allyl methacrylate were combined common to prepare a super-absorbent resin of Example 2 in the same manner as in Example 1 except that 0.55 parts by weight.

Example 3

And: the cross-linking agent into the polyethylene glycol diacrylate (~ 500 g / tnol weight average molecular weight). Allyl using methacrylate common combined parts of 0.55 by weight, carried out in the same manner as in Example 1, except that adjusting the concentration of sodium hydroxide in aqueous solution of sodium hydroxide to adjust the water content of the hydrogel to 50 wt% of Example 3 and to prepare a water-absorbent resin.

Example 4

As an internal crosslinking agent Polyethylene glycol diacrylate (weight-average molecular weight: ~ 500 g / mol) and a super-absorbent resin of the embodiment in the same manner as in Example 1 except that the allyl methacrylate common combined parts of 0.75 wt Example 4 It was prepared.

Example 5

As an internal crosslinking agent Polyethylene glycol diacrylate (weight-average molecular weight: ~ 500 g / mol) and using allyl methacrylate common combined parts of 0.75 by weight, and adjusting the concentration of sodium hydroxide in aqueous solution of sodium hydroxide to the water content of the hydrogel 50 parts by weight 0 , except that a control to /. to prepare a super-absorbent resin of example 5 in the same manner as in example 1.

Example 6

As an internal crosslinking agent Polyethylene glycol diacrylate (weight-average molecular weight: ~ 500 g / mol) and using allyl methacrylate common combined parts of 0.75 by weight, and adjusting the concentration of sodium hydroxide in aqueous solution of sodium hydroxide to the water content of the hydrogel 55 parts by weight 0 / 0 was to manufacture a super-absorbent resin of example 3 in the same manner as in example 1, except that a control.

Comparative Example 1

In step 2, in the example, except after the hydrogel was cut with an average size is less than or equal to about 300 mm, that the input to the grinder (which is provided with a perforated plate comprising a plurality of holes having a diameter of 16mm) and milled 1 and was prepared in the super-absorbent resin of Comparative example 1 in the same manner.

Comparative Example 2

Into the cross-linking agent in step 1 of polyethylene glycol diacrylate (weight-average molecular weight: ~ 500 g / mol) and using allyl methacrylate common combined parts of 0.55 by weight, and adjusting the concentration of sodium hydroxide in aqueous sodium hydroxide solution and hydrogel the water content in the was adjusted to 50% by weight, in step 2, after the hydrogel was cut with an average size is less than or equal to about 300 mm, grinder (which is provided with a perforated plate comprising a plurality of holes having a diameter of 16mm) in except that the milling was producing a super-absorbent resin of Comparative example 2 in the same manner as in example 1.

Comparative Example 3

Acrylate polyethylene glycol di acrylate in step 1, and an internal crosslinking agent (weight-average molecular weight: ~ 500 g / mol) of the allyl meth comparison in the same manner as in Example 1, common combined methacrylate except that parts of 0.35 increase Example 3 and to prepare a water-absorbent resin.

Comparative Example 4

Into the cross-linking agent in step 1 of polyethylene glycol diacrylate (weight-average molecular weight: ~ 500 g / mol) and using allyl methacrylate common combined parts of 0.75 by weight, and adjusting the concentration of sodium hydroxide in aqueous sodium hydroxide solution and hydrogel a water content of 60 weight 0 / 0 was prepared in the super-absorbent resin of Comparative example in the same manner as in example 1, but was adjusted to 4.

Comparative Example 5

A super-absorbent resin of the hydrophobic silica particles and, in Example compared in the same manner as in Example 45 except for not using an aqueous solution of the hydrophilic silica particles was prepared in step 5.

In the above Examples 1-6 and Comparative Examples] to 5, and the gel strength of the hydrogel of the gel before and after the pulverization was measured using the methods summarized in the following, the measurement results are shown collectively in Table 2 below.

* How the gel strength of the hydrogel measured

A. Preparation of a measurement target sample method:

First, the diameter of the measurement object hydrogel (gel before pulverized hydrogel sheet and the gel after the crushing hydrogel) were prepared in about 2 ~ 5mm size: about 2.5cm, a thickness. 180: the prepared samples loaded into a microbalance and, using the spray was evenly spray the appropriate amount of distilled water (this time, by measuring the initial water content of the hydrogel in advance (water content measuring conditions ° match C, 40 minutes) to the initial water content It computes the amount of water needed.). In order to uniformly adjust the water content of the sample inside, sealed in plastic and stored at room temperature over 12 hours.

B. How to measure:

Loading the hydrogel sample of the water content is adjusted between two plates of a rheometer (ARES-G2), and the gap was set to urge the two plates with a force of 3N such that the sample is in contact all on the front of the plate. Rest Time was given to stabilizing the sample for 5 minutes. Increasing the strain in the first 10 rad / s frequency of the measurement is confirmed that Strain constant Linear Viscoelastic Regime interval Storage Modulus (G ') and the Loss Modulus (G ").

Find the Strain value (usually 0.1%) of Linear Regime interval, a constant

In the frequency 10 rad / s) for 60 s, was measured, G "). After the measurement three times or more, G 'viscoelasticity (G was calculated as the average value of the gel strength (G')

TABLE 2

Referring to Table 2, Examples 1 to 6 are adjusted such as internal cross-linking agent content, water content, gel pulverization before hydrogel this has a gel strength of at least lOOOOPa, the gel is such as perforated plate hole diameter and water content of a gel crusher is adjusted to the pulverized gel strength cheungjok the range of 35 to 90% prior to the gel breaking. In Examples 1 to 6 was conducted for the surface cross-linking step using a predetermined inorganic particles and two kinds. Alkylene carbonate surface crosslinking agent.

On the other hand, Comparative Examples 1 and 2 is of a gel crusher this stencil hole diameter suitable

Range the outside it will gel strength of the layer can not jokhaji the range of 35 to 90% before the gel pulverization after the gel crushing, Comparative Example 3 is the total content of the range of internal cross-linking agent is outside the proper range a gel strength of less than the gel pulverization before hydrogel lOOOOPa the one having. Further, in Comparative Example 4 will water content is outside the proper range a gel strength after the gel crushing does jokhaji layer the range of 35 to 90% before the gel crushing, Comparative Example 5 is not used two kinds predetermined inorganic particles in the surface cross-linked .

Experimental Example

Subjected to a physical property of each super-absorbent resin prepared in Examples and Comparative Examples were measured and evaluated in the following manner.

(1) particle size evaluation

Exemplary diameter of the base resin powder and a super-absorbent resin used in the Examples and Comparative Examples were measured according to the European Nonwoven Industry Association (European Disposables and Nonwovens Association, EDANA) standard method EDANA WSP 220.3.

(2) centrifuging beam SAT (CRC, Centrifuge Retention Capacity)

A centrifuge beam SAT (CRC) due to no load jeungha absorption ratio was determined according to European Nonwoven Industry Association (European Disposables and Nonwovens Association, EDANA ) standard EDANA WSP 241.3. Superabsorbent Polymer W 0 (g, about 0.2g) after the insert uniformly in the envelope of the nonwoven fabric is sealed (seal), was submerged in the saline solution of sodium chloride solution of 0.9 weight% at room temperature. After 30 minutes using a centrifuge, and the weight of the envelope bag W for 3 minutes after removing moisture with 250G 2 it was measured (g) ol. Further, after the same operation and without using the water-absorbent resin were measured by mass Wi (g) at that time. In this way use of the respective mass obtained by the following equation 1 to calculate the CRC (g / g) it was confirmed beam SAT.

[Equation 1]

CRC(g/g) = {[W2(g) - W,(g) - Wo(g)]/W0(g)}

(3) absorption capacity under pressure (under Absorbing Pressure, AUP)

Examples and Comparative Examples that, the European Association for the nonwoven industry in the water-absorbent resin according to the process of the absorption capacity under pressure (European Disposables and Nonwovens Association) standard EDANA WSP 242.3: a (AUP Absorbency under Pressure) was measured.

First, the bottom of the cylinder having an inner diameter of 60 mm plastic was fitted to a stainless steel 400 mesh wire net. 23土2 ° in temperature and 45% of the C embodiments the iron mesh under a relative humidity Example Resin 1 and obtained in the 6 and Comparative Examples 1 to 3 W 0 (g, 0.90 g) to uniformly spray and 4.83 kPa thereon ( 0.7 psi) the piston (piston) that can be more uniformly impart load was not the outer diameter is slightly smaller and there is no break in the inner wall of the cylinder than 60 mm, the upper and lower motion undisturbed. The weight W of the device 3 was measured (g).

With a glass filter having a thickness of 5 mm on the inside of the Petro-dish with a diameter of 150 mm in diameter 125 mm, a saline solution consisting of 0.90 wt% sodium chloride it was adjusted to the same level as the upper surface of the glass filter. On top of the filter paper having a diameter of 120 mm

The room was one. Carrying the measurement device over a filter paper, the solution was absorbed for 1 hour under a load. After 1 hour, lift the measuring device, the weight W 4 was determined (g). ■

In this way use of the respective mass obtained by the following equation 2 to calculate the AUP (g / g) confirmed that the pressure absorbing ability.

[Formula 2]

AUP (g / g) = [W 4 (g) - W 3 (g)] / W 0 (g)

In the formula 2,

W 0 (g) is the initial weight (g) of the superabsorbent resin,

W 3 (g) is a total weight of the device being capable of imparting the weight and the load on the super-absorbent resin having a high water-absorbent resin,

W 4 (g) is a total sum of the unit weight which can impart a load to the weight and the high water-absorbent resin for one hour and the water absorbent resin after the high absorption of saline solution to the water-absorbent resin, while under load (0.7 psi).

(4) Gel strength (Gel Strength; G ')

Examples and Comparative Examples and the water absorbent resin with respect to the horizontal direction of the gel strength (Gel

The Strength) was measured.

First, Examples and Comparative Examples and the water absorbent resin sample (30 - 50 Mesh) were weighed every other 0.5g body a. The weighed sample was fully swollen with physiological saline for one hour 50 g. Thereafter, the solvent is not absorbed is removed by using an aspirator for 4 minutes, and the solvent adhering to the surface is evenly distributed by the filter paper served wiping once. The swollen water-absorbent resin and place the sample between 2.5g rheometer (R eometer) with two parallel plates (in the wall of diameter 25mm, so the lower the sample of about 2mm escape), the distance between the two parallel plates It was adjusted to 1mm. At this time, by pressing with a force of approximately 3N was adjusted to a distance between the parallel plates so as to contact both in parallel to the swollen superabsorbent polymer sample plate surface.

In Oscilation frequency of 10 rad / s using the rheometer, while increasing the shear strain, stored tanseongreul (storage modulus) and a loss elastic modulus (loss modulus) The shear deformation of the constant-wise linear viscoelastic conditions (linear viscoelastic regime) confirmed. In general, the swelling superabsorbent resin as a sample, the shear strain of 0.1% is within the linear viscoelastic state interval.

At a constant 10 rad / s of Oscilation frequency, the linear viscoelastic region the gohop state were measured for storage modulus and loss modulus of the water-based resin it swelled for 60 seconds shear value. At this time, by taking the average of values ​​obtained the storage modulus was determined a horizontal gel strength. For reference, the loss elastic modulus is measured according to the very small value compared to the storage modulus.

(5) flow-induced physiological saline (SFC; saline flow conductivity)

United States was measured and calculated according to the method disclosed in Patent No. 5,562,646 the arc column 54 to column 59.

(6) 30 superabsorbent speed

- 30 seconds is the absorption rate and porosity while swelling under 0.3psi pressure condition by a super-absorbent resin of from about 0.16g to a physiological saline flows through the mesh of the cylindrical cylinder bottom can be measured. And that in real time, measure the variation in height of the top plate rheometer according to the volume expansion of the water-absorbent resin, the top plate of 30 seconds

It can be measured and calculated the rate of absorption the 30 seconds with a value obtained by dividing the height in the absorption time (30 seconds). Further, the void ratio is the high time would have been the swelling of the water-absorbent resin completed, and calculates the total volume of the inner cylinder (end absorption height * cylindrical cylinder lower area), subtracting a physiological saline absorption of the superabsorbent resin measured at the value to the water content meter It can be calculated by the method.

(7) FSR (Free Swell Rate)

And FSR of the water-absorbent resin was measured and calculated by the method described in European Patent Publication No. 2535027 call page page 22 to 23.

To the respective physical properties of the measurement carried out using the above Examples 1-6 and Comparative Examples 1-5 are shown collectively in Table 3 below.

TABLE 3

Referring to Table 3, Examples 1 to 6 are the basic absorbent absorbency performance as well as excellent, which is defined as including, while excellent in liquid tube, defined as SFC, exhibits a certain level of porosity of the absorption 30 sec. I t absorption rate as defined by the slow FSR has also been found to be excellent.

On the other hand, the Comparative Examples 1 to 5 is bahae the embodiment, barrel-component or one or more of rate of absorption was found to be poor.

Claims

Water-soluble ethylenic base resin including a first cross-linked polymer of an unsaturated monomer powder having an at least partially neutralized acid; And

A super-absorbent resin to the first cross-linked polymer is formed on the base resin powder, a cross-linked layer includes a surface that includes an additional cross-linked second cross-linked polymer as a medium of an alkylene carbonate having 2 to 5,

An absorbency of from 45 to 65g / g represented by the following formula 1,

Saline solution (0.685 parts by weight 0 / sodium chloride aqueous solution.) Inductive flow; (SFC. 10 · 7 cm 3 s / g) of 40 to 180 (10. -7 cm 3. , And s / g),

30 seconds absorption rate for physiological saline solution under pressure of 0.3 psi is more than 1.5mm / min, and the water-absorbent resin having a porosity of 20% or more:

[Equation 1]

Absorbency = CRC + AUP

In the formula 1,

The CRC and the physiological saline (0.9 parts by weight of a water-absorbent resin 0 represents the beam SAT centrifugation for 30 minutes on /. Aqueous sodium chloride solution),

AUP represents the high absorption capacity of the pressure for one hour under a 0.7psi for physiological saline (0.9 wt% aqueous sodium chloride solution) of a water-absorbent resin.

[Claim 2]

According to claim 1, according to claim 1, and dispersed in said base resin powder, 50 for water ° hydrophobic inorganic particle having the above contact angle and 10 for a water ° of hydrophilic inorganic particles having a contact angle of less than superabsorbent polymer further comprises.

[Claim 3]

The method of claim 2, wherein the hydrophobic inorganic particle include silica particles, titania particles and comprising at least one element selected from the group consisting of zirconia particles and the hydrophilic inorganic particles are silica particles, titania particles, zirconia particles,

And a superabsorbent polymer containing at least one selected from the group consisting of laponite particles.

[Claim 4]

The method of claim 1, wherein the CRC is 24 to 35 g / g of superabsorbent polymer.

[5.]

The method of claim 1, wherein the AUP is 22 to 28 g / g of superabsorbent polymer.

[6.]

According to claim 1 wherein said high for one hour on a water-absorbent resin saline solution (0.9 weight 0 / a. Sodium chloride solution), after swelling by absorbing, a horizontal gel strength (G ') measured by a rheometer 8500 18000Pa to the superabsorbent resin.

[7.]

The method of claim 1 wherein the superabsorbent polymer is 1 g when the rate of absorption of 0.9 g 20% ​​by weight aqueous solution of sodium chloride (FSR, free Swell Rate) is 0.30 g / g / s or more super-absorbent resin.

[8.]

The method of claim 1, wherein the water-soluble ethylenically saturated monomer is one block ethane sulfonic acid, acrylic acid, methacrylic acid, maleic anhydride, fumaric acid, crotonic acid, itaconic acid, one ethanesulfonic acid, 2-methacryloyloxyethyl 2-acrylic, 2 - (meth) acid, or 2- (meth) acrylamide-2-methyl anionic monomers and their salts of the sulfonic acid with an acrylic; (Meth) acrylamide, N- substituted (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, methoxy polyethylene glycol, hydroxyethyl (meth) acrylate or polyethylene glycol ( meth) non-ionic hydrophilic monomers containing acrylate; And (Ν, Ν), - dimethylaminoethyl (meth) acrylate or (Ν, Ν) - dimethylaminopropyl (meth) group of acrylamide , containing unsaturated monomers and their quaternary cargo; at least one selected from the group consisting of superabsorbent polymer comprising a.

[9.]

Water-soluble ethylenic base resin including a first cross-linked polymer of an unsaturated monomer having a powder at least partially neutralizing the acid; And

A super-absorbent resin to the first cross-linked polymer is formed on the base resin powder, a cross-linked layer includes a surface that includes an additional cross-linked second cross-linked polymer as a medium of an alkylene carbonate having 2 to 5,

An absorbency of from 45 to 65g / g represented by the following formula 1,

Saline induced flow (0.685 wt% aqueous sodium chloride solution) (SFC; 10 '

W. s / g) of 48 to 180 (. 10 7 cm 3 and 's / g),

30 seconds absorption rate for physiological saline solution under pressure of 0.3 psi of 1.5mm / min to 3.0mm / min and a water-absorbent resin:

[Equation 1]

Absorbency = CRC + AUP

In the formula 1,

CRC is the high denotes a beam SAT centrifugation for 30 min on saline (0.9 wt% aqueous sodium chloride solution) of a water-absorbent resin,

AUP is physiological saline solution (0.9 parts by weight of said superabsorbent resin 0 / 0 indicates the absorption capacity of the pressure for one hour under a 0.7psi to the aqueous sodium chloride solution).

[10.]

It includes a first cross-linked polymer in the presence of an internal cross-linking agent, by cross-linking polymerization of the water-soluble ethylenically unsaturated monomer having at least some of the neutralizing acid, and the gel strength of at least git lOOOOPa; is forming a hydrogel polymer;

The method comprising the gel strength after the grinding function of the gel polymer gel to be ground to a 35% to 90% of the gel strength before the cutting;

The gel is comminuted function drying the polymer gel, thereby forming a crushing and classifying to a base resin powder;

50 for the water on the base resin powder ° step of adding the hydrophobic inorganic particles having the above contact angle; And

Hydrophilic inorganic particles having a contact angle of less than 10 ° against water and, in the presence of a surface cross-linking solution containing the surface crosslinking agent of the alkylene carbonate having 2 to 5, the surface of heat-treating the hydrophobic inorganic particle is added a base resin powder method for manufacturing a superabsorbent polymer comprising the step of cross-linking.

[Claim 1 1]

The method of claim 10, wherein said internal cross-linking agent comprises a poly (meth) acrylate-based first internal crosslinking agent, and allyl (meth) acrylate-based second internal cross-linking agent of a polyol,

The first and the total content of the second internal cross-linking agent is a process for producing a superabsorbent resin in an amount of 0.4 part by weight to 2 parts by weight based on 100 parts by weight of monomer ancestor of water including the internal crosslinking agent and monomer.

[12.]

11. The method of claim 10, wherein in the gel pulverization step, the hydrogel polymer is 38 to 58 parts by weight 0 has a water content of /., The hydrogel through the extruder equipped with a perforated plate having a plurality of holes having a diameter of 9 to 15mm method for producing a superabsorbent resin to gel crush the polymer.

[13.]

The method of claim 10, wherein the method for manufacturing a super-absorbent resin to be in the pulverizing and classifying steps, a base resin powder having a particle diameter of 150 to 850 / m is formed.

[14.]

The method of claim 10 wherein the hydrophobic inorganic particle is a silica particle, titania particle, and contains at least one element selected from the group consisting of zirconia particles and the hydrophilic inorganic particles are silica particles, titania particles, zirconia particles, and laponite particles method for producing a superabsorbent polymer containing at least one selected from the group consisting of.

[15.]

11. The method of claim 10, wherein the surface cross-linking step is 20 ° C to 130 ° C 140 over a period of 10 minutes to 30 minutes at an initial temperature in ° C to 200 ° and the temperature was raised to a maximum temperature of C, to 5 minutes for the highest temperature for 60 minutes to process for producing a superabsorbent polymer which is conducted by the heat treatment.