KR20220007341A - Method for preparing super absorbent polymer - Google Patents

Abstract

The present invention provides a method for preparing a super absorbent polymer, which increases polymerization rate by increasing the dispersibility of an antibacterial monomer when preparing a super absorbent polymer using the antibacterial monomer, induces a uniform polymerization reaction and, as a result, maintains excellent basic absorption properties such as water holding capacity and pressure absorption capacity, and can produce a super absorbent polymer uniformly exhibiting excellent bacterial growth inhibitory properties and deodorizing properties for a long time.

Description

Manufacturing method of super absorbent polymer {METHOD FOR PREPARING SUPER ABSORBENT POLYMER}

The present invention increases the polymerization rate by increasing the dispersion of the antibacterial monomer in the preparation of the superabsorbent polymer using the antibacterial monomer, induces a uniform polymerization reaction, and as a result, while maintaining excellent basic absorption characteristics such as water holding capacity and absorbency under pressure , to a method for producing a superabsorbent polymer capable of producing a superabsorbent polymer uniformly exhibiting excellent bacterial growth inhibitory properties and deodorizing properties for a long period of time.

Super Absorbent Polymer (SAP) is a synthetic polymer material that can absorb water 500 to 1,000 times its own weight. Material), etc., are named differently. The superabsorbent polymer as described above began to be put to practical use as a sanitary tool, and now, in addition to hygiene products such as paper diapers for children, a soil repair agent for gardening, a water-retaining material for civil engineering and construction, a sheet for seedlings, a freshness maintenance agent in the food distribution field, and It is widely used in materials such as poultices and in the field of electrical insulation.

However, the superabsorbent polymer is most widely applied to hygiene products such as children's paper diapers and adult diapers or disposable absorbent products. Among them, when applied to adult diapers, secondary odors caused by bacterial growth cause a problem that causes discomfort to consumers. In order to solve this problem, attempts have been made to introduce various bacteria growth inhibitory ingredients, deodorant or antibacterial functional ingredients such as superabsorbent polymers from the past.

However, when introducing an antibacterial agent that inhibits bacterial growth, etc., into the superabsorbent polymer, it is harmless to the human body and satisfies the economic feasibility while exhibiting excellent bacterial growth inhibiting properties and deodorizing properties. It was not so easy to select and introduce an antimicrobial component that does not degrade.

As an example, an attempt has been made to introduce an antimicrobial component containing an antibacterial metal ion such as silver, copper, zinc, etc. into a superabsorbent polymer, such as copper oxide. Such antibacterial metal ion-containing components can impart deodorizing properties by destroying the cell walls of microorganisms such as bacteria and killing bacteria having enzymes that may cause bad odors in the superabsorbent polymer. However, in the case of the metal ion-containing component, it is classified as a biocide material that can kill even microorganisms beneficial to the human body. As a result, when the superabsorbent polymer is applied to hygiene products such as diapers for children or adults, introduction of the metal ion-containing antimicrobial component is excluded as much as possible.

On the other hand, in the prior art, when introducing the antibacterial agent that inhibits the growth of bacteria, etc. into the superabsorbent polymer, a method of blending a small amount of the antibacterial agent into the superabsorbent polymer was mainly applied. However, when such a blending method is applied, it is true that it is difficult to uniformly maintain the bacterial growth inhibitory properties over time. Moreover, in the case of this blending method, in the process of mixing the superabsorbent polymer and the antibacterial agent, non-uniform applicability and detachment of the antibacterial agent may result, and there were also disadvantages such as the need to install a new facility for the blending. .

Accordingly, there is a continuous demand for the development of a superabsorbent polymer-related technology capable of exhibiting excellent bacterial growth inhibitory properties and deodorizing properties without degrading the basic absorption properties of the superabsorbent polymer.

Accordingly, the present invention increases the dispersibility of the antibacterial monomer in the preparation of the superabsorbent polymer using the antibacterial monomer to increase the polymerization rate, induce a uniform polymerization reaction, and as a result, maintain excellent basic absorption characteristics such as water holding capacity and absorbency under pressure. It is an object of the present invention to provide a method for producing a superabsorbent polymer, which can produce a superabsorbent polymer uniformly exhibiting excellent bacterial growth inhibitory properties and deodorizing properties over a long period of time.

In addition, the present invention is to provide a superabsorbent polymer manufactured by the above manufacturing method, which uniformly exhibits excellent bacterial growth inhibitory properties and deodorant properties for a long time, and also maintains excellent basic absorption properties, and hygiene products including the same .

According to one embodiment of the present invention, a water-soluble ethylenically unsaturated monomer containing an acidic group and at least partially neutralized with an acidic group is cross-linked and polymerized in the presence of a polymerizable antibacterial monomer, a surfactant and an internal crosslinking agent to obtain a hydrogel polymer. forming;

drying, pulverizing and classifying the hydrogel polymer to form a base resin powder; and

In the presence of a surface crosslinking agent, heat treatment of the base resin powder comprises the step of further crosslinking,

The polymerizable antibacterial monomer is a terpene-based compound containing an ethylenically unsaturated functional group,

The surfactant, polypropylene oxide (poly (propylene oxide); PPO) block and polyethylene oxide (poly (ethylene oxide); PEO) block copolymer comprising at least one block, respectively; And polyethylene oxide (poly (ethylene oxide); PEO) an ethoxylated aliphatic alcohol-based compound comprising a block; It provides a method for preparing a super absorbent polymer, comprising at least one of them.

According to another embodiment of the present invention, there is provided a superabsorbent polymer prepared by the above manufacturing method.

Furthermore, according to another embodiment of the present invention, there is provided a hygiene product comprising the above-described super absorbent polymer.

According to the manufacturing method of the present invention, when the superabsorbent polymer is prepared using the antibacterial monomer, the dispersion of the antibacterial monomer is increased to increase the polymerization rate, induce a uniform polymerization reaction, and as a result, excellent bacterial growth inhibitory properties and deodorizing properties It is possible to prepare a superabsorbent polymer that shows uniformly over a long period of time. In addition, the super absorbent polymer produced by the above manufacturing method can maintain excellent water holding capacity and absorbency under pressure without deterioration of physical properties due to the addition of a separate antibacterial agent by crosslinking and polymerizing the ethylenically unsaturated monomer and the antibacterial monomer when the base resin powder is formed. have. Therefore, the superabsorbent polymer can be very preferably applied to various hygiene products such as adult diapers.

Figure 1a is sample no. for the monomer composition in Test Example 1. It is a photograph observed immediately after the surfactants of 1 to 7 were added (in FIG. 1a, in vitro substrates 1 to 7 refer to sample Nos. 1 to 7, respectively).
Figure 1b is sample no. for the monomer composition in Test Example 1. It is a photograph observing the change of the monomer composition 1 hour after adding the surfactants of 1 to 7 (in FIG. 1b, test tube substrates 1 to 7 refer to sample Nos. 1 to 7, respectively).
Figure 1c is sample no. for the monomer composition in Test Example 1. This is a picture of the monomer composition observed after one hour after adding the surfactants of 8 to 11 (in FIG. 1c, the test tube substrate I is sample no. 8, B is sample no. 9, L is sample no. 10, T means sample no. 11).

The terminology used herein is used to describe exemplary embodiments only, and is not intended to limit the invention. The singular expression includes the plural expression unless the context clearly dictates otherwise. In this specification, terms such as "comprises", "comprising" or "have" are intended to designate the presence of an embodied feature, step, element, or a combination thereof, but one or more other features or steps; It should be understood that the possibility of the presence or addition of components, or combinations thereof, is not precluded in advance.

Further, in the present invention, the alkyl having 1 to 20 carbon atoms may be a straight-chain, branched or cyclic alkyl group. Specifically, the alkyl group having 1 to 20 carbon atoms is a straight chain alkyl group having 1 to 18 carbon atoms; a C1-C10 straight-chain alkyl group; a straight-chain alkyl group having 1 to 5 carbon atoms; a branched or cyclic alkyl group having 3 to 20 carbon atoms; a branched or cyclic alkyl group having 3 to 18 carbon atoms; Or it may be a branched or cyclic alkyl group having 3 to 10 carbon atoms. Specific examples include methyl group, ethyl group, n-propyl group, iso-propyl group, n-butyl group, iso-butyl group, tert-butyl group, n-pentyl group, iso-pentyl group, neo-pentyl group or cyclohexyl group and the like, but is not limited thereto.

Since the invention can have various changes and can have various forms, specific embodiments are illustrated and described in detail below. However, this is not intended to limit the invention to the specific disclosed form, it should be understood to include all modifications, equivalents and substitutes included in the spirit and scope of the invention.

In the present invention, the term "block" refers to a structural unit (or repeating unit) included repeatedly in one or more compounds or polymers.

Hereinafter, a method for producing a super absorbent polymer according to a specific embodiment of the present invention, a super absorbent polymer prepared according to the method, and hygiene products including the same will be described in more detail below.

Recently, as a method for imparting antibacterial properties to a superabsorbent polymer, a method of polymerization using a polymerizable antibacterial monomer mixed in a monomer composition is being studied when preparing the superabsorbent polymer. However, among the polymerizable antibacterial monomers, since the terpene-based antibacterial monomer has hydrophobicity, it was non-uniformly dispersed and mixed when added to the monomer composition. As a result, there is a problem in that there is a problem that there is a difference between the superabsorbent polymer products manufactured due to different reaction rates with acrylic acid, which is the main raw material of the superabsorbent polymer.

In contrast, in the present invention, a surfactant optimized for the hydrophobic antibacterial monomer is added to the monomer composition for preparing a superabsorbent polymer to uniformly disperse the hydrophobic antibacterial monomer, thereby increasing the polymerization rate, inducing a uniform polymerization reaction, and as a result, water retention capacity. And it is possible to prepare a superabsorbent polymer that maintains excellent basic absorption properties such as absorbency under pressure and uniformly exhibits excellent bacterial growth inhibitory properties and deodorizing properties for a long period of time.

Specifically, the method for producing a super absorbent polymer according to an embodiment of the present invention comprises:

forming a hydrogel polymer by cross-linking a water-soluble ethylenically unsaturated monomer containing an acidic group and at least partially neutralized with a polymerizable antibacterial monomer, a surfactant, and an internal crosslinking agent (step 1);

drying, pulverizing and classifying the hydrogel polymer to form a base resin powder (step 2); and

In the presence of a surface cross-linking agent, heat-treating the base resin powder to further cross-link (step 3);

The polymerizable antibacterial monomer is a terpene-based compound containing an ethylenically unsaturated functional group,

The surfactant, a block copolymer comprising at least one PPO block and one or more PEO blocks, respectively; and an ethoxylated aliphatic alcohol-based compound comprising a PEO block; including one or more of

Hereinafter, each step will be described in detail.

In the method for producing a super absorbent polymer according to an embodiment of the present invention, step 1 is a step of forming a hydrogel polymer.

Specifically, the hydrogel polymer may be prepared by cross-linking a water-soluble ethylenically unsaturated monomer containing an acid group and having at least a portion of the acid group neutralized with a polymerizable antibacterial monomer, in the presence of a surfactant and an internal cross-linking agent. .

More specifically, a monomer composition is prepared by mixing the water-soluble ethylenically unsaturated monomer, a polymerizable antibacterial monomer, and an internal crosslinking agent in a solvent, and a surfactant is added to the prepared monomer composition, followed by crosslinking polymerization.

When a surfactant is added to the monomer composition, the hydrophobic portion of the surfactant surrounds the polymerizable antibacterial monomer to form stable micelles. In addition, since the surfactant structurally contains sufficient hydrophobic chains and hydrophilic chains to form micelles centered on the polymerizable antibacterial monomer, it is possible to improve the dispersibility of the polymerizable antibacterial monomer in the monomer composition. Specifically, the surfactant includes a block copolymer comprising at least one polypropylene oxide block and one or more polyethylene oxide blocks, respectively; and an ethoxylated aliphatic alcohol-based compound comprising a polyethylene oxide block; One or more of them may be used. As a polymerizable antibacterial monomer, the terpene-based compound has a carbon skeleton having isoprene as a basic unit structure and exhibits hydrophobicity. Accordingly, it is not easy to form micelles for terpene-based compounds with conventional surfactants. However, the surfactants can form micelles by sufficiently enclosing the hydrophobic terpene-based compound due to their unique structure, and as a result, the dispersibility of the terpene-based compound in the monomer composition can be greatly improved.

In addition, as the block copolymer, specifically, polyethylene oxide-polypropylene oxide-polyethylene oxide (PEO-PPO-PEO) or polypropylene oxide-polyethylene oxide-polypropylene oxide (PPO-PEO-PPO) type ternary block copolymer ( triblock copolymer) may be used, and more specifically, a compound represented by the following Chemical Formula 1 may be used:

[Formula 1]

In Formula 1, x, y, and z are each independently an integer of 1 or more, more specifically, x and z are each independently an integer of 50 or more, or 60 or more, 150 or less, or 120 or less, or 110 or less integer; , y may be an integer of 20 or more, or 25 or more, and 80 or less, or 70 or less, where x+z is 100 or more, or 120 or more, and 300 or less, or 250 or less, or 220 or less.

The block copolymer has a weight average molecular weight of 5,000 g/mol or more, or 7000 g/mol or more, or 75,00 g/mol or more, and 15,000 g/mol or less, or 14,000 g/mol or less, or 13,000 g/mol or less. have. When it has a weight average molecular weight within the above range, it can stably exhibit an effect of improving dispersibility with respect to the polymerizable antibacterial monomer.

The block copolymer may be prepared and used to satisfy the structural conditions described above, or may be commercially obtained and used, such as Pluronic™ PE6800 (or Pluronic™ F68), Pluronic™ F127, and Pluronic™ F87.

In addition, as the ethoxylated aliphatic alcohol-based compound containing the polyethylene oxide block, a compound represented by the following Chemical Formula 2 may be specifically used:

[Formula 2]

In Formula 2,

H is hydrogen,

L is a straight-chain alkylene having 10 to 30 carbon atoms,

w is an integer greater than or equal to 1.

More specifically, in Formula 2, L may be a straight-chain alkylene having 12 to 24 carbon atoms, and more specifically, 1,18-octadecane-diyl.

In addition, in Formula 2, w is 10 or more, or 20 or more, or 50 or more, or 70 or more, or 90 or more, and may be an integer of 120 or less, or 100 or less.

The ethoxylated aliphatic alcohol-based compound including the polyethylene oxide block may be directly prepared and used, or may be commercially obtained and used, such as Brij™ S100.

Among the surfactants described above, surfactants having a Hydrophile-Lipophole balance (HLB) of 14 to 30 according to Davis calculation method may be used.

If the HLB is less than 14, the hydrophobicity is too strong and it is difficult to be dispersed in the hydrophilic monomer composition SAP composition, and if it exceeds 30, the hydrophilicity is too strong and it is difficult to disperse the hydrophobic terpene-based polymerizable antibacterial monomer. More specifically, the surfactant may have an HLB of 14 or more, or 15 or more, or 16 or more, and 30 or less, or 28 or less, or 25 or less.

The surfactant may be added in an amount of 10 to 3000 ppm based on the weight of the water-soluble ethylenically unsaturated monomer used. If the amount of surfactant is less than 10 ppm, the effect of improving the dispersibility is insignificant, and if it exceeds 3000 ppm, the sheet-like hydrogel polymer formed while polymerization of the monomer composition is excessively swollen. Therefore, a large amount of unreacted monomer composition may be generated. In order to obtain a sufficient dispersibility improvement effect while minimizing the amount of unreacted monomer composition, the surfactant is 10 ppm or more, or 50 ppm or more, or 100 ppm or more, or 200 ppm or more, or 500 ppm or more, or 1000 ppm or more, 3000 ppm or less, or It may be added in an amount of 2700 ppm or less, or 2500 ppm or less, or 2000 ppm or less.

Meanwhile, as the polymerizable antibacterial monomer for imparting antibacterial properties to the superabsorbent polymer, a terpene-based compound including at least one ethylenically unsaturated functional group capable of cross-linking polymerization with the water-soluble ethylenically unsaturated monomer may be used.

The polymerizable antibacterial monomer is prepared by introducing one or more ethylenically unsaturated functional groups to a terpene-based compound used as an antibacterial agent, and is bonded to the antibacterial agent-derived structure together with a terpene-based compound-derived structure as an antibacterial agent. It contains at least one ethylenically unsaturated functional group capable of cross-linking polymerization with a water-soluble ethylenically unsaturated monomer. As a result, it is possible to simultaneously exhibit antimicrobial properties and polymerizability.

Since the polymerizable antibacterial monomer has hydrophobicity, it is non-uniformly dispersed in the monomer composition by itself, but can be uniformly dispersed in the monomer composition due to the unique structure of the surfactant when used in combination with the aforementioned surfactant.

In the polymerizable antibacterial monomer, the ethylenically unsaturated functional group may be specifically a vinyl group, an allyl group, or a (meth)acrylic group, and any one or two or more thereof may be included.

In addition, the terpene-based compound may be, specifically, a menthol-based compound, a citronellol-based compound, a limonene-based compound, or an icaridine-based compound, and any one or a mixture of two or more thereof may be used.

In addition, the polymerizable antibacterial monomer comprising a structure derived from the menthol-based compound may be a compound represented by the following formula (3), and the polymerizable antibacterial monomer comprising a structure derived from the citronellol-based compound is represented by the following formula (4) It may be a compound that becomes

[Formula 3]

[Formula 4]

In Formulas 3 and 4,

Q ₆ and Q ₇ are ethylenically unsaturated functional groups such as vinyl, allyl, (meth)acryloyl, (meth)acryloyloxy, allyloxycarbonyl or allyloxy.

More specific examples may include compounds represented by the following Chemical Formulas 3a and 4a, respectively.

The polymerizable antibacterial monomer binds an ethylenically unsaturated functional group to a compound usually used as an antibacterial agent, and may be prepared using a chemical reaction capable of introducing an ethylenically unsaturated functional group, and the preparation method is not particularly limited. .

The polymerizable antibacterial monomer is included in the superabsorbent polymer as a cross-linked polymer by cross-linking polymerization with a water-soluble ethylenically unsaturated monomer. Accordingly, it is possible to enhance the antibacterial and deodorizing properties of the superabsorbent polymer by controlling the content of the structural unit (or repeating unit) derived from the polymerizable antibacterial monomer.

Specifically, the superabsorbent polymer according to an embodiment of the present invention may include the polymerizable antibacterial monomer-derived structural unit in an amount of 0.01 to 10% by weight based on the total weight of the superabsorbent polymer. When included in the above content range, excellent antibacterial and deodorizing properties can be continuously and stably exhibited. If it is included in an excessively low content of less than 0.01% by weight outside the above content range, it is difficult to implement sufficient antibacterial and deodorant properties, and if it exceeds 10% by weight, antibacterial and deodorant properties are increased, but the absorption capacity of the superabsorbent polymer There is a possibility that physical properties may be deteriorated.

Accordingly, the polymerizable antimicrobial monomer may be used in an amount to satisfy the content range of the polymerizable antimicrobial monomer-derived structural unit in the superabsorbent polymer. Specifically, it may be used in an amount of 0.01 to 80 parts by weight based on 100 parts by weight of the water-soluble ethylenically unsaturated monomer. When the content of the antimicrobial monomer is less than 0.01 parts by weight, it is difficult to exhibit sufficient bacterial growth inhibitory properties and deodorizing properties, and when the content of the antibacterial monomer exceeds 80 parts by weight, there is a risk of deterioration of physical properties such as absorption capacity of the superabsorbent polymer produced.

Meanwhile, as the water-soluble ethylenically unsaturated monomer for preparing the superabsorbent polymer, any monomer commonly used in the superabsorbent polymer may be used without particular limitation. Here, any one or more monomers selected from the group consisting of anionic monomers and salts thereof, nonionic hydrophilic monomers, amino group-containing unsaturated monomers, and quaternaries thereof may be used.

Specifically, (meth)acrylic acid, maleic anhydride, fumaric acid, crotonic acid, itaconic acid, 2-acryloylethane sulfonic acid, 2-methacryloylethane sulfonic acid, 2-(meth)acryloylpropanesulfonic acid or 2- (meth)acrylamide-2-methyl propane sulfonic acid anionic monomer and its salt; (meth) acrylamide, N-substituted (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, methoxy polyethylene glycol (meth) acrylate or polyethylene glycol ( meth) a nonionic hydrophilic-containing monomer of acrylate; and (N,N)-dimethylaminoethyl (meth)acrylate or (N,N)-dimethylaminopropyl (meth)acrylamide containing an amino group-containing unsaturated monomer and a quaternary product thereof can

More preferably, acrylic acid or a salt thereof, for example, an alkali metal salt such as acrylic acid or a sodium salt thereof may be used. Using such a monomer, a superabsorbent polymer having better physical properties can be prepared. When the alkali metal salt of acrylic acid is used as a monomer, it may be used by neutralizing the acrylic acid with a basic compound such as caustic soda (NaOH). In this case, the degree of neutralization may be 40 to 95 mol%, or 40 to 80 mol%, or 45 to 75 mol%. The range of the degree of neutralization may vary depending on the final physical properties, but if the degree of neutralization is too high, the neutralized monomer is precipitated and it may be difficult for polymerization to proceed smoothly. It can exhibit properties like elastic rubber, which is difficult to handle.

In addition, the internal crosslinking agent includes a crosslinking agent having at least one functional group capable of reacting with a water-soluble substituent of the water-soluble ethylenically unsaturated monomer and having at least one ethylenically unsaturated group; Alternatively, a crosslinking agent having at least two functional groups capable of reacting with a water-soluble substituent of the monomer and/or a water-soluble substituent formed by hydrolysis of the monomer may be used.

Specific examples of the internal crosslinking agent include bisacrylamide having 8 to 12 carbon atoms, bismethacrylamide, poly(meth)acrylate of a polyol having 2 to 10 carbon atoms, or poly(meth)allyl ether of a polyol having 2 to 10 carbon atoms, etc. and more specifically, N,N'-methylenebis(meth)acrylate, ethyleneoxy(meth)acrylate, polyethyleneoxy(meth)acrylate, propyleneoxy(meth)acrylate, glycerin diacrylate , glycerin triacrylate, trimethylol triacrylate, triallylamine, triaryl cyanurate, triallyl isocyanate, polyethylene glycol diacrylate, polyethylene glycol, diethylene glycol and at least one selected from the group consisting of propylene glycol can be used

The internal crosslinking agent may be included in an amount of 0.01 to 1 part by weight based on 100 parts by weight of the water-soluble ethylenically unsaturated monomer to crosslink the polymerized polymer. When the content of the internal crosslinking agent is less than 0.01 parts by weight, the improvement effect due to crosslinking is insignificant, and when the content of the internal crosslinking agent exceeds 1 part by weight, the absorbency of the superabsorbent polymer may decrease. More specifically, the internal crosslinking agent may be included in an amount of 0.05 parts by weight or more, or 0.1 parts by weight or more, and 0.5 parts by weight or less, or 0.3 parts by weight or less based on 100 parts by weight of the water-soluble ethylenically unsaturated monomer.

In addition, a polymerization initiator may be further added during the cross-linking polymerization.

Specifically, as the polymerization initiator, a photopolymerization initiator according to UV irradiation may be used. However, even by the photopolymerization method, a certain amount of heat is generated by irradiation such as ultraviolet irradiation, and a certain amount of heat is generated according to the progress of the polymerization reaction, which is an exothermic reaction, so a thermal polymerization initiator may be additionally included.

The photopolymerization initiator may be used without limitation in its composition as long as it is a compound capable of forming radicals by light such as ultraviolet rays.

As the photopolymerization initiator, for example, benzoin ether, dialkyl acetophenone, hydroxyl alkylketone, phenyl glyoxylate, benzyl dimethyl ketal Ketal), acyl phosphine (acyl phosphine), and alpha-aminoketone (α-aminoketone) may be used at least one selected from the group consisting of. On the other hand, as a specific example of the acylphosphine, commercially available lucirin TPO, that is, diphenyl(2,4,6-trimethylbenzoyl)-phosphine oxide may be used. For a more diverse range of photoinitiators, see Reinhold Schwalm, “UV Coatings: Basics, Recent Developments and New Applications (Elsevier 2007),” p. 115, and not limited to the above example.

The photopolymerization initiator may be included in an amount of 0.001 to 1 part by weight based on 100 parts by weight of the water-soluble ethylenically unsaturated monomer. When the content of the photopolymerization initiator is less than 0.001 parts by weight, the polymerization rate may be slowed, and when the content of the photopolymerization initiator exceeds 1 part by weight, the molecular weight of the superabsorbent polymer may be small and physical properties may be non-uniform. More specifically, the photopolymerization initiator is 0.005 parts by weight or more, or 0.01 parts by weight or more, or 0.1 parts by weight or more, and 0.5 parts by weight or less, or 0.3 parts by weight or less, based on 100 parts by weight of the water-soluble ethylenically unsaturated monomer. can be included as

In addition, when a thermal polymerization initiator is further included as the polymerization initiator, one or more selected from the group consisting of a persulfate-based initiator, an azo-based initiator, hydrogen peroxide and ascorbic acid may be used as the thermal polymerization initiator. Specifically, examples of the persulfate-based initiator include sodium persulfate (Na ₂ S ₂ O ₈ ), potassium persulfate (K ₂ S ₂ O ₈ ), ammonium persulfate (Ammonium persulfate; (NH ₄ ) ₂ S ₂ O ₈ ) and the like, and examples of the azo-based initiator include 2,2-azobis-(2-amidinopropane)dihydrochloride (2,2-azobis(2-amidinopropane) dihydrochloride), 2 , 2-Azobis-(N,N-dimethylene)isobutyramidine dihydrochloride (2,2-azobis-(N,N-dimethylene)isobutyramidine dihydrochloride), 2-(carbamoylazo)isobutyronitrile (2-(carbamoylazo)isobutylonitril), 2,2-azobis[2-(2-imidazolin-2-yl)propane]dihydrochloride (2,2-azobis[2-(2-imidazolin-2- yl)propane] dihydrochloride), and 4,4-azobis-(4-cyanovaleric acid). For more various thermal polymerization initiators, see Odian's book 'Principle of Polymerization (Wiley, 1981)', p. 203, and is not limited to the above example.

The thermal polymerization initiator may be included in an amount of 0.001 to 1 part by weight based on 100 parts by weight of the water-soluble ethylenically unsaturated monomer. If the content of the thermal polymerization initiator is less than 0.001 parts by weight, additional thermal polymerization hardly occurs, and the effect of adding the thermal polymerization initiator may be insignificant. If the content of the thermal polymerization initiator exceeds 1 part by weight, the molecular weight of the superabsorbent polymer is small and The physical properties may become non-uniform. More specifically, the thermal polymerization initiator is 0.005 parts by weight or more, or 0.01 parts by weight or more, or 0.1 parts by weight or more, and 0.5 parts by weight or less, or 0.3 parts by weight or less based on 100 parts by weight of the water-soluble ethylenically unsaturated monomer. may be included.

In addition to the polymerization initiator, one or more additives such as a surfactant, a thickener, a plasticizer, a storage stabilizer, and an antioxidant may be further included as needed during cross-linking polymerization.

The above-described water-soluble ethylenically unsaturated monomer, a polymerizable antibacterial monomer, and an internal crosslinking agent, and optionally a photopolymerization initiator, and a monomer composition comprising an additive may be prepared in the form of a solution dissolved in a solvent.

The solvent that can be used at this time can be used without limitation in its composition as long as it can dissolve the above-mentioned components, for example, 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, cyclohexanone, cyclopentanone, diethylene glycol monomethyl ether, diethylene glycol At least one selected from ethyl ether, toluene, xylene, butyrolactone, carbitol, methyl cellosolve acetate and N, N-dimethylacetamide may be used in combination. The solvent may be included in the remaining amount excluding the above-mentioned components with respect to the total content of the monomer composition.

In addition, when a water-soluble solvent such as water is used as the solvent and a terpene-based compound that does not show solubility in water is used as the polymerizable antibacterial monomer, in order to increase solubility, 10 parts by weight based on 100 parts by weight of the polymerizable antibacterial monomer A surfactant may be additionally added in an amount less than or equal to parts.

On the other hand, as long as the method of photopolymerizing such a monomer composition to form a hydrogel polymer is also a commonly used polymerization method, there is no particular limitation on the structure.

Specifically, the photopolymerization may be performed by irradiating ultraviolet rays having an intensity of 3 to 30 mW, or 10 to 20 mW at a temperature of 60 to 90 °C, or 70 to 80 °C. In the case of photopolymerization under the above conditions, it is possible to form a crosslinked polymer with better polymerization efficiency.

In addition, when the photopolymerization is carried out, it may be carried out in a reactor equipped with a movable conveyor belt, but the polymerization method described above is an example, and the present invention is not limited to the polymerization method described above.

In addition, as described above, when photopolymerization is carried out in a reactor equipped with a movable conveyor belt, the obtained hydrogel polymer may be a sheet-like hydrogel polymer having the width of the belt. At this time, the thickness of the polymer sheet varies depending on the concentration of the injected monomer composition and the injection rate, but it is preferable to supply the monomer composition so that a sheet-like polymer having a thickness of about 0.5 to about 5 cm can be obtained. When the monomer composition is supplied so that the thickness of the polymer in the sheet is too thin, the production efficiency is low, which is not preferable. When the thickness of the polymer in the sheet exceeds 5 cm, the polymerization reaction occurs evenly over the entire thickness due to the excessive thickness it may not be

In addition, the water content of the hydrogel polymer obtained by the above method may be about 40 to about 80 wt% based on the total weight of the hydrogel polymer. Meanwhile, throughout the present specification, "moisture content" refers to a value obtained by subtracting the weight of the polymer in a dry state from the weight of the hydrogel polymer as the amount of moisture occupied with respect to the total weight of the hydrogel polymer. Specifically, it is defined as a value calculated by measuring the weight loss due to evaporation of moisture in the polymer during drying by raising the temperature of the polymer through infrared heating. At this time, the drying condition is set to 20 minutes including 5 minutes of the temperature rising step in such a way that the temperature is raised from room temperature to about 180° C. and then maintained at 180° C., and the moisture content is measured.

Meanwhile, after the preparation of the hydrogel polymer, a coarse grinding process of pulverizing the hydrogel polymer prepared prior to subsequent drying and grinding processes may be optionally performed.

The coarse grinding process is a process for increasing the drying efficiency in the subsequent drying process and controlling the particle size of the superabsorbent polymer powder to be manufactured. At this time, the grinder used is not limited in configuration, but specifically, Vertical pulverizer, Turbo cutter, Turbo grinder, Rotary cutter mill, Cutter mill, Disc mill, Shred crusher ), a crusher (Crusher), a meat chopper (meat chopper), and may include any one selected from the group of crushing devices consisting of a disc cutter (Disc cutter), but is not limited to the above-described example.

The coarse grinding process may be performed, for example, so that the particle diameter of the hydrogel polymer is about 2 to about 10 mm. It is not technically easy to pulverize the hydrogel polymer having a particle diameter of less than 2 mm due to the high water content of the hydrogel polymer, and also aggregation between the pulverized particles may occur. On the other hand, when the particle diameter is more than 10 mm, the effect of increasing the efficiency of the drying step made later is insignificant.

Next, step 2 is a step of drying, pulverizing, and classifying the hydrogel polymer prepared in step 1 to form a base resin powder.

The drying method may be selected and used without limitation in its configuration, as long as it is commonly used as a drying process for the hydrogel polymer. Specifically, the drying step may be performed by a method such as hot air supply, infrared irradiation, microwave irradiation, or ultraviolet irradiation.

Specifically, the drying may be performed at a temperature of about 150 to about 250 ℃. When the drying temperature is less than 150°C, the drying time is excessively long and there is a risk that the physical properties of the superabsorbent polymer to be finally formed may decrease. fine powder may occur, and there is a risk that the physical properties of the superabsorbent polymer finally formed may be deteriorated. Therefore, preferably, the drying may be carried out at a temperature of 150 °C or higher, or 160 °C or higher, 200 °C or lower, or 180 °C or lower.

On the other hand, in the case of the drying time, in consideration of process efficiency, etc., it may be carried out for about 20 to about 90 minutes, but is not limited thereto.

After the drying step, the moisture content of the polymer may be about 5 to about 10% by weight.

After the drying process, a grinding process is performed.

The pulverization process may be performed so that the particle diameter of the polymer powder, that is, the base resin powder, is about 150 to about 850 μm. The grinder used for grinding to such a particle size is specifically, a pin mill, a hammer mill, a screw mill, a roll mill, a disc mill, or a jog. A mill (jog mill) or the like may be used, but the present invention is not limited to the above-described examples.

In addition, after the pulverization step as described above, in order to manage the physical properties of the superabsorbent polymer powder to be finalized, a process of classifying the pulverized polymer powder according to particle size may be further performed.

Preferably, a polymer having a particle diameter of about 150 to about 850 μm is classified, and only the polymer having such a particle diameter is used as a base resin powder to be commercialized through a surface crosslinking reaction step.

The base resin powder obtained as a result of the above process may have a fine powder form including a cross-linked polymer in which a water-soluble ethylenically unsaturated monomer and a polymerizable antibacterial monomer are cross-linked and polymerized through an internal cross-linking agent. Specifically, the base resin powder may have a fine powder form having a particle diameter of 150 to 850 μm.

Next, step 3 is a step of further crosslinking (or surface crosslinking) by heat-treating the base resin powder prepared in step 2 in the presence of a surface crosslinking agent.

The additional crosslinking is a step of increasing the crosslink density near the surface of the base resin powder in relation to the crosslink density inside the particles. In general, the surface crosslinking agent is applied to the surface of the base resin powder. Therefore, this reaction takes place on the surface of the base resin powder, which improves the cross-linking property on the surface of the particle without substantially affecting the inside of the particle. Therefore, the surface cross-linked base resin powder has a higher degree of cross-linking near the surface than inside.

In this additional crosslinking step, a surface crosslinking solution containing the surface crosslinking agent and an aqueous solvent may be used.

The surface crosslinking agent is not limited in its composition as long as it is a compound capable of reacting with a functional group of the polymer. Preferably, in order to improve the properties of the resulting super absorbent polymer, a polyhydric alcohol-based compound as the surface crosslinking agent; epoxy compounds; polyamine compounds; haloepoxy compounds; condensation products of haloepoxy compounds; oxazoline compounds; mono-, di- or polyoxazolidinone compounds; cyclic urea compounds; polyvalent metal salts; And one or more selected from the group consisting of alkylene carbonate-based compounds may be used.

Specifically, examples of the polyhydric alcohol compound include ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, 1,2-hexanediol, 1,3-hexanediol, Selected from the group consisting of 2-methyl-1,3-propanediol, 2,5-hexanediol, 2-methyl-1,3-pentanediol, 2-methyl-2,4-pentanediol, tripropylene glycol and glycerol It is possible to use one or more of the following.

In addition, as the epoxy compound, ethylene glycol diglycidyl epoxide, ethylene glycol diglycidyl ether, glycidol, etc. can be used, and as the polyamine compound, ethylenediamine, diethylenetriamine, and triethylenetetraamine , tetraethylenepentamine, pentaethylenehexamine, polyethyleneimine, and at least one selected from the group consisting of polyamide polyamine may be used.

And as the haloepoxy compound, epichlorohydrin, epibromohydrin, and α-methylepichlorohydrin may be used. Meanwhile, as the mono-, di- or polyoxazolidinone compound, for example, 2-oxazolidinone may be used.

As the alkylene carbonate-based compound, an alkylene carbonate having 2 to 6 carbon atoms, such as ethylene carbonate or propylene carbonate, may be used. These may be used individually, or two or more types of alkylene carbonates having different carbon numbers may be mixed and used.

In addition, as the polyvalent metal salt, specifically, a metal-containing sulfate such as aluminum or a carboxylate may be used, and among them, aluminum sulfate may be more preferably used.

The surface crosslinking agent may be added in an amount of 0.001 to 5 parts by weight based on 100 parts by weight of the base resin powder. For example, the surface crosslinking agent is 0.005 parts by weight or more, 0.01 parts by weight or more, or 0.1 parts by weight or more, and 3 parts by weight or less, or 2 parts by weight or less, or 1 part by weight or less based on 100 parts by weight of the base resin powder. content can be used. By adjusting the content range of the surface crosslinking agent to the above-mentioned range, it is possible to prepare a superabsorbent polymer having excellent absorption performance and various physical properties such as liquid permeability. If the content of the surface crosslinking agent is too small, the surface crosslinking reaction hardly occurs, and when it exceeds 5 parts by weight based on 100 parts by weight of the base resin powder, the absorption capacity and physical properties may deteriorate due to the excessive surface crosslinking reaction proceeding. have.

In addition, during the additional crosslinking, an antibacterial agent may be further added together with the surface crosslinking agent.

As the antibacterial agent, a cationic compound, a terpene-based compound, or an alcohol-based compound may be used. Specifically, the cationic compound may be a biguanide-based compound, a guanidine-based compound, a benzoimidazole-based compound, a benzothiazole-based compound, or an ammonium-based compound, any one or a mixture of two or more thereof can be used In addition, the terpene-based compound may be, specifically, a menthol-based compound, a citronellol-based compound, a limonene-based compound, or an icaridine-based compound, and any one or a mixture of two or more thereof may be used. In addition, the alcohol-based compound, specifically, may be a phenol-based compound.

The antibacterial agent may be added in an amount of 0.01 to 10 parts by weight based on 100 parts by weight of the base resin powder, and when added in the above content range, it may exhibit increased antibacterial and deodorizing properties while maintaining excellent physical properties of the superabsorbent polymer.

There is no limitation on the composition of the method for mixing the surface crosslinking agent and optionally the antibacterial agent with the base resin powder. A method of mixing the surface crosslinking agent, the antimicrobial agent, and the base resin powder in a reaction tank, spraying the surface crosslinking agent on the base resin powder, continuously supplying the base resin powder, the surface crosslinking agent and the antibacterial agent to a continuously operated mixer and mixing, etc. can be used

In addition to the surface crosslinking agent, water and alcohol may be mixed together and added in the form of the surface crosslinking solution. When water and alcohol are added, there is an advantage that the surface crosslinking agent can be uniformly dispersed in the base resin powder. At this time, the content of the added water and alcohol is about 5 to about 5 parts by weight of the polymer for the purpose of inducing even dispersion of the surface crosslinking agent and preventing agglomeration of the base resin powder and at the same time optimizing the surface penetration depth of the crosslinking agent. It is preferably added in a proportion of about 12 parts by weight.

The surface crosslinking reaction may be performed by heating the base resin powder to which the surface crosslinking agent and optionally the antimicrobial agent are added at a temperature of about 80 to about 220° C. for about 15 to about 100 minutes. When the crosslinking reaction temperature is less than 80°C, the surface crosslinking reaction may not sufficiently occur, and when it exceeds 220°C, the surface crosslinking reaction may proceed excessively. In addition, if the crosslinking reaction time is too short (less than 15 minutes), a sufficient crosslinking reaction cannot be carried out. can More specifically, it can proceed by heating at a temperature of 120°C or higher, or 140°C or higher, 200°C or lower, or 180°C or lower, for 20 minutes or more, or 40 minutes or more, 70 minutes or less, or 60 minutes or less. .

A means for increasing the temperature for the additional crosslinking reaction is not particularly limited. It can be heated by supplying a heating medium or by directly supplying a heat source. At this time, as the type of heating medium that can be used, a fluid having an elevated temperature such as steam, hot air, or hot oil may be used, but the present invention is not limited thereto. It can be appropriately selected in consideration of the target temperature. On the other hand, the directly supplied heat source may be a heating method through electricity or a heating method through a gas, but the present invention is not limited to the above-described example.

The super absorbent polymer may be manufactured and provided through the above-described manufacturing process. .

The superabsorbent polymer to be prepared includes a base resin powder comprising a water-soluble ethylenically unsaturated monomer containing an acidic group and at least partially neutralized with an acidic group, a crosslinked polymer of a polymerizable antibacterial monomer, and a crosslinked polymer of the base resin powder. and a surface crosslinking layer formed on the base resin powder by further crosslinking through a surface crosslinking agent. By including the structural unit derived from the antibacterial agent in the polymer chain of the base resin powder as described above, it is possible to continuously and safely exhibit improved bacterial growth inhibitory properties and deodorizing properties without deterioration of physical properties of the superabsorbent polymer, such as water holding capacity and absorbency under pressure.

In addition, in the additional crosslinking step (surface crosslinking step) of the base resin powder, as the superabsorbent polymer is further crosslinked by including an antibacterial agent in the surface crosslinking solution, the surface crosslinking layer of the superabsorbent polymer or the surface thereof It may further include an antibacterial material. At this time, since the antibacterial material is included in a physically or chemically fixed or bonded state, non-uniform application, detachment, and separation during transportation of the antibacterial agent do not occur, unlike the conventional antibacterial agent blending, and the antibacterial agent component is uniform throughout. It can stably exhibit excellent bacterial growth inhibitory properties and deodorant properties for a long time.

Accordingly, the superabsorbent polymer may be preferably included and used in various hygiene products, for example, children's paper diapers, adult diapers or sanitary napkins, and in particular, it is used in adult diapers where secondary odor caused by bacterial growth is a problem. It can be applied very preferably.

Such hygiene products may follow the constitution of conventional hygiene products, except that the superabsorbent polymer of one embodiment is included in the absorbent body.

The present invention will be described in more detail in the following examples. However, the following examples only illustrate the present invention, and the content of the present invention is not limited by the following examples.

Example 1

100 g of acrylic acid, 0.23 g of polyethylene glycol diacrylate (PEGDA, Mn=575 g/mol) as a crosslinking agent, 0.008 g of Bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide as a photoinitiator, sodium persulfate (SPS) as a thermal initiator ) 0.12 g, 98% caustic soda (NaOH) 39.7 g, water 132.28 g, Pluronic™ F127 as a surfactant (manufactured by BASF), and 0.5 g of Acryl-citronellol antibacterial monomer (4a) were mixed to prepare a monomer composition in an aqueous solution. . After receiving the monomer composition in the tray, UV irradiation was performed for 1 minute with a UV irradiation device while maintaining the polymerization atmosphere temperature of 80° C. (Irradiation amount: 4 mW/cm ² ), followed by UV polymerization by aging for 2 minutes to form a hydrogel polymer sheet prepared. The polymerized sheet was taken out and cut to a size of 3 cm×3 cm, and then dried in a vacuum oven at 120° C. for 10 hours. After drying, pulverization and classification were performed to prepare an antibacterial superabsorbent polymer having an average particle diameter of 300 to 600 μm.

Examples 2 to 4, and Comparative Examples 1 to 3

A superabsorbent polymer was prepared in the same manner as in Example 1, except that it was carried out under the conditions shown in Table 1 below. However, in Comparative Examples 2 and 3, the polymerization reaction did not proceed even after UV irradiation for 1 minute, so additional UV irradiation was performed for 2 minutes.

Antibacterial Monomer Type Antibacterial monomer usage
(parts by weight based on 100 parts by weight of acrylic acid) Surfactant type Surfactant usage
(ppm based on acrylic acid used weight) Example 1 Acryl-citronellol (4a) 0.5 Pluronic™ F127 1000 Example 2 Acryl-citronellol (4a) 0.5 Pluronic™ F127 2000 Example 3 Acryl-menthol
(3a) 0.5 Pluronic™ F127 200 Example 4 Acryl-menthol
(3a) 0.5 Pluronic™ F127 2000 Comparative Example 1 - 0 - 0 Comparative Example 2 Acryl-citronellol
(4a) 0.5 - 0 Comparative Example 3 Acryl-menthol
(3a) 0.5 - 0

The structures of Acryl-citronellol (4a) and Acryl-menthol (3a) used in Examples and Comparative Examples are as follows:

Test Example 1

The dispersibility improvement effect of the surfactant on the polymerizable antibacterial monomer was evaluated.

Specifically, 100 g of acrylic acid, 0.23 g of polyethylene glycol diacrylate (PEGDA, Mn=575 g/mol) as a crosslinking agent, 0.008 g of Bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide as a photoinitiator, and sodium persulfate (sodium) as a thermal initiator. Persulfate; SPS) 0.12 g, 98% caustic soda (NaOH) 39.7 g, water 132.28 g, and Acryl-citronellol 68 g as a polymerizable antibacterial monomer were mixed to prepare a monomer composition in an aqueous solution.

Each of the surfactants shown in Table 2 below was added to the prepared monomer composition in an amount of 2000 ppm based on the amount of acrylic acid used, and the degree of dispersion immediately after mixing and the degree of dispersion after mixing was observed 1 hour after mixing. The results are shown in FIGS. 1A to 1C, respectively.

Figure 1a is a sample No. Table 2 is described. It is a photograph observing the monomer composition immediately after the input of the surfactants of 1 to 7, FIG. 1b is a photograph observing the change of the monomer composition 1 hour after the addition of the surfactants, and FIG. 1c is sample no. It is a photograph observing the change of the monomer composition 1 hour after the addition of the surfactants of 8 to 11.

Sample No. Surfactant type structure HLB / Character One Triton™ X-100
(product made in SHOWA company)

n=9~10

n=9~10 13.5 / liquid 2 Pluronic™ F127
(product made in BASF company)

x=100.225, y=65.17, z=100.225 22 / solid 3 Pluronic™ F87
(product made in BASF company)

x=61.25, y=39.83, z=61.25 24 / solid 4 Pluronic™ PE6800
(product made in BASF company)

x=76.365, y=28.97, z=76.365 29 / solid 5 sodium stearate

18 / solid 6 Sodium Dodecyl Sulfate (SDS)

40 / solid 7 - - - 8 IGEPAL™ DM970
(product made in BASF company)

n=150 19/ solid (powder) 9 Brij™ S 100
(product made by Croda Inc.)

n=~100 18/ solid (powder) 10 LuTENSOL™ TO 20
(product made in BASF company)

16.5 / wax 11 TWEEN™ 20
(product made by Croda Inc.)

w+x+y+z=20 16 / liquid

In Table 2, Sample No. 7 indicates that no surfactant is added.

Experimental results, among various surfactants, a pluronic-based surfactant, which is a block copolymer containing at least one polypropylene oxide block and a polyethylene oxide block, respectively, and Brij™, an ethoxylated aliphatic alcohol compound containing a polyethylene oxide block It was confirmed that the surfactant of S100 exhibited an excellent dispersibility improvement effect on the terpene-based polymerizable antibacterial monomer due to its structural characteristics.

Test Example 2

The foaming rate and antibacterial properties of the superabsorbent polymers prepared in Examples and Comparative Examples were measured in the following manner, and the results are shown in Table 4.

(1) Polymerization rate (seconds): The time from the start of UV irradiation to the monomer composition to the time when a bubble popping sound is generated due to the polymerization reaction, that is, the time from when the monomer composition starts to gel was measured.

(2) antibacterial evaluation:

Manufacture of artificial urine

After preparing three types of solutions as shown in Table 3 below, the stock solution and the cationic solution were sterilized using a high-pressure sterilizer (120° C., 15 minutes) and then sufficiently cooled to room temperature. Urea/glucose solution was prepared by removing impurities using a 0.22㎛ syringe filter (hydrophilic, Sartorius stedium). The prepared stock solution 940ml, cationic solution 10ml, and urea/glucose solution 50ml were mixed and thoroughly mixed, and then used for the experiment.

Reagent name Usage (g) Stock solution sodium chloride 8.7660 Potassium phosphate dibasic trihydrate 4.5644 Sodium dihydrogen phosphate (dihydrate) 1. 5602 Ammonium chloride 2.6745 Sodium sulfate decahydrate 6.4440 Lactic acid (85% in H2) 0.5299 yeast extract 20.0000 Up to 1000ml cationic solution Magnesium chloride (hexahydrate) 1.2198 Calcium chloride (dehydrate) 0.8821 Up to 20ml Urea/glucose solution Urea 36.0360 D-glucose 0.1802 Up to 100ml

Antimicrobial evaluation

Unless otherwise indicated, the following physical property evaluation was conducted at constant temperature and humidity (23±1° C., relative humidity 50±10%).

After putting 2 g of the superabsorbent polymer prepared in Examples and Comparative Examples into a 250 ml cell culture flask, 50 ml of artificial urine inoculated with 3000+-300 CFU/ml of Proteus mirabilis ATCC 29906 standard strain was injected. The superabsorbent polymer was mixed for about 1 minute to sufficiently absorb the solution. The superabsorbent polymer, which had sufficiently absorbed the solution, showed a gel form, and was incubated for 12 hours in a shaking incubator maintained at 37°C. 150ml of 0.9 wt% NaCl solution was added to the cultured sample and stirred in a shaking incubator for about 1 minute. The diluted solution was spread on an Agar medium plate. Serial dilution was performed to enable colony counting, and 0.9 wt% NaCl solution was used in this process. The bacteriostatic performance was calculated according to Equation 1 below after calculating the initial concentration of microorganisms (C0, CFU/ml) in consideration of the dilution concentration.

[Equation 1]

Bacteriostatic reduction rate (%)=(1-C _sample /C _reference )×100

In Equation 1 above,

C _sample = Initial microbial concentration of superabsorbent polymer containing bacteriostatic material (C ₀ )

C _reference = Initial microbial concentration of superabsorbent polymer without bacteriostatic material (C ₀ )

polymerization rate (sec) Antibacterial evaluation (Log CFU/ml) 1 time Episode 2 Example 1 155 6.8 6.7 Example 2 90 6.8 6.8 Example 3 76 6.7 6.8 Example 4 55 6.7 6.7 Comparative Example 1 77 7.3 7.4 Comparative Example 2 >180 6.6 7.3 Comparative Example 3 >180 6.5 7.1

As a result of the experiment, a specific structure, specifically, a block copolymer containing at least one polypropylene oxide block and a polyethylene oxide block, respectively, or an ethoxylated containing polyethylene oxide block in the preparation of a superabsorbent polymer using a polymerizable antibacterial monomer In the case of Examples in which the surfactant of the aliphatic alcohol-based compound was added within the optimum content range, the polymerization rate was fast, and the prepared superabsorbent polymer also exhibited excellent antibacterial properties.

Claims (17)

forming a hydrogel polymer by cross-linking a water-soluble ethylenically unsaturated monomer containing an acidic group and having at least a portion of the acidic group neutralized with a polymerizable antibacterial monomer, a surfactant and an internal crosslinking agent;
drying, pulverizing and classifying the hydrogel polymer to form a base resin powder; and
In the presence of a surface crosslinking agent, heat treatment of the base resin powder comprises the step of further crosslinking,
The polymerizable antibacterial monomer is a terpene-based compound containing an ethylenically unsaturated functional group,
The surfactant is a block copolymer comprising at least one polypropylene oxide block and one or more polyethylene oxide blocks, respectively; and an ethoxylated aliphatic alcohol-based compound comprising a polyethylene oxide block; A method for producing a super absorbent polymer, comprising at least one of them.
According to claim 1,
The block copolymer is a polyethylene oxide-polypropylene oxide-polyethylene oxide (PEO-PPO-PEO) or polypropylene oxide-polyethylene oxide-polypropylene oxide (PPO-PEO-PPO) form of a triblock copolymer (triblock copolymer) Phosphorus, manufacturing method.
According to claim 1,
The block copolymer is a compound represented by the following formula (1), manufacturing method:
[Formula 1]

In Formula 1, x, y, and z are each independently an integer of 1 or more
4. The method of claim 3,
Wherein x and z are each independently an integer of 50 to 150 or less,
The y is an integer of 20 to 80, in this case, x + z is 100 to 300, the manufacturing method.
According to claim 1,
The ethoxylated aliphatic alcohol-based compound is a compound represented by the following formula (2), preparation method:
[Formula 2]

In Formula 2,
H is hydrogen,
L is a straight-chain alkylene having 10 to 30 carbon atoms,
w is an integer greater than or equal to 1;
6. The method of claim 5,
L is 1,18-octadecane-diyl,
w is an integer from 10 to 120, the manufacturing method.
According to claim 1,
The surfactant has a Hydrophile-Lipophole balance (HLB) of 14 to 30 according to Davis calculation method.
According to claim 1,
The surfactant is added in an amount of 10 to 3000 ppm, the manufacturing method.
According to claim 1,
The ethylenically unsaturated functional group is vinyl, allyl, (meth)acryloyl, (meth)acryloyloxy, allyloxycarbonyl or allyloxy, the manufacturing method.
According to claim 1,
The terpene-based compound is a menthol-based compound, a citronellol-based compound, a limonene-based compound, or an icaridine-based compound.
According to claim 1,
The polymerizable antibacterial monomer is a compound represented by the following Chemical Formula 3 or Chemical Formula 4, the preparation method:
[Formula 3]

[Formula 4]

In Formulas 3 and 4,
Q ₆ and Q ₇ are each independently an ethylenically unsaturated functional group selected from the group consisting of vinyl, allyl, (meth)acryloyl, (meth)acryloyloxy, allyloxycarbonyl and allyloxy.
According to claim 1,
The polymerizable antibacterial monomer is any one selected from compounds having the following structure:

.
According to claim 1,
The polymerizable antibacterial monomer is added in an amount of 0.1 to 80 parts by weight based on 100 parts by weight of the water-soluble ethylenically unsaturated monomer.
According to claim 1,
The cross-linking polymerization is carried out by photopolymerization.
According to claim 1,
At the time of the additional crosslinking, at least one antimicrobial agent selected from the group consisting of a cationic compound, a terpene-based compound, and an alcohol-based compound is further added.
A superabsorbent polymer produced by the method according to any one of claims 1 to 15.
A hygiene product comprising a superabsorbent polymer produced by the method according to any one of claims 1 to 15.

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