KR20150061270A - Super Absorbent Polymer Resin And Method for Preparing The Same - Google Patents

Abstract

The present invention relates to a manufacturing method of super absorbent resin and, more specifically, a super absorbent resin, which is allowed to resolve a problem on the load of a crusher, while improving dryness rate by using fine re-assembly, and improves entire physical properties by reducing fine re-assembly whose strength is weak, and a manufacturing method thereof.

Description

Technical Field [0001] The present invention relates to a superabsorbent polymer and a method of preparing the same,

The present invention relates to a method of producing a superabsorbent resin, and more particularly, to a method of manufacturing a superabsorbent resin by using a fine pulverizing assembly, which solves the problems of drying efficiency and pulverizer load, Absorbing resin capable of reducing the amount of water and improving the overall physical properties, and a process for producing the same.

Super Absorbent Polymer (SAP) is a synthetic polymer material having a function of absorbing moisture of about 500 to 1,000 times its own weight and has been put to practical use as a physiological tool. As well as hygiene products, are widely used as soil remediation agents for gardening, index materials for civil engineering and construction, sheets for seedling growing, freshness keeping agents in the field of food distribution, and fomentation materials.

The absorption mechanism of such a superabsorbent resin is characterized in that the absorption mechanism of the superabsorbent resin is a combination of the permeation pressure due to the difference in electrical attraction represented by the charge of the polymer electrolyte, the affinity between water and the polymer electrolyte, the molecular expansion due to the repulsion between the polymer electrolyte ions, . That is, the water absorbency of the water absorbent resin depends on the above-described affinity and molecular swelling, and the rate of absorption depends largely on the penetration pressure of the water absorbent polymer itself.

A lot of research has been conducted to improve the absorption rate of such a superabsorbent resin. For example, Korean Patent Publication No. 2007-0012623 A discloses limiting the content ratio depending on the size of resin particles, And liquid permeability at the same time.

In order to solve the problem of the physical properties of the product, the fine powder which is necessarily generated in the process of manufacturing the superabsorbent resin is added with the fine powder at the time of polymerization, but this method induces non-uniform polymerization, Thereby causing deterioration of physical properties. A method of reassembling the fine particles by using a separate re-granulator has been developed. This method is a method of making fine particles by mixing a fine powder and water at a certain ratio. The problem with the above technique is that due to the small particle size of the fine particles, the absorption rate is accelerated and the moisture is mixed non-uniformly, so that non-uniformity occurs in the whole reassembly to produce a reassembly of unequal size and strength. On the other hand, , It gives damage to the apparatus at the time of crushing and weakly re-assembled particles are easily crushed and returned to the fine particles, thereby deteriorating the performance of the re-assembly.

Korea Patent Publication No. 2007-0012623

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems occurring in the prior art,

A superabsorbent resin which can improve the overall properties by preparing a uniform finely divided assembly by regulating the depth of absorption and the rate of absorption by using coagulability by using water as a solvent when reassembling the pulverization reassembly, The purpose of the method is to provide.

According to an aspect of the present invention,

Normal particles comprising superabsorbent resin particles having a particle size of 150 to 850 탆; And

50 to 200 parts by weight of superabsorbent resin particles having a particle size of 150 mu m or less and 100 parts by weight of water of the superabsorbent resin particles having a particle size of 150 mu m or less and 0.1 to 30 parts by weight of an additive per 100 parts by weight of the superabsorbent resin particles having a particle size of 150 mu m or less The present invention also provides a method for producing a superabsorbent resin-containing superabsorbent resin,

Further, the present invention provides a superabsorbent resin produced by the method for producing a superabsorbent resin.

The present invention also relates to a solid particle comprising superabsorbent resin particles having a particle size of 150 to 850 탆; And

50 to 200 parts by weight of superabsorbent resin particles having a particle size of 150 mu m or less and 100 parts by weight of water of the superabsorbent resin particles having a particle size of 150 mu m or less and 0.1 to 30 parts by weight of an additive per 100 parts by weight of the superabsorbent resin particles having a particle size of 150 mu m or less By weight of a water-soluble resin, and re-assembling the mixture.

According to the superabsorbent resin according to the present invention, as compared with the superabsorbent resin used in the past, water is used as a solvent in the pulverization of the pulverizer to increase the cohesive force, while the absorption depth and the absorption rate are controlled using additives, There is an advantage in that a homogeneous pulverized product can be produced through reaction with the resin particles. In addition, the reassembled finely divided assembly can ensure a reassembly having a relatively uniform size, strength, and water content by uniformly absorbing water. Through this, it is possible to obtain a reassembly similar to the crumb obtained after the polymerization, to improve the drying efficiency, and to solve the problem of load applied to the crusher. In addition, the amount of the fine particles to be recycled can be reduced by reducing the content of the weakly dispersed fine particles, which has the advantage that the overall properties can be improved.

Hereinafter, the present invention will be described in detail.

The method for producing a superabsorbent resin according to the present invention comprises

Normal particles comprising superabsorbent resin particles having a particle size of 150 to 850 탆; And

50 to 200 parts by weight of superabsorbent resin particles having a particle size of 150 mu m or less and 100 parts by weight of water of the superabsorbent resin particles having a particle size of 150 mu m or less and 0.1 to 30 parts by weight of an additive per 100 parts by weight of the superabsorbent resin particles having a particle size of 150 mu m or less By mass of the fine particles and the re-assembled finely divided product.

Further, in the method for producing a superabsorbent resin according to the present invention, the superabsorbent resin-containing superabsorbent resin-containing superabsorbent resin may be prepared by mixing the fine pulverization re-assembly with 30 parts by weight based on 100 parts by weight of the total weight of the normal particles and the fine pulverization- By weight or less.

The method for producing a superabsorbent resin-containing superabsorbent resin according to the present invention comprises the steps of:

a) preparing a hydrogel polymer by thermal polymerization or photopolymerization of a monomer composition comprising a water-soluble ethylenically unsaturated monomer and a polymerization initiator;

b) drying the hydrogel polymer;

c) pulverizing the dried hydrous gel polymer to obtain superabsorbent resin particles;

d) Particles having a particle size of less than 150 탆, particles having a particle size of 150 탆 or more and less than 300 탆, particles having a particle size of 300 탆 or more and less than 450 탆, particles having a particle size of not less than 450 탆 and less than 600 탆, And particles having a particle size of 850 탆 or more; And

e) normal particles comprising the superabsorbent resin particles having a particle size of 150 to 850 탆; And

50 to 200 parts by weight of superabsorbent resin particles having a particle size of 150 mu m or less and 100 parts by weight of water of the superabsorbent resin particles having a particle size of 150 mu m or less and 0.1 to 30 parts by weight of an additive per 100 parts by weight of the superabsorbent resin particles having a particle size of 150 mu m or less Absorbing resin particles containing fine aggregate assembled by mixing a re-agglomerated fine aggregate and a re-aged fine aggregate.

For reference, the term " superabsorbent resin particles " as used in the present invention refers to dried and pulverized hydrogel polymers. More specifically, the hydrogel polymer is a solid jelly-like material having a size of 1 cm or more, which has been polymerized and contains a large amount of water (50% or more), and the hydrogel polymer is dried and pulverized, Particle. The hydrogel polymer thus corresponds to the intermediate state of the process.

First, a method of producing a superabsorbent resin according to the present invention is a step of preparing a hydrogel polymer by thermally polymerizing or photopolymerizing a monomer composition comprising a) a water-soluble ethylenically unsaturated monomer and a polymerization initiator.

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

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

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

In the method for producing a superabsorbent resin according to the present invention, the water-soluble ethylenically unsaturated monomer is not particularly limited as long as it is a monomer usually used in the production of a superabsorbent resin, but preferably an anionic monomer and its salt, At least one selected from the group consisting of an ionic hydrophilic-containing monomer and an amino group-containing unsaturated monomer and a quaternary car- bon thereof can be used. Specific examples include acrylic acid, methacrylic acid, maleic anhydride, fumaric acid, crotonic acid, itaconic acid, 2-acryloylethanesulfonic acid, 2- methacryloylethanesulfonic acid, 2- (meth) acryloylpropanesulfonic acid, - anionic monomers of (meth) acrylamide-2-methylpropanesulfonic acid and salts thereof; (Meth) acrylamide, N-substituted (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, methoxypolyethylene glycol (meth) acrylate or polyethylene glycol Non-ionic hydrophilic-containing monomer of (meth) acrylate; And at least one selected from the group consisting of unsaturated monomers containing an amino group of (N, N) -dimethylaminoethyl (meth) acrylate or (N, N) -dimethylaminopropyl (meth) Acrylic acid or a salt thereof can be used. When acrylic acid or a salt thereof is used as a monomer, there is an advantage that a highly water-absorbent resin with improved water absorption can be obtained.

Meanwhile, in the method for producing a superabsorbent resin according to the present invention, the concentration of the water-soluble ethylenically unsaturated monomer in the monomer composition can be appropriately selected in consideration of the polymerization time and the reaction conditions, and is preferably 40 to 55 wt% . When the concentration of the water-soluble ethylenically unsaturated monomer is less than 40% by weight, it is economically disadvantageous. When it exceeds 55% by weight, the stability of the unsaturated monomer mixture and the physical properties of the superabsorbent resin may be adversely affected.

The method of preparing the superabsorbent resin particles by thermal polymerization or photopolymerization of such a monomer composition is not limited as long as it is a commonly used polymerization method. Specifically, the polymerization method is divided into thermal polymerization and photopolymerization depending on a polymerization energy source. In general, when thermal polymerization is carried out, the polymerization can proceed in a reactor having an agitating axis such as a kneader, But the polymerization method described above is only one example, and the present invention is not limited to the polymerization method described above.

For example, as described above, the superabsorbent resin particles obtained by supplying hot air or heating the reactor to a reactor such as a kneader equipped with a stirring shaft and thermally polymerizing the same, The superabsorbent resin particles discharged into the discharge port may be in the form of several centimeters to several millimeters. Specifically, the size of the superabsorbent resin particles to be obtained may vary depending on the concentration of the monomer composition to be injected, the injection rate, etc. Usually, superabsorbent resin particles having a particle size of 2 to 50 mm can be obtained.

Further, when photopolymerization proceeds in a reactor equipped with a movable conveyor belt as described above, the shape of the superabsorbent resin particles usually obtained may be superabsorbent resin particles on a sheet having a belt width. At this time, the thickness of the polymer sheet depends on the concentration and the injection rate of the monomer composition to be injected, but it is preferable to supply the monomer composition so that a polymer in the form of a sheet having a thickness of usually 0.5 to 5 cm can be obtained. When the monomer composition is supplied to such an extent that the thickness of the polymer in the sheet is too thin, the production efficiency is low, which is undesirable. When the thickness of the polymer on the sheet exceeds 5 cm, the polymerization reaction proceeds unevenly due to the excessively thick thickness, The physical properties of the resin can be adversely affected.

Thereafter, the method for producing a superabsorbent resin according to the present invention is carried out by b) drying the hydrogel polymer.

The normal water content of the hydrogel polymer obtained in the step a) is 30 to 60% by weight. The term "water content" as used throughout the present specification means a value obtained by subtracting the weight of the hydrogel polymer from the weight of the hydrogel polymer in terms of the content of water to the total weight of the functional gel polymer (specifically, In the drying process, the temperature is raised from 180 ° C to 180 ° C, and then maintained at 180 ° C. In this case, Drying time is set to 20 minutes including 5 minutes of temperature rise step, and water content is measured.)

The hydrogel polymer obtained in the step a) is subjected to a drying step, and preferably the drying temperature of the drying step may be 150 ° C to 250 ° C. On the other hand, throughout the present specification, the "drying temperature" can be defined as the temperature of the heating medium supplied for drying or the temperature of the drying reactor including the heating medium and the polymer in the drying process.

If the drying temperature is lower than 150 ° C, the drying time becomes excessively long and the physical properties of the superabsorbent resin to be finally formed may deteriorate. When the drying temperature exceeds 250 ° C, only the polymer surface is excessively dried, And the physical properties of the finally formed superabsorbent resin may be deteriorated. Preferably, the drying can be carried out at a temperature of 150 ° C to 250 ° C, more preferably at a temperature of 160 ° C to 200 ° C.

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

The drying method of the drying step may also be selected and used without limitation of its structure as long as it is usually used as a drying step of the hydrogel polymer. Specifically, the drying step can be carried out by hot air supply, infrared irradiation, microwave irradiation, ultraviolet irradiation, or the like. The water content of the polymer after such a drying step may be 0.1 to 10% by weight.

Meanwhile, in order to increase the efficiency of the drying step, the method of manufacturing the super absorbent polymer according to the present invention may further include a step of simply pulverizing, if necessary, before the drying step. The step of simply pulverizing before the drying step may be carried out such that the particle size of the polymer of the superabsorbent resin particles is 1 mm to 15 mm. However, pulverizing the polymer so that the particle size of the polymer is less than 1 mm, And further, there may be a phenomenon of agglomeration among the pulverized particles, and when the pulverization is carried out so as to have a particle size exceeding 15 mm, the effect of increasing the efficiency of the subsequent drying step due to pulverization becomes insignificant.

The pulverizer used in the simple pulverizing step prior to the drying step is not limited in its constitution, but may be a vertical pulverizer, a turbo cutter, a turbo grinder, A crusher consisting of a rotary cutter mill, a cutter mill, a disc mill, a shred crusher, a crusher, a chopper and a disc cutter And a device group. However, the present invention is not limited to the above-described examples.

When the step of pulverizing is carried out in order to increase the drying efficiency before the drying step, a phenomenon of sticking to the surface of the pulverizer may occur due to the polymer having a high water content. Therefore, in order to increase the efficiency of the pulverization step before drying of the hydrogel polymer, an additive capable of preventing sticking at the time of pulverization can be further used. Specific examples of usable additives include, but are not limited to, an anti-aggregation inhibitor such as steam, water, a surfactant, an inorganic powder such as Clay or Silica, and the like; A crosslinking agent comprising a hydroxyl group-containing initiator, an azo-based initiator, an azo-based initiator, hydrogen peroxide and a thermal polymerization initiator such as ascorbic acid, an epoxy crosslinking agent, a diol crosslinking agent, an acrylate of a bifunctional group or a polyfunctional group having three or more functional groups, But it is not limited to the examples described above.

Thereafter, in the method for producing a superabsorbent resin according to the present invention, after the above-mentioned drying step, c) the dried hydrogel polymer is pulverized to obtain superabsorbent resin particles. The particle size of the superabsorbent resin particles obtained after the pulverization step is 150 to 850 탆. In the method for producing a superabsorbent resin according to the present invention, the pulverizer used for pulverizing to such a particle size is specifically a pin mill, a hammer mill, a screw mill, a roll mill a roll mill, a disc mill or a jog mill may be used, but the present invention is not limited thereto.

Thereafter, the method for producing a superabsorbent resin according to the present invention comprises the steps of: d) mixing the superabsorbent resin particles with particles having a particle size of less than 150 μm, particles having a particle size of 150 μm or more and less than 300 μm, particles having a particle size of 300 μm or more and less than 450 μm, A particle having a particle size of less than 600 mu m, a particle having a particle size of 600 mu m or more and 850 mu m or less, and a particle having a particle size of 850 mu m or more. In this case, the particle size as a classification standard may be based on the specific surface area ratio per weight of the polymer particles. The larger the value in the classification step, the more advantageous the distribution of the crosslinking agent added to the polymer particles can be made more uniform when the crosslinking agent is added. Therefore, in consideration of the uniformity of the added cross-linking agent and the economical efficiency of the process, the method for producing a superabsorbent resin according to the present invention is preferably carried out by using particles having a particle size of less than 150 탆, particles having a particle size of not less than 150 탆 and less than 300 탆, Particles having a particle size of not less than 450 탆 and less than 600 탆, particles having a particle size of not less than 600 탆 and not more than 850 탆, and particles having a particle size of not less than 850 탆.

The preparation process of the classification step will be described in detail. The superabsorbent resin particles supplied from the polymer feeder are pulverized in a polymer grinder at a particle size of 150 to 850 μm, and classified through a classifier according to each particle size. At this time, the fine particles having a particle size of less than 150 占 퐉 are not separately classified, but particles having a particle size exceeding 850 占 퐉 are classified separately and can be sent back to the crusher.

Thereafter, the method for producing a superabsorbent resin according to the present invention comprises the steps of: e) normal particles comprising superabsorbent resin particles having a particle size of 150 to 850 탆; And

50 to 200 parts by weight of superabsorbent resin particles having a particle size of 150 mu m or less and 100 parts by weight of water of the superabsorbent resin particles having a particle size of 150 mu m or less and 0.1 to 30 parts by weight of an additive per 100 parts by weight of the superabsorbent resin particles having a particle size of 150 mu m or less Absorbing resin particles, which are prepared by mixing a re-agglomerated re-agglomerated body and a re-agglomerated body.

More specifically, the process of re-assembling the fine pulverulent assembly includes 50 to 200 parts by weight of superabsorbent resin particles having a particle size of 150 mu m or less, water to 100 parts by weight of the superabsorbent resin particles having a particle size of 150 mu m or less, By weight based on 100 parts by weight of the superabsorbent resin particles.

In the method for producing a superabsorbent resin according to the present invention, the monomer composition may contain a fine powder of the prepared superabsorbent resin powder, that is, a certain amount of polymer or resin powder having a particle size of less than 150 μm Specifically, it is possible to add a polymer or a resin powder having a particle size of less than 150 μm at the initial, middle, and late stages of the monomer composition before or after the polymerization reaction. There is no limitation on the amount that can be added at this time, but it is preferable to add 1 to 20 parts by weight based on 100 parts by weight of the monomer contained in the monomer resin composition in order to prevent deterioration of physical properties of the superabsorbent resin to be finally produced.

When re-assembling the fine particle-dispersed assembly, the particle size is preferably 150 탆 or less, more preferably 20 to 100 탆.

Water is contained in an amount of 50 to 200 parts by weight based on 100 parts by weight of the superabsorbent resin particles having a particle size of 150 탆 or less to produce a fine pulverized material. When water is contained in an amount of less than 50 parts by weight, fine pulverization is incompletely carried out, If a large amount of fine powder is generated and the water is contained in an amount exceeding 200 parts by weight, the cohesive force remains the same and the load of the mechanical load and the drying may be caused by the amount of the added water.

The amount of the additive is preferably 0.1 to 30 parts by weight, more preferably 0.5 to 20 parts by weight, and more preferably 1 to 15 parts by weight, based on 100 parts by weight of the superabsorbent resin particles having a particle size of 150 탆 or less. desirable. When the additive is included in the above range, it is possible to produce a uniform finely divided assembly by controlling the absorption depth and the absorption rate. When the additive is contained in an amount of less than 0.1 part by weight, the added effect is hardly exhibited. When the additive is contained in an amount exceeding 30 parts by weight, further improvement of physical properties can not be expected, and the physical properties of the superabsorbent resin have.

The additive added in the method for producing a superabsorbent resin according to the present invention is not limited in its constitution as long as it is a compound capable of reacting with the functional group possessed by the polymer. Specifically, a substance having a reactive group (functional group) capable of reacting with a carboxylic acid (COO-) group present in the superabsorbent resin can improve the strength of the fine particle assembly and reduce the re-crushing ratio. In addition, the water absorption rate of the fine particles can be controlled simultaneously.

In order to improve the properties of the resulting superabsorbent resin, the polyhydric alcohol compound; Epoxy compounds; Polyamine compounds; Halo epoxy compounds; A condensation product of a haloepoxy compound; Oxazoline compounds; Mono-, di- or polyoxazolidinone compounds; Cyclic urea compounds; Alkylene carbonate compounds; And a water-soluble polymer material having a reactive group capable of reacting with a carboxylic acid.

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

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

As the haloepoxy compound, epichlorohydrin, epibromohydrin, and? -Methyl epichlorohydrin can be used. On the other hand, as the mono-, di- or polyoxazolidinone compounds, for example, 2-oxazolidinone and the like can be used. As the alkylene carbonate compound, ethylene carbonate and the like can be used.

The water-soluble polymer material having a reactive group capable of reacting with a carboxylic acid may be selected from the group consisting of water-soluble polymer materials having a number average molecular weight of 1,000 or more. Specifically, examples of the water-soluble polymer material having a number average molecular weight of 1,000 or more include starch, polyacrylic acid, polyvinyl alcohol, polyethylene glycol, and carboimide polymer compounds.

The additive may be any one selected from the group consisting of a material containing at least one reactive group capable of reacting with the carboxylic acid of the superabsorbent resin. All of the above-mentioned materials have a functional group capable of reacting with a carboxylic acid, and when a polymer having a functional group that reacts with a carboxylic acid is used, the fine powder reacts with the polymer to form a chemical bond, Strength) can be ensured.

At this time, the constitution of the method of adding the additive to the fine powder is not limited. A method in which the additive and the fine powder are put into a reaction tank and mixed, or the additive is sprayed onto the fine powder, and a method in which the fine powder and the additive are continuously supplied and mixed in a reaction vessel such as a continuously operated mixer. In this case, the additive may be used alone or in a diluted solvent.

In the above step, the normal particles refer to superabsorbent resin particles in which particles having a size of 600 to 850 μm, particles having a size of 300 to 600 μm, and particles having a size of 150 to 300 μm are mixed, Means that the particles are re-assembled using particles having a size of 150 mu m or less.

In addition, the method for producing a superabsorbent resin according to the present invention may further comprise a step of drying and pulverizing the pulverized re-assembly after re-assembling the pulverized re-assembly in step e).

The drying of the re-assembled finely divided assembly may be performed at a temperature of 150 to 250 ° C for 20 to 90 minutes.

The above-mentioned means for raising the temperature for drying is not limited in its constitution. Specifically, the heating medium can be supplied or heated directly by means such as electricity, but the present invention is not limited to the above-described examples. Specific examples of the heat source that can be used include steam, electricity, ultraviolet rays, and infrared rays, and heated heat fluids and the like may also be used.

The re-assembled fine aggregate assembly of the superabsorbent resin produced by the method of the present invention is characterized in that the granules having a particle size of 150 to 850 μm after drying and grinding are contained in an amount of 60% by weight or more.

The high proportion of particles having a particle size of 150 to 850 mu m in the fine pulverulent assembly indicates that the reassembly is firmly carried out (cohesive force is high). In the above, the pulverulent pulverization uses superabsorbent resin particles having a particle size of 150 mu m or less The particles are classified into particles having a particle size of 150 탆 or less, particles having a particle size of 150 탆 to 850 탆 and particles having a particle size of 850 탆 or more by repeatedly drying and pulverizing and classifying the re-assembled fine particle dispersion.

In addition, the fine pulverized reassembly of the superabsorbent resin is characterized in that the water content after drying and pulverization is 2.5% by weight or less.

Further, the present invention can provide a superabsorbent resin produced by the above-described method for producing a superabsorbent resin.

The present invention also relates to a solid particle comprising superabsorbent resin particles having a particle size of 150 to 850 탆; And

50 to 200 parts by weight of superabsorbent resin particles having a particle size of 150 mu m or less and 100 parts by weight of water of the superabsorbent resin particles having a particle size of 150 mu m or less and 0.1 to 30 parts by weight of an additive per 100 parts by weight of the superabsorbent resin particles having a particle size of 150 mu m or less By mass of the water-absorbent resin, and re-assembling the mixture.

More specifically, the superabsorbent resin-containing superabsorbent resin-containing particles may contain 30 parts by weight or less, more preferably 30 parts by weight or less, based on 100 parts by weight of the normal particles and the fine aggregate, 20 parts by weight or less.

In the superabsorbent resin, the additive may be a polyhydric alcohol compound; Epoxy compounds; Polyamine compounds; Halo epoxy compounds; A condensation product of a haloepoxy compound; Oxazoline compounds; Mono-, di- or polyoxazolidinone compounds; Cyclic urea compounds; Alkylene carbonate compounds; And a water-soluble polymer material having a reactive group capable of reacting with a carboxylic acid.

Further, the additive may be any one selected from the group consisting of a material containing at least one reactant capable of reacting with the carboxylic acid of the superabsorbent resin.

The water-soluble polymer material having a reactive group capable of reacting with the carboxylic acid may be at least one selected from the group consisting of water-soluble polymer materials having a number average molecular weight of 1,000 or more. Examples thereof include starch, polyacrylic acid, Polyvinyl alcohol, polyethyleneglycol, and a carboimide-based polymer compound.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the embodiments of the present invention described below are illustrative only and the scope of the present invention is not limited to these embodiments. The scope of the present invention is indicated in the claims, and moreover, includes all changes within the meaning and range of equivalency of the claims. In the following Examples and Comparative Examples, "%" and "part" representing the content are on a mass basis unless otherwise specified.

Manufacturing example  1: Preparation of superabsorbent resin particles

100 g of acrylic acid, 0.5 g of polyethylene glycol diacrylate as a crosslinking agent, 38.9 g of caustic soda (NaOH) and 103.9 g of water were mixed to prepare a monomer composition having a monomer concentration of 50% by weight.

Then, 0.01 g of Irgacure 651 and 0.3 g of sodium persulfate were mixed in the above monomer composition, and the mixture was supplied through a rotating belt polymerizer and ultraviolet rays were irradiated. Polymerization was started within 1 minute after irradiation with ultraviolet rays, and polymerization was continued for 5 minutes. At this time, the internal temperature of the reactor was 80 to 99 ° C. The polymerized superabsorbent resin particles were transferred to a cutter and cut.

Thereafter, the polymer discharged from the cutter was dried in a hot-air drier at 180 캜 for 1 hour. Next, after being pulverized by a pin-mill grinder, particles having a particle size of less than 150 占 퐉, particles having a particle size of not less than 150 占 퐉 and less than 300 占 퐉, particles having a particle size of not less than 300 占 퐉 and less than 450 占 퐉, particles having a particle size of not less than 450 占 퐉 and not more than 600 占 퐉, And particles having a particle size of 600 μm or more and 850 μm or less and 850 μm or more.

Example : Differential Reassembly  Produce

In the preparation of the superabsorbent resin, the reassembly was made by the following method.

Comparative Example 1

100 g of a fine powder having a particle size of 150 탆 or less was charged into a high-speed mixer and simultaneously an equal amount of water was added to prepare a fine powder compact. The temperature of the introduced water was room temperature and the residence time of the mixer was 3 minutes. The reassembly thus produced was dried for 1 hour using a hot air drier at a temperature of 180 DEG C and pulverized with a pin mill, and then sieved to obtain particles having a particle size of less than 150 mu m, particles having a particle size of 150 mu m or more and less than 300 mu m, Particles having a particle size of not less than 450 μm and not more than 600 μm, and particles having a particle size of not less than 600 μm and not more than 850 μm and not less than 850 μm.

Example 1

A finely divided product was obtained in the same manner as in Comparative Example 1, except that 10% by weight of 1,3-propanediol was added as an additive to water used as a solvent for making a fine pulverulent assembly.

Example  2

A fine pulverized product was obtained in the same manner as in Comparative Example 1, except that 10 wt% of poly ethylene glycol was added as an additive to water used as a solvent for making the pulverized re-assembly.

Example  3

A finely divided product was obtained by proceeding in the same manner as in Comparative Example 1, except that 10% by weight of carbodilite V-02 was added as an additive to water used as a solvent for making a fine pulverulent assembly.

Experimental Example : Property evaluation

In order to evaluate the physical properties of the pulverized re-assembly, the pulverized pulverized pulverized pulverized pulverized pulverized pulverized pulverized pulverized pulverized pulverized pulverized pulverized pulverized pulverized pulverized pulverized pulverized pulverized pulverized pulverized pulverized pulverized pulverized pulverized pulverized pulverized pulverized pulverized pulverized pulverized pulverized pulverized pulverized pulverized pulverized pulverized pulverized pulverized pulverized pulverized pulverized pulverized.

The properties were measured as follows, and the results are shown in Table 1.

After reassembly
Before drying
Particle uniformity Grain size after dry grinding
(Ratio of 150 to 850 mu m) after drying
Moisture content Comparative Example 1 Poor 52% 2.7% Example 1 Excellent 63% 2.3% Example 2 Excellent 73% 1.7% Example 3 Excellent 75% 1.6%

As shown in Table 1, it can be seen that Examples 1 to 3 exhibit a uniform distribution of particles before re-assembly, as compared with Comparative Example 1. Further, in the superabsorbent resin of Examples 1 to 3 of the present invention, after the fine pulverized material was dried and pulverized, particles having a particle size of 150 to 850 占 퐉 were contained in an amount of 60% by weight or more and the moisture content after drying and pulverization was 2.5% In comparison with Comparative Example 1, it can be seen that the superabsorbent resin of the present invention is more uniform than the conventional superabsorbent resin by controlling the depth of absorption and the rate of absorption by using the additive during the fine granulation reassembling It was confirmed from the above results that the fine aggregate can be prepared and the cohesive force can be improved through reaction with the superabsorbent resin particles.

Claims (23)

Normal particles comprising superabsorbent resin particles having a particle size of 150 to 850 탆; And
50 to 200 parts by weight of superabsorbent resin particles having a particle size of 150 mu m or less and 100 parts by weight of water of the superabsorbent resin particles having a particle size of 150 mu m or less and 0.1 to 30 parts by weight of an additive per 100 parts by weight of the superabsorbent resin particles having a particle size of 150 mu m or less By weight of the fine aggregate, and mixing the re-assembled finely divided product. The method according to claim 1,
Characterized in that the superabsorbent resin-containing superabsorbent resin comprises 30 parts by weight or less of the fine pulverulent reassembly with respect to 100 parts by weight of the normal particles based on the total weight of the normal particles and the fine pulverulent subassembly. A method for producing a resin. The method for producing a superabsorbent resin-containing superabsorbent resin according to claim 1,
a) preparing a hydrogel polymer by thermal polymerization or photopolymerization of a monomer composition comprising a water-soluble ethylenically unsaturated monomer and a polymerization initiator;
b) drying the hydrogel polymer;
c) pulverizing the dried hydrous gel polymer to obtain superabsorbent resin particles;
d) Particles having a particle size of less than 150 탆, particles having a particle size of 150 탆 or more and less than 300 탆, particles having a particle size of 300 탆 or more and less than 450 탆, particles having a particle size of not less than 450 탆 and less than 600 탆, And particles having a particle size of 850 탆 or more; And
e) normal particles comprising the superabsorbent resin particles having a particle size of 150 to 850 탆; And
50 to 200 parts by weight of superabsorbent resin particles having a particle size of 150 mu m or less and 100 parts by weight of water of the superabsorbent resin particles having a particle size of 150 mu m or less and 0.1 to 30 parts by weight of an additive per 100 parts by weight of the superabsorbent resin particles having a particle size of 150 mu m or less Absorbent resin particles comprising a finely divided water-absorbent resin-containing fine particle-dispersed resin particle prepared by mixing a re-assembled fine particle-dispersion material. The method of claim 3,
Further comprising the step of drying and pulverizing the fine pulverization product after re-assembling the pulverization product in step (e). The method of claim 3,
Wherein in the step (e), the reassembled fine aggregate assembly is reassembled using particles of superabsorbent resin having a particle size of 150 mu m or less. The method according to claim 1,
The additive may be a polyhydric alcohol compound; Epoxy compounds; Polyamine compounds; Halo epoxy compounds; A condensation product of a haloepoxy compound; Oxazoline compounds; Mono-, di- or polyoxazolidinone compounds; Cyclic urea compounds; Alkylene carbonate compounds; And a water-soluble polymer material having a reactive group capable of reacting with a carboxylic acid. The method according to claim 1,
Wherein the additive is at least one selected from the group consisting of a material containing at least one reactive group capable of reacting with the carboxylic acid of the superabsorbent resin. The method of claim 6,
Wherein the water-soluble polymer material having a reactive group capable of reacting with the carboxylic acid is at least one selected from the group consisting of water-soluble polymer materials having a number average molecular weight of 1,000 or more. The method of claim 8,
The water-soluble polymer material having a number average molecular weight of 1000 or more may be a starch, polyacrylic acid, Wherein the polymer is at least one selected from the group consisting of polyvinyl alcohol, polyethyleneglycol, and carboimide-based polymer compounds. The method of claim 3,
Characterized by further comprising the step of pulverizing the superabsorbent resin particles to a particle size of 1 mm to 15 mm before the drying step of the step b). The method of claim 3,
Wherein the drying step of step b) is carried out at a temperature of 150 ° C to 250 ° C. The method of claim 4,
Wherein the step of drying the fine pulverulent assembly is carried out at a temperature of 150 ° C to 250 ° C. The method of claim 4,
Wherein the step of drying the finely divided assembly is carried out for 20 minutes to 90 minutes. The method of claim 4,
Wherein the step of drying the fine pulverulent assembly is carried out by heating at least one selected from the group consisting of steam, electricity, ultraviolet rays and infrared rays, and drying. The method according to claim 1,
Wherein the re-assembled fine aggregate of the superabsorbent resin comprises 60 wt% or more of particles having a particle size of 150 to 850 μm after drying and pulverization. The method according to claim 1,
Wherein the re-assembled fine aggregate of the superabsorbent resin has a moisture content of 2.5% or less after drying and pulverization. A superabsorbent resin produced by the method for producing a superabsorbent resin according to any one of claims 1 to 16. Normal particles comprising superabsorbent resin particles having a particle size of 150 to 850 탆; And
50 to 200 parts by weight of superabsorbent resin particles having a particle size of 150 mu m or less and 100 parts by weight of water of the superabsorbent resin particles having a particle size of 150 mu m or less and 0.1 to 30 parts by weight of an additive per 100 parts by weight of the superabsorbent resin particles having a particle size of 150 mu m or less By weight of a finely divided resin, and re-assembling the mixture. [19] The method according to claim 18, wherein the superabsorbent resin-containing superabsorbent resin comprises 30 parts by weight or less of the fine pulverulent reassembly with respect to 100 parts by weight of the normal particles, based on the total weight of the normal particles and the fine pulverulent subassembly By weight. 19. The method of claim 18, wherein the additive is selected from the group consisting of a polyhydric alcohol compound; Epoxy compounds; Polyamine compounds; Halo epoxy compounds; A condensation product of a haloepoxy compound; Oxazoline compounds; Mono-, di- or polyoxazolidinone compounds; Cyclic urea compounds; Alkylene carbonate compounds; And a water-soluble polymer material having a reactive group capable of reacting with a carboxylic acid. 19. The method of claim 18,
Wherein the additive is at least one selected from the group consisting of a material containing at least one of reactants capable of reacting with the carboxylic acid of the superabsorbent resin. The method of claim 20,
Wherein the water-soluble polymer material having a reactive group capable of reacting with the carboxylic acid is at least one selected from the group consisting of water-soluble polymer materials having a number average molecular weight of 1,000 or more. 23. The method of claim 22,
The water-soluble polymer material having a number average molecular weight of 1000 or more may be a starch, polyacrylic acid, Wherein the polymer is at least one selected from the group consisting of polyvinyl alcohol, polyethyleneglycol, and carboimide-based polymer compounds.