WO2021117784A1 - 被覆樹脂粒子の製造方法及び粒子表面積の調整方法 - Google Patents

被覆樹脂粒子の製造方法及び粒子表面積の調整方法 Download PDF

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WO2021117784A1
WO2021117784A1 PCT/JP2020/045930 JP2020045930W WO2021117784A1 WO 2021117784 A1 WO2021117784 A1 WO 2021117784A1 JP 2020045930 W JP2020045930 W JP 2020045930W WO 2021117784 A1 WO2021117784 A1 WO 2021117784A1
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water
resin particles
absorbent resin
mass
substance
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PCT/JP2020/045930
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English (en)
French (fr)
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大輝 澤木
建太郎 佐野
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住友精化株式会社
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Priority to JP2021564013A priority Critical patent/JP7344313B2/ja
Publication of WO2021117784A1 publication Critical patent/WO2021117784A1/ja

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    • A61F13/15—Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators
    • A61F13/53—Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators characterised by the absorbing medium
    • A61F2013/530481—Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators characterised by the absorbing medium having superabsorbent materials, i.e. highly absorbent polymer gel materials
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J2333/00—Characterised by the use of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides, or nitriles thereof; Derivatives of such polymers
    • C08J2333/02—Homopolymers or copolymers of acids; Metal or ammonium salts thereof

Definitions

  • the present invention relates to a method for producing coated resin particles and a method for adjusting the surface area of particles.
  • Water-absorbent resin particles are widely used in various fields such as sanitary materials such as disposable diapers, sanitary products, and simple toilets; agricultural and horticultural materials such as water retention agents and soil conditioners; and industrial materials such as water stop agents and dew condensation inhibitors. ing.
  • the water-absorbent resin particles are required to control various performances such as water absorption rate (see, for example, Patent Document 1 below).
  • the present inventors have focused on adjusting the particle surface area as a method of controlling various performances such as water absorption rate, and can adjust the particle surface area by a method different from the method of adjusting the production conditions of the water-absorbent resin particles. It was found that the surface area of particles can be increased.
  • One aspect of the present invention is to provide a method for producing coated resin particles capable of increasing the surface area of particles.
  • Another aspect of the present invention is to provide a method for adjusting the particle surface area in which the particle surface area can be easily adjusted.
  • One aspect of the present invention is to polymerize a first substance and a second substance that polymerizes with the first substance on the surface of the water-absorbent resin particles in a water-absorbing state to at least the water-absorbent resin particles.
  • a method for producing coated resin particles which comprises a coating step of obtaining a coated portion to be partially coated.
  • the water-absorbent resin particles are obtained by polymerizing a first substance and a second substance that polymerizes with the first substance on the surface of water-absorbent resin particles in a water-absorbing state.
  • Particle surface area that adjusts the surface areas of the water-absorbent resin particles and the coated resin particles having the coating portion based on the degree of expansion of the water-absorbent resin particles in the water-absorbing state in the coating step of obtaining a coating portion that covers at least a part of the above. Provides an adjustment method for.
  • each component in the composition means the total amount of the plurality of substances present in the composition when a plurality of substances corresponding to each component are present in the composition, unless otherwise specified.
  • a first substance and a second substance that polymerizes with the first substance are polymerized on the surface of water-absorbent resin particles (coated body) in a water-absorbing state.
  • a coating step of reacting to obtain a coating portion that covers at least a part of the water-absorbent resin particles is provided.
  • the method for producing coated resin particles according to the present embodiment at least a part of the water-absorbent resin particles (coated body) is coated with a coating portion which is a polymerization reaction product of the first substance and the second substance.
  • a coating portion which is a polymerization reaction product of the first substance and the second substance.
  • the surface area of the coated resin particles can be increased by adjusting the degree of expansion of the water-absorbent resin particles in the water-absorbing state in the coating step.
  • the surface area of coated resin particles having a particle diameter of, for example, 300 to 400 ⁇ m can be increased.
  • the present inventor has found the following findings.
  • the particle surface area is not fixed. Therefore, as the particles shrink, the particle surface area changes greatly depending on the state of the particles, so that the particles shrink. It is difficult to adjust the particle surface area based on the state of the previous water-absorbent resin particles.
  • the surface area of the particles is fixed by the coating portion, so that the surface area of the particles does not easily change significantly before and after shrinkage when the particles shrink.
  • the surface area of the water-absorbent resin particles before shrinkage can be easily adjusted according to the degree of expansion of the water-absorbent resin particles. Therefore, the surface area of the coated resin particles can be easily adjusted by adjusting the degree of expansion of the water-absorbent resin particles in the manufacturing process of the coated resin particles having the coated portion, and the surface area of the coated resin particles can be increased.
  • coated resin particles can be obtained.
  • the coated resin particles include water-absorbent resin particles and a coating portion that covers at least a part of the water-absorbent resin particles.
  • the shape of the water-absorbent resin particles to be coated is not particularly limited, and may be, for example, substantially spherical, indefinite, granular, or the like, and may be a shape in which primary particles having these shapes are aggregated.
  • the amorphous water-absorbent resin particles can be obtained, for example, by crushing the resin mass with a crusher.
  • the water-absorbent resin particles are not particularly limited as long as they are composed of a water-absorbent resin.
  • the water absorption amount (water absorption amount under normal pressure) of ion-exchanged water at 25 ° C. in the water-absorbent resin particles may be, for example, 10 g / g or more.
  • the water-absorbent resin particles can contain, for example, a crosslinked polymer obtained by polymerizing a monomer containing an ethylenically unsaturated monomer. That is, the water-absorbent resin particles can have a structural unit derived from the ethylenically unsaturated monomer, and can include a crosslinked polymer having a structural unit derived from the ethylenically unsaturated monomer. ..
  • Examples of the polymerization method of the ethylenically unsaturated monomer include a reverse phase suspension polymerization method, an aqueous solution polymerization method, a bulk polymerization method, and a precipitation polymerization method.
  • the ethylenically unsaturated monomer may be a water-soluble ethylenically unsaturated monomer (for example, an ethylenically unsaturated monomer having a solubility in 100 g of ion-exchanged water at 25 ° C. of 1 g or more).
  • examples of the ethylenically unsaturated monomer include (meth) acrylic acid and its salt, 2- (meth) acrylamide-2-methylpropanesulfonic acid and its salt, (meth) acrylamide, N, N-dimethyl (meth) acrylamide.
  • 2-Hydroxyethyl (meth) acrylate, N-methylol (meth) acrylamide, polyethylene glycol mono (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, N, N-diethylaminopropyl (meth) acrylate, diethylaminopropyl (Meta) acrylamide and the like can be mentioned.
  • the amino group may be quaternized.
  • the ethylenically unsaturated monomer may contain at least one selected from the group consisting of (meth) acrylic acid and salts thereof from the viewpoint of easily adjusting (easily increasing) the surface area of the coated resin particles.
  • the water-absorbent resin particles preferably have a structural unit derived from at least one selected from the group consisting of (meth) acrylic acid and salts thereof, from the viewpoint of easily adjusting (easily increasing) the surface area of the coated resin particles. ..
  • the acidic group may be neutralized before use in the polymerization reaction.
  • the degree of neutralization in the ethylenically unsaturated monomer may be 10 to 100 mol%, 50 to 90 mol%, or 60 to 80 mol% of the acidic group in the ethylenically unsaturated monomer.
  • a monomer other than the above-mentioned ethylenically unsaturated monomer may be used.
  • Such a monomer can be used, for example, by mixing with an aqueous solution containing the above-mentioned ethylenically unsaturated monomer.
  • the amount of the ethylenically unsaturated monomer used should be the total amount of the monomer (the total amount of the monomer for obtaining the water-absorbent resin particles. For example, the total amount of the monomer giving the structural unit of the crosslinked polymer. The same shall apply hereinafter). On the other hand, it is preferably 70 to 100 mol%.
  • the ratio of (meth) acrylic acid and a salt thereof is more preferably 70 to 100 mol% with respect to the total amount of the monomers.
  • “Ratio of (meth) acrylic acid and its salt” means the ratio of the total amount of (meth) acrylic acid and its salt.
  • the water-absorbent resin particles containing a crosslinked polymer having a structural unit derived from the ethylenically unsaturated monomer and the above-mentioned ethylenically unsaturated monomer.
  • it contains at least one selected from the group consisting of (meth) acrylic acid and a salt thereof, and the ratio of the (meth) acrylic acid and a salt thereof is the total amount of the monomer for obtaining the water-absorbent resin particles (for example, It is possible to provide water-absorbent resin particles in an amount of 70 to 100 mol% based on the total amount of the monomers giving the structural unit of the crosslinked polymer.
  • Cross-linking by self-cross-linking may occur during polymerization, but cross-linking may be promoted by using an internal cross-linking agent.
  • an internal cross-linking agent When an internal cross-linking agent is used, it is easy to control the water absorption characteristics of the water-absorbent resin particles.
  • the internal cross-linking agent include (poly) ethylene glycol diglycidyl ether, (poly) propylene glycol diglycidyl ether, (poly) glycerin diglycidyl ether, (poly) glycerin triglycidyl ether, (poly) propylene glycol polyglycidyl ether, and poly.
  • examples thereof include polyglycidyl compounds such as glycerol polyglycidyl ether; divinyl-based compounds; dialcohol-based compounds; and diacrylate-based compounds.
  • the water-absorbent resin particles may be composed of only crosslinked polymer particles, but may further contain, for example, a gel stabilizer, a metal chelating agent, a fluidity improver (lubricant), and the like. These components may be located inside the crosslinked polymer particles, on the surface of the crosslinked polymer particles, or both.
  • the covering portion is a polymerization reaction product of the above-mentioned first substance and the second substance.
  • the coating may be water-soluble and may not be water-soluble (may be poorly water-soluble).
  • the solubility of the coating portion may be, for example, 1 g or more (for example, 1 to 150 g) with respect to 100 g of ion-exchanged water at 25 ° C.
  • the constituent material of the coating is a step-growth polymerization reaction product such as urethane resin, phenol resin (for example, a condensate of a phenol compound and aldehyde), polyester, polyamide, polycarbonate, etc .; polyvinyl alcohol, polyacrylamide, polyalkylene oxide, polyalkylene glycol. It may contain a chain polymerization reaction product such as.
  • the first substance and the second substance may be different or the same.
  • the medium particle size of the coated resin particles according to this embodiment may be in the following range.
  • the medium particle size of the coated resin particles may be 100 ⁇ m or more, 150 ⁇ m or more, 200 ⁇ m or more, 250 ⁇ m or more, 300 ⁇ m or more, 350 ⁇ m or more, 355 ⁇ m or more, 360 ⁇ m or more, 380 ⁇ m or more, 400 ⁇ m or more, or 410 ⁇ m or more.
  • the medium particle size of the coated resin particles may be 800 ⁇ m or less, 700 ⁇ m or less, 600 ⁇ m or less, 500 ⁇ m or less, 450 ⁇ m or less, 410 ⁇ m or less, 400 ⁇ m or less, 380 ⁇ m or less, 360 ⁇ m or less, or 355 ⁇ m or less. From these viewpoints, the medium particle size of the coated resin particles may be 100 to 800 ⁇ m, 150 to 700 ⁇ m, 200 to 600 ⁇ m, or 250 to 500 ⁇ m.
  • FIG. 1 is a schematic cross-sectional view showing an example of coated resin particles.
  • the coated resin particles 1 shown in FIG. 1 have a resin particles 1a and a coating layer (coating portion) 1b that covers at least a part of the surface of the resin particles (water-absorbent resin particles) 1a.
  • the entire surface of the resin particles 1a is covered with the coating layer 1b.
  • the coating layer 1b dissolves and disappears, so that the behavior of bringing the resin particles 1a into contact with water (for example, change with time) can be adjusted.
  • the coating amount of the coating layer 1b on the surface of the resin particles 1a the contact amount of the resin particles 1a with water can be adjusted.
  • the first substance and the second substance that polymerizes with the first substance are polymerized on the surface of the water-absorbent resin particles in a water-absorbing state. ..
  • the first substance and the second substance can be brought into contact with each other on the surface of the water-absorbent resin particles.
  • the polymerization reaction in the coating step is preferably a step-growth polymerization reaction or a chain polymerization reaction, and more preferably a step-growth polymerization reaction from the viewpoint that it is presumed that agglomeration of particles is unlikely to occur.
  • the step-growth polymerization reaction since the polymerization initiator is not required for the polymerization reaction, it is difficult for the polymerization initiator to appear on the particle surface, and the surface area of the coated resin particles is particularly easy to adjust (easily increase). I'm guessing.
  • the reaction temperature of the step-growth polymerization reaction between the first substance and the second substance may be, for example, 15 to 200 ° C.
  • the degree of expansion of water-absorbent resin particles in the water-absorbing state in the coating process (mass-based expansion degree. Mass of water-absorbent resin particles in water-absorbing state / net content of water-absorbent resin particles (mass of water-absorbent resin particles in dry state)) ,
  • the range may be as follows.
  • the degree of expansion is 1.5 times or more, 1.75 times or more, 2.0 times or more, 2.1 times or more, 2.5 times or more, 2.75 times or more, 3.0 times or more, or 3. It may be double or more.
  • the degree of expansion may be 5 times or less, 4.5 times or less, 4.0 times or less, or 3.5 times or less. As the degree of expansion, the degree of expansion at 25 ° C. can be used.
  • the degree of expansion of the water-absorbent resin particles in the water-absorbing state the degree of expansion at the time when the first substance and the second substance come into contact (polymerization reaction) can be used.
  • the degree of expansion of the water-absorbent resin particles and the second substance can be used.
  • the degree of expansion at the time of supplying the second substance can be used.
  • the degree of expansion can be adjusted to a desired value by adjusting the water content contained in the water-absorbent resin particles to be coated, the amount of the solvent contained in the solution containing the first substance as a solute, and the like.
  • Combinations of the first and second substances include polyols and polyisocyanates; aldehydes and phenolic compounds; polyols and polyvalent carboxylic acids; polyvalent amines and polyvalent carboxylic acids; phenolic compounds and carbonate esters; phenolic compounds and carbonic acids.
  • Examples include chloride.
  • the first substance and the second substance may be any substance in a combination thereof (for example, the first substance is a polyol and the second substance is a polyisocyanate. Often, the first substance may be a polyisocyanate and the second substance may be a polyol).
  • the first substance and the second substance may be water-soluble and may not be water-soluble (may be poorly water-soluble). “Water-soluble” means, for example, that the solubility in 100 g of ion-exchanged water at 25 ° C. is 1 g or more.
  • the polyol may be a compound having two or more hydroxyl groups, and diols, triols and the like can be used.
  • examples of the polyol include polyether polyols, polyester polyols, polycarbonate polyols, polysiloxane polyols, polyisoprene polyols, polyolefin polyols and the like.
  • the polyisocyanate may be a compound having two or more isocyanate groups, and diisocyanate, triisocyanate and the like can be used.
  • the polyisocyanate include aromatic isocyanates such as diphenylmethane diisocyanate, dimethyldiphenylmethane diisocyanate, tolylene diisocyanate (for example, tolylen-2,4-diisocyanate), xylylene diisocyanate, and p-phenylenediisocyanate; dicyclohexylmethane diisocyanate, isophorone diisocyanate, and the like.
  • Alicyclic isocyanate examples thereof include aliphatic isocyanates such as hexamethylene diisocyanate.
  • aldehyde examples include aliphatic aldehydes such as formaldehyde, acetaldehyde and propionaldehyde; and aromatic aldehydes such as benzaldehyde.
  • phenol compound examples include phenol, cresol, catechol, naphthol, hydroquinone and the like.
  • the first substance contains a polyol and the second substance is a polyisocyanate from the viewpoint that the surface area of the coated resin particles is particularly easy to adjust (easily increase).
  • a mode including the above is preferable.
  • the amount of the first substance may be in the following range with respect to 100 parts by mass of the water-absorbent resin particles from the viewpoint of facilitating the uniform penetration of the first substance into the water-absorbent resin particles.
  • the amount of the first substance is 0.01 part by mass or more, 0.05 part by mass or more, 0.8 part by mass or more, 0.1 part by mass or more, 0.5 part by mass or more, 0.8 part by mass or more, It may be 1 part by mass or more, 2 parts by mass or more, 3 parts by mass or more, 5 parts by mass or more, 8 parts by mass or more, or 10 parts by mass or more.
  • the amount of the first substance is 50 parts by mass or less, 40 parts by mass or less, 30 parts by mass or less, 20 parts by mass or less, 15 parts by mass or less, 10 parts by mass or less, 8 parts by mass or less, 5 parts by mass or less, 3 parts by mass. It may be 2 parts by mass or less, or 1 part by mass or less. From these viewpoints, the amount of the first substance may be 0.01 to 50 parts by mass.
  • the amount of the second substance is in the following range with respect to 100 parts by mass of the water-absorbent resin particles from the viewpoint that the second substance can be efficiently polymerized with the first substance on the surface of the water-absorbent resin particles. It's okay.
  • the amount of the second substance is 0.01 parts by mass or more, 0.05 parts by mass or more, 0.8 parts by mass or more, 0.1 parts by mass or more, 0.5 parts by mass or more, 1 part by mass or more, and 2 parts by mass. It may be 3 parts or more, 3 parts by mass or more, 4 parts by mass or more, or 4.5 parts by mass or more.
  • the amount of the second substance is 50 parts by mass or less, 40 parts by mass or less, 30 parts by mass or less, 20 parts by mass or less, 15 parts by mass or less, 10 parts by mass or less, 8 parts by mass or less, or 5 parts by mass or less. It may be there. From these viewpoints, the amount of the second substance may be 0.01 to 50 parts by mass.
  • the amount of the second substance is in the following range with respect to 100 parts by mass of the first substance from the viewpoint of easily polymerizing the second substance with the first substance on the surface of the water-absorbent resin particles. It's okay.
  • the amount of the second substance may be 1 part by mass or more, 3 parts by mass or more, 5 parts by mass or more, 10 parts by mass or more, 30 parts by mass or more, 40 parts by mass or more, or 45 parts by mass or more.
  • the amount of the second substance is 500 parts by mass or less, 400 parts by mass or less, 350 parts by mass or less, 300 parts by mass or less, 250 parts by mass or less, 200 parts by mass or less, 150 parts by mass or less, 120 parts by mass or less, 119 parts by mass. It may be 10 parts or less, 110 parts by mass or less, 100 parts by mass or less, 80 parts by mass or less, or 50 parts by mass or less. From these viewpoints, the amount of the second substance may be 1 to 500 parts by mass.
  • the method of supplying the first substance and the second substance is not particularly limited, and the method of supplying the substance in a state of being mixed with a solvent or a dispersion medium (solution state or dispersion state), or the substance itself is liquid (in a liquid state or a dispersion liquid state).
  • a method of supplying in a molten state) or a solid state can be mentioned.
  • a liquid in which the first substance or the second substance is mixed with a solvent or a dispersion medium can be obtained, for example, by dissolving the first substance or the second substance in a solvent or dispersing the second substance in a dispersion medium. Can be done.
  • the liquid in which the first substance or the second substance is mixed with the solvent or the dispersion medium may further contain water-absorbent resin particles.
  • the solvent water, a hydrophilic solvent (solvent compatible with water), a mixed solvent of water and a hydrophilic solvent and the like can be used.
  • the hydrophilic solvent include alcohols such as methanol, ethanol and isopropyl alcohol; glycols such as ethylene glycol; amides such as formamide and N, N-dimethylformamide; cellosolves such as methyl cellosolve and ethyl cellosolve; ketones such as acetone and methyl ethyl ketone; Esters such as ethyl acetate; ethers such as tetrahydrofuran can be mentioned.
  • the solvent of the first substance is preferably one that can expand the water-absorbent resin particles (it can be absorbed by the water-absorbent resin particles to be coated), and such a solvent includes water, alcohol, and the like.
  • the dispersion medium may include a hydrocarbon-based dispersion medium.
  • hydrocarbon-based dispersion medium chain aliphatic hydrocarbons such as n-hexane, n-heptane, 2-methylhexane, 3-methylhexane, 2,3-dimethylpentane, 3-ethylpentane, and n-octane; Aliphatic hydrocarbons such as cyclohexane, methylcyclohexane, cyclopentane, methylcyclopentane, trans-1,2-dimethylcyclopentane, cis-1,3-dimethylcyclopentane, trans-1,3-dimethylcyclopentane; benzene , Aromatic hydrocarbons such as toluene and xylene.
  • the coating step for example, by mixing a liquid containing the first substance and the water-absorbent resin particles and a liquid containing the second substance, a coating portion covering at least a part of the water-absorbent resin particles is formed. You may get it.
  • the content of the second substance in the liquid containing the second substance is based on the entire liquid from the viewpoint of easily polymerizing the second substance with the first substance on the surface of the water-absorbent resin particles. It may be in the following range.
  • the content of the second substance is 0.1% by mass or more, 0.5% by mass or more, 1% by mass or more, 3% by mass or more, 5% by mass or more, 8% by mass or more, or 10% by mass or more. It may be there.
  • the content of the second substance may be 50% by mass or less, 40% by mass or less, 30% by mass or less, 20% by mass or less, 15% by mass or less, or 10% by mass or less. From these viewpoints, the content of the second substance may be 0.1 to 50% by mass.
  • a mixed liquid (first substance and a liquid containing water) is mixed with a dispersion of water-absorbent resin particles before the coating step.
  • a mixing step of obtaining a liquid containing water-absorbent resin particles) may be provided.
  • the water-absorbent resin particles can be brought into contact with the first substance.
  • the method for producing coated resin particles according to the present embodiment may include a dispersion step for obtaining a dispersion of water-absorbent resin particles before the mixing step.
  • the dispersion of the water-absorbent resin particles can be obtained by dispersing the water-absorbent resin particles in a dispersion medium or by dispersing the water-absorbent resin particles in a gas.
  • the dispersion medium the above-mentioned hydrocarbon-based dispersion medium can be used.
  • the solvent the above-mentioned water, a hydrophilic solvent (solvent compatible with water), a mixed solvent of water and a hydrophilic solvent and the like may be used as a dispersion medium for the water-absorbent resin particles.
  • the water-absorbent resin particles may be expanded before the dispersion step.
  • the gas may be atmospheric, but preferably contains 90% by mass or more of an inert gas such as nitrogen gas.
  • the "dispersion of water-absorbent resin particles” has a state in which the majority of the individual water-absorbent resin particles are kept in non-contact with other water-absorbent resin particles.
  • “Majority of water-absorbent resin particles” is 30% by mass or more, 50% by mass or more, 70% by mass or more, 80% by mass or more, or 90% by mass based on the whole of the water-absorbent resin particles contained in the dispersion. It may be% or more.
  • the dispersion of the water-absorbent resin particles is preferably a dispersion obtained by dispersing the water-absorbent resin particles in a dispersion medium from the viewpoint of easily obtaining the dispersion.
  • the content of the water-absorbent resin particles in the dispersion liquid of the water-absorbent resin particles may be in the following range with respect to the entire dispersion from the viewpoint of facilitating efficient dispersion of the water-absorbent resin particles.
  • the content of the water-absorbent resin particles is 0.1% by mass or more, 0.5% by mass or more, 1% by mass or more, 3% by mass or more, 5% by mass or more, 6% by mass or more, or 7% by mass or more. It may be there.
  • the content of the water-absorbent resin particles is 50% by mass or less, 40% by mass or less, 30% by mass or less, 20% by mass or less, 15% by mass or less, 10% by mass or less, 9% by mass or less, or 8% by mass or less. May be. From these viewpoints, the content of the water-absorbent resin particles may be 0.1 to 50% by mass.
  • a first substance and a liquid containing water are added by adding the first substance to a solvent containing at least water before the mixing step.
  • a step of obtaining an aqueous solution of the above) may be provided.
  • the first substance and the liquid containing water can be obtained by adding the first substance to at least a solvent containing water.
  • the proportion of water in the solvent may be 50% by mass or more, 70% by mass or more, or 90% by mass or more.
  • the solvent may be in the form of water (substantially 100% by mass of the solvent is water), and the first substance and the liquid containing water dissolve the first substance in the solvent consisting of water. It may be an aqueous solution of the first substance obtained thereby.
  • the solvent contains water
  • the water-absorbent resin particles easily permeate into the water-absorbent resin particles when the water-absorbent resin particles come into contact with the first substance and the liquid containing water.
  • the first substance is likely to be retained on the surface of the water-absorbent resin particles.
  • the first substance easily polymerizes with the second substance on the surface of the water-absorbent resin particles, and the coating portion can be efficiently formed.
  • the content of the first substance in the liquid containing the first substance and water may be in the following range with respect to the entire liquid from the viewpoint of facilitating the uniform penetration of the first substance into the water-absorbent resin particles. ..
  • the content of the first substance is 0.1% by mass or more, 0.5% by mass or more, 1% by mass or more, 2% by mass or more, 3% by mass or more, 4% by mass or more, 5% by mass or more, 8% by mass. % Or more, or 10% by mass or more.
  • the content of the first substance is 50% by mass or less, 40% by mass or less, 30% by mass or less, 20% by mass or less, 15% by mass or less, 10% by mass or less, 8% by mass or less, or 5% by mass or less. May be. From these viewpoints, the content of the first substance may be 0.1 to 50% by mass.
  • the content of the first substance in the liquid containing the first substance and water is in the following range with respect to 100 parts by mass of water from the viewpoint of facilitating the uniform penetration of the first substance into the water-absorbent resin particles. Good.
  • the content of the first substance is 0.1 parts by mass or more, 0.5 parts by mass or more, 1 part by mass or more, 2 parts by mass or more, 3 parts by mass or more, 4 parts by mass or more, 5 parts by mass or more, and 6 parts by mass. It may be 10 parts by mass or more, 8 parts by mass or more, or 11 parts by mass or more.
  • the amount of the first substance is 50 parts by mass or less, 40 parts by mass or less, 30 parts by mass or less, 20 parts by mass or less, 15 parts by mass or less, 11 parts by mass or less, 10 parts by mass or less, 8 parts by mass or less, or It may be 6 parts by mass or less. From these viewpoints, the amount of the first substance may be 0.1 to 50 parts by mass.
  • the method for producing coated resin particles according to the present embodiment may include a dehydration step (drying step) in which the particles obtained in the coating step are dehydrated.
  • a dehydration step drying step
  • the dehydration treatment may be performed by performing a heat treatment.
  • the heating temperature may be, for example, 100 to 150 ° C.
  • the method for adjusting the particle surface area according to the present embodiment is the method for adjusting the particle surface area of the coated resin particles according to the present embodiment.
  • the first substance and the second substance that polymerizes with the first substance are polymerized on the surface of the water-absorbent resin particles in a water-absorbing state to absorb water.
  • the surface areas of the water-absorbent resin particles and the coated resin particles having the coated portion are adjusted based on the degree of expansion of the water-absorbent resin particles in the water-absorbing state in the coating step of obtaining the coated portion that covers at least a part of the resin particles.
  • the method for adjusting the particle surface surface according to the present embodiment when coating at least a part of the water-absorbent resin particles (coated body) with the coating portion which is a polymerization reaction product of the first substance and the second substance.
  • the surface area of the coated resin particles can be easily adjusted by adjusting the degree of expansion of the water-absorbent resin particles in the water-absorbing state.
  • the surface area of the coated resin particles having a particle diameter of, for example, 300 to 400 ⁇ m can be easily adjusted.
  • the degree of expansion of the water-absorbent resin particles in the water-absorbing state in the coating step can be adjusted to the degree of expansion (for example, 1.5 times or more) described above with respect to the method for producing the coated resin particles according to the present embodiment.
  • Example A1 Round-bottomed cylindrical separable flask with an inner diameter of 11 cm and an internal volume of 2 L equipped with a reflux condenser, a dropping funnel, a nitrogen gas introduction pipe, and a stirrer (a stirrer blade having two stages of four inclined paddle blades with a blade diameter of 5 cm).
  • a mixture was obtained by adding 293 g of n-heptane and 0.736 g of a maleic anhydride-modified ethylene-propylene copolymer (dispersant, manufactured by Mitsui Chemicals, Inc., High Wax 1105A) to this flask.
  • the dispersant was dissolved in n-heptane by heating the mixture to 80 ° C. with stirring, and then the mixture was cooled to 50 ° C.
  • hydroxyethyl cellulose manufactured by Sumitomo Seika Co., Ltd., HEC AW-15F
  • HEC AW-15F hydroxyethyl cellulose
  • 0.0736 g 0.0736 g (0.272 mmol) of potassium persulfate as a water-soluble radical polymerization initiator
  • ethylene as an internal cross-linking agent.
  • An aqueous solution of the first stage was prepared by adding 0.010 g (0.057 mmol) of glycol diglycidyl ether and then dissolving the mixture.
  • the first-stage polymer slurry liquid in the above-mentioned separable flask is cooled to 25 ° C., and the total amount of the above-mentioned second-stage aqueous solution is added to the above-mentioned first stage. It was added to the polymerized slurry solution of the eye. Subsequently, after replacing the inside of the flask with nitrogen for 30 minutes, the flask was again immersed in a water bath at 70 ° C. to raise the temperature of the reaction solution, and the second-stage polymerization reaction was carried out for 60 minutes to obtain a hydrogel-like weight. I got a coalescence.
  • the flask was immersed in an oil bath set at 125 ° C., and 257.7 g of water was extracted from the system by azeotropic distillation of n-heptane and water. Then, after pulling up the flask, the internal temperature was adjusted to 83 ° C. with the lower part slightly in contact with the oil bath. Then, 4.42 g (0.507 mmol) of a 2 mass% ethylene glycol diglycidyl ether aqueous solution was added to the flask as a surface cross-linking agent, and then the internal temperature was maintained at 83 ° C. for 2 hours.
  • the flask was immersed again in an oil bath set at 125 ° C. to raise the temperature, and 245 g of water was extracted from the system while refluxing n-heptane by azeotropic distillation of n-heptane and water. Then, n-heptane was evaporated at 125 ° C. and dried to obtain a dried product (polymer). By passing this dried product through a sieve having an opening of 850 ⁇ m, 236.8 g of water-absorbent resin particles A (coated body) in the form of aggregated spherical particles were obtained. The content of the liquid component of the water-absorbent resin particles A before contacting with the first substance below was 10% by mass. The method of calculating the content of the liquid component will be described later.
  • monomer type A which is the first substance
  • a mixed solution aqueous polyol solution
  • a polyether polyol DK polyol 3817 manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.
  • 76.0 g of ion-exchanged water was added.
  • monomer type B 19.0 g of a mixed solution (isocyanate solution) of 1.9 g of trilen-2,4-diisocyanate and 17.1 g of acetone was prepared.
  • a round-bottomed cylindrical type having an inner diameter of 11 cm and an internal volume of 2 L equipped with a reflux condenser, a dropping funnel, a nitrogen gas introduction pipe, and a stirrer (a stirrer blade having two stages of four inclined paddle blades with a blade diameter of 5 cm).
  • a separable flask was prepared. To this flask, 40.0 g of the above-mentioned water-absorbent resin particles A (water-absorbent resin particles obtained by the reverse phase suspension polymerization method, coated body) was added. Then, 480 g of n-heptane was added as a hydrocarbon dispersion medium, and then the mixture was stirred at 1000 rpm to obtain a dispersion liquid as a dispersion.
  • Example A2 Similar to Experimental Example A1 except that the solution of monomer type A, which is the first substance, was changed to 40 g of a mixed solution of 4 g of a polyether polyol (DK polyol 3817 manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) and 36 g of ion-exchanged water. By doing so, coated resin particles A2 were produced. The degree of expansion of the water-absorbent resin particles A in the water-absorbing state after the monomer type A, which is the first substance, was brought into contact with the water-absorbent resin particles A was 2.1 times.
  • a polyether polyol DK polyol 3817 manufactured by Daiichi Kogyo Seiyaku Co., Ltd.
  • Example B1 509.71 g (7.07 mol) of 100% acrylic in a round-bottomed cylindrical separable flask with an inner diameter of 11 cm and an internal volume of 2 L equipped with a stirrer (a stirrer with two stages of four inclined paddle blades with a blade diameter of 5 cm). I added acid. While stirring this acrylic acid, 436.47 g of ion-exchanged water was added into the separable flask. Then, 444.68 g of 48% by mass sodium hydroxide was added dropwise under an ice bath (1 ° C.) to partially neutralize the acrylic acid having a monomer concentration of 45.08% by mass (neutralization rate: 75.44 mol). %) 139.86 g was prepared. This operation was repeated 3 times and used for the polymerization described later.
  • reaction solution (monomer aqueous solution). It was. Next, this reaction solution was replaced with nitrogen gas for 30 minutes in a nitrogen gas atmosphere. Next, after supplying the above-mentioned reaction solution to a stainless steel dual-arm kneader equipped with a thermometer, a nitrogen blow tube, an openable / closable lid, two sigma type blades and a jacket, the reaction solution is kept at 30 ° C. Was replaced with nitrogen gas.
  • This subdivided particulate hydrogel was spread on a wire mesh with a mesh size of 0.8 cm ⁇ 0.8 cm, and then dried with hot air at 160 ° C. for 60 minutes to obtain a dried product.
  • the dried product was crushed using a centrifugal crusher (manufactured by Retsch, ZM200, screen diameter 1 mm, 12000 rpm) to obtain amorphous crushed water-absorbent resin particles. Further, by classifying the water-absorbent resin particles with a wire mesh having a mesh size of 850 ⁇ m, a wire mesh having a mesh size of 250 ⁇ m, and a wire mesh having a mesh size of 180 ⁇ m, the water-absorbent resin particles pass through the wire mesh having a mesh size of 850 ⁇ m and pass through the wire mesh having a mesh size of 250 ⁇ m. Water-absorbent resin particles B, which was a fraction that was not present, were obtained. The content of the liquid component of the water-absorbent resin particles B before contacting with the first substance, the monomer type A, was 5% by mass. The method of calculating the content of the liquid component will be described later.
  • the water-absorbent resin particles B are coated with polyurethane in the same manner as in Experimental Example A1 except that the water-absorbent resin particles B (water-absorbent resin particles obtained by the aqueous solution polymerization method) are used as the object to be coated.
  • the coated resin particles B1 were prepared in 1.
  • the degree of expansion of the water-absorbent resin particles B in the water-absorbing state after the monomer type A, which is the first substance, and the water-absorbent resin particles B were brought into contact with each other was 3.1 times.
  • the content of the liquid component was measured by the following procedure. 2.000 g of water-absorbent resin particles (particles not used as the object to be coated) were heated for 2 hours with a hot air dryer (FV-320, manufactured by ADVANTEC) set at 105 ° C. The reduced mass [g] of the water-absorbent resin particles was determined to be the content [g] of the liquid component contained in the water-absorbent resin particles, and the content rate of the liquid component was obtained by the following formula (1).
  • Formula (1): Content of liquid component of water-absorbent resin particles before contact with the first substance [mass%] ⁇ reduced mass of water-absorbent resin particles [g] / mass of water-absorbent resin particles (2. 000g) ⁇ x 100
  • the degree of expansion of the water-absorbent resin particles in the water-absorbing state was calculated by the following procedure. First, after preparing the water-absorbent resin particles before contacting with the first substance, the initial content of the liquid component in the water-absorbent resin particles was calculated by the following formula (2). Next, the pure content of the water-absorbent resin particles (mass of the water-absorbent resin particles excluding the liquid component) was calculated by the following formula (3). Then, the degree of expansion of the water-absorbent resin particles in the water-absorbing state was calculated by the following formula (4).
  • the above-mentioned coated resin particles A1, A2 and B1 and the above-mentioned water-absorbent resin particles A and B were prepared as evaluation particles.
  • the state of the evaluation particles was observed using a scanning electron microscope (SEM, manufactured by JEOL Ltd., JSM-6390LA). After sticking one side of the double-sided carbon tape on the sample stage, the evaluation particles were placed on the other side of one side of the double-sided carbon tape.
  • the acceleration voltage was set to 15 kV and the operating distance was 10 mm, and the evaluation particles were observed at a magnification of 500 times.
  • 2 and 3 are drawings showing SEM photographs of the coated resin particles and the water-absorbent resin particles.
  • FIG. 2A is a drawing showing an SEM photograph of the coated resin particles A1
  • FIG. 2B is a drawing showing an SEM photograph of the coated resin particles A2
  • FIG. 2C is a water-absorbent resin. It is a drawing which shows the SEM photograph of particle A.
  • FIG. 3A is a drawing showing an SEM photograph of the coated resin particles B1
  • FIG. 3B is a drawing showing an SEM photograph of the water-absorbent resin particles B.
  • FIG. 2 it is presumed that the specific surface area of the coated resin particles A1 and A2 having fold-like protrusions on the surface is larger than the specific surface area of the water-absorbent resin particles A, and the specific surface area is determined in the measurement of the specific surface area described later. confirmed. From this result, it is inferred from FIG. 3 that the specific surface area of the coated resin particles B1 having fold-like protrusions on the surface is larger than the specific surface area of the water-absorbent resin particles B.
  • the specific surface area was measured from the multipoint BET plot by measuring the adsorption isotherm at a temperature of 77 K by a method using krypton gas as the adsorption gas with a specific surface area measuring device (AUTOSORB-1, manufactured by Kantachrome). Asked.
  • the specific surface area of the water-absorbent resin particles A was 0.036 m 2 / g.
  • the specific surface area of the coated resin particles obtained by coating the water-absorbent resin particles A with the coating portion the specific surface area of the coated resin particles A1 is 0.060 m 2 / g, and the specific surface area of the coated resin particles A2 is 0. It was 046 m 2 / g.

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Abstract

第１の物質と、当該第１の物質と重合反応する第２の物質とを吸水状態の吸水性樹脂粒子の表面で重合反応させて、前記吸水性樹脂粒子の少なくとも一部を被覆する被覆部を得る被覆工程を備える、被覆樹脂粒子の製造方法。第１の物質と、当該第１の物質と重合反応する第２の物質とを吸水状態の吸水性樹脂粒子の表面で重合反応させて、前記吸水性樹脂粒子の少なくとも一部を被覆する被覆部を得る被覆工程における前記吸水状態の吸水性樹脂粒子の膨張度に基づき、前記吸水性樹脂粒子及び前記被覆部を有する被覆樹脂粒子の表面積を調整する、粒子表面積の調整方法。

Description

被覆樹脂粒子の製造方法及び粒子表面積の調整方法
　本発明は、被覆樹脂粒子の製造方法及び粒子表面積の調整方法に関する。
　吸水性樹脂粒子は、紙おむつ、生理用品、簡易トイレ等の衛生材料；保水剤、土壌改良剤等の農園芸材料；止水剤、結露防止剤等の工業資材などの種々の分野で広く使用されている。吸水性樹脂粒子には、吸水速度等の各種性能の制御が求められている（例えば、下記特許文献１参照）。
特開２０１６－２８１１７号公報
　本発明者らは、吸水速度等の各種性能を制御する方法として粒子表面積を調整することに着目した上で、吸水性樹脂粒子の作製条件を調整する方法とは異なる方法により粒子表面積を調整可能であり、粒子表面積を増加させることができることを見出した。
　本発明の一側面は、粒子表面積を増加させることが可能な被覆樹脂粒子の製造方法を提供することを目的とする。本発明の他の一側面は、粒子表面積を容易に調整可能な粒子表面積の調整方法を提供することを目的とする。
　本発明の一側面は、第１の物質と、当該第１の物質と重合反応する第２の物質とを吸水状態の吸水性樹脂粒子の表面で重合反応させて、前記吸水性樹脂粒子の少なくとも一部を被覆する被覆部を得る被覆工程を備える、被覆樹脂粒子の製造方法を提供する。
　本発明の他の一側面は、第１の物質と、当該第１の物質と重合反応する第２の物質とを吸水状態の吸水性樹脂粒子の表面で重合反応させて、前記吸水性樹脂粒子の少なくとも一部を被覆する被覆部を得る被覆工程における前記吸水状態の吸水性樹脂粒子の膨張度に基づき、前記吸水性樹脂粒子及び前記被覆部を有する被覆樹脂粒子の表面積を調整する、粒子表面積の調整方法を提供する。
　本発明の一側面によれば、粒子表面積を増加させることが可能な被覆樹脂粒子の製造方法を提供することができる。本発明の他の一側面によれば、粒子表面積を容易に調整可能な粒子表面積の調整方法を提供することができる。
被覆樹脂粒子の一例を示す模式断面図である。 被覆樹脂粒子及び吸水性樹脂粒子のＳＥＭ写真を示す図面である。 被覆樹脂粒子及び吸水性樹脂粒子のＳＥＭ写真を示す図面である。
　以下、本発明の実施形態について詳細に説明する。但し、本発明は、以下の実施形態に限定されるものではなく、その要旨の範囲内で種々変形して実施することができる。
　本明細書において、「アクリル」及び「メタクリル」を合わせて「（メタ）アクリル」と表記する。「アクリレート」及び「メタクリレート」も同様に「（メタ）アクリレート」と表記する。「（ポリ）」とは、「ポリ」の接頭語がある場合及びない場合の双方を意味するものとする。本明細書に段階的に記載されている数値範囲において、ある段階の数値範囲の上限値又は下限値は、他の段階の数値範囲の上限値又は下限値と任意に組み合わせることができる。本明細書に記載されている数値範囲において、その数値範囲の上限値又は下限値は、実験例に示されている値に置き換えてもよい。室温とは、２５℃を意味するものとする。本明細書に例示する材料は、１種を単独で用いてもよく、２種以上を組み合わせて用いてもよい。組成物中の各成分の含有量は、組成物中に各成分に該当する物質が複数存在する場合、特に断らない限り、組成物中に存在する当該複数の物質の合計量を意味する。
　本実施形態に係る被覆樹脂粒子の製造方法は、第１の物質と、当該第１の物質と重合反応する第２の物質とを吸水状態の吸水性樹脂粒子（被コーティング体）の表面で重合反応させて、吸水性樹脂粒子の少なくとも一部を被覆する被覆部を得る被覆工程を備える。
　本実施形態に係る被覆樹脂粒子の製造方法によれば、第１の物質と第２の物質との重合反応物である被覆部によって吸水性樹脂粒子（被コーティング体）の少なくとも一部を被覆することにより被覆樹脂粒子の表面積を増加させることができる。例えば、本実施形態に係る被覆樹脂粒子の製造方法によれば、被覆工程における吸水状態の吸水性樹脂粒子の膨張度を調整することにより被覆樹脂粒子の表面積を増加させることができる。本実施形態に係る被覆樹脂粒子の製造方法によれば、例えば粒子径３００～４００μｍの被覆樹脂粒子の表面積を増加させることができる。
　本発明者は、下記の知見を見出した。被覆部を有しない吸水状態の吸水性樹脂粒子が脱水されると、粒子表面積が固定化されていないことから、粒子が収縮するに伴い粒子表面積が粒子の状態に応じて大きく変化するため、収縮前の吸水性樹脂粒子の状態に基づき粒子表面積を調整しづらい。一方、被覆部を有する吸水状態の吸水性樹脂粒子が脱水されると、被覆部によって粒子の表面が固定化されていることにより、粒子が収縮する際に粒子表面積が収縮前後で大きく変化しづらいことから、収縮前の吸水性樹脂粒子の状態として吸水性樹脂粒子の膨張度に応じて表面積が調整されやすい。そのため、被覆部を有する被覆樹脂粒子の製造過程における吸水性樹脂粒子の膨張度を調整することにより被覆樹脂粒子の表面積を容易に調整可能であり、被覆樹脂粒子の表面積を増加させることができる。
　本実施形態に係る被覆樹脂粒子の製造方法によれば、被覆樹脂粒子を得ることができる。当該被覆樹脂粒子は、吸水性樹脂粒子と、当該吸水性樹脂粒子の少なくとも一部を被覆する被覆部と、を有する。
　被覆対象の吸水性樹脂粒子の形状は、特に限定されず、例えば、略球状、不定形状、顆粒状等であってよく、これらの形状を有する一次粒子が凝集した形状であってもよい。不定形状の吸水性樹脂粒子は、例えば、樹脂塊体を破砕機で破砕することで得られる。
　吸水性樹脂粒子は、吸水性を有する樹脂から構成されていれば特に限定されない。吸水性樹脂粒子における２５℃のイオン交換水の吸水量（常圧下の吸水量）は、例えば１０ｇ／ｇ以上であってよい。
　吸水性樹脂粒子は、例えば、エチレン性不飽和単量体を含む単量体を重合させて得られる架橋重合体を含むことができる。すなわち、吸水性樹脂粒子は、エチレン性不飽和単量体に由来する構造単位を有することが可能であり、エチレン性不飽和単量体に由来する構造単位を有する架橋重合体を含むことができる。エチレン性不飽和単量体の重合方法としては、逆相懸濁重合法、水溶液重合法、バルク重合法、沈殿重合法等が挙げられる。
　エチレン性不飽和単量体は、水溶性エチレン性不飽和単量体（例えば、２５℃のイオン交換水１００ｇに対する溶解度が１ｇ以上のエチレン性不飽和単量体）であってよい。エチレン性不飽和単量体としては、（メタ）アクリル酸及びその塩、２－（メタ）アクリルアミド－２－メチルプロパンスルホン酸及びその塩、（メタ）アクリルアミド、Ｎ，Ｎ－ジメチル（メタ）アクリルアミド、２－ヒドロキシエチル（メタ）アクリレート、Ｎ－メチロール（メタ）アクリルアミド、ポリエチレングリコールモノ（メタ）アクリレート、Ｎ，Ｎ－ジエチルアミノエチル（メタ）アクリレート、Ｎ，Ｎ－ジエチルアミノプロピル（メタ）アクリレート、ジエチルアミノプロピル（メタ）アクリルアミド等が挙げられる。エチレン性不飽和単量体がアミノ基を有する場合、当該アミノ基は４級化されていてもよい。エチレン性不飽和単量体は、被覆樹脂粒子の表面積を特に調整しやすい（増加させやすい）観点から、（メタ）アクリル酸及びその塩からなる群より選ばれる少なくとも一種を含んでよい。吸水性樹脂粒子は、被覆樹脂粒子の表面積を特に調整しやすい（増加させやすい）観点から、（メタ）アクリル酸及びその塩からなる群より選ばれる少なくとも一種に由来する構造単位を有することが好ましい。
　エチレン性不飽和単量体が酸性基を有する場合、酸性基を中和してから重合反応に用いてもよい。エチレン性不飽和単量体における中和度は、エチレン性不飽和単量体中の酸性基の１０～１００モル％、５０～９０モル％、又は、６０～８０モル％であってよい。
　吸水性樹脂粒子を得るための単量体としては、上述のエチレン性不飽和単量体以外の単量体が使用されてもよい。このような単量体は、例えば、上述のエチレン性不飽和単量体を含む水溶液に混合して用いることができる。エチレン性不飽和単量体の使用量は、単量体全量（吸水性樹脂粒子を得るための単量体全量。例えば、架橋重合体の構造単位を与える単量体の全量。以下同様）に対して７０～１００モル％であることが好ましい。中でも、（メタ）アクリル酸及びその塩の割合が単量体全量に対して７０～１００モル％であることがより好ましい。「（メタ）アクリル酸及びその塩の割合」は、（メタ）アクリル酸及びその塩の合計量の割合を意味する。
　本実施形態によれば、吸水性樹脂粒子の一例として、エチレン性不飽和単量体に由来する構造単位を有する架橋重合体を含む吸水性樹脂粒子であって、前記エチレン性不飽和単量体が、（メタ）アクリル酸及びその塩からなる群より選ばれる少なくとも一種を含み、前記（メタ）アクリル酸及びその塩の割合が、前記吸水性樹脂粒子を得るための単量体全量（例えば、前記架橋重合体の構造単位を与える単量体の全量）に対して７０～１００モル％である、吸水性樹脂粒子を提供することができる。
　重合の際に自己架橋による架橋が生じ得るが、内部架橋剤を用いることで架橋を促してもよい。内部架橋剤を用いると、吸水性樹脂粒子の吸水特性を制御しやすい。内部架橋剤としては、（ポリ）エチレングリコールジグリシジルエーテル、（ポリ）プロピレングリコールジグリシジルエーテル、（ポリ）グリセリンジグリシジルエーテル、（ポリ）グリセリントリグリシジルエーテル、（ポリ）プロピレングリコールポリグリシジルエーテル、ポリグリセロールポリグリシジルエーテル等のポリグリシジル化合物；ジビニル系化合物；ジアルコール系化合物；ジアクリレート系化合物などが挙げられる。
　吸水性樹脂粒子は、架橋重合体粒子のみから構成されていてもよいが、例えば、ゲル安定剤、金属キレート剤、流動性向上剤（滑剤）等を更に含んでいてもよい。これらの成分は、架橋重合体粒子の内部、架橋重合体粒子の表面上、又は、それらの両方に配置され得る。
　被覆部は、上述の第１の物質と第２の物質との重合反応物である。被覆部は、水溶性であってよく、水溶性でなくてもよい（難水溶性であってもよい）。被覆部が水溶性である場合、被覆部の溶解度は、例えば、２５℃のイオン交換水１００ｇに対して１ｇ以上（例えば１～１５０ｇ）であってよい。被覆部の構成材料は、ウレタン樹脂、フェノール樹脂（例えば、フェノール化合物とアルデヒドとの縮合物）、ポリエステル、ポリアミド、ポリカーボネート等の逐次重合反応物；ポリビニルアルコール、ポリアクリルアミド、ポリアルキレンオキシド、ポリアルキレングリコール等の連鎖重合反応物などを含み得る。なお、第１の物質と第２の物質は異なっていてもよく、同じであってもよい。
　本実施形態に係る被覆樹脂粒子の中位粒子径は、下記の範囲であってよい。被覆樹脂粒子の中位粒子径は、１００μｍ以上、１５０μｍ以上、２００μｍ以上、２５０μｍ以上、３００μｍ以上、３５０μｍ以上、３５５μｍ以上、３６０μｍ以上、３８０μｍ以上、４００μｍ以上、又は、４１０μｍ以上であってよい。被覆樹脂粒子の中位粒子径は、８００μｍ以下、７００μｍ以下、６００μｍ以下、５００μｍ以下、４５０μｍ以下、４１０μｍ以下、４００μｍ以下、３８０μｍ以下、３６０μｍ以下、又は、３５５μｍ以下であってよい。これらの観点から、被覆樹脂粒子の中位粒子径は、１００～８００μｍ、１５０～７００μｍ、２００～６００μｍ、又は、２５０～５００μｍであってよい。
　図１は、被覆樹脂粒子の一例を示す模式断面図である。図１に示す被覆樹脂粒子１は、樹脂粒子１ａと、樹脂粒子（吸水性樹脂粒子）１ａの表面の少なくとも一部を被覆するコーティング層（被覆部）１ｂとを有する。図１では、樹脂粒子１ａの表面全体がコーティング層１ｂによって被覆されている。この場合、例えば、コーティング層１ｂが水溶性であることにより、コーティング層１ｂが溶解して消失することにより、樹脂粒子１ａを水に接触させる挙動（例えば経時変化）を調整できる。樹脂粒子１ａの表面においてコーティング層１ｂの被覆量を調整することにより、水に対する樹脂粒子１ａの接触量を調整できる。
　本実施形態に係る被覆樹脂粒子の製造方法における被覆工程では、第１の物質と、当該第１の物質と重合反応する第２の物質とを吸水状態の吸水性樹脂粒子の表面で重合反応させる。被覆工程では、吸水性樹脂粒子の表面において第１の物質と第２の物質とを接触させることができる。
　被覆工程における重合反応は、逐次重合反応又は連鎖重合反応であることが好ましく、粒子の凝集が発生し難いことが推定される観点から、逐次重合反応であることがより好ましい。逐次重合反応の場合、重合反応に重合開始剤が不要であるため、重合開始剤が粒子表面に表出し難く、被覆樹脂粒子の表面積を特に調整しやすい（増加させやすい）と本発明者らは推測している。第１の物質と第２の物質との逐次重合反応の反応温度は、例えば１５～２００℃であってよい。
　被覆工程における吸水状態の吸水性樹脂粒子の膨張度（質量基準の膨張度。吸水状態における吸水性樹脂粒子の質量／吸水性樹脂粒子の純分（乾燥状態の吸水性樹脂粒子の質量））は、下記の範囲であってよい。膨張度は、１．５倍以上、１．７５倍以上、２．０倍以上、２．１倍以上、２．５倍以上、２．７５倍以上、３．０倍以上、又は、３．２倍以上であってよい。膨張度は、５倍以下、４．５倍以下、４．０倍以下、又は、３．５倍以下であってよい。膨張度としては、２５℃における膨張度を用いることができる。吸水状態の吸水性樹脂粒子の膨張度としては、第１の物質と第２の物質とが接触（重合反応）する時点における膨張度を用いることが可能であり、例えば、吸水性樹脂粒子と第１の物質とを接触させた後に第２の物質を供給する場合、第２の物質を供給する時点における膨張度を用いることができる。膨張度は、被覆対象である吸水性樹脂粒子に含まれる含水量、第１の物質を溶質とする溶液に含まれる溶媒量等を調整することで所望の値に調整することができる。
　第１の物質及び第２の物質の組み合わせとしては、ポリオール及びポリイソシアネート；アルデヒド及びフェノール化合物；ポリオール及び多価カルボン酸；多価アミン及び多価カルボン酸；フェノール化合物及び炭酸エステル；フェノール化合物及び炭酸クロリド等が挙げられる。第１の物質及び第２の物質は、これらの組み合わせにおけるいずれの物質であってもよい（例えば、第１の物質がポリオールであり、かつ、第２の物質がポリイソシアネートである態様であってよく、第１の物質がポリイソシアネートであり、かつ、第２の物質がポリオールである態様であってよい）。第１の物質及び第２の物質は、水溶性であってよく、水溶性でなくてもよい（難水溶性であってもよい）。「水溶性」とは、例えば、２５℃のイオン交換水１００ｇに対する溶解度が１ｇ以上であることを意味する。
　ポリオールは、２以上の水酸基を有する化合物であればよく、ジオール、トリオール等を用いることができる。ポリオールとしては、ポリエーテルポリオール、ポリエステルポリオール、ポリカーボネートポリオール、ポリシロキサンポリオール、ポリイソプレンポリオール、ポリオレフィンポリオール等が挙げられる。
　ポリイソシアネートは、２以上のイソシアネート基を有する化合物であればよく、ジイソシアネート、トリイソシアネート等を用いることができる。ポリイソシアネートとしては、ジフェニルメタンジイソシアネート、ジメチルジフェニルメタンジイソシアネート、トリレンジイソシアネート（例えばトリレン－２，４－ジイソシアナート）、キシリレンジイソシアネート、ｐ－フェニレンジイソシアネート等の芳香族イソシアネート；ジシクロヘキシルメタンジイソシアネート、イソフォロンジイソシアネート等の脂環式イソシアネート；ヘキサメチレンジイソシアネート等の脂肪族イソシアネートなどが挙げられる。
　アルデヒドとしては、ホルムアルデヒド、アセトアルデヒド、プロピオンアルデヒド等の脂肪族アルデヒド；ベンズアルデヒド等の芳香族アルデヒドなどが挙げられる。
　フェノール化合物としては、フェノール、クレゾール、カテコール、ナフトール、ヒドロキノン等が挙げられる。
　第１の物質及び第２の物質の組み合わせとしては、被覆樹脂粒子の表面積を特に調整しやすい（増加させやすい）観点から、第１の物質がポリオールを含み、かつ、第２の物質がポリイソシアネートを含む態様が好ましい。
　第１の物質の量は、第１の物質を均一に吸水性樹脂粒子に浸透させやすい観点から、吸水性樹脂粒子１００質量部に対して下記の範囲であってよい。第１の物質の量は、０．０１質部以上、０．０５質量部以上、０．８質量部以上、０．１質量部以上、０．５質量部以上、０．８質量部以上、１質量部以上、２質量部以上、３質量部以上、５質量部以上、８質量部以上、又は、１０質量部以上であってよい。第１の物質の量は、５０質量部以下、４０質量部以下、３０質量部以下、２０質量部以下、１５質量部以下、１０質量部以下、８質量部以下、５質量部以下、３質量部以下、２質量部以下、又は、１質量部以下であってよい。これらの観点から、第１の物質の量は、０．０１～５０質量部であってよい。
　第２の物質の量は、吸水性樹脂粒子の表面において第２の物質を第１の物質と効率的に重合反応させやすい観点から、吸水性樹脂粒子１００質量部に対して下記の範囲であってよい。第２の物質の量は、０．０１質部以上、０．０５質量部以上、０．８質量部以上、０．１質量部以上、０．５質量部以上、１質量部以上、２質量部以上、３質量部以上、４質量部以上、又は、４．５質量部以上であってよい。第２の物質の量は、５０質量部以下、４０質量部以下、３０質量部以下、２０質量部以下、１５質量部以下、１０質量部以下、８質量部以下、又は、５質量部以下であってよい。これらの観点から、第２の物質の量は、０．０１～５０質量部であってよい。
　第２の物質の量は、吸水性樹脂粒子の表面において第２の物質を第１の物質と効率的に重合反応させやすい観点から、第１の物質１００質量部に対して下記の範囲であってよい。第２の物質の量は、１質量部以上、３質量部以上、５質量部以上、１０質量部以上、３０質量部以上、４０質量部以上、又は、４５質量部以上であってよい。第２の物質の量は、５００質量部以下、４００質量部以下、３５０質量部以下、３００質量部以下、２５０質量部以下、２００質量部以下、１５０質量部以下、１２０質量部以下、１１９質量部以下、１１０質量部以下、１００質量部以下、８０質量部以下、又は、５０質量部以下であってよい。これらの観点から、第２の物質の量は、１～５００質量部であってよい。
　第１の物質及び第２の物質の供給方法としては、特に限定されず、当該物質を溶媒又は分散媒と混合した状態（溶液状態又は分散液状態）で供給する方法、当該物質自体が液状（例えば溶融状態）又は固形状の状態で供給する方法などが挙げられる。第１の物質又は第２の物質を溶媒又は分散媒と混合した状態の液は、例えば、第１の物質又は第２の物質を、溶媒に溶解、又は、分散媒に分散させることにより得ることができる。第１の物質又は第２の物質を溶媒又は分散媒と混合した状態の液は、吸水性樹脂粒子を更に含有してよい。
　溶媒としては、水、親水性溶媒（水と相溶する溶媒）、水及び親水性溶媒の混合溶媒等を用いることができる。親水性溶媒としては、メタノール、エタノール、イソプロピルアルコール等のアルコール；エチレングリコール等のグリコール；ホルムアミド、Ｎ，Ｎ－ジメチルホルムアミド等のアミド；メチルセロソルブ、エチルセロソルブ等のセロソルブ；アセトン、メチルエチルケトン等のケトン；酢酸エチル等のエステル；テトラヒドロフラン等のエーテルなどが挙げられる。
　特に、第１の物質の溶媒は、吸水性樹脂粒子を膨張させ得る（被覆対象である吸水性樹脂粒子に吸収され得る）ものであることが好ましく、そのような溶媒としては、水、アルコール、及び、水とアルコールを含む混合溶媒からなる群より選ばれる少なくとも一種を含むことが好ましく、水を含むことがより好ましく、膨張度を調整しやすい観点から、実質的に水のみからなることが更に好ましい。
　分散媒は、炭化水素系分散媒を含んでよい。炭化水素系分散媒としては、ｎ－ヘキサン、ｎ－ヘプタン、２－メチルヘキサン、３－メチルヘキサン、２，３－ジメチルペンタン、３－エチルペンタン、ｎ－オクタン等の鎖状脂肪族炭化水素；シクロヘキサン、メチルシクロヘキサン、シクロペンタン、メチルシクロペンタン、ｔｒａｎｓ－１，２－ジメチルシクロペンタン、ｃｉｓ－１，３－ジメチルシクロペンタン、ｔｒａｎｓ－１，３－ジメチルシクロペンタン等の脂環式炭化水素；ベンゼン、トルエン、キシレン等の芳香族炭化水素などが挙げられる。
　被覆工程では、例えば、第１の物質及び吸水性樹脂粒子を含有する液と、第２の物質を含有する液とを混合することにより、吸水性樹脂粒子の少なくとも一部を被覆する被覆部を得てよい。
　第２の物質を含有する液における第２の物質の含有量は、吸水性樹脂粒子の表面において第２の物質を第１の物質と効率的に重合反応させやすい観点から、液の全体を基準として下記の範囲であってよい。第２の物質の含有量は、０．１質量％以上、０．５質量％以上、１質量％以上、３質量％以上、５質量％以上、８質量％以上、又は、１０質量％以上であってよい。第２の物質の含有量は、５０質量％以下、４０質量％以下、３０質量％以下、２０質量％以下、１５質量％以下、又は、１０質量％以下であってよい。これらの観点から、第２の物質の含有量は、０．１～５０質量％であってよい。
　本実施形態に係る被覆樹脂粒子の製造方法は、被覆工程の前に、吸水性樹脂粒子の分散体に、第１の物質及び水を含む液を混合することにより混合液（第１の物質及び吸水性樹脂粒子を含有する液）を得る混合工程を備えてよい。混合工程では、吸水性樹脂粒子と第１の物質とを接触させることができる。
　本実施形態に係る被覆樹脂粒子の製造方法は、混合工程の前に、吸水性樹脂粒子の分散体を得る分散工程を備えてよい。吸水性樹脂粒子の分散体は、吸水性樹脂粒子を分散媒に分散させること、又は、吸水性樹脂粒子を気体中に分散させることにより得ることができる。分散媒としては、上述した炭化水素系分散媒を用いることができる。溶媒として上述した水、親水性溶媒（水と相溶する溶媒）、水及び親水性溶媒の混合溶媒等を吸水性樹脂粒子の分散媒として用いてもよい。分散工程の前に、吸水性樹脂粒子を膨張させてもよい。吸水性樹脂粒子を気体中に分散させた分散体を得る場合、当該気体は、大気であってよいが、窒素ガス等の不活性ガスを９０質量％以上含むことが好ましい。
　「吸水性樹脂粒子の分散体」は、個々の吸水性樹脂粒子の大多数が他の吸水性樹脂粒子と非接触に保たれた状態を有している。「吸水性樹脂粒子の大多数」は、分散体に含まれる吸水性樹脂粒子の全体を基準として、３０質量％以上、５０質量％以上、７０質量％以上、８０質量％以上、又は、９０質量％以上であってよい。吸水性樹脂粒子の分散体は、当該分散体を容易に得られる観点から、吸水性樹脂粒子を分散媒に分散させて得られる分散液であることが好ましい。
　吸水性樹脂粒子の分散液における吸水性樹脂粒子の含有量は、吸水性樹脂粒子を効率的に分散させやすい観点から、分散体の全体を基準として下記の範囲であってよい。吸水性樹脂粒子の含有量は、０．１質量％以上、０．５質量％以上、１質量％以上、３質量％以上、５質量％以上、６質量％以上、又は、７質量％以上であってよい。吸水性樹脂粒子の含有量は、５０質量％以下、４０質量％以下、３０質量％以下、２０質量％以下、１５質量％以下、１０質量％以下、９質量％以下、又は、８質量％以下であってよい。これらの観点から、吸水性樹脂粒子の含有量は、０．１～５０質量％であってよい。
　本実施形態に係る被覆樹脂粒子の製造方法は、混合工程の前に、少なくとも水を含む溶媒に第１の物質を添加することにより、第１の物質及び水を含む液（例えば第１の物質の水溶液）を得る工程を備えてよい。
　第１の物質及び水を含む液は、少なくとも水を含む溶媒に第１の物質を添加することにより得ることができる。当該溶媒における水の割合は、５０質量％以上、７０質量％以上、又は、９０質量％以上であってよい。溶媒は、水からなる態様（溶媒の実質的に１００質量％が水である態様）であってよく、第１の物質及び水を含む液は、水からなる溶媒に第１の物質を溶解させることにより得られる第１の物質の水溶液であってよい。
　溶媒が水を含んでいるため、第１の物質及び水を含む液に吸水性樹脂粒子が接触することにより吸水性樹脂粒子に第１の物質が浸透しやすい。換言すれば、吸水性樹脂粒子の表面に第１の物質が保持されやすい。その結果、被覆工程において、吸水性樹脂粒子の表面において第１の物質が第２の物質と重合反応しやすく、被覆部を効率的に形成することができると推測される。
　第１の物質及び水を含む液における第１の物質の含有量は、第１の物質を均一に吸水性樹脂粒子に浸透させやすい観点から、液の全体を基準として下記の範囲であってよい。第１の物質の含有量は、０．１質量％以上、０．５質量％以上、１質量％以上、２質量％以上、３質量％以上、４質量％以上、５質量％以上、８質量％以上、又は、１０質量％以上であってよい。第１の物質の含有量は、５０質量％以下、４０質量％以下、３０質量％以下、２０質量％以下、１５質量％以下、１０質量％以下、８質量％以下、又は、５質量％以下であってよい。これらの観点から、第１の物質の含有量は、０．１～５０質量％であってよい。
　第１の物質及び水を含む液における第１の物質の含有量は、第１の物質を均一に吸水性樹脂粒子に浸透させやすい観点から、水１００質量部に対して下記の範囲であってよい。第１の物質の含有量は、０．１質量部以上、０．５質量部以上、１質量部以上、２質量部以上、３質量部以上、４質量部以上、５質量部以上、６質量部以上、８質量部以上、１０質量部以上、又は、１１質量部以上であってよい。第１の物質の量は、５０質量部以下、４０質量部以下、３０質量部以下、２０質量部以下、１５質量部以下、１１質量部以下、１０質量部以下、８質量部以下、又は、６質量部以下であってよい。これらの観点から、第１の物質の量は、０．１～５０質量部であってよい。
　本実施形態に係る被覆樹脂粒子の製造方法は、被覆工程で得られた粒子に脱水処理を施す脱水工程（乾燥工程）を備えてよい。脱水工程では、被覆工程で得られた粒子における水分の少なくとも一部を除去する。脱水工程では、加熱処理を施すことにより脱水処理を施してよい。加熱温度は、例えば１００～１５０℃であってよい。
　本実施形態に係る粒子表面積の調整方法は、本実施形態に係る被覆樹脂粒子の粒子表面積の調整方法である。本実施形態に係る粒子表面積の調整方法では、第１の物質と、当該第１の物質と重合反応する第２の物質とを吸水状態の吸水性樹脂粒子の表面で重合反応させて、吸水性樹脂粒子の少なくとも一部を被覆する被覆部を得る被覆工程における吸水状態の吸水性樹脂粒子の膨張度に基づき、吸水性樹脂粒子及び被覆部を有する被覆樹脂粒子の表面積を調整する。
　本実施形態に係る粒子表面積の調整方法によれば、第１の物質と第２の物質との重合反応物である被覆部によって吸水性樹脂粒子（被コーティング体）の少なくとも一部を被覆するに際して吸水状態の吸水性樹脂粒子の膨張度を調整することにより被覆樹脂粒子の表面積を容易に調整できる。本実施形態に係る被覆樹脂粒子の調整方法によれば、例えば粒子径３００～４００μｍの被覆樹脂粒子の表面積を容易に調整できる。被覆工程における吸水状態の吸水性樹脂粒子の膨張度は、本実施形態に係る被覆樹脂粒子の製造方法に関して上述した膨張度（例えば１．５倍以上）に調整できる。
　以下、実験例を用いて本発明の内容を更に説明するが、本発明は以下の実験例に限定されるものではない。
＜評価用粒子の作製＞
（実験例Ａ１）
　還流冷却器、滴下ロート、窒素ガス導入管、及び、撹拌機（翼径５ｃｍの４枚傾斜パドル翼を２段有する撹拌翼）を備えた内径１１ｃｍ、内容積２Ｌの丸底円筒型セパラブルフラスコを準備した。このフラスコに、ｎ－ヘプタン２９３ｇ、及び、無水マレイン酸変性エチレン・プロピレン共重合体（分散剤、三井化学株式会社製、ハイワックス１１０５Ａ）０．７３６ｇを添加することにより混合物を得た。この混合物を撹拌しつつ８０℃まで昇温することにより分散剤をｎ－ヘプタンに溶解させた後、混合物を５０℃まで冷却した。
　次に、内容積３００ｍＬのビーカーに、水溶性エチレン性不飽和単量体として８０．５質量％のアクリル酸水溶液９２．０ｇ（アクリル酸：１．０３モル）を入れた。続いて、外部より冷却しつつ、２０．９質量％の水酸化ナトリウム水溶液１４７．７ｇをビーカー内に滴下することにより７５モル％のアクリル酸を中和した。その後、増粘剤としてヒドロキシエチルセルロース０．０９２ｇ（住友精化株式会社製、ＨＥＣ　ＡＷ－１５Ｆ）、水溶性ラジカル重合開始剤として過硫酸カリウム０．０７３６ｇ（０．２７２ミリモル）、内部架橋剤としてエチレングリコールジグリシジルエーテル０．０１０ｇ（０．０５７ミリモル）を加えた後に溶解させることにより第１段目の水溶液を調製した。
　そして、上述の第１段目の水溶液を上述のセパラブルフラスコに添加した後、１０分間撹拌した。その後、ｎ－ヘプタン６．６２ｇにショ糖ステアリン酸エステル（界面活性剤、三菱化学フーズ株式会社製、リョートーシュガーエステルＳ－３７０、ＨＬＢ：３）０．７３６ｇを溶解することにより得られた界面活性剤溶液をセパラブルフラスコに添加することにより反応液を得た。そして、撹拌機の回転数５５０ｒｐｍで反応液を撹拌しながら系内を窒素で充分に置換した。その後、セパラブルフラスコを７０℃の水浴に浸漬させることにより反応液を昇温し、重合反応を６０分間進行させることにより第１段目の重合スラリー液を得た。
　次に、内容積５００ｍＬの別のビーカーに水溶性エチレン性不飽和単量体として８０．５質量％のアクリル酸水溶液１２８．８ｇ（アクリル酸：１．４３モル）を入れた。続いて、外部より冷却しつつ、２７質量％の水酸化ナトリウム水溶液１５９．０ｇをビーカー内に滴下することにより７５モル％のアクリル酸を中和した。その後、アクリル酸水溶液が入ったビーカーに、水溶性ラジカル重合開始剤として過硫酸カリウム０．１０３ｇ（０．３８１ミリモル）と、内部架橋剤としてエチレングリコールジグリシジルエーテル０．０１１６ｇ（０．０６７ミリモル）とを加えた後に溶解させることにより第２段目の水性液を調製した。
　撹拌機の回転数を１０００ｒｐｍとして撹拌しながら、上述のセパラブルフラスコ内の第１段目の重合スラリー液を２５℃に冷却し、上述の第２段目の水溶液の全量を上述の第１段目の重合スラリー液に添加した。続いて、フラスコ内を窒素で３０分間置換した後、再度、フラスコを７０℃の水浴に浸漬して反応液を昇温し、第２段目の重合反応を６０分間行うことにより含水ゲル状重合体を得た。
　その後、１２５℃に設定した油浴に上記フラスコを浸漬し、ｎ－ヘプタンと水との共沸蒸留により２５７．７ｇの水を系外へ抜き出した。次いで、上記フラスコを引き上げた後、その下部が油浴にわずかに接している状態で内温を８３℃に調節した。その後、フラスコに表面架橋剤として２質量％のエチレングリコールジグリシジルエーテル水溶液４．４２ｇ（０．５０７ミリモル）を添加した後、内温を８３℃で２時間保持した。
　その後、１２５℃に設定した油浴にフラスコを再度浸漬して昇温し、ｎ－ヘプタンと水との共沸蒸留により、ｎ－ヘプタンを還流しながら２４５ｇの水を系外へ抜き出した。そして、ｎ－ヘプタンを１２５℃にて蒸発させて乾燥させることによって乾燥物（重合物）を得た。この乾燥物を目開き８５０μｍの篩に通過させることにより、球状粒子が凝集した形態の吸水性樹脂粒子Ａ（被コーティング体）２３６．８ｇを得た。下記第１の物質と接触させる前における吸水性樹脂粒子Ａの液状成分の含有率は１０質量％であった。液状成分の含有率の算出方法については後述する。
　第１の物質であるモノマー種Ａの溶液として、ポリエーテルポリオール（第一工業製薬株式会社製、ＤＫポリオール３８１７）４．０ｇ及びイオン交換水７６．０ｇの混合液（ポリオール水溶液）８０．０ｇを調製した。また、第２の物質であるモノマー種Ｂの溶液として、トリレン－２，４－ジイソシアナート１．９ｇ及びアセトン１７．１ｇの混合液（イソシアネート溶液）１９．０ｇを調製した。
　次に、還流冷却器、滴下ロート、窒素ガス導入管、及び、撹拌機（翼径５ｃｍの４枚傾斜パドル翼を２段有する撹拌翼）を備えた内径１１ｃｍ、内容積２Ｌの丸底円筒型セパラブルフラスコを準備した。このフラスコに、上述の吸水性樹脂粒子Ａ（逆相懸濁重合法により得られた吸水性樹脂粒子、被コーティング体）４０．０ｇを加えた。その後、炭化水素分散媒としてｎ－ヘプタン４８０ｇを加えた後に１０００ｒｐｍで撹拌することにより、分散体である分散液を得た。
　この分散液を撹拌しつつ上述のモノマー種Ａの溶液８０ｇを添加することにより、吸水性樹脂粒子Ａをモノマー種Ａと接触させた後、室温で３０分間撹拌した。第１の物質であるモノマー種Ａと吸水性樹脂粒子Ａとを接触させた後の吸水状態における吸水性樹脂粒子Ａの膨張度は３．２倍であった。膨張度の算出方法については後述する。
　続いて、上述のモノマー種Ｂの溶液１９．０ｇを添加した後、室温で１２０分間撹拌することにより、吸水性樹脂粒子Ａの表面で逐次重合反応を進行させて反応物を得た。
　その後、１２５℃の油浴で反応物を昇温し、ｎ－ヘプタンと水との共沸蒸留により、ｎ－ヘプタンを還流しながら７６ｇの水を系外へ抜き出した。そして、ｎ－ヘプタンを１２５℃にて蒸発させさせることによって乾燥物（重合物）を得た。この乾燥物を目開き８５０μｍの篩に通過させることにより、ポリウレタンにより吸水性樹脂粒子Ａがコーティングされた被覆樹脂粒子Ａ１を３８．２ｇ得た。
（実験例Ａ２）
　第１の物質であるモノマー種Ａの溶液をポリエーテルポリオール（第一工業製薬株式会社製、ＤＫポリオール３８１７）４ｇ及びイオン交換水３６ｇの混合液４０ｇに変更したこと以外は実験例Ａ１と同様に行うことにより被覆樹脂粒子Ａ２を作製した。第１の物質であるモノマー種Ａと吸水性樹脂粒子Ａとを接触させた後の吸水状態における吸水性樹脂粒子Ａの膨張度は２．１倍であった。
（実験例Ｂ１）
　撹拌機（翼径５ｃｍの４枚傾斜パドル翼を２段有する撹拌翼）を備えた内径１１ｃｍ、内容積２Ｌの丸底円筒型セパラブルフラスコに５０９．７１ｇ（７．０７モル）の１００％アクリル酸を入れた。このアクリル酸を撹拌しながら、セパラブルフラスコ内にイオン交換水４３６．４７ｇを加えた。その後、氷浴（１℃）下で４４４．６８ｇの４８質量％水酸化ナトリウムを滴下することにより単量体濃度４５．０８質量％のアクリル酸部分中和液（中和率：７５．４４モル％）１３９０．８６ｇを調製した。本操作を３回繰り返し、後述の重合に用いた。
　上述のアクリル酸部分中和液２７８１．７２ｇにイオン交換水４０６．８９ｇ及びポリエチレングリコールジアクリレート（ｎ＝９）２．９０ｇ（５．５７６ミリモル）を加えて反応液（単量体水溶液）を得た。次に、この反応液を窒素ガス雰囲気下で３０分間窒素ガス置換した。次いで、温度計、窒素吹込み管、開閉可能な蓋、２本のシグマ型羽根及びジャケットを備えるステンレス製双腕型ニーダーに上述の反応液を供給した後、反応液を３０℃に保ちながら系を窒素ガス置換した。続いて、反応液を撹拌しながら、２．０質量％の過硫酸ナトリウム水溶液９２．６３ｇ（７．７８０ミリモル）及び０．５質量％のＬ－アスコルビン酸水溶液１５．８５ｇを加えた。約１分後に温度が上昇し始め、重合が開始した。６分後に重合中の最高温度は９３℃を示した。その後、ジャケット温度を６０℃に保ちながら撹拌し続け、重合を開始してから６０分後に含水ゲルを取り出した。得られた含水ゲルを喜連ローヤル社製のミートチョッパー１２ＶＲ－７５０ＳＤＸに順次投入し、細分化した。ミートチョッパーの尖端に位置するプレートの穴の径は６．４ｍｍであった。
　この細分化された粒子状含水ゲルを目開き０．８ｃｍ×０．８ｃｍの金網上に広げた後、１６０℃で６０分間熱風乾燥することによって乾燥物を得た。
　次いで、遠心粉砕機（Ｒｅｔｓｃｈ社製、ＺＭ２００、スクリーン口径１ｍｍ、１２０００ｒｐｍ）を用いて乾燥物を粉砕し、不定形破砕状の吸水性樹脂粒子を得た。さらに、この吸水性樹脂粒子を目開き８５０μｍの金網、目開き２５０μｍの金網及び目開き１８０μｍの金網で分級することにより、目開き８５０μｍの金網を通過し、かつ、目開き２５０μｍの金網を通過しなかった分画である吸水性樹脂粒子Ｂを得た。第１の物質であるモノマー種Ａと接触させる前における吸水性樹脂粒子Ｂの液状成分の含有率は５質量％であった。液状成分の含有率の算出方法については後述する。
　この吸水性樹脂粒子Ｂ（水溶液重合法により得られた吸水性樹脂粒子）を被コーティング体として用いたこと以外は実験例Ａ１と同様に行うことによって当該吸水性樹脂粒子Ｂをポリウレタンによりコーティングすることで被覆樹脂粒子Ｂ１を作製した。第１の物質であるモノマー種Ａと吸水性樹脂粒子Ｂとを接触させた後の吸水状態における吸水性樹脂粒子Ｂの膨張度は３．１倍であった。
＜吸水状態における吸水性樹脂粒子の膨張度の算出＞
　第１の物質であるモノマー種Ａと吸水性樹脂粒子とを接触させた後の吸水状態における吸水性樹脂粒子の膨張度（２５℃）は、第１の物質と接触させる前における吸水性樹脂粒子の液状成分の含有率（２５℃）の測定結果を用いて下記の手順で算出した。
　液状成分の含有率は次の手順で測定した。１０５℃に設定した熱風乾燥機（ＦＶ－３２０、ＡＤＶＡＮＴＥＣ製）で吸水性樹脂粒子（被コーティング体として使用しない粒子）２．０００ｇを２時間加熱した。吸水性樹脂粒子の減少質量［ｇ］を、吸水性樹脂粒子に含まれる液状成分の含有量［ｇ］であると判断し、下記式（１）によって液状成分の含有率を得た。
　式（１）：　第１の物質と接触させる前における吸水性樹脂粒子の液状成分の含有率［質量％］＝｛吸水性樹脂粒子の減少質量［ｇ］／吸水性樹脂粒子の質量（２．０００ｇ）｝×１００
　吸水状態における吸水性樹脂粒子の膨張度は次の手順で算出した。まず、第１の物質と接触させる前における吸水性樹脂粒子を準備した後、下記式（２）により当該吸水性樹脂粒子における液状成分の初期含有量を算出した。次に、下記式（３）により吸水性樹脂粒子の純分（液状成分を除く吸水性樹脂粒子の質量）を算出した。そして、下記式（４）により吸水状態における吸水性樹脂粒子の膨張度を算出した。
　式（２）：　吸水性樹脂粒子における液状成分の初期含有量［ｇ］＝｛第１の物質と接触させる前における吸水性樹脂粒子の質量［ｇ］×吸水性樹脂粒子の液状成分の含有率［質量％］｝／１００
　式（３）：　吸水性樹脂粒子の純分［ｇ］＝第１の物質と接触させる前における吸水性樹脂粒子の質量［ｇ］－吸水性樹脂粒子における液状成分の初期含有量［ｇ］
　式（４）：　膨張度［倍］＝吸水状態における吸水性樹脂粒子の質量［ｇ］／吸水性樹脂粒子の純分［ｇ］
　例えば、上述の実験例Ａ１において、第１の物質であるモノマー種Ａの溶液における溶媒（イオン交換水７６．０ｇ）の全てが吸水性樹脂粒子Ａに吸収されたとみなし、第１の物質であるモノマー種Ａと吸水性樹脂粒子Ａとを接触させた後の吸水状態における吸水性樹脂粒子Ａは、吸水性樹脂粒子Ａの純分３６．０ｇと、吸水性樹脂粒子Ａにおける液状成分の初期含有量４．０ｇと、モノマー種Ａの溶液から供給されたイオン交換水７６．０ｇとを含有しており、膨張度は「（３６．０ｇ＋４．０ｇ＋７６．０ｇ）／３６．０ｇ＝３．２倍」であった。
＜粒子の表面観察＞
　上述の被覆樹脂粒子Ａ１、Ａ２及びＢ１、並びに、上述の吸水性樹脂粒子Ａ及びＢを評価用粒子として準備した。走査電子顕微鏡（ＳＥＭ、日本電子株式会社（ＪＥＯＬ）製、ＪＳＭ－６３９０ＬＡ）を用いて評価用粒子の状態を観察した。サンプルステージ上に両面カーボンテープの一方面を貼り付けた後、両面カーボンテープの一方面の他方面に評価用粒子を載せた。加速電圧１５ｋＶ、動作距離１０ｍｍに設定し、評価用粒子を５００倍の倍率で観察した。図２及び図３は、被覆樹脂粒子及び吸水性樹脂粒子のＳＥＭ写真を示す図面である。図２（ａ）は、被覆樹脂粒子Ａ１のＳＥＭ写真を示す図面であり、図２（ｂ）は、被覆樹脂粒子Ａ２のＳＥＭ写真を示す図面であり、図２（ｃ）は、吸水性樹脂粒子ＡのＳＥＭ写真を示す図面である。図３（ａ）は、被覆樹脂粒子Ｂ１のＳＥＭ写真を示す図面であり、図３（ｂ）は、吸水性樹脂粒子ＢのＳＥＭ写真を示す図面である。図２によれば、表面に襞状の突起を有する被覆樹脂粒子Ａ１及びＡ２の比表面積が吸水性樹脂粒子Ａの比表面積よりも大きいことが推測され、後述の比表面積の測定において比表面積を確認した。この結果から、図３によれば、表面に襞状の突起を有する被覆樹脂粒子Ｂ１の比表面積が吸水性樹脂粒子Ｂの比表面積よりも大きいことが推測される。
＜比表面積の測定＞
　上述の被覆樹脂粒子Ａ１，Ａ２、及び、吸水性樹脂粒子Ａを準備した。これらの粒子を目開き４００μｍの篩及び目開き３００μｍの篩にかけることにより、目開き４００μｍの篩を通過し、目開き３００μｍの篩上に残存する粒子を比表面積測定用の試料として得た。この試料を１００℃で１６時間加熱真空排気の脱気条件で乾燥した。その後、比表面積測定装置（ＡＵＴＯＳＯＲＢ－１、カンタクローム社製）により、吸着ガスとしてクリプトンガスを用いる方法で温度７７Ｋにて吸着等温線を測定し、多点ＢＥＴプロットから比表面積（ＢＥＴ比表面積）を求めた。
　吸水性樹脂粒子Ａの比表面積は０．０３６ｍ２／ｇであった。吸水性樹脂粒子Ａを被覆部で被覆することにより得られる被覆樹脂粒子の比表面積として、被覆樹脂粒子Ａ１の比表面積は０．０６０ｍ２／ｇであり、被覆樹脂粒子Ａ２の比表面積は０．０４６ｍ２／ｇであった。
　１…被覆樹脂粒子、１ａ…樹脂粒子、１ｂ…コーティング層。

Claims (5)

  1. 　第１の物質と、当該第１の物質と重合反応する第２の物質とを吸水状態の吸水性樹脂粒子の表面で重合反応させて、前記吸水性樹脂粒子の少なくとも一部を被覆する被覆部を得る被覆工程を備える、被覆樹脂粒子の製造方法。
  2. 　前記吸水状態の吸水性樹脂粒子の膨張度が１．５倍以上である、請求項１に記載の被覆樹脂粒子の製造方法。
  3. 　前記吸水性樹脂粒子が、（メタ）アクリル酸及びその塩からなる群より選ばれる少なくとも一種に由来する構造単位を有する、請求項１又は２に記載の被覆樹脂粒子の製造方法。
  4. 　前記第１の物質がポリオールを含み、前記第２の物質がポリイソシアネートを含む、請求項１～３のいずれか一項に記載の被覆樹脂粒子の製造方法。
  5. 　第１の物質と、当該第１の物質と重合反応する第２の物質とを吸水状態の吸水性樹脂粒子の表面で重合反応させて、前記吸水性樹脂粒子の少なくとも一部を被覆する被覆部を得る被覆工程における前記吸水状態の吸水性樹脂粒子の膨張度に基づき、前記吸水性樹脂粒子及び前記被覆部を有する被覆樹脂粒子の表面積を調整する、粒子表面積の調整方法。
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Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP4321558A1 (en) * 2021-05-18 2024-02-14 Sumitomo Seika Chemicals Co., Ltd. Coated resin particles and method for producing coated resin particles
WO2023100479A1 (ja) * 2021-11-30 2023-06-08 住友精化株式会社 吸水性樹脂粒子及び吸収体
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WO2023119798A1 (ja) * 2021-12-21 2023-06-29 住友精化株式会社 被覆樹脂粒子、吸水性樹脂組成物及び吸収体
WO2023233925A1 (ja) * 2022-05-30 2023-12-07 住友精化株式会社 吸収体及び吸収性物品

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS63118308A (ja) * 1986-11-06 1988-05-23 Nippon Synthetic Chem Ind Co Ltd:The 高吸水性樹脂の製造法
JPH1157465A (ja) * 1997-08-22 1999-03-02 Sanyo Chem Ind Ltd 畳用調湿材およびそれを用いた畳
JPH11347402A (ja) * 1998-04-10 1999-12-21 Sanyo Chem Ind Ltd 吸水剤及びその製法
JP2010013502A (ja) * 2008-07-01 2010-01-21 Sanyo Chem Ind Ltd 樹脂粒子

Family Cites Families (71)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS56115259A (en) * 1980-02-19 1981-09-10 Kuraray Co Surface coated high water absorbing resin molding
JPS56159232A (en) * 1980-05-12 1981-12-08 Kuraray Co Ltd Powdery high water-absorption resin for surface coating
JPS57168921A (en) * 1981-04-10 1982-10-18 Sumitomo Chem Co Ltd Production of highly water-absorbing polymeric material having improved water-absorption rate
ES535037A0 (es) * 1983-08-10 1985-12-01 Kao Corp Un procedimiento para preparar una resina absorbente de agua y muy reactiva
CA1280398C (en) * 1986-02-05 1991-02-19 Hideharu Shirai Water-absorbent resin and process for producing the same
JPS63132901A (ja) * 1986-11-25 1988-06-04 Lion Corp 吸水性樹脂の製造方法
JPS63154766A (ja) * 1986-12-18 1988-06-28 Sumitomo Chem Co Ltd 高吸水性樹脂組成物
JP2530668B2 (ja) * 1987-11-12 1996-09-04 株式会社日本触媒 改良された吸水性樹脂の製造法
DE3741157A1 (de) * 1987-12-04 1989-06-15 Stockhausen Chem Fab Gmbh Verfahren zur agglomerierung wasserquellbarer polymerer durch schmelz (sinter-)granulation mit pulverfoermigen substanzen und verwendung der granulate
JPH01261250A (ja) * 1988-04-08 1989-10-18 Tsuruga Cement Kk 高吸水性樹脂を用いたセメント・コンクリートおよびモルタルの混和材料
JP2579814B2 (ja) * 1989-03-16 1997-02-12 三洋化成工業株式会社 吸水剤およびその製造方法
JPH03285918A (ja) * 1990-03-31 1991-12-17 Tokai Rubber Ind Ltd 吸水性樹脂の製法
JPH04298516A (ja) * 1991-03-27 1992-10-22 Sanyo Chem Ind Ltd 水膨潤性複合樹脂組成物
DE4138408A1 (de) * 1991-11-22 1993-05-27 Cassella Ag Hydrophile, hochquellfaehige hydrogele
JP2807126B2 (ja) * 1992-06-30 1998-10-08 積水化成品工業株式会社 接着性吸水性樹脂粒子
JPH07309971A (ja) * 1994-05-19 1995-11-28 Arakawa Chem Ind Co Ltd 吸水性樹脂の改質方法
DE4426008A1 (de) * 1994-07-22 1996-01-25 Cassella Ag Hydrophile, hochquellfähige Hydrogele
JP3071680B2 (ja) * 1994-10-24 2000-07-31 三洋化成工業株式会社 吸水性樹脂分散体
JP3603970B2 (ja) * 1994-11-21 2004-12-22 株式会社日本触媒 粉末の吸水性樹脂組成物の製造方法
JP3060095B2 (ja) * 1995-05-31 2000-07-04 三洋化成工業株式会社 ウレタン樹脂組成物、吸水材および吸放湿材
DE19801933A1 (de) * 1998-01-20 1999-07-22 Clariant Gmbh Verkapselte Hydrogele
JP3822812B2 (ja) * 2000-10-23 2006-09-20 株式会社日本触媒 吸水剤およびその製造方法
JP2003088553A (ja) * 2001-09-19 2003-03-25 Sumitomo Seika Chem Co Ltd 吸収体およびそれを用いた吸収性物品
JP2003183528A (ja) * 2001-12-21 2003-07-03 San-Dia Polymer Ltd 吸収剤、これを用いてなる吸収体及び吸収性物品
JP4071030B2 (ja) * 2002-04-11 2008-04-02 花王株式会社 表面疎水化吸水性ポリマー粒子
EP1510229B1 (en) * 2003-08-27 2010-07-14 Nippon Shokubai Co., Ltd. Process for production of surface-treated particulate water-absorbent resin
JP3648553B2 (ja) * 2003-08-29 2005-05-18 サンダイヤポリマー株式会社 吸収性樹脂粒子、これを用いてなる吸収体及び吸収性物品
EP1518566B1 (en) * 2003-09-25 2008-04-09 The Procter & Gamble Company Absorbent articles comprising superabsorbent polymer particles having a non-covalently bonded surface coating
US7173086B2 (en) 2003-10-31 2007-02-06 Stockhausen, Inc. Superabsorbent polymer with high permeability
US7879923B2 (en) * 2004-12-10 2011-02-01 Nippon Shokubai Co., Ltd. Method for surface-treatment of water absorbent resin
JP4476822B2 (ja) 2005-01-20 2010-06-09 旭化成ケミカルズ株式会社 アンモニウム塩含有吸水性樹脂、及びその製造方法
WO2006082239A2 (en) * 2005-02-04 2006-08-10 Basf Aktiengesellschaft Water-absorbing material having a coating of elastic film-forming polymers
EP1878761B1 (en) * 2005-03-14 2018-10-17 Nippon Shokubai Co.,Ltd. Water absorbent and process for producing the same
JP5405740B2 (ja) * 2005-05-16 2014-02-05 住友精化株式会社 吸水性樹脂粒子の製造方法、それにより得られる吸水性樹脂粒子、およびそれを用いた吸収体および吸収性物品
JP5270921B2 (ja) * 2005-09-16 2013-08-21 株式会社日本触媒 吸水剤の製造方法
DE102006019157A1 (de) * 2006-04-21 2007-10-25 Stockhausen Gmbh Herstellung von hochpermeablen, superabsorbierenden Polymergebilden
JP4904089B2 (ja) * 2006-05-31 2012-03-28 大王製紙株式会社 吸収性物品及びその製造方法
US7935860B2 (en) * 2007-03-23 2011-05-03 Kimberly-Clark Worldwide, Inc. Absorbent articles comprising high permeability superabsorbent polymer compositions
JP2008264672A (ja) 2007-04-19 2008-11-06 Nippon Shokubai Co Ltd 粉体の造粒方法
JP4758960B2 (ja) * 2007-08-02 2011-08-31 サンダイヤポリマー株式会社 吸収性樹脂粒子及び吸収性物品
JP5149654B2 (ja) * 2008-02-28 2013-02-20 サンダイヤポリマー株式会社 吸収性樹脂粒子及び吸収性物品
JP5528714B2 (ja) 2009-03-02 2014-06-25 株式会社日本触媒 吸水性樹脂の製造方法
JP2010241975A (ja) * 2009-04-07 2010-10-28 San-Dia Polymer Ltd 吸収性樹脂粒子、これを含む吸収体及び吸収性物品
WO2011078298A1 (ja) 2009-12-24 2011-06-30 株式会社日本触媒 ポリアクリル酸系吸水性樹脂粉末及びその製造方法
US8623783B2 (en) * 2010-02-08 2014-01-07 Lg Chem, Ltd. Absorbent resin surface-modified with cationic polymer compound
JP5473680B2 (ja) * 2010-03-04 2014-04-16 Ｓｄｐグローバル株式会社 吸収性樹脂粒子及びこの製造方法
BR112012027406B1 (pt) * 2010-04-26 2021-02-09 Nippon Shokubai Co., Ltd. resina absorvedora de água tipo ácido poliacrílico (sal), material sanitário e método para produzir a referida resina
JP5485805B2 (ja) * 2010-06-15 2014-05-07 住友精化株式会社 吸水性樹脂
WO2012014749A1 (ja) * 2010-07-28 2012-02-02 住友精化株式会社 吸水性樹脂の製造方法
CN103154043B (zh) * 2010-10-18 2015-04-22 住友精化株式会社 吸水性树脂颗粒的制造方法和吸水性树脂颗粒
BR112013014656A2 (pt) * 2010-12-16 2016-09-27 Sumitomo Seika Chemicals método para a produção de resina absorvente de água
JP2013203761A (ja) * 2012-03-27 2013-10-07 Kao Corp 改質吸水性樹脂粒子
JP2013213083A (ja) * 2012-03-30 2013-10-17 Kao Corp 改質吸水性樹脂粒子
KR102105733B1 (ko) * 2012-10-03 2020-04-28 가부시키가이샤 닛폰 쇼쿠바이 흡수제 및 그의 제조 방법
US20150314034A1 (en) 2012-12-21 2015-11-05 Basf Se Process for producing water-absorbing polymer particles
WO2014119553A1 (ja) * 2013-01-29 2014-08-07 株式会社日本触媒 吸水性樹脂材料及びその製造方法
JP2016112474A (ja) * 2013-04-05 2016-06-23 株式会社日本触媒 吸水剤の製造方法
US9375507B2 (en) * 2013-04-10 2016-06-28 Evonik Corporation Particulate superabsorbent polymer composition having improved stability
US9302248B2 (en) * 2013-04-10 2016-04-05 Evonik Corporation Particulate superabsorbent polymer composition having improved stability
JP6169926B2 (ja) * 2013-08-30 2017-07-26 株式会社日本触媒 吸水性樹脂の微粉砕方法及び耐塩性に優れた吸水性樹脂
DE202014011225U1 (de) * 2013-12-03 2018-08-31 Lg Chem. Ltd. Superabsorbierendes Polymer
MY177389A (en) 2014-05-23 2020-09-14 Sdp Global Co Ltd Water-absorbing resin particles, absorber comprising same, and absorbent article
JP5689204B1 (ja) * 2014-07-11 2015-03-25 住友精化株式会社 吸水性樹脂の製造方法、吸水性樹脂、吸水剤、吸収性物品
JP5766344B1 (ja) * 2014-07-11 2015-08-19 住友精化株式会社 吸水性樹脂及び吸収性物品
JP2016069418A (ja) * 2014-09-26 2016-05-09 株式会社日本触媒 ポリ（メタ）アクリル酸（塩）系吸水性樹脂の製造方法
KR101949995B1 (ko) * 2015-07-06 2019-02-19 주식회사 엘지화학 고흡수성 수지의 제조 방법 및 이로부터 제조된 고흡수성 수지
JP2017206646A (ja) * 2016-05-20 2017-11-24 Ｓｄｐグローバル株式会社 吸水性樹脂粒子、これを含有してなる吸収体及び吸収性物品
JP2018053041A (ja) * 2016-09-27 2018-04-05 森下仁丹株式会社 複数の吸水性ポリマー粒子、並びに複数の吸水性ポリマー粒子の製造方法
KR102167661B1 (ko) * 2017-02-10 2020-10-19 주식회사 엘지화학 고흡수성 수지 및 이의 제조 방법
US20220015958A1 (en) * 2018-12-12 2022-01-20 Sumitomo Seika Chemicals Co., Ltd. Water absorbent resin particles and absorbent article
CN113166436B (zh) * 2018-12-12 2024-04-30 住友精化株式会社 吸水性树脂颗粒及吸收性物品

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS63118308A (ja) * 1986-11-06 1988-05-23 Nippon Synthetic Chem Ind Co Ltd:The 高吸水性樹脂の製造法
JPH1157465A (ja) * 1997-08-22 1999-03-02 Sanyo Chem Ind Ltd 畳用調湿材およびそれを用いた畳
JPH11347402A (ja) * 1998-04-10 1999-12-21 Sanyo Chem Ind Ltd 吸水剤及びその製法
JP2010013502A (ja) * 2008-07-01 2010-01-21 Sanyo Chem Ind Ltd 樹脂粒子

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