WO2022124137A1 - Resin particle composition - Google Patents

Resin particle composition Download PDF

Info

Publication number
WO2022124137A1
WO2022124137A1 PCT/JP2021/043855 JP2021043855W WO2022124137A1 WO 2022124137 A1 WO2022124137 A1 WO 2022124137A1 JP 2021043855 W JP2021043855 W JP 2021043855W WO 2022124137 A1 WO2022124137 A1 WO 2022124137A1
Authority
WO
WIPO (PCT)
Prior art keywords
particle composition
water
resin particle
fixing member
sieve
Prior art date
Application number
PCT/JP2021/043855
Other languages
French (fr)
Japanese (ja)
Inventor
友花 田邉
Original Assignee
住友精化株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 住友精化株式会社 filed Critical 住友精化株式会社
Priority to CN202180080826.1A priority Critical patent/CN116568761B/en
Priority to JP2022568204A priority patent/JPWO2022124137A1/ja
Publication of WO2022124137A1 publication Critical patent/WO2022124137A1/en

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
    • B01J20/22—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising organic material
    • B01J20/26—Synthetic macromolecular compounds
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L101/00—Compositions of unspecified macromolecular compounds
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L101/00—Compositions of unspecified macromolecular compounds
    • C08L101/12—Compositions of unspecified macromolecular compounds characterised by physical features, e.g. anisotropy, viscosity or electrical conductivity
    • C08L101/14—Compositions of unspecified macromolecular compounds characterised by physical features, e.g. anisotropy, viscosity or electrical conductivity the macromolecular compounds being water soluble or water swellable, e.g. aqueous gels

Definitions

  • the present invention relates to a resin particle composition.
  • the water-absorbent resin particles having the property of absorbing and retaining water which is an essential element in daily life, are sanitary materials such as paper diapers and sanitary products, agricultural and horticultural materials such as water retention agents and soil improvers, and stoppers. It is widely used in fields such as industrial materials such as water agents and anti-condensation agents. Since the water-absorbent resin particles are usually powders having no adhesive force, they are used as an absorber formed in a sandwich shape by spraying the water-absorbent resin particles on a fibrous base material such as a non-woven fabric in the above application. At this time, in order to fix the water-absorbent resin particles to the base material, a method of spraying the water-absorbent resin particles on the fibrous base material coated with the adhesive is performed (for example, Patent Document 1).
  • An object of the present invention is to provide a resin particle composition that does not easily fall off from an absorber.
  • the resin particle composition of the present invention has water-absorbent resin particles and a fixing member layer, and after the caking test performed in the order of (1) to (5) below, at least the particles are placed on a sieve having an opening of 850 ⁇ m. Some remain.
  • a circular release paper having a diameter of 50 mm is laid on the bottom of a circular stainless steel petri dish having an inner diameter of 52 mm, and 2.0 g of a resin particle composition having a particle size of less than 850 ⁇ m is sprayed on the release paper.
  • a measurement sample is obtained by stacking a circular release paper having a diameter of 50 mm, a circular stainless steel petri dish having an outer diameter of 50 mm and a mass of 20 g, and a cylindrical weight having a diameter of 45 mm, 780 g, on the sprayed resin particle composition in this order.
  • the measurement sample is dried at 80 ° C. for 1 hour with a hot air dryer, and then allowed to cool to room temperature.
  • the resin particle composition is removed from the release paper after cooling and recovered, and the entire amount of the recovered resin particle composition is placed on a sieve having an opening of 850 ⁇ m. (5) After shaking the above sieve with a low-tap type sieve shaker for 5 seconds, it is confirmed whether the resin particle composition remains on the sieve.
  • the resin particle composition preferably has a caking index of 20% or more, which is measured by the caking test and is represented by the following formula.
  • Caking index (%) [Mass of resin particle composition remaining on a sieve with an opening of 850 ⁇ m / (Resin particle composition remaining on a sieve with an opening of 850 ⁇ m and a resin particle composition passing through a sieve with an opening of 850 ⁇ m) Total mass)] x 100
  • the fixing member layer may contain at least one selected from the group consisting of an ethylene-based polymer, a polyether-based polymer, a polyamide-based polymer, a polyurethane-based polymer, and a polyester-based polymer.
  • the amount of the fixing member may be 0.01 to 10 parts by mass with respect to 100 parts by mass of the water-absorbent resin particles.
  • the resin particle composition may have a physiological saline water retention amount of 30 g / g or more.
  • the present invention provides a resin particle composition that does not easily fall off from the absorber.
  • 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.
  • Water-soluble means that it exhibits a solubility in water of 5% by mass or more at 25 ° C.
  • Room temperature means 25 ⁇ 2 ° C.
  • layer includes not only a structure having a shape formed on the entire surface but also a structure having a shape partially formed when observed as a plan view.
  • the resin particle composition according to the present embodiment has water-absorbent resin particles and a fixing member layer.
  • the resin particle composition has a caking property measured in the caking test performed in the order of (1) to (5) below. Having a caking property means that at least a part of the particles remains on the sieve having an opening of 850 ⁇ m used after the step (5) of the caking test below.
  • a circular release paper having a diameter of 50 mm is laid on the bottom of a circular stainless steel petri dish having an inner diameter of 52 mm, and 2.0 g of a resin particle composition having a particle size of less than 850 ⁇ m is sprayed on the release paper.
  • a measurement sample is obtained by stacking a circular release paper having a diameter of 50 mm, a circular stainless steel petri dish having an outer diameter of 50 mm and a mass of 20 g, and a cylindrical weight having a diameter of 45 mm, 780 g, on the sprayed resin particle composition in this order. As a result, the resin particle composition is pressurized at 4000 Pa.
  • the measurement sample is dried at 80 ° C. for 1 hour with a hot air dryer, and then allowed to cool to room temperature.
  • the resin particle composition is removed from the release paper after cooling and recovered, and the entire amount of the recovered resin particle composition is placed on a sieve having an opening of 850 ⁇ m. (5) After shaking the above sieve with a low-tap type sieve shaker for 5 seconds, it is confirmed whether the resin particle composition remains on the sieve.
  • the resin particle composition according to the present embodiment has the caking property measured in the caking test, for example, when the absorber is produced, the resin particle composition and the fibrous base material are overlapped and heated under pressure. Therefore, it is possible to immobilize the resin particle composition on the fibrous base material without using a separate adhesive.
  • the above caking test is a direct index of the binding property between the resin particle compositions, but the resin particle composition having such caking property is also bonded to the fibrous substrate by pressure heating. It is possible to wear it.
  • the resin particle composition according to the present embodiment preferably has a caking index of 20% or more represented by the following formula.
  • the caking index is measured by measuring the mass of the resin particle composition remaining on the sieve having an opening of 850 ⁇ m and the mass of the resin particle composition passing through the sieve having an opening of 850 ⁇ m after the step (5) of the caking test.
  • Can be calculated by Caking index (%) [Mass of resin particle composition remaining on a sieve with an opening of 850 ⁇ m / (Resin particle composition remaining on a sieve with an opening of 850 ⁇ m and a resin particle composition passing through a sieve with an opening of 850 ⁇ m) Total mass)] x 100
  • the caking index of the resin particle composition according to the present embodiment is 20% or more, 25% or more, 30% or more, 35% or more, 40% or more, 45% or more, 50% or more, 55% or more, 60% or more, It may be 65% or more, 70% or more, 75% or more, 78% or more, 80% or more, 85% or more, 90% or more, or 95% or more.
  • the caking index of the resin particle composition according to the present embodiment may be 100% or less, 99% or less, 98% or less, 97% or less, or 95% or less.
  • the resin particle composition according to the present embodiment has water-absorbent resin particles and a fixing member layer.
  • the resin particle composition according to the present embodiment may be provided with a fixing member layer on at least a part of the surface of the water-absorbent resin particles.
  • the fixing member layer is preferably fixed to at least a part of the surface of the water-absorbent resin particles.
  • the resin particle composition according to the present embodiment can maintain high water absorption performance originally possessed by the water-absorbent resin particles while having an immobilization ability on a fibrous base material used for an absorber or the like.
  • the physiological saline water retention amount (hereinafter, may be simply referred to as “water retention amount”) according to the present embodiment is, for example, 30 g / g or more, 35 g / g or more, 38 g / g or more, or 40 g. It may be 50 g / g or less, 48 g / g or less, 45 g / g or less, or 43 g / g or less.
  • the amount of water-absorbent resin particles used in the resin particle composition according to the present embodiment is, for example, 33 g / g or more, 35 g / g or more, 38 g / g or more, 40 g / g or more, or 42 g / g. It may be 55 g / g or less, 52 g / g or less, 50 g / g or less, 48 g / g or less, 45 g / g or less, or 43 g / g or less.
  • the ratio of the water-retaining amount of the water-absorbent resin particles to the water-retaining amount of the resin particle composition according to the present embodiment is, for example, 60% or more. , 70% or more, 75% or more, 80% or more, or 85% or more, and may be 110% or less, 105% or less, 100% or less, 98% or less, 95% or less, or 90% or less. ..
  • the medium particle size of the resin particle composition according to the present embodiment may be, for example, 20 ⁇ m or more, 60 ⁇ m or more, 80 ⁇ m or more, 100 ⁇ m or more, 150 ⁇ m or more, 200 ⁇ m or more, or 250 ⁇ m or more, and 800 ⁇ m or less, 700 ⁇ m or less. It may be 600 ⁇ m or less, 500 ⁇ m or less, 450 ⁇ m or less, 400 ⁇ m or less, or 380 ⁇ m or less.
  • the fixing member layer preferably contains a heat-meltable resin.
  • the fixing member may be 80% by mass, 90% by mass or more, 95% by mass or more, 98% by mass or more, 99% by mass or more, or 100% by mass of a heat-meltable resin.
  • the glass transition temperature of the heat-meltable resin forming the fixing member layer may be, for example, 20 ° C. or higher, 25 ° C. or higher, 30 ° C. or higher, 35 ° C. or higher, 40 ° C. or higher, or 50 ° C. or higher, and 90 ° C. or lower.
  • the melting point of the heat-meltable resin forming the fixing member layer may be, for example, 70 to 175 ° C, 70 to 140 ° C, or 75 to 100 ° C.
  • the resin (that is, the fixing member) forming the fixing member layer examples include polyethylene, polypropylene, an ethylene / butene copolymer, an ethylene / propylene copolymer, and an ethylene-based polymer such as an ethylene-acrylic acid copolymer; polyethylene.
  • Polyether-based polymers such as glycol and polypropylene glycol; polyamide-based polymers such as nylon 6 and nylon 66; polyurethane-based polymers such as ether-based polyurethane, ester-based polyurethane and carbonate-based polyurethane; polyethylene terephthalate, polybutylene terephthalate and polyethylene.
  • Polyester polymers such as naphthalate and polybutylene naphthalate; polyacetals such as polyoxymethylene, polyacetaldehyde, polypropionaldehyde and polybutylaldehyde; polyvinyl fluoride; vinylidene fluoride; polysiloxane; and the like can be mentioned. These resins may be used alone or in combination of two or more.
  • Polyurethane is a reaction product of a polyol and a polyisocyanate.
  • the polyol include polyether polyols, polyester polyols, polybutadiene polyols, hydrogenated polybutadiene polyols, and the like.
  • polyisocyanate examples include aromatic isocyanates such as diphenylmethane diisocyanate, dimethyldiphenylmethane diisocyanate, tolylene diisocyanate, xylylene diisocyanate and p-phenylenedi isocyanate; alicyclic isocyanates such as dicyclohexylmethane diisocyanate and isophorone diisocyanate; hexamethylene diisocyanate and the like. Examples include aliphatic isocyanates.
  • the fixing member layer is chemically and / or physically bonded to the surface thereof so as not to easily fall off from the water-absorbent resin particles in the state before water absorption.
  • the physical bond is realized, for example, by the anchor effect generated by the fixing member layer entering the fine recesses existing on the surface of the water-absorbent resin particles.
  • the fixing member layer may be contained not only on the surface of the water-absorbent resin particles but also inside the water-absorbent resin particles. From the viewpoint of facilitating the manifestation of the effects of the present invention, it is preferable that most of the content of the fixing member layer is exposed and fixed in the vicinity of the surface.
  • the amount of the fixing member layer fixed in the vicinity of the surface may be 70% by mass or more or 90% by mass or more with respect to the total amount of the fixing member layer contained in the resin particle composition.
  • the heat-meltable resin of the fixing member layer may have a peeling adhesive strength of 1 to 500 N / 25 mm or 5 to 300 N / 25 mm as measured according to JIS Z0237.
  • the occupancy ratio (that is, coverage) of the fixing member layer to the surface area of the water-absorbent resin particles is 30% or more, 40% or more, 50% or more, 60% or more, 70% or more, 80% or more, 85% or more, 90. % Or more, 95% or more, 98% or more, or 99% or more, and may be 100% or less, 99% or less, 98% or less, 95% or less, 90% or less, or 80% or less.
  • the coverage is calculated by RAMAN touch (manufactured by Nanophoton).
  • the thickness of the fixing member layer of the resin particle composition may be 0.001 to 100 ⁇ m, 0.01 to 50 ⁇ m, or 0.1 to 30 ⁇ m.
  • the amount of the fixing member layer is 0.01 part by mass or more, 0.05 part by mass or more, 0.1 part by mass or more, and 0.5 part by mass with respect to 100 parts by mass of the water-absorbent resin particles. It may be 1 part by mass or more, 1.5 parts by mass or more, 2 parts by mass or more, 3 parts by mass or more, 4 parts by mass or more, or 5 parts by mass or more, and 10 parts by mass or less, 8 parts by mass or less, or It may be 6 parts by mass or less.
  • the water-absorbent resin particles may contain, for example, a crosslinked polymer formed by polymerizing a monomer containing an ethylenically unsaturated monomer.
  • the crosslinked polymer can have a monomeric unit derived from an ethylenically unsaturated monomer.
  • the water-absorbent resin particles can be produced, for example, by a method including a step of polymerizing a monomer containing an ethylenically unsaturated monomer. Examples of the polymerization method include a reverse phase suspension polymerization method, an aqueous solution polymerization method, a bulk polymerization method, a precipitation polymerization method and the like.
  • the ethylenically unsaturated monomer may be a water-soluble ethylenically unsaturated monomer.
  • water-soluble ethylenically unsaturated monomer include (meth) acrylic acid and its salt, 2- (meth) acrylamide-2-methylpropanesulfonic acid and its salt, (meth) acrylamide, N, N-dimethyl.
  • the ethylenically unsaturated monomer has an amino group, the amino group may be quaternized.
  • the ethylenically unsaturated monomer may be used alone or in combination of two or more.
  • the acid group may be neutralized with an alkaline neutralizing agent and then used in the polymerization reaction.
  • the degree of neutralization of the ethylenically unsaturated monomer by the alkaline neutralizing agent is, for example, 10 to 100 mol%, 50 to 90 mol%, or 60 to 80 mol% of the acidic group in the ethylenically unsaturated monomer. May be%.
  • the ethylenically unsaturated monomer is at least one selected from the group consisting of (meth) acrylic acid and salts thereof, acrylamide, methacrylamide, and N, N-dimethylacrylamide. It may contain a compound of the species.
  • the ethylenically unsaturated monomer may contain (meth) acrylic acid and a salt thereof, and at least one compound selected from the group consisting of acrylamide.
  • 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 may be 70 to 100 mol% with respect to the total amount of the monomers.
  • the ratio of (meth) acrylic acid and a salt thereof may be 70 to 100 mol% with respect to the total amount of the monomer.
  • Cross-linking may occur by self-cross-linking during polymerization, but cross-linking may be performed 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 (water retention amount, etc.) of the water-absorbent resin particles.
  • the internal cross-linking agent is usually added to the reaction solution during the polymerization reaction.
  • the water-absorbent resin particles may be crosslinked (surface crosslinked) in the vicinity of the surface. Further, the water-absorbent resin particles may be composed of only polymer particles (crosslinked polymers), but various types selected from, for example, gel stabilizers, metal chelating agents, fluidity improving agents (lubricants) and the like. It may further contain additional ingredients. Additional components may be placed inside the polymer particles, on the surface of the polymer particles, or both. The additional component may be a fluidity improver (lubricant).
  • the fluidity improver may contain inorganic particles. Examples of the inorganic particles include silica particles such as amorphous silica.
  • the shape of the water-absorbent resin particles may be, for example, substantially spherical, crushed or porous, and may be a shape in which primary particles having these shapes are aggregated. Above all, from the viewpoint of easy dispersion of the resin particles at the time of producing the absorber, a substantially spherical shape or an aggregated shape thereof is preferable.
  • the resin particle composition according to the present embodiment may include, for example, a step of mixing the water-absorbent resin particles and the fixing member to form a fixing member layer on at least a part of the surface of the water-absorbent resin particles.
  • the amount of the fixing member used for mixing is 0.1 part by mass or more, 0.5 part by mass or more, 1 part by mass or more, 2 parts by mass or more, or 3 parts by mass or more with respect to 100 parts by mass of the water-absorbent resin particles. It may be 10 parts by mass or less, 8 parts by mass or less, or 6 parts by mass or less.
  • the fixing member is, for example, a heat-meltable resin capable of forming the above-mentioned fixing member layer.
  • the resin usually contains a polymer composed of repeating units.
  • the fixing member may contain not only the heat-meltable polymer itself but also a forming material such as a monomer or a precursor thereof.
  • the fixing member layer contains polyurethane
  • the fixing member may contain polyurethane itself, or may contain a polyol and a polyisocyanate which are materials for forming the polyurethane.
  • the method for producing the resin particle composition according to the present embodiment is preferably after mixing the water-absorbent resin particles and the fixing member. It further comprises a step of polymerizing the members.
  • a specific method for producing the resin particle composition will be described for each state of the fixing member.
  • the fixing member can be fixed to the surface of the water-absorbent resin particles by using the particle composite device to form the fixing member layer. Specifically, a predetermined amount of water-absorbent resin particles and a solid (for example, powdery) fixing member are charged into the particle composite device. After that, stress (compressive stress and shear stress) is applied to the water-absorbent resin particles and the fixing member by the rotation of the stirring blade provided in the apparatus, and the fixing member is crimped to the surface of the water-absorbent resin particles by the stress.
  • a particle composition is prepared.
  • the thickness and coverage of the fixing member layer can be arbitrarily adjusted by appropriately adjusting the amounts of the water-absorbent resin particles and the fixing member to be charged into the particle composite device.
  • the water-absorbent resin particles and the fixing member may be separately charged into the particle composite device, but since more uniform dispersion and coating can be expected, the particles are in a state where the water-absorbent resin particles and the fixing member are mixed in advance. It is preferable to put it in the composite device.
  • the particle composite device it is easy to obtain a resin particle composition in which a fixing member layer is fixed to at least a part of the surface of the water-absorbent resin particles.
  • the particle compounding device for example, the particle compounding device Novirta MINI (manufactured by Sugino Machine Limited) can be used.
  • the liquid fixing member (hereinafter, simply referred to as "fixing member liquid”) can be obtained by melting the fixing member, or can be obtained by dissolving or dispersing the fixing member in an arbitrary solvent or dispersion medium. can. Since it is easy to form a fixing member layer having a uniform thickness, the fixing member liquid is preferably obtained by dissolving or dispersing the fixing member in an arbitrary solvent or dispersion medium. Whether the fixing member liquid becomes a solution or a dispersion liquid is determined by the properties of the fixing member and the medium used.
  • the solvent or dispersion medium examples include water, a hydrophilic compound, a mixture of water and a hydrophilic compound, a hydrocarbon compound, and the like.
  • the hydrophilic compound is a compound that dissolves substantially uniformly in water.
  • examples of the hydrophilic compound include alcohols such as methanol and isopropyl alcohol; glycols such as ethylene glycol; 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.
  • hydrocarbon compound examples include chain aliphatic hydrocarbons such as n-hexane, n-heptane, 2-methylhexane, 3-methylhexane, 2,3-dimethylpentane, 3-ethylpentane, and n-octane; Alicyclic 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, and the like. These may be used alone or in combination of two or more.
  • the concentration of the fixing member in the fixing member liquid is not particularly limited, and can be appropriately adjusted in consideration of the amount of water-absorbent resin particles in order to obtain a fixing member layer having a desired thickness. It may be 3 to 30% by mass, or 5 to 20% by mass.
  • the fixing member layer is, for example, (1) a method of adding the fixing member liquid to the hydrocarbon dispersion medium in which the water-absorbent resin particles are dispersed, and (2) the fixing member liquid and water absorption in the hydrocarbon dispersion medium.
  • a method of adding the sex resin particles substantially at the same time (3) a method of bringing the fixing member liquid into contact with the water-absorbent resin particles in a dry state, (4) a method of polymerizing the fixing member in the presence of the water-absorbent resin particles, or ( 5)
  • It can be formed by a method of cross-linking a fixing member (including a precursor) with a cross-linking agent in the presence of water-absorbent resin particles.
  • each method will be specifically described.
  • a separable flask equipped with a reflux condenser, a dropping funnel, a nitrogen gas introduction tube, and a stirrer is prepared.
  • the hydrocarbon dispersion medium and the water-absorbent resin particles are put into the flask, and the flask is sufficiently stirred while maintaining a high temperature (for example, 60 to 80 ° C.).
  • a solvent or a dispersion medium and a fixing member are added to the beaker and mixed to prepare a fixing member liquid.
  • the flask After adding the fixing member liquid into the flask and stirring sufficiently, the flask is immersed in an oil bath set at a high temperature (for example, 100 to 125 ° C.), and the hydrocarbon dispersion medium and water are co-distilled. While refluxing the hydrocarbon dispersion medium, water that may be contained in the reaction system is extracted from the system. Then, by evaporating the hydrocarbon dispersion medium, a resin particle composition in which the fixing member is fixed on the surface of the water-absorbent resin particles can be obtained.
  • a high temperature for example, 100 to 125 ° C.
  • the above method (3) is various, but the following are typical examples thereof: (3-1) a method using an eggplant flask, (3-2) a method using an atomizer, and (3-3) various granulators. The method using the above will be described.
  • the fixing member liquid is charged into the eggplant flask, and then the water-absorbent resin particles are charged.
  • the eggplant flask is attached to an evaporator and heated while rotating to distill off the solvent or dispersion medium contained in the fixing member liquid under reduced pressure conditions.
  • a resin particle composition in which the fixing member is fixed on the surface of the water-absorbent resin particles can be obtained.
  • (3-2) Water-absorbent resin particles are added to a separable flask equipped with a stirring blade and stirred.
  • the fixing member liquid is sprayed on the water-absorbent resin particles wound up by stirring with the stirring blade.
  • the fixing member liquid can be sprayed, for example, by using a two-fluid type nozzle. Since uniform dispersion and coating can be expected, it is desirable that the fixing member liquid is atomized and sprayed by an air flow of an inert gas such as nitrogen. Then, the contents of the flask are taken out, heated by a hot air dryer, and then cooled to room temperature to obtain a resin particle composition.
  • Examples of the granulator used for producing the resin particle composition include a rolling granulator, a stirring granulator, a fluidized bed granulator, and the like.
  • a shallow, inclined circular container provided in the rolling granulator is rotated, water-absorbent resin particles are supplied to the circular container, and an appropriate amount of fixing member liquid is added. Then, a part of the water-absorbent resin particles during rolling is aggregated by the solvent or the dispersion medium contained in the fixing member liquid, and the fixing member layer is formed on the surface thereof.
  • the step of adding the water-absorbent resin particles and the fixing member liquid may be performed a plurality of times if necessary.
  • the water-absorbent resin particles When using a stirring granulator, the water-absorbent resin particles are put into a mixer installed in the stirring granulator, mixed by stirring, and the fixing member liquid is added. Then, a part of the water-absorbent resin particles during stirring is aggregated by the solvent or the dispersion medium contained in the fixing member liquid, and the fixing member layer is formed on the surface thereof.
  • the step of adding the water-absorbent resin particles and the fixing member liquid may be performed a plurality of times if necessary. Excessive aggregation of the water-absorbent resin particles can be suppressed by controlling the shearing force of the mixer.
  • the water-absorbent resin particles are put into a container equipped in the fluidized bed granulator that can send out hot air from the lower part, and the water-absorbent resin particles are fluidized in advance.
  • the fixing member liquid is sprayed from the nozzle provided in the container, a part of the water-absorbent resin particles during stirring is aggregated by the solvent or the dispersion medium contained in the fixing member liquid, and the fixing member layer is formed on the surface thereof. It is formed.
  • the fixing member liquid may be sprayed multiple times if necessary. Excessive aggregation of the water-absorbent resin particles can be suppressed by adjusting the spraying amount and spraying frequency of the fixing member liquid.
  • a fluidized bed granulator FBD / SG manufactured by Mutual Co., Ltd.
  • gel-like water-absorbent resin particles containing water in a separable flask are prepared by a known reverse-phase suspension polymerization method.
  • the water-absorbent resin particles may be obtained by one-stage polymerization or may be obtained by two-stage or more multi-stage polymerization.
  • a monomer aqueous solution of the fixing member containing the fixing member, the polymerization initiator, and, if necessary, the internal cross-linking agent is prepared.
  • the fixing member contains, for example, a polyol and a polyisocyanate when the fixing member layer contains polyurethane.
  • gel-like water-absorbent resin particles containing water in a separable flask are prepared by a known reverse-phase suspension polymerization method.
  • the water-absorbent resin particles may be obtained by one-stage polymerization or may be obtained by two-stage or more multi-stage polymerization.
  • a precursor aqueous solution containing a fixing member (including a precursor) and a cross-linking agent is prepared.
  • the fixing member layer is formed using the fixing member liquid
  • the fixing member is likely to come into uniform contact with the water-absorbent resin particles, so that it is considered that the obtained resin particle composition is likely to exhibit prevention of falling off in the absorber.
  • the methods (1), (2), and (3) using the fluidized bed granulator, (4), and (5) have a more uniform thickness of the fixing member than the other methods. It is thought that the layer is easy to obtain.
  • the resin particle composition according to the present embodiment may be used in fields such as disposable diapers, sanitary materials such as sanitary products, agricultural and horticultural materials such as water retention agents and soil conditioners, and industrial materials such as water blocking agents and dew condensation inhibitors. Suitable.
  • Example 1 Preparation of water-absorbent resin particles
  • 293 g of n-heptane was added as a hydrocarbon dispersion medium, and 0.736 g of a maleic anhydride-modified ethylene-propylene copolymer (Mitsui Chemicals, Inc., High Wax 1105A) was added as a polymer-based dispersant.
  • the mixture in the flask was heated to 80 ° C. with stirring to dissolve the dispersant, and then cooled to 50 ° C.
  • hydroxyethyl cellulose (Sumitomo Seika Co., Ltd., HEC AW-15F) as a thickener
  • 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.
  • 0.010 g (0.057 mmol) of glycol diglycidyl ether was added and dissolved to prepare a first-stage monomer aqueous solution.
  • the inside of the flask system was cooled to 25 ° C. while stirring at a stirring speed of 1000 rpm, and then the entire amount of the second-stage monomer aqueous solution was added to the first-stage polymerized slurry liquid to add the system.
  • the inside was replaced with nitrogen for 30 minutes.
  • the flask was immersed in a water bath at 70 ° C. again to raise the temperature, and the polymerization reaction was carried out for 60 minutes to obtain a hydrogel-like polymer.
  • hydrogel polymer 0.589 g of a 45% by mass diethylenetriamine-5 sodium acetate aqueous solution was added under stirring. Then, the flask was immersed in an oil bath set at 125 ° C., and 257.2 g of water was extracted from the system while refluxing n-heptane by azeotropic distillation of n-heptane and water. Then, 4.42 g (0.507 mmol) of a 2% by mass ethylene glycol diglycidyl ether aqueous solution was added to the flask as a surface cross-linking agent, and the mixture was kept at 83 ° C. for 2 hours.
  • n-heptane and water were heated in an oil bath at 125 ° C. to evaporate and dried to obtain a dried product of polymer particles.
  • the polymer particles were passed through a sieve having an opening of 850 ⁇ m to obtain 231.2 g of water-absorbent resin particles.
  • the above operation was repeated, and the obtained water-absorbent resin particles were classified by a sieve having an opening of 250 ⁇ m, and 500 g or more of the water-absorbent resin particles (A) having a particle diameter of 250 to 850 ⁇ m were obtained.
  • the water retention amount of the water-absorbent resin particles (A) was 41 g / g.
  • Example 2 Same as Example 1 except that the fixing member liquid was changed to a solution obtained by diluting 57.1 g of a 35% aqueous dispersion emulsion of polyurethane (Daiichi Kogyo Seiyaku Co., Ltd., Superflex 210) with 342.9 g of ion-exchanged water. To obtain 508.1 g of a resin particle composition having a medium particle diameter of 345 ⁇ m.
  • Example 3 Example 1 and the fixing member liquid were changed to those obtained by diluting 62.5 g of a 40% aqueous dispersion emulsion of a nylon copolymer (Sumitomo Seika Co., Ltd., Sepoljon PA200) with 187.5 g of ion-exchanged water. The same procedure was carried out to obtain 502.3 g of a resin particle composition having a medium particle diameter of 336 ⁇ m.
  • Example 4 The fixing member liquid was changed to one obtained by dissolving 20.0 g of polyethylene glycol (Fujifilm Wako Pure Chemical Industries, Ltd., polyethylene glycol 6,000) in 180.0 g of ion-exchanged water, and warm air in a fluidized bed granulator. The same procedure as in Example 1 was carried out except that the temperature and the drying temperature were changed to 60 ° C. to obtain 508.3 g of a resin particle composition having a medium particle diameter of 347 ⁇ m.
  • polyethylene glycol Flujifilm Wako Pure Chemical Industries, Ltd., polyethylene glycol 6,000
  • Example 5 The fixing member liquid was changed to one in which 25.0 g of an ethylene-sodium acrylate copolymer (SK particle chemical, primacol) was dissolved in 225.0 g of tetrahydrofuran, and the temperature and drying of hot air in a fluidized bed granulator. The same procedure as in Example 1 was carried out except that the temperature was changed to 40 ° C. to obtain 502.0 g of a resin particle composition having a medium particle diameter of 337 ⁇ m.
  • SK particle chemical, primacol ethylene-sodium acrylate copolymer
  • a 2 L volume, round-bottomed cylindrical separable flask with four side wall baffles (baffle length: 10 cm, baffle width: 7 mm) was prepared.
  • the mixture in the flask was heated to 50 ° C. while stirring at a rotation speed of 300 rpm to dissolve the surfactant, and then cooled to 40 ° C.
  • the polymer solution containing the produced hydrogel-like polymer, n-heptane and a surfactant was mixed for 10 minutes while stirring at a stirring speed of 1000 rpm.
  • the flask containing the reaction solution was immersed in an oil bath at 125 ° C., and 97.0 g of water was extracted from the system while refluxing n-heptane by azeotropic distillation of n-heptane and water.
  • sorbitan monolaurate (trade name: Nonion LP-20R, HLB value 8.6, manufactured by Nichiyu Co., Ltd.), which is a surfactant, in 6.62 g of n-heptane. did.
  • the surfactant solution was added into the flask.
  • the water-absorbing resin particles (B) had a water retention amount of 38 g / g and a medium particle diameter of 205 ⁇ m.
  • the fixing member liquid was changed to 100.0 g of a 25% aqueous dispersion emulsion of an ethylene-sodium acrylate copolymer (Sumitomo Seika Co., Ltd., Zyxen N) diluted with 150.0 g of ion-exchanged water.
  • the same operation as in Example 1 was carried out except that the water-absorbent resin particles (B) were used instead of the water-absorbent resin particles (A), and 506.3 g of a resin particle composition having a medium particle diameter of 213 ⁇ m was obtained. ..
  • Example 7 (Preparation of water-absorbent resin particles)
  • 293 g of n-heptane was added as a hydrocarbon dispersion medium, and 0.736 g of a maleic anhydride-modified ethylene-propylene copolymer (Mitsui Chemicals, Inc., High Wax 1105A) was added as a polymer-based dispersant.
  • the mixture in the flask was heated to 80 ° C. with stirring to dissolve the dispersant, and then cooled to 50 ° C.
  • hydroxyethyl cellulose (Sumitomo Seika Co., Ltd., HEC AW-15F) as a thickener
  • 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.
  • 0.010 g (0.057 mmol) of glycol diglycidyl ether was added and dissolved to prepare a first-stage monomer aqueous solution.
  • a surfactant solution was prepared by heating and dissolving 0.736 g of sucrose stearic acid ester (HLB: 3, Mitsubishi Chemical Foods Co., Ltd., Ryoto Sugar Ester S-370) as a surfactant in 6.62 g of n-heptane. ..
  • HLB sucrose stearic acid ester
  • the surfactant solution is added to the flask, and the inside of the system is stirred while stirring at a stirring speed of 500 rpm. Was sufficiently replaced with.
  • the flask was immersed in a water bath at 70 ° C. to raise the temperature, and the polymerization was carried out for 60 minutes to obtain a first-stage polymerization slurry liquid.
  • the inside of the flask system was cooled to 44 ° C. while stirring at a stirring machine rotation speed of 1000 rpm. Then, the whole amount of the aqueous solution of the second stage was added to the polymerized slurry solution of the first stage, and the inside of the system was replaced with nitrogen for 30 minutes. Then, the flask was immersed in a water bath at 70 ° C. again to raise the temperature, and the polymerization reaction was carried out for 60 minutes to obtain a hydrogel polymer.
  • the flask was immersed in an oil bath set at 125 ° C., and 260.1 g of water was extracted from the system while refluxing n-heptane by azeotropic distillation of n-heptane and water. Then, 4.42 g (0.507 mmol) of a 2% by mass ethylene glycol diglycidyl ether aqueous solution was added to the flask as a surface cross-linking agent, and the mixture was kept at 83 ° C. for 2 hours.
  • the water-absorbing resin particles (C) had a water retention amount of 43 g / g and a medium particle diameter of 72 ⁇ m.
  • the fixing member liquid was changed to 100.0 g of a 25% aqueous dispersion emulsion of an ethylene-sodium acrylate copolymer (Sumitomo Seika Co., Ltd., Zyxen N) diluted with 150.0 g of ion-exchanged water.
  • the same procedure as in Example 1 was carried out except that the water-absorbent resin particles (C) were used instead of the water-absorbent resin particles (A), and 504.8 g of a resin particle composition having a medium particle diameter of 86 ⁇ m was obtained.
  • the obtained resin particle composition was evaluated according to the following items. Unless otherwise specified, the measurements were carried out in an environment with a temperature of 25 ⁇ 2 ° C. and a humidity of 50 ⁇ 10%.
  • a release paper (KA-4G white BD manufactured by Lintec Corporation) coated with silicone on one side was cut into a circle having a diameter of 50 mm.
  • a circular release paper was laid in a circular stainless steel petri dish with an inner diameter of 52 mm so that the silicone-coated surface was on top.
  • 2.0 ⁇ 0.002 g of a resin particle composition excluding particles having a particle size of 850 ⁇ m or more was uniformly sprinkled on the release paper.
  • a release paper similar to the above is placed on the resin particle composition so that the silicone-coated surface is in contact with the resin particle composition, and a circular stainless steel canyon having an outer diameter of 50 mm and a mass of 20 g and a columnar diameter of 45 mm are placed.
  • a measurement sample was prepared by stacking 780 g of the weights in this order.
  • the measurement sample was placed in a hot air dryer set to an internal temperature of 80 ° C. and allowed to stand for 1 hour.
  • the measurement sample was taken out from the hot air dryer and allowed to cool to room temperature.
  • the resin particle composition is taken out from the measurement sample together with the release paper, and the resin particle composition is carefully removed from the release paper on a sieve (inner diameter 200 mm) having an opening of 850 ⁇ m with a saucer at the bottom, and the total amount of the resin particle composition is obtained.
  • a sieve inner diameter 200 mm
  • the water retention amount of the water-absorbent resin particles and the physiological saline of the resin particle composition was measured by the following procedure. First, a cotton bag (Membrod No. 60, width 100 mm ⁇ length 200 mm) from which 2.0 ⁇ 0.002 g of measurement particles were weighed was placed in a beaker having an internal volume of 500 mL. After pouring 500 g of physiological saline into a cotton bag containing the measurement particles at a time so that maco could not be formed, the upper part of the cotton bag was tied with a rubber band and allowed to stand for 30 minutes to swell the measurement particles.
  • the cotton bag after 30 minutes was dehydrated for 1 minute using a dehydrator (manufactured by Kokusan Co., Ltd., product number: H-122) set to have a centrifugal force of 167 G, and then contained the swollen gel after dehydration.
  • the mass Wc [g] of the cotton bag was measured. Perform the same operation without adding the water-absorbent resin particles or the resin particle composition, measure the empty mass Wd [g] when the cotton bag is wet, and use the following formula to measure the physiology of the water-absorbent resin particles and the resin particle composition.
  • the above-mentioned medium particle size of the resin particle composition was measured by the following procedure. That is, from the top of the JIS standard sieve, a sieve with an opening of 600 ⁇ m, a sieve with an opening of 500 ⁇ m, a sieve with an opening of 425 ⁇ m, a sieve with an opening of 300 ⁇ m, a sieve with an opening of 250 ⁇ m, a sieve with an opening of 180 ⁇ m, and a sieve with an opening of 150 ⁇ m. , And the saucer in that order. 50 g of the resin particle composition was put into the combined best sieve and shaken for 10 minutes using a low-tap type shaker to classify.
  • the mass of the particles remaining on each sieve was calculated as a mass percentage with respect to the total amount, and the particle size distribution was obtained.
  • the relationship between the mesh size of the sieve and the integrated value of the mass percentage of the particles remaining on the sieve was plotted on a logarithmic probability paper by integrating the particles on the sieve in order from the one having the largest particle size with respect to this particle size distribution. By connecting the plots on the probability paper with a straight line, the particle size corresponding to the integrated mass percentage of 50% by mass was obtained as the medium particle size.
  • a resin particle composition having a caking index of a certain level or higher was obtained.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Health & Medical Sciences (AREA)
  • Medicinal Chemistry (AREA)
  • Polymers & Plastics (AREA)
  • Analytical Chemistry (AREA)
  • Dispersion Chemistry (AREA)
  • Solid-Sorbent Or Filter-Aiding Compositions (AREA)
  • Absorbent Articles And Supports Therefor (AREA)

Abstract

This resin particle composition has water-absorbing resin particles and a fixing member layer, and is configured such that, when a caking test is performed in the order of (1) through (5), at least a portion of the particles remain on a sieve used, the sieve having an aperture of 850 μm.

Description

樹脂粒子組成物Resin particle composition
　本発明は、樹脂粒子組成物に関する。 The present invention relates to a resin particle composition.
　樹脂粒子のなかでも、生活における必須要素である水を吸収して保持する特性を有する吸水性樹脂粒子は、紙おむつ、生理用品等の衛生材料、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分野で広く用いられている。吸水性樹脂粒子は通常、接着力がない粉末であるため、上記用途では、不織布等の繊維質基材上に吸水性樹脂粒子を散布してサンドイッチ状に形成した吸収体として用いている。このとき、吸水性樹脂粒子を基材に固定させるために、接着剤を塗布した繊維質基材上に吸水性樹脂粒子を散布する方法が行われている（例えば特許文献１）。 Among the resin particles, the water-absorbent resin particles having the property of absorbing and retaining water, which is an essential element in daily life, are sanitary materials such as paper diapers and sanitary products, agricultural and horticultural materials such as water retention agents and soil improvers, and stoppers. It is widely used in fields such as industrial materials such as water agents and anti-condensation agents. Since the water-absorbent resin particles are usually powders having no adhesive force, they are used as an absorber formed in a sandwich shape by spraying the water-absorbent resin particles on a fibrous base material such as a non-woven fabric in the above application. At this time, in order to fix the water-absorbent resin particles to the base material, a method of spraying the water-absorbent resin particles on the fibrous base material coated with the adhesive is performed (for example, Patent Document 1).
国際出願第２０１１／０４３２５６号International Application No. 2011/043256
　接着剤により繊維質基材に吸水性樹脂粒子を固着させる方法では、基材に塗布された接着剤に接している吸水性樹脂粒子のみが固着され、それ以外の粒子は固着されず吸収体内で遊離している。そのため、吸収体製造工程及び運搬時に吸収体の端から脱落することがある。 In the method of fixing the water-absorbent resin particles to the fibrous base material with an adhesive, only the water-absorbent resin particles in contact with the adhesive applied to the base material are fixed, and the other particles are not fixed and are not fixed in the absorbent body. It is free. Therefore, it may fall off from the end of the absorber during the absorber manufacturing process and transportation.
　本発明は、吸収体から脱落しにくい樹脂粒子組成物を提供することを目的とする。 An object of the present invention is to provide a resin particle composition that does not easily fall off from an absorber.
　本発明の樹脂粒子組成物は、吸水性樹脂粒子と定着部材層とを有し、下記（１）～（５）の順に行われるケーキング試験後に、用いた目開き８５０μｍの篩上に粒子の少なくとも一部が残存する。
（１）内径５２ｍｍの円形ステンレス製シャーレの底に、直径５０ｍｍの円形剥離紙を敷き、該剥離紙の上に、粒径８５０μｍ未満の樹脂粒子組成物２．０ｇを散布する。
（２）散布した樹脂粒子組成物の上に、直径５０ｍｍの円形剥離紙、外形５０ｍｍで質量２０ｇの円形ステンレス製シャーレ、及び直径４５ｍｍの円柱状重り７８０ｇをこの順に重ねることにより測定サンプルを得る。
（３）測定サンプルを熱風乾燥機により８０℃で１時間乾燥させた後、室温まで放冷する。
（４）放冷後の該剥離紙から樹脂粒子組成物を取り外して回収し、回収した樹脂粒子組成物の全量を目開き８５０μｍの篩上に載せる。
（５）上記篩をロータップ式篩振盪機にて５秒間振盪した後に篩上に樹脂粒子組成物が残存するかを確認する。 The resin particle composition of the present invention has water-absorbent resin particles and a fixing member layer, and after the caking test performed in the order of (1) to (5) below, at least the particles are placed on a sieve having an opening of 850 μm. Some remain.
(1) A circular release paper having a diameter of 50 mm is laid on the bottom of a circular stainless steel petri dish having an inner diameter of 52 mm, and 2.0 g of a resin particle composition having a particle size of less than 850 μm is sprayed on the release paper.
(2) A measurement sample is obtained by stacking a circular release paper having a diameter of 50 mm, a circular stainless steel petri dish having an outer diameter of 50 mm and a mass of 20 g, and a cylindrical weight having a diameter of 45 mm, 780 g, on the sprayed resin particle composition in this order.
(3) The measurement sample is dried at 80 ° C. for 1 hour with a hot air dryer, and then allowed to cool to room temperature.
(4) The resin particle composition is removed from the release paper after cooling and recovered, and the entire amount of the recovered resin particle composition is placed on a sieve having an opening of 850 μm.
(5) After shaking the above sieve with a low-tap type sieve shaker for 5 seconds, it is confirmed whether the resin particle composition remains on the sieve.
　上記樹脂粒子組成物は、上記ケーキング試験により測定される、下記式で示されるケーキング指数が２０％以上であることが好ましい。
　ケーキング指数（％）＝［目開き８５０μｍの篩上に残存した樹脂粒子組成物の質量／（目開き８５０μｍの篩上に残存した樹脂粒子組成物及び目開き８５０μｍの篩を通過した樹脂粒子組成物の合計質量）］×１００ The resin particle composition preferably has a caking index of 20% or more, which is measured by the caking test and is represented by the following formula.
Caking index (%) = [Mass of resin particle composition remaining on a sieve with an opening of 850 μm / (Resin particle composition remaining on a sieve with an opening of 850 μm and a resin particle composition passing through a sieve with an opening of 850 μm) Total mass)] x 100
　上記定着部材層は、エチレン系重合体、ポリエーテル系重合体、ポリアミド系重合体、ポリウレタン系重合体、及びポリエステル系重合体からなる群から選ばれる少なくとも１種を含んでよい。 The fixing member layer may contain at least one selected from the group consisting of an ethylene-based polymer, a polyether-based polymer, a polyamide-based polymer, a polyurethane-based polymer, and a polyester-based polymer.
　上記定着部材の量は、吸水性樹脂粒子１００質量部に対して、０．０１～１０質量部であってよい。 The amount of the fixing member may be 0.01 to 10 parts by mass with respect to 100 parts by mass of the water-absorbent resin particles.
　上記樹脂粒子組成物は、生理食塩水保水量が３０ｇ／ｇ以上であってよい。 The resin particle composition may have a physiological saline water retention amount of 30 g / g or more.
　本発明により、吸収体から脱落しにくい樹脂粒子組成物が提供される。 The present invention provides a resin particle composition that does not easily fall off from the absorber.
　以下、本発明のいくつかの実施形態について詳細に説明する。ただし、本発明は以下の実施形態に限定されるものではない。 Hereinafter, some embodiments of the present invention will be described in detail. However, the present invention is not limited to the following embodiments.
　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、実施例に示されている値に置き換えてもよい。本明細書に例示する材料は、単独で用いられてもよく、２種以上を組み合わせて用いられてもよい。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。「水溶性」とは、２５℃において水に５質量％以上の溶解性を示すことをいう。「室温」とは、２５±２℃をいう。「層」との語は、平面図として観察したときに、全面に形成されている形状の構造に加え、一部に形成されている形状の構造も包含される。 In this specification, "acrylic" and "methacrylic" are collectively referred to as "(meth) acrylic". Similarly, "acrylate" and "methacrylate" are also referred to as "(meth) acrylate". "(Poly)" shall mean both with and without the "poly" prefix. Within the numerical range described stepwise herein, the upper or lower limit of the numerical range at one stage may be optionally combined with the upper or lower limit of the numerical range at another stage. In the numerical range described in the present specification, the upper limit value or the lower limit value of the numerical range may be replaced with the value shown in the examples. The materials exemplified in the present specification may be used alone or in combination of two or more. The content of 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. "Water-soluble" means that it exhibits a solubility in water of 5% by mass or more at 25 ° C. "Room temperature" means 25 ± 2 ° C. The term "layer" includes not only a structure having a shape formed on the entire surface but also a structure having a shape partially formed when observed as a plan view.
　本実施形態に係る樹脂粒子組成物は、吸水性樹脂粒子と、定着部材層とを有する。樹脂粒子組成物は、下記（１）～（５）の順に行われるケーキング試験において測定されるケーキング性を有する。ケーキング性を有するとは、下記のケーキング試験の（５）の工程の後に、用いた目開き８５０μｍの篩上に粒子の少なくとも一部が残存することをいう。
（１）内径５２ｍｍの円形ステンレス製シャーレの底に、直径５０ｍｍの円形剥離紙を敷き、該剥離紙の上に、粒径８５０μｍ未満の樹脂粒子組成物２．０ｇを散布する。
（２）散布した樹脂粒子組成物の上に、直径５０ｍｍの円形剥離紙、外形５０ｍｍで質量２０ｇの円形ステンレス製シャーレ、及び直径４５ｍｍの円柱状重り７８０ｇをこの順に重ねることにより測定サンプルを得る。これにより樹脂粒子組成物に４０００Ｐａの加圧がなされる。
（３）測定サンプルを熱風乾燥機により８０℃で１時間乾燥させた後、室温まで放冷する。
（４）放冷後の該剥離紙から樹脂粒子組成物を取り外して回収し、回収した樹脂粒子組成物の全量を目開き８５０μｍの篩上に載せる。
（５）上記篩をロータップ式篩振盪機にて５秒間振盪した後に篩上に樹脂粒子組成物が残存するかを確認する。 The resin particle composition according to the present embodiment has water-absorbent resin particles and a fixing member layer. The resin particle composition has a caking property measured in the caking test performed in the order of (1) to (5) below. Having a caking property means that at least a part of the particles remains on the sieve having an opening of 850 μm used after the step (5) of the caking test below.
(1) A circular release paper having a diameter of 50 mm is laid on the bottom of a circular stainless steel petri dish having an inner diameter of 52 mm, and 2.0 g of a resin particle composition having a particle size of less than 850 μm is sprayed on the release paper.
(2) A measurement sample is obtained by stacking a circular release paper having a diameter of 50 mm, a circular stainless steel petri dish having an outer diameter of 50 mm and a mass of 20 g, and a cylindrical weight having a diameter of 45 mm, 780 g, on the sprayed resin particle composition in this order. As a result, the resin particle composition is pressurized at 4000 Pa.
(3) The measurement sample is dried at 80 ° C. for 1 hour with a hot air dryer, and then allowed to cool to room temperature.
(4) The resin particle composition is removed from the release paper after cooling and recovered, and the entire amount of the recovered resin particle composition is placed on a sieve having an opening of 850 μm.
(5) After shaking the above sieve with a low-tap type sieve shaker for 5 seconds, it is confirmed whether the resin particle composition remains on the sieve.
　本実施形態に係る樹脂粒子組成物は、上記ケーキング試験で測定されるケーキング性を有するため、例えば吸収体作製の際に、樹脂粒子組成物と繊維質基材とを重ねて加圧加熱することにより、別途接着剤を用いなくても、繊維質基材に樹脂粒子組成物を固定化することが可能である。上記ケーキング試験は、直接的には樹脂粒子組成物同士の結着性の指標であるが、このようなケーキング性を有する樹脂粒子組成物は、繊維質基材に対しても加圧加熱により結着することが可能である。 Since the resin particle composition according to the present embodiment has the caking property measured in the caking test, for example, when the absorber is produced, the resin particle composition and the fibrous base material are overlapped and heated under pressure. Therefore, it is possible to immobilize the resin particle composition on the fibrous base material without using a separate adhesive. The above caking test is a direct index of the binding property between the resin particle compositions, but the resin particle composition having such caking property is also bonded to the fibrous substrate by pressure heating. It is possible to wear it.
　本実施形態に係る樹脂粒子組成物は、下記式で示されるケーキング指数が２０％以上であることが好ましい。ケーキング指数は、上記ケーキング試験の（５）の工程後に、目開き８５０μｍの篩上に残存した樹脂粒子組成物の質量、及び目開き８５０μｍの篩を通過した樹脂粒子組成物の質量を測定することにより算出することができる。
　ケーキング指数（％）＝［目開き８５０μｍの篩上に残存した樹脂粒子組成物の質量／（目開き８５０μｍの篩上に残存した樹脂粒子組成物及び目開き８５０μｍの篩を通過した樹脂粒子組成物の合計質量）］×１００ The resin particle composition according to the present embodiment preferably has a caking index of 20% or more represented by the following formula. The caking index is measured by measuring the mass of the resin particle composition remaining on the sieve having an opening of 850 μm and the mass of the resin particle composition passing through the sieve having an opening of 850 μm after the step (5) of the caking test. Can be calculated by
Caking index (%) = [Mass of resin particle composition remaining on a sieve with an opening of 850 μm / (Resin particle composition remaining on a sieve with an opening of 850 μm and a resin particle composition passing through a sieve with an opening of 850 μm) Total mass)] x 100
　本実施形態に係る樹脂粒子組成物のケーキング指数は、２０％以上、２５％以上、３０％以上、３５％以上、４０％以上、４５％以上、５０％以上、５５％以上、６０％以上、６５％以上、７０％以上、７５％以上、７８％以上、８０％以上、８５％以上、９０％以上、又は９５％以上であってよい。本実施形態に係る樹脂粒子組成物のケーキング指数は、１００％以下、９９％以下、９８％以下、９７％以下、又は９５％以下であってよい。 The caking index of the resin particle composition according to the present embodiment is 20% or more, 25% or more, 30% or more, 35% or more, 40% or more, 45% or more, 50% or more, 55% or more, 60% or more, It may be 65% or more, 70% or more, 75% or more, 78% or more, 80% or more, 85% or more, 90% or more, or 95% or more. The caking index of the resin particle composition according to the present embodiment may be 100% or less, 99% or less, 98% or less, 97% or less, or 95% or less.
　本実施形態に係る樹脂粒子組成物は、吸水性樹脂粒子と定着部材層とを有している。本実施形態に係る樹脂粒子組成物は、吸水性樹脂粒子の表面の少なくとも一部に定着部材層が設けられていてよい。定着部材層は、吸水性樹脂粒子の表面の少なくとも一部に固定されていることが好ましい。 The resin particle composition according to the present embodiment has water-absorbent resin particles and a fixing member layer. The resin particle composition according to the present embodiment may be provided with a fixing member layer on at least a part of the surface of the water-absorbent resin particles. The fixing member layer is preferably fixed to at least a part of the surface of the water-absorbent resin particles.
　本実施形態に係る樹脂粒子組成物は、吸収体等に用いられる繊維質基材への固定化能を有しながらも、吸水性樹脂粒子が本来有する吸水性能を高く維持することができる。 The resin particle composition according to the present embodiment can maintain high water absorption performance originally possessed by the water-absorbent resin particles while having an immobilization ability on a fibrous base material used for an absorber or the like.
　本実施形態に係る樹脂粒子組成物の生理食塩水保水量（以下、単に「保水量」という場合もある。）は、例えば、３０ｇ／ｇ以上、３５ｇ／ｇ以上、３８ｇ／ｇ以上、又は４０ｇ／ｇ以上であってよく、５０ｇ／ｇ以下、４８ｇ／ｇ以下、４５ｇ／ｇ以下、又は４３ｇ／ｇ以下であってよい。 The physiological saline water retention amount (hereinafter, may be simply referred to as “water retention amount”) according to the present embodiment is, for example, 30 g / g or more, 35 g / g or more, 38 g / g or more, or 40 g. It may be 50 g / g or less, 48 g / g or less, 45 g / g or less, or 43 g / g or less.
　本実施形態に係る樹脂粒子組成物に用いられる吸水性樹脂粒子の生理食塩水保水量は、例えば、３３ｇ／ｇ以上、３５ｇ／ｇ以上、３８ｇ／ｇ以上、４０ｇ／ｇ以上、又は４２ｇ／ｇ以上であってよく、５５ｇ／ｇ以下、５２ｇ／ｇ以下、５０ｇ／ｇ以下、４８ｇ／ｇ以下、４５ｇ／ｇ以下、又は４３ｇ／ｇ以下であってよい。 The amount of water-absorbent resin particles used in the resin particle composition according to the present embodiment is, for example, 33 g / g or more, 35 g / g or more, 38 g / g or more, 40 g / g or more, or 42 g / g. It may be 55 g / g or less, 52 g / g or less, 50 g / g or less, 48 g / g or less, 45 g / g or less, or 43 g / g or less.
　本実施形態に係る樹脂粒子組成物の保水量に対する吸水性樹脂粒子の保水量の比率（すなわち、樹脂粒子組成物の保水量÷吸水性樹脂粒子の保水量×１００）は、例えば、６０％以上、７０％以上、７５％以上、８０％以上、又は８５％以上であってよく、１１０％以下、１０５％以下、１００％以下、９８％以下、９５％以下、又は９０％以下であってよい。 The ratio of the water-retaining amount of the water-absorbent resin particles to the water-retaining amount of the resin particle composition according to the present embodiment (that is, the water-retaining amount of the resin particle composition ÷ the water-retaining amount of the water-absorbent resin particles × 100) is, for example, 60% or more. , 70% or more, 75% or more, 80% or more, or 85% or more, and may be 110% or less, 105% or less, 100% or less, 98% or less, 95% or less, or 90% or less. ..
　本実施形態に係る樹脂粒子組成物の中位粒子径は、例えば、２０μｍ以上、６０μｍ以上、８０μｍ以上、１００μｍ以上、１５０μｍ以上、２００μｍ以上、又は２５０μｍ以上であってよく、８００μｍ以下、７００μｍ以下、６００μｍ以下、５００μｍ以下、４５０μｍ以下、４００μｍ以下、又は３８０μｍ以下であってよい。 The medium particle size of the resin particle composition according to the present embodiment may be, for example, 20 μm or more, 60 μm or more, 80 μm or more, 100 μm or more, 150 μm or more, 200 μm or more, or 250 μm or more, and 800 μm or less, 700 μm or less. It may be 600 μm or less, 500 μm or less, 450 μm or less, 400 μm or less, or 380 μm or less.
［定着部材層］
　定着部材層は、熱溶融性樹脂を含むことが好ましい。定着部材は、その８０質量％、９０質量％以上、９５質量％以上、９８質量％以上、９９質量％以上、又は１００質量％が熱溶融性樹脂であってよい。定着部材層を形成する熱溶融性樹脂のガラス転移温度は、例えば、２０℃以上、２５℃以上、３０℃以上、３５℃以上、４０℃以上、又は５０℃以上であってよく、９０℃以下、８０℃以下、７５℃以下、７０℃以下、６５℃以下、６０℃以下、５５℃以下、又は５０℃以下であってよい。定着部材層を形成する熱溶融性樹脂の融点は、例えば、７０～１７５℃、７０～１４０℃、又は７５～１００℃であってよい。 [Fixing member layer]
The fixing member layer preferably contains a heat-meltable resin. The fixing member may be 80% by mass, 90% by mass or more, 95% by mass or more, 98% by mass or more, 99% by mass or more, or 100% by mass of a heat-meltable resin. The glass transition temperature of the heat-meltable resin forming the fixing member layer may be, for example, 20 ° C. or higher, 25 ° C. or higher, 30 ° C. or higher, 35 ° C. or higher, 40 ° C. or higher, or 50 ° C. or higher, and 90 ° C. or lower. , 80 ° C or lower, 75 ° C or lower, 70 ° C or lower, 65 ° C or lower, 60 ° C or lower, 55 ° C or lower, or 50 ° C or lower. The melting point of the heat-meltable resin forming the fixing member layer may be, for example, 70 to 175 ° C, 70 to 140 ° C, or 75 to 100 ° C.
　定着部材層を形成する樹脂（すなわち定着部材）としては、例えば、ポリエチレン、ポリプロピレン、エチレン・ブテン共重合体、エチレン・プロピレン共重合体、エチレン－アクリル酸共重合体等のエチレン系重合体；ポリエチレングリコール、ポリプロピレングリコール等のポリエーテル系重合体；ナイロン６、ナイロン６６等のポリアミド系重合体；エーテル系ポリウレタン、エステル系ポリウレタン、カーボネート系ポリウレタン等のポリウレタン系重合体；ポリエチレンテレフタレート、ポリブチレンテレフタレート、ポリエチレンナフタレート、ポリブチレンナフタレート等のポリエステル系重合体；ポリオキシメチレン、ポリアセトアルデヒド、ポリプロピオンアルデヒド、ポリブチルアルデヒド等のポリアセタール；ポリフッ化ビニル；ポリフッ化ビニリデン；ポリシロキサン；などが挙げられる。これらの樹脂は、単独で用いてもよく、複数種を組み合わせて用いてもよい。 Examples of the resin (that is, the fixing member) forming the fixing member layer include polyethylene, polypropylene, an ethylene / butene copolymer, an ethylene / propylene copolymer, and an ethylene-based polymer such as an ethylene-acrylic acid copolymer; polyethylene. Polyether-based polymers such as glycol and polypropylene glycol; polyamide-based polymers such as nylon 6 and nylon 66; polyurethane-based polymers such as ether-based polyurethane, ester-based polyurethane and carbonate-based polyurethane; polyethylene terephthalate, polybutylene terephthalate and polyethylene. Polyester polymers such as naphthalate and polybutylene naphthalate; polyacetals such as polyoxymethylene, polyacetaldehyde, polypropionaldehyde and polybutylaldehyde; polyvinyl fluoride; vinylidene fluoride; polysiloxane; and the like can be mentioned. These resins may be used alone or in combination of two or more.
　なお、ポリウレタンは、ポリオールとポリイソシアネートとの反応物である。ポリオールとしては、例えば、ポリエーテルポリオール、ポリエステルポリオール、ポリブタジエンポリール、水素化ポリブタジエンポリオール等が挙げられる。ポリイソシアネートとしては、例えば、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、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、イソホロンジイソシアネート等の脂環族イソシアネート；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が挙げられる。 Polyurethane is a reaction product of a polyol and a polyisocyanate. Examples of the polyol include polyether polyols, polyester polyols, polybutadiene polyols, hydrogenated polybutadiene polyols, and the like. Examples of the polyisocyanate include aromatic isocyanates such as diphenylmethane diisocyanate, dimethyldiphenylmethane diisocyanate, tolylene diisocyanate, xylylene diisocyanate and p-phenylenedi isocyanate; alicyclic isocyanates such as dicyclohexylmethane diisocyanate and isophorone diisocyanate; hexamethylene diisocyanate and the like. Examples include aliphatic isocyanates.
　定着部材層は、吸水前の状態にある吸水性樹脂粒子から容易に脱落しないよう、その表面に化学的及び／又は物理的に結合していることが好ましい。なお、物理的な結合は、例えば、吸水性樹脂粒子の表面に存在する微細凹部に定着部材層が入り込むことによって生じるアンカー効果によって実現される。定着部材層は、吸水性樹脂粒子の表面だけでなく、吸水性樹脂粒子の内部に含まれていてもよい。本発明の効果を発現しやすくする観点から、定着部材層は、その含有量の大部分が表面近傍に露出して固定されることが好ましい。表面近傍に固定される定着部材層の量は、樹脂粒子組成物に含まれる定着部材層全量に対し、７０質量％以上、又は９０質量％以上であってよい。 It is preferable that the fixing member layer is chemically and / or physically bonded to the surface thereof so as not to easily fall off from the water-absorbent resin particles in the state before water absorption. The physical bond is realized, for example, by the anchor effect generated by the fixing member layer entering the fine recesses existing on the surface of the water-absorbent resin particles. The fixing member layer may be contained not only on the surface of the water-absorbent resin particles but also inside the water-absorbent resin particles. From the viewpoint of facilitating the manifestation of the effects of the present invention, it is preferable that most of the content of the fixing member layer is exposed and fixed in the vicinity of the surface. The amount of the fixing member layer fixed in the vicinity of the surface may be 70% by mass or more or 90% by mass or more with respect to the total amount of the fixing member layer contained in the resin particle composition.
　定着部材層の熱溶融性樹脂は、ＪＩＳ　Ｚ０２３７に従って測定される引きはがし粘着力が１～５００Ｎ／２５ｍｍ、又は５～３００Ｎ／２５ｍｍであってよい。 The heat-meltable resin of the fixing member layer may have a peeling adhesive strength of 1 to 500 N / 25 mm or 5 to 300 N / 25 mm as measured according to JIS Z0237.
　吸水性樹脂粒子の表面面積に対する定着部材層による占有割合（すなわち被覆率）は、３０％以上、４０％以上、５０％以上、６０％以上、７０％以上、８０％以上、８５％以上、９０％以上、９５％以上、９８％以上、又は９９％以上であってよく、１００％以下、９９％以下、９８％以下、９５％以下、９０％以下、又は８０％以下であってよい。被覆率は、ＲＡＭＡＮ　ｔｏｕｃｈ（ナノフォトン社製）により算出される。 The occupancy ratio (that is, coverage) of the fixing member layer to the surface area of the water-absorbent resin particles is 30% or more, 40% or more, 50% or more, 60% or more, 70% or more, 80% or more, 85% or more, 90. % Or more, 95% or more, 98% or more, or 99% or more, and may be 100% or less, 99% or less, 98% or less, 95% or less, 90% or less, or 80% or less. The coverage is calculated by RAMAN touch (manufactured by Nanophoton).
　樹脂粒子組成物の定着部材層の厚みは、０．００１～１００μｍ、０．０１～５０μｍ、又は０．１～３０μｍであってよい。 The thickness of the fixing member layer of the resin particle composition may be 0.001 to 100 μm, 0.01 to 50 μm, or 0.1 to 30 μm.
　樹脂粒子組成物において、定着部材層の量は、吸水性樹脂粒子１００質量部に対して、０．０１質量部以上、０．０５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、１．５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５質量部以上であってよく、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。 In the resin particle composition, the amount of the fixing member layer is 0.01 part by mass or more, 0.05 part by mass or more, 0.1 part by mass or more, and 0.5 part by mass with respect to 100 parts by mass of the water-absorbent resin particles. It may be 1 part by mass or more, 1.5 parts by mass or more, 2 parts by mass or more, 3 parts by mass or more, 4 parts by mass or more, or 5 parts by mass or more, and 10 parts by mass or less, 8 parts by mass or less, or It may be 6 parts by mass or less.
［吸水性樹脂粒子］
　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の重合により形成された架橋重合体を含んでいてよい。該架橋重合体は、エチレン性不飽和単量体に由来する単量体単位を有することができる。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る工程を含む方法により、製造することができる。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。 [Water-absorbent resin particles]
The water-absorbent resin particles may contain, for example, a crosslinked polymer formed by polymerizing a monomer containing an ethylenically unsaturated monomer. The crosslinked polymer can have a monomeric unit derived from an ethylenically unsaturated monomer. The water-absorbent resin particles can be produced, for example, by a method including a step of polymerizing a monomer containing an ethylenically unsaturated monomer. Examples of the polymerization method include a reverse phase suspension polymerization method, an aqueous solution polymerization method, a bulk polymerization method, a precipitation polymerization method and the like.
　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であってもよい。水溶性エチレン性不飽和単量体としては、例えば、（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、単独で用いられてもよく、２種以上を組み合わせて用いられてもよい。 The ethylenically unsaturated monomer may be a water-soluble ethylenically unsaturated monomer. Examples of the water-soluble ethylenically unsaturated monomer include (meth) acrylic acid and its salt, 2- (meth) acrylamide-2-methylpropanesulfonic acid and its salt, (meth) acrylamide, N, N-dimethyl. (Meta) acrylamide, 2-hydroxyethyl (meth) acrylate, N-methylol (meth) acrylamide, polyethylene glycol mono (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, N, N-diethylaminopropyl (meth) Examples thereof include acrylate and diethylaminopropyl (meth) acrylamide. When the ethylenically unsaturated monomer has an amino group, the amino group may be quaternized. The ethylenically unsaturated monomer may be used alone or in combination of two or more.
　エチレン性不飽和単量体が酸基を有する場合、その酸基をアルカリ性中和剤によって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、アルカリ性中和剤による中和度は、例えば、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％であってもよい。 When the ethylenically unsaturated monomer has an acid group, the acid group may be neutralized with an alkaline neutralizing agent and then used in the polymerization reaction. The degree of neutralization of the ethylenically unsaturated monomer by the alkaline neutralizing agent is, for example, 10 to 100 mol%, 50 to 90 mol%, or 60 to 80 mol% of the acidic group in the ethylenically unsaturated monomer. May be%.
　工業的に入手が容易である観点から、エチレン性不飽和単量体は、（メタ）アクリル酸及びその塩、アクリルアミド、メタクリルアミド、並びに、Ｎ，Ｎ－ジメチルアクリルアミドからなる群より選ばれる少なくとも１種の化合物を含んでいてもよい。エチレン性不飽和単量体が、（メタ）アクリル酸及びその塩、並びに、アクリルアミドからなる群より選ばれる少なくとも１種の化合物を含んでいてもよい。 From the viewpoint of industrial availability, the ethylenically unsaturated monomer is at least one selected from the group consisting of (meth) acrylic acid and salts thereof, acrylamide, methacrylamide, and N, N-dimethylacrylamide. It may contain a compound of the species. The ethylenically unsaturated monomer may contain (meth) acrylic acid and a salt thereof, and at least one compound selected from the group consisting of acrylamide.
　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、単量体全量に対して７０～１００モル％であってもよい。（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％であってもよい。 As the monomer for obtaining the water-absorbent resin particles, 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 may be 70 to 100 mol% with respect to the total amount of the monomers. The ratio of (meth) acrylic acid and a salt thereof may be 70 to 100 mol% with respect to the total amount of the monomer.
　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施してもよい。内部架橋剤を用いると、吸水性樹脂粒子の吸水特性（保水量等）を制御しやすい。内部架橋剤は、通常、重合反応の際に反応液に添加される。 Cross-linking may occur by self-cross-linking during polymerization, but cross-linking may be performed by using an internal cross-linking agent. When an internal cross-linking agent is used, it is easy to control the water absorption characteristics (water retention amount, etc.) of the water-absorbent resin particles. The internal cross-linking agent is usually added to the reaction solution during the polymerization reaction.
　吸水性樹脂粒子は、表面近傍の架橋（表面架橋）が行われたものであってもよい。また、吸水性樹脂粒子は、重合体粒子（架橋重合体）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、及び流動性向上剤（滑剤）等から選ばれる各種の追加の成分を更に含んでいてもよい。追加の成分は、重合体粒子の内部、重合体粒子の表面上、又はそれらの両方に配置され得る。追加の成分は、流動性向上剤（滑剤）であってもよい。流動性向上剤は無機粒子を含んでいてもよい。無機粒子としては、例えば、非晶質シリカ等のシリカ粒子が挙げられる。 The water-absorbent resin particles may be crosslinked (surface crosslinked) in the vicinity of the surface. Further, the water-absorbent resin particles may be composed of only polymer particles (crosslinked polymers), but various types selected from, for example, gel stabilizers, metal chelating agents, fluidity improving agents (lubricants) and the like. It may further contain additional ingredients. Additional components may be placed inside the polymer particles, on the surface of the polymer particles, or both. The additional component may be a fluidity improver (lubricant). The fluidity improver may contain inorganic particles. Examples of the inorganic particles include silica particles such as amorphous silica.
　吸水性樹脂粒子の形状は、例えば略球状、破砕状又は多孔質状であってもよく、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。なかでも、吸収体作製時における樹脂粒子の分散のしやすさの観点から、略球状、又はその凝集形状であることが好ましい。 The shape of the water-absorbent resin particles may be, for example, substantially spherical, crushed or porous, and may be a shape in which primary particles having these shapes are aggregated. Above all, from the viewpoint of easy dispersion of the resin particles at the time of producing the absorber, a substantially spherical shape or an aggregated shape thereof is preferable.
［樹脂粒子組成物の製造方法］
　本実施形態に係る樹脂粒子組成物は、例えば、吸水性樹脂粒子と定着部材とを混合して、該吸水性樹脂粒子の表面の少なくとも一部に定着部材層を形成する工程を含んでよい。 [Manufacturing method of resin particle composition]
The resin particle composition according to the present embodiment may include, for example, a step of mixing the water-absorbent resin particles and the fixing member to form a fixing member layer on at least a part of the surface of the water-absorbent resin particles.
　混合に用いられる定着部材の量は、吸水性樹脂粒子１００質量部に対して、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、又は３質量部以上であってよく、１０質量部以下、８質量部以下、又は６質量部以下であってもよい。 The amount of the fixing member used for mixing is 0.1 part by mass or more, 0.5 part by mass or more, 1 part by mass or more, 2 parts by mass or more, or 3 parts by mass or more with respect to 100 parts by mass of the water-absorbent resin particles. It may be 10 parts by mass or less, 8 parts by mass or less, or 6 parts by mass or less.
　定着部材は、例えば、上述の定着部材層を形成し得る熱溶融性樹脂である。樹脂とは、通常、繰り返し単位から構成される重合体を含む。定着部材は、熱溶融性重合体そのものだけでなく、その単量体、前駆体等の形成材料を含んでもよい。 The fixing member is, for example, a heat-meltable resin capable of forming the above-mentioned fixing member layer. The resin usually contains a polymer composed of repeating units. The fixing member may contain not only the heat-meltable polymer itself but also a forming material such as a monomer or a precursor thereof.
　例えば、定着部材層がポリウレタンを含む場合、定着部材は、ポリウレタンそのものを含んでいてもよいし、該ポリウレタンの形成材料であるポリオール及びポリイソシアネートを含んでいてもよい。 For example, when the fixing member layer contains polyurethane, the fixing member may contain polyurethane itself, or may contain a polyol and a polyisocyanate which are materials for forming the polyurethane.
　定着部材が、重合体の形成材料（前駆体以外）を含む場合、本実施形態に係る樹脂粒子組成物の製造方法は、好ましくは、吸水性樹脂粒子と定着部材とを混合した後、該定着部材を重合する工程を更に備える。以下、樹脂粒子組成物の具体的な製造方法について、定着部材の状態別に説明する。 When the fixing member contains a polymer forming material (other than a precursor), the method for producing the resin particle composition according to the present embodiment is preferably after mixing the water-absorbent resin particles and the fixing member. It further comprises a step of polymerizing the members. Hereinafter, a specific method for producing the resin particle composition will be described for each state of the fixing member.
＜固体状の定着部材を用いる場合＞
　この場合、粒子複合化装置を用いて吸水性樹脂粒子の表面に定着部材を固定させ、定着部材層を形成し得る。具体的には、該粒子複合化装置に所定量の吸水性樹脂粒子と固体（例えば粉状）の定着部材を投入する。その後、装置に備えられた撹拌翼の回転により、吸水性樹脂粒子及び定着部材に応力（圧縮応力及び剪断応力）を加え、該応力により吸水性樹脂粒子の表面に定着部材を圧着させることにより樹脂粒子組成物を作製する。 <When using a solid fixing member>
In this case, the fixing member can be fixed to the surface of the water-absorbent resin particles by using the particle composite device to form the fixing member layer. Specifically, a predetermined amount of water-absorbent resin particles and a solid (for example, powdery) fixing member are charged into the particle composite device. After that, stress (compressive stress and shear stress) is applied to the water-absorbent resin particles and the fixing member by the rotation of the stirring blade provided in the apparatus, and the fixing member is crimped to the surface of the water-absorbent resin particles by the stress. A particle composition is prepared.
　この場合、粒子複合化装置に投入する吸水性樹脂粒子及び定着部材の量を適宜調整することにより、定着部材層の厚みや被覆率などを任意に調整し得る。なお、吸水性樹脂粒子と定着部材とは別々に粒子複合化装置に投入してもよいが、より均一な分散及び被覆が期待できることから、あらかじめ吸水性樹脂粒子と定着部材を混合した状態で粒子複合化装置に投入することが好ましい。粒子複合化装置を用いた場合、吸水性樹脂粒子の表面の少なくとも一部に定着部材層が固定された樹脂粒子組成物が得られやすい。粒子複合化装置としては、例えば、粒子複合化装置ノビルタＭＩＮＩ（スギノマシン株式会社製）を使用できる。 In this case, the thickness and coverage of the fixing member layer can be arbitrarily adjusted by appropriately adjusting the amounts of the water-absorbent resin particles and the fixing member to be charged into the particle composite device. The water-absorbent resin particles and the fixing member may be separately charged into the particle composite device, but since more uniform dispersion and coating can be expected, the particles are in a state where the water-absorbent resin particles and the fixing member are mixed in advance. It is preferable to put it in the composite device. When the particle composite device is used, it is easy to obtain a resin particle composition in which a fixing member layer is fixed to at least a part of the surface of the water-absorbent resin particles. As the particle compounding device, for example, the particle compounding device Novirta MINI (manufactured by Sugino Machine Limited) can be used.
＜液状の定着部材を用いる場合＞
　液状の定着部材（以下、単に「定着部材液」と称する。）は、例えば、定着部材を溶融させて得ることもでき、定着部材を任意の溶媒又は分散媒に溶解又は分散させて得ることもできる。均一な厚みの定着部材層を形成しやすいことから、定着部材液は、定着部材を任意の溶媒又は分散媒に溶解又は分散させて得ることが好ましい。定着部材液が溶液となるか分散液となるかは、定着部材の性質及び用いる媒質によって定まる。 <When using a liquid fixing member>
The liquid fixing member (hereinafter, simply referred to as "fixing member liquid") can be obtained by melting the fixing member, or can be obtained by dissolving or dispersing the fixing member in an arbitrary solvent or dispersion medium. can. Since it is easy to form a fixing member layer having a uniform thickness, the fixing member liquid is preferably obtained by dissolving or dispersing the fixing member in an arbitrary solvent or dispersion medium. Whether the fixing member liquid becomes a solution or a dispersion liquid is determined by the properties of the fixing member and the medium used.
　溶媒又は分散媒としては、例えば、水、親水性化合物、水と親水性化合物の混合物、炭化水素化合物等が挙げられる。親水性化合物は、水に略均一に溶解する化合物である。親水性化合物としては、例えば、メタノール、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；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。炭化水素化合物としては、例えば、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。これらは、単独で用いられてもよく、２種以上を組み合わせて用いられてもよい。 Examples of the solvent or dispersion medium include water, a hydrophilic compound, a mixture of water and a hydrophilic compound, a hydrocarbon compound, and the like. The hydrophilic compound is a compound that dissolves substantially uniformly in water. Examples of the hydrophilic compound include alcohols such as methanol and isopropyl alcohol; glycols such as ethylene glycol; 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. Examples of the hydrocarbon compound include chain aliphatic hydrocarbons such as n-hexane, n-heptane, 2-methylhexane, 3-methylhexane, 2,3-dimethylpentane, 3-ethylpentane, and n-octane; Alicyclic 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, and the like. These may be used alone or in combination of two or more.
　定着部材液中における定着部材の濃度は特に限定されず、目的とする厚みの定着部材層を得るため、吸水性樹脂粒子の量を考慮して適宜調整し得るが、例えば、１～５０質量％、３～３０質量％、又は５～２０質量％であってよい。 The concentration of the fixing member in the fixing member liquid is not particularly limited, and can be appropriately adjusted in consideration of the amount of water-absorbent resin particles in order to obtain a fixing member layer having a desired thickness. It may be 3 to 30% by mass, or 5 to 20% by mass.
　定着部材液を用いる場合、定着部材層は、例えば、（１）吸水性樹脂粒子が分散した炭化水素分散媒に定着部材液を添加する方法、（２）炭化水素分散媒に定着部材液及び吸水性樹脂粒子を略同時に添加する方法、（３）乾燥状態にある吸水性樹脂粒子に定着部材液を接触させる方法、（４）吸水性樹脂粒子の存在下で定着部材を重合させる方法、又は（５）吸水性樹脂粒子の存在下で、架橋剤を用いて定着部材（前駆体を含む）を架橋させる方法により形成し得る。以下、各方法について具体的に説明する。 When the fixing member liquid is used, the fixing member layer is, for example, (1) a method of adding the fixing member liquid to the hydrocarbon dispersion medium in which the water-absorbent resin particles are dispersed, and (2) the fixing member liquid and water absorption in the hydrocarbon dispersion medium. A method of adding the sex resin particles substantially at the same time, (3) a method of bringing the fixing member liquid into contact with the water-absorbent resin particles in a dry state, (4) a method of polymerizing the fixing member in the presence of the water-absorbent resin particles, or ( 5) It can be formed by a method of cross-linking a fixing member (including a precursor) with a cross-linking agent in the presence of water-absorbent resin particles. Hereinafter, each method will be specifically described.
　上記（１）の方法の一例について説明する。まず、還流冷却器、滴下ロート、窒素ガス導入管、及び撹拌機を備えたセパラブルフラスコを準備する。続いて、該フラスコに、炭化水素分散媒及び吸水性樹脂粒子を投入し、高温（例えば、６０～８０℃）を維持しつつ十分に撹拌する。一方、ビーカーに、溶媒又は分散媒と、定着部材とを加えて混合し、定着部材液を調製する。定着部材液を上記フラスコ内に添加して十分に撹拌した後、高温（例えば、１００～１２５℃）に設定した油浴にフラスコを浸漬し、炭化水素分散媒と水との共沸蒸留により、炭化水素分散媒を還流しながら、反応系に含まれ得る水を系外へ抜き出す。その後、炭化水素分散媒を蒸発させることにより、定着部材が吸水性樹脂粒子の表面に固定された樹脂粒子組成物が得られる。 An example of the method (1) above will be described. First, a separable flask equipped with a reflux condenser, a dropping funnel, a nitrogen gas introduction tube, and a stirrer is prepared. Subsequently, the hydrocarbon dispersion medium and the water-absorbent resin particles are put into the flask, and the flask is sufficiently stirred while maintaining a high temperature (for example, 60 to 80 ° C.). On the other hand, a solvent or a dispersion medium and a fixing member are added to the beaker and mixed to prepare a fixing member liquid. After adding the fixing member liquid into the flask and stirring sufficiently, the flask is immersed in an oil bath set at a high temperature (for example, 100 to 125 ° C.), and the hydrocarbon dispersion medium and water are co-distilled. While refluxing the hydrocarbon dispersion medium, water that may be contained in the reaction system is extracted from the system. Then, by evaporating the hydrocarbon dispersion medium, a resin particle composition in which the fixing member is fixed on the surface of the water-absorbent resin particles can be obtained.
　上記（２）の方法の一例について説明する。まず、還流冷却器、滴下ロート、窒素ガス導入管、及び撹拌機を備えたセパラブルフラスコを準備する。続いて、該フラスコに、炭化水素分散媒、吸水性樹脂粒子、及び定着部材液を投入し、高温（例えば、６０～８０℃）を維持しつつ十分に撹拌する。その後、炭化水素分散媒を蒸発させることにより、定着部材が吸水性樹脂粒子の表面に固定された樹脂粒子組成物が得られる。 An example of the method (2) above will be described. First, a separable flask equipped with a reflux condenser, a dropping funnel, a nitrogen gas introduction tube, and a stirrer is prepared. Subsequently, the hydrocarbon dispersion medium, the water-absorbent resin particles, and the fixing member liquid are put into the flask, and the flask is sufficiently stirred while maintaining a high temperature (for example, 60 to 80 ° C.). Then, by evaporating the hydrocarbon dispersion medium, a resin particle composition in which the fixing member is fixed on the surface of the water-absorbent resin particles can be obtained.
　上記（３）の方法は様々であるが、以下、その代表例として（３－１）ナスフラスコを用いた方法、（３－２）噴霧器を用いた方法、（３－３）各種造粒機を用いた方法について説明する。 The above method (3) is various, but the following are typical examples thereof: (3-1) a method using an eggplant flask, (3-2) a method using an atomizer, and (3-3) various granulators. The method using the above will be described.
（３－１）
　ナスフラスコに定着部材液を投入し、続けて吸水性樹脂粒子を投入する。該ナスフラスコをエバポレーターに取り付け、回転させながら加熱し、減圧条件下で定着部材液に含まれる溶媒又は分散媒を留去する。これにより定着部材が吸水性樹脂粒子の表面に固定された樹脂粒子組成物が得られる。 (3-1)
The fixing member liquid is charged into the eggplant flask, and then the water-absorbent resin particles are charged. The eggplant flask is attached to an evaporator and heated while rotating to distill off the solvent or dispersion medium contained in the fixing member liquid under reduced pressure conditions. As a result, a resin particle composition in which the fixing member is fixed on the surface of the water-absorbent resin particles can be obtained.
（３－２）
　撹拌翼を備えたセパラブルフラスコに、吸水性樹脂粒子を加えて撹拌する。撹拌翼による撹拌で巻き上げられた吸水性樹脂粒子に、定着部材液を噴霧する。定着部材液の噴霧は、例えば、２流体型ノズルを用いて行うことができる。均一な分散及び被覆が期待できることから、定着部材液は窒素等の不活性ガスの気流により霧状にして噴霧されることが望ましい。その後、フラスコの内容物を取り出し、熱風乾燥機にて加熱した後、室温まで冷却することで樹脂粒子組成物が得られる。 (3-2)
Water-absorbent resin particles are added to a separable flask equipped with a stirring blade and stirred. The fixing member liquid is sprayed on the water-absorbent resin particles wound up by stirring with the stirring blade. The fixing member liquid can be sprayed, for example, by using a two-fluid type nozzle. Since uniform dispersion and coating can be expected, it is desirable that the fixing member liquid is atomized and sprayed by an air flow of an inert gas such as nitrogen. Then, the contents of the flask are taken out, heated by a hot air dryer, and then cooled to room temperature to obtain a resin particle composition.
（３－３）
　樹脂粒子組成物の製造に用いられる造粒機としては、例えば、転動造粒機、撹拌造粒機、流動層造粒機等が挙げられる。 (3-3)
Examples of the granulator used for producing the resin particle composition include a rolling granulator, a stirring granulator, a fluidized bed granulator, and the like.
　転動造粒機を用いる場合、転動造粒機に備え付けられた、傾斜した浅い円形容器を回転させておき、該円形容器に吸水性樹脂粒子を供給するとともに定着部材液を適量添加する。そうすると、定着部材液に含まれる溶媒又は分散媒により、転動中の吸水性樹脂粒子の一部が凝集しつつその表面に定着部材層が形成される。なお、吸水性樹脂粒子及び定着部材液の添加工程は必要により複数回行い得る。 When using a rolling granulator, a shallow, inclined circular container provided in the rolling granulator is rotated, water-absorbent resin particles are supplied to the circular container, and an appropriate amount of fixing member liquid is added. Then, a part of the water-absorbent resin particles during rolling is aggregated by the solvent or the dispersion medium contained in the fixing member liquid, and the fixing member layer is formed on the surface thereof. The step of adding the water-absorbent resin particles and the fixing member liquid may be performed a plurality of times if necessary.
　撹拌造粒機を用いる場合、撹拌造粒機に備え付けられたミキサーに吸水性樹脂粒子を投入し、撹拌による混合を行うとともに定着部材液を添加する。そうすると、定着部材液に含まれる溶媒又は分散媒により、撹拌中の吸水性樹脂粒子の一部が凝集しつつその表面に定着部材層が形成される。吸水性樹脂粒子及び定着部材液の添加工程は必要により複数回行い得る。なお、吸水性樹脂粒子の過度な凝集は、ミキサーの剪断力を制御することによって抑制し得る。 When using a stirring granulator, the water-absorbent resin particles are put into a mixer installed in the stirring granulator, mixed by stirring, and the fixing member liquid is added. Then, a part of the water-absorbent resin particles during stirring is aggregated by the solvent or the dispersion medium contained in the fixing member liquid, and the fixing member layer is formed on the surface thereof. The step of adding the water-absorbent resin particles and the fixing member liquid may be performed a plurality of times if necessary. Excessive aggregation of the water-absorbent resin particles can be suppressed by controlling the shearing force of the mixer.
　流動層造粒機を用いる場合、まず、流動層造粒機に備え付けられた、下部から熱風を送り出すことができる容器に吸水性樹脂粒子を投入し、あらかじめ吸水性樹脂粒子を流動化しておく。その後、該容器に備え付けられたノズルから定着部材液を散布すると、定着部材液に含まれる溶媒又は分散媒により、撹拌中の吸水性樹脂粒子の一部が凝集しつつその表面に定着部材層が形成される。定着部材液の散布は必要により複数回行い得る。なお、吸水性樹脂粒子の過度な凝集は、定着部材液の散布量や散布頻度を調整することで抑制し得る。流動層造粒機としては、例えば、流動層造粒機ＦＢＤ／ＳＧ（ミューチュアル株式会社製）を使用できる。 When using a fluidized bed granulator, first, the water-absorbent resin particles are put into a container equipped in the fluidized bed granulator that can send out hot air from the lower part, and the water-absorbent resin particles are fluidized in advance. After that, when the fixing member liquid is sprayed from the nozzle provided in the container, a part of the water-absorbent resin particles during stirring is aggregated by the solvent or the dispersion medium contained in the fixing member liquid, and the fixing member layer is formed on the surface thereof. It is formed. The fixing member liquid may be sprayed multiple times if necessary. Excessive aggregation of the water-absorbent resin particles can be suppressed by adjusting the spraying amount and spraying frequency of the fixing member liquid. As the fluidized bed granulator, for example, a fluidized bed granulator FBD / SG (manufactured by Mutual Co., Ltd.) can be used.
　上記（４）の方法の一例について説明する。まず、公知の逆相懸濁重合法により、セパラブルフラスコ内に含水したゲル状の吸水性樹脂粒子を作製する。吸水性樹脂粒子は、１段重合で得られたものであってもよく、２段以上の多段重合で得られたものであってもよい。他方、定着部材、重合開始剤、及び必要により内部架橋剤を含んだ定着部材の単量体水溶液を用意する。定着部材は、例えば、定着部材層がポリウレタンを含む場合、ポリオール及びポリイソシアネートを含む。 An example of the method (4) above will be described. First, gel-like water-absorbent resin particles containing water in a separable flask are prepared by a known reverse-phase suspension polymerization method. The water-absorbent resin particles may be obtained by one-stage polymerization or may be obtained by two-stage or more multi-stage polymerization. On the other hand, a monomer aqueous solution of the fixing member containing the fixing member, the polymerization initiator, and, if necessary, the internal cross-linking agent is prepared. The fixing member contains, for example, a polyol and a polyisocyanate when the fixing member layer contains polyurethane.
　続いて、セパラブルフラスコ内から、共沸蒸留により炭化水素分散媒を還流させながら水をある程度抜き出した後、該フラスコに上記定着部材の単量体水溶液を投入し、重合反応を開始させる。その後、フラスコ内の炭化水素分散媒を蒸発させることにより、定着部材層（定着部材の重合体）が吸水性樹脂粒子の表面に固定された樹脂粒子組成物が得られる。 Subsequently, water is withdrawn to some extent from the separable flask while refluxing the hydrocarbon dispersion medium by azeotropic distillation, and then the monomer aqueous solution of the fixing member is put into the flask to start the polymerization reaction. Then, by evaporating the hydrocarbon dispersion medium in the flask, a resin particle composition in which the fixing member layer (polymer of the fixing member) is fixed on the surface of the water-absorbent resin particles can be obtained.
（５－１）
　上記（５）の方法の一例について説明する。まず、公知の逆相懸濁重合法により、セパラブルフラスコ内に含水したゲル状の吸水性樹脂粒子を作製する。吸水性樹脂粒子は、１段重合で得られたものであってもよく、２段以上の多段重合で得られたものであってもよい。他方、定着部材（前駆体を含む）及び架橋剤を含んだ前駆体水溶液を用意する。 (5-1)
An example of the method (5) above will be described. First, gel-like water-absorbent resin particles containing water in a separable flask are prepared by a known reverse-phase suspension polymerization method. The water-absorbent resin particles may be obtained by one-stage polymerization or may be obtained by two-stage or more multi-stage polymerization. On the other hand, a precursor aqueous solution containing a fixing member (including a precursor) and a cross-linking agent is prepared.
　続いて、セパラブルフラスコ内から、共沸蒸留により炭化水素分散媒を還流させながら水をある程度抜き出した後、該フラスコに上記前駆体水溶液を投入し、架橋反応を開始させる。その後、フラスコ内の炭化水素分散媒を蒸発させることにより、定着部材層（定着部材の架橋物である定着部材の重合体）が吸水性樹脂粒子の表面に固定された樹脂粒子組成物が得られる。 Subsequently, water is withdrawn to some extent from the separable flask while refluxing the hydrocarbon dispersion medium by azeotropic distillation, and then the precursor aqueous solution is put into the flask to start the cross-linking reaction. Then, by evaporating the hydrocarbon dispersion medium in the flask, a resin particle composition in which the fixing member layer (polymer of the fixing member which is a crosslinked product of the fixing member) is fixed on the surface of the water-absorbent resin particles can be obtained. ..
（５－２）
　上記（５）の方法の他例について説明する。まず、上記５－１と同様に含水したゲル状の吸水性樹脂粒子を作製する。続いて、この粒子を脱水し、乾燥した吸水性樹脂粒子を得る。乾燥した吸水性樹脂粒子を適当な分散媒（例えば、ｎ－ヘプタンなど）に分散させ、その状態で定着部材Ａ（例えば、ポリオール）及び定着部材Ｂ（例えば、ポリイソシアネート）を順に添加し、必要に応じて加熱することにより、定着部材Ａと定着部材Ｂの重合反応によって生成された重合体（定着部材層）が吸水性樹脂粒子の表面に固定された樹脂粒子組成物が得られる。 (5-2)
Another example of the method (5) above will be described. First, gel-like water-absorbent resin particles containing water are produced in the same manner as in 5-1 above. Subsequently, the particles are dehydrated to obtain dried water-absorbent resin particles. The dried water-absorbent resin particles are dispersed in an appropriate dispersion medium (for example, n-heptane), and in that state, the fixing member A (for example, polyol) and the fixing member B (for example, polyisocyanate) are added in order, and it is necessary. By heating according to the above, a resin particle composition in which the polymer (fixing member layer) produced by the polymerization reaction between the fixing member A and the fixing member B is fixed on the surface of the water-absorbent resin particles can be obtained.
　定着部材液を用いて定着部材層を形成すると、吸水性樹脂粒子に均一に定着部材が接触しやすいため、得られる樹脂粒子組成物が吸収体における脱落防止を発現しやすいと考えられる。特に、上記（１）、（２）、（３）の流動層造粒機を用いた方法、（４）、及び（５）の方法は、その他の方法に比べてより均一な厚みの定着部材層が得られやすいと考えられる。 When the fixing member layer is formed using the fixing member liquid, the fixing member is likely to come into uniform contact with the water-absorbent resin particles, so that it is considered that the obtained resin particle composition is likely to exhibit prevention of falling off in the absorber. In particular, the methods (1), (2), and (3) using the fluidized bed granulator, (4), and (5) have a more uniform thickness of the fixing member than the other methods. It is thought that the layer is easy to obtain.
　本実施形態に係る樹脂粒子組成物は、紙おむつ、生理用品等の衛生材料、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分野に用いることが好適である。 The resin particle composition according to the present embodiment may be used in fields such as disposable diapers, sanitary materials such as sanitary products, agricultural and horticultural materials such as water retention agents and soil conditioners, and industrial materials such as water blocking agents and dew condensation inhibitors. Suitable.
　以下、実施例を挙げて本発明について更に具体的に説明する。ただし、本発明はこれら実施例に限定されるものではない。 Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples.
［実施例１］
（吸水性樹脂粒子の作製）
　還流冷却器、滴下ロート、窒素ガス導入管、及び、撹拌機として、翼径５ｃｍの４枚傾斜パドル翼を２段で有する撹拌翼を備えた内径１１ｃｍ、２Ｌ容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、炭化水素分散媒としてｎ－ヘプタン２９３ｇを入れ、高分子系分散剤として無水マレイン酸変性エチレン・プロピレン共重合体（三井化学株式会社、ハイワックス１１０５Ａ）０．７３６ｇを添加した。フラスコ内の混合液を撹拌しつつ８０℃まで昇温して分散剤を溶解し、その後５０℃まで冷却した。 [Example 1]
(Preparation of water-absorbent resin particles)
A round-bottomed cylindrical separable flask with an inner diameter of 11 cm and a capacity of 2 L, equipped with a reflux condenser, a dropping funnel, a nitrogen gas introduction pipe, and a stirring blade having four inclined paddle blades with a blade diameter of 5 cm in two stages as a stirrer. Prepared. To this flask, 293 g of n-heptane was added as a hydrocarbon dispersion medium, and 0.736 g of a maleic anhydride-modified ethylene-propylene copolymer (Mitsui Chemicals, Inc., High Wax 1105A) was added as a polymer-based dispersant. The mixture in the flask was heated to 80 ° C. with stirring to dissolve the dispersant, and then cooled to 50 ° C.
　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（１．０３モル）を入れ、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を滴下して７５モル％の中和を行った。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、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）、及び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）を加えて溶解し、第１段目の単量体水溶液を調製した。 In a beaker with an internal volume of 300 mL, 92.0 g (1.03 mol) of an 80.5 mass% acrylic acid aqueous solution as a water-soluble ethylenically unsaturated monomer was placed, and while being cooled from the outside, 20.9 mass% was added. 147.7 g of an aqueous sodium hydroxide solution was added dropwise to neutralize 75 mol%. After that, 0.092 g of hydroxyethyl cellulose (Sumitomo Seika Co., Ltd., HEC AW-15F) as a thickener, 0.0736 g (0.272 mmol) of potassium persulfate as a water-soluble radical polymerization initiator, and ethylene as an internal cross-linking agent. 0.010 g (0.057 mmol) of glycol diglycidyl ether was added and dissolved to prepare a first-stage monomer aqueous solution.
　ｎ－ヘプタン６．６２ｇに界面活性剤としてのショ糖ステアリン酸エステル（ＨＬＢ：３、三菱化学フーズ株式会社、リョートーシュガーエステルＳ－３７０）０．７３６ｇを加熱溶解して界面活性剤溶液を調製した。第１段目の単量体水溶液をフラスコに添加して１０分間撹拌した後、上記界面活性剤溶液を添加して、撹拌機の回転数を５００ｒｐｍとして撹拌しながら系内を窒素で十分に置換した。その後、フラスコを７０℃の水浴に浸漬して昇温し、重合を６０分間行うことにより、第１段目の重合スラリー液を得た。 Prepare a surfactant solution by heating and dissolving 0.736 g of sucrose stearic acid ester (HLB: 3, Mitsubishi Chemical Foods Co., Ltd., Ryoto Sugar Ester S-370) as a surfactant in 6.62 g of n-heptane. did. After adding the first-stage monomer aqueous solution to the flask and stirring for 10 minutes, the above-mentioned surfactant solution was added, and the inside of the system was sufficiently replaced with nitrogen while stirring at a stirring speed of 500 rpm. did. Then, the flask was immersed in a water bath at 70 ° C. to raise the temperature, and the polymerization was carried out for 60 minutes to obtain a first-stage polymerization slurry liquid.
　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（１．４４モル）を入れ、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を滴下して７５モル％の中和を行った。その後、水溶性ラジカル重合開始剤として過硫酸カリウム０．０９０ｇ（０．３３３ミリモル）、及び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）を加えて溶解し、第２段目の単量体水溶液を調製した。 Next, 128.8 g (1.44 mol) of an 80.5 mass% acrylic acid aqueous solution as a water-soluble ethylenically unsaturated monomer was placed in another beaker having an internal volume of 500 mL, and 27 mass while cooling from the outside. 159.0 g of a% aqueous sodium hydroxide solution was added dropwise to neutralize 75 mol%. Then, 0.090 g (0.333 mmol) of potassium persulfate as a water-soluble radical polymerization initiator and 0.0116 g (0.067 mmol) of ethylene glycol diglycidyl ether as an internal cross-linking agent were added and dissolved to dissolve them in the second stage. An aqueous solution of the eye monomer was prepared.
　撹拌機の回転数を１０００ｒｐｍとして撹拌しながら、上記フラスコ系内を２５℃に冷却した後、第２段目の単量体水溶液の全量を第１段目の重合スラリー液に添加して、系内を窒素で３０分間置換した。その後再度フラスコを７０℃の水浴に浸漬して昇温し、重合反応を６０分間行って、含水ゲル状重合体を得た。 The inside of the flask system was cooled to 25 ° C. while stirring at a stirring speed of 1000 rpm, and then the entire amount of the second-stage monomer aqueous solution was added to the first-stage polymerized slurry liquid to add the system. The inside was replaced with nitrogen for 30 minutes. Then, the flask was immersed in a water bath at 70 ° C. again to raise the temperature, and the polymerization reaction was carried out for 60 minutes to obtain a hydrogel-like polymer.
　得られた含水ゲル状重合体に、４５質量％のジエチレントリアミン５酢酸５ナトリウム水溶液０．５８９ｇを撹拌下で添加した。その後、１２５℃に設定した油浴にフラスコを浸漬し、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、２５７．２ｇの水を系外へ抜き出した。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、８３℃で２時間保持した。 To the obtained hydrogel polymer, 0.589 g of a 45% by mass diethylenetriamine-5 sodium acetate aqueous solution was added under stirring. Then, the flask was immersed in an oil bath set at 125 ° C., and 257.2 g of water was extracted from the system while refluxing n-heptane by azeotropic distillation of n-heptane and water. Then, 4.42 g (0.507 mmol) of a 2% by mass ethylene glycol diglycidyl ether aqueous solution was added to the flask as a surface cross-linking agent, and the mixture was kept at 83 ° C. for 2 hours.
　その後、ｎ－ヘプタン及び水を１２５℃の油浴で加熱して蒸発させて乾燥させることによって、重合体粒子の乾燥品を得た。重合体粒子を目開き８５０μｍの篩に通過させ、吸水性樹脂粒子を２３１．２ｇ得た。 Then, n-heptane and water were heated in an oil bath at 125 ° C. to evaporate and dried to obtain a dried product of polymer particles. The polymer particles were passed through a sieve having an opening of 850 μm to obtain 231.2 g of water-absorbent resin particles.
　上記操作を繰り返し、得られた吸水性樹脂粒子を目開き２５０μｍの篩で分級し、粒子径２５０～８５０μｍの吸水性樹脂粒子（Ａ）を５００ｇ以上入手した。吸水性樹脂粒子（Ａ）の保水量は４１ｇ／ｇであった。 The above operation was repeated, and the obtained water-absorbent resin particles were classified by a sieve having an opening of 250 μm, and 500 g or more of the water-absorbent resin particles (A) having a particle diameter of 250 to 850 μm were obtained. The water retention amount of the water-absorbent resin particles (A) was 41 g / g.
（樹脂粒子組成物の作製）
　内容積１Ｌのポリビーカーに、定着部材としてエチレン－アクリル酸ナトリウム共重合体（住友精化株式会社、ザイクセンＮ）の２５％水分散エマルジョン２０．０ｇ、及びイオン交換水３０．０ｇを投入して混合し、定着部材液を得た。 (Preparation of resin particle composition)
In a polybeaker having an internal volume of 1 L, 20.0 g of a 25% aqueous dispersion emulsion of an ethylene-sodium acrylate copolymer (Sumitomo Seika Chemical Co., Ltd., Zyxen N) and 30.0 g of ion-exchanged water were added as fixing members. Mixing was performed to obtain a fixing member liquid.
　流動層造粒機（パウレック株式会社、ＦＤ－ＭＰ―０１）のコンテナに、吸水性樹脂粒子（Ａ）５００．０ｇを投入し、コンテナの下部から５０℃の温風で送風した。次に、送風で巻き上げられている吸水性樹脂粒子に、定着部材液５０．０ｇを乾燥させながら噴霧した。定着部材液を噴霧した後、粒子を５０℃で３０分間乾燥した。乾燥後、中位粒子径３６２μｍの樹脂粒子組成物５０４．５ｇを得た。 500.0 g of water-absorbent resin particles (A) were put into a container of a fluidized bed granulator (Paurek Co., Ltd., FD-MP-01) and blown from the bottom of the container with warm air at 50 ° C. Next, 50.0 g of the fixing member liquid was sprayed on the water-absorbent resin particles wound up by the blast while being dried. After spraying the fixing member liquid, the particles were dried at 50 ° C. for 30 minutes. After drying, 504.5 g of a resin particle composition having a medium particle diameter of 362 μm was obtained.
［実施例２］
　定着部材液を、ポリウレタン（第一工業製薬株式会社、スーパーフレックス２１０）の３５％水分散エマルジョン５７．１ｇをイオン交換水３４２．９ｇで希釈したものに変更したこと以外は、実施例１と同様に行い、中位粒子径３４５μｍの樹脂粒子組成物５０８．１ｇを得た。 [Example 2]
Same as Example 1 except that the fixing member liquid was changed to a solution obtained by diluting 57.1 g of a 35% aqueous dispersion emulsion of polyurethane (Daiichi Kogyo Seiyaku Co., Ltd., Superflex 210) with 342.9 g of ion-exchanged water. To obtain 508.1 g of a resin particle composition having a medium particle diameter of 345 μm.
［実施例３］
　定着部材液を、ナイロン共重合体（住友精化株式会社、セポルジョンＰＡ２００）の４０％水分散エマルジョン６２．５ｇをイオン交換水１８７．５ｇで希釈したものに変更したこと以外は、実施例１と同様に行い、中位粒子径３３６μｍの樹脂粒子組成物５０２．３ｇを得た。 [Example 3]
Example 1 and the fixing member liquid were changed to those obtained by diluting 62.5 g of a 40% aqueous dispersion emulsion of a nylon copolymer (Sumitomo Seika Co., Ltd., Sepoljon PA200) with 187.5 g of ion-exchanged water. The same procedure was carried out to obtain 502.3 g of a resin particle composition having a medium particle diameter of 336 μm.
［実施例４］
　定着部材液を、ポリエチレングリコール（富士フイルム和光純薬株式会社、ポリエチレングリコール６，０００）２０．０ｇをイオン交換水１８０．０ｇで溶解したものに変更したこと、流動層造粒機での温風温度及び乾燥温度を６０℃に変更したこと以外は、実施例１と同様に行い、中位粒子径３４７μｍの樹脂粒子組成物５０８．３ｇを得た。 [Example 4]
The fixing member liquid was changed to one obtained by dissolving 20.0 g of polyethylene glycol (Fujifilm Wako Pure Chemical Industries, Ltd., polyethylene glycol 6,000) in 180.0 g of ion-exchanged water, and warm air in a fluidized bed granulator. The same procedure as in Example 1 was carried out except that the temperature and the drying temperature were changed to 60 ° C. to obtain 508.3 g of a resin particle composition having a medium particle diameter of 347 μm.
［実施例５］
　定着部材液を、エチレン－アクリル酸ナトリウム共重合体（ＳＫ　ｇｌｏｂａｌ　ｃｈｅｍｉｃａｌ、プリマコール）２５．０ｇをテトラヒドロフラン２２５．０ｇに溶解したものに変更したこと、流動層造粒機での温風温度及び乾燥温度を４０℃に変更したこと以外は、実施例１と同様に行い、中位粒子径３３７μｍの樹脂粒子組成物５０２．０ｇを得た。 [Example 5]
The fixing member liquid was changed to one in which 25.0 g of an ethylene-sodium acrylate copolymer (SK particle chemical, primacol) was dissolved in 225.0 g of tetrahydrofuran, and the temperature and drying of hot air in a fluidized bed granulator. The same procedure as in Example 1 was carried out except that the temperature was changed to 40 ° C. to obtain 502.0 g of a resin particle composition having a medium particle diameter of 337 μm.
［実施例６］
（吸水性樹脂粒子の作製） [Example 6]
(Preparation of water-absorbent resin particles)
　還流冷却器、滴下ロート、窒素ガス導入管、及び、撹拌機として、翼径５ｃｍの４枚傾斜パドル翼（フッ素樹脂にて表面処理したもの）を２段で有する撹拌翼を備えた内径１１ｃｍ、２Ｌ容の、４箇所の側壁バッフル付き丸底円筒型セパラブルフラスコ（バッフル長さ：１０ｃｍバッフル幅：７ｍｍ）を準備した。このフラスコに、炭化水素分散媒としてｎ－ヘプタン４５１．４ｇを入れ、界面活性剤としてソルビタンモノラウレート（ノニオンＬＰ－２０Ｒ、ＨＬＢ値：８．６、日油株式会社製）１．２８８ｇを添加した。フラスコ内の混合物を回転数３００ｒｐｍで撹拌しつつ５０℃まで昇温して界面活性剤を溶解させた後、４０℃まで冷却した。 An inner diameter of 11 cm equipped with a reflux condenser, a dropping funnel, a nitrogen gas introduction pipe, and a stirring blade having four inclined paddle blades (surface treated with fluororesin) having a blade diameter of 5 cm in two stages as a stirrer. A 2 L volume, round-bottomed cylindrical separable flask with four side wall baffles (baffle length: 10 cm, baffle width: 7 mm) was prepared. To this flask, add 451.4 g of n-heptane as a hydrocarbon dispersion medium and 1.288 g of sorbitan monolaurate (Nonion LP-20R, HLB value: 8.6, manufactured by NOF CORPORATION) as a surfactant. did. The mixture in the flask was heated to 50 ° C. while stirring at a rotation speed of 300 rpm to dissolve the surfactant, and then cooled to 40 ° C.
　内容積５００ｍＬの三角フラスコに、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（１．０３モル）を入れ、外部より冷却しつつ、２０．９質量％水酸化ナトリウム水溶液１４７．７ｇを滴下して７５モル％の中和を行った。その後、水溶性ラジカル重合開始剤として過硫酸カリウム０．１０１２ｇ（０．３７４ミリモル）を加えて溶解し、単量体水溶液を調製した。 In a triangular flask having an internal volume of 500 mL, 92.0 g (1.03 mol) of an 80.5 mass% acrylic acid aqueous solution as a water-soluble ethylenically unsaturated monomer was placed, and 20.9 mass% was cooled from the outside. 147.7 g of an aqueous sodium hydroxide solution was added dropwise to neutralize 75 mol%. Then, 0.1012 g (0.374 mmol) of potassium persulfate was added and dissolved as a water-soluble radical polymerization initiator to prepare a monomer aqueous solution.
　調製した単量体水溶液を上述のセパラブルフラスコに添加した後、系内を窒素で充分に置換した。その後、撹拌機の回転数７００ｒｐｍでフラスコ内を撹拌しつつ、フラスコを７０℃の水浴に浸漬した。そのまま６０分間保持して重合を完了させることにより含水ゲル状重合体を得た。 After adding the prepared monomer aqueous solution to the above-mentioned separable flask, the inside of the system was sufficiently replaced with nitrogen. Then, the flask was immersed in a water bath at 70 ° C. while stirring the inside of the flask at a rotation speed of 700 rpm of the stirrer. A hydrogel-like polymer was obtained by holding it as it was for 60 minutes to complete the polymerization.
　その後、撹拌機の回転数１０００ｒｐｍで撹拌しつつ、生成した含水ゲル状重合体、ｎ－ヘプタン及び界面活性剤を含む重合液を１０分間混合した。その後、反応液を含むフラスコを１２５℃の油浴に浸漬し、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９７．０ｇの水を系外へ抜き出した。その後、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４．１４ｇ（エチレングリコールジグリシジルエーテル：０．４７５ミリモル）を添加した後、内温８３℃で２時間保持した。 Then, the polymer solution containing the produced hydrogel-like polymer, n-heptane and a surfactant was mixed for 10 minutes while stirring at a stirring speed of 1000 rpm. Then, the flask containing the reaction solution was immersed in an oil bath at 125 ° C., and 97.0 g of water was extracted from the system while refluxing n-heptane by azeotropic distillation of n-heptane and water. Then, 4.14 g (ethylene glycol diglycidyl ether: 0.475 mmol) of 2% by mass of an ethylene glycol diglycidyl ether aqueous solution was added as a surface cross-linking agent, and the mixture was kept at an internal temperature of 83 ° C. for 2 hours.
　ｎ－ヘプタン６．６２ｇに界面活性剤であるソルビタンモノラウレート（商品名：ノニオンＬＰ－２０Ｒ、ＨＬＢ値８．６、日油株式会社製）０．０７４ｇを溶解し、界面活性剤溶液を調製した。該界面活性剤溶液を上記フラスコ内に添加した。 Prepare a surfactant solution by dissolving 0.074 g of sorbitan monolaurate (trade name: Nonion LP-20R, HLB value 8.6, manufactured by Nichiyu Co., Ltd.), which is a surfactant, in 6.62 g of n-heptane. did. The surfactant solution was added into the flask.
　その後、水及びｎ－ヘプタンを１２０℃にて蒸発させ、系内からの蒸発物がほとんど留出されなくなるまで乾燥させることにより乾燥品を得た。この乾燥品を目開き８５０μｍの篩に通過させ、吸水性樹脂粒子を９１．２ｇ得た。 Then, water and n-heptane were evaporated at 120 ° C. and dried until almost no evaporation from the system was distilled off to obtain a dried product. This dried product was passed through a sieve having an opening of 850 μm to obtain 91.2 g of water-absorbent resin particles.
　上記操作を繰り返し、吸水性樹脂粒子（Ｂ）を５００ｇ以上入手した。吸水性樹脂粒子（Ｂ）の保水量は３８ｇ／ｇ、中位粒子径は２０５μｍであった。 By repeating the above operation, 500 g or more of water-absorbent resin particles (B) were obtained. The water-absorbing resin particles (B) had a water retention amount of 38 g / g and a medium particle diameter of 205 μm.
（樹脂粒子組成物の作製）
　定着部材液を、エチレン―アクリル酸ナトリウム共重合体（住友精化株式会社、ザイクセンＮ）の２５％水分散エマルジョン１００．０ｇをイオン交換水１５０．０ｇで希釈したものに変更したこと、及び、吸水性樹脂粒子（Ａ）の代わりに吸水性樹脂粒子（Ｂ）を用いたこと以外は、実施例１と同様な操作を行い、中位粒子径２１３μｍの樹脂粒子組成物５０６．３ｇを得た。 (Preparation of resin particle composition)
The fixing member liquid was changed to 100.0 g of a 25% aqueous dispersion emulsion of an ethylene-sodium acrylate copolymer (Sumitomo Seika Co., Ltd., Zyxen N) diluted with 150.0 g of ion-exchanged water. The same operation as in Example 1 was carried out except that the water-absorbent resin particles (B) were used instead of the water-absorbent resin particles (A), and 506.3 g of a resin particle composition having a medium particle diameter of 213 μm was obtained. ..
［実施例７］
（吸水性樹脂粒子の作製）
　還流冷却器、滴下ロート、窒素ガス導入管、及び、撹拌機として、翼径５ｃｍの４枚傾斜パドル翼を２段で有する撹拌翼を備えた内径１１ｃｍ、２Ｌ容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、炭化水素分散媒としてｎ－ヘプタン２９３ｇを入れ、高分子系分散剤として無水マレイン酸変性エチレン・プロピレン共重合体（三井化学株式会社、ハイワックス１１０５Ａ）０．７３６ｇを添加した。フラスコ内の混合液を撹拌しつつ８０℃まで昇温して分散剤を溶解し、その後５０℃まで冷却した。 [Example 7]
(Preparation of water-absorbent resin particles)
A round-bottomed cylindrical separable flask with an inner diameter of 11 cm and a capacity of 2 L, equipped with a reflux condenser, a dropping funnel, a nitrogen gas introduction pipe, and a stirring blade having four inclined paddle blades with a blade diameter of 5 cm in two stages as a stirrer. Prepared. To this flask, 293 g of n-heptane was added as a hydrocarbon dispersion medium, and 0.736 g of a maleic anhydride-modified ethylene-propylene copolymer (Mitsui Chemicals, Inc., High Wax 1105A) was added as a polymer-based dispersant. The mixture in the flask was heated to 80 ° C. with stirring to dissolve the dispersant, and then cooled to 50 ° C.
　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（１．０３モル）を入れ、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を滴下して７５モル％の中和を行った。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、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）、及び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）を加えて溶解し、第１段目の単量体水溶液を調製した。 In a beaker with an internal volume of 300 mL, 92.0 g (1.03 mol) of an 80.5 mass% acrylic acid aqueous solution as a water-soluble ethylenically unsaturated monomer was placed, and while being cooled from the outside, 20.9 mass% was added. 147.7 g of an aqueous sodium hydroxide solution was added dropwise to neutralize 75 mol%. After that, 0.092 g of hydroxyethyl cellulose (Sumitomo Seika Co., Ltd., HEC AW-15F) as a thickener, 0.0736 g (0.272 mmol) of potassium persulfate as a water-soluble radical polymerization initiator, and ethylene as an internal cross-linking agent. 0.010 g (0.057 mmol) of glycol diglycidyl ether was added and dissolved to prepare a first-stage monomer aqueous solution.
　ｎ－ヘプタン６．６２ｇに界面活性剤としてショ糖ステアリン酸エステル（ＨＬＢ：３、三菱化学フーズ株式会社、リョートーシュガーエステルＳ－３７０）０．７３６ｇを加熱溶解して界面活性剤溶液を調製した。第１段目の単量体水溶液をフラスコに添加して、１０分間撹拌した後、該界面活性剤溶液を上記フラスコに添加して、撹拌機の回転数を５００ｒｐｍとして撹拌しながら系内を窒素で十分に置換した。その後、フラスコを７０℃の水浴に浸漬して昇温し、重合を６０分間行うことにより、第１段目の重合スラリー液を得た。 A surfactant solution was prepared by heating and dissolving 0.736 g of sucrose stearic acid ester (HLB: 3, Mitsubishi Chemical Foods Co., Ltd., Ryoto Sugar Ester S-370) as a surfactant in 6.62 g of n-heptane. .. After adding the first-stage monomer aqueous solution to the flask and stirring for 10 minutes, the surfactant solution is added to the flask, and the inside of the system is stirred while stirring at a stirring speed of 500 rpm. Was sufficiently replaced with. Then, the flask was immersed in a water bath at 70 ° C. to raise the temperature, and the polymerization was carried out for 60 minutes to obtain a first-stage polymerization slurry liquid.
　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（１．４４モル）を入れ、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を滴下して７５モル％の中和を行った。その後、水溶性ラジカル重合開始剤として過硫酸カリウム０．０９０ｇ（０．３３３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０．０１１６ｇ（０．０６７ミリモル）を加えて溶解し、第２段目の単量体水溶液を調製した。 Next, 128.8 g (1.44 mol) of an 80.5 mass% acrylic acid aqueous solution as a water-soluble ethylenically unsaturated monomer was placed in another beaker having an internal volume of 500 mL, and 27 mass while cooling from the outside. 159.0 g of a% aqueous sodium hydroxide solution was added dropwise to neutralize 75 mol%. Then, 0.090 g (0.333 mmol) of potassium persulfate as a water-soluble radical polymerization initiator and 0.0116 g (0.067 mmol) of ethylene glycol diglycidyl ether as an internal cross-linking agent were added and dissolved, and the second step was performed. A monomer aqueous solution of the above was prepared.
　撹拌機の回転数を１０００ｒｐｍとして撹拌しながら、上記フラスコ系内を４４℃に冷却した。その後、第２段目の水性液の全量を第１段目の重合スラリー液に添加して、系内を窒素で３０分間置換した。その後、再度フラスコを７０℃の水浴に浸漬して昇温し、重合反応を６０分間行って、含水ゲル重合体を得た。 The inside of the flask system was cooled to 44 ° C. while stirring at a stirring machine rotation speed of 1000 rpm. Then, the whole amount of the aqueous solution of the second stage was added to the polymerized slurry solution of the first stage, and the inside of the system was replaced with nitrogen for 30 minutes. Then, the flask was immersed in a water bath at 70 ° C. again to raise the temperature, and the polymerization reaction was carried out for 60 minutes to obtain a hydrogel polymer.
　その後、１２５℃に設定した油浴にフラスコを浸漬し、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、２６０．１ｇの水を系外へ抜き出した。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、８３℃で２時間保持した。 After that, the flask was immersed in an oil bath set at 125 ° C., and 260.1 g of water was extracted from the system while refluxing n-heptane by azeotropic distillation of n-heptane and water. Then, 4.42 g (0.507 mmol) of a 2% by mass ethylene glycol diglycidyl ether aqueous solution was added to the flask as a surface cross-linking agent, and the mixture was kept at 83 ° C. for 2 hours.
　その後、水及び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、重合体粒子（乾燥品）を得た。この重合体粒子を目開き８５０μｍの篩に通過させ、吸水性樹脂粒子を２２９．８ｇ得た。 Then, water and n-heptane were evaporated at 125 ° C. and dried to obtain polymer particles (dried product). The polymer particles were passed through a sieve having an opening of 850 μm to obtain 229.8 g of water-absorbent resin particles.
　上記操作を繰り返し、吸水性樹脂粒子（Ｃ）を５００ｇ以上入手した。吸水性樹脂粒子（Ｃ）の保水量は４３ｇ／ｇ、中位粒子径は７２μｍであった。 By repeating the above operation, 500 g or more of water-absorbent resin particles (C) were obtained. The water-absorbing resin particles (C) had a water retention amount of 43 g / g and a medium particle diameter of 72 μm.
（樹脂粒子組成物の作製）
　定着部材液を、エチレン－アクリル酸ナトリウム共重合体（住友精化株式会社、ザイクセンＮ）の２５％水分散エマルジョン１００．０ｇをイオン交換水１５０．０ｇで希釈したものに変更したこと、及び、吸水性樹脂粒子（Ａ）の代わりに吸水性樹脂粒子（Ｃ）を用いたこと以外は、実施例１と同様に行い、中位粒子径８６μｍの樹脂粒子組成物５０４．８ｇを得た。 (Preparation of resin particle composition)
The fixing member liquid was changed to 100.0 g of a 25% aqueous dispersion emulsion of an ethylene-sodium acrylate copolymer (Sumitomo Seika Co., Ltd., Zyxen N) diluted with 150.0 g of ion-exchanged water. The same procedure as in Example 1 was carried out except that the water-absorbent resin particles (C) were used instead of the water-absorbent resin particles (A), and 504.8 g of a resin particle composition having a medium particle diameter of 86 μm was obtained.
［比較例１］
　定着部材液を、ポリビニルアルコール（株式会社クラレ、クラレポバール３－８０）２５．０ｇをイオン交換水３３２．５ｇとエタノール１４２．５ｇとの混合液に溶解したものに変更したこと以外は、実施例１と同様に行い、中位粒子径３４５μｍの樹脂粒子組成物５０４．４ｇを得た。 [Comparative Example 1]
Examples except that the fixing member liquid was changed to a solution prepared by dissolving 25.0 g of polyvinyl alcohol (Kuraray Co., Ltd., Kuraray Poval 3-80) in a mixed solution of 332.5 g of ion-exchanged water and 142.5 g of ethanol. The same procedure as in No. 1 was carried out to obtain 504.4 g of a resin particle composition having a medium particle diameter of 345 μm.
［比較例２］
　定着部材液を、メタクリル酸メチル（富士フイルム和光純薬株式会社、メタクリル酸メチルポリマー）２５．０ｇをアセトン４７５．０ｇに溶解したものに変更したこと、流動層造粒機での温風温度及び乾燥温度を３０℃に変更したこと以外は、実施例１と同様に行い、中位粒子径３３９μｍの樹脂粒子組成物５０５．３ｇを得た。 [Comparative Example 2]
The fixing member liquid was changed to one in which 25.0 g of methyl methacrylate (Fujifilm Wako Pure Chemical Co., Ltd., methyl methacrylate polymer) was dissolved in 475.0 g of acetone. The same procedure as in Example 1 was carried out except that the drying temperature was changed to 30 ° C. to obtain 505.3 g of a resin particle composition having a medium particle diameter of 339 μm.
　得られた樹脂粒子組成物について、以下の項目で評価した。なお、特に断りのない限り、測定は温度２５±２℃、湿度５０±１０％の環境下で実施した。 The obtained resin particle composition was evaluated according to the following items. Unless otherwise specified, the measurements were carried out in an environment with a temperature of 25 ± 2 ° C. and a humidity of 50 ± 10%.
［ケーキング指数の測定］
　片面がシリコーンコーティングされた剥離紙（リンテック株式会社製、ＫＡ－４ＧシロＢＤ）を直径５０ｍｍの円形に切り取った。内径５２ｍｍの円形ステンレス製シャーレの中に、円形の剥離紙をシリコーンコーティングされた表面が上になるよう敷いた。該剥離紙の上に、粒径８５０μｍ以上の粒子をあらかじめ除いた樹脂粒子組成物２．０±０．００２ｇを均一に撒布した。該樹脂粒子組成物の上に、上記と同様の剥離紙を、シリコーンコーティングされた表面が樹脂粒子組成物と接するよう置き、外径５０ｍｍで質量２０ｇの円形ステンレス製シャーレ、及び直径４５ｍｍの円柱状の重り７８０ｇをこの順に重ね、測定サンプルを作製した。 [Measurement of caking index]
A release paper (KA-4G white BD manufactured by Lintec Corporation) coated with silicone on one side was cut into a circle having a diameter of 50 mm. A circular release paper was laid in a circular stainless steel petri dish with an inner diameter of 52 mm so that the silicone-coated surface was on top. 2.0 ± 0.002 g of a resin particle composition excluding particles having a particle size of 850 μm or more was uniformly sprinkled on the release paper. A release paper similar to the above is placed on the resin particle composition so that the silicone-coated surface is in contact with the resin particle composition, and a circular stainless steel chalet having an outer diameter of 50 mm and a mass of 20 g and a columnar diameter of 45 mm are placed. A measurement sample was prepared by stacking 780 g of the weights in this order.
　測定サンプルを内温８０℃に設定した熱風乾燥機の中に入れ、１時間静置した。測定サンプルを熱風乾燥機から取り出して室温まで放冷した。その後、測定サンプルから剥離紙とともに樹脂粒子組成物を取り出し、下部に受け皿を付した目開き８５０μｍの篩（内径２００ｍｍ）上で、剥離紙から樹脂粒子組成物を注意深く取り外し、樹脂粒子組成物の全量を該篩に載せた。該篩をロータップ式振盪機（飯田製作所社製、ふるい振盪機ロータップ型）を用いて５秒間振動させた後、篩上に残った樹脂粒子組成物の質量Ｗａ［ｇ］、篩を通過した樹脂粒子組成物の質量Ｗｂ［ｇ］をそれぞれ測定し、樹脂粒子組成物総量に対する篩上に残った樹脂粒子組成物量の割合としてのケーキング指数を、下記式から算出した。結果を表１に示す。
　ケーキング指数［％］＝［Ｗａ／（Ｗａ＋Ｗｂ）］×１００ The measurement sample was placed in a hot air dryer set to an internal temperature of 80 ° C. and allowed to stand for 1 hour. The measurement sample was taken out from the hot air dryer and allowed to cool to room temperature. Then, the resin particle composition is taken out from the measurement sample together with the release paper, and the resin particle composition is carefully removed from the release paper on a sieve (inner diameter 200 mm) having an opening of 850 μm with a saucer at the bottom, and the total amount of the resin particle composition is obtained. Was placed on the sieve. After vibrating the sieve for 5 seconds using a low-tap type shaker (sieving shaker low-tap type manufactured by Iida Seisakusho Co., Ltd.), the mass Wa [g] of the resin particle composition remaining on the sieve and the resin passed through the sieve. The mass Wb [g] of the particle composition was measured, and the caking index as the ratio of the amount of the resin particle composition remaining on the sieve to the total amount of the resin particle composition was calculated from the following formula. The results are shown in Table 1.
Caking index [%] = [Wa / (Wa + Wb)] x 100
［生理食塩水保水量の測定］
　吸水性樹脂粒子及び樹脂粒子組成物の生理食塩水の保水量を下記手順で測定した。まず、測定粒子を２．０±０．００２ｇ量り取った綿袋（メンブロード６０番、横１００ｍｍ×縦２００ｍｍ）を内容積５００ｍＬのビーカー内に設置した。測定粒子の入った綿袋内に生理食塩水５００ｇを、ママコができないように一度に注ぎ込んだ後、綿袋の上部を輪ゴムで縛り、３０分静置させることで測定粒子を膨潤させた。３０分経過後の綿袋を、遠心力が１６７Ｇとなるように設定した脱水機（株式会社コクサン製、品番：Ｈ－１２２）を用いて１分間脱水した後、脱水後の膨潤ゲルを含んだ綿袋の質量Ｗｃ［ｇ］を測定した。吸水性樹脂粒子または樹脂粒子組成物を添加せずに同様の操作を行い、綿袋の湿潤時の空質量Ｗｄ［ｇ］を測定し、下記式から吸水性樹脂粒子及び樹脂粒子組成物の生理食塩水の保水量を算出した。結果を表１に示す。
　保水量［ｇ／ｇ］＝（Ｗｃ－Ｗｄ）／２．０ [Measurement of saline retention]
The water retention amount of the water-absorbent resin particles and the physiological saline of the resin particle composition was measured by the following procedure. First, a cotton bag (Membrod No. 60, width 100 mm × length 200 mm) from which 2.0 ± 0.002 g of measurement particles were weighed was placed in a beaker having an internal volume of 500 mL. After pouring 500 g of physiological saline into a cotton bag containing the measurement particles at a time so that mamaco could not be formed, the upper part of the cotton bag was tied with a rubber band and allowed to stand for 30 minutes to swell the measurement particles. The cotton bag after 30 minutes was dehydrated for 1 minute using a dehydrator (manufactured by Kokusan Co., Ltd., product number: H-122) set to have a centrifugal force of 167 G, and then contained the swollen gel after dehydration. The mass Wc [g] of the cotton bag was measured. Perform the same operation without adding the water-absorbent resin particles or the resin particle composition, measure the empty mass Wd [g] when the cotton bag is wet, and use the following formula to measure the physiology of the water-absorbent resin particles and the resin particle composition. The amount of water retained in the saline solution was calculated. The results are shown in Table 1.
Water retention [g / g] = (Wc-Wd) /2.0
［中位粒子径の測定］
　樹脂粒子組成物の上述の中位粒子径は下記手順により測定した。すなわち、ＪＩＳ標準篩を上から、目開き６００μｍの篩、目開き５００μｍの篩、目開き４２５μｍの篩、目開き３００μｍの篩、目開き２５０μｍの篩、目開き１８０μｍの篩、目開き１５０μｍの篩、及び受け皿の順に組み合わせた。組み合わせた最上の篩に、樹脂粒子組成物５０ｇを入れ、ロータップ式振とう器を用いて１０分間振とうさせて分級した。分級後、各篩上に残った粒子の質量を全量に対する質量百分率として算出し粒度分布を求めた。この粒度分布に関して粒子径の大きい方から順に篩上を積算することにより、篩の目開きと篩上に残った粒子の質量百分率の積算値との関係を対数確率紙にプロットした。確率紙上のプロットを直線で結ぶことにより、積算質量百分率５０質量％に相当する粒子径を中位粒子径として得た。 [Measurement of medium particle size]
The above-mentioned medium particle size of the resin particle composition was measured by the following procedure. That is, from the top of the JIS standard sieve, a sieve with an opening of 600 μm, a sieve with an opening of 500 μm, a sieve with an opening of 425 μm, a sieve with an opening of 300 μm, a sieve with an opening of 250 μm, a sieve with an opening of 180 μm, and a sieve with an opening of 150 μm. , And the saucer in that order. 50 g of the resin particle composition was put into the combined best sieve and shaken for 10 minutes using a low-tap type shaker to classify. After classification, the mass of the particles remaining on each sieve was calculated as a mass percentage with respect to the total amount, and the particle size distribution was obtained. The relationship between the mesh size of the sieve and the integrated value of the mass percentage of the particles remaining on the sieve was plotted on a logarithmic probability paper by integrating the particles on the sieve in order from the one having the largest particle size with respect to this particle size distribution. By connecting the plots on the probability paper with a straight line, the particle size corresponding to the integrated mass percentage of 50% by mass was obtained as the medium particle size.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
　実施例では、一定以上のケーキング指数を有する樹脂粒子組成物が得られた。このような樹脂粒子組成物を吸収体作製時に加圧加熱して組み込むことにより、粒子が脱落しにくい吸収体を製造することが可能である。 In the examples, a resin particle composition having a caking index of a certain level or higher was obtained. By incorporating such a resin particle composition under pressure and heating at the time of producing the absorber, it is possible to produce an absorber in which the particles do not easily fall off.

Claims (5)

  1. 　吸水性樹脂粒子と定着部材層とを有し、
    　下記（１）～（５）の順に行われるケーキング試験後に、用いた目開き８５０μｍの篩上に粒子の少なくとも一部が残存する、樹脂粒子組成物。
    （１）内径５２ｍｍの円形ステンレス製シャーレの底に、直径５０ｍｍの円形剥離紙を敷き、該剥離紙の上に、粒径８５０μｍ未満の樹脂粒子組成物２．０ｇを散布する。
    （２）散布した樹脂粒子組成物の上に、直径５０ｍｍの円形剥離紙、外形５０ｍｍで質量２０ｇの円形ステンレス製シャーレ、及び直径４５ｍｍの円柱状重り７８０ｇをこの順に重ねることにより測定サンプルを得る。
    （３）測定サンプルを熱風乾燥機により８０℃で１時間乾燥させた後、室温まで放冷する。
    （４）放冷後の該剥離紙から樹脂粒子組成物を取り外して回収し、回収した樹脂粒子組成物の全量を目開き８５０μｍの篩上に載せる。
    （５）前記篩をロータップ式篩振盪機にて５秒間振盪した後に前記篩上に樹脂粒子組成物が残存するかを確認する。     It has water-absorbent resin particles and a fixing member layer,
    A resin particle composition in which at least a part of particles remains on the sieve having an opening of 850 μm used after the caking test performed in the order of (1) to (5) below.
    (1) A circular release paper having a diameter of 50 mm is laid on the bottom of a circular stainless steel petri dish having an inner diameter of 52 mm, and 2.0 g of a resin particle composition having a particle size of less than 850 μm is sprayed on the release paper.
    (2) A measurement sample is obtained by stacking a circular release paper having a diameter of 50 mm, a circular stainless steel petri dish having an outer diameter of 50 mm and a mass of 20 g, and a cylindrical weight having a diameter of 45 mm, 780 g, on the sprayed resin particle composition in this order.
    (3) The measurement sample is dried at 80 ° C. for 1 hour with a hot air dryer, and then allowed to cool to room temperature.
    (4) The resin particle composition is removed from the release paper after cooling and recovered, and the entire amount of the recovered resin particle composition is placed on a sieve having an opening of 850 μm.
    (5) After shaking the sieve with a low-tap type sieve shaker for 5 seconds, it is confirmed whether the resin particle composition remains on the sieve.
  2. 　前記ケーキング試験により測定される、下記式で示されるケーキング指数が２０％以上である、請求項１に記載の樹脂粒子組成物。
    　ケーキング指数（％）＝［目開き８５０μｍの篩上に残存した樹脂粒子組成物の質量／（目開き８５０μｍの篩上に残存した樹脂粒子組成物及び目開き８５０μｍの篩を通過した樹脂粒子組成物の合計質量）］×１００     The resin particle composition according to claim 1, wherein the caking index represented by the following formula, which is measured by the caking test, is 20% or more.
    Caking index (%) = [Mass of resin particle composition remaining on a sieve with an opening of 850 μm / (Resin particle composition remaining on a sieve with an opening of 850 μm and a resin particle composition passing through a sieve with an opening of 850 μm) Total mass)] x 100
  3. 　前記定着部材が、エチレン系重合体、ポリエーテル系重合体、ポリアミド系重合体、ポリウレタン系重合体、及びポリエステル系重合体からなる群から選ばれる少なくとも１種を含む、請求項１又は２に記載の樹脂粒子組成物。 The first or second claim, wherein the fixing member includes at least one selected from the group consisting of an ethylene-based polymer, a polyether-based polymer, a polyamide-based polymer, a polyurethane-based polymer, and a polyester-based polymer. Resin particle composition.
  4. 　前記定着部材の量が、前記吸水性樹脂粒子１００質量部に対して、０．０１～１０質量部である、請求項１～３のいずれか一項に記載の樹脂粒子組成物。 The resin particle composition according to any one of claims 1 to 3, wherein the amount of the fixing member is 0.01 to 10 parts by mass with respect to 100 parts by mass of the water-absorbent resin particles.
  5. 　生理食塩水保水量が３０ｇ／ｇ以上である、請求項１～４のいずれか一項に記載の樹脂粒子組成物。 The resin particle composition according to any one of claims 1 to 4, wherein the physiological saline water retention amount is 30 g / g or more.
PCT/JP2021/043855 2020-12-09 2021-11-30 Resin particle composition WO2022124137A1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
CN202180080826.1A CN116568761B (en) 2020-12-09 2021-11-30 Resin particle composition
JP2022568204A JPWO2022124137A1 (en) 2020-12-09 2021-11-30

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2020204039 2020-12-09
JP2020-204039 2020-12-09

Publications (1)

Publication Number Publication Date
WO2022124137A1 true WO2022124137A1 (en) 2022-06-16

Family

ID=81973927

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2021/043855 WO2022124137A1 (en) 2020-12-09 2021-11-30 Resin particle composition

Country Status (3)

Country Link
JP (1) JPWO2022124137A1 (en)
CN (1) CN116568761B (en)
WO (1) WO2022124137A1 (en)

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007229403A (en) * 2006-03-03 2007-09-13 Eco Life Nt Kenkyusho:Kk Water retaining sheet and manufacturing method
JP2012189346A (en) * 2011-03-09 2012-10-04 Tanaka Kikinzoku Kogyo Kk Absorption pad
JP2012218320A (en) * 2011-04-11 2012-11-12 Sumitomo Seika Chem Co Ltd Water absorption sheet construct
JP2013144445A (en) * 2005-05-13 2013-07-25 Asahi Kasei Chemicals Corp Method for producing absorbent composite material
WO2015178481A1 (en) * 2014-05-23 2015-11-26 Ｓｄｐグローバル株式会社 Water-absorbing resin particles, absorber comprising same, and absorbent article
JP2020097731A (en) * 2018-12-18 2020-06-25 Ｓｄｐグローバル株式会社 Water-absorbing resin particle, absorber containing the same, and water absorptive article

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
TW320647B (en) * 1993-02-24 1997-11-21
JP2000212458A (en) * 1999-01-25 2000-08-02 Sumitomo Seika Chem Co Ltd Highly water-absorptive resin particle
WO2014156289A1 (en) * 2013-03-27 2014-10-02 住友精化株式会社 Water-absorbent resin composition production method
JP6681494B1 (en) * 2019-01-30 2020-04-15 住友精化株式会社 Water absorbent resin particles

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2013144445A (en) * 2005-05-13 2013-07-25 Asahi Kasei Chemicals Corp Method for producing absorbent composite material
JP2007229403A (en) * 2006-03-03 2007-09-13 Eco Life Nt Kenkyusho:Kk Water retaining sheet and manufacturing method
JP2012189346A (en) * 2011-03-09 2012-10-04 Tanaka Kikinzoku Kogyo Kk Absorption pad
JP2012218320A (en) * 2011-04-11 2012-11-12 Sumitomo Seika Chem Co Ltd Water absorption sheet construct
WO2015178481A1 (en) * 2014-05-23 2015-11-26 Ｓｄｐグローバル株式会社 Water-absorbing resin particles, absorber comprising same, and absorbent article
JP2020097731A (en) * 2018-12-18 2020-06-25 Ｓｄｐグローバル株式会社 Water-absorbing resin particle, absorber containing the same, and water absorptive article

Also Published As

Publication number Publication date
CN116568761A (en) 2023-08-08
JPWO2022124137A1 (en) 2022-06-16
CN116568761B (en) 2024-08-13

Similar Documents

Publication Publication Date Title
CN110446726B (en) Water-absorbent resin particles
WO2021117782A1 (en) Coated resin particle and method for producing coated resin particle
JP6126655B2 (en) Method for producing water absorbent resin particles
JP6275107B2 (en) Water absorbent resin
EP2607383B1 (en) Water-absorbing resin
JP5591448B2 (en) Water absorbing agent and method for producing the same
EP2692741B1 (en) Process for producing water-absorbing resin
JP2005501960A (en) Superabsorbent hydrogel with specific particle size distribution
JPWO2007123188A1 (en) Method for producing water absorbent resin particles, and water absorbent resin particles obtained thereby
WO2002059214A1 (en) Water absorbing agent and method for production thereof, and water absorbing article
EP3604359B1 (en) Water-absorbent resin particles
EP2752430B1 (en) Method for producing water-absorbent resin, and water-absorbent resin obtained by same
JP2016121297A (en) Water absorptive resin composition
TW200840827A (en) Process for producing mechanically stable water-absorbing polymer particles
JP5927289B2 (en) Method for producing water absorbent resin particles
JP2016094625A (en) Manufacturing method of water absorbing polymer particle
EP3741783A1 (en) Water-absorbent resin
WO2022124137A1 (en) Resin particle composition
JP7291686B2 (en) Water-absorbing resin particles and method for producing the same
EP3896116A1 (en) Water-absorbent resin particles
WO2023100478A1 (en) Method for producing coated resin particle, and coated resin particle
WO2023100479A1 (en) Water absorbent resin particles and absorbent
WO2022239628A1 (en) Poly(meth)acrylic acid (salt)-based water-absorbing resin, and absorbent body
JP2022185314A (en) Water absorbent resin composition and its manufacturing method as well as manufacturing method of absorber
TW202330098A (en) Coated resin particles, water-absorbing resin composition, and absorbent body

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 21903241

Country of ref document: EP

Kind code of ref document: A1

ENP Entry into the national phase

Ref document number: 2022568204

Country of ref document: JP

Kind code of ref document: A

WWE Wipo information: entry into national phase

Ref document number: 202180080826.1

Country of ref document: CN

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 21903241

Country of ref document: EP

Kind code of ref document: A1