[go: up one dir, main page]

WO2021039714A1 - Article absorbant et feuille auxiliaire - Google Patents

Article absorbant et feuille auxiliaire Download PDF

Info

Publication number
WO2021039714A1
WO2021039714A1 PCT/JP2020/031838 JP2020031838W WO2021039714A1 WO 2021039714 A1 WO2021039714 A1 WO 2021039714A1 JP 2020031838 W JP2020031838 W JP 2020031838W WO 2021039714 A1 WO2021039714 A1 WO 2021039714A1
Authority
WO
WIPO (PCT)
Prior art keywords
water
resin particles
absorbent resin
liquid
sheet
Prior art date
Application number
PCT/JP2020/031838
Other languages
English (en)
Japanese (ja)
Inventor
海紗生 谷口
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 KR1020227008321A priority Critical patent/KR20220050917A/ko
Priority to JP2021542886A priority patent/JP7457718B2/ja
Priority to CN202080059123.6A priority patent/CN114269310B/zh
Publication of WO2021039714A1 publication Critical patent/WO2021039714A1/fr

Links

Images

Classifications

    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F13/00—Bandages or dressings; Absorbent pads
    • A61F13/15—Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators
    • A61F13/45—Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators characterised by the shape
    • A61F13/49—Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators characterised by the shape specially adapted to be worn around the waist, e.g. diapers, nappies
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F13/00—Bandages or dressings; Absorbent pads
    • A61F13/15—Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators
    • A61F13/53—Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators characterised by the absorbing medium
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F13/00—Bandages or dressings; Absorbent pads
    • A61F13/15—Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators
    • A61F13/53—Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators characterised by the absorbing medium
    • A61F13/534—Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators characterised by the absorbing medium having an inhomogeneous composition through the thickness of the pad
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F13/00—Bandages or dressings; Absorbent pads
    • A61F13/15—Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators
    • A61F13/84—Accessories, not otherwise provided for, for absorbent pads
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F13/00—Bandages or dressings; Absorbent pads
    • A61F13/15—Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators
    • A61F2013/15008—Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators characterized by the use
    • A61F2013/15146—Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators characterized by the use for urine collection

Definitions

  • the present invention relates to an absorbent article and an auxiliary sheet.
  • Absorbents containing water-absorbent resin particles are generally used as absorbent articles for absorbing water-based liquids such as urine.
  • water-absorbent sheet structure disclosed in Patent Document 1 below water-absorbent resin particles having a physiological saline water absorption rate within a predetermined range are used in the liquid-absorbent layer.
  • one aspect of the present invention is to provide an absorbent article in which liquid leakage at the initial stage of liquid absorption is suppressed.
  • Another aspect of the present invention is to provide an auxiliary sheet capable of suppressing liquid leakage in the initial stage of liquid absorption in an absorbent article.
  • One aspect of the present invention includes a water absorbing core, an auxiliary sheet for assisting liquid absorption by the water absorbing core, a liquid impermeable sheet and a liquid permeable sheet, and includes a liquid impermeable sheet, an auxiliary sheet, a water absorbing core and a liquid permeable sheet.
  • the auxiliary sheet includes a resin layer containing water-absorbent resin particles, and the following steps (1), (2), (3), (4) and (5) are included in this order.
  • the measured dry powder passing liquid absorption rate of the water-absorbent resin particles is 0.25 or more and 1.0 or less.
  • 0.2 g of water-absorbent resin particles are uniformly sprayed over the entire bottom surface of a cylindrical container having an inner diameter of 60 mm having a mesh-like bottom, and the total amount of the container and the water-absorbent resin particles sprayed in the container.
  • the mass Wb (g) is measured.
  • 20 mL of artificial urine having a liquid temperature of 25 ° C. is injected into the container on which the water-absorbent resin particles are sprayed at a constant rate of 8 mL / sec, and at least a part of the artificial urine is absorbed by the water-absorbent resin particles to make the container.
  • a swelling gel is formed within.
  • the dry powder passing liquid absorption amount (g) is determined from Wa (g) -Wb (g).
  • the dry powder passage liquid absorption rate (g / g) is obtained as the ratio of the dry powder passage liquid absorption amount (g) to the artificial urine saturated liquid absorption amount (g) of 0.2 g of the water-absorbent resin particles.
  • an auxiliary sheet capable of suppressing liquid leakage in the initial stage of liquid absorption in an absorbent article.
  • 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.
  • the absorbent article according to the embodiment includes a water absorbing core, an auxiliary sheet for assisting liquid absorption by the water absorbing core, a liquid impermeable sheet, and a liquid permeable sheet.
  • the liquid impermeable sheet, the auxiliary sheet, the water absorbing core and the liquid permeable sheet are arranged in this order. That is, the auxiliary sheet is arranged so as to be in contact with the surface of the absorbent core provided with the water absorbing core, which is opposite to the side on which the liquid to be absorbed is invaded.
  • the auxiliary sheet is used in an absorbent article provided with a water absorbing core to assist the liquid absorption of the water absorbing core.
  • the auxiliary sheet includes a resin layer containing water-absorbent resin particles, and is measured by a method including the following steps (1), (2), (3), (4) and (5) in this order.
  • the dry powder water absorption rate of the resin particles is 0.25 or more and 1.0 or less.
  • (1) 0.2 g of water-absorbent resin particles are uniformly sprayed over the entire bottom surface of a cylindrical container having an inner diameter of 60 mm having a mesh-like bottom, and the total amount of the container and the water-absorbent resin particles sprayed in the container.
  • the mass Wb (g) is measured.
  • the dry powder passing liquid absorption amount (g) is determined from Wa (g) -Wb (g).
  • the dry powder passage liquid absorption rate (g / g) is obtained as the ratio of the dry powder passage liquid absorption amount (g) to the artificial urine saturated liquid absorption amount (g) of 0.2 g of the water-absorbent resin particles.
  • the artificial urine sodium chloride (NaCl) 100.0 g, calcium chloride dihydrate (CaCl 2 ⁇ H 2 O) 3.0g, magnesium chloride hexahydrate (MgCl 2 ⁇ 6H 2 O) It is an aqueous solution prepared from 6.0 g, 25.0 g of Triton X-100 (1%), 0.25 g of Edible Blue No. 1, and 9865.75 g of water.
  • the artificial urine saturated liquid absorption amount is an index showing the saturated liquid absorption amount of artificial urine in a predetermined amount of water-absorbent resin particles, and the dry powder passing liquid absorption amount is a short time after contact between the water-absorbent resin particles and artificial urine. It is an index that reflects the amount of liquid absorbed during (initial).
  • the high dry powder passage liquid absorption rate which is the ratio of the dry powder passage liquid absorption amount to the artificial urine saturated liquid absorption amount, means that the liquid permeability of the water-absorbent resin particles in a short time (initial) after contact with artificial urine is high. It is thought to mean high.
  • the auxiliary sheet provided with the resin layer containing the water-absorbent resin particles having high liquid permeability at the initial stage instantly absorbs the liquid that could not be absorbed by the water-absorbing core, so that the liquid at the initial stage of liquid absorption in the absorbent article It is presumed that leakage will be suppressed.
  • the lower limit of the liquid absorption rate of dry powder is 0.25 or more, and from the viewpoint of further excellent effect of suppressing liquid leakage in the initial stage of liquid absorption, 0.30 or more, 0.35 or more, 0.40 or more, 0. It may be 45 or more, 0.50 or more, 0.55 or more, 0.60 or more, 0.65 or more, 0.70 or more, 0.75 or more, 0.80 or more, or 0.85 or more.
  • the upper limit of the dry powder passing liquid absorption rate is 1.0 or less, and may be 0.95 or less, or 0.90 or less.
  • the artificial urine saturated liquid absorption amount of 0.2 g of the water-absorbent resin particles shows the same amount of saturated absorption of 0.2 g of the water-absorbent resin particles as the amount used for measuring the dry powder passage liquid absorption rate, and therefore is usually the same amount.
  • the upper limit of the dry powder liquid absorption rate is usually 1.0 or less.
  • the amount of dry powder flowing through is, for example, 2.7 g or more, 3.0 g or more, 4.0 g or more, 5.0 g or more, 6.0 g or more, 7.0 g or more, 8.0 g or more, or 9.0 g or more. It may be 15.0 g or less, 12.0 g or less, or 10.0 g or less.
  • a specific method for measuring the amount of dry powder flowing through the liquid is as described in Examples described later.
  • the artificial urine saturated liquid absorption amount of 0.2 g of the water-absorbent resin particles is calculated by a method including the following steps (a), (b), (c), (d) and (e) in this order.
  • (A) Put 500 g of artificial urine into a 500 mL beaker.
  • (B) 2.0 g of water-absorbent resin particles are charged into the beaker into which the artificial urine is charged while stirring the artificial urine at 600 rpm using a magnetic stirrer bar (8 mm ⁇ ⁇ 30 mm, without ring).
  • C The artificial urine and the water-absorbent resin particles are stirred at 600 rpm for 60 minutes after the water-absorbent resin particles are added to form a swollen gel.
  • the artificial urine saturated liquid absorption amount of 0.2 g of the water-absorbent resin particles is, for example, 7.0 or more, 8.0 or more, 9.0 or more, or 10.0 from the viewpoint of the water absorption characteristics of the water-absorbent resin particles. It may be 20.0 or less, 15.0 or less, 13.0 or less, or 11.0 or less.
  • a specific method for measuring the artificial urine saturated liquid absorption amount of 0.2 g of the water-absorbent resin particles is as described in Examples described later.
  • the shape of the water-absorbent resin particles may be, for example, substantially spherical, crushed or granular, and particles having agglomerated primary particles having these shapes may be formed.
  • the medium particle size of the water-absorbent resin particles may be 45 to 850 ⁇ m, 75 to 700 ⁇ m, 100 to 600 ⁇ m, or 200 to 600 ⁇ m.
  • the water-absorbent resin particles may have a desired particle size distribution at the time of being obtained by the production method described later, but the particle size distribution may be adjusted by performing an operation such as particle size adjustment using classification with a sieve. Good.
  • the water-absorbent resin particles can include, for example, a crosslinked polymer formed by polymerizing a monomer containing an ethylenically unsaturated monomer.
  • the crosslinked polymer has a monomer unit derived from an ethylenically unsaturated monomer.
  • the water-absorbent resin particles can be produced by a method including a step of polymerizing a monomer containing an ethylenically unsaturated monomer.
  • the polymerization method include a reverse phase suspension polymerization method, an aqueous solution polymerization method, a bulk polymerization method, and a precipitation polymerization method. From the viewpoint of ensuring good water absorption characteristics of the obtained water-absorbent resin particles and facilitating control of the polymerization reaction, a reverse phase suspension polymerization method or an aqueous solution polymerization method may be applied. In the following, a reverse phase suspension polymerization method will be described as an example as a method for polymerizing an ethylenically unsaturated monomer.
  • the ethylenically unsaturated monomer may be water-soluble.
  • water-soluble ethylenically unsaturated monomers include (meth) acrylic acid and its salts, 2- (meth) acrylamide-2-methylpropanesulfonic acid and its salts, (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.
  • Functional groups such as the carboxyl group and amino group of the above-mentioned monomers can function as functional groups capable of cross-linking in the surface cross-linking step described later.
  • 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.
  • the ethylenically unsaturated monomer may contain at least one compound selected from the group consisting of (meth) acrylic acid and salts thereof.
  • the ethylenically unsaturated monomer can be used in the polymerization reaction as an aqueous solution.
  • concentration of the ethylenically unsaturated monomer in the aqueous solution containing the ethylenically unsaturated monomer (hereinafter, simply referred to as "monomer aqueous solution") is 20% by mass or more and the saturation concentration or less, 25 to 70% by mass, or 30. It may be up to 55% by mass.
  • Examples of the water used in the aqueous solution include tap water, distilled water, ion-exchanged water and the like.
  • a monomer other than the above-mentioned ethylenically unsaturated monomer may be used.
  • Such a monomer can be used, for example, by being mixed 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.
  • the acid group may be neutralized with an alkaline neutralizer and then the monomer solution may be used in the polymerization reaction.
  • the degree of neutralization of an ethylenically unsaturated monomer by an alkaline neutralizing agent increases the osmotic pressure of the obtained water-absorbent resin particles and further enhances the water absorption characteristics (water absorption amount, etc.). It may be 10-100 mol%, 50-90 mol%, or 60-80 mol% of the acidic group in the body.
  • the alkaline neutralizer include alkali metal salts such as sodium hydroxide, sodium carbonate, sodium hydrogen carbonate, potassium hydroxide and potassium carbonate; ammonia and the like.
  • the alkaline neutralizer may be used alone or in combination of two or more.
  • the alkaline neutralizer may be used in the form of an aqueous solution to simplify the neutralization operation.
  • Neutralization of the acid group of the ethylenically unsaturated monomer can be performed, for example, by adding an aqueous solution of sodium hydroxide, potassium hydroxide or the like to the above-mentioned monomer aqueous solution and mixing them.
  • the monomer aqueous solution is dispersed in a hydrocarbon dispersion medium in the presence of a surfactant, and the ethylenically unsaturated monomer is polymerized using a radical polymerization initiator or the like.
  • a radical polymerization initiator a water-soluble radical polymerization initiator can be used.
  • surfactant examples include nonionic surfactants and anionic surfactants.
  • nonionic surfactant sorbitan fatty acid ester and (poly) glycerin fatty acid ester (“(poly)” means both with and without the prefix of “poly”. The same shall apply hereinafter.
  • Sucrose fatty acid ester polyoxyethylene sorbitan fatty acid ester, polyoxyethylene glycerin fatty acid ester, sorbitol fatty acid ester, polyoxyethylene sorbitol fatty acid ester, polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene himashi
  • oil polyoxyethylene cured castor oil, alkylallyl formaldehyde condensed polyoxyethylene ether, polyoxyethylene polyoxypropylene block copolymer, polyoxyethylene polyoxypropyl alkyl ether, polyethylene glycol fatty acid ester and the like.
  • anionic surfactants include fatty acid salts, alkylbenzene sulfonates, alkylmethyl taurates, polyoxyethylene alkylphenyl ether sulfates, polyoxyethylene alkyl ether sulfonates, and phosphoric acid esters of polyoxyethylene alkyl ethers. , And the phosphate ester of polyoxyethylene alkyl allyl ether and the like.
  • the surfactant may be used alone or in combination of two or more.
  • the surfactant is a sorbitan fatty acid ester. It may contain at least one compound selected from the group consisting of polyglycerin fatty acid ester and sucrose fatty acid ester. From the viewpoint of easily improving the water absorption characteristics of the obtained water-absorbent resin particles, a sorbitan fatty acid ester and / or a sucrose fatty acid ester (for example, sucrose stearic acid ester) can be used as the surfactant. These surfactants may be used alone or in combination of two or more.
  • the amount of the surfactant may be 0.05 to 10 parts by mass, 0.08 to 5 parts by mass, or 0.1 to 3 parts by mass with respect to 100 parts by mass of the monomer aqueous solution.
  • a polymer-based dispersant may be used in combination with the above-mentioned surfactant.
  • the polymer dispersant include maleic anhydride-modified polyethylene, maleic anhydride-modified polypropylene, maleic anhydride-modified ethylene / propylene copolymer, maleic anhydride-modified EPDM (ethylene / propylene / diene / terpolymer), and maleic anhydride.
  • the polymer-based dispersant may be used alone or in combination of two or more.
  • the polymer-based dispersant includes maleic anhydride-modified polyethylene, maleic anhydride-modified polypropylene, maleic anhydride-modified ethylene / propylene copolymer, and maleic anhydride / ethylene copolymer.
  • Maleic anhydride / propylene copolymer, maleic anhydride / ethylene / propylene copolymer, polyethylene, polypropylene, ethylene / propylene copolymer, oxidized polyethylene, oxidized polypropylene, and oxidized ethylene / propylene copolymer It may be at least one selected from the group consisting of.
  • the amount of the polymer-based dispersant may be 0.05 to 10 parts by mass, 0.08 to 5 parts by mass, or 0.1 to 3 parts by mass with respect to 100 parts by mass of the monomer aqueous solution.
  • the hydrocarbon dispersion medium may contain at least one compound selected from the group consisting of chain aliphatic hydrocarbons having 6 to 8 carbon atoms and alicyclic hydrocarbons having 6 to 8 carbon atoms.
  • Hydrocarbon dispersion media include chain aliphatic hydrocarbons such as n-hexane, n-heptane, 2-methylhexane, 3-methylhexane, 2,3-dimethylpentane, 3-ethylpentane, and n-octane; cyclohexane.
  • the hydrocarbon dispersion medium may be used alone or in combination of two or more.
  • the hydrocarbon dispersion medium may contain at least one selected from the group consisting of n-heptane and cyclohexane.
  • the mixture of the above-mentioned hydrocarbon dispersion medium for example, commercially available ExxonHeptane (manufactured by ExxonMobil: containing 75 to 85% of n-heptane and isomeric hydrocarbons) is used. You may.
  • the amount of the hydrocarbon dispersion medium is 30 to 1000 parts by mass, 40 to 500 parts by mass, or 50 parts by mass with respect to 100 parts by mass of the monomer aqueous solution from the viewpoint of appropriately removing the heat of polymerization and easily controlling the polymerization temperature. It may be up to 300 parts by mass. When the amount of the hydrocarbon dispersion medium is 30 parts by mass or more, the polymerization temperature tends to be easily controlled. When the amount of the hydrocarbon dispersion medium is 1000 parts by mass or less, the productivity of polymerization tends to be improved, which is economical.
  • the radical polymerization initiator may be water-soluble.
  • water-soluble radical polymerization initiators are persulfates such as potassium persulfate, ammonium persulfate, and sodium persulfate; methyl ethyl ketone peroxide, methyl isobutyl ketone peroxide, di-t-butyl peroxide, and t-butyl cumylper.
  • Peroxides such as oxides, t-butylperoxyacetate, t-butylperoxyisobutyrate, t-butylperoxypivalate, hydrogen peroxide; 2,2'-azobis (2-amidinopropane) dihydrochloride , 2,2'-azobis [2- (N-phenylamidino) propane] dihydrochloride, 2,2'-azobis [2- (N-allylamidino) propane] dihydrochloride, 2,2'-azobis [ 2- (2-Imidazolin-2-yl) propane] 2 hydrochloride, 2,2'-azobis ⁇ 2- [1- (2-hydroxyethyl) -2-imidazolin-2-yl] propane ⁇ 2 hydrochloride, 2,2'-azobis ⁇ 2-methyl-N- [1,1-bis (hydroxymethyl) -2-hydroxyethyl] propionamide ⁇ , 2,2'-azobis [2-methyl-N- (2-hydroxy) Ethyl) -propion
  • the radical polymerization initiator may be used alone or in combination of two or more.
  • the radical polymerization initiators are potassium persulfate, ammonium persulfate, sodium persulfate, 2,2'-azobis (2-amidinopropane) dihydrochloride, 2,2'-azobis [2- (2-imidazolin-2-yl). ) Propane] 2 hydrochloride and 2,2'-azobis ⁇ 2- [1- (2-hydroxyethyl) -2-imidazolin-2-yl] propane ⁇ 2 hydrochloride at least selected from the group. There may be.
  • the amount of the radical polymerization initiator may be 0.00005 to 0.01 mol per 1 mol of the ethylenically unsaturated monomer.
  • the amount of the radical polymerization initiator used is 0.00005 mol or more, the polymerization reaction does not require a long time and is efficient.
  • the amount of the radical polymerization initiator is 0.01 mol or less, it is easy to suppress the occurrence of a rapid polymerization reaction.
  • the exemplified radical polymerization initiator can also be used as a redox polymerization initiator in combination with a reducing agent such as sodium sulfite, sodium hydrogen sulfite, ferrous sulfate, and L-ascorbic acid.
  • a reducing agent such as sodium sulfite, sodium hydrogen sulfite, ferrous sulfate, and L-ascorbic acid.
  • the aqueous monomer solution may contain a chain transfer agent.
  • chain transfer agent include hypophosphates, thiols, thiolic acids, secondary alcohols, amines and the like.
  • the monomer aqueous solution used for the polymerization may contain a thickener.
  • the thickener include hydroxyethyl cellulose, hydroxypropyl cellulose, methyl cellulose, carboxymethyl cellulose, polyacrylic acid, polyethylene glycol, polyacrylamide, polyethyleneimine, dextrin, sodium alginate, polyvinyl alcohol, polyvinylpyrrolidone, polyethylene oxide and the like. If the stirring speed at the time of polymerization is the same, the higher the viscosity of the aqueous monomer solution, the larger the medium particle size of the obtained particles tends to be.
  • Cross-linking by self-cross-linking may occur during polymerization, but cross-linking may be further 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 of the water-absorbent resin particles.
  • the internal cross-linking agent is usually added to the reaction solution during the polymerization reaction.
  • the internal cross-linking agent examples include di or tri (meth) acrylic acid esters of polyols such as ethylene glycol, propylene glycol, trimethylpropane, glycerin, polyoxyethylene glycol, polyoxypropylene glycol, and polyglycerin; Unsaturated polyesters obtained by reacting polyols with unsaturated acids (maleic acid, fumaric acid, etc.); bis (meth) acrylamides such as N, N'-methylenebis (meth) acrylamide; polyepoxides and (meth) Di or tri (meth) acrylic acid esters obtained by reacting with acrylic acid; di (meth) obtained by reacting polyisocyanate (tolylene diisocyanate, hexamethylene diisocyanate, etc.) with hydroxyethyl (meth) acrylate.
  • polyols such as ethylene glycol, propylene glycol, trimethylpropane, glycerin, polyoxyethylene glycol, polyoxypropy
  • Acrylic acid carbamil esters compounds having two or more polymerizable unsaturated groups, such as allylated starch, allylated cellulose, diallyl phthalate, N, N', N "-triallyl isocyanurate, divinylbenzene; Poly such as (poly) ethylene glycol diglycidyl ether, (poly) propylene glycol diglycidyl ether, (poly) glycerin diglycidyl ether, (poly) glycerin triglycidyl ether, (poly) propylene glycol polyglycidyl ether, polyglycerol polyglycidyl ether, etc.
  • Poly such as (poly) ethylene glycol diglycidyl ether, (poly) propylene glycol diglycidyl ether, (poly) glycerin diglycidyl ether, (poly) glycerin triglycidyl ether, (poly) propy
  • Glyceridyl compound such as epichlorohydrin, epibromhydrin, ⁇ -methylepichlorohydrin; 2 reactive functional groups such as isocyanate compound (2,4-tolylene diisocyanate, hexamethylene diisocyanate, etc.) Examples thereof include compounds having more than one.
  • the internal cross-linking agent may be used alone or in combination of two or more.
  • the internal cross-linking agent may be a polyglycidyl compound or diglycidyl. It may be an ether compound.
  • the internal cross-linking agent comprises at least one selected from the group consisting of (poly) ethylene glycol diglycidyl ether, (poly) propylene glycol diglycidyl ether, and (poly) glycerin diglycidyl ether. It may be.
  • the amount of the internal cross-linking agent is not ethylenious from the viewpoint that the water-soluble property is suppressed by appropriately cross-linking the polymer obtained by the polymerization of the above-mentioned monomer aqueous solution, and a sufficient water absorption amount can be easily obtained. It may be 0 mmol or more, 0.01 mmol or more, 0.015 mmol or more, 0.020 mmol or more, or 0.1 mol or less, per 1 mol of saturated monomer.
  • Reverse-phase suspension polymerization can be carried out in an aqueous system in oil by heating with stirring in a state where the phases are mixed.
  • a monomer aqueous solution containing an ethylenically unsaturated monomer is used as a hydrocarbon dispersion medium in the presence of a surfactant (and, if necessary, a polymer-based dispersant). Disperse in.
  • a surfactant and, if necessary, a polymer-based dispersant.
  • the timing of adding the surfactant, the polymer-based dispersant, etc. may be either before or after the addition of the monomer aqueous solution.
  • the monomer aqueous solution is dispersed in the hydrocarbon dispersion medium in which the polymer-based dispersant is dispersed, and then the surfactant is further dispersed. It may be allowed to carry out polymerization.
  • Reverse phase suspension polymerization can be carried out in one stage or in multiple stages of two or more stages. Reversed phase suspension polymerization may be carried out in two or three stages from the viewpoint of increasing productivity.
  • an ethylenically unsaturated monomer is added to the reaction mixture obtained in the first step polymerization reaction after the first step reverse phase suspension polymerization is carried out. It may be added and mixed, and the reverse phase suspension polymerization of the second and subsequent steps may be carried out in the same manner as in the first step.
  • the above-mentioned radical polymerization initiator is used in the reverse phase suspension polymerization in each stage of the second and subsequent stages.
  • the ethylenically unsaturated monomer to be added Based on the amount of the ethylenically unsaturated monomer to be added, it may be added within the range of the molar ratio of each component to the above-mentioned ethylenically unsaturated monomer to carry out reverse phase suspension polymerization.
  • an internal cross-linking agent In the reverse phase suspension polymerization in each stage after the second stage, an internal cross-linking agent may be used if necessary.
  • an internal cross-linking agent When an internal cross-linking agent is used, it is added within the range of the molar ratio of each component to the above-mentioned ethylenically unsaturated monomer based on the amount of the ethylenically unsaturated monomer provided in each stage, and the suspension is reversed. Muddy polymerization may be carried out.
  • the temperature of the polymerization reaction varies depending on the radical polymerization initiator used, but by advancing the polymerization rapidly and shortening the polymerization time, the efficiency is improved and the heat of polymerization is easily removed to carry out the reaction smoothly. From the viewpoint, it may be 20 to 150 ° C. or 40 to 120 ° C.
  • the reaction time is usually 0.5-4 hours.
  • the completion of the polymerization reaction can be confirmed, for example, by stopping the temperature rise in the reaction system. As a result, the polymer of the ethylenically unsaturated monomer is usually obtained in the state of a hydrogel-like polymer.
  • cross-linking may be performed after polymerization by adding a cross-linking agent to the obtained hydrogel polymer and heating it.
  • a cross-linking agent to the obtained hydrogel polymer and heating it.
  • cross-linking agent for performing post-polymerization cross-linking examples include polyols such as ethylene glycol, propylene glycol, 1,4-butanediol, trimethylolpropane, glycerin, polyoxyethylene glycol, polyoxypropylene glycol, and polyglycerin; Compounds having two or more epoxy groups such as (poly) ethylene glycol diglycidyl ether, (poly) propylene glycol diglycidyl ether, and (poly) glycerin diglycidyl ether; epichlorohydrin, epibromhydrin, ⁇ -methylepicrolhydrin, etc.
  • polyols such as ethylene glycol, propylene glycol, 1,4-butanediol, trimethylolpropane
  • glycerin polyoxyethylene glycol, polyoxypropylene glycol, and polyglycerin
  • Compounds having two or more epoxy groups such as (poly) ethylene glycol
  • Haloepoxide compounds compounds having two or more isocyanate groups such as 2,4-tolylene diisocyanate and hexamethylene diisocyanate; oxazoline compounds such as 1,2-ethylenebisoxazoline; carbonate compounds such as ethylenecarbonate; bis [N , N-di ( ⁇ -hydroxyethyl)] hydroxyalkylamide compounds such as adipamide can be mentioned.
  • Cross-linking agents for post-polymerization cross-linking are (poly) ethylene glycol diglycidyl ether, (poly) glycerin diglycidyl ether, (poly) glycerin triglycidyl ether, (poly) propylene glycol polyglycidyl ether, and polyglycerol polyglycidyl ether. It may be a polyglycidyl compound such as. These cross-linking agents may be used alone or in combination of two or more.
  • the amount of the cross-linking agent used for post-polymerization cross-linking is 1 mol of the water-soluble ethylenically unsaturated monomer from the viewpoint of appropriately cross-linking the obtained hydrogel-like polymer to exhibit suitable water absorption characteristics. It may be 0 to 0.03 mol, 0 to 0.01 mol, or 0.00001 to 0.005 mol.
  • the cross-linking agent for post-polymerization cross-linking is added to the reaction solution after the polymerization reaction of the ethylenically unsaturated monomer.
  • a cross-linking agent for post-polymerization cross-linking may be added after the multi-stage polymerization.
  • the cross-linking agent for post-polymerization cross-linking is , From the viewpoint of water content (described later), it may be added in the region of [water content immediately after polymerization ⁇ 3% by mass].
  • drying to remove water gives polymer particles containing a polymer of ethylenically unsaturated monomers.
  • the drying method include (a) a method of removing water by azeotropic distillation in a state where the hydrogel polymer is dispersed in a hydrocarbon dispersion medium, and (b) a method of taking out the hydrogel polymer by decantation and reducing the pressure. Examples thereof include a method of drying, (c) a method of filtering the hydrogel polymer by a filter and drying under reduced pressure.
  • the particle size of the water-absorbent resin particles can be adjusted by adjusting the rotation speed of the stirrer during the polymerization reaction, or by adding a flocculant into the system after the polymerization reaction or in the early stage of drying. By adding a flocculant, the particle size of the obtained water-absorbent resin particles can be increased.
  • an inorganic flocculant can be used as the flocculant.
  • the inorganic flocculant for example, powdered inorganic flocculant
  • the aggregating agent may be at least one selected from the group consisting of silica, aluminum oxide, talc and kaolin.
  • a coagulant is previously dispersed in a hydrocarbon dispersion medium of the same type as that used in the polymerization or water, and then this is placed in a hydrocarbon dispersion medium containing a hydrogel polymer under stirring. May be mixed with.
  • the amount of the flocculant is 0.001 to 1 part by mass, 0.005 to 0.5 part by mass, or 0.01 to 0.2 with respect to 100 parts by mass of the ethylenically unsaturated monomer used for the polymerization. It may be a mass part. When the amount of the flocculant is within these ranges, it is easy to obtain water-absorbent resin particles having a desired particle size distribution.
  • the polymerization reaction can be carried out using various stirrers having stirring blades.
  • a flat plate blade a lattice blade, a paddle blade, a propeller blade, an anchor blade, a turbine blade, a Faudler blade, a ribbon blade, a full zone blade, a max blend blade and the like can be used.
  • the flat plate blade has a shaft (stirring shaft) and a flat plate portion (stirring portion) arranged around the shaft. Further, the flat plate portion may have a slit or the like.
  • the water content of the surface-crosslinked hydrogel polymer may be 5 to 50% by mass, 10 to 40% by mass, or 15 to 35% by mass.
  • the amount of water in the hydrogel polymer calculated by adding the amount of water used as needed.
  • Ws The amount of solids calculated from the amount of materials such as ethylenically unsaturated monomers, cross-linking agents, and initiators that make up the hydrogel polymer.
  • cross-linking agents include polyols such as ethylene glycol, propylene glycol, 1,4-butanediol, trimethylolpropane, glycerin, polyoxyethylene glycol, polyoxypropylene glycol, and polyglycerin; (poly) ethylene glycol diglycidyl.
  • Polyglycidyl compounds such as ether, (poly) glycerin diglycidyl ether, (poly) glycerin triglycidyl ether, trimethylpropan triglycidyl ether (poly) propylene glycol polyglycidyl ether, (poly) glycerol polyglycidyl ether; epichlorohydrin , Epibrom hydrin, ⁇ -methyl epichlorohydrin and other haloepoxy compounds; 2,4-tolylene diisocyanate, hexamethylene diisocyanate and other isocyanate compounds; 3-methyl-3-oxetane methanol, 3-ethyl-3-oxetane Oxetane compounds such as methanol, 3-butyl-3-oxetane methanol, 3-methyl-3-oxetane ethanol, 3-ethyl-3-oxetane ethanol, 3-butyl-3-ox
  • the surface cross-linking agent may be used alone or in combination of two or more.
  • the surface cross-linking agent may be a polyglycidyl compound, and may be (poly) ethylene glycol diglycidyl ether, (poly) glycerin diglycidyl ether, (poly) glycerin triglycidyl ether, (poly) propylene glycol polyglycidyl ether, and It may contain at least one selected from the group consisting of polyglycerol polyglycidyl ether.
  • the amount of the surface cross-linking agent is 0.00001 to 0.02 mol, 0.00005 to 0.01 mol, or 0.0001 to 0.005 per 1 mol of the ethylenically unsaturated monomer used for the polymerization. It may be a molar.
  • the amount of the surface cross-linking agent is 0.00001 mol or more, the cross-linking density on the surface portion of the water-absorbent resin particles is sufficiently increased, and the gel strength of the water-absorbent resin particles can be easily increased.
  • the amount of the surface cross-linking agent is 0.02 mol or less, it is easy to increase the water absorption amount of the water-absorbent resin particles.
  • the surface portion of the hydrogel polymer is treated (surface modification) with a surface modifier in either the drying step (moisture removal step) or a subsequent step. May be good.
  • the surface modification may be carried out, for example, before, during or after the surface cross-linking step.
  • Surface modification may be carried out after surface cross-linking.
  • a hydrogel polymer obtained by a reverse phase suspension polymerization method, an aqueous solution polymerization method, or another polymerization method when the hydrogel polymer is treated with a surface modifier after surface cross-linking,
  • the obtained water-absorbent resin particles tend to easily form a resin layer showing a high dry powder passing liquid absorption rate.
  • the surface modifier may be, for example, a surfactant such as an anionic surfactant, a cationic surfactant, an amphoteric surfactant, or a nonionic surfactant.
  • a surfactant such as an anionic surfactant, a cationic surfactant, an amphoteric surfactant, or a nonionic surfactant.
  • the HLB value of the nonionic surfactant used as the surface modifier may be, for example, 3 to 12, or 6 to 10.
  • the nonionic surfactant include sorbitan fatty acid esters such as sorbitan monolaurate.
  • the surface modifier is a nonionic surfactant having an HLB value within the above range, the obtained water-absorbent resin particles tend to easily form a resin layer showing a high dry powder flow-through liquid absorption rate.
  • the HLB value is measured by the Griffin method.
  • the amount of the surface modifier is 0.01 to 0.50 parts by mass, 0.02 to 0.40 parts by mass, or 0.04 with respect to 100 parts by mass of the ethylenically unsaturated monomer used for the polymerization. It may be ⁇ 0.30 parts by mass.
  • water and a hydrocarbon dispersion medium can be distilled off from the hydrogel polymer to obtain polymer particles which are dry products. it can.
  • the water-absorbent resin particles according to the present embodiment may be composed of only polymer particles, but various additional particles selected from, for example, a gel stabilizer, a metal chelating agent, a fluidity improver (lubricant), and the like. Ingredients can be further included. 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 water-absorbent resin particles may contain a plurality of inorganic particles arranged on the surface of the polymer particles. For example, by mixing the polymer particles and the inorganic particles, the inorganic particles can be arranged on the surface of the polymer particles.
  • the inorganic particles may be silica particles such as amorphous silica.
  • the ratio of the amount of the inorganic particles to the mass of the polymer particles is 0.2% by mass or more, 0.5% by mass or more, 1 It may be 0.0% by mass or more, 1.5% by mass or more, 5.0% by mass or less, or 3.5% by mass or less.
  • the inorganic particles here usually have a minute size as compared with the size of the polymer particles.
  • the average particle size of the inorganic particles may be 0.1 to 50 ⁇ m, 0.5 to 30 ⁇ m, or 1 to 20 ⁇ m.
  • the average particle size here can be a value measured by a dynamic light scattering method or a laser diffraction / scattering method.
  • FIG. 1 is a cross-sectional view showing an example of an auxiliary sheet.
  • the auxiliary sheet 60 shown in FIG. 1 has a resin layer 61 and two sheet base materials 62a and 62b.
  • the sheet base materials 62a and 62b are arranged on both sides of the resin layer 61.
  • the resin layer 61 is arranged inside the sheet base materials 62a and 62b.
  • the resin layer 61 is held in shape by being sandwiched between the two sheet base materials 62a and 62b.
  • the sheet base materials 62a and 62b may be two sheets, one folded sheet, or one bag.
  • the auxiliary sheet 60 may further have an adhesive 63a interposed between the sheet base material 62a and the resin layer 61, and further has an adhesive 63b interposed between the sheet base material 62b and the resin layer 61. You may have.
  • the adhesives 63a and 63b may be, for example, a water-based adhesive, a solvent-based adhesive, an elastic adhesive, an aerosol adhesive, a hot melt adhesive, or the like.
  • the thickness of the auxiliary sheet 60 may be, for example, 3.0 mm or less, 2.5 mm or less, 2.0 mm or less, or 1.8 mm or less, and 0.1 mm or more, 0.3 mm or more, or 0.5 mm or more. It may be.
  • the thickness can be measured using, for example, a dial thickness gauge JB manufactured by Ozaki Seisakusho Co., Ltd. (the stylus is made of aluminum having a diameter of 50 mm).
  • the resin layer 61 has the water-absorbent resin particles 61a according to the above-described embodiment and the fiber layer 61b containing a fibrous material.
  • the resin layer 61 does not have to have the fiber layer 61b.
  • the content of the water-absorbent resin particles in the resin layer may be 70 to 100% by mass, 80 to 100% by mass, or 90 to 100% by mass based on the mass of the resin layer 61.
  • the thickness of the resin layer 61 may be, for example, 2.0 mm or less, 1.5 mm or less, 1.0 mm or less, or 0.8 mm or less in a dry state, and is 0.1 mm or more, or 0.3 mm or more. You may.
  • the mass per unit area of the resin layer 61 may be 100 g / m 2 or less, 80 g / m 2 or less, 60 g / m 2 or less, or 40 g / m 2 or less, 10 g / m 2 or more, 20 g / m. It may be 2 or more, or 25 g / m 2 or more.
  • the fibrous material constituting the fiber layer 61b can be, for example, a cellulosic fiber, a synthetic fiber, or a combination thereof.
  • cellulosic fibers include crushed wood pulp, cotton, cotton linters, rayon and cellulosic acetate.
  • synthetic fibers include polyamide fibers, polyester fibers, and polyolefin fibers.
  • the fibrous material may be hydrophilic fibers (for example, pulp).
  • the resin layer 61 may further contain inorganic particles (for example, amorphous silica), a deodorant, an antibacterial agent, a fragrance, and the like.
  • the sheet base materials 62a and 62b may be, for example, non-woven fabric, tissue, or the like.
  • the two sheet base materials 62a and 62b can be the same or different non-woven fabrics.
  • the non-woven fabric may be a non-woven fabric composed of short fibers (that is, staples) (short-fiber non-woven fabric) or a non-woven fabric composed of long fibers (that is, filaments) (long-fiber non-woven fabric).
  • the staples may generally have a fiber length of several hundred mm or less.
  • the non-woven fabrics used as the sheet base materials 62a and 62b are thermal-bonded non-woven fabrics, air-through non-woven fabrics, resin-bonded non-woven fabrics, spunbonded non-woven fabrics, melt-blown non-woven fabrics, air-laid non-woven fabrics, spunlaced non-woven fabrics, point-bonded non-woven fabrics, or two or more kinds selected from these. It may be a laminate containing a non-woven fabric.
  • the non-woven fabric used as the sheet base materials 62a and 62b can be a non-woven fabric formed of synthetic fibers, natural fibers, or a combination thereof.
  • synthetic fibers include polyolefins such as polyethylene (PE) and polypropylene (PP), polyesters such as polyethylene terephthalate (PET), polytrimethylene terephthalate (PTT) and polyethylene naphthalate (PEN), polyamides such as nylon, and Examples thereof include fibers containing a synthetic resin selected from rayon.
  • Examples of natural fibers include fibers containing cotton, silk, hemp, or pulp (cellulose).
  • the fibers forming the non-woven fabric may be polyolefin fibers, polyester fibers or a combination thereof.
  • the sheet base materials 62a and 62b may be tissues.
  • the tissues used as the sheet base materials 62a and 62b may be natural fibers or natural fibers mixed with synthetic fibers.
  • the mass per unit area of the tissue may be 16 ⁇ 2 g / m 2.
  • the thickness of the tissue may be 0.12 ⁇ 0.02 mm.
  • the auxiliary sheet 60 can be obtained, for example, by sandwiching the resin layer 61 between the sheet base materials 62a and 62b and pressurizing the formed structure while heating it as necessary. If necessary, the adhesives 63a and 63b are arranged between the sheet base materials 62a and 62b and the resin layer 61.
  • the auxiliary sheet 60 is used, for example, for producing various absorbent articles.
  • absorbent articles include diapers (eg paper diapers), toilet training pants, incontinence pads, sanitary materials (sanitary napkins, tampons, etc.), sweat pads, pet sheets, toilet components, and animal waste treatment materials. Can be mentioned.
  • FIG. 2 is a cross-sectional view showing an example of an absorbent article.
  • the absorbent article 100 shown in FIG. 2 includes a water absorbing core 50, an auxiliary sheet 60, a liquid permeable sheet 30, and a liquid impermeable sheet 40.
  • the water absorption core 50 and the auxiliary sheet 60 are sandwiched between the liquid permeable sheet 30 and the liquid impermeable sheet 40.
  • the water absorption core 50 has an absorption layer 10 and two core wrap sheets 20a and 20b.
  • the core wrap sheets 20a and 20b are arranged on both sides of the absorption layer 10.
  • the absorbent layer 10 is arranged inside the core wrap sheets 20a and 20b, and is held in shape by being sandwiched between the two core wrap sheets.
  • the core wrap sheets 20a and 20b may be separate sheets, one folded sheet, or one bag body.
  • the water absorption core 50 does not have to have one or both of the two core wrap sheets 20a and 20b.
  • the core wrap sheet 20a may not be arranged between the absorption layer 10 and the auxiliary sheet 60.
  • the absorption layer 10 is sandwiched between one core wrap sheet 20b and the auxiliary sheet 60. It is kept in shape.
  • the water absorption core 50 may further have an adhesive interposed between the core wrap sheet 20a and the absorption layer 10, and further has an adhesive interposed between the core wrap sheet 20b and the absorption layer 10. May be.
  • An adhesive layer may be interposed between the core wrap sheets 20a and 20b on both sides and the absorption layer 10.
  • FIG. 3 is a plan view showing an example of an adhesive application pattern formed on the core wrap sheet.
  • the adhesive 21 shown in FIG. 3 forms a coating pattern composed of a plurality of linear portions arranged at intervals on the core wrap sheet 20a.
  • the coating pattern of the adhesive 21 may be linear, curved, dot-shaped, or a combination thereof.
  • the adhesive may be, for example, a water-based adhesive, a solvent-based adhesive, or a hot melt adhesive.
  • the absorption layer 10 has water-absorbent resin particles 10a and a fiber layer 10b containing a fibrous material.
  • the absorption layer 10 does not have to have the fiber layer 10b.
  • the content of the water-absorbent resin particles in the absorption layer may be 70 to 100% by mass, 80 to 100% by mass, or 90 to 100% by mass based on the mass of the absorption layer 10.
  • the water-absorbent resin particles 10a may be particles containing a polymer containing an ethylenically unsaturated monomer as a monomer unit.
  • the ethylenically unsaturated monomer may be a water-soluble monomer, and examples thereof include (meth) acrylic acid and salts thereof, 2- (meth) acrylamide-2-methylpropanesulfonic acid and its salts.
  • the ethylenically unsaturated monomer may be used alone or in combination of two or more.
  • the water-absorbent resin particles may be particles containing a polymer containing at least one of (meth) acrylic acid or a salt of (meth) acrylic acid as a monomer unit.
  • the water-absorbent resin particles 10a can be produced, for example, by a method including polymerizing a monomer containing an ethylenically unsaturated monomer.
  • the monomer polymerization method can be selected from, for example, a reverse phase suspension polymerization method, an aqueous solution polymerization method, a bulk polymerization method, and a precipitation polymerization method. From the viewpoint of ensuring good water absorption characteristics of the water-absorbent resin particles and easily controlling the polymerization reaction, a reverse phase suspension polymerization method or an aqueous solution polymerization method may be adopted.
  • the polymer constituting the water-absorbent resin particles 10a may be a crosslinked polymer.
  • the polymer may be crosslinked by self-crosslinking, cross-linking by reaction with a cross-linking agent, or both.
  • the water-absorbent resin particles may be surface-crosslinked by cross-linking at least the polymer of the surface layer portion with a cross-linking agent.
  • the water-absorbent resin particles 10a may contain various additional components in addition to the polymer of the ethylenically unsaturated monomer.
  • additional ingredients include gel stabilizers, metal chelating agents, and fluidity improvers (lubricants).
  • Additional components may be placed inside the polymer particles, including the polymer, 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 10a may be, for example, substantially spherical, crushed or granular, and particles in which primary particles having these shapes are aggregated may be formed.
  • the medium particle size of the water-absorbent resin particles may be 250 to 850 ⁇ m, 300 to 700 ⁇ m, or 300 to 600 ⁇ m.
  • the water absorption amount of the physiological saline may be 20 to 80 g / g, 30 to 70 g / g, or 40 to 65 g / g.
  • the thickness of the absorption layer 10 may be, for example, 20 mm or less, 15 mm or less, 10 mm or less, 5 mm or less, 4 mm or less, or 3 mm or less in a dry state, and may be 0.1 mm or more or 0.3 mm or more. Good.
  • the mass per unit area of the absorption layer 10 may be 1000 g / m 2 or less, 800 g / m 2 or less, or 600 g / m 2 or less, 100 g / m 2 or more, or 200 g / m 2 or more. May be good.
  • the fibrous material constituting the fiber layer 10b can be, for example, a cellulosic fiber, a synthetic fiber, or a combination thereof.
  • cellulosic fibers include crushed wood pulp, cotton, cotton linters, rayon and cellulosic acetate.
  • synthetic fibers include polyamide fibers, polyester fibers, and polyolefin fibers.
  • the fibrous material may be hydrophilic fibers (for example, pulp).
  • the absorption layer 10 may further contain an inorganic powder (for example, amorphous silica), a deodorant, an antibacterial agent, a fragrance, and the like.
  • an inorganic powder for example, amorphous silica
  • the absorption layer 10 may contain inorganic powder in addition to the inorganic particles in the water-absorbent resin particles 10a.
  • the core wrap sheets 20a and 20b may be, for example, a non-woven fabric.
  • the two core wrap sheets 20a and 20b can be the same or different non-woven fabrics.
  • the non-woven fabric may be a non-woven fabric composed of short fibers (that is, staples) (short-fiber non-woven fabric) or a non-woven fabric composed of long fibers (that is, filaments) (long-fiber non-woven fabric).
  • the staples may generally have a fiber length of several hundred mm or less.
  • the core wrap sheets 20a and 20b are laminated including a thermal bond non-woven fabric, an air-through non-woven fabric, a resin bond non-woven fabric, a spunbond non-woven fabric, a melt blow non-woven fabric, an air-laid non-woven fabric, a spunlace non-woven fabric, a point bond non-woven fabric, or two or more kinds of non-woven fabrics selected from these. It can be a body.
  • the non-woven fabric used as the core wrap sheets 20a and 20b can be a non-woven fabric formed of synthetic fibers, natural fibers, or a combination thereof.
  • synthetic fibers include polyolefins such as polyethylene (PE) and polypropylene (PP), polyesters such as polyethylene terephthalate (PET), polytrimethylene terephthalate (PTT) and polyethylene naphthalate (PEN), polyamides such as nylon, and Examples thereof include fibers containing a synthetic resin selected from rayon.
  • Examples of natural fibers include fibers containing cotton, silk, hemp, or pulp (cellulose).
  • the fibers forming the non-woven fabric may be polyolefin fibers, polyester fibers or a combination thereof.
  • the core wrap sheets 20a and 20b may be tissues.
  • the water-absorbing core 50 is sandwiched between, for example, the water-absorbent resin particles 10a or a mixture containing the water-absorbent resin particles 10a and the fibrous material and the core wrap sheets 20a and 20b, and the formed structure is heated as necessary. It can be obtained by the method of pressurizing. If necessary, an adhesive is placed between the core wrap sheets 20a and 20b and the water-absorbent resin particles 10a or a mixture containing the same.
  • the water-absorbing core substantially includes a fiber layer as a whole, in addition to the water-absorbing core in which the core wrap sheet 20a, the water-absorbent resin particles 10a, the absorption layer 10 composed of the fiber layer 10b, and the core wrap sheet 20b are arranged in this order. It may be in the form of no sheet.
  • FIG. 4 is a cross-sectional view of the water absorption core formed in a sheet shape, showing another example of the water absorption core.
  • the 4 includes a core wrap sheet 25a, an adhesive 26a, an absorption layer 10A made of water-absorbent resin particles, a core wrap sheet 25b, an absorption layer 10B made of water-absorbent resin particles, an adhesive 26b, and a core wrap.
  • the sheets 25c are arranged in this order.
  • the water-absorbent resin particles contained in the absorption layers 10A and 10B may be of the same type or different types.
  • the mass and thickness of each of the absorption layers 10A and 10B per unit area may be the same or different.
  • the liquid permeable sheet 30 is arranged at the position of the outermost layer on the side where the liquid to be absorbed enters.
  • the liquid permeable sheet 30 is arranged on the outside of the core wrap sheet 20b in contact with the core wrap sheet 20b.
  • the liquid permeable sheet 40 is arranged at the position of the outermost layer on the side opposite to the liquid permeable sheet 30 in the absorbent article 100.
  • the liquid impermeable sheet 40 is arranged on the outside of the core wrap sheet 20a in contact with the core wrap sheet 20a.
  • the liquid permeable sheet 30 and the liquid permeable sheet 40 have a main surface wider than the main surface of the water absorbing core 50, and the outer edges of the liquid permeable sheet 30 and the liquid permeable sheet 40 are an absorbing layer.
  • the magnitude relationship of the absorbent layer 10, the core wrap sheets 20a and 20b, the auxiliary sheet 60, the liquid permeable sheet 30, and the liquid permeable sheet 40 is appropriately adjusted according to the use of the absorbent article and the like.
  • the liquid permeable sheet 30 may be a non-woven fabric.
  • the non-woven fabric used as the liquid permeable sheet 30 may have appropriate hydrophilicity from the viewpoint of the liquid absorption performance of the absorbent article. From this point of view, the liquid permeable sheet 30 is a pulp and paper test method No. 1 by the Paper and Pulp Technology Association. A non-woven fabric having a hydrophilicity of 5 to 200 measured according to the measuring method of 68 (2000) may be used. The hydrophilicity of the non-woven fabric may be 10 to 150. Pulp and paper test method No. For details of 68, for example, WO2011 / 086843 can be referred to.
  • the non-woven fabric having hydrophilicity may be formed of fibers showing appropriate hydrophilicity such as rayon fiber, or obtained by hydrophilizing a hydrophobic chemical fiber such as polyolefin fiber or polyester fiber. It may be formed of rayon fibers.
  • a method for obtaining a non-woven fabric containing hydrophobic chemical fibers that have been hydrophobized for example, a method for obtaining a non-woven fabric by a spunbond method using a mixture of hydrophobic chemical fibers and a hydrophilic agent, hydrophobic chemistry.
  • Examples thereof include a method of accommodating a hydrophilic agent when producing a spunbonded nonwoven fabric from fibers, and a method of impregnating a spunbonded nonwoven fabric obtained by using a hydrophobic chemical fiber with a hydrophilic agent.
  • the hydrophilizing agent include anionic surfactants such as aliphatic sulfonates and higher alcohol sulfates, cationic surfactants such as quaternary ammonium salts, polyethylene glycol fatty acid esters, polyglycerin fatty acid esters, and sorbitan fatty acids.
  • Nonionic surfactants such as esters, silicone-based surfactants such as polyoxyalkylene-modified silicones, and stain-releasing agents made of polyester-based, polyamide-based, acrylic-based, and urethane-based resins are used.
  • the amount of texture (mass per unit area) of the non-woven fabric used as the liquid permeable sheet 30 is from the viewpoint of imparting good liquid permeability, flexibility, strength and cushioning property to the absorbent article, and the liquid of the absorbent article. From the viewpoint of increasing the permeation rate, it may be 5 to 200 g / m 2 , 8 to 150 g / m 2 , or 10 to 100 g / m 2 .
  • the thickness of the liquid permeable sheet 30 may be 20 to 1400 ⁇ m, 50 to 1200 ⁇ m, or 80 to 1000 ⁇ m.
  • the liquid impermeable sheet 40 prevents the liquid absorbed by the absorption layer 10 or the resin layer 61 from leaking to the outside from the liquid impermeable sheet 40 side.
  • the liquid impermeable sheet 40 may be a resin sheet or a non-woven fabric.
  • the resin sheet may be a sheet made of a synthetic resin such as polyethylene, polypropylene, or polyvinyl chloride.
  • the non-woven fabric may be a spunbond / melt blow / spunbond (SMS) non-woven fabric in which a water resistant melt blow non-woven fabric is sandwiched between high-strength spunbond non-woven fabrics.
  • SMS spunbond / melt blow / spunbond
  • the liquid permeable sheet 40 may be a composite sheet of a resin sheet and a non-woven fabric (for example, a spunbonded non-woven fabric or a spunlaced non-woven fabric).
  • the liquid impermeable sheet 40 may have breathability from the viewpoint that stuffiness at the time of wearing is reduced and discomfort given to the wearer can be reduced.
  • a sheet of low density polyethylene (LDPE) resin can be used as the liquid impermeable sheet 40 having breathability.
  • the basis weight (mass per unit area) of the liquid impermeable sheet 40 is 5 to 100 g / m 2 or 10 to 50 g / m 2. It may be.
  • the absorbent article 100 can be manufactured, for example, by a method including arranging the water absorbing core 50 and the auxiliary sheet 60 between the liquid permeable sheet 30 and the liquid impermeable sheet 40.
  • a laminate in which the liquid impermeable sheet 40, the auxiliary sheet 60, the water absorption core 50, and the liquid permeable sheet 30 are laminated in this order is pressurized as necessary.
  • the absorbent article 100 can also be obtained by arranging the permeable sheets 40 in this order and pressurizing the formed structure while heating if necessary.
  • each structural unit may be bonded with an adhesive.
  • the first-stage monomer aqueous solution prepared above was added to the separable flask, and after stirring for 10 minutes, 6.62 g of n-heptane was added as a surfactant to the sucrose stearic acid ester of HLB3. Mitsubishi Chemical Foods Co., Ltd., Ryoto Sugar Ester S-370) 0.736 g of a surfactant solution dissolved by heating is further added, and the inside of the system is sufficiently filled with nitrogen while stirring at a stirring speed of 550 rpm. After the replacement, the flask was immersed in a water bath at 70 ° C. to raise the temperature, and polymerization was carried out for 60 minutes to obtain a first-stage polymerization slurry solution.
  • ⁇ Second stage polymerization reaction> Take 128.8 g (1.44 mol) of an 80.5 mass% acrylic acid aqueous solution as a water-soluble ethylenically unsaturated monomer in a beaker having an internal volume of 500 mL, and while cooling from the outside, 27 mass% sodium hydroxide. After 159.0 g of the aqueous solution was added dropwise to neutralize 75 mol%, 0.090 g (0.333 mmol) of potassium persulfate was used as the water-soluble radical polymerization initiator, and ethylene glycol diglycidyl ether was used as the internal cross-linking agent. 0116 g (0.067 mmol) was added and dissolved to prepare a second-stage monomer aqueous solution.
  • the entire amount of the monomer aqueous solution in the second stage is added to the polymerized slurry liquid in the first stage.
  • the flask was again immersed in a water bath at 70 ° C. to raise the temperature, and the polymerization reaction was carried out for 60 minutes to obtain a hydrogel polymer.
  • n-heptane and water were heated in an oil bath at 125 ° C. to evaporate and dry to obtain a dried product of polymer particles.
  • the polymer particles are passed through a sieve having an opening of 850 ⁇ m, and 0.2% by mass of amorphous silica (Oriental Silicas Corporation, Toxile NP-S) with respect to the mass of the polymer particles is mixed with the polymer particles.
  • amorphous silica Oriental Silicas Corporation, Toxile NP-S
  • 233.0 g of water-absorbent resin particles A containing amorphous silica were obtained.
  • the medium particle size of the water-absorbent resin particles A was 128 ⁇ m.
  • the first-stage monomer aqueous solution prepared above was added to the separable flask, and after stirring for 10 minutes, 6.62 g of n-heptane was added as a surfactant to the sucrose stearic acid ester of HLB3. Mitsubishi Chemical Foods Co., Ltd., Ryoto Sugar Ester S-370) 0.736 g of a surfactant solution dissolved by heating is further added, and the inside of the system is sufficiently filled with nitrogen while stirring at a stirring speed of 550 rpm. After the replacement, the flask was immersed in a water bath at 70 ° C. to raise the temperature, and polymerization was carried out for 60 minutes to obtain a first-stage polymerization slurry solution.
  • ⁇ Second stage polymerization reaction> Take 128.8 g (1.44 mol) of an 80.5 mass% acrylic acid aqueous solution as a water-soluble ethylenically unsaturated monomer in a beaker having an internal volume of 500 mL, and while cooling from the outside, 27 mass% sodium hydroxide. After 159.0 g of the aqueous solution was added dropwise to neutralize 75 mol%, 0.129 g (0.476 mmol) of 2,2'-azobis (2-amidinopropane) dihydrochloride as a water-soluble radical polymerization initiator.
  • the entire amount of the monomer aqueous solution in the second stage is added to the polymerized slurry liquid in the first stage.
  • the inside of the system was replaced with nitrogen for 30 minutes, and then the flask was again immersed in a water bath at 70 ° C. to raise the temperature, and the polymerization reaction was carried out for 60 minutes. As a result, a hydrogel polymer was obtained.
  • n-heptane and water were heated in an oil bath at 125 ° C. to evaporate and dry to obtain a dried product of polymer particles.
  • the polymer particles are passed through a sieve having an opening of 850 ⁇ m, 0.2% by mass of amorphous silica (Oriental Silicas Corporation, Toxile NP-S) is mixed with respect to the mass of the polymer particles, and a water-absorbent resin is mixed. 228.5 g of particle C was obtained.
  • the medium particle size of the water-absorbent resin particles C was 354 ⁇ m.
  • Manufacturing example 4 229.0 g of water-absorbent resin particles D were obtained in the same manner as in Production Example 3 except that 216.7 g of water was extracted from the system by azeotropic distillation.
  • the medium particle size of the water-absorbent resin particles D was 348 ⁇ m.
  • Production example 5 Water-absorbent resin particles E227.6 g were obtained in the same manner as in Production Example 3 except that 201.4 g of water was extracted from the system by azeotropic distillation.
  • the medium particle size of the water-absorbent resin particles E was 356 ⁇ m.
  • Production example 6 Inner diameter 11 cm, contents equipped with a reflux condenser, a dropping funnel, a nitrogen gas introduction pipe, and a stirrer (a stirrer blade having two stages of four inclined paddle blades (surface treated with fluororesin) with a blade diameter of 5 cm).
  • n-heptane as a hydrocarbon dispersion medium
  • sorbitan monolaurate Naonion LP-20R, HLB value: 8.6, manufactured by NOF CORPORATION
  • the mixture was obtained by addition.
  • the sorbitan monolaurate was dissolved in n-heptane by heating the mixture to 50 ° C. while stirring at a stirring speed of 300 rpm, and then the mixture was cooled to 40 ° C.
  • the inside of the system was sufficiently replaced with nitrogen. Then, the flask was immersed in a water bath at 70 ° C. while stirring at a rotation speed of 700 rpm of the stirrer, and then held for 60 minutes to complete the polymerization, thereby obtaining a hydrogel polymer.
  • amorphous silica (Oriental Silicas Corporation, oriental silicas corporation, etc.) was added to the polymer solution containing the produced hydrogel polymer, n-heptane and a surfactant as a powdery inorganic flocculant.
  • the flask containing the reaction solution was immersed in an oil bath at 125 ° C., and 98.0 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 maintained at an internal temperature of 83 ⁇ 2 ° C. for 2 hours.
  • ethylene glycol diglycidyl ether 0.475 mmol
  • water and n-heptane were heated in an oil bath at 125 ° C. to evaporate, and dried until almost no evaporation from the system was distilled off to obtain a dried product of polymer particles.
  • the polymer particles were passed through a sieve having an opening of 850 ⁇ m to obtain 90.1 g of water-absorbent resin particles F.
  • the medium particle size of the water-absorbent resin particles F was 352 ⁇ m.
  • Production example 7 90.6 g of water-absorbent resin particles G were obtained in the same manner as in Production Example 6 except that the powdery inorganic flocculant was not added to the hydrogel polymer.
  • the medium particle size of the water-absorbent resin particles G was 156 ⁇ m.
  • Production Example 8 104.0 g of water was extracted from the system by azeotropic distillation, and the surface cross-linking agent was changed to 8.28 g of an ethylene glycol diglycidyl ether aqueous solution (ethylene glycol diglycidyl ether: 0.951 mmol). Except for the above, 90.3 g of water-absorbent resin particles H were obtained in the same manner as in Production Example 6. The medium particle size of the water-absorbent resin particles H was 420 ⁇ m.
  • Production Example 11 In the preparation of the water-containing gel polymer in the second stage, the temperature inside the separable flask was changed to 28 ° C instead of 31 ° C, and 234.7 g of water was extracted from the system by azeotropic distillation. 230.1 g of water-absorbent resin particles L were obtained in the same manner as in Production Example 3 except that no surfactant was added after the surface cross-linking step. The medium particle size of the water-absorbent resin particles L was 308 ⁇ m.
  • Production Example 12 In the preparation of the water-containing gel polymer in the second stage, the temperature in the separable flask was changed to 25 ° C instead of 31 ° C, and in the water-containing gel polymer after the polymerization in the second stage, co-boiling was performed. Similar to Production Example 1, except that 256.5 g of water was extracted from the system by distillation, no surfactant was added after the surface cross-linking step, and amorphous silica was not mixed. 227.2 g of water-absorbent resin particles M were obtained. The medium particle size of the water-absorbent resin particles M was 351 ⁇ m.
  • Production example 14 A round-bottomed cylindrical separable flask with an inner diameter of 11 cm and a volume 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. Got ready. To this flask, take 293 g of n-heptane as a hydrocarbon dispersion medium, add 0.736 g of a maleic anhydride-modified ethylene-propylene copolymer (Mitsui Chemicals Co., Ltd., High Wax 1105A) as a polymer-based dispersant, and stir. The temperature was raised to 80 ° C. to dissolve the dispersant, and then cooled to 50 ° C.
  • a maleic anhydride-modified ethylene-propylene copolymer Mitsubishi Chemicals Co., Ltd., High Wax 1105A
  • the monomer aqueous solution prepared above was added to the separable flask, and after stirring for 10 minutes, sucrose stearic acid ester of HLB3 as a surfactant in 6.62 g of n-heptane (Mitsubishi Chemical Foods Co., Ltd.) , Ryoto Sugar Ester S-370) 0.736 g of a surfactant solution is further added, and the inside of the system is sufficiently replaced with nitrogen while stirring at a stirring speed of 400 rpm, and then the flask.
  • the flask was immersed in an oil bath set at 125 ° C., and 116 g of water was extracted from the system while refluxing n-heptane by azeotropic distillation of n-heptane and water. Then, 1.84 g (0.211 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 flask was kept at 83 ° C. for 2 hours.
  • n-heptane and water were evaporated at 125 ° C. and dried to obtain a dried product of polymer particles.
  • the polymer particles are passed through a sieve having an opening of 850 ⁇ m, and 0.2% by mass of amorphous silica (Oriental Silicas Corporation, Toxile NP-S) with respect to the mass of the polymer particles is mixed with the polymer particles.
  • 90.9 g of water-absorbent resin particles P containing amorphous silica were obtained.
  • the medium particle size of the water-absorbent resin particles P was 422 ⁇ m.
  • the medium particle size of the particles was measured by the following procedure. That is, from the top, the JIS standard sieve has a mesh size of 600 ⁇ m, a mesh size of 500 ⁇ m, a mesh size of 425 ⁇ m, a mesh size of 300 ⁇ m, a mesh size of 250 ⁇ m, a mesh size of 180 ⁇ m, and a mesh size of 150 ⁇ m. , And the saucer in that order. 50 g of particles were placed in the best combined sieve and classified according to JIS Z 8815 (1994) using a low-tap shaker (manufactured by Iida Seisakusho Co., Ltd.).
  • 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 particle size distribution on the sieve in order from the largest particle size. By connecting the plots on the probability paper with a straight line, the particle size corresponding to the cumulative mass percentage of 50% by mass was obtained as the medium particle size.
  • Air-laid non-woven fabric-2 with hot melt coating machine (Henkel Co., Ltd., pump: Marshal150, table: XA-DT, tank set temperature: 150 ° C, hose set temperature: 165 ° C, gun head set temperature: 170 ° C)
  • 0.2 g of hot melt adhesive (Henkel Japan Ltd., ME-765E) was applied in 12 linear lines at 10 mm intervals.
  • the adhesive application pattern was a spiral stripe.
  • the surface of the air-laid non-woven fabric-2 to which the hot melt was attached was aligned with the surface on which the water-absorbent resin particles of the air-through non-woven fabric were sprayed, and sandwiched between release papers and turned upside down. Then, the release paper and the air-laid non-woven fabric-1 were removed.
  • the water absorption core A has the same configuration as the water absorption core shown in FIG.
  • Production example 16 Water-absorbent resin particles (Aquakeep SA60S manufactured by Sumitomo Seika Chemical Co., Ltd., water absorption of physiological saline 60 g / g, medium particle diameter 342 ⁇ m) using an air flow type mixer (Padformer manufactured by Otec Co., Ltd.) A sheet-shaped absorbent layer having a size of 40 cm ⁇ 10 cm was prepared by uniformly mixing 12.0 g and 3.0 g of pulverized pulp by air papermaking.
  • water absorption is performed by applying a load of 196 kPa to the entire surface for 30 seconds with the upper and lower sides of the absorbent layer sandwiched between two sheets of tissue having the same size as the sheet-shaped absorbent layer and having a basis weight of 16 g / m 2.
  • the core was made. This was designated as the water absorption core B.
  • the produced water-absorbing core B has an absorbing layer made of water-absorbing resin particles and crushed pulp arranged between two sheets of tissue.
  • Example 1 (Preparation of auxiliary sheet) Two pieces of tissue having a basis weight of 16 g / m 2 were cut into a size of 14 cm ⁇ 42 cm to obtain an upper sheet base material and a lower sheet base material of the auxiliary sheet. After uniformly applying 0.3 g of adhesive (3M Spray Glue 77 manufactured by 3M Japan Ltd.) to the inner surface of the roll of the lower sheet base material, promptly airflow type mixing device (manufactured by Otec Co., Ltd., pad former) ) was used to uniformly spray 1.5 g of the water-absorbent resin particles A prepared in Production Example 1 over a range of 10 cm ⁇ 40 cm in the center of the lower sheet base material.
  • adhesive 3M Spray Glue 77 manufactured by 3M Japan Ltd.
  • an adhesive (3M spray glue 77 manufactured by 3M Japan Ltd.) was uniformly applied to the upper sheet base material.
  • the surface coated with the adhesive of the upper sheet base material is overlapped with the surface on which the water-absorbent resin of the lower sheet base material is sprayed, with both ends aligned, and the entire surface is adhered to the area where the water-absorbent resin is sprayed. (10 cm ⁇ 40 cm) was cut out to obtain an auxiliary sheet.
  • Example 2 An absorbent article was obtained in the same manner as in Example 1 except that the water-absorbent resin particles for the auxiliary sheet were changed to the water-absorbent resin particles B produced in Production Example 2.
  • Example 3 An absorbent article was obtained in the same manner as in Example 1 except that the water-absorbent resin particles for the auxiliary sheet were changed to the water-absorbent resin particles C produced in Production Example 3.
  • Example 4 An absorbent article was obtained in the same manner as in Example 1 except that the water-absorbent resin particles for the auxiliary sheet were changed to the water-absorbent resin particles D produced in Production Example 4.
  • Example 5 An absorbent article was obtained in the same manner as in Example 1 except that the water-absorbent resin particles for the auxiliary sheet were changed to the water-absorbent resin particles E produced in Production Example 5.
  • Example 6 An absorbent article was obtained in the same manner as in Example 1 except that the water-absorbent resin particles for the auxiliary sheet were changed to the water-absorbent resin particles F produced in Production Example 6.
  • Example 7 An absorbent article was obtained in the same manner as in Example 1 except that the water-absorbent resin particles for the auxiliary sheet were changed to the water-absorbent resin particles G produced in Production Example 7.
  • Example 8 An absorbent article was obtained in the same manner as in Example 1 except that the water-absorbent resin particles for the auxiliary sheet were changed to the water-absorbent resin particles H produced in Production Example 8.
  • Example 9 An absorbent article was obtained in the same manner as in Example 1 except that the water-absorbent resin particles for the auxiliary sheet were changed to the water-absorbent resin particles J produced in Production Example 9.
  • Example 10 The upper sheet base material and the lower sheet base material of the auxiliary sheet were changed to spunbonded non-woven fabric (manufactured by Toray Polytech (Nantong) Co., Ltd., trade name: LIVESEN) having a basis weight of 17 g / m 2.
  • An absorbent article was obtained in the same manner as in Example 1 except that the water-absorbent resin particles for the sheet were changed to the water-absorbent resin particles F produced in Production Example 6.
  • Example 11 The upper sheet base material and the lower sheet base material of the auxiliary sheet were changed to air-through non-woven fabric manufactured by Rengo Nonwoven Products Co., Ltd. with a grain size of 21 g / m 2, and water-absorbent resin particles for the auxiliary sheet were produced.
  • An absorbent article was obtained in the same manner as in Example 1 except that the particles were changed to the water-absorbent resin particles F produced in 1.
  • Example 12 The upper sheet base material of the auxiliary sheet was changed to an air-through non-woven fabric manufactured by Hualong (Nanjining) with a grain size of 45 g / m 2, and the water-absorbent resin particles for the auxiliary sheet were prepared in Production Example 6. An absorbent article was obtained in the same manner as in Example 1 except that it was changed to F.
  • Example 13 (Preparation of auxiliary sheet) By using an air flow type mixer (Padformer manufactured by Otec Co., Ltd.) to uniformly mix 1.5 g of the water-absorbent resin particles F and 1.5 g of crushed pulp of Production Example 6 by air papermaking, the size is 40 cm ⁇ 10 cm. A sheet-shaped resin layer having a size was prepared. Next, a load of 196 kPa is applied to the entire surface for 30 seconds while the resin layer is sandwiched between two sheets of tissue having the same size as the sheet-shaped resin layer and having a grain size of 16 g / m 2, and pressed. An auxiliary sheet was obtained in which a resin layer composed of water-absorbent resin particles and crushed pulp was arranged between two sheets of tissue.
  • an air flow type mixer Padformer manufactured by Otec Co., Ltd.
  • Example 14 The same as in Example 1 except that the water-absorbent resin particles for the auxiliary sheet were changed to the water-absorbent resin particles F produced in Production Example 6 and the amount of the water-absorbent resin particles used was changed to 1.0 g. An absorbent article was obtained.
  • Example 15 An auxiliary sheet was obtained in the same manner as in Example 1 except that the water-absorbent resin particles for the auxiliary sheet were changed to the water-absorbent resin particles F produced in Production Example 6.
  • the water-absorbing core B produced in Production Example 16 was placed on the obtained auxiliary sheet to obtain an absorbent article.
  • Example 16 The same as in Example 1 except that the water-absorbent resin particles for the auxiliary sheet were changed to the water-absorbent resin particles F produced in Production Example 6 and the amount of the water-absorbent resin particles used was changed to 0.4 g. An absorbent article was obtained.
  • Comparative Example 1 Only the water-absorbing core A produced in Production Example 15 without using the auxiliary sheet was used as the absorbent article for the test.
  • the water-absorbing core was prepared in the same manner as in Production Example 15 except that the amount of the water-absorbent resin particles sprayed between the air-laid non-woven fabric-2 and the air-through non-woven fabric of Production Example 15 was changed from 6.0 g to 5.0 g. Obtained. Only the above-mentioned water-absorbing core obtained without using the auxiliary sheet was used as an absorbent article for testing.
  • Comparative Example 3 An absorbent article was obtained in the same manner as in Example 1 except that the water-absorbent resin particles were not used.
  • Comparative Example 4 An absorbent article was obtained in the same manner as in Example 1 except that the water-absorbent resin particles for the auxiliary sheet were changed to the water-absorbent resin particles K produced in Production Example 10.
  • Comparative Example 5 An absorbent article was obtained in the same manner as in Example 1 except that the water-absorbent resin particles for the auxiliary sheet were changed to the water-absorbent resin particles L produced in Production Example 11.
  • Comparative Example 6 An absorbent article was obtained in the same manner as in Example 1 except that the water-absorbent resin particles for the auxiliary sheet were changed to the water-absorbent resin particles M produced in Production Example 12.
  • Comparative Example 7 An absorbent article was obtained in the same manner as in Example 1 except that the water-absorbent resin particles for the auxiliary sheet were changed to the water-absorbent resin particles N produced in Production Example 13.
  • Comparative Example 8 An absorbent article was obtained in the same manner as in Example 1 except that the water-absorbent resin particles for the auxiliary sheet were changed to the water-absorbent resin particles P produced in Production Example 14.
  • dry powder passing liquid absorption rate dry powder passing liquid absorbing amount (g) / 0.2 g artificial urine saturated liquid absorbing amount (g) of the water-absorbent resin.
  • dry powder passing liquid absorption amount and the artificial urine saturated liquid absorption amount of 0.2 g were measured and calculated by the methods shown below.
  • FIG. 5 is a schematic view showing a method for measuring the liquid absorption rate of dry powder.
  • 61a was uniformly sprayed, and the total mass Wb of the container and the water-absorbent resin particles 61a sprayed in the container was measured.
  • a plastic beaker with an opening diameter of 60 mm and a height of 70 mm was used as the receiver 53, and the cylindrical container 52 was placed on the receiver 53.
  • the dropping funnel 54 was installed so that the distance H between the tip 54a and the upper surface of the mesh 51 was 13 mm and the tip 54a was located above the center of the bottom surface of the cylindrical container 52.
  • Artificial urine 45 (20 mL) adjusted to a liquid temperature of 25 ° C. was injected at a constant rate of 8 mL / sec, and the stopwatch was started at the same time.
  • the artificial urine diffuses over the entire bottom surface of the cylindrical container 52, passes through the mesh 51 and falls into the receiver 53, but a part of the artificial urine is absorbed by the water-absorbent resin particles 61a.
  • the water-absorbent resin particles 61a absorb the artificial urine 45 to form a swollen gel.
  • the total mass Wa of the cylindrical container 52 and the swollen gel in the cylindrical container 52 was measured.
  • the amount of dry powder flowing through the liquid (g) was determined by Wa-Wb.
  • the mass Wd (g) of the sieve containing the swelling gel was measured, and the artificial urine saturated liquid absorption amount was determined by the following formula.
  • -Artificial urine saturated liquid absorption (g / g) (Wd-Wc) /2.0
  • -0.2 g of artificial urine saturated liquid absorption (g) 0.2 x artificial urine saturated liquid absorption (g / g)
  • auxiliary sheet thickness evaluation The thickness of the auxiliary sheet was measured using a precision thickness measuring instrument (manufactured by Ozaki Seisakusho, dial thickness gauge JB, stylus: aluminum ⁇ 50 mm). The measurement was performed at a position where the stylus was in contact with the central portion of the auxiliary sheet, and the average of the values measured three times was taken as the thickness (mm) of the auxiliary sheet.
  • FIG. 6 is a schematic view showing an apparatus for evaluating liquid leakage of an absorbent article.
  • the liquid leakage property at the initial stage of liquid absorption of the absorbent article 100 for testing was evaluated by the following procedures (i), (ii), (iii) and (iv). ..
  • the results are shown in Table 1.
  • the resin in the table represents water-absorbent resin particles, and gsm represents g / m 2 .
  • (I) is a mechanical fastener (3M mechanical fastener hook), vertical 45cm, was cut to the size of the acrylic resin plate 1 having a rectangular main surface of the lateral 62cm, was adhered to the entire main surface S 1 of the acrylic resin plate 1.
  • On the main surface S 1 of the acrylic resin plate 1 is extremely fine irregularities are caused by mechanical fasteners, no retention and absorption of liquids on the main surface S 1 of the acrylic resin plate 1.
  • the long side of the acrylic resin plate 1 was parallel to the horizontal plane, and the main surface of the acrylic resin plate 1 and the horizontal plane S 0 were fixed so as to form 45 ⁇ 2 degrees.
  • a fixed main surface S 1 of the acrylic resin plate 1, the absorbent article 100 for testing, in a direction that long sides are perpendicular to the long side of the acrylic resin plate 1, an absorbent article for testing 100 The lower end of the acrylic resin plate 1 was attached so as to be at the same position as the lower end of the acrylic resin plate 1.
  • the test absorbent article 100 composed of the water absorption core and the auxiliary sheet was attached on the acrylic resin plate 1 so that the water absorption core was on the front side.
  • the upper end of the absorbent article 100 for testing was fixed to the acrylic resin plate 1 with an adhesive tape to prevent it from falling.
  • the loading point is 8 cm above the center of the absorption core in the absorbent article 100 for testing, and from a position 1 cm vertically above the loading point, the dropping funnel 42 (300 mL of dropping funnel manufactured by Cosmos Bead Co., Ltd., tip) An inner diameter of 8 mm ⁇ 6 mm) was used to inject a predetermined amount of artificial urine 45 adjusted to a liquid temperature of 25 ° C. at a rate of 8 mL / sec.
  • the injection amount of artificial urine 45 when using the water-absorbing core A having an absorption layer made of water-absorbent resin particles is 80 mL, and when using the water-absorbing core B having an absorption layer made of water-absorbent resin particles and crushed pulp.
  • the injection amount of artificial urine 45 was 120 mL (Examples or comparative examples marked with * in Table 1).
  • (Iv) The artificial urine leaked from the absorbent article 100 for testing was collected in a metal tray 44 previously placed below the absorbent article 100 and placed on the balance. The collected artificial urine was weighed, and the ratio (%) of the amount of leaked artificial urine (g) to the input amount (g) of artificial urine was calculated.
  • Table 1 shows the evaluation results. It has been shown that an absorbent article having an auxiliary sheet prepared by using water-absorbent resin particles having a dry powder passing liquid absorption rate of a specific numerical value improves liquid leakage in the initial stage of liquid absorption.
  • 10, 10A, 10B Absorbent layer, 10a ... Water-absorbent resin particles, 10b ... Fiber layer, 20a, 20b ... Core wrap sheet, 21 ... Adhesive, 25a, 25b, 25c ... Core wrap sheet, 26a, 26b ... Adhesive , 30 ... Liquid permeable sheet, 40 ... Liquid permeable sheet, 50 ... Water absorption core, 51 ... Mesh (mesh-like bottom), 52 ... Cylindrical container, 60 ... Auxiliary sheet, 61 ... Resin layer, 61a ... Water absorption Sex resin particles, 61b ... fiber layer, 62a, 62b ... sheet base material, 63a, 63b ... adhesive, 100 ... absorbent article.
  • 10a Water-absorbent resin particles, 10b ... Fiber layer, 20a, 20b ... Core wrap sheet, 21 ... Adhesive, 25a, 25b, 25c ... Core wrap sheet, 26a, 26

Landscapes

  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Biomedical Technology (AREA)
  • Heart & Thoracic Surgery (AREA)
  • Vascular Medicine (AREA)
  • Epidemiology (AREA)
  • Animal Behavior & Ethology (AREA)
  • General Health & Medical Sciences (AREA)
  • Public Health (AREA)
  • Veterinary Medicine (AREA)
  • Solid-Sorbent Or Filter-Aiding Compositions (AREA)
  • Absorbent Articles And Supports Therefor (AREA)

Abstract

L'invention concerne un article absorbant comprenant : un noyau absorbant l'eau ; une feuille auxiliaire qui complète l'absorption de liquide par le noyau absorbant l'eau ; une feuille imperméable aux liquides ; et une feuille perméable aux liquides, la feuille imperméable aux liquides, la feuille auxiliaire, le noyau absorbant l'eau et la feuille perméable aux liquides étant agencés dans cet ordre. La feuille auxiliaire est pourvue d'une couche de résine contenant des particules de résine absorbant l'eau, et le taux d'absorption de liquide de poudre sèche des particules de résine absorbant l'eau est de 0,25 à 1,0.
PCT/JP2020/031838 2019-08-26 2020-08-24 Article absorbant et feuille auxiliaire WO2021039714A1 (fr)

Priority Applications (3)

Application Number Priority Date Filing Date Title
KR1020227008321A KR20220050917A (ko) 2019-08-26 2020-08-24 흡수성 물품 및 보조 시트
JP2021542886A JP7457718B2 (ja) 2019-08-26 2020-08-24 吸収性物品及び補助シート
CN202080059123.6A CN114269310B (zh) 2019-08-26 2020-08-24 吸收性物品及辅助片

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2019-154028 2019-08-26
JP2019154028 2019-08-26

Publications (1)

Publication Number Publication Date
WO2021039714A1 true WO2021039714A1 (fr) 2021-03-04

Family

ID=74684183

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2020/031838 WO2021039714A1 (fr) 2019-08-26 2020-08-24 Article absorbant et feuille auxiliaire

Country Status (4)

Country Link
JP (1) JP7457718B2 (fr)
KR (1) KR20220050917A (fr)
CN (1) CN114269310B (fr)
WO (1) WO2021039714A1 (fr)

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2013018571A1 (fr) * 2011-08-03 2013-02-07 住友精化株式会社 Particules de résine absorbant l'eau, procédé pour la fabrication de particules de résine absorbant l'eau, corps d'absorption, article absorbant et matériau d'étanchéité à l'eau
JP2014073448A (ja) * 2012-10-03 2014-04-24 Nippon Shokubai Co Ltd 粒子状吸水剤及びその製造方法
JP2016112047A (ja) * 2014-12-11 2016-06-23 株式会社リブドゥコーポレーション 吸収性物品用シート部材および吸収性物品
JP2017177065A (ja) * 2016-03-31 2017-10-05 株式会社日本触媒 吸水剤の製造方法

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CA2781165C (fr) * 2009-11-27 2017-05-09 Sumitomo Seika Chemicals Co., Ltd. Procede de production de particules de resine absorbant l'eau, particules de resine absorbant l'eau, materiau stoppant l'eau et article absorbant
JP6050685B2 (ja) * 2011-02-08 2016-12-21 住友精化株式会社 吸水性樹脂の製造方法
JP2012183175A (ja) 2011-03-04 2012-09-27 Sumitomo Seika Chem Co Ltd 吸水シート構成体
JP6004729B2 (ja) * 2012-04-26 2016-10-12 株式会社リブドゥコーポレーション 吸収性物品
JP7291622B2 (ja) * 2017-03-31 2023-06-15 住友精化株式会社 吸水性樹脂粒子

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2013018571A1 (fr) * 2011-08-03 2013-02-07 住友精化株式会社 Particules de résine absorbant l'eau, procédé pour la fabrication de particules de résine absorbant l'eau, corps d'absorption, article absorbant et matériau d'étanchéité à l'eau
JP2014073448A (ja) * 2012-10-03 2014-04-24 Nippon Shokubai Co Ltd 粒子状吸水剤及びその製造方法
JP2016112047A (ja) * 2014-12-11 2016-06-23 株式会社リブドゥコーポレーション 吸収性物品用シート部材および吸収性物品
JP2017177065A (ja) * 2016-03-31 2017-10-05 株式会社日本触媒 吸水剤の製造方法

Also Published As

Publication number Publication date
CN114269310B (zh) 2023-07-11
CN114269310A (zh) 2022-04-01
KR20220050917A (ko) 2022-04-25
JP7457718B2 (ja) 2024-03-28
JPWO2021039714A1 (fr) 2021-03-04

Similar Documents

Publication Publication Date Title
JP6828222B1 (ja) 吸水性樹脂粒子、吸収性物品、吸水性樹脂粒子を製造する方法、及び吸収体の加圧下での吸収量を高める方法
WO2020184386A1 (fr) Particules de résine absorbant l'eau, article absorbant, procédé de fabrication de particules de résine absorbant l'eau, procédé pour faciliter la perméation d'une solution saline physiologique dans un corps absorbant
EP3895676A1 (fr) Article absorbant
EP3896118A1 (fr) Particules de résine absorbantes, corps absorbant, article absorbant, et procédé de mesure de puissance d'absorption de liquide
JP7585210B2 (ja) 吸水シート及び吸収性物品
WO2021075508A1 (fr) Article absorbant et feuille auxiliaire
JP6856826B1 (ja) 吸水性樹脂粒子
EP3896095A1 (fr) Particules de résine absorbantes, corps absorbant, et article absorbant
US20220143576A1 (en) Water absorbing resin particles and method for producing same, absorbent body, and absorbent article
WO2021075507A1 (fr) Absorbeur
WO2021039714A1 (fr) Article absorbant et feuille auxiliaire
WO2021132266A1 (fr) Particules de résine absorbante, absorbeur, feuille absorbante, article absorbant et procédé de production de particules de résine absorbante
US20220219140A1 (en) Water-absorbent resin particles
US20220151842A1 (en) Absorbent body, absorbent article and method for adjusting permeation speed
WO2021039713A1 (fr) Article absorbant et feuille auxiliaire
JP6889811B2 (ja) 吸水性樹脂粒子、吸収性物品、吸水性樹脂粒子を製造する方法、及び吸収性物品の液漏れを抑制する方法
JP7091556B2 (ja) 吸水性樹脂粒子、及び吸水シート
JP6775050B2 (ja) 吸収性物品
WO2021187501A1 (fr) Feuille absorbant l'eau et article absorbant
JP6752320B2 (ja) 吸収性物品及びその製造方法
JP6775051B2 (ja) 吸収性物品
US12274999B2 (en) Water absorbent resin particles, absorbent, absorbent article and liquid suction power measurement method
WO2020218166A1 (fr) Particules de resine absorbante
EP3960795A1 (fr) Particules de resine absorbante, corps absorbant et article absorbant
US20220023487A1 (en) Water-absorbent resin particles, absorbent body, and absorbent article

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: 20856568

Country of ref document: EP

Kind code of ref document: A1

ENP Entry into the national phase

Ref document number: 2021542886

Country of ref document: JP

Kind code of ref document: A

NENP Non-entry into the national phase

Ref country code: DE

ENP Entry into the national phase

Ref document number: 20227008321

Country of ref document: KR

Kind code of ref document: A

122 Ep: pct application non-entry in european phase

Ref document number: 20856568

Country of ref document: EP

Kind code of ref document: A1