US20170210831A1 - Water-absorbent resin and method of producing water-absorbent resin - Google Patents

Water-absorbent resin and method of producing water-absorbent resin Download PDF

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US20170210831A1
US20170210831A1 US15/324,753 US201415324753A US2017210831A1 US 20170210831 A1 US20170210831 A1 US 20170210831A1 US 201415324753 A US201415324753 A US 201415324753A US 2017210831 A1 US2017210831 A1 US 2017210831A1
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Prior art keywords
water
absorbent resin
load
poly
diglycidyl ether
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Tetsuhiro Hinayama
Masahiro Murakami
Hiroki Yabuguchi
Hideki Yokoyama
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Sumitomo Seika Chemicals Co Ltd
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Sumitomo Seika Chemicals Co Ltd
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Priority to US16/804,095 priority Critical patent/US11136420B2/en
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    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F2/00—Processes of polymerisation
    • C08F2/32—Polymerisation in water-in-oil emulsions
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F8/00—Chemical modification by after-treatment
    • C08F8/14—Esterification
    • 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
    • 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 articles specially adapted to be worn around the waist, e.g. diapers
    • 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
    • A61L—METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES
    • A61L15/00—Chemical aspects of, or use of materials for, bandages, dressings or absorbent pads
    • A61L15/16—Bandages, dressings or absorbent pads for physiological fluids such as urine or blood, e.g. sanitary towels, tampons
    • A61L15/22—Bandages, dressings or absorbent pads for physiological fluids such as urine or blood, e.g. sanitary towels, tampons containing macromolecular materials
    • A61L15/24—Macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds; Derivatives thereof
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61L—METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES
    • A61L15/00—Chemical aspects of, or use of materials for, bandages, dressings or absorbent pads
    • A61L15/16—Bandages, dressings or absorbent pads for physiological fluids such as urine or blood, e.g. sanitary towels, tampons
    • A61L15/42—Use of materials characterised by their function or physical properties
    • A61L15/60—Liquid-swellable gel-forming materials, e.g. super-absorbents
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
    • B01J20/22—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising organic material
    • B01J20/26—Synthetic macromolecular compounds
    • B01J20/265—Synthetic macromolecular compounds modified or post-treated polymers
    • B01J20/267—Cross-linked polymers
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J3/00—Processes of treating or compounding macromolecular substances
    • C08J3/24—Crosslinking, e.g. vulcanising, of macromolecules
    • C08J3/245—Differential crosslinking of one polymer with one crosslinking type, e.g. surface crosslinking
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K5/00—Use of organic ingredients
    • C08K5/04—Oxygen-containing compounds
    • C08K5/14—Peroxides
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K5/00—Use of organic ingredients
    • C08K5/16—Nitrogen-containing compounds
    • C08K5/22—Compounds containing nitrogen bound to another nitrogen atom
    • C08K5/23—Azo-compounds
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J2205/00—Foams characterised by their properties
    • C08J2205/02—Foams characterised by their properties the finished foam itself being a gel or a gel being temporarily formed when processing the foamable composition
    • C08J2205/022—Hydrogel, i.e. a gel containing an aqueous composition

Definitions

  • the present invention relates to a water-absorbent resin and a method of producing the water-absorbent resin. More specifically, the present invention relates to a water-absorbent resin comprising an absorbent material suitably used for hygienic materials such as disposable diapers, sanitary napkins and incontinence pads, and also relates to a method of producing such the water-absorbent resin.
  • water-absorbent resins have been widely used in the field of hygienic materials such as disposable diapers, sanitary napkins and incontinence pads.
  • crosslinked products of partially neutralized polymers of acrylic acid salt are preferred because they have many advantages, including the followings: they have better water absorption performance; their raw materials such as acrylic acid are easily and industrially available, and therefore they can be produced with stable quality and low cost; and they are more resistant to decomposition and deterioration.
  • Preferred properties of water-absorbent resins for hygienic materials such as sanitary napkins and disposable diapers include a high water-retention capacity, a better water-absorption rate, a high water-absorption capacity under a load and the like.
  • a higher water-retention capacity a better water-absorption rate
  • a high water-absorption capacity under a load a high water-absorption capacity under a load and the like.
  • the water-retention capacity and the water-absorption rate are in a contradictory relationship with the water-absorption capacity under a load, it is difficult to satisfy a balance between these properties.
  • Patent Document 1 a method of performing reversed phase suspension polymerization using a specific amount of specific macromolecular protective colloid and surfactant
  • Patent Document 2 a method of performing reversed phase suspension polymerization in two or more steps
  • Patent Document 3 a method of performing reversed phase suspension polymerization in the presence of ⁇ -1,3-glucans to obtain a water-absorbent resin and further performing a cross-linking reaction by adding a cross-linking agent to the water-absorbent resin obtained
  • Patent Document 4 a method of performing reversed phase suspension polymerization using a specific amount of persulfate
  • Patent Document 5 a method of performing aqueous polymerization in the presence of phosphorous acid and/or a salt thereof to obtain a water-absorbent resin precursor, and then mixing the water-absorbent resin precursor with a surface cross-linking agent followed by heating
  • water-absorbent resins obtained by these methods do not necessarily satisfy those properties such as the high water-retention capacity, the high water-absorption capacity under a load and the better water-absorption rate as described above, and a room for improvement still remains.
  • the water-absorbent resin may locally absorb a to-be-absorbed liquid around a feeding position of the to-be-absorbed liquid, and the liquid is often blocked because the water-absorbent resin becomes swollen and denser.
  • the diffusibility of the to-be-absorbed liquid into the absorbent material is prevented by the gelatinized water-absorbent resin, and the to-be-absorbed liquid may not be easily distributed throughout the absorbent material, the amount of re-wet of the to-be-absorbed liquid tends to be larger.
  • Patent Document 1 Japanese Unexamined Patent Application Publication No. H06-345819
  • Patent Document 2 Japanese Unexamined Patent Application Publication No. H03-227301
  • Patent Document 3 Japanese Unexamined Patent Application Publication No. H08-120013
  • Patent Document 4 Japanese Unexamined Patent Application Publication No. H06-287233
  • Patent Document 5 Japanese Unexamined Patent Application Publication No. H09-124710
  • An objective of the present invention is to provide a water-absorbent resin capable of improving the diffusibility of a to-be-absorbed liquid to effectively reduce the amount of re-wet when used for an absorbent material.
  • Another objective of the present invention is to provide a method of producing the above water-absorbent resin.
  • a water-absorbent resin obtained by polymerizing a water-soluble ethylenically unsaturated monomer in the presence of an internal-crosslinking agent in which the water-absorption capacity of physiological saline under a load of 4.14 kPa at 120 minutes passed from the start of water absorption is 20 ml/g or more, and the degree of swelling under a load at 30 minutes is 70% or less when the water-absorption capacity of physiological saline under a load of 4.14 kPa at 120 minutes passed from the start of water absorption is taken as a degree of swelling under a load of 100% can increase the diffusibility of a to-be-absorbed liquid in an absorbent material when used in the absorbent material, enabling effective reduction of the amount of re-wet.
  • the present inventors have found that these water-absorbent resins described above can be obtained by a producing method in which reversed phase suspension polymerization of a water-soluble ethylenically unsaturated monomer is performed in a hydrocarbon dispersion medium, the method comprising performing polymerization in the presence of an azo based compound and a peroxide. That is, the present invention provides the followings.
  • the present invention provides a method of producing a water-absorbent resin by performing reversed phase suspension polymerization of a water-soluble ethylenically unsaturated monomer in the presence of an internal-crosslinking agent in a hydrocarbon dispersion medium, the method comprising the steps of: performing polymerization step in the presence of an azo based compound and a peroxide; and performing post-crosslinking step of a hydrous gel-like material obtained from the polymerization using a post-crosslinking agent.
  • the invention also provides the method of producing a water-absorbent resin according to (1), wherein the azo based compound is at least one selected from the group consisting of 2,2′-azobis(2-amidinopropane)dihydrochloride, 2,2′-azobis ⁇ 2-[1-(2-hydroxyethyl)-2-imidazoline 2-yl]propane ⁇ dihydrochloride and 2,2′-azobis[N-(2-carboxyethyl)-2-methylpropione amidine]tetrahydrate.
  • the azo based compound is at least one selected from the group consisting of 2,2′-azobis(2-amidinopropane)dihydrochloride, 2,2′-azobis ⁇ 2-[1-(2-hydroxyethyl)-2-imidazoline 2-yl]propane ⁇ dihydrochloride and 2,2′-azobis[N-(2-carboxyethyl)-2-methylpropione amidine]tetrahydrate.
  • the present invention also provides the method of producing a water-absorbent resin according to (1) or (2), wherein the peroxide is at least one selected from the group consisting of potassium persulfate, ammonium persulfate, sodium persulfate and hydrogen peroxide.
  • the present invention also provides the method of producing a water-absorbent resin according to any one of (1) to (3), wherein the internal-crosslinking agent is at least one selected from the group consisting of (poly)ethylene glycol diglycidyl ether, (poly)propylene glycol diglycidyl ether and (poly)glycerin diglycidyl ether.
  • the present invention provides a water-absorbent resin obtained by performing polymerization of a water-soluble ethylenically unsaturated monomer in the presence of an internal-crosslinking agent, and performing post-crosslinking using a post-crosslinking agent, wherein the water-absorption capacity of physiological saline under a load of 4.14 kPa at 120 minutes passed from the start of water absorption is 20 ml/g or more, and the degree of swelling under a load at 30 minutes is 70% or less when the water-absorption capacity of physiological saline under a load of 4.14 kPa at 120 minutes passed from the start of water absorption is taken as a degree of swelling under a load of 100%.
  • the degree of swelling under a load at a certain time passed is calculated by the following formula:
  • the present invention also provides an absorbent article using an absorbent material comprising the water-absorbent resin according to (5).
  • the present invention can provide a water-absorbent resin in which the diffusibility of a to-be-absorbed liquid can be improved to effectively reduce the amount of re-wet when used for an absorbent material.
  • FIG. 1 shows a pattern diagram illustrating the schematic arrangement of an apparatus for measuring, in a water-absorbent resin, a water-absorption capacity of physiological saline under a load of 4.14 kPa.
  • the method of producing a water-absorbent resin according to the present invention is a method of performing reversed phase suspension polymerization of a water-soluble ethylenically unsaturated monomer in a hydrocarbon dispersion medium in the presence of an internal-crosslinking agent, characterized by comprising the steps of: performing polymerization step in the presence of an azo based compound and a peroxide; and performing post-crosslinking step of a hydrous gel-like material obtained from the polymerization using a post-crosslinking agent.
  • Water-soluble ethylenically unsaturated monomers include, for example, (meth)acrylic acid (“(meth)acry” herein refers to both “acry” and “methacry”. The same shall apply hereinafter) and salts thereof; 2-(meth)acrylamide-2-methylpropanesulfonic acid and salts thereof; nonionic monomers such as (meth) acrylamide, N,N-dimethyl(meth)acrylamide, 2-hydroxyethyl(meth)acrylate, N-methylol(meth)acrylamide, polyethylene glycol mono(meth)acrylate; amino group-containing unsaturated monomers such as N,N-diethylaminoethyl(meth)acrylate, N,N-diethylaminopropyl(meth)acrylate, diethylaminopropyl(meth)acrylamide and quaternary compounds thereof.
  • (meth)acrylic acid (“(meth)acry” herein refers to both
  • water-soluble ethylenically unsaturated monomers (meth)acrylic acid or salts thereof, (meth)acrylamide, N,N-dimethylacrylamide are preferred in view of easy industrial availability, and (meth)acrylic acid and salts thereof are more preferred. Note that these water-soluble ethylenically unsaturated monomers may be used alone or in combination of two or more.
  • acrylic acid and salts thereof are widely used as raw materials for water-absorbent resins, and those materials may be used in which the aforementioned other water-soluble ethylenically unsaturated monomers are copolymerized with these partially neutralized acrylates.
  • a partially neutralized acrylate is preferably used as a main water-soluble ethylenically unsaturated monomer in an amount of 70 to 100 mol % relative to the total amount of water-soluble ethylenically unsaturated monomers.
  • a water-soluble ethylenically unsaturated monomer is preferably dispersed in a hydrocarbon dispersion medium in the state of an aqueous solution, and subjected to reversed phase suspension polymerization.
  • a water-soluble ethylenically unsaturated monomer in the form of an aqueous solution can increase the dispersion efficiency in a hydrocarbon dispersion medium.
  • the concentration of a water-soluble ethylenically unsaturated monomer in the aqueous solution is preferably in a range from 20 mass % to the saturation concentration.
  • the concentration of a water-soluble ethylenically unsaturated monomer is more preferably 55 mass % or less, further preferably 50 mass % or less and further more preferably 45 mass % or less.
  • the concentration of a water-soluble ethylenically unsaturated monomer is more preferably 25 mass % or more, further preferably 28 mass % or more, and further more preferably 30 mass % or more.
  • alkaline neutralizers include alkali metal salts such as sodium hydroxide, sodium carbonate, sodium hydrogen carbonate, potassium hydroxide, potassium carbonate; ammonia and the like. Further, these alkaline neutralizers may be used in the form of an aqueous solution in order to simply neutralization procedures. Note that the aforementioned alkaline neutralizers may be used alone or in combination of two or more.
  • the degree of neutralization of all acid groups in the water-soluble ethylenically unsaturated monomer is preferably 10 to 100 mol %, more preferably 30 to 90 mol %, further preferably 40 to 85 mol % and further more preferably 50 to 80 mol %.
  • Hydrocarbon dispersion media include, for example, aliphatic hydrocarbons having 6 to 8 carbon atoms such as n-hexane, n-heptane, 2-methylhexane, 3-methylhexane, 2,3-dimethylpentane, 3-ethylpentane, n-octane; alicyclic hydrocarbons such as cyclohexane, methylcyclohexane, cyclopentane, methylcyclopentane, trans-1,2-dimethylcyclopentane, cis-1,3-dimethylcyclopentane, trans-1,3-dimethylcyclopentane; aromatic hydrocarbons such as benzene, toluene, xylene and the like.
  • hydrocarbon dispersion media in particular, n-hexane, n-heptane, cyclohexane are suitably used in view of easy industrial availability, stable quality and low cost.
  • These hydrocarbon dispersion media may be used alone or in combination of two or more.
  • examples of a mixture of hydrocarbon dispersion media include commercially available products such as EXXSOL heptane (made by ExxonMobil Corporation: 75 to 85 mass % of heptane and its isomeric hydrocarbons thereof are contained), which can also produce a suitable result.
  • the used amount of the hydrocarbon dispersion medium is preferably 100 to 1500 parts by mass relative to 100 parts by mass of a first-step water-soluble ethylenically unsaturated monomer, and more preferably 200 to 1400 parts by mass.
  • reversed phase suspension polymerization is performed in one step (single step) or in multiple steps such as two or more steps, and the first-step polymerization described above means a polymerization reaction of the first step in single-step polymerization or multiple-step polymerization (The same shall apply hereinafter).
  • a dispersion stabilizer may be used in reversed phase suspension polymerization in order to improve the dispersion stability of a water-soluble ethylenically unsaturated monomer in a hydrocarbon dispersion medium.
  • a surfactant can be used as the dispersion stabilizer.
  • surfactants the followings may be used: for example, sucrose fatty acid ester, polyglycerin fatty acid, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene glycerine fatty acid ester, sorbitol fatty acid ester, polyoxyethylene sorbitol fatty acid ester, polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene castor oil, polyoxyethylene hydrogenated castor oil, alkyl allyl formaldehyde condensed polyoxyethylene ether, polyoxyethylene polyoxypropylene block copolymer, polyoxyethylene polyoxy propyl alkyl ether, polyethylene glycol fatty acid ester, alkyl glucoside, N-alkyl gluconamide, polyoxyethylene fatty acid amide, polyoxyethylene alkylamine, phosphate ester of polyoxyethylene alkyl ether
  • surfactants in particular, sorbitan fatty acid ester, polyglycerin fatty acid ester, and sucrose fatty acid ester are preferably used in view of dispersion stability of monomers. These surfactants may be used alone or in combination of two or more.
  • the used amount of the surfactant is preferably 0.1 to 30 parts by mass relative to 100 parts by mass of a first-step water-soluble ethylenically unsaturated monomer, and more preferably 0.3 to 20 parts by mass.
  • polymeric dispersion agents include, for example, maleic anhydride modified polyethylene, maleic anhydride modified polypropylene, maleic anhydride modified ethylene-propylene copolymer, maleic anhydride modified EPDM (ethylene-propylene-diene-terpolymer), maleic anhydride modified polybutadiene, maleic anhydride-ethylene copolymer, maleic anhydride-propylene copolymer, maleic anhydride-ethylene-propylene copolymer, maleic anhydride-butadiene copolymer, polyethylene, polypropylene, ethylene-propylene copolymer, oxidized polyethylene, oxidized polypropylene, oxidized ethylene-propylene copolymer, ethylene-acrylate copolymer, ethyl cellulose, ethyl hydroxyethyl cellulose and the like
  • maleic anhydride modified polyethylene maleic anhydride modified polypropylene, maleic anhydride modified ethylene-propylene copolymer, maleic anhydride-ethylene copolymer, maleic anhydride-propylene copolymer, maleic anhydride-ethylene-propylene copolymer, polyethylene, polypropylene, ethylene-propylene copolymer, oxidized polyethylene, oxidized polypropylene, oxidized ethylene-propylene copolymer are preferably used.
  • These polymeric dispersion agents may be used alone or in combination of two or more.
  • the used amount of the polymeric dispersion agent is preferably 0.1 to 30 parts by mass relative to 100 parts by mass of a first-step water-soluble ethylenically unsaturated monomer, and more preferably 0.3 to 20 parts by mass.
  • the internal-crosslinking agents include, for example, unsaturated polyesters obtained by allowing polyols, for example, diols and triols such as (poly)ethylene glycol (“(poly)” means that the prefix “poly” is optional.
  • polyglycidyl compounds is preferably used, and diglycidyl compounds are more preferably used, and (poly)ethylene glycol diglycidyl ether, (poly)propylene glycol diglycidyl ether, (poly)glycerin diglycidyl ether are further preferably used.
  • These internal-crosslinking agents may be used alone or in combination of two or more.
  • the used amount of the internal-crosslinking agent is preferably 0.000001 to 0.02 mol relative to 1 mol of a water-soluble ethylenically unsaturated monomer, more preferably 0.00001 to 0.01 mol, further preferably 0.00001 to 0.005 mol and further more preferably 0.00005 to 0.002 mol.
  • the phrase “in the presence of an azo based compound and a peroxide” does not necessarily means that the azo based compound and the peroxide are coexistent at the beginning of a polymerization reaction, but means that one compound is present before a monomer conversion ratio by radical cleavage due to the other compound becomes 10% or more.
  • the both are preferably present in an aqueous solution containing a monomer before the start of the polymerization reaction.
  • an azo based compound and a peroxide may be added to a polymerization reaction system via different flow channels or may be sequentially added to the polymerization reaction system via the same flow channel. Note that an azo based compound and a peroxide to be used may be in the form of powder or an aqueous solution.
  • Azo based compounds include, for example, those azo based compounds such as 1- ⁇ (1-cyano-1-methylethyl)azo ⁇ formamide, 2,2′-azobis[2-(N-phenyl amidino)propane]dihydrochloride, 2,2′-azobis ⁇ 2-[N-(4-chlorophenyl)amidino]propane ⁇ dihydrochloride, 2,2′-azobis ⁇ 2-[N-(4-hydroxyphenyl)amidino]propane ⁇ dihydrochloride, 2,2′-azobis[2-(N-benzyl amidino)propane]dihydrochloride, 2,2′-azobis[2-(N-allyl amidino)propane]dihydrochloride, 2,2′-azobis(2-amidinopropane)dihydrochloride, 2,2′-azobis ⁇ 2-[N-(2-hydroxyethyl)amidino]propane ⁇ dihydrochloride, 2,2′-
  • 2,2′-azobis(2-amidinopropane)dihydrochloride, 2,2′-azobis ⁇ 2-[1-(2-hydroxyethyl)-2-imidazoline-2-yl]propane ⁇ dihydrochloride, 2,2′-azobis[N-(2-carboxyethyl)-2-methylpropione amidine]tetrahydrate are preferred.
  • These azo based compounds may be used alone or in combination of two or more.
  • Peroxides include, for example, persulfates such as potassium persulfate, ammonium persulfate, sodium persulfate; peroxides such as methyl ethyl ketone peroxide, methyl isobutyl ketone peroxide, di-t-butyl peroxide, t-butyl cumyl peroxide, t-butyl peroxyacetate, t-butyl peroxy isobutyrate, t-butyl peroxy pivalate, hydrogen peroxide.
  • persulfates such as potassium persulfate, ammonium persulfate, sodium persulfate
  • peroxides such as methyl ethyl ketone peroxide, methyl isobutyl ketone peroxide, di-t-butyl peroxide, t-butyl cumyl peroxide, t-butyl peroxyacetate, t-butyl peroxy isobutyrate
  • potassium persulfate, ammonium persulfate, sodium persulfate, hydrogen peroxide are preferably used, and further, potassium persulfate, ammonium persulfate, sodium persulfate are more preferably used.
  • potassium persulfate, ammonium persulfate, sodium persulfate are more preferably used.
  • These peroxides may be used alone or in combination of two or more.
  • the used amount of an azo based compound and a peroxide is preferably 0.00005 mol or more relative to 1 mol of a water soluble ethylenically unsaturated monomer, more preferably 0.0001 mol or more. Further, the used amount is preferably 0.005 mol or less relative to 1 mol of a water-soluble ethylenically unsaturated monomer, and more preferably 0.001 mol or less.
  • the proportion of the azo based compound is preferably 40 mass % or more relative to the total used amount of the azo based compound and the peroxide, more preferably 50 mass % or more, further preferably 60 mass % or more and further more preferably 70 mass %.
  • the proportion of an azo based compound is preferably 95 mass % or less relative to the total used amount of the azo based compound and the peroxide, more preferably 90 mass % or less, further preferably 85 mass % and further more preferably 80 mass % or less.
  • the range of the mass ratio (azo based compound: peroxide) is preferably 8:12 to 19:1.
  • ком ⁇ онент may be added to a water-soluble ethylenically unsaturated monomer to perform reversed phase suspension polymerization, if desired.
  • chain transfer agents, thickeners, other various additives and the like may be added.
  • a water-soluble ethylenically unsaturated monomer may be polymerized in the presence of a chain transfer agent in order to control the water-absorption performance of the water-absorbent resin.
  • Chain transfer agents include, for example, thiols such as ethanethiol, propanethiol, dodecanethiol; thiolic acids such as thioglycolic acid, thiomalic acid, dimethyldithiocarbamic acid, diethyldithiocarbamic acid or salts thereof; secondary alcohols such as isopropanol; phosphorous acid compounds, for example, phosphorous acid, normal salts of phosphorous acid such as disodium phosphite, dipotassium phosphite, diammonium phosphite, acid salts of phosphorous acid such as sodium hydrogen phosphite, potassium hydrogen phosphite, ammonium hydrogen phosphite, and the like; phosphoric acid compound, for example, phosphoric acid, normal salts of phosphoric acid such as sodium phosphate, potassium phosphate, ammonium phosphate, acid salts of phosphoric acid such as sodium dihydrogen
  • the used amount of a chain transfer agent is preferably 0.00001 to 0.0005 mol relative to 1 mol of a water-soluble ethylenically unsaturated monomers, more preferably 0.000025 to 0.00012 mol.
  • a thickener may be added to an aqueous solution containing a water-soluble ethylenically unsaturated monomer to perform reversed phase suspension polymerization.
  • a thickener By adding a thickener to adjust the viscosity of an aqueous solution as described above, the median particle diameter obtained by reversed phase suspension polymerization may also be controlled.
  • hydroxyethyl cellulose, hydroxypropyl cellulose, methyl cellulose, carboxymethyl cellulose, polyacrylic acid, (partially) neutralized polyacrylic acid, polyethylene glycol, polyacrylamide, polyethyleneimine, dextrin, sodium alginate, polyvinyl alcohol, polyvinyl pyrrolidone, polyethylene oxide and the like can be used. Note that the following tends to be observed: in a case where the stirring speeds at the time of polymerization are the same, the higher is the viscosity of an aqueous solution of a water-soluble ethylenically unsaturated monomer, the larger is the median particle diameter of the resulting particles.
  • an aqueous monomer solution containing a water-soluble ethylenically unsaturated monomer is dispersed in a hydrocarbon dispersion medium, for example, in the presence of a dispersion stabilizer.
  • a dispersion stabilizer a surfactant and/or a polymeric dispersion agent
  • a surfactant and/or a polymeric dispersion agent may be added either before or after the aqueous monomer solution is dispersed as long as they are added before the start of a polymerization reaction.
  • polymerization is performed after an aqueous monomer solution is dispersed in a hydrocarbon dispersion medium in which a polymeric dispersion agent has been dispersed, and then a surfactant is further dispersed.
  • reversed phase suspension polymerization can be performed as described above in a single step or multiple steps such as two or more steps. Further, in view of increasing productivity, it is more preferably performed in 2 to 3 steps.
  • a water-soluble ethylenically unsaturated monomer may be added to the reaction mixture obtained in the first-step polymerization reaction, and mixed to perform a second-step reversed phase suspension polymerization as in the first step.
  • reversed phase suspension polymerization is preferably performed by adding, in addition to a water-soluble ethylenically unsaturated monomer, an internal-crosslinking agent, an azo compound and a peroxide described above within the aforementioned range of the molar ratio of each component relative to the water-soluble ethylenically unsaturated monomer on the basis of the amount of the water-soluble ethylenically unsaturated monomer to be added in the reversed phase suspension polymerization in each step of the second step and later steps.
  • polymerization is also preferably performed in the presence of an azo based compound and a peroxide in polymerization of the second step and later steps.
  • the reaction temperature for a polymerization reaction is preferably 20 to 110° C., more preferably 40 to 90° C. from the viewpoint that economy may be improved by allowing rapid progress of a polymerization to reduce a polymerization time, and polymerization heat may be easily removed to perform a smooth reaction. Further, the reaction time is preferably 0.5 to 4 hours.
  • post-crosslinking of a hydrous gel-like material obtained by polymerizing a water soluble ethylenically unsaturated monomer which has an internal-crosslinking structure is performed using a post-crosslinking agent (post-crosslinking reaction).
  • This post-crosslinking reaction is preferably performed in the presence of a post-crosslinking agent after the polymerization of a water soluble ethylenically unsaturated monomer.
  • a water-absorbent resin By performing a post-crosslinking reaction of a hydrous gel-like material having an internal-crosslinking structure after the polymerization to increase a crosslinking density near a surface of a water-absorbent resin as described above, a water-absorbent resin can be obtained which has various enhanced properties such as a water-absorption capacity under a load and a water-absorption rate.
  • Post-crosslinking agents can include those compounds having two or more reactive functional groups. They include, for example, polyols such as ethylene glycol, propylene glycol, 1,4-butanediol, trimethylolpropane, glycerin, polyoxyethylene glycol, polyoxypropylene glycol, polyglycerin; polyglycidyl compounds such as (poly)ethylene glycol diglycidyl ether, (poly)glycerin diglycidyl ether, (poly)glycerin triglycidyl ether, trimethylolpropane triglycidyl ether, (poly)propylene glycol polyglycidyl ether, (poly)glycerol polyglycidyl ether; haloepoxy compounds such as epichlorohydrin, epibromhydrin, a-methyl epichlorohydrin; isocyanate compounds such as 2,4-tolylene diisocyanate, hexamethylene di
  • post-crosslinking agents preferred are polyglycidyl compounds such as (poly)ethylene glycol diglycidyl ether, (poly)glycerin diglycidyl ether, (poly)glycerol triglycidyl ether, trimethylolpropane triglycidyl ether, (poly)propylene glycol polyglycidyl ether, (poly)glycerol polyglycidyl ether.
  • These post-crosslinking agents may be used alone or in combination of two or more.
  • the used amount of a post-crosslinking agent is preferably 0.00001 to 0.01 mol relative to 1 mol of the total amount of a water-soluble ethylenically unsaturated monomer used for polymerization, more preferably 0.00005 to 0.005 mol and further preferably 0.0001 to 0.002 mol.
  • the post-crosslinking agent may be added as it is or as an aqueous solution.
  • a post-crosslinking agent may also be added as a solution in which a hydrophilic organic solvent is used as a solvent, if desired.
  • Hydrophilic organic solvents include, for example, lower alcohols such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol; ketones such as acetone, methyl ethyl ketone; ethers such as diethyl ether, dioxane, tetrahydrofuran; amides such as N,N-dimethylformamide; sulfoxides such as dimethyl sulfoxide. These hydrophilic organic solvents may be used alone or in combination of two or more, or may be used as a mixed solvent with water.
  • a post-crosslinking agent may be added after the polymerization reaction of water-soluble ethylenically unsaturated monomer has been almost completed, and it is preferably added in the presence of water in the range of 1 to 400 parts by mass relative to 100 parts by mass of a water-soluble ethylenically unsaturated monomer, more preferably added in the presence of water in the range of 5 to 200 parts by mass, further preferably added in the presence of water in the range of 10 to 100 parts by mass and further more preferably added in the presence of water in the range of 20 to 60 parts by mass.
  • the amount of water means the total amount of a water content in a reaction system and a water content used if desired when adding a post-crosslinking agent.
  • the reaction temperature in the post-crosslinking reaction is preferably 50 to 250° C., more preferably 60 to 180° C., further preferably 60 to 140° C. and further more preferably 70 to 120° C. Further, the reaction time for the post-crosslinking reaction is preferably for 1 to 300 minutes, and more preferably for 5 to 200 minutes.
  • the method of producing a water-absorbent resin according to the present invention may comprise a drying step of removing water, a hydrocarbon dispersion medium and the like using distillation by applying energy such as heat from the outside after performing the aforementioned reversed phase suspension polymerization.
  • a drying step of removing water, a hydrocarbon dispersion medium and the like using distillation by applying energy such as heat from the outside after performing the aforementioned reversed phase suspension polymerization When performing dehydration of a hydrous gel after reversed phase suspension polymerization, a system in which the hydrous gel is dispersed in a hydrocarbon dispersion medium is heated to temporarily evaporate water and the hydrocarbon dispersion medium from the system by azeotropic distillation. At this time, only the hydrocarbon dispersion medium evaporated is allowed to return into the system, enabling continuous azeotropic distillation.
  • the temperature in the system during the drying treatment is maintained at or below the azeotropic temperature with the hydrocarbon dispersion medium. Therefore this is preferred in view of that, for example, the resin is less susceptible to deterioration.
  • Water and the hydrocarbon dispersion medium is continuously evaporated away to obtain particles of a water-absorbent resin.
  • the drying treatment may be performed by distillation under ordinary pressure or under a reduced pressure. Further, the drying treatment may be performed under a gas flow of nitrogen and the like in view of increased drying efficiency.
  • a drying temperature is preferably 70 to 250° C., more preferably 80 to 180° C., further preferably 80 to 140° C. and further more preferably 90 to 130° C.
  • a drying temperature is preferably 40 to 160° C., more preferably 50 to 110° C.
  • the drying step is performed by distillation as described above after the post-crosslinking step.
  • the post-crosslinking step and the drying step may be performed simultaneously.
  • additives such as chelating agents, reducing agents, oxidizing agents, antibacterial agents, deodorizing agents may be added to a water-absorbent resin after polymerization, during or after drying.
  • the water-absorbent resin according to the present invention can be obtained by polymerizing a water-soluble ethylenically unsaturated monomer in the presence of an internal-crosslinking agent, and performing post-crosslinking with a post-crosslinking agent, and characterized by that the water-absorption capacity of physiological saline under a load of 4.14 kPa at 120 minutes passed from the start of water absorption is 20 ml/g or more.
  • the water-absorption capacity of physiological saline under a load of 4.14 kPa at 120 minutes passed from the start of water absorption is 20 ml/g or more, preferably 22 ml/g or more, more preferably 24 ml/g, and further preferably 26 ml/g. Further the water-absorption capacity of physiological saline under a load of 4.14 kPa at 120 minutes passed from the start of water absorption is preferably 50 ml/g or less, and more preferably 40 ml/g or less.
  • the water-absorbent resin according to the present invention is characterized by that the degree of swelling under a load at 30 minutes is 70% or less.
  • the degree of swelling under a load after a certain time has passed means a proportion of [the water-absorption capacity of physiological saline under a load of 4.14 kPa after a certain time has passed (for example, after 30 minutes)] relative to [the water-absorption capacity of physiological saline under a load of 4.14 kPa at 120 minutes passed from the start of water absorption], and may be calculated by the following formula.
  • a water-absorbent resin showing a degree of swelling under a load at 30 minutes of 70% or less means that it will slowly absorb a liquid (to-be-absorbed liquid) under a load over a long time period at a predetermined water-absorption capacity.
  • the degree of swelling under a load at 30 minutes is preferably 65% or less, more preferably 60% or less, and further preferably 55% or less.
  • the degree of swelling under a load at 30 minutes is preferably 15% or more, more preferably is 20% or more, and further preferably 25% or more, and further more preferably 30% or more.
  • the degree of swelling under a load at 240 minutes is preferably 110% or more in order to further enhance effects when used for an absorbent material.
  • the water-retention capacity of physiological saline after 120 minutes is preferably 30 to 60 g/g, more preferably 35 to 55 g/g, further preferably 37 to 53 g/g and further more preferably 40 to 50 g/g.
  • a water-retention capacity of physiological saline represents a degree of a liquid absorption capacity of a water-absorbent resin per unit mass.
  • the water-retention degree of swelling after 15 minutes is preferably less than 95%.
  • the water-retention degree of swelling after a certain time has passed is a proportion of particles of [the water-retention capacity of physiological saline after a certain time has passed (for example, after 15 minutes)] relative to [the water-retention capacity of physiological saline after 120 minutes], and may be calculated by the following formula.
  • the water-absorbent resin according to the present invention preferably has a median particle diameter of 200 to 600 ⁇ m, more preferably 250 to 500 ⁇ m, further preferably 300 to 450 ⁇ m and further more preferably 300 to 400 ⁇ m.
  • the mass proportion of particles from 150 to 850 ⁇ m relative to the whole proportion is preferably 85 mass % or more, and more preferably 90 mass % or more. Further, the mass proportion of particles from 300 to 400 ⁇ m relative to the whole proportion is preferably 20 mass % or more, more preferably 25 mass % or more, and further preferably 30 mass % or more.
  • particles of water-absorbent resin may be in a form where each comprises a single particle, or may be in a form where fine particles (primary particles) are agglomerated (secondary particles).
  • Forms of the primary particles include a substantially spherical form, an irregular fractured form, a plate-like form and the like.
  • primary particles When primary particles are manufactured by reversed phase suspension polymerization, they include a substantially spherical single particle form having a smooth surface such as a true spherical shape, an elliptically spherical shape. Then, the flowability as powder is high because primary particles in such forms have a smooth surface. Further, agglomerated particles are not easily destroyed upon impact, and thus a water-absorbent resin having high particle strength can be formed because agglomerated particles tend to be more densely packed.
  • the water-retention capacity of physiological saline, the water-absorption capacity of physiological saline under a load of 4.14 kPa and the median particle diameter of the aforementioned water-absorbent resin can either be evaluated by the evaluation test methods described in Examples below.
  • an additive may be blended depending on the purposes in order to provide various preferred properties on the resulting water-absorbent resin.
  • additives include inorganic powders, surfactants, oxidizing agents, reducing agents, metal chelating agents, radical chain inhibitors, anti-oxidizing agents, antibacterial agents, deodorizing agents and the like.
  • the flowability of a water-absorbent resin can be improved by adding 0.05 to 5 parts by mass of amorphous silica as an inorganic powder relative to 100 parts by mass of the water-absorbent resin.
  • the water-absorbent resin according to the present invention may form an absorbent material for use in, for example, hygienic materials such as sanitary goods and disposable diapers, and may suitably be used in absorbent articles comprising absorbent materials.
  • an absorbent material in which a water-absorbent resin is used comprises, for example, the water-absorbent resin and a hydrophilic fiber.
  • the structures of the absorbent material include a dispersion mixture obtained by mixing a water-absorbent resin and a hydrophilic fiber to give a uniform composition, a sandwich structure in which a water-absorbent resin is sandwiched between layered hydrophilic fibers, a structure in which a water-absorbent resin and a hydrophilic fiber is wrapped in tissue, and the like.
  • adhesive binder such as thermal adhesive synthetic fibers, hot melt adhesives, adhesive emulsions for increasing the shape retention capability of an absorbent material may be included in the absorbent material.
  • the content of a water-absorbent resin in an absorbent material is preferably 5 to 95 mass %, more preferably 20 to 90 mass % and further preferably 30 to 80 mass %.
  • Hydrophilic fibers include cellulose fibers prepared from wood such as cotton-like pulp, mechanical pulp, chemical pulp, semi-chemical pulp; artificial cellulose fibers such as rayon, acetate; fibers comprising synthetic resin such as hydrophilized polyamide, polyester and polyolefine.
  • an absorbent material in which a water-absorbent resin is used can be held between a liquid permeable sheet (a top sheet) through which a liquid can permeate and a liquid impermeable sheet (a back sheet) through which a liquid cannot permeate to give an absorbent article.
  • the liquid permeable sheet is arranged on the side to be in contact with the body while the liquid impermeable sheet is arranged opposite to the side to be in contact with the body.
  • Liquid permeable sheets include nonwoven of an air through type, a span bond type, a chemical bond type, a needle punch type and the like comprising fiber such as polyethylene, polypropylene, polyester, etc. and porous synthetic resin sheets and the like. Further, liquid impermeable sheets include synthetic resin films comprising a resin such as polyethylene, polypropylene, polyvinyl chloride and the like.
  • Water-absorbent resins obtained from Examples 1, 2 and 3 and Comparative Examples 1 and 2 below were subjected to various tests described below for evaluation. In the followings, each evaluation test method will be described.
  • a cotton bag (cotton broadcloth No. 60, horizontal 100 mm ⁇ vertical 200 mm) into which 2.0 g of a water-absorbent resin was weighed out was placed into a 500 mL beaker.
  • 500g of 0.9 mass % aqueous sodium chloride (physiological saline) was poured in one portion so that lumps were not formed.
  • the upper part of the cotton bag was then closed with a rubber band, and stood for a predetermined time to allow the water-absorbent resin to swell.
  • the cotton bag was dehydrated for 1 minute using a dehydrator (made by KOKUSAN Co., Ltd., Product number: H-122) configured such that the centrifugal force would be 167 G. Then the mass Wa (g) of the cotton bag containing swollen gel after dehydration was measured. Similar procedures were performed without adding a water-absorbent resin, and the empty mass Wb (g) of the wet cotton bag was measured, and a water-retention capacity was calculated by the following formula. Note that in this Example, the water-absorbent resin was allowed to swell for each standing time of 15 minutes, 30 minutes, 60 minutes, 120 minutes, and a water-retention capacity was measured after each standing time.
  • a water-absorption capacity of physiological saline under a load of 4.14 kPa of a water-absorbent resin was measured using a measurement apparatus X.
  • a schematic arrangement of the measurement apparatus X is shown in FIG. 1 .
  • the measurement apparatus X shown in FIG. 1 comprises a buret part 1 , a conduit 2 , a measurement stage 3 , a measurement part 4 placed on the measurement stage 3 .
  • a rubber stopper 14 is connected to the upper part of a buret 10
  • an air introducing pipe 11 and a cock 12 is connected to the lower part of the buret 10 .
  • a cock 13 is attached to the upper part of the air introducing pipe 11 .
  • a conduit 2 connects the buret part 1 and the measurement stage 3 .
  • the diameter of the conduit 2 is 6 mm.
  • the measurement stage 3 has a hole with a diameter of 2 mm at the center, to which the conduit 2 is connected.
  • the measurement part 4 is provided with a cylinder 40 and a nylon mesh 41 patched on the bottom of the cylinder 40 , as well as a weight 42 .
  • the inner diameter of the cylinder 40 is 2.0 cm.
  • the nylon mesh 41 is formed as 200 mesh (75 ⁇ m openings). Further, it is configured such that a predetermined amount of a water-absorbent resin 5 is uniformly distributed on the nylon mesh 41 .
  • the weight 42 has a diameter of 1.9 cm and a mass of 119.6 g. The weight 42 is to be placed on the water-absorbent resin 5 to uniformly apply a load of 4.14 kPa to the water-absorbent resin 5 .
  • the cock 12 and the cock 13 at the buret part 1 were closed, and then physiological saline adjusted to 25° C. was introduced into the buret 10 from the top. Subsequently, the top of the buret was plugged with the rubber stopper 14 , and then the cock 12 and the cock 13 at the buret part 1 were opened. Next, the height of the measurement stage 3 was adjusted so that the tip of the conduit 2 at the center of the measurement stage 3 is leveled with the air inlet of the air introducing pipe 11 .
  • the water-absorbent resin 5 was uniformly distributed on the nylon mesh 41 in the cylinder 40 , and then the weight 42 was placed on that water-absorbent resin 5 .
  • the measurement part 4 was arranged so that its center coincided with the conduit inlet at the center of the measurement stage 3 .
  • the amount of reduced physiological saline in the buret 10 (the amount of physiological saline absorbed by the water-absorbent resin 5 ) We (mL) was continuously measured from the time point when the water-absorbent resin 5 started to absorb water. At each passing time of 30 minutes, 60 minutes, 120 minutes, and 240 minutes from the start of water absorption, a water-absorption capacity of physiological saline under a load of 4.14 kPa of the water-absorbent resin was calculated by the following formula.
  • JIS standard sieves were combined in the following order from the top: a sieve of 850 ⁇ m openings, a sieve of 600 ⁇ m openings, a sieve of 500 ⁇ m openings, a sieve of 400 ⁇ m openings, a sieve of 300 ⁇ m openings, a sieve of 250 ⁇ m openings, a sieve 150 ⁇ m openings and a receiving tray.
  • a water-absorbent resin in an amount of 50 g was introduced on the top of the combined sieves, and then shaken for 20 minutes using a ro-tap shaker for classification. After classification, the mass of the water-absorbent resin which remained in each sieve was calculated as a mass proportion of particles relative to the total mass to obtain a particle size distribution. By integrating the amount on each sieve from the one having the largest particle diameter in this particle size distribution, the relationship between the sieve openings and the integrated value of the mass proportion of particles of the water-absorbent resin which remained in the sieves was plotted on logarithmic probability paper. By connecting the plots on the probability paper with a straight line, a particle diameter corresponding to 50 mass % in the integrated mass proportion of particles is taken as the median particle diameter.
  • the mass proportion of particles from 300 to 400 ⁇ m in the total water-absorbent resin is a mass proportion of particles of a water-absorbent resin which remained in the sieve with 300 ⁇ m openings relative to the whole proportion in the aforementioned measurements.
  • the mass proportion of particles from 150 to 850 ⁇ m in the total water-absorbent resin is a value obtained by summing the mass proportion of particles of the water-absorbent resin which remained in sieves with openings of 150 ⁇ m, 250 ⁇ m, 300 ⁇ m, 400 ⁇ m, 500 ⁇ m, and 600 ⁇ m.
  • the absorbent article was prepared by arranging a polyethylene-polypropylene air-through porous liquid permeable sheet on the upper surface of the absorbent material, the sheet having a basis weight of 22 g/m 2 and the same size as the absorbent material, and arranging a polyethylene impermeable sheet of the same size and the same basis weight on the lower surface of the absorbent material.
  • the absorbent article was first placed on a horizontal stage. On the center portion of the absorbent article, a measurement apparatus incorporating a liquid pouring cylinder having an inside diameter of 3 cm was placed, and 50 mL of the test liquid was poured into the cylinder at a time and a stopwatch was used to measure the time until the test liquid was made to disappear completely, with the result that the time was assumed to be the first permeation time (in seconds).
  • the cylinder described above was removed, the absorbent article was stored in the present state and both when 30 minutes had elapsed and when 60 minutes had elapsed since the start of the first round of the pouring of the test liquid, the measurement apparatus was used in the position as in the first round, and the same operation was performed, with the result that the second and third permeation times (in seconds) were measured.
  • the total time of the first to third rounds was assumed to be the total permeation time. It is said that as the permeation time is shorter, the absorbent article was more preferable.
  • the dimension (cm) of spread of the absorbent article in the longitudinal direction into which the test liquid is penetrated was measured. Note that values below the decimal point were rounded off.
  • a 2L cylindrical round-bottom separable flask with an inner diameter of 110 mm was prepared which was equipped with a reflux condenser, a dropping funnel, a nitrogen gas-introducing tube and stirrer having stirring blades compound of two sets of 4 inclined paddle blades with a blade diameter of 50 mm.
  • 300 g of n-heptane was introduced as a hydrocarbon dispersion medium, and 0.74 g of maleic anhydride modified ethylene-propylene copolymer (made by Mitsui Chemicals, Inc., High Wax 1105A) as a polymeric dispersion agent was added, and heat-dissolved with stirring, and then cooled to 50° C.
  • hydroxylethyl cellulose made by Sumitomo Seika Chemicals Co., Ltd., HEC AW-15F
  • 0.092 g 0.339 mmol
  • 2,2′-azobis(2-amidinopropane)dihydrochloride as an azo based compound
  • 0.037 g 0.137 mmol
  • potassium persulfate as a peroxide
  • 0.010 g 0.058 mmol
  • ethylene glycol diglycidyl ether as an internal-crosslinking agent
  • 43.8 g of ion exchange water were added and dissolved to prepare an aqueous monomer solution.
  • aqueous monomer solution prepared as described above was added to a separable flask, and stirred for 10 minutes.
  • 7.4 g of a surfactant solution in which 0.74 g of HLB3 sucrose stearic acid ester (made by Mitsubishi-Kagaku Foods Corporation, Ryoto sugar ester S-370) as a surfactant was heat-dissolved in 6.66 g of n-heptane was further added, and the atmosphere in the system was thoroughly replaced with nitrogen with stirring.
  • the flask was immersed into a 70° C. water bath to raise temperature, and a first-step polymerization was performed for 60 minutes to obtain a first-step polymerized slurry.
  • the reaction liquid was heated to 125° C. in an oil bath, and 239 g of water was removed from the system by refluxing n-heptane in azeotropic distillation of n-heptane and water. Then, 4.42 g (0.51 mmol) of 2 mass % aqueous solution of ethylene glycol diglycidyl ether was added as a post-crosslinking agent, and maintained at 80° C. for 2 hours. Subsequently, drying was performed by evaporating n-heptane, and then a dried resin was obtained.
  • This dried resin was mixed with 0.3 mass % of amorphous silica (made by Evonik Degussa Japan, Inc., Carplex #80), and allowed to pass through a sieve with 1000 ⁇ m openings to obtain 231.2 g of a water-absorbent resin in a form of agglomerated spherical particles.
  • This water-absorbent resin was evaluated in accordance with the various test methods as described above.
  • the mass proportion of particles from 150 to 850 ⁇ m relative to the whole proportion was 92 mass %, and the mass proportion of particles from 300 to 400 ⁇ m relative to the whole proportion was 32 mass %.
  • Example 2 the same was performed as in Example 1 except that after the second-step polymerization, 236 g of water was removed from the system by refluxing n-heptane in azeotropic distillation of n-heptane and water. Thereby, obtained was 234.1 g of a water-absorbent resin having a different water-retention capacity from the water-absorbent resin obtained in Example 1. This water-absorbent resin was evaluated in accordance with the various test methods as described above.
  • the mass proportion of particles from 150 to 850 ⁇ m relative to the whole proportion was 94 mass %, and the mass proportion of particles from 300 to 400 ⁇ m relative to the whole proportion was 36 mass %.
  • Example 3 the same was performed as in Example 1 except that the addition amount of an internal-crosslinking agent ethylene glycol diglycidyl ether to be dissolved in the first-step aqueous monomer solution was 0.020 g (0.116 mmol), and after the second-step polymerization, 254 g of water was removed from the system by refluxing n-heptane in azeotropic distillation of n-heptane and water. Thereby, obtained was 232.9 g of a water-absorbent resin which differed from the water-absorbent resin obtained in Example 1 in that a different internal-crosslinking agent was used. This water-absorbent resin way was evaluated in accordance with the various test methods as described above.
  • the mass proportion of particles from 150 to 850 ⁇ m relative to the whole proportion was 95 mass %, and the mass proportion of particles from 300 to 400 ⁇ m relative to the whole proportion was 33 mass %.
  • a 2L cylindrical round-bottom separable flask with an inner diameter of 110 mm was prepared which was equipped with a reflux condenser, a dropping funnel, a nitrogen gas-introducing tube and stirrer having stirring blades compound of two sets of 4 inclined paddle blades with a blade diameter of 50 mm.
  • n-heptane as a hydrocarbon dispersion medium
  • 0.74 g of maleic anhydride modified ethylene-propylene copolymer made by Mitsui Chemicals, Inc., High Wax 1105A
  • hydroxylethyl cellulose made by Sumitomo Seika Chemicals Co., Ltd., HEC AW-15F
  • 0.074 g (0.274 mmol) of potassium persulfate as a peroxide 0.010 g (0.058 mmol) of ethylene glycol diglycidyl ether as an internal-crosslinking agent and 43.8 g of ion exchange water were added and dissolved to prepare an aqueous monomer solution.
  • aqueous monomer solution prepared as described above was added to a separable flask, and stirred for 10 minutes.
  • 7.4 g of a surfactant solution in which 0.74 g of HLB3 sucrose stearic acid ester (made by Mitsubishi-Kagaku Foods Corporation, Ryoto sugar ester S-370) as surfactant was heat-dissolved in 6.66 g of n-heptane was further added, and the atmosphere in the system was thoroughly replaced with nitrogen with stirring.
  • the flask was immersed into a 70° C. water bath to raise temperature, and a first-step polymerization was performed for 60 minutes to obtain a first-step polymerized slurry.
  • the reaction liquid was heated to 125° C. in an oil bath, and 257 g of water was removed from the system by refluxing n-heptane in azeotropic distillation of n-heptane and water. Then, 4.42 g (0.51 mmol) of 2 mass % aqueous solution of ethylene glycol diglycidyl ether was added as a post-crosslinking agent, and maintained at 80° C. for 2 hours. Subsequently, drying was performed by evaporating n-heptane to obtain a dried resin.
  • This dried resin was mixed with 0.3 mass % of amorphous silica (made by Evonik Degussa Japan, Inc., Carplex #80), and allowed to pass through a sieve with 1000 ⁇ m openings to obtain 228.2 g of a water-absorbent resin in a form of agglomerated spherical particles.
  • This water-absorbent resin was evaluated in accordance with the various test methods as described above.
  • the mass proportion of particles from 150 to 850 ⁇ m relative to the whole proportion was 94 mass %, and the mass proportion of particles from 300 to 400 ⁇ m relative to the whole proportion was 33 mass %.
  • Comparative Example 2 after a predetermined monomer conversion ratio was achieved in the polymerization performed by adding an azo based compound, a peroxide was added to perform reversed phase suspension polymerization for production of a water-absorbent resin.
  • a 2L cylindrical round-bottom separable flask with an inner diameter of 110 mm was prepared which was equipped with a reflux condenser, a dropping funnel, a nitrogen gas-introducing tube and stirrer having stirring blades compound of two sets of 4 inclined paddle blades with a blade diameter of 50 mm.
  • 300 g of n-heptane as a hydrocarbon dispersion medium was introduced and 0.74 g of maleic anhydride modified ethylene-propylene copolymer (made by Mitsui Chemicals, Inc., High Wax 1105A) as a polymeric dispersion agent was added, and heat-dissolved with stirring. Then it was cooled to 50° C.
  • aqueous monomer solution prepared as described above was added to a separable flask, and stirred for 10 minutes.
  • 7.4 g of a surfactant solution in which 0.74 g of HLB3 sucrose stearic acid ester (made by Mitsubishi-Kagaku Foods Corporation, Ryoto sugar ester S-370) as a surfactant was heat-dissolved in 6.66 g of n-heptane was further added, and the atmosphere in the system was thoroughly replaced with nitrogen with stirring.
  • the flask was immersed into a 70° C. water bath to raise temperature, and then a first-step polymerization was performed for 60 minutes.
  • the system after cooled to 25° C. was taken as the 50% monomer conversion ratio, and an aqueous solution in which 0.037 g (0.137 mmol) of potassium persulfate as a peroxide was dissolved in 1.23 g of ion exchange water was added.
  • aqueous monomer solution As an internal-crosslinking agent, 0.010 g (0.058 mmol) of ethylene glycol diglycidyl ether was added to the other aqueous monomer solution, and dissolved to prepare a second-step aqueous monomer solution.
  • the reaction liquid was heated to 125° C. in an oil bath, and 237 g of water was removed from the system by refluxing n-heptane in azeotropic distillation of n-heptane and water. Then, 4.42 g (0.51 mmol) of 2 mass % aqueous solution of ethylene glycol diglycidyl ether was added as a post-crosslinking agent, and maintained at 80° C. for 2 hours. Subsequently, drying was performed by evaporating n-heptane to obtain a dried resin.
  • This dried resin was mixed with 0.3 mass % of amorphous silica (Evonik Degussa Japan, Inc., Carplex #80), and allowed to pass through a sieve with 1000 ⁇ m openings to obtain 199.5 g of a water-absorbent resin in a form of agglomerated spherical particles.
  • This water-absorbent resin was evaluated in accordance with the various test methods as described below.
  • the mass proportion of particles from 150 to 850 ⁇ m relative to the whole proportion was 93 mass %, and the mass proportion of particles from 300 to 400 ⁇ m relative to the whole proportion was 28 mass %.
  • Table 1 shown in Table 1 below are the water-retention capacities (measured values) of physiological saline after corresponding standing times when allowed to stand to absorb water for 15 minutes, 30 minutes, 60 minutes, and 120 minutes, and the water-retention degrees of swelling (%) which is calculated by the following formula based on the analytical value of its water-retention capacity when the water-retention capacity of a water-absorbent resin after 120 minutes (the 120-minute value)is taken as a water-retention degree of swelling of 100%.
  • Table 2 shows a water absorption capacities (measured values) of physiological saline under a load of 4.14 kPa of water-absorbent resins at passing times of 30 minutes, 60 minutes, 120 minutes, and 240 minute after the start of water absorption, and the degrees of swelling under a load(%)which is calculated by the following formula based on the measured value of the water-absorption capacity of physiological saline under the load when a value after 120 minutes (the 120-minute value) for a water-absorbent resin is taken as a degree of swelling under a load of 100%.
  • the water-absorption capacity under a load represents a 120-minute value of the water-absorption capacity of physiological saline under a load of 4.14 kPa as measured by the method described in “(2) water-absorption capacity of physiological saline under a load of 4.14 kPa” in the method of evaluation tests.
  • * 3 The degree of swelling under a load was calculated from a 30-minute value of the water-absorption capacity of physiological saline under a load of 4.14 kPa as measured by the method described in “(2) Water-absorption capacity of physiological saline under a load of 4.14 kPa” in the method of evaluation tests.

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* Cited by examiner, † Cited by third party
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US11401357B2 (en) 2017-10-12 2022-08-02 Sumitomo Seika Chemicals Co., Ltd. Water-absorbent resin and absorbent article
US11466131B2 (en) 2018-11-13 2022-10-11 Lg Chem, Ltd. Superabsorbent polymer and preparation method thereof
US11931720B2 (en) 2017-12-11 2024-03-19 Lg Chem, Ltd. Superabsorbent polymer composition and method for preparing the same

Families Citing this family (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2016028116A (ja) * 2014-07-11 2016-02-25 住友精化株式会社 吸水性樹脂及び吸収性物品
JP6993878B2 (ja) * 2015-03-16 2022-01-14 住友精化株式会社 吸水性樹脂および吸水剤
US11084020B2 (en) * 2017-03-02 2021-08-10 Sumitomo Seika Chemicals Co., Ltd. Water-absorbent resin and absorbent article
EP3604366A4 (en) * 2017-03-29 2021-01-13 Sumitomo Seika Chemicals Co., Ltd. WATER ABSORBENT RESIN
CN107828079A (zh) * 2017-11-03 2018-03-23 宜兴丹森科技有限公司 吸水性树脂及其制造方法
KR102439244B1 (ko) * 2017-11-20 2022-08-31 주식회사 엘지화학 고흡수성 수지 및 이의 제조 방법
JP6681493B1 (ja) * 2018-12-12 2020-04-15 住友精化株式会社 吸水性樹脂粒子の液体漏れ性を評価する方法、及び吸水性樹脂粒子
JPWO2020122202A1 (ja) * 2018-12-12 2021-10-21 住友精化株式会社 吸収性物品
WO2020184389A1 (ja) * 2019-03-08 2020-09-17 住友精化株式会社 吸水性樹脂粒子
EP3936536A1 (en) * 2019-03-08 2022-01-12 Sumitomo Seika Chemicals Co., Ltd. Water absorbing resin particles and method for producing same, absorbent body, and absorbent article
KR20210139288A (ko) * 2019-03-08 2021-11-22 스미토모 세이카 가부시키가이샤 흡수성 수지 입자 및 그 제조 방법
US20220143574A1 (en) * 2019-03-08 2022-05-12 Sumitomo Seika Chemicals Co., Ltd. Water absorbing resin particles and method for producing same, absorbent body, and absorbent article
US20220152268A1 (en) 2019-03-08 2022-05-19 Sumitomo Seika Chemicals Co., Ltd. Water absorbing resin particles and method for producing same, absorbent body. absorbent article, and method for adjusting permeation speed
US20220219140A1 (en) * 2019-04-23 2022-07-14 Sumitomo Seika Chemicals Co., Ltd. Water-absorbent resin particles

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20050059762A1 (en) * 2003-09-12 2005-03-17 Gerd Jonas Superabsorbent polymer with slow absorption times
JP2012236898A (ja) * 2011-05-11 2012-12-06 Sumitomo Seika Chem Co Ltd 吸水性樹脂、及びその製造方法

Family Cites Families (60)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6343912A (ja) * 1986-08-08 1988-02-25 Arakawa Chem Ind Co Ltd 吸水性樹脂の製造法
DE3713601A1 (de) 1987-04-23 1988-11-10 Stockhausen Chem Fab Gmbh Verfahren zur herstellung eines stark wasserabsorbierenden polymerisats
TW201758B (pt) 1988-06-28 1993-03-11 Catalyst co ltd
JP2938920B2 (ja) 1990-01-31 1999-08-25 住友精化株式会社 吸水性樹脂の製造方法
JPH0578420A (ja) 1991-09-18 1993-03-30 Konan Kagaku Kogyo Kk 貯蔵安定性の優れたｗ／ｏ型エマルジヨンポリマーの製造方法
JPH06287233A (ja) 1993-03-31 1994-10-11 Mitsubishi Petrochem Co Ltd 高吸水性ポリマーの製造法
JPH06345819A (ja) 1993-06-08 1994-12-20 Nippon Synthetic Chem Ind Co Ltd:The 高吸水性樹脂の製造法
ES2161730T3 (es) 1993-06-18 2001-12-16 Sanyo Chemical Ind Ltd Composicion absorbente y pañal desechable que la contiene.
US5599335A (en) 1994-03-29 1997-02-04 The Procter & Gamble Company Absorbent members for body fluids having good wet integrity and relatively high concentrations of hydrogel-forming absorbent polymer
JP3597597B2 (ja) 1994-06-08 2004-12-08 株式会社日本触媒 吸水性樹脂及びその製造方法
US5624967A (en) 1994-06-08 1997-04-29 Nippon Shokubai Co., Ltd. Water-absorbing resin and process for producing same
JP2918808B2 (ja) 1994-06-13 1999-07-12 株式会社日本触媒 吸収体および吸収性物品
KR0183511B1 (ko) 1994-06-13 1999-04-15 다나카 쇼소 흡수제와 그 제조방법, 및 흡수제를 포함하는 흡수성 물품
JP2918807B2 (ja) 1994-06-14 1999-07-12 株式会社日本触媒 吸水剤およびその製造方法並びに吸水剤を含む吸収性物品
JPH08120013A (ja) 1994-10-20 1996-05-14 Nippon Synthetic Chem Ind Co Ltd:The 高吸水性樹脂の製造法
TW522024B (en) 1995-09-01 2003-03-01 Nippon Catalytic Chem Ind Absorbing agent composite, absorbent material, and absorbent product containing absorbent material
JP3606966B2 (ja) 1995-11-02 2005-01-05 株式会社日本触媒 吸水性樹脂およびその製造方法
JP3827354B2 (ja) 1996-01-16 2006-09-27 花王株式会社 高吸水性ポリマーの製造方法
TW538055B (en) 1997-04-14 2003-06-21 Nippon Catalytic Chem Ind Pressure-resistant absorbent resin, disposable diaper using the resin and absorbent resin, and method for production thereof
JP4087500B2 (ja) 1997-06-13 2008-05-21 株式会社日本触媒 吸収性物品の製造方法
JPH1129605A (ja) 1997-07-09 1999-02-02 Nippon Junyaku Kk 可溶性アクリル酸系粒状ポリマーの製造方法
JP3810899B2 (ja) 1997-08-29 2006-08-16 株式会社日本触媒 吸水剤の製造方法
JP3326110B2 (ja) * 1998-05-25 2002-09-17 花王株式会社 高吸水性樹脂の製法
EP1072630B1 (en) 1999-07-26 2004-12-01 Nippon Shokubai Co., Ltd. Water-absorbing composition and its use
US6433058B1 (en) 1999-12-07 2002-08-13 Dow Global Technologies Inc. Superabsorbent polymers having a slow rate of absorption
US6579958B2 (en) 1999-12-07 2003-06-17 The Dow Chemical Company Superabsorbent polymers having a slow rate of absorption
KR100409069B1 (ko) 2000-03-06 2003-12-11 주식회사 엘지화학 흡수성 수지의 제조방법
JP2002179712A (ja) 2000-12-15 2002-06-26 Asahi Denka Kogyo Kk 油中水型（ｗ／ｏ型）乳化重合用乳化剤および懸濁重合用分散剤
JP2002212331A (ja) 2001-01-22 2002-07-31 Mitsubishi Chemicals Corp 高吸水性樹脂粒子の製造方法
JP2003088551A (ja) 2001-09-19 2003-03-25 Sumitomo Seika Chem Co Ltd 吸収体およびそれを用いた吸収性物品
EP1592750B1 (en) 2003-02-10 2013-11-13 Nippon Shokubai Co., Ltd. Particulate water absorbent containing water absorbent resin as a main component
JP5064682B2 (ja) 2003-06-13 2012-10-31 住友精化株式会社 吸収体およびそれが用いられた吸収性物品
BRPI0509362A (pt) 2004-03-31 2007-09-11 Nippon Catalytic Chem Ind agente absorvedor de lìquido aquoso e seu processo de produção
JP4776969B2 (ja) 2004-05-07 2011-09-21 株式会社日本触媒 吸水剤およびその製造方法
RU2006140095A (ru) 2004-05-07 2008-06-20 Ниппон Шокубаи Ко. Абсорбирующий агент и способ производства
JP2006068731A (ja) 2004-08-06 2006-03-16 Nippon Shokubai Co Ltd 吸水性樹脂を主成分とする粒子状吸水剤、その製造方法及び吸収性物品
JP4969778B2 (ja) 2004-12-21 2012-07-04 住友精化株式会社 吸水性樹脂粒子の製造方法及びそれを用いた衛生材料
WO2006123561A1 (ja) * 2005-05-16 2006-11-23 Sumitomo Seika Chemicals Co., Ltd. 吸水性樹脂粒子の製造方法、それにより得られる吸水性樹脂粒子、およびそれを用いた吸収体および吸収性物品
TW200720347A (en) 2005-09-30 2007-06-01 Nippon Catalytic Chem Ind Water-absorbent agent composition and method for manufacturing the same
WO2007037453A1 (en) 2005-09-30 2007-04-05 Nippon Shokubai Co., Ltd. Aqueous-liquid-absorbing agent and its production process
JP5191105B2 (ja) 2006-06-27 2013-04-24 住友精化株式会社 吸水性樹脂粒子の製造方法およびそれによって得られる吸水性樹脂粒子
JP5183918B2 (ja) 2006-11-29 2013-04-17 住友精化株式会社 吸水性樹脂の製造方法
US9187579B2 (en) * 2007-02-05 2015-11-17 Nippon Shokubai Co., Ltd. Particle-shaped water absorbing agent and method for producing the same
EP2127741B1 (en) 2007-03-05 2019-05-15 Nippon Shokubai Co., Ltd. Water absorbent and process for producing the same
JP5160810B2 (ja) 2007-05-11 2013-03-13 花王株式会社 重合体粒子の製造方法
JP2009019065A (ja) 2007-07-10 2009-01-29 Kao Corp 重合体粒子の製造方法
US20100331802A1 (en) 2007-08-23 2010-12-30 Sumitomo Seika Chemicals Co., Ltd. Water-absorbent resin suitable for use in hygienic materials
JP2009280668A (ja) 2008-05-21 2009-12-03 San-Dia Polymer Ltd 多孔質吸収性樹脂粒子の製造方法
TR201009212T1 (tr) 2008-06-10 2011-05-23 Kao Corporation Emici eleman ve emici eşya
JP5629529B2 (ja) 2010-08-19 2014-11-19 Ｓｄｐグローバル株式会社 吸収性樹脂粒子及び吸収性物品
KR101989142B1 (ko) 2010-09-30 2019-06-13 가부시기가이샤 닛뽕쇼꾸바이 입자상 흡수제 및 그 제조 방법
US20130330566A1 (en) 2011-03-31 2013-12-12 Sumitomo Seika Chemicals Co., Ltd. Method for producing water-absorbent resin
TWI513713B (zh) * 2011-04-21 2015-12-21 Sumitomo Seika Chemicals 吸水性樹脂之製造方法
TW201247249A (en) 2011-04-21 2012-12-01 Sumitomo Seika Chemicals Water-absorbent resin, absorbent material, and absorbent article
EP2752430B1 (en) * 2011-08-30 2016-07-06 Sumitomo Seika Chemicals CO. LTD. Method for producing water-absorbent resin, and water-absorbent resin obtained by same
CN102504288B (zh) * 2011-10-12 2013-09-25 浙江卫星石化股份有限公司 一种高吸水树脂的制备方法
EP2891520B1 (en) 2012-08-30 2020-02-12 Nippon Shokubai Co., Ltd. Particulate water-absorbing agent and method for manufacturing same
KR102073446B1 (ko) * 2012-09-10 2020-02-05 스미토모 세이카 가부시키가이샤 흡수성 수지, 흡수체 및 흡수성 물품
JP2016503449A (ja) 2012-11-21 2016-02-04 ビーエーエスエフ ソシエタス・ヨーロピアＢａｓｆ Ｓｅ モノマー溶液の液滴を重合することによる吸水性ポリマー粒子の製造方法
JP5893117B2 (ja) * 2014-07-11 2016-03-23 住友精化株式会社 吸水性樹脂及び吸収性物品

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20050059762A1 (en) * 2003-09-12 2005-03-17 Gerd Jonas Superabsorbent polymer with slow absorption times
JP2012236898A (ja) * 2011-05-11 2012-12-06 Sumitomo Seika Chem Co Ltd 吸水性樹脂、及びその製造方法

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
JP 2012-236898, 12-2012, machine translation. *

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US11401357B2 (en) 2017-10-12 2022-08-02 Sumitomo Seika Chemicals Co., Ltd. Water-absorbent resin and absorbent article
US11931720B2 (en) 2017-12-11 2024-03-19 Lg Chem, Ltd. Superabsorbent polymer composition and method for preparing the same
US11466131B2 (en) 2018-11-13 2022-10-11 Lg Chem, Ltd. Superabsorbent polymer and preparation method thereof

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