WO2021049631A1 - Liquid leakage inhibitor used in absorbent containing water absorbent resin particles, and water absorbent resin particles - Google Patents
Liquid leakage inhibitor used in absorbent containing water absorbent resin particles, and water absorbent resin particles Download PDFInfo
- Publication number
- WO2021049631A1 WO2021049631A1 PCT/JP2020/034535 JP2020034535W WO2021049631A1 WO 2021049631 A1 WO2021049631 A1 WO 2021049631A1 JP 2020034535 W JP2020034535 W JP 2020034535W WO 2021049631 A1 WO2021049631 A1 WO 2021049631A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- water
- absorbent resin
- resin particles
- mass
- dry silica
- Prior art date
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
-
- 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
- A61F13/531—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 a homogeneous composition through the thickness of the pad
- A61F13/532—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 a homogeneous composition through the thickness of the pad inhomogeneous in the plane 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
- A61F13/53—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
- A61F13/535—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 inhomogeneous in the plane of the pad, e.g. core absorbent layers being of different sizes
-
- 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
- A61L15/18—Bandages, dressings or absorbent pads for physiological fluids such as urine or blood, e.g. sanitary towels, tampons containing inorganic materials
-
- 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
-
- 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
-
- 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
- B01J20/28—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties
Definitions
- the present invention relates to a liquid leakage inhibitor and water-absorbent resin particles used for an absorber containing water-absorbent resin particles.
- an absorber containing water-absorbent resin particles has been used as an absorbent article for absorbing a liquid containing water as a main component such as urine.
- Patent Document 1 is effective for producing water-absorbent resin particles having a particle size suitable for absorbent articles such as diapers
- Patent Document 2 is effective for containing body fluids such as urine.
- a method of using a hydrogel-absorbing polymer having specific saline flow inducibility, performance under pressure, etc. is disclosed as a specific absorbent member.
- An object of the present invention is to provide a liquid leakage inhibitor used for an absorber containing water-absorbent resin particles.
- dry silica has an effect of suppressing liquid leakage of an absorber containing water-absorbent resin particles. Based on this novel finding, the present invention provides new uses for dry silica.
- One aspect of the present invention relates to a liquid leakage inhibitor used for an absorber containing water-absorbent resin particles, including dry silica.
- 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 liquid leakage inhibitor used for the absorber containing the water-absorbent resin particles according to the embodiment includes dry silica.
- the liquid leakage inhibitor containing dry silica is used as a constituent component of the water-absorbent resin particles containing the polymer particles.
- the dry silica may be placed on the surface of the polymer particles. Liquid leakage can be suppressed by using water-absorbent resin particles containing the liquid leakage inhibitor as the absorber.
- the liquid leakage inhibitor of the present invention includes wet silica, titanium dioxide, aluminum oxide, magnesium oxide, zinc oxide, calcium phosphate, hydrotalcite, bentonite, kaolin, talc, diatomaceous earth, zeolite and other inorganic particles.
- the content of dry silica in the liquid leakage inhibitor may be 70 to 100% by mass, 80 to 100% by mass, or 90 to 100% by mass based on the total mass of the liquid leakage inhibitor.
- the dry silica according to the present invention is silica produced by a dry method, and examples thereof include fumed silica.
- Dry silica generally has an active hydroxyl group and is therefore hydrophilic, but the surface of the silica can be surface-treated with alkylsilane or the like to impart hydrophobicity. From the viewpoint of easily obtaining an excellent initial water absorption rate, the dry silica may have hydrophilicity.
- the dry silica according to the present invention has a nanometer-sized primary particle as a constituent unit, and takes the form of a secondary particle formed by aggregating a plurality of primary particles. Further, in dry silica, a plurality of secondary particles are associated to form a secondary aggregate which is an aggregate of secondary particles.
- the shape of the agglomerates is different between dry silica and synthetic amorphous silica other than dry silica (for example, wet silica produced by a wet method).
- wet silica aggregates are said to have a substantially spherical aggregate structure, whereas dry silica aggregates have a chain-like aggregate structure.
- the specific surface area of the dry silica according to the present invention is, for example, 50 m 2 / g or more, 75 m 2 / g or more, 100 m 2 / g or more, 125 m 2 / g or more, 150 m 2 / g or more, 170 m 2 / g or more, or It may be 200 m 2 / g or more, 1000 m 2 / g or less, 800 m 2 / g or less, 600 m 2 / g or less, 400 m 2 / g or less, or 350 m 2 / g or less.
- the specific surface area of the dry silica may be, for example, 50 to 1000 m 2 / g, 75 to 600 m 2 / g, or 100 to 400 m 2 / g.
- the specific surface area of dry silica can be measured by the BET specific surface area (N 2) method.
- the bulk density of the dry silica according to the present invention may be, for example, 10 to 200 g / L.
- the bulk density of the dry silica may be 10 g / L or more, 20 g / L or more, 30 g / L or more, or 40 g / L or more, and 200 g / L or less, 180 g / L or more.
- it may be 150 g / L or less, 130 g / L or less, 100 g / L or less, 90 g / L or less, or 80 g / L or less.
- the bulk density of silica can be measured by using a pigment test method (JIS-K5101-12-1) or a powder property evaluation device described later.
- the average particle size (primary average particle size) of the primary particles of the dry silica according to the present invention is 5 nm or more, 7 nm or more, 10 nm or more, or 12 nm or more from the viewpoint of handleability and adhesion to the surface of the water-absorbent resin particles. It may be 500 nm or less, 100 nm or less, 50 nm or less, 30 nm or less, or 20 nm or less. More specifically, the primary average particle size of the dry silica may be 5 nm or more and 500 nm or less, and may be 7 nm or more and 50 nm or less. The average primary particle size of silica can be measured by observation with a transmission electron microscope.
- the average particle size of the secondary agglomerated particles of the dry silica according to the present invention may be 1.0 ⁇ m or more, 10 ⁇ m or more, or 20 ⁇ m or more, and 100 ⁇ m or less, 70 ⁇ m, from the viewpoint of easy handling and excellent water absorption characteristics. It may be less than or equal to 50 ⁇ m or less. From the same viewpoint, more specifically, the average particle size of the secondary agglomerated particles of the dry silica may be 1.0 ⁇ m or more and 100 ⁇ m or less, and 10 ⁇ m or more and 70 ⁇ m or less.
- the average particle size of the secondary agglomerated particles of silica can be measured by a dynamic light scattering method, a laser diffraction / scattering method, or a Coulter counter method.
- the water content of the dry silica according to the present invention may be, for example, 10% by mass or less, 5.0% by mass or less, 3.0% by mass or less, or 2.0% by mass or less.
- the lower limit of the water content of the dry silica may be, for example, 0.01% by mass or more, 0.05% by mass or more, or 0.1% by mass or more.
- the dry silica may be fumed silica having a water content of 5% by mass or less.
- the water content of the dry silica can be measured by the general test method ISO787-2 for pigments and extender pigments.
- the water content of the dry silica in the present specification is a water content based on the total mass of the dry silica and the water in the dry silica.
- dry silica hydrophilic dry silica
- dry silica hydrophilic dry silica
- examples of dry silica include "Aerosil 200", “Aerosil 300", “Aerosil 380” manufactured by Nippon Aerosil Co., Ltd., and "CAB-O-SIL M-5" manufactured by Cabot Japan Co., Ltd.
- CAB-O-SIL H-300 “CAB-O-SIL M-5", “CAB-O-SIL M3KD", OCI Company, Ltd.
- KONASIL K-200 "KONASIL K-150
- the one sold as "Leolosil QS-102" manufactured by Tokuyama Corporation can be used. These may be used alone or in combination of two or more.
- the water-absorbent resin particles according to the present embodiment may contain polymer particles and the above-mentioned liquid leakage inhibitor arranged on the surface of the polymer particles.
- the liquid leakage inhibitor can be arranged on the surface of the polymer particles.
- the content of the liquid leakage inhibitor is 0.2 parts by mass or more, 0.35 parts by mass or more, 0.5 parts by mass or more, 1.0 parts by mass or more, or more than 100 parts by mass of the polymer particles. It may be 1.5 parts by mass or more, 5.0 parts by mass or less, 3.5 parts by mass or less, or 2.5 parts by mass or less.
- the content of the dry silica may be within the range described in the content of the liquid leakage inhibitor. When the content of the liquid leakage inhibitor and / or the content of the dry silica is within the above range, the liquid leakage suppression effect becomes even more excellent.
- Water absorption rate index I (10-second value of non-pressurized DW) x 6 [mL / g]
- Water absorption rate index II (3 minutes value of non-pressurized DW) / 3 [mL / g]
- ⁇ (I + II) / 2
- the static suction index ⁇ calculated in 1 may be 5.0 mL / g or more.
- the non-pressurized DW is the amount of the water-absorbent resin particles that have absorbed the physiological saline solution within a predetermined time after the contact with the physiological saline solution (saline solution having a concentration of 0.9% by mass) under no pressurization. It is the water absorption rate represented by.
- the non-pressurized DW is represented by the absorption amount (mL) per 1 g of the water-absorbent resin particles before the absorption of the physiological saline.
- the 10-second value and the 3-minute value of the non-pressurized DW mean the amount of absorption 10 seconds and 3 minutes after the water-absorbent resin particles come into contact with the physiological saline solution, respectively.
- the water absorption rate indexes I and II correspond to the values obtained by converting the 10-second value and the 3-minute value of the non-pressurized DW into the water absorption rate per minute.
- the static suction index ⁇ corresponds to the average value of the water absorption rate indexes I and II, and a large static suction index ⁇ means that a relatively large water absorption rate is maintained for 10 seconds to 3 minutes. To do. According to the findings of the present inventor, when the static suction index ⁇ of the water-absorbent resin particles is 5.0 mL / g or more, liquid leakage is suppressed more effectively.
- Static suction index ⁇ is 6.0 mL / g or more, 7.0 mL / g or more, 9.0 mL / g or more, 10 mL / g or more, 11 mL / g or more, 12 mL / g or more, 13 mL / g or more, 14 mL / g It may be more than or equal to 15 mL / g or more.
- the upper limit of the static suction index ⁇ is usually 25 mL / g or less, or 20 mL / g or less.
- the water absorption rate index I may be 2 mL / g or more, 4 mL / g or more, 6 mL / g or more, or 8 mL / g or more, and may be 30 mL / g or less, or 25 mL / g or less.
- the water absorption rate index II may be 8 mL / g or more, 12 mL / g or more, 16 mL / g or more, 30 mL / g or less, or 25 mL / g or less.
- the static suction index ⁇ tends to be 5.0 mL / g.
- the liquid leakage inhibitor is arranged on the polymer particles, the amount thereof is adjusted, and the surface area of the polymer particles is increased.
- the crosslink density in the surface layer of the polymer particles can be adjusted, or a combination thereof can be obtained.
- the water-retaining amount of the physiological saline of the water-absorbent resin particles according to the present embodiment is, for example, 20 g / g or more, 25 g / g or more, 30 g / g or more, 32 g / g or more, 34 g / g or more, 36 g / g or more. It may be 38 g / g or more, 39 g / g or more, 60 g / g or less, 55 g / g or less, 50 g / g or less, 45 g / g or less, or 42 g / g or less.
- the water-retaining amount of the physiological saline of the water-absorbent resin particles according to the present embodiment may be 20 to 60 g / g, 25 to 60 g / g, 30 to 55 g / g, or 32 to 55 g / g.
- the amount of physiological saline retained is measured by the method described in Examples described later.
- Examples of the shape of the water-absorbent resin particles according to the present embodiment include a substantially spherical shape, a crushed shape, a granular shape, and a shape formed by aggregating primary particles having these shapes.
- the polymer particles may be water-absorbent 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 proportion of the polymer containing the ethylenically unsaturated monomer as a monomer unit in the polymer particles is 50 to 100% by mass, 60 to 100% by mass, and 70 to 100% by mass based on the mass of the polymer particles. , Or 80 to 100% by mass.
- the polymer particles may be particles containing a (meth) acrylic acid-based polymer containing at least one of (meth) acrylic acid or (meth) acrylate as a monomer unit.
- the total ratio of the monomer units derived from (meth) acrylic acid or (meth) acrylate in the (meth) acrylic acid-based polymer may be 90 to 100% by mass based on the mass of the polymer. Good.
- the surface cross-linking agent may be, for example, a compound having two or more functional groups (reactive functional groups) having reactivity with a functional group derived from an ethylenically unsaturated monomer.
- the surface cross-linking agent include alkylene carbonate compounds such as ethylene carbonate and propylene carbonate; ethylene glycol, propylene glycol, 1,4-butanediol, trimethylolpropane, glycerin, polyoxyethylene glycol, polyoxypropylene glycol, and polyglycerin.
- Polysaccharides such as (poly) ethylene glycol diglycidyl ether, (poly) glycerin diglycidyl ether, (poly) glycerin triglycidyl ether, (poly) propylene glycol polyglycidyl ether, (poly) glycerol polyglycidyl ether and the like.
- Haloepoxy compounds such as epichlorohydrin, epibromhydrin, ⁇ -methylepicrolhydrin; compounds having two or more reactive functional groups such as isocyanate compounds such as 2,4-tolylene diisocyanate and hexamethylene diisocyanate; 3-methyl- 3-Oxetane methanol, 3-ethyl-3-oxetane methanol, 3-butyl-3-oxetane methanol, 3-methyl-3-oxetane ethanol, 3-ethyl-3-oxetane ethanol, 3-butyl-3-oxetane ethanol, etc.
- the surface cross-linking agent may contain a polyglycidyl compound.
- the ratio of the polyglycidyl compound in the surface cross-linking agent is 50 to 100% by mass, 60 to 100% by mass, 70 to 100% by mass, 80 to 100% by mass, or 90 to 100% by mass based on the total mass of the surface cross-linking agent. It may be.
- the polymer may be internally crosslinked by self-crosslinking, cross-linking by reaction with an internal cross-linking agent, or both. From the viewpoint of ease of control of water absorption characteristics, at least a reaction by an internal cross-linking agent may be included.
- the internal cross-linking agent is, for example, a compound having two or more polymerizable unsaturated groups, a compound having two or more reactive functional groups having reactivity with a functional group of an ethylenically unsaturated monomer, or a compound thereof. It can contain one or more compounds, including combinations.
- polyethylene glycol As an example of a compound having two or more polymerizable unsaturated groups, (poly) ethylene glycol (in this specification, for example, “polyethylene glycol” and “ethylene glycol” are collectively referred to as “(poly) ethylene glycol”.
- Di or tri (meth) acrylic acid esters of polyols such as (poly) propylene glycol, trimethylolpropane, glycerin polyoxyethylene glycol, polyoxypropylene glycol, and (poly) glycerin; Unsaturated polyesters obtained by reacting with unsaturated acids such as maleic acid and fumaric acid; bisacrylamides such as N, N'-methylenebis (meth) acrylamide; by reacting polyepoxide with (meth) acrylic acid.
- polyols such as (poly) propylene glycol, trimethylolpropane, glycerin polyoxyethylene glycol, polyoxypropylene glycol, and (poly) glycerin
- Unsaturated polyesters obtained by reacting with unsaturated acids such as maleic acid and fumaric acid
- bisacrylamides such as N, N'-methylenebis (meth) acrylamide
- di (meth) acrylic acid esters obtained di (meth) acrylic acid carbamil esters obtained by reacting polyisocyanates such as tolylene diisocyanate and hexamethylene diisocyanate with hydroxyethyl (meth) acrylic acid; Alylated starch; allylated cellulose; diallyl phthalate; N, N', N''-triallyl isocyanurate; divinylbenzene.
- Examples of compounds having two or more reactive functional groups include glycidyl group-containing compounds such as (poly) ethylene glycol diglycidyl ether, (poly) propylene glycol diglycidyl ether, and (poly) glycerin diglycidyl ether; (poly). ) Ethylene glycol, (poly) propylene glycol, (poly) glycerin, pentaerythritol, ethylenediamine, polyethyleneimine, glycidyl (meth) acrylate.
- glycidyl group-containing compounds such as (poly) ethylene glycol diglycidyl ether, (poly) propylene glycol diglycidyl ether, and (poly) glycerin diglycidyl ether; (poly). ) Ethylene glycol, (poly) propylene glycol, (poly) glycerin, pentaerythritol, ethylenedi
- the polymer particles may be crosslinked after polymerization. For example, by adding a cross-linking agent to the polymer and heating it, cross-linking can be performed after the polymerization. By performing cross-linking after polymerization, the degree of cross-linking of the polymer can be increased, whereby the water-absorbing characteristics of the water-absorbent resin particles can be further improved.
- 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; 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 ethylene carbonate and propylene carbonate; Examples thereof include hydroxyalkylamide compounds such as bis [N, N-di ( ⁇ -hydroxyethyl)] adip
- 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 post-polymerization cross-linking agent may contain a polyglycidyl compound.
- the ratio of the polyglycidyl compound in the post-polymerization cross-linking agent is 50 to 100% by mass, 60 to 100% by mass, 70 to 100% by mass, 80 to 100% by mass, or 90 to 100% based on the total mass of the post-polymerization cross-linking agent. It may be% by mass.
- the time for adding the cross-linking after the polymerization may be after the polymerization of the ethylenically unsaturated monomer used for the polymerization, and in the case of the multi-stage polymerization, it may be added after the multi-stage polymerization.
- a cross-linking agent for post-polymerization cross-linking May be added in the region of [water content immediately after polymerization ⁇ 3%] from the viewpoint of water content (water content based on the mass of the water-containing gel-like polymer).
- the medium particle size of the polymer particles may be 130 to 800 ⁇ m, 200 to 850 ⁇ m, 250 to 700 ⁇ m, 300 to 600 ⁇ m, or 300 to 450 ⁇ m.
- the polymer 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. ..
- the polymer particles may contain a certain amount of water in addition to the polymer of the ethylenically unsaturated monomer, and may further contain various additional components therein.
- additional ingredients include gel stabilizers, metal chelating agents, antibacterial agents and the like.
- the water-absorbent resin particles according to the above-exemplified embodiments can be produced, for example, by a method including a step of arranging the liquid leakage inhibitor on the surface of the polymer particles.
- the polymer particles can be obtained, for example, by a method including a step of polymerizing a monomer containing an ethylenically unsaturated monomer.
- the polymerization method of the monomer 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.
- polymer particles internally cross-linked by the cross-linking agent may be obtained.
- Polymer particles containing inorganic particles may be obtained by polymerizing an ethylenically unsaturated monomer in the presence of inorganic particles such as silica.
- a part or all of the ethylene-based unsaturated monomer may form a salt such as an alkali metal salt.
- the ethylenically unsaturated monomer is polymerized in a monomer aqueous solution containing an ethylenically unsaturated monomer and water to form a hydrogel polymer containing the polymer.
- the polymer particles can be obtained by a method including the above and drying of the hydrogel polymer.
- a lumpy hydrogel polymer is formed, it may be coarsely crushed and the crude product of the hydrogel polymer may be dried.
- the hydrogel polymer or a crude product thereof may be dried and then pulverized, or the particles obtained by pulverization may be classified.
- the polymer particles used for surface cross-linking may be a dried coarsely crushed product or particles obtained by further pulverizing the coarsely crushed product.
- the polymer particles obtained by pulverizing the coarsely crushed product may be classified, the particle size of the polymer particles may be adjusted as necessary, and then subjected to surface cross-linking.
- the concentration of the ethylenically unsaturated monomer in the aqueous monomer solution may be 20% by mass or more and less than the saturated concentration, 25 to 70% by mass, or 30 to 50% by mass based on the mass of the aqueous monomer solution. Good.
- the monomer aqueous solution may further contain a polymerization initiator.
- the polymerization initiator may be a photopolymerization initiator or a thermal radical polymerization initiator, or may be a water-soluble thermal radical polymerization initiator.
- the thermally radically polymerizable compound may be an azo compound, a peroxide, or a combination thereof.
- the amount of the polymerization initiator may be 0.00005 to 0.01 mol per 1 mol of the ethylenically unsaturated monomer.
- the monomer aqueous solution may further contain the above-mentioned internal cross-linking agent.
- the amount of the internal cross-linking agent is 0 mmol or more, 0.001 mmol or more, 0.01 mmol or more, 0.015 mmol or more, or 0.020 mmol or more with respect to 1 mol of the ethylenically unsaturated monomer. It may be 2 mmol or less, 1 mmol or less, 0.5 mmol or less, or 0.1 mmol or less.
- the aqueous monomer solution may further contain other additives such as a chain transfer agent and a thickener.
- the polymerization temperature varies depending on the polymerization initiator used, but may be, for example, 0 to 130 ° C. or 10 to 110 ° C.
- the polymerization time may be 1 to 200 minutes or 5 to 100 minutes.
- the water content of the hydrogel polymer formed by polymerization (water content based on the mass of the hydrogel polymer) is 30 to 80% by mass, 40 to 75% by mass, or 50 to 70% by mass. May be.
- the coarsely crushed product obtained by the coarse crushing may be in the form of particles or may have an elongated shape such that particles are connected.
- the minimum width of the pyroclastic material may be, for example, about 0.1 to 15 mm or 1.0 to 10 mm.
- the maximum width of the pyroclastic material may be about 0.1 to 200 mm or 1.0 to 150 mm.
- devices for crushing include kneaders (eg, pressurized kneaders, double-armed kneaders, etc.), meat choppers, cutter mills, and pharmacomills. If necessary, the lumpy hydrogel polymer may be cut before coarse crushing.
- the hydrogel polymer or its crude product is dried mainly to remove water.
- the drying method may be a general method such as natural drying, heat drying, and vacuum drying.
- the crushing method is not particularly limited, and for example, a roller mill (roll mill), a stamp mill, a jet mill, a high-speed rotary crusher (hammer mill, pin mill, rotor beater mill, etc.), or a container-driven mill (rotary mill, vibration mill, etc.). , Planet mill, etc.) can be applied.
- the classification method is also not particularly limited, and for example, a method using a vibrating sieve, a rotary shifter, a cylindrical stirring sieve, a blower shifter, or a low-tap type shaker can be applied.
- a suspension containing an activator an ethylenically unsaturated monomer is polymerized to form a particulate hydrogel polymer containing the polymer, and hydrocarbon dispersion from the suspension.
- Polymer particles can be obtained by methods involving removing the medium and water.
- 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 amount of the hydrocarbon dispersion medium may be 30 to 1000 parts by mass, 40 to 500 parts by mass, or 50 to 300 parts by mass with respect to 100 parts by mass of the aqueous monomer solution containing the monomer.
- thermal radical polymerization initiators include persulfates, peroxides, and azo compounds.
- the amount of the radical polymerization initiator may be 0.00005 to 0.01 mol per 1 mol of the ethylenically unsaturated monomer.
- the suspension for reverse phase suspension polymerization may further contain the above-mentioned internal cross-linking agent.
- the internal cross-linking agent is usually added to a monomer aqueous solution containing an ethylene-based unsaturated monomer.
- the amount of the internal cross-linking agent is 0 mmol or more, 0.001 mmol or more, 0.01 mmol or more, 0.015 mmol or more, or 0.020 mmol or more with respect to 1 mol of the ethylenically unsaturated monomer. It may be 2 mmol or less, 1 mmol or less, 0.5 mmol or less, or 0.1 mmol or less.
- Suspensions for reverse phase suspension polymerization usually further contain a surfactant.
- the surfactant may be a nonionic surfactant, an anionic surfactant or the like.
- nonionic surfactants include sorbitan fatty acid ester and (poly) glycerin fatty acid ester (“(poly)” means both with and without the prefix “poly”. The same applies 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, polyoxy.
- Examples thereof include ethylene castor 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 taur phosphates, polyoxyethylene alkylphenyl ether sulfates, polyoxyethylene alkyl ether sulfonates, and phosphorus in polyoxyethylene alkyl ethers.
- Examples thereof include acid esters and phosphoric acid esters of polyoxyethylene alkyl allyl ethers.
- the surfactant 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 aqueous monomer solution.
- the suspension for reverse phase suspension polymerization may further contain a polymer-based dispersant.
- polymer dispersants include maleic anhydride-modified polyethylene, maleic anhydride-modified polypropylene, maleic anhydride-modified ethylene / propylene copolymer, maleic anhydride-modified EPDM (ethylene / propylene / diene / terpolymer), and anhydrous.
- maleic acid-modified polybutadiene maleic anhydride / ethylene copolymer, maleic anhydride / propylene copolymer, maleic anhydride / ethylene / propylene copolymer, maleic anhydride / butadiene copolymer, polyethylene, polypropylene, ethylene / propylene Examples thereof include copolymers, oxidized polyethylene, oxidized polypropylene, oxidized ethylene / propylene copolymers, ethylene / acrylic acid copolymers, ethyl cellulose, ethyl hydroxyethyl cellulose and the like.
- the polymer-based dispersant may be used alone or in combination of two or more.
- 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 aqueous monomer solution.
- the suspension for reverse phase suspension polymerization may contain other components such as a chain transfer agent and a thickener, if necessary.
- the temperature of the polymerization reaction varies depending on the radical polymerization initiator used, but may be, for example, 20 to 150 ° C. or 40 to 120 ° C.
- the reaction time is usually 0.5-4 hours.
- the reverse phase suspension polymerization may be carried out in a plurality of times.
- the polymer particles can be obtained by removing the hydrocarbon dispersion medium and water from the suspension containing the hydrogel polymer and the hydrocarbon dispersion medium.
- azeotropic distillation, decantation, filtration, vacuum drying, or a combination thereof can remove the hydrocarbon dispersion medium and water. Water, hydrocarbon dispersion medium, or both may remain in the polymer particles to some extent.
- the method for producing water-absorbent resin particles further includes a step of surface-crosslinking the polymer particles by heating a reaction mixture containing the polymer particles and an aqueous solution of a surface-crosslinking agent containing water and a surface-crosslinking agent. Good.
- the surface cross-linking agent aqueous solution contains water and a surface cross-linking agent dissolved in water.
- the aqueous surface cross-linking agent solution may further contain a hydrophilic organic solvent.
- the organic solvent may be, for example, an alcohol such as 2-propanol, ethanol or methanol.
- the ratio of water to the total amount of water and the organic solvent is 100% by mass or less, and may be 50% by mass or more, 60% by mass or more, 70% by mass or more, 80% by mass or more, or 90% by mass or more. ..
- the polymer particles can be surface-crosslinked by mixing the polymer particles and the aqueous surface cross-linking agent solution and heating the reaction mixture formed with stirring, if necessary.
- the heating temperature for surface cross-linking may be appropriately adjusted so that the surface cross-linking proceeds, for example, 70 to 300 ° C., 100 to 270 ° C., 120 to 250 ° C., 150 to 220 ° C., or 170 to 200 ° C. You may.
- the reaction time for surface cross-linking may be, for example, 1 to 200 minutes, 10 to 100 minutes, 20 to 80 minutes, 30 to 70 minutes, 40 to 60 minutes, or 5 to 100 minutes.
- the surface cross-linking step may be carried out twice or more.
- Water and hydrocarbon dispersion medium are removed from the polymer particles after surface cross-linking, if necessary.
- the polymer particles after surface cross-linking may be further treated by drying, grinding, classification or a combination thereof.
- the method for producing the water-absorbent resin particles may include a step of arranging the liquid leakage inhibitor after surface cross-linking.
- the absorber according to one embodiment contains the water-absorbent resin particles according to this embodiment.
- the absorber according to the present embodiment can contain a fibrous substance, for example, a mixture containing water-absorbent resin particles and the fibrous substance.
- the structure of the absorber may be, for example, a structure in which the water-absorbent resin particles and the fibrous material are uniformly mixed, and the water-absorbent resin particles are sandwiched between the fibrous material formed in a sheet or layer. It may be a configuration or another configuration.
- the fibrous material examples include finely pulverized wood pulp; cotton; cotton linter; rayon; cellulosic fibers such as cellulose acetate; synthetic fibers such as polyamide, polyester and polyolefin; and a mixture of these fibers.
- the fibrous material may be used alone or in combination of two or more.
- hydrophilic fibers can be used as the fibrous material.
- the mass ratio of the water-absorbent resin particles in the absorber is 40% by mass or more, 45% by mass or more, 50% by mass or more, 55% by mass or more, and 60% by mass or more with respect to the total of the water-absorbent resin particles and the fibrous material. , 65% by mass or more, or 70% by mass.
- the mass ratio of the water-absorbent resin particles in the absorber is 100% by mass or less, 95% by mass or less, 90% by mass or less, 85% by mass or less, or 80 with respect to the total of the water-absorbent resin particles and the fibrous material. It may be% by mass.
- the mass ratio of the water-absorbent resin particles in the absorber may be 40 to 100% by mass, 50 to 95% by mass, or 60 to 90% by mass with respect to the total of the water-absorbent resin particles and the fibrous material.
- the fibers may be adhered to each other by adding an adhesive binder to the fibrous material.
- the adhesive binder include heat-sealing synthetic fibers, hot melt adhesives, and adhesive emulsions.
- the adhesive binder may be used alone or in combination of two or more.
- the heat-bondable synthetic fiber examples include a total fusion type binder such as polyethylene, polypropylene, and an ethylene-propylene copolymer; a side-by-side of polypropylene and polyethylene, and a non-total fusion type binder having a core-sheath structure.
- a total fusion type binder such as polyethylene, polypropylene, and an ethylene-propylene copolymer
- a side-by-side of polypropylene and polyethylene examples of the heat-bondable synthetic fiber.
- a non-total fusion type binder only the polyethylene portion can be heat-sealed.
- hot melt adhesive examples include ethylene-vinyl acetate copolymer, styrene-isoprene-styrene block copolymer, styrene-butadiene-styrene block copolymer, styrene-ethylene-butylene-styrene block copolymer, and styrene-ethylene-propylene-styrene block copolymer.
- a mixture of a base polymer such as amorphous polypropylene and a tackifier, a plasticizer, an antioxidant and the like.
- Examples of the adhesive emulsion include polymers of at least one monomer selected from the group consisting of methyl methacrylate, styrene, acrylonitrile, 2-ethylhexyl acrylate, butyl acrylate, butadiene, ethylene, and vinyl acetate.
- the absorber according to the present embodiment may contain a deodorant, an antibacterial agent, a fragrance and the like.
- the shape of the absorber according to the present embodiment is not particularly limited, and may be, for example, a sheet shape.
- the thickness of the absorber (for example, the thickness of the sheet-shaped absorber) may be, for example, 0.1 to 20 mm and 0.3 to 15 mm.
- the absorbent article according to the present embodiment includes an absorber according to the present embodiment.
- the absorbent article according to the present embodiment is a core wrap that retains the shape of the absorber; a liquid permeable sheet that is arranged on the outermost side of the side where the liquid to be absorbed enters; Examples thereof include a liquid permeable sheet arranged on the outermost side on the opposite side.
- absorbent articles include diapers (for example, paper diapers), toilet training pants, incontinence pads, sanitary materials (sanitary napkins, tampons, etc.), sweat pads, pet sheets, toilet members, animal excrement treatment materials, and the like. ..
- FIG. 1 is a cross-sectional view showing an example of an absorbent article.
- the absorbent article 100 shown in FIG. 1 includes an absorbent body 10, core wraps 20a and 20b, a liquid permeable sheet 30, and a liquid permeable sheet 40.
- the liquid permeable sheet 40, the core wrap 20b, the absorbent body 10, the core wrap 20a, and the liquid permeable sheet 30 are laminated in this order.
- the absorber 10 has a water-absorbent resin particle 10a according to the present embodiment and a fiber layer 10b containing a fibrous material.
- the water-absorbent resin particles 10a are dispersed in the fiber layer 10b.
- the core wrap 20a is arranged on one side of the absorber 10 (upper side of the absorber 10 in FIG. 1) in contact with the absorber 10.
- the core wrap 20b is arranged on the other side of the absorber 10 (lower side of the absorber 10 in FIG. 1) in contact with the absorber 10.
- the absorber 10 is arranged between the core wrap 20a and the core wrap 20b.
- Examples of the core wraps 20a and 20b include tissues, non-woven fabrics and the like.
- the core wrap 20a and the core wrap 20b have, for example, a main surface having the same size as the absorber 10.
- the liquid permeable sheet 30 is arranged on the outermost side on the side where the liquid to be absorbed enters.
- the liquid permeable sheet 30 is arranged on the core wrap 20a in contact with the core wrap 20a.
- Examples of the liquid permeable sheet 30 include non-woven fabrics made of synthetic resins such as polyethylene, polypropylene, polyester and polyamide, and porous sheets.
- the liquid permeable sheet 40 is arranged on the outermost side of the absorbent article 100 on the opposite side of the liquid permeable sheet 30.
- the liquid impermeable sheet 40 is arranged under the core wrap 20b in contact with the core wrap 20b.
- liquid impermeable sheet 40 examples include a sheet made of a synthetic resin such as polyethylene, polypropylene, and polyvinyl chloride, and a sheet made of a composite material of these synthetic resins and a non-woven fabric.
- the liquid permeable sheet 30 and the liquid permeable sheet 40 have, for example, a main surface wider than the main surface of the absorber 10, and the outer edges of the liquid permeable sheet 30 and the liquid permeable sheet 40 are It extends around the absorber 10 and the core wraps 20a, 20b.
- the magnitude relationship between the absorbent body 10, the core wraps 20a and 20b, the liquid permeable sheet 30, and the liquid permeable sheet 40 is not particularly limited, and is appropriately adjusted according to the use of the absorbent article and the like. Further, the method of retaining the shape of the absorber 10 using the core wraps 20a and 20b is not particularly limited, and as shown in FIG. 1, the absorber may be wrapped by a plurality of core wraps, and the absorber is wrapped by one core wrap. But it may be.
- the liquid absorbing method according to the present embodiment includes a step of bringing the liquid to be absorbed into contact with the absorber or the absorbent article according to the present embodiment.
- the method for suppressing liquid leakage of an absorber containing water-absorbent resin particles according to the present embodiment includes a step of incorporating dry silica as a liquid leakage inhibitor into the water-absorbent resin particles.
- the step of containing the dry silica may be a step of containing the dry silica by mixing the polymer particles described above with the dry silica.
- the use or application of dry silica for suppressing liquid leakage of an absorber containing water-absorbent resin particles is provided.
- the use or application of dry silica for producing a liquid leakage inhibitor used for an absorber containing water-absorbent resin particles is provided.
- ⁇ Preparation of silica as a liquid leakage inhibitor> (Dry silica A)
- the specific surface area is 200 ⁇ 5 m 2 / g
- the bulk density is 33 g / L
- the water content is 1.0% or less
- the primary average particle size is 7 to 20 nm
- the average particle size of the secondary aggregate is 30 to 50 ⁇ m.
- Dry silica (Cabot Japan Co., Ltd., product name: M-5) was prepared. This was designated as dry silica A.
- Dry silica B The specific surface area is 300 ⁇ 5 m 2 / g, the bulk density is 40 g / L, the water content is 1.0% or less, the primary average particle size is 7 to 20 nm, and the average particle size of the secondary aggregate is 30 to 50 ⁇ m.
- Dry silica (Cabot Japan Co., Ltd., product name: H300) was prepared. This was designated as dry silica B.
- Dry silica C The specific surface area is 200 ⁇ 5 m 2 / g, the bulk density is 54 g / L, the water content is 1.0% or less, the primary average particle size is 7 to 20 nm, and the average particle size of the secondary aggregate is 30 to 50 ⁇ m.
- Dry silica (Cabot Japan Co., Ltd., product name: M3KD) was prepared. This was designated as dry silica C.
- Dry silica E A dry silica (OCI Company, Ltd., product name: KONASIL K-200) having a specific surface area of 216 m 2 / g, a bulk density of 41 g / L, a water content of 0.1%, a primary average particle size of 12 nm, and a dry silica (manufactured by OCI Company, Ltd.) was prepared. .. This was designated as dry silica E.
- Dry silica F A dry silica (OCI Company, Ltd., product name: KONASIL K-150) having a specific surface area of 155 m 2 / g, a bulk density of 47 g / L, a water content of 0.1%, a primary average particle size of 14 nm, and a dry silica (manufactured by OCI Company, Ltd.) was prepared. .. This was designated as dry silica F.
- Dry silica G A dry silica (manufactured by Tokuyama Corporation, product name: Leoloseal QS-102) having a specific surface area of 200 m 2 / g, a bulk density of 35 g / L, a water content of 1.5% or less, and a primary average particle diameter of 12 nm was prepared. .. This was designated as dry silica G.
- Wet silica (specific surface area 190 m 2 / g, bulk density 100 g / L, moisture content 6.1%, primary average particle size 10-30 nm, average particle size of secondary aggregates 9.8 ⁇ m) OSC (Oriental Silkas Corporation), product name: Toxile NPS) was prepared.
- the specific surface area is a value measured by the BET specific surface area (N 2 ) method
- the water content is a value measured by the general test method ISO787-2 for pigments and extender pigments
- the primary average particles are transmitted electrons. It is a value measured by observation with a microscope
- the average particle size of the secondary aggregate is a value measured by a laser diffraction / scattering method.
- the bulk density of silica as a liquid leakage inhibitor was measured by the following procedure using a powder property evaluation device (manufactured by Hosokawa Micron Co., Ltd., model number: PT-X). The bulk density was measured at room temperature (25 ° C ⁇ 2 ° C).
- the mass W 0 of an empty container (cup XS-18, inner diameter 5.0 cm, height 5.0 cm, volume 100 cm 3 ) was measured.
- about 120 mL of silica was put into the container using the scoop XS-12 attached to the device.
- the blade XS-13 was used to scrape off the silica protruding from the upper part of the container.
- the mass was measured W 1 of the vessel containing the silica.
- the bulk density was calculated from the following formula. The bulk density was measured three times in total, and the average value was obtained as the bulk density of silica.
- Bulk density of silica [g / L] (W 1 [g] -W 0 [g]) / 100 [cm 3 ] x 1000
- hydroxylethyl cellulose Suditomo Seika Co., Ltd., HECAW-15F
- 2,2'-azobis (2-amidinopropane) dihydrochloride as a water-soluble radical polymerization initiator were added to an aqueous acrylic acid solution.
- the first step is to dissolve 0.092 g (0.339 mmol), 0.018 g (0.067 mmol) of potassium persulfate, and 0.010 g (0.057 mmol) of ethylene glycol diglycidyl ether as an internal cross-linking agent.
- a monomer aqueous solution of the above was prepared.
- the first-stage monomer aqueous solution was added to the above-mentioned reaction solution in the separable flask, and the reaction solution was stirred for 10 minutes.
- a surfactant solution containing 6.62 g of n-heptane and 0.736 g of sucrose stearic acid ester (HLB: 3, Mitsubishi Chemical Foods Co., Ltd., Ryoto Sugar Ester S-370) was added to the reaction solution, and the mixture was stirred.
- the inside of the system was sufficiently replaced with nitrogen while stirring the reaction solution at a blade rotation speed of 550 rpm.
- the polymerization reaction was allowed to proceed over 60 minutes while heating the separable flask in a water bath at 70 ° C. By this polymerization reaction, a first-stage polymerization slurry liquid containing a hydrogel-like polymer was obtained.
- Second-stage polymerization reaction 128.8 g (1.44 mol) of an acrylic acid aqueous solution having a concentration of 80.5% by mass was placed in a beaker having an internal volume of 500 mL. While cooling the beaker from the outside, 159.0 g of a sodium hydroxide aqueous solution having a concentration of 27% by mass was added dropwise to the acrylic acid aqueous solution, thereby neutralizing 75 mol% of acrylic acid. Next, 0.129 g (0.476 mmol) of 2,2'-azobis (2-amidinopropane) dihydrochloride and 0.026 g (0.096 mmol) of potassium persulfate were dissolved in an aqueous acrylic acid solution. A second-stage monomer aqueous solution was prepared.
- the first-stage polymerized slurry liquid in the separable flask was cooled to 25 ° C. while stirring at a stirring blade rotation speed of 1000 rpm.
- the whole amount of the aqueous monomer solution of the second stage was added thereto, and then the inside of the system was replaced with nitrogen over 30 minutes.
- the polymerization reaction was allowed to proceed over 60 minutes while heating the separable flask in a water bath at 70 ° C.
- a cross-linking agent for post-polymerization cross-linking 0.580 g (0.067 mmol) of a 2% by mass ethylene glycol diglycidyl ether aqueous solution was added to obtain a hydrogel polymer.
- 0.265 g of a diethylenetriamine-5 sodium acetate aqueous solution having a concentration of 45% by mass was added to the reaction solution containing the hydrogel polymer under stirring. Then, the flask was immersed in an oil bath set at 125 ° C., and 239.0 g of water was extracted from the system by azeotropic distillation of n-heptane and water. Then, 4.42 g (0.507 mmol) of an ethylene glycol diglycidyl ether aqueous solution having a concentration of 2% by mass was added to the reaction solution as a surface cross-linking agent, and the cross-linking reaction with the surface cross-linking agent was allowed to proceed at 83 ° C. for 2 hours. It was.
- reaction solution After the surface cross-linking reaction, n-heptane and water were distilled off by heating at 125 ° C. to obtain a reaction product.
- the obtained reaction product was passed through a sieve having an opening of 850 ⁇ m to obtain 228.3 g of polymer particles.
- the medium particle size of the polymer particles was 364 ⁇ m. If necessary, polymerization was carried out multiple times in the same manner.
- Production example 5 The amount of ethylene glycol diglycidyl ether as an internal cross-linking agent in the first-stage polymerization reaction was changed to 0.0368 g (0.211 mmol). In the preparation of the second-stage aqueous solution, ethylene was used as an internal cross-linking agent. The use of 0.0515 g (0.296 mmol) of glycol diglycidyl ether, no addition of a cross-linking agent for post-polymerization cross-linking, and co-boiling in the water-containing gel-like polymer after the second stage polymerization. 221.8 g of polymer particles were obtained in the same procedure as in Production Example 1 except that 286.9 g of water was extracted from the system by distillation. The medium particle size of the polymer particles was 396 ⁇ m.
- Production example 6 In the hydrogel polymer after the second stage polymerization, 227.7 g of polymer particles were obtained in the same manner as in Production Example 1 except that 228.7 g of water was extracted from the system by azeotropic distillation. It was. The medium particle size of the polymer particles was 380 ⁇ m.
- Production example 7 In the hydrogel polymer after the second stage polymerization, 221.7 g of polymer particles were obtained in the same manner as in Production Example 1 except that 253.3 g of water was extracted from the system by azeotropic distillation. It was. The medium particle size of the polymer particles was 356 ⁇ m.
- Production Example 8 In the hydrogel polymer after the second stage polymerization, 215.5 g of polymer particles were obtained in the same manner as in Production Example 1 except that 261.5 g of water was extracted from the system by azeotropic distillation. It was. The medium particle size of the polymer particles was 377 ⁇ m.
- Example 1 30 g of the polymer particles obtained in Production Example 1 and 0.15 g of dry silica A (Cabot Japan Co., Ltd., M-5) were mixed to obtain water-absorbent resin particles containing dry silica.
- Example 2 Water-absorbent resin particles of Example 2 were obtained in the same manner as in Example 1 except that the amount of dry silica A (Cabot Japan Co., Ltd., M-5) added was changed to 0.6 g.
- Example 3 The water-absorbent resin particles of Example 3 were obtained in the same manner as in Example 1 except that the dry silica was changed to dry silica B (H300 manufactured by Cabot Japan Co., Ltd.) instead of M-5 manufactured by Cabot Japan Co., Ltd. ..
- Example 4 The water-absorbent resin particles of Example 2 were obtained in the same manner as in Example 3 except that the amount of dry silica B (Cabot Japan Co., Ltd., H300) added was changed to 0.06 g.
- Example 5 The water-absorbent resin particles of Example 5 were obtained in the same manner as in Example 3 except that the amount of dry silica B (Cabot Japan Co., Ltd., H300) added was changed to 0.3 g.
- Example 6 The water-absorbent resin particles of Example 6 were obtained in the same manner as in Example 1 except that the dry silica was changed to dry silica C (M3KD manufactured by Cabot Japan Co., Ltd.) instead of M-5 manufactured by Cabot Japan Co., Ltd. ..
- Example 7 The water-absorbent resin particles of Example 7 were obtained in the same manner as in Example 1 except that the dry silica was changed to dry silica D (Aerosil 200 manufactured by Nippon Aerosil Co., Ltd.) instead of M-5 manufactured by Cabot Japan Co., Ltd. It was.
- dry silica D Adrosil 200 manufactured by Nippon Aerosil Co., Ltd.
- Example 8 The water-absorbent resin particles of Example 8 were obtained in the same manner as in Example 7 except that the amount of dry silica D (Nippon Aerosil Co., Ltd., Aerosil 200) added was changed to 0.06 g.
- dry silica D Natural Aerosil Co., Ltd., Aerosil 200
- Example 9 Water-absorbent resin particles of Example 9 were obtained in the same manner as in Example 7 except that the amount of dry silica D (Nippon Aerosil Co., Ltd., Aerosil 200) added was changed to 0.3 g.
- dry silica D Natural Aerosil Co., Ltd., Aerosil 200
- Example 10 30 g of the polymer particles obtained in Production Example 6 and 0.24 g of dry silica A (Cabot Japan Co., Ltd., M-5) were mixed to obtain water-absorbent resin particles of Example 10.
- Example 11 The water-absorbent resin particles of Example 11 were obtained in the same manner as in Example 10 except that the polymer particles obtained in Production Example 6 were replaced with the polymer particles obtained in Production Example 7.
- Example 12 The water-absorbent resin particles of Example 12 were obtained in the same manner as in Example 10 except that the polymer particles obtained in Production Example 6 were replaced with the polymer particles obtained in Production Example 8.
- Example 13 in the same manner as in Example 1 except that the dry silica A (M-5 manufactured by Cabot Japan Co., Ltd.) was replaced with the dry silica E (OCI Company, Ltd, KONASIL K-200) as the dry silica. Water-absorbent resin particles were obtained.
- Example 14 The water-absorbent resin particles of Example 14 were obtained in the same manner as in Example 13 except that the polymer particles obtained in Production Example 1 were replaced with the polymer particles obtained in Production Example 8.
- Example 15 in the same manner as in Example 1 except that the dry silica A (M-5 manufactured by Cabot Japan Co., Ltd.) was replaced with the dry silica F (OCI Company, Ltd, KONASIL K-150) as the dry silica. Water-absorbent resin particles were obtained.
- Example 16 The water-absorbent resin particles of Example 16 were obtained in the same manner as in Example 15 except that the polymer particles obtained in Production Example 1 were replaced with the polymer particles obtained in Production Example 8.
- Example 17 in the same manner as in Example 1 except that the dry silica A (M-5 manufactured by Cabot Japan Co., Ltd.) was replaced with the dry silica G (Reoloseal QS-102 manufactured by Tokuyama Corporation) as the dry silica. Water-absorbent resin particles were obtained.
- Example 18 The water-absorbent resin particles of Example 18 were obtained in the same manner as in Example 1 except that the polymer particles obtained in Production Example 1 were replaced with the polymer particles obtained in Production Example 9.
- Comparative Example 1 30 g of the polymer particles obtained in Production Example 2 and 0.03 g of wet silica (OSC, Toxil NP-S) were mixed to obtain water-absorbent resin particles containing wet silica.
- OSC wet silica
- Comparative Example 2 30 g of the polymer particles obtained in Production Example 3 and 0.06 g of wet silica (OSC, Toxil NP-S) were mixed to obtain water-absorbent resin particles containing wet silica.
- OSC wet silica
- Comparative Example 3 30 g of the polymer particles obtained in Production Example 4 and 0.06 g of wet silica (OSC, Toxil NP-S) were mixed to obtain water-absorbent resin particles containing wet silica.
- OSC wet silica
- Comparative Example 4 30 g of the polymer particles obtained in Production Example 5 and 0.06 g of wet silica (OSC, Toxil NP-S) were mixed to obtain water-absorbent resin particles containing wet silica.
- OSC wet silica
- Comparative Example 5 30 g of the polymer particles obtained in Production Example 1 and 0.06 g of wet silica (OSC, Toxile NP-S) were mixed with the polymer particles to obtain water-absorbent resin particles containing the wet silica.
- OSC wet silica
- Comparative Example 6 The polymer particles obtained in Production Example 1 without adding dry silica A (Cabot Japan Co., Ltd., M-5) were used as the water-absorbent resin particles of Comparative Example 6.
- the physiological saline water retention amount (room temperature, 25 ° C. ⁇ 2 ° C.) of the water-absorbent resin particles was measured by the following procedure. First, a cotton bag (Membroad No. 60, width 100 mm x length 200 mm) weighing 2.0 g of water-absorbent resin particles was placed in a 500 mL beaker. Pour 500 g of 0.9 mass% sodium chloride aqueous solution (physiological saline) into a cotton bag containing water-absorbent resin particles at a time so that maco cannot be formed, tie the upper part of the cotton bag with a rubber ring, and let it stand for 30 minutes.
- JIS standard sieves have a mesh size of 850 ⁇ 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, a mesh size of 150 ⁇ m, Combined in the order of the saucer.
- Polymer particles (or water-absorbent resin particles) were placed in the best combined sieve and shaken for 20 minutes according to JIS Z8815 (1994) using a low-tap shaker to classify. After classification, the mass of the polymer particles (or water-absorbent resin particles) remaining on each sieve was calculated as a mass percentage with respect to the total amount, and the particle size distribution was determined. By integrating on the sieve in order from the one with the largest particle size with respect to this particle size distribution, the relationship between the mesh size of the sieve and the integrated value of the mass percentage of the polymer particles (or water-absorbent resin particles) remaining on the sieve is logarithmic. Plotted on probability paper. 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 defined as the medium particle size.
- the non-pressurized DW of the water-absorbent resin particles was measured using the measuring device shown in FIG. The measurement was carried out 5 times for one type of water-absorbent resin particles, and the average value of the measured values at three points excluding the minimum value and the maximum value was obtained.
- the measuring device has a burette portion 1, a conduit 5, a measuring table 13, a nylon mesh sheet 15, a frame 11, and a clamp 3.
- the burette portion 1 includes a burette tube 21 on which a scale is described, a rubber stopper 23 for sealing the upper opening of the burette tube 21, a cock 22 connected to the tip of the lower portion of the burette tube 21, and a lower portion of the burette tube 21.
- the burette portion 1 has an air introduction pipe 25 and a cock 24 connected to the burette.
- the burette portion 1 is fixed by a clamp 3.
- the flat plate-shaped measuring table 13 has a through hole 13a having a diameter of 2 mm formed in the central portion thereof, and is supported by a frame 11 having a variable height.
- the through hole 13a of the measuring table 13 and the cock 22 of the burette portion 1 are connected by a conduit 5.
- the inner diameter of the conduit 5 is 6 mm.
- the measurement was performed in an environment with a temperature of 25 ° C and a humidity of 60 ⁇ 10%.
- the concentration of 0.9% by mass of the saline solution is a concentration based on the mass of the saline solution.
- the cock 22 and the cock 24 were opened.
- the inside of the conduit 5 was filled with 0.9% by mass saline solution 50 to prevent air bubbles from entering.
- the height of the measuring table 13 was adjusted so that the height of the water surface of the 0.9% by mass saline solution that reached the inside of the through hole 13a was the same as the height of the upper surface of the measuring table 13. After the adjustment, the height of the water surface of the 0.9 mass% saline solution 50 in the burette tube 21 was read by the scale of the burette tube 21, and the position was set as the zero point (reading value at 0 seconds).
- a nylon mesh sheet 15 (100 mm ⁇ 100 mm, 250 mesh, thickness about 50 ⁇ m) was laid in the vicinity of the through hole 13a on the measuring table 13, and a cylinder having an inner diameter of 30 mm and a height of 20 mm was placed in the center thereof. 1.00 g of water-absorbent resin particles 10a were uniformly sprayed on this cylinder. Then, the cylinder was carefully removed to obtain a sample in which the water-absorbent resin particles 10a were dispersed in a circle in the central portion of the nylon mesh sheet 15.
- the nylon mesh sheet 15 on which the water-absorbent resin particles 10a were placed was quickly moved so that the center thereof was at the position of the through hole 13a so that the water-absorbent resin particles 10a did not dissipate, and the measurement was started. ..
- the time when the air bubbles were first introduced from the air introduction pipe 25 into the burette pipe 21 was defined as the start of water absorption (0 seconds).
- the amount of decrease in the 0.9% by mass saline solution 50 in the bullet tube 21 (that is, the amount of the 0.9% by mass saline solution absorbed by the water-absorbent resin particles 10a) is sequentially read in units of 0.1 mL, and the water-absorbent resin particles are read. 10 seconds, 1 minute, 3 minutes, 5 minutes, and 10 minutes after the start of water absorption of 10a, the weight loss Wc (g) of 0.9% by mass saline solution was read. From Wc, the 10-second value, 1-minute value, 3-minute value, 5-minute value, and 10-minute value of the non-pressurized DW were obtained by the following formula.
- FIG. 3 is a schematic view showing an apparatus for simply evaluating the leakability of an absorber.
- the liquid leakage property of the test absorber was evaluated by the following procedures i), ii), iii), iv) and v).
- a strip-shaped adhesive tape manufactured by Diatex Co., Ltd., Piolan tape
- a strip-shaped adhesive tape having a length of 15 cm and a width of 5 cm is placed on a laboratory table so that the adhesive surface faces up, and the water-absorbent resin particles 3 are placed on the adhesive surface. .0 g was evenly sprayed.
- a stainless steel roller (mass 4.0 kg, diameter 10.5 cm, width 6.0 cm) is placed on top of the sprayed water-absorbent resin particles, and the roller is reciprocated three times between both ends in the longitudinal direction of the adhesive tape. It was. As a result, a water-absorbing layer made of water-absorbent resin particles was formed on the adhesive surface of the adhesive tape (test absorber). ii) The adhesive tape was lifted upright to remove excess water-absorbent resin particles from the water-absorbent layer. Again, the roller was placed on the water absorption layer and reciprocated three times between both ends of the adhesive tape in the longitudinal direction.
- an acrylic resin plate 45 having a rectangular flat main surface S 1 having a length of 30 cm and a width of 55 cm is arranged in a width direction parallel to a horizontal plane S 0 , and the main surface S 1 And the horizontal plane S 0 were fixed so as to form 30 degrees.
- the diffusion distance D is a distance on the main surface connecting the dropping point (injection point) and the longest reaching point with a straight line in the direction perpendicular to the short side of the acrylic resin plate 45.
Landscapes
- Health & Medical Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Public Health (AREA)
- Epidemiology (AREA)
- Engineering & Computer Science (AREA)
- Veterinary Medicine (AREA)
- Life Sciences & Earth Sciences (AREA)
- Animal Behavior & Ethology (AREA)
- General Health & Medical Sciences (AREA)
- Vascular Medicine (AREA)
- Heart & Thoracic Surgery (AREA)
- Biomedical Technology (AREA)
- Hematology (AREA)
- Materials Engineering (AREA)
- Analytical Chemistry (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Inorganic Chemistry (AREA)
- Dispersion Chemistry (AREA)
- Absorbent Articles And Supports Therefor (AREA)
Abstract
The present invention relates to a liquid leakage inhibitor which contains dry silica and is used in an absorbent that contains water absorbent resin particles.
Description
本発明は、吸水性樹脂粒子を含有する吸収体に用いられる液体漏れ抑制剤及び吸水性樹脂粒子に関する。
The present invention relates to a liquid leakage inhibitor and water-absorbent resin particles used for an absorber containing water-absorbent resin particles.
従来、尿等の水を主成分とする液体を吸収するための吸収性物品には、吸水性樹脂粒子を含有する吸収体が用いられている。例えば下記特許文献1には、おしめなどの吸収性物品に好適に用いられる粒子径を有する吸水性樹脂粒子の製造方法が、また特許文献2には、尿の様な体液を収容するのに効果的な吸収性部材として、特定の食塩水流れ誘導性、圧力下性能等を有するヒドロゲル吸収性重合体を使用する方法が開示されている。
Conventionally, an absorber containing water-absorbent resin particles has been used as an absorbent article for absorbing a liquid containing water as a main component such as urine. For example, Patent Document 1 below is effective for producing water-absorbent resin particles having a particle size suitable for absorbent articles such as diapers, and Patent Document 2 is effective for containing body fluids such as urine. A method of using a hydrogel-absorbing polymer having specific saline flow inducibility, performance under pressure, etc. is disclosed as a specific absorbent member.
従来の吸収体を用いた吸収性物品では、吸液対象の液が吸収体に十分吸収されずに、余剰の液が吸収体表面を流れる現象(液走り)が起こりやすく、結果として液が吸収性物品の外に漏れるという、漏れ性の点で改善の余地があった。
In an absorbent article using a conventional absorber, the liquid to be absorbed is not sufficiently absorbed by the absorber, and a phenomenon (liquid running) in which excess liquid flows on the surface of the absorber is likely to occur, and as a result, the liquid is absorbed. There was room for improvement in terms of leakability, which leaked to the outside of the sex article.
本発明は、吸水性樹脂粒子を含有する吸収体に用いられる液体漏れ抑制剤を提供することを目的とする。
An object of the present invention is to provide a liquid leakage inhibitor used for an absorber containing water-absorbent resin particles.
本発明者らは、乾式シリカが、吸水性樹脂粒子を含有する吸収体の液体漏れを抑制する作用を有することを見出した。本発明はこの新規な知見に基づき、乾式シリカの新たな用途を提供するものである。
The present inventors have found that dry silica has an effect of suppressing liquid leakage of an absorber containing water-absorbent resin particles. Based on this novel finding, the present invention provides new uses for dry silica.
本発明の一側面は、乾式シリカを含む、吸水性樹脂粒子を含有する吸収体に用いられる液体漏れ抑制剤に関する。
One aspect of the present invention relates to a liquid leakage inhibitor used for an absorber containing water-absorbent resin particles, including dry silica.
本発明の他の側面は、重合体粒子と、該重合体粒子の表面に配置した上記液体漏れ抑制剤とを含む、吸水性樹脂粒子に関する。本発明の他の側面は、上記吸水性樹脂粒子を含有する吸収体に関する。本発明の他の側面は、上記吸収体を備える、吸収性物品に関する。
Another aspect of the present invention relates to water-absorbent resin particles containing polymer particles and the liquid leakage inhibitor arranged on the surface of the polymer particles. Another aspect of the present invention relates to an absorber containing the water-absorbent resin particles. Another aspect of the invention relates to an absorbent article comprising the absorber.
本発明によれば、吸水性樹脂粒子を含有する吸収体に用いられる液体漏れ抑制剤を提供することができる。
According to the present invention, it is possible to provide a liquid leakage inhibitor used for an absorber containing water-absorbent resin particles.
以下、本発明のいくつかの実施形態について詳細に説明する。ただし、本発明は以下の実施形態に限定されるものではない。
Hereinafter, some embodiments of the present invention will be described in detail. However, the present invention is not limited to the following embodiments.
本明細書において、「アクリル」及び「メタクリル」を合わせて「(メタ)アクリル」と表記する。「アクリレート」及び「メタクリレート」も同様に「(メタ)アクリレート」と表記する。本明細書に段階的に記載されている数値範囲において、ある段階の数値範囲の上限値又は下限値は、他の段階の数値範囲の上限値又は下限値と任意に組み合わせることができる。本明細書に記載されている数値範囲において、その数値範囲の上限値又は下限値は、実施例に示されている値に置き換えてもよい。「A又はB」とは、A及びBのどちらか一方を含んでいればよく、両方とも含んでいてもよい。「水溶性」とは、25℃において水に5質量%以上の溶解性を示すことをいう。本明細書に例示する材料は、単独で用いられてもよく、2種以上を組み合わせて用いられてもよい。組成物中の各成分の含有量は、組成物中に各成分に該当する物質が複数存在する場合、特に断らない限り、組成物中に存在する当該複数の物質の合計量を意味する。
In this specification, "acrylic" and "methacryl" are collectively referred to as "(meth) acrylic". Similarly, "acrylate" and "methacrylate" are also referred to as "(meth) acrylate". In the numerical range described stepwise in the present specification, the upper limit value or the lower limit value of the numerical range of one step can be arbitrarily combined with the upper limit value or the lower limit value of the numerical range of another step. In the numerical range described in the present specification, the upper limit value or the lower limit value of the numerical range may be replaced with the value shown in the examples. "A or B" may include either A or B, or both. "Water-soluble" means that it exhibits a solubility in water of 5% by mass or more at 25 ° C. The materials exemplified in the present specification may be used alone or in combination of two or more. The content of each component in the composition means the total amount of the plurality of substances present in the composition when a plurality of substances corresponding to each component are present in the composition, unless otherwise specified.
<液体漏れ抑制剤>
一実施形態に係る吸水性樹脂粒子を含有する吸収体に用いられる液体漏れ抑制剤は、乾式シリカを含む。吸水性樹脂粒子を含有する吸収体において、乾式シリカを含む液体漏れ抑制剤は、重合体粒子を含む吸水性樹脂粒子の構成成分として用いられる。乾式シリカは、重合体粒子の表面上に配置されていてよい。吸収体に上記液体漏れ抑制剤を含む吸水性樹脂粒子を用いることにより、液体漏れを抑制することができる。 <Liquid leakage inhibitor>
The liquid leakage inhibitor used for the absorber containing the water-absorbent resin particles according to the embodiment includes dry silica. In the absorber containing the water-absorbent resin particles, the liquid leakage inhibitor containing dry silica is used as a constituent component of the water-absorbent resin particles containing the polymer particles. The dry silica may be placed on the surface of the polymer particles. Liquid leakage can be suppressed by using water-absorbent resin particles containing the liquid leakage inhibitor as the absorber.
一実施形態に係る吸水性樹脂粒子を含有する吸収体に用いられる液体漏れ抑制剤は、乾式シリカを含む。吸水性樹脂粒子を含有する吸収体において、乾式シリカを含む液体漏れ抑制剤は、重合体粒子を含む吸水性樹脂粒子の構成成分として用いられる。乾式シリカは、重合体粒子の表面上に配置されていてよい。吸収体に上記液体漏れ抑制剤を含む吸水性樹脂粒子を用いることにより、液体漏れを抑制することができる。 <Liquid leakage inhibitor>
The liquid leakage inhibitor used for the absorber containing the water-absorbent resin particles according to the embodiment includes dry silica. In the absorber containing the water-absorbent resin particles, the liquid leakage inhibitor containing dry silica is used as a constituent component of the water-absorbent resin particles containing the polymer particles. The dry silica may be placed on the surface of the polymer particles. Liquid leakage can be suppressed by using water-absorbent resin particles containing the liquid leakage inhibitor as the absorber.
本発明の液体漏れ抑制剤は、乾式シリカに加えて、湿式シリカ、二酸化チタン、酸化アルミニウム、酸化マグネシウム、酸化亜鉛、リン酸カルシウム、ハイドロタルサイト、ベントナイト、カオリン、タルク、珪藻土、ゼオライト等の無機粒子、ノニオン系界面活性剤、アニオン系界面活性剤、カチオン系界面活性剤、または両性界面活性剤等の界面活性剤、硫酸アルミニウム、硫酸カルシウム、硫酸マグネシウム等の水溶性多価金属塩などが含有されていてもよく、これらの化合物が2種以上を組み合わせて用いられてもよい。これらの化合物は、優れた初期吸水速度を得やすい観点から、親水性を有していてよい。
In addition to dry silica, the liquid leakage inhibitor of the present invention includes wet silica, titanium dioxide, aluminum oxide, magnesium oxide, zinc oxide, calcium phosphate, hydrotalcite, bentonite, kaolin, talc, diatomaceous earth, zeolite and other inorganic particles. Contains nonionic surfactants, anionic surfactants, cationic surfactants, surfactants such as amphoteric surfactants, water-soluble polyvalent metal salts such as aluminum sulfate, calcium sulfate, and magnesium sulfate. You may use these compounds in combination of 2 or more types. These compounds may have hydrophilicity from the viewpoint of easily obtaining an excellent initial water absorption rate.
液体漏れ抑制剤における乾式シリカの含有量が、液体漏れ抑制剤の総質量を基準として70~100質量%、80~100質量%、又は90~100質量%であってもよい。
The content of dry silica in the liquid leakage inhibitor may be 70 to 100% by mass, 80 to 100% by mass, or 90 to 100% by mass based on the total mass of the liquid leakage inhibitor.
本発明に係る乾式シリカは、乾式法によって製造されるシリカであり、例えば、フュームドシリカが挙げられる。乾式シリカは一般的には活性なヒドロキシル基を有しており、そのため親水性を有しているが、そのシリカ表面をアルキルシラン等で表面処理を施すことで疎水性を付与することもできる。優れた初期吸水速度を得やすい観点から、乾式シリカは、親水性を有していてよい。
The dry silica according to the present invention is silica produced by a dry method, and examples thereof include fumed silica. Dry silica generally has an active hydroxyl group and is therefore hydrophilic, but the surface of the silica can be surface-treated with alkylsilane or the like to impart hydrophobicity. From the viewpoint of easily obtaining an excellent initial water absorption rate, the dry silica may have hydrophilicity.
本発明に係る乾式シリカは、ナノメートルサイズの一次粒子を構成単位とし、複数の一次粒子が集合して形成された二次粒子の形態を採っている。更に、乾式シリカでは、複数の二次粒子が会合して、二次粒子の会合体である二次凝集体が形成される。乾式シリカと、乾式シリカ以外の合成非晶質シリカ(例えば、湿式法によって製造される湿式シリカ)とでは、例えば、凝集体の形状が異なっている。一般的に、湿式シリカの凝集体は、ほぼ球形の凝集構造を有するとされているのに対し、乾式シリカの凝集体は、鎖状の凝集構造を有する。
The dry silica according to the present invention has a nanometer-sized primary particle as a constituent unit, and takes the form of a secondary particle formed by aggregating a plurality of primary particles. Further, in dry silica, a plurality of secondary particles are associated to form a secondary aggregate which is an aggregate of secondary particles. For example, the shape of the agglomerates is different between dry silica and synthetic amorphous silica other than dry silica (for example, wet silica produced by a wet method). In general, wet silica aggregates are said to have a substantially spherical aggregate structure, whereas dry silica aggregates have a chain-like aggregate structure.
本発明に係る乾式シリカの比表面積は、例えば、50m2/g以上、75m2/g以上、100m2/g以上、125m2/g以上、150m2/g以上、170m2/g以上、又は200m2/g以上であってよく、1000m2/g以下、800m2/g以下、600m2/g以下、400m2/g以下、又は350m2/g以下であってよい。乾式シリカの比表面積は、例えば、50~1000m2/g、75~600m2/g、又は100~400m2/gであってよい。乾式シリカの比表面積は、BET比表面積(N2)法によって測定することができる。
The specific surface area of the dry silica according to the present invention is, for example, 50 m 2 / g or more, 75 m 2 / g or more, 100 m 2 / g or more, 125 m 2 / g or more, 150 m 2 / g or more, 170 m 2 / g or more, or It may be 200 m 2 / g or more, 1000 m 2 / g or less, 800 m 2 / g or less, 600 m 2 / g or less, 400 m 2 / g or less, or 350 m 2 / g or less. The specific surface area of the dry silica may be, for example, 50 to 1000 m 2 / g, 75 to 600 m 2 / g, or 100 to 400 m 2 / g. The specific surface area of dry silica can be measured by the BET specific surface area (N 2) method.
本発明に係る乾式シリカの嵩密度は、例えば、10~200g/Lであってよい。優れた吸水特性が得やすい観点から、乾式シリカの嵩密度は、10g/L以上、20g/L以上、30g/L以上、又は40g/L以上であってよく、200g/L以下、180g/L以下、150g/L以下、130g/L以下、100g/L以下、90g/L以下、又は80g/L以下であってもよい。シリカの嵩密度は、顔料試験方法(JIS-K5101-12-1)や後述の粉体特性評価装置を用いることによって測定することができる。
The bulk density of the dry silica according to the present invention may be, for example, 10 to 200 g / L. From the viewpoint that excellent water absorption characteristics can be easily obtained, the bulk density of the dry silica may be 10 g / L or more, 20 g / L or more, 30 g / L or more, or 40 g / L or more, and 200 g / L or less, 180 g / L or more. Hereinafter, it may be 150 g / L or less, 130 g / L or less, 100 g / L or less, 90 g / L or less, or 80 g / L or less. The bulk density of silica can be measured by using a pigment test method (JIS-K5101-12-1) or a powder property evaluation device described later.
本発明に係る乾式シリカの一次粒子の平均粒子径(一次平均粒子径)は、取扱い性及び吸水性樹脂粒子表面への付着性の観点から、5nm以上、7nm以上、10nm以上、又は12nm以上であってよく、500nm以下、100nm以下、50nm以下、30nm以下、又は20nm以下であってよい。より具体的には、乾式シリカの一次平均粒子径は、5nm以上500nm以下であってよく、7nm以上50nm以下であってよい。シリカの平均一次粒子径は、透過型電子顕微鏡による観察によって測定することができる。
The average particle size (primary average particle size) of the primary particles of the dry silica according to the present invention is 5 nm or more, 7 nm or more, 10 nm or more, or 12 nm or more from the viewpoint of handleability and adhesion to the surface of the water-absorbent resin particles. It may be 500 nm or less, 100 nm or less, 50 nm or less, 30 nm or less, or 20 nm or less. More specifically, the primary average particle size of the dry silica may be 5 nm or more and 500 nm or less, and may be 7 nm or more and 50 nm or less. The average primary particle size of silica can be measured by observation with a transmission electron microscope.
本発明に係る乾式シリカの二次凝集粒子の平均粒子径は、取扱い性及び優れた吸水特性を得やすい観点から、1.0μm以上、10μm以上、又は20μm以上であってよく、100μm以下、70μm以下、又は50μm以下であってもよい。同様の観点から、より具体的には、乾式シリカの二次凝集粒子の平均粒子径は、1.0μm以上100μm以下、10μm以上70μm以下であってよい。シリカの二次凝集粒子の平均粒子径は、動的光散乱法、レーザー回折・散乱法又はコールターカウンター法によって測定することができる。
The average particle size of the secondary agglomerated particles of the dry silica according to the present invention may be 1.0 μm or more, 10 μm or more, or 20 μm or more, and 100 μm or less, 70 μm, from the viewpoint of easy handling and excellent water absorption characteristics. It may be less than or equal to 50 μm or less. From the same viewpoint, more specifically, the average particle size of the secondary agglomerated particles of the dry silica may be 1.0 μm or more and 100 μm or less, and 10 μm or more and 70 μm or less. The average particle size of the secondary agglomerated particles of silica can be measured by a dynamic light scattering method, a laser diffraction / scattering method, or a Coulter counter method.
本発明に係る乾式シリカの含水率は、例えば、10質量%以下、5.0質量%以下、3.0質量%以下、又は2.0質量%以下であってよい。乾式シリカの含水率の下限は例えば、0.01質量%以上、0.05質量%以上、又は0.1質量%以上であってよい。乾式シリカは含水率が5質量%以下であるフュームドシリカであってよい。乾式シリカの含水率は、顔料及び体質顔料一般試験方法ISO787-2によって測定することができる。本明細書における乾式シリカの含水率は、乾式シリカ及び該乾式シリカ中の水の合計質量を基準とする含水率である。
The water content of the dry silica according to the present invention may be, for example, 10% by mass or less, 5.0% by mass or less, 3.0% by mass or less, or 2.0% by mass or less. The lower limit of the water content of the dry silica may be, for example, 0.01% by mass or more, 0.05% by mass or more, or 0.1% by mass or more. The dry silica may be fumed silica having a water content of 5% by mass or less. The water content of the dry silica can be measured by the general test method ISO787-2 for pigments and extender pigments. The water content of the dry silica in the present specification is a water content based on the total mass of the dry silica and the water in the dry silica.
乾式シリカ(親水性の乾式シリカ)としては、例えば、日本アエロジル株式会社製「アエロジル200」、「アエロジル300」、「アエロジル380」、キャボットジャパン株式会社製「CAB-O-SIL M-5」、「CAB-O-SIL H-300」、「CAB-O-SIL M-5」、「CAB-O-SIL M3KD」、OCI Company,Ltd製「KONASIL K-200」、「KONASIL K-150」、株式会社トクヤマ製「レオロシール QS-102」として販売されているものを用いることができる。これらは一種単独で用いられてもよく、二種以上を組み合わせて用いられてもよい。
Examples of dry silica (hydrophilic dry silica) include "Aerosil 200", "Aerosil 300", "Aerosil 380" manufactured by Nippon Aerosil Co., Ltd., and "CAB-O-SIL M-5" manufactured by Cabot Japan Co., Ltd. "CAB-O-SIL H-300", "CAB-O-SIL M-5", "CAB-O-SIL M3KD", OCI Company, Ltd. "KONASIL K-200", "KONASIL K-150", The one sold as "Leolosil QS-102" manufactured by Tokuyama Corporation can be used. These may be used alone or in combination of two or more.
<吸水性樹脂粒子>
本実施形態に係る吸水性樹脂粒子は、重合体粒子と、該重合体粒子の表面に配置された上述の液体漏れ抑制剤と、を含んでいてよい。例えば、重合体粒子と液体漏れ抑制剤とを混合することにより、重合体粒子の表面上に液体漏れ抑制剤を配置することができる。 <Water-absorbent resin particles>
The water-absorbent resin particles according to the present embodiment may contain polymer particles and the above-mentioned liquid leakage inhibitor arranged on the surface of the polymer particles. For example, by mixing the polymer particles and the liquid leakage inhibitor, the liquid leakage inhibitor can be arranged on the surface of the polymer particles.
本実施形態に係る吸水性樹脂粒子は、重合体粒子と、該重合体粒子の表面に配置された上述の液体漏れ抑制剤と、を含んでいてよい。例えば、重合体粒子と液体漏れ抑制剤とを混合することにより、重合体粒子の表面上に液体漏れ抑制剤を配置することができる。 <Water-absorbent resin particles>
The water-absorbent resin particles according to the present embodiment may contain polymer particles and the above-mentioned liquid leakage inhibitor arranged on the surface of the polymer particles. For example, by mixing the polymer particles and the liquid leakage inhibitor, the liquid leakage inhibitor can be arranged on the surface of the polymer particles.
液体漏れ抑制剤の含有量は、重合体粒子の質量100質量部に対して、0.2質量部以上、0.35質量部以上、0.5質量部以上、1.0質量部以上、又は1.5質量部以上であってもよく、5.0質量部以下、3.5質量部以下、又は2.5質量部以下であってもよい。乾式シリカの含有量が、上記液体漏れ抑制剤の含有量に記載の範囲内であってよい。液体漏れ抑制剤の含有量及び/又は乾式シリカの含有量が上記範囲内であると、液体漏れ抑制効果がより一層優れたものとなる。
The content of the liquid leakage inhibitor is 0.2 parts by mass or more, 0.35 parts by mass or more, 0.5 parts by mass or more, 1.0 parts by mass or more, or more than 100 parts by mass of the polymer particles. It may be 1.5 parts by mass or more, 5.0 parts by mass or less, 3.5 parts by mass or less, or 2.5 parts by mass or less. The content of the dry silica may be within the range described in the content of the liquid leakage inhibitor. When the content of the liquid leakage inhibitor and / or the content of the dry silica is within the above range, the liquid leakage suppression effect becomes even more excellent.
一実施形態に係る吸水性樹脂粒子の無加圧DWの10秒値及び3分値から下記の吸水速度指数係数I及びIIを求めたときに、
吸水速度指数I=(無加圧DWの10秒値)×6[mL/g]
吸水速度指数II=(無加圧DWの3分値)/3[mL/g]
下記式:
α=(I+II)/2
で算出される静的吸引指数αが5.0mL/g以上であってよい。 When the following water absorption rate index coefficients I and II were obtained from the 10-second value and 3-minute value of the non-pressurized DW of the water-absorbent resin particles according to one embodiment,
Water absorption rate index I = (10-second value of non-pressurized DW) x 6 [mL / g]
Water absorption rate index II = (3 minutes value of non-pressurized DW) / 3 [mL / g]
The following formula:
α = (I + II) / 2
The static suction index α calculated in 1 may be 5.0 mL / g or more.
吸水速度指数I=(無加圧DWの10秒値)×6[mL/g]
吸水速度指数II=(無加圧DWの3分値)/3[mL/g]
下記式:
α=(I+II)/2
で算出される静的吸引指数αが5.0mL/g以上であってよい。 When the following water absorption rate index coefficients I and II were obtained from the 10-second value and 3-minute value of the non-pressurized DW of the water-absorbent resin particles according to one embodiment,
Water absorption rate index I = (10-second value of non-pressurized DW) x 6 [mL / g]
Water absorption rate index II = (3 minutes value of non-pressurized DW) / 3 [mL / g]
The following formula:
α = (I + II) / 2
The static suction index α calculated in 1 may be 5.0 mL / g or more.
無加圧DWは、吸水性樹脂粒子が、無加圧下で、生理食塩水(濃度0.9質量%の食塩水)と接触してから所定の時間経過するまでに生理食塩水を吸収した量で表される吸水速度である。無加圧DWは、生理食塩水の吸収前の吸水性樹脂粒子1g当たりの吸収量(mL)で表される。無加圧DWの10秒値及び3分値は、それぞれ、吸水性樹脂粒子が生理食塩水と接触してから10秒後及び3分後の吸収量を意味する。吸水速度指数I及びIIは、無加圧DWの10秒値及び3分値を、1分当たりの吸水速度に換算した値に相当する。静的吸引指数αは、吸水速度指数I及びIIの平均値に相当し、静的吸引指数αが大きいことは、10秒から3分の間にわたって比較的大きな吸水速度が維持されることを意味する。本発明者の知見によれば、吸水性樹脂粒子の静的吸引指数αが5.0mL/g以上である場合、液体漏れがより一層効果的に抑制される。
The non-pressurized DW is the amount of the water-absorbent resin particles that have absorbed the physiological saline solution within a predetermined time after the contact with the physiological saline solution (saline solution having a concentration of 0.9% by mass) under no pressurization. It is the water absorption rate represented by. The non-pressurized DW is represented by the absorption amount (mL) per 1 g of the water-absorbent resin particles before the absorption of the physiological saline. The 10-second value and the 3-minute value of the non-pressurized DW mean the amount of absorption 10 seconds and 3 minutes after the water-absorbent resin particles come into contact with the physiological saline solution, respectively. The water absorption rate indexes I and II correspond to the values obtained by converting the 10-second value and the 3-minute value of the non-pressurized DW into the water absorption rate per minute. The static suction index α corresponds to the average value of the water absorption rate indexes I and II, and a large static suction index α means that a relatively large water absorption rate is maintained for 10 seconds to 3 minutes. To do. According to the findings of the present inventor, when the static suction index α of the water-absorbent resin particles is 5.0 mL / g or more, liquid leakage is suppressed more effectively.
静的吸引指数αが大きいと、吸水性樹脂粒子による液体漏れがより一層効果的に抑制される傾向がある。静的吸引指数αは6.0mL/g以上、7.0mL/g以上、9.0mL/g以上、10mL/g以上、11mL/g以上、12mL/g以上、13mL/g以上、14mL/g以上、又は15mL/g以上であってもよい。静的吸引指数αの上限は、通常、25mL/g以下、又は20mL/g以下である。
When the static suction index α is large, liquid leakage due to water-absorbent resin particles tends to be suppressed more effectively. Static suction index α is 6.0 mL / g or more, 7.0 mL / g or more, 9.0 mL / g or more, 10 mL / g or more, 11 mL / g or more, 12 mL / g or more, 13 mL / g or more, 14 mL / g It may be more than or equal to 15 mL / g or more. The upper limit of the static suction index α is usually 25 mL / g or less, or 20 mL / g or less.
吸水速度指数Iは、2mL/g以上、4mL/g以上、6mL/g以上、又は8mL/g以上であってもよく、30mL/g以下、又は25mL/g以下であってもよい。吸水速度指数IIは、8mL/g以上、12mL/g以上、又は16mL/g以上であってもよく、30mL/g以下、又は25mL/g以下であってもよい。吸水速度指数I及びIIがこれら数値範囲内であると、静的吸引指数αが5.0mL/gとなり易い。
The water absorption rate index I may be 2 mL / g or more, 4 mL / g or more, 6 mL / g or more, or 8 mL / g or more, and may be 30 mL / g or less, or 25 mL / g or less. The water absorption rate index II may be 8 mL / g or more, 12 mL / g or more, 16 mL / g or more, 30 mL / g or less, or 25 mL / g or less. When the water absorption rate indexes I and II are within these numerical ranges, the static suction index α tends to be 5.0 mL / g.
5.0mL/g以上の静的吸引指数αを示す吸水性樹脂粒子は、例えば、重合体粒子に液体漏れ抑制剤を配置させ、その量を調整すること、重合体粒子の表面積を大きくすること、重合体粒子の表層における架橋密度を調整すること、又はこれらの組み合わせにより、得ることができる。
For the water-absorbent resin particles showing a static suction index α of 5.0 mL / g or more, for example, the liquid leakage inhibitor is arranged on the polymer particles, the amount thereof is adjusted, and the surface area of the polymer particles is increased. , The crosslink density in the surface layer of the polymer particles can be adjusted, or a combination thereof can be obtained.
本実施形態に係る吸水性樹脂粒子の生理食塩水の保水量は、例えば、20g/g以上、25g/g以上、30g/g以上、32g/g以上、34g/g以上、36g/g以上、38g/g以上、又は39g/g以上であってもよく、60g/g以下、55g/g以下、50g/g以下、45g/g以下、又は42g/g以下であってもよい。本実施形態に係る吸水性樹脂粒子の生理食塩水の保水量は、20~60g/g、25~60g/g、30~55g/g、又は32~55g/gであってよい。生理食塩水の保水量は、後述する実施例に記載の方法によって測定される。
The water-retaining amount of the physiological saline of the water-absorbent resin particles according to the present embodiment is, for example, 20 g / g or more, 25 g / g or more, 30 g / g or more, 32 g / g or more, 34 g / g or more, 36 g / g or more. It may be 38 g / g or more, 39 g / g or more, 60 g / g or less, 55 g / g or less, 50 g / g or less, 45 g / g or less, or 42 g / g or less. The water-retaining amount of the physiological saline of the water-absorbent resin particles according to the present embodiment may be 20 to 60 g / g, 25 to 60 g / g, 30 to 55 g / g, or 32 to 55 g / g. The amount of physiological saline retained is measured by the method described in Examples described later.
本実施形態に係る吸水性樹脂粒子の形状としては、略球状、破砕状若しくは顆粒状、又はこれらの形状を有する一次粒子が凝集して形成された形状等が挙げられる。
Examples of the shape of the water-absorbent resin particles according to the present embodiment include a substantially spherical shape, a crushed shape, a granular shape, and a shape formed by aggregating primary particles having these shapes.
重合体粒子は、エチレン性不飽和単量体を単量体単位として含む重合体を含有する吸水性の粒子であってもよい。エチレン性不飽和単量体は、水溶性の単量体であってもよく、その例としては、(メタ)アクリル酸及びその塩、2-(メタ)アクリルアミド-2-メチルプロパンスルホン酸及びその塩、(メタ)アクリルアミド、N,N-ジメチル(メタ)アクリルアミド、2-ヒドロキシエチル(メタ)アクリレート、N-メチロール(メタ)アクリルアミド、ポリエチレングリコールモノ(メタ)アクリレート、N,N-ジエチルアミノエチル(メタ)アクリレート、N,N-ジエチルアミノプロピル(メタ)アクリレート、並びにジエチルアミノプロピル(メタ)アクリルアミドが挙げられる。エチレン性不飽和単量体は、単独で用いられてもよく、2種以上を組み合わせて用いられてもよい。重合体粒子における、エチレン性不飽和単量体を単量体単位として含む重合体の割合は、重合体粒子の質量を基準として50~100質量%、60~100質量%、70~100質量%、又は80~100質量%であってもよい。重合体粒子は、(メタ)アクリル酸又は(メタ)アクリル酸塩のうち少なくとも一方を単量体単位として含む(メタ)アクリル酸系重合体を含有する粒子であってもよい。(メタ)アクリル酸系重合体における(メタ)アクリル酸又は(メタ)アクリル酸塩に由来する単量体単位の合計の割合は、重合体の質量を基準として90~100質量%であってもよい。
The polymer particles may be water-absorbent 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. Salt, (meth) acrylamide, N, N-dimethyl (meth) acrylamide, 2-hydroxyethyl (meth) acrylate, N-methylol (meth) acrylamide, polyethylene glycol mono (meth) acrylate, N, N-diethylaminoethyl (meth) ) Acrylate, N, N-diethylaminopropyl (meth) acrylate, and diethylaminopropyl (meth) acrylamide. The ethylenically unsaturated monomer may be used alone or in combination of two or more. The proportion of the polymer containing the ethylenically unsaturated monomer as a monomer unit in the polymer particles is 50 to 100% by mass, 60 to 100% by mass, and 70 to 100% by mass based on the mass of the polymer particles. , Or 80 to 100% by mass. The polymer particles may be particles containing a (meth) acrylic acid-based polymer containing at least one of (meth) acrylic acid or (meth) acrylate as a monomer unit. The total ratio of the monomer units derived from (meth) acrylic acid or (meth) acrylate in the (meth) acrylic acid-based polymer may be 90 to 100% by mass based on the mass of the polymer. Good.
重合体粒子のうち少なくとも表層部分の重合体は、表面架橋剤との反応によって架橋されていてよい。表面架橋剤は、例えば、エチレン性不飽和単量体由来の官能基との反応性を有する官能基(反応性官能基)を2個以上有する化合物であってよい。表面架橋剤としては、例えば、エチレンカーボネート、プロピレンカーボネート等のアルキレンカーボネート化合物;エチレングリコール、プロピレングリコール、1,4-ブタンジオール、トリメチロールプロパン、グリセリン、ポリオキシエチレングリコール、ポリオキシプロピレングリコール、ポリグリセリン等のポリオール類;(ポリ)エチレングリコールジグリシジルエーテル、(ポリ)グリセリンジグリシジルエーテル、(ポリ)グリセリントリグリシジルエーテル、(ポリ)プロピレングリコールポリグリシジルエーテル、(ポリ)グリセロールポリグリシジルエーテル等のポリグリシジル化合物;エピクロルヒドリン、エピブロムヒドリン、α-メチルエピクロルヒドリン等のハロエポキシ化合物;2,4-トリレンジイソシアネート、ヘキサメチレンジイソシアネート等のイソシアネート化合物等の反応性官能基を2個以上有する化合物;3-メチル-3-オキセタンメタノール、3-エチル-3-オキセタンメタノール、3-ブチル-3-オキセタンメタノール、3-メチル-3-オキセタンエタノール、3-エチル-3-オキセタンエタノール、3-ブチル-3-オキセタンエタノール等のオキセタン化合物;1,2-エチレンビスオキサゾリン等のオキサゾリン化合物;ビス[N,N-ジ(β-ヒドロキシエチル)]アジプアミド等のヒドロキシアルキルアミド化合物等が挙げられる。表面架橋剤が、ポリグリシジル化合物を含んでいてもよい。表面架橋剤におけるポリグリシジル化合物の比率が、表面架橋剤の総質量を基準として50~100質量%、60~100質量%、70~100質量%、80~100質量%、又は90~100質量%であってもよい。
Of the polymer particles, at least the polymer in the surface layer portion may be crosslinked by the reaction with the surface cross-linking agent. The surface cross-linking agent may be, for example, a compound having two or more functional groups (reactive functional groups) having reactivity with a functional group derived from an ethylenically unsaturated monomer. Examples of the surface cross-linking agent include alkylene carbonate compounds such as ethylene carbonate and propylene carbonate; ethylene glycol, propylene glycol, 1,4-butanediol, trimethylolpropane, glycerin, polyoxyethylene glycol, polyoxypropylene glycol, and polyglycerin. Polysaccharides such as (poly) ethylene glycol diglycidyl ether, (poly) glycerin diglycidyl ether, (poly) glycerin triglycidyl ether, (poly) propylene glycol polyglycidyl ether, (poly) glycerol polyglycidyl ether and the like. Compounds; Haloepoxy compounds such as epichlorohydrin, epibromhydrin, α-methylepicrolhydrin; compounds having two or more reactive functional groups such as isocyanate compounds such as 2,4-tolylene diisocyanate and hexamethylene diisocyanate; 3-methyl- 3-Oxetane methanol, 3-ethyl-3-oxetane methanol, 3-butyl-3-oxetane methanol, 3-methyl-3-oxetane ethanol, 3-ethyl-3-oxetane ethanol, 3-butyl-3-oxetane ethanol, etc. Oxetane compounds; oxazoline compounds such as 1,2-ethylenebisoxazoline; hydroxyalkylamide compounds such as bis [N, N-di (β-hydroxyethyl)] adipamide and the like. The surface cross-linking agent may contain a polyglycidyl compound. The ratio of the polyglycidyl compound in the surface cross-linking agent is 50 to 100% by mass, 60 to 100% by mass, 70 to 100% by mass, 80 to 100% by mass, or 90 to 100% by mass based on the total mass of the surface cross-linking agent. It may be.
重合体粒子の内部においても、重合体が、自己架橋、内部架橋剤との反応による架橋、又はこれらの両方によって内部架橋されていてもよい。吸水特性の制御のしやすさの観点から、少なくとも内部架橋剤による反応が含まれていてよい。
Even inside the polymer particles, the polymer may be internally crosslinked by self-crosslinking, cross-linking by reaction with an internal cross-linking agent, or both. From the viewpoint of ease of control of water absorption characteristics, at least a reaction by an internal cross-linking agent may be included.
内部架橋剤は、例えば、重合性不飽和基を2個以上有する化合物、エチレン性不飽和単量体が有する官能基との反応性を有する反応性官能基を2個以上有する化合物、又はこれらの組み合わせを含む1種又は2種以上の化合物を含むことができる。
The internal cross-linking agent is, for example, a compound having two or more polymerizable unsaturated groups, a compound having two or more reactive functional groups having reactivity with a functional group of an ethylenically unsaturated monomer, or a compound thereof. It can contain one or more compounds, including combinations.
重合性不飽和基を2個以上有する化合物の例としては、(ポリ)エチレングリコール(本明細書において、例えば、「ポリエチレングリコール」と「エチレングリコール」を合わせて「(ポリ)エチレングリコール」と記す。以下同様)、(ポリ)プロピレングリコール、トリメチロールプロパン、グリセリンポリオキシエチレングリコール、ポリオキシプロピレングリコール、及び(ポリ)グリセリン等のポリオール類のジ又はトリ(メタ)アクリル酸エステル類;上記ポリオールとマレイン酸及びフマル酸等の不飽和酸類とを反応させて得られる不飽和ポリエステル類;N,N’-メチレンビス(メタ)アクリルアミド等のビスアクリルアミド類;ポリエポキシドと(メタ)アクリル酸とを反応させて得られるジ又はトリ(メタ)アクリル酸エステル類;トリレンジイソシアネートやヘキサメチレンジイソシアネート等のポリイソシアネートと(メタ)アクリル酸ヒドロキシエチルとを反応させて得られるジ(メタ)アクリル酸カルバミルエステル類;アリル化澱粉;アリル化セルロース;ジアリルフタレート;N,N’,N’’-トリアリルイソシアヌレート;ジビニルベンゼンが挙げられる。
As an example of a compound having two or more polymerizable unsaturated groups, (poly) ethylene glycol (in this specification, for example, "polyethylene glycol" and "ethylene glycol" are collectively referred to as "(poly) ethylene glycol". Di or tri (meth) acrylic acid esters of polyols such as (poly) propylene glycol, trimethylolpropane, glycerin polyoxyethylene glycol, polyoxypropylene glycol, and (poly) glycerin; Unsaturated polyesters obtained by reacting with unsaturated acids such as maleic acid and fumaric acid; bisacrylamides such as N, N'-methylenebis (meth) acrylamide; by reacting polyepoxide with (meth) acrylic acid. Di or tri (meth) acrylic acid esters obtained; di (meth) acrylic acid carbamil esters obtained by reacting polyisocyanates such as tolylene diisocyanate and hexamethylene diisocyanate with hydroxyethyl (meth) acrylic acid; Alylated starch; allylated cellulose; diallyl phthalate; N, N', N''-triallyl isocyanurate; divinylbenzene.
反応性官能基を2個以上有する化合物の例としては、(ポリ)エチレングリコールジグリシジルエーテル、(ポリ)プロピレングリコールジグリシジルエーテル、及び(ポリ)グリセリンジグリシジルエーテル等のグリシジル基含有化合物;(ポリ)エチレングリコール、(ポリ)プロピレングリコール、(ポリ)グリセリン、ペンタエリスリトール、エチレンジアミン、ポリエチレンイミン、グリシジル(メタ)アクリレートが挙げられる。
Examples of compounds having two or more reactive functional groups include glycidyl group-containing compounds such as (poly) ethylene glycol diglycidyl ether, (poly) propylene glycol diglycidyl ether, and (poly) glycerin diglycidyl ether; (poly). ) Ethylene glycol, (poly) propylene glycol, (poly) glycerin, pentaerythritol, ethylenediamine, polyethyleneimine, glycidyl (meth) acrylate.
重合体粒子は、重合後架橋を施されていてもよい。例えば、重合体に架橋剤を添加して加熱することで、重合後架橋を行うことができる。重合後架橋を行うことで、重合体の架橋度を高め、それにより吸水性樹脂粒子の吸水特性を更に向上させることができる。
The polymer particles may be crosslinked after polymerization. For example, by adding a cross-linking agent to the polymer and heating it, cross-linking can be performed after the polymerization. By performing cross-linking after polymerization, the degree of cross-linking of the polymer can be increased, whereby the water-absorbing characteristics of the water-absorbent resin particles can be further improved.
重合後架橋を行うための架橋剤としては、例えば、エチレングリコール、プロピレングリコール、1,4-ブタンジオール、トリメチロールプロパン、グリセリン、ポリオキシエチレングリコール、ポリオキシプロピレングリコール、ポリグリセリン等のポリオール;(ポリ)エチレングリコールジグリシジルエーテル、(ポリ)プロピレングリコールジグリシジルエーテル、及び(ポリ)グリセリンジグリシジルエーテル等の2個以上のエポキシ基を有する化合物;エピクロルヒドリン、エピブロムヒドリン、及びα-メチルエピクロルヒドリン等のハロエポキシ化合物;2,4-トリレンジイソシアネート、及びヘキサメチレンジイソシアネート等の2個以上のイソシアネート基を有する化合物;1,2-エチレンビスオキサゾリン等のオキサゾリン化合物;エチレンカーボネート、プロピレンカーボネート等のカーボネート化合物;ビス[N,N-ジ(β-ヒドロキシエチル)]アジプアミド等のヒドロキシアルキルアミド化合物等が挙げられる。重合後架橋のための架橋剤が、(ポリ)エチレングリコールジグリシジルエーテル、(ポリ)グリセリンジグリシジルエーテル、(ポリ)グリセリントリグリシジルエーテル、(ポリ)プロピレングリコールポリグリシジルエーテル、及びポリグリセロールポリグリシジルエーテル等のポリグリシジル化合物であってもよい。これらの架橋剤は、単独で用いられてもよいし、2種以上を組み合わせて用いられてもよい。重合後架橋剤が、ポリグリシジル化合物を含んでいてもよい。重合後架橋剤におけるポリグリシジル化合物の比率が、重合後架橋剤の総質量を基準として50~100質量%、60~100質量%、70~100質量%、80~100質量%、又は90~100質量%であってもよい。
Examples of the cross-linking agent for performing post-polymerization cross-linking 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; 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 ethylene carbonate and propylene carbonate; Examples thereof include hydroxyalkylamide compounds such as bis [N, N-di (β-hydroxyethyl)] adipamide. 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 post-polymerization cross-linking agent may contain a polyglycidyl compound. The ratio of the polyglycidyl compound in the post-polymerization cross-linking agent is 50 to 100% by mass, 60 to 100% by mass, 70 to 100% by mass, 80 to 100% by mass, or 90 to 100% based on the total mass of the post-polymerization cross-linking agent. It may be% by mass.
重合後架橋の添加時期としては、重合に用いられるエチレン性不飽和単量体の重合後であればよく、多段重合の場合は、多段重合後に添加されてよい。なお、重合時及び重合後の発熱、工程遅延による滞留、架橋剤添加時の系の開放、並びに、架橋剤添加に伴う水の添加等による水分の変動を考慮して、重合後架橋の架橋剤は、含水率(含水ゲル状重合体の質量を基準とする水の含有量)の観点から、[重合直後の含水率±3%]の領域で添加されてもよい。
The time for adding the cross-linking after the polymerization may be after the polymerization of the ethylenically unsaturated monomer used for the polymerization, and in the case of the multi-stage polymerization, it may be added after the multi-stage polymerization. In consideration of heat generation during and after polymerization, retention due to process delay, opening of the system when a cross-linking agent is added, and fluctuation of water content due to addition of water due to addition of a cross-linking agent, a cross-linking agent for post-polymerization cross-linking. May be added in the region of [water content immediately after polymerization ± 3%] from the viewpoint of water content (water content based on the mass of the water-containing gel-like polymer).
重合体粒子の中位粒子径は、130~800μm、200~850μm、250~700μm、300~600μm、又は、300~450μmであってよい。重合体粒子は、後述する製造方法により得られた時点で所望の粒度分布を有していてよいが、篩による分級を用いた粒度調整等の操作を行うことにより粒度分布を調整してもよい。
The medium particle size of the polymer particles may be 130 to 800 μm, 200 to 850 μm, 250 to 700 μm, 300 to 600 μm, or 300 to 450 μm. The polymer 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. ..
重合体粒子は、エチレン性不飽和単量体の重合体に加えて、ある程度の水分を含んでいてもよく、その内部に各種の追加の成分を更に含んでいてもよい。追加の成分の例としては、ゲル安定剤、金属キレート剤、抗菌剤等が挙げられる。
The polymer particles may contain a certain amount of water in addition to the polymer of the ethylenically unsaturated monomer, and may further contain various additional components therein. Examples of additional ingredients include gel stabilizers, metal chelating agents, antibacterial agents and the like.
(吸水性樹脂粒子を製造する方法)
以上例示された実施形態に係る吸水性樹脂粒子は、例えば、重合体粒子の表面に上記液体漏れ抑制剤を配置させる工程を備える方法によって、製造することができる。 (Method of manufacturing water-absorbent resin particles)
The water-absorbent resin particles according to the above-exemplified embodiments can be produced, for example, by a method including a step of arranging the liquid leakage inhibitor on the surface of the polymer particles.
以上例示された実施形態に係る吸水性樹脂粒子は、例えば、重合体粒子の表面に上記液体漏れ抑制剤を配置させる工程を備える方法によって、製造することができる。 (Method of manufacturing water-absorbent resin particles)
The water-absorbent resin particles according to the above-exemplified embodiments can be produced, for example, by a method including a step of arranging the liquid leakage inhibitor on the surface of the polymer particles.
重合体粒子は、例えば、エチレン性不飽和単量体を含む単量体を重合する工程を含む方法によって、得ることができる。単量体の重合方法は、例えば、逆相懸濁重合法、水溶液重合法、バルク重合法、及び沈殿重合法から選択され得る。エチレン性不飽和単量体を内部架橋剤の存在下で重合することによって、架橋剤により内部架橋された重合体粒子を得てもよい。エチレン性不飽和単量体をシリカ等の無機粒子の存在下で重合することによって、無機粒子を内部に含む重合体粒子を得てもよい。エチレン系不飽和単量体のうち一部又は全部が、アルカリ金属塩等の塩を形成していてもよい。
The polymer particles can be obtained, for example, by a method including a step of polymerizing a monomer containing an ethylenically unsaturated monomer. The polymerization method of the monomer 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. By polymerizing the ethylenically unsaturated monomer in the presence of an internal cross-linking agent, polymer particles internally cross-linked by the cross-linking agent may be obtained. Polymer particles containing inorganic particles may be obtained by polymerizing an ethylenically unsaturated monomer in the presence of inorganic particles such as silica. A part or all of the ethylene-based unsaturated monomer may form a salt such as an alkali metal salt.
水溶液重合法の場合、例えば、エチレン性不飽和単量体及び水を含有する単量体水溶液中でエチレン性不飽和単量体を重合して、重合体を含む含水ゲル状重合体を形成することと、含水ゲル状重合体を乾燥することとを含む方法によって、重合体粒子を得ることができる。塊状の含水ゲル状重合体が形成される場合、これを粗砕し、含水ゲル状重合体の粗砕物を乾燥してもよい。含水ゲル状重合体又はその粗砕物を、乾燥後、粉砕してもよく、粉砕により得られる粒子を分級してもよい。後述する表面架橋に供される重合体粒子は、乾燥した粗砕物であってもよいし、粗砕物を更に粉砕して得られる粒子であってもよい。粗砕物を粉砕して得られる重合体粒子を分級し、重合体粒子の粒度を必要に応じて調整してから表面架橋に供してもよい。
In the case of the aqueous solution polymerization method, for example, the ethylenically unsaturated monomer is polymerized in a monomer aqueous solution containing an ethylenically unsaturated monomer and water to form a hydrogel polymer containing the polymer. The polymer particles can be obtained by a method including the above and drying of the hydrogel polymer. When a lumpy hydrogel polymer is formed, it may be coarsely crushed and the crude product of the hydrogel polymer may be dried. The hydrogel polymer or a crude product thereof may be dried and then pulverized, or the particles obtained by pulverization may be classified. The polymer particles used for surface cross-linking, which will be described later, may be a dried coarsely crushed product or particles obtained by further pulverizing the coarsely crushed product. The polymer particles obtained by pulverizing the coarsely crushed product may be classified, the particle size of the polymer particles may be adjusted as necessary, and then subjected to surface cross-linking.
単量体水溶液におけるエチレン性不飽和単量体の濃度は、単量体水溶液の質量を基準として、20質量%以上飽和濃度以下、25~70質量%、又は30~50質量%であってもよい。
The concentration of the ethylenically unsaturated monomer in the aqueous monomer solution may be 20% by mass or more and less than the saturated concentration, 25 to 70% by mass, or 30 to 50% by mass based on the mass of the aqueous monomer solution. Good.
単量体水溶液は、重合開始剤を更に含有してもいてもよい。重合開始剤は、光重合開始剤又は熱ラジカル重合開始剤であってもよく、水溶性の熱ラジカル重合開始剤であってもよい。熱ラジカル重合性化合物が、アゾ化合物、過酸化物又はこれらの組み合わせであってもよい。重合開始剤の量は、エチレン性不飽和単量体1モルに対して0.00005~0.01モルであってもよい。
The monomer aqueous solution may further contain a polymerization initiator. The polymerization initiator may be a photopolymerization initiator or a thermal radical polymerization initiator, or may be a water-soluble thermal radical polymerization initiator. The thermally radically polymerizable compound may be an azo compound, a peroxide, or a combination thereof. The amount of the polymerization initiator may be 0.00005 to 0.01 mol per 1 mol of the ethylenically unsaturated monomer.
単量体水溶液が、上述の内部架橋剤を更に含有してもよい。内部架橋剤の量は、エチレン性不飽和単量体1モルに対して、0ミリモル以上、0.001ミリモル以上、0.01ミリモル以上、0.015ミリモル以上、又は0.020ミリモル以上であってもよく、2ミリモル以下、1ミリモル以下、0.5ミリモル以下、又は0.1ミリモル以下であってもよい。単量体水溶液は、必要に応じて、連鎖移動剤、増粘剤等のその他の添加剤を更に含有してもよい。
The monomer aqueous solution may further contain the above-mentioned internal cross-linking agent. The amount of the internal cross-linking agent is 0 mmol or more, 0.001 mmol or more, 0.01 mmol or more, 0.015 mmol or more, or 0.020 mmol or more with respect to 1 mol of the ethylenically unsaturated monomer. It may be 2 mmol or less, 1 mmol or less, 0.5 mmol or less, or 0.1 mmol or less. If necessary, the aqueous monomer solution may further contain other additives such as a chain transfer agent and a thickener.
重合温度は、使用する重合開始剤によって異なるが、例えば、0~130℃、10~110℃であってもよい。重合時間は、1~200分、又は5~100分であってもよい。
The polymerization temperature varies depending on the polymerization initiator used, but may be, for example, 0 to 130 ° C. or 10 to 110 ° C. The polymerization time may be 1 to 200 minutes or 5 to 100 minutes.
重合によって形成される含水ゲル状重合体の含水率(含水ゲル状重合体の質量を基準とする水の含有量)は、30~80質量%、40~75質量%、又は50~70質量%であってもよい。
The water content of the hydrogel polymer formed by polymerization (water content based on the mass of the hydrogel polymer) is 30 to 80% by mass, 40 to 75% by mass, or 50 to 70% by mass. May be.
塊状の含水ゲル状重合体を粗砕する場合、粗砕により得られる粗砕物は、粒子状であってよく、粒子が連なったような細長い形状であってもよい。粗砕物の最小幅は、例えば、0.1~15mm、又は1.0~10mm程度であってもよい。粗砕物の最大幅は、0.1~200mm、又は1.0~150mm程度であってもよい。粗砕のための装置の例としては、ニーダー(例えば、加圧式ニーダー、双腕型ニーダー等)、ミートチョッパー、カッターミル、ファーマミルが挙げられる。塊状の含水ゲル状重合体を、必要により粗砕前に裁断してもよい。
When a lumpy hydrogel polymer is coarsely crushed, the coarsely crushed product obtained by the coarse crushing may be in the form of particles or may have an elongated shape such that particles are connected. The minimum width of the pyroclastic material may be, for example, about 0.1 to 15 mm or 1.0 to 10 mm. The maximum width of the pyroclastic material may be about 0.1 to 200 mm or 1.0 to 150 mm. Examples of devices for crushing include kneaders (eg, pressurized kneaders, double-armed kneaders, etc.), meat choppers, cutter mills, and pharmacomills. If necessary, the lumpy hydrogel polymer may be cut before coarse crushing.
含水ゲル状重合体又はその粗砕物は、主に水を除去するために、乾燥される。乾燥の方法は、自然乾燥、加熱乾燥、減圧乾燥等の一般的な方法であってよい。乾燥後の含水ゲル状重合体又はその粗砕物を更に粉砕し、得られる粒子を必要により分級することによって、適度な粒径を有する重合体粒子を得ることができる。粉砕の方法は特に限定されず、例えば、ローラーミル(ロールミル)、スタンプミル、ジェットミル、高速回転粉砕機(ハンマーミル、ピンミル、ロータビータミル等)、又は容器駆動型ミル(回転ミル、振動ミル、遊星ミル等)を使用する方法が適用できる。分級の方法も特に限定されず、例えば、振動篩、ロータリシフタ、円筒撹拌篩、ブロワシフタ、又はロータップ式振とう器を使用する方法が適用できる。
The hydrogel polymer or its crude product is dried mainly to remove water. The drying method may be a general method such as natural drying, heat drying, and vacuum drying. By further pulverizing the dried hydrogel polymer or a crude product thereof and classifying the obtained particles as necessary, polymer particles having an appropriate particle size can be obtained. The crushing method is not particularly limited, and for example, a roller mill (roll mill), a stamp mill, a jet mill, a high-speed rotary crusher (hammer mill, pin mill, rotor beater mill, etc.), or a container-driven mill (rotary mill, vibration mill, etc.). , Planet mill, etc.) can be applied. The classification method is also not particularly limited, and for example, a method using a vibrating sieve, a rotary shifter, a cylindrical stirring sieve, a blower shifter, or a low-tap type shaker can be applied.
逆相懸濁重合法の場合、例えば、炭化水素分散媒と、炭化水素分散媒中に分散した、エチレン性不飽和単量体、ラジカル重合開始剤及び水等を含む単量体水溶液と、界面活性剤とを含有する懸濁液中で、エチレン性不飽和単量体を重合し、それによって重合体を含む粒子状の含水ゲル状重合体を形成することと、懸濁液から炭化水素分散媒及び水を除去することとを含む方法によって、重合体粒子を得ることができる。
In the case of the reverse phase suspension polymerization method, for example, an interface between a hydrocarbon dispersion medium and a monomer aqueous solution containing an ethylenically unsaturated monomer, a radical polymerization initiator, water, etc. dispersed in the hydrocarbon dispersion medium. In a suspension containing an activator, an ethylenically unsaturated monomer is polymerized to form a particulate hydrogel polymer containing the polymer, and hydrocarbon dispersion from the suspension. Polymer particles can be obtained by methods involving removing the medium and water.
炭化水素分散媒は、炭素数6~8の鎖状脂肪族炭化水素、及び、炭素数6~8の脂環式炭化水素からなる群より選ばれる少なくとも1種の化合物を含んでいてもよい。炭化水素分散媒としては、n-ヘキサン、n-ヘプタン、2-メチルヘキサン、3-メチルヘキサン、2,3-ジメチルペンタン、3-エチルペンタン、n-オクタン等の鎖状脂肪族炭化水素;シクロヘキサン、メチルシクロヘキサン、シクロペンタン、メチルシクロペンタン、trans-1,2-ジメチルシクロペンタン、cis-1,3-ジメチルシクロペンタン、trans-1,3-ジメチルシクロペンタン等の脂環式炭化水素;ベンゼン、トルエン、キシレン等の芳香族炭化水素などが挙げられる。炭化水素分散媒は、単独で用いられてもよく、2種以上を組み合わせて用いられてもよい。炭化水素分散媒の量は、単量体を含む単量体水溶液100質量部に対して、30~1000質量部、40~500質量部、又は50~300質量部であってもよい。
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. , Methylcyclohexane, cyclopentane, methylcyclopentane, trans-1,2-dimethylcyclopentane, cis-1,3-dimethylcyclopentane, trans-1,3-dimethylcyclopentane and other alicyclic hydrocarbons; benzene, Examples include aromatic hydrocarbons such as toluene and xylene. The hydrocarbon dispersion medium may be used alone or in combination of two or more. The amount of the hydrocarbon dispersion medium may be 30 to 1000 parts by mass, 40 to 500 parts by mass, or 50 to 300 parts by mass with respect to 100 parts by mass of the aqueous monomer solution containing the monomer.
熱ラジカル重合開始剤の例としては、過硫酸塩、過酸化物、及びアゾ化合物が挙げられる。ラジカル重合開始剤の量は、エチレン性不飽和単量体1モルに対して0.00005~0.01モルであってもよい。
Examples of thermal radical polymerization initiators include persulfates, peroxides, and azo compounds. The amount of the radical polymerization initiator may be 0.00005 to 0.01 mol per 1 mol of the ethylenically unsaturated monomer.
逆相懸濁重合のための懸濁液が、上述の内部架橋剤を更に含有してもよい。内部架橋剤は、通常、エチレン系不飽和単量体を含む単量体水溶液に添加される。内部架橋剤の量は、エチレン性不飽和単量体1モルに対して、0ミリモル以上、0.001ミリモル以上、0.01ミリモル以上、0.015ミリモル以上、又は0.020ミリモル以上であってもよく、2ミリモル以下、1ミリモル以下、0.5ミリモル以下、又は0.1ミリモル以下であってもよい。
The suspension for reverse phase suspension polymerization may further contain the above-mentioned internal cross-linking agent. The internal cross-linking agent is usually added to a monomer aqueous solution containing an ethylene-based unsaturated monomer. The amount of the internal cross-linking agent is 0 mmol or more, 0.001 mmol or more, 0.01 mmol or more, 0.015 mmol or more, or 0.020 mmol or more with respect to 1 mol of the ethylenically unsaturated monomer. It may be 2 mmol or less, 1 mmol or less, 0.5 mmol or less, or 0.1 mmol or less.
逆相懸濁重合のための懸濁液は、通常、界面活性剤を更に含有する。界面活性剤は、ノニオン系界面活性剤、アニオン系界面活性剤等であってよい。ノニオン系界面活性剤の例としては、ソルビタン脂肪酸エステル、(ポリ)グリセリン脂肪酸エステル(「(ポリ)」とは、「ポリ」の接頭語がある場合及びない場合の双方を意味するものとする。以下同じ。)、ショ糖脂肪酸エステル、ポリオキシエチレンソルビタン脂肪酸エステル、ポリオキシエチレングリセリン脂肪酸エステル、ソルビトール脂肪酸エステル、ポリオキシエチレンソルビトール脂肪酸エステル、ポリオキシエチレンアルキルエーテル、ポリオキシエチレンアルキルフェニルエーテル、ポリオキシエチレンヒマシ油、ポリオキシエチレン硬化ヒマシ油、アルキルアリルホルムアルデヒド縮合ポリオキシエチレンエーテル、ポリオキシエチレンポリオキシプロピレンブロックコポリマー、ポリオキシエチレンポリオキシプロピルアルキルエーテル、ポリエチレングリコール脂肪酸エステル等が挙げられる。アニオン系界面活性剤の例としては、脂肪酸塩、アルキルベンゼンスルホン酸塩、アルキルメチルタウリン酸塩、ポリオキシエチレンアルキルフェニルエーテル硫酸エステル塩、ポリオキシエチレンアルキルエーテルスルホン酸塩、ポリオキシエチレンアルキルエーテルのリン酸エステル、及びポリオキシエチレンアルキルアリルエーテルのリン酸エステル等が挙げられる。界面活性剤は、単独で用いられてもよく、2種以上を組み合わせて用いられてもよい。界面活性剤の量は、単量体水溶液100質量部に対して、0.05~10質量部、0.08~5質量部、又は0.1~3質量部であってもよい。
Suspensions for reverse phase suspension polymerization usually further contain a surfactant. The surfactant may be a nonionic surfactant, an anionic surfactant or the like. Examples of nonionic surfactants include sorbitan fatty acid ester and (poly) glycerin fatty acid ester (“(poly)” means both with and without the prefix “poly”. The same applies 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, polyoxy. Examples thereof include ethylene castor 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. Examples of anionic surfactants include fatty acid salts, alkylbenzene sulfonates, alkylmethyl taur phosphates, polyoxyethylene alkylphenyl ether sulfates, polyoxyethylene alkyl ether sulfonates, and phosphorus in polyoxyethylene alkyl ethers. Examples thereof include acid esters and phosphoric acid esters of polyoxyethylene alkyl allyl ethers. The surfactant 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 aqueous monomer solution.
逆相懸濁重合のための懸濁液は、高分子系分散剤を更に含有してもよい。高分子系分散剤の例としては、無水マレイン酸変性ポリエチレン、無水マレイン酸変性ポリプロピレン、無水マレイン酸変性エチレン・プロピレン共重合体、無水マレイン酸変性EPDM(エチレン・プロピレン・ジエン・ターポリマー)、無水マレイン酸変性ポリブタジエン、無水マレイン酸・エチレン共重合体、無水マレイン酸・プロピレン共重合体、無水マレイン酸・エチレン・プロピレン共重合体、無水マレイン酸・ブタジエン共重合体、ポリエチレン、ポリプロピレン、エチレン・プロピレン共重合体、酸化型ポリエチレン、酸化型ポリプロピレン、酸化型エチレン・プロピレン共重合体、エチレン・アクリル酸共重合体、エチルセルロース、エチルヒドロキシエチルセルロース等が挙げられる。高分子系分散剤は、単独で用いられてもよく、2種以上を組み合わせて用いられてもよい。高分子系分散剤の量は、単量体水溶液100質量部に対して、0.05~10質量部、0.08~5質量部、又は0.1~3質量部であってもよい。
The suspension for reverse phase suspension polymerization may further contain a polymer-based dispersant. Examples of polymer dispersants include maleic anhydride-modified polyethylene, maleic anhydride-modified polypropylene, maleic anhydride-modified ethylene / propylene copolymer, maleic anhydride-modified EPDM (ethylene / propylene / diene / terpolymer), and anhydrous. Maleic acid-modified polybutadiene, maleic anhydride / ethylene copolymer, maleic anhydride / propylene copolymer, maleic anhydride / ethylene / propylene copolymer, maleic anhydride / butadiene copolymer, polyethylene, polypropylene, ethylene / propylene Examples thereof include copolymers, oxidized polyethylene, oxidized polypropylene, oxidized ethylene / propylene copolymers, ethylene / acrylic acid copolymers, ethyl cellulose, ethyl hydroxyethyl cellulose and the like. The polymer-based dispersant may be used alone or in combination of two or more. 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 aqueous monomer solution.
逆相懸濁重合のための懸濁液は、必要により、連鎖移動剤、増粘剤等のその他の成分を含有してもよい。重合反応の温度は、使用するラジカル重合開始剤によって異なるが、例えば20~150℃、又は40~120℃であってもよい。反応時間は、通常、0.5~4時間である。逆相懸濁重合を、複数回に分けて行ってもよい。
The suspension for reverse phase suspension polymerization may contain other components such as a chain transfer agent and a thickener, if necessary. The temperature of the polymerization reaction varies depending on the radical polymerization initiator used, but may be, for example, 20 to 150 ° C. or 40 to 120 ° C. The reaction time is usually 0.5-4 hours. The reverse phase suspension polymerization may be carried out in a plurality of times.
重合を行った後、含水ゲル状重合体及び炭化水素分散媒を含む懸濁液から炭化水素分散媒及び水を除去することによって、重合体粒子を得ることができる。例えば、共沸蒸留、デカンテーション、濾過、減圧乾燥、又はこれらの組み合わせによって、炭化水素分散媒及び水を除去することができる。重合体粒子中に、水、炭化水素分散媒又はこれらの両方がある程度残存していてもよい。
After the polymerization, the polymer particles can be obtained by removing the hydrocarbon dispersion medium and water from the suspension containing the hydrogel polymer and the hydrocarbon dispersion medium. For example, azeotropic distillation, decantation, filtration, vacuum drying, or a combination thereof can remove the hydrocarbon dispersion medium and water. Water, hydrocarbon dispersion medium, or both may remain in the polymer particles to some extent.
吸水性樹脂粒子を製造する方法は、重合体粒子と水及び表面架橋剤を含有する表面架橋剤水溶液とを含む反応混合物を加熱することによって、重合体粒子を表面架橋する工程を更に備えていてよい。
The method for producing water-absorbent resin particles further includes a step of surface-crosslinking the polymer particles by heating a reaction mixture containing the polymer particles and an aqueous solution of a surface-crosslinking agent containing water and a surface-crosslinking agent. Good.
表面架橋剤水溶液は、水と、水に溶解した表面架橋剤とを含有する。表面架橋剤水溶液が、親水性の有機溶媒を更に含有していてもよい。有機溶媒は、例えば、2-プロパノール、エタノール、メタノール等のアルコールであってもよい。水及び有機溶媒の合計量に対する水の比率は、100質量%以下であり、50質量%以上、60質量%以上、70質量%以上、80質量%以上、又は90質量%以上であってもよい。
The surface cross-linking agent aqueous solution contains water and a surface cross-linking agent dissolved in water. The aqueous surface cross-linking agent solution may further contain a hydrophilic organic solvent. The organic solvent may be, for example, an alcohol such as 2-propanol, ethanol or methanol. The ratio of water to the total amount of water and the organic solvent is 100% by mass or less, and may be 50% by mass or more, 60% by mass or more, 70% by mass or more, 80% by mass or more, or 90% by mass or more. ..
重合体粒子と表面架橋剤水溶液とを混合し、形成される反応混合物を、必要により攪拌しながら加熱することによって、重合体粒子を表面架橋することができる。表面架橋のための加熱温度は、表面架橋が進行するように適宜調整すればよく、例えば70~300℃、100~270℃、120~250℃、150~220℃、又は170~200℃であってもよい。表面架橋の反応時間は、例えば1~200分、10~100分、20~80分、30~70分、40~60分、又は5~100分であってもよい。表面架橋の工程を2回以上実施してもよい。
The polymer particles can be surface-crosslinked by mixing the polymer particles and the aqueous surface cross-linking agent solution and heating the reaction mixture formed with stirring, if necessary. The heating temperature for surface cross-linking may be appropriately adjusted so that the surface cross-linking proceeds, for example, 70 to 300 ° C., 100 to 270 ° C., 120 to 250 ° C., 150 to 220 ° C., or 170 to 200 ° C. You may. The reaction time for surface cross-linking may be, for example, 1 to 200 minutes, 10 to 100 minutes, 20 to 80 minutes, 30 to 70 minutes, 40 to 60 minutes, or 5 to 100 minutes. The surface cross-linking step may be carried out twice or more.
表面架橋後の重合体粒子から、必要により水及び炭化水素分散媒が除去される。表面架橋後の重合体粒子を、乾燥、粉砕、分級又はこれらの組み合わせによって更に処理してもよい。
Water and hydrocarbon dispersion medium are removed from the polymer particles after surface cross-linking, if necessary. The polymer particles after surface cross-linking may be further treated by drying, grinding, classification or a combination thereof.
吸水性樹脂粒子を製造する方法は、表面架橋後に、上記液体漏れ抑制剤を配置させる工程を含んでいてよい。
The method for producing the water-absorbent resin particles may include a step of arranging the liquid leakage inhibitor after surface cross-linking.
<吸収体>
一実施形態に係る吸収体は、本実施形態に係る吸水性樹脂粒子を含有する。本実施形態に係る吸収体は、繊維状物を含有することが可能であり、例えば、吸水性樹脂粒子及び繊維状物を含む混合物である。吸収体の構成としては、例えば、吸水性樹脂粒子及び繊維状物が均一混合された構成であってよく、シート状又は層状に形成された繊維状物の間に吸水性樹脂粒子が挟まれた構成であってもよく、その他の構成であってもよい。 <Absorbent>
The absorber according to one embodiment contains the water-absorbent resin particles according to this embodiment. The absorber according to the present embodiment can contain a fibrous substance, for example, a mixture containing water-absorbent resin particles and the fibrous substance. The structure of the absorber may be, for example, a structure in which the water-absorbent resin particles and the fibrous material are uniformly mixed, and the water-absorbent resin particles are sandwiched between the fibrous material formed in a sheet or layer. It may be a configuration or another configuration.
一実施形態に係る吸収体は、本実施形態に係る吸水性樹脂粒子を含有する。本実施形態に係る吸収体は、繊維状物を含有することが可能であり、例えば、吸水性樹脂粒子及び繊維状物を含む混合物である。吸収体の構成としては、例えば、吸水性樹脂粒子及び繊維状物が均一混合された構成であってよく、シート状又は層状に形成された繊維状物の間に吸水性樹脂粒子が挟まれた構成であってもよく、その他の構成であってもよい。 <Absorbent>
The absorber according to one embodiment contains the water-absorbent resin particles according to this embodiment. The absorber according to the present embodiment can contain a fibrous substance, for example, a mixture containing water-absorbent resin particles and the fibrous substance. The structure of the absorber may be, for example, a structure in which the water-absorbent resin particles and the fibrous material are uniformly mixed, and the water-absorbent resin particles are sandwiched between the fibrous material formed in a sheet or layer. It may be a configuration or another configuration.
繊維状物としては、微粉砕された木材パルプ;コットン;コットンリンター;レーヨン;セルロースアセテート等のセルロース系繊維;ポリアミド、ポリエステル、ポリオレフィン等の合成繊維;これらの繊維の混合物などが挙げられる。繊維状物は、単独で用いられてもよく、2種以上を組み合わせて用いられてもよい。繊維状物としては、親水性繊維を用いることができる。
Examples of the fibrous material include finely pulverized wood pulp; cotton; cotton linter; rayon; cellulosic fibers such as cellulose acetate; synthetic fibers such as polyamide, polyester and polyolefin; and a mixture of these fibers. The fibrous material may be used alone or in combination of two or more. As the fibrous material, hydrophilic fibers can be used.
吸収体における吸水性樹脂粒子の質量割合は、吸水性樹脂粒子及び繊維状物の合計に対して、40質量%以上、45質量%以上、50質量%以上、55質量%以上、60質量%以上、65質量%以上、又は70質量%であってよい。また、吸収体における吸水性樹脂粒子の質量割合は、吸水性樹脂粒子及び繊維状物の合計に対して、100質量%以下、95質量%以下、90質量%以下、85質量%以下、又は80質量%であってよい。吸収体における吸水性樹脂粒子の質量割合は、吸水性樹脂粒子及び繊維状物の合計に対して、40~100質量%、50~95質量%又は60~90質量%であってよい。
The mass ratio of the water-absorbent resin particles in the absorber is 40% by mass or more, 45% by mass or more, 50% by mass or more, 55% by mass or more, and 60% by mass or more with respect to the total of the water-absorbent resin particles and the fibrous material. , 65% by mass or more, or 70% by mass. The mass ratio of the water-absorbent resin particles in the absorber is 100% by mass or less, 95% by mass or less, 90% by mass or less, 85% by mass or less, or 80 with respect to the total of the water-absorbent resin particles and the fibrous material. It may be% by mass. The mass ratio of the water-absorbent resin particles in the absorber may be 40 to 100% by mass, 50 to 95% by mass, or 60 to 90% by mass with respect to the total of the water-absorbent resin particles and the fibrous material.
吸収体の使用前及び使用中における形態保持性を高めるために、繊維状物に接着性バインダーを添加することによって繊維同士を接着させてもよい。接着性バインダーとしては、熱融着性合成繊維、ホットメルト接着剤、接着性エマルジョン等が挙げられる。接着性バインダーは、単独で用いられてもよく、2種以上を組み合わせて用いられてもよい。
In order to improve the morphological retention before and during use of the absorber, the fibers may be adhered to each other by adding an adhesive binder to the fibrous material. Examples of the adhesive binder include heat-sealing synthetic fibers, hot melt adhesives, and adhesive emulsions. The adhesive binder may be used alone or in combination of two or more.
熱融着性合成繊維としては、例えば、ポリエチレン、ポリプロピレン、エチレン-プロピレン共重合体等の全融型バインダー;ポリプロピレンとポリエチレンとのサイドバイサイドや芯鞘構造からなる非全融型バインダーなどが挙げられる。上述の非全融型バインダーにおいては、ポリエチレン部分のみ熱融着することができる。
Examples of the heat-bondable synthetic fiber include a total fusion type binder such as polyethylene, polypropylene, and an ethylene-propylene copolymer; a side-by-side of polypropylene and polyethylene, and a non-total fusion type binder having a core-sheath structure. In the above-mentioned non-total fusion type binder, only the polyethylene portion can be heat-sealed.
ホットメルト接着剤としては、例えば、エチレン-酢酸ビニルコポリマー、スチレン-イソプレン-スチレンブロックコポリマー、スチレン-ブタジエン-スチレンブロックコポリマー、スチレン-エチレン-ブチレン-スチレンブロックコポリマー、スチレン-エチレン-プロピレン-スチレンブロックコポリマー、アモルファスポリプロピレン等のベースポリマーと、粘着付与剤、可塑剤、酸化防止剤等との混合物が挙げられる。
Examples of the hot melt adhesive include ethylene-vinyl acetate copolymer, styrene-isoprene-styrene block copolymer, styrene-butadiene-styrene block copolymer, styrene-ethylene-butylene-styrene block copolymer, and styrene-ethylene-propylene-styrene block copolymer. , A mixture of a base polymer such as amorphous polypropylene and a tackifier, a plasticizer, an antioxidant and the like.
接着性エマルジョンとしては、例えば、メチルメタクリレート、スチレン、アクリロニトリル、2ーエチルヘキシルアクリレート、ブチルアクリレート、ブタジエン、エチレン、及び、酢酸ビニルからなる群より選ばれる少なくとも一種の単量体の重合物が挙げられる。
Examples of the adhesive emulsion include polymers of at least one monomer selected from the group consisting of methyl methacrylate, styrene, acrylonitrile, 2-ethylhexyl acrylate, butyl acrylate, butadiene, ethylene, and vinyl acetate.
本実施形態に係る吸収体は、消臭剤、抗菌剤、香料等を含有してもよい。
The absorber according to the present embodiment may contain a deodorant, an antibacterial agent, a fragrance and the like.
本実施形態に係る吸収体の形状は、特に限定されず、例えばシート状であってよい。吸収体の厚さ(例えば、シート状の吸収体の厚さ)は、例えば0.1~20mm、0.3~15mmであってよい。
The shape of the absorber according to the present embodiment is not particularly limited, and may be, for example, a sheet shape. The thickness of the absorber (for example, the thickness of the sheet-shaped absorber) may be, for example, 0.1 to 20 mm and 0.3 to 15 mm.
<吸収性物品>
本実施形態に係る吸収性物品は、本実施形態に係る吸収体を備える。本実施形態に係る吸収性物品は、吸収体を保形するコアラップ;吸液対象の液が浸入する側の最外部に配置される液体透過性シート;吸液対象の液が浸入する側とは反対側の最外部に配置される液体不透過性シート等が挙げられる。吸収性物品としては、おむつ(例えば紙おむつ)、トイレトレーニングパンツ、失禁パッド、衛生材料(生理用ナプキン、タンポン等)、汗取りパッド、ペットシート、簡易トイレ用部材、動物排泄物処理材などが挙げられる。 <Absorbable article>
The absorbent article according to the present embodiment includes an absorber according to the present embodiment. The absorbent article according to the present embodiment is a core wrap that retains the shape of the absorber; a liquid permeable sheet that is arranged on the outermost side of the side where the liquid to be absorbed enters; Examples thereof include a liquid permeable sheet arranged on the outermost side on the opposite side. Examples of absorbent articles include diapers (for example, paper diapers), toilet training pants, incontinence pads, sanitary materials (sanitary napkins, tampons, etc.), sweat pads, pet sheets, toilet members, animal excrement treatment materials, and the like. ..
本実施形態に係る吸収性物品は、本実施形態に係る吸収体を備える。本実施形態に係る吸収性物品は、吸収体を保形するコアラップ;吸液対象の液が浸入する側の最外部に配置される液体透過性シート;吸液対象の液が浸入する側とは反対側の最外部に配置される液体不透過性シート等が挙げられる。吸収性物品としては、おむつ(例えば紙おむつ)、トイレトレーニングパンツ、失禁パッド、衛生材料(生理用ナプキン、タンポン等)、汗取りパッド、ペットシート、簡易トイレ用部材、動物排泄物処理材などが挙げられる。 <Absorbable article>
The absorbent article according to the present embodiment includes an absorber according to the present embodiment. The absorbent article according to the present embodiment is a core wrap that retains the shape of the absorber; a liquid permeable sheet that is arranged on the outermost side of the side where the liquid to be absorbed enters; Examples thereof include a liquid permeable sheet arranged on the outermost side on the opposite side. Examples of absorbent articles include diapers (for example, paper diapers), toilet training pants, incontinence pads, sanitary materials (sanitary napkins, tampons, etc.), sweat pads, pet sheets, toilet members, animal excrement treatment materials, and the like. ..
図1は、吸収性物品の一例を示す断面図である。図1に示す吸収性物品100は、吸収体10と、コアラップ20a,20bと、液体透過性シート30と、液体不透過性シート40と、を備える。吸収性物品100において、液体不透過性シート40、コアラップ20b、吸収体10、コアラップ20a、及び、液体透過性シート30がこの順に積層している。図1において、部材間に間隙があるように図示されている部分があるが、当該間隙が存在することなく部材間が密着していてよい。
FIG. 1 is a cross-sectional view showing an example of an absorbent article. The absorbent article 100 shown in FIG. 1 includes an absorbent body 10, core wraps 20a and 20b, a liquid permeable sheet 30, and a liquid permeable sheet 40. In the absorbent article 100, the liquid permeable sheet 40, the core wrap 20b, the absorbent body 10, the core wrap 20a, and the liquid permeable sheet 30 are laminated in this order. In FIG. 1, there is a portion shown so that there is a gap between the members, but the members may be in close contact with each other without the gap.
吸収体10は、本実施形態に係る吸水性樹脂粒子10aと、繊維状物を含む繊維層10bと、を有する。吸水性樹脂粒子10aは、繊維層10b内に分散している。
The absorber 10 has a water-absorbent resin particle 10a according to the present embodiment and a fiber layer 10b containing a fibrous material. The water-absorbent resin particles 10a are dispersed in the fiber layer 10b.
コアラップ20aは、吸収体10に接した状態で吸収体10の一方面側(図1中、吸収体10の上側)に配置されている。コアラップ20bは、吸収体10に接した状態で吸収体10の他方面側(図1中、吸収体10の下側)に配置されている。吸収体10は、コアラップ20aとコアラップ20bとの間に配置されている。コアラップ20a,20bとしては、ティッシュ、不織布等が挙げられる。コアラップ20a及びコアラップ20bは、例えば、吸収体10と同等の大きさの主面を有している。
The core wrap 20a is arranged on one side of the absorber 10 (upper side of the absorber 10 in FIG. 1) in contact with the absorber 10. The core wrap 20b is arranged on the other side of the absorber 10 (lower side of the absorber 10 in FIG. 1) in contact with the absorber 10. The absorber 10 is arranged between the core wrap 20a and the core wrap 20b. Examples of the core wraps 20a and 20b include tissues, non-woven fabrics and the like. The core wrap 20a and the core wrap 20b have, for example, a main surface having the same size as the absorber 10.
液体透過性シート30は、吸収対象の液が浸入する側の最外部に配置されている。液体透過性シート30は、コアラップ20aに接した状態でコアラップ20a上に配置されている。液体透過性シート30としては、ポリエチレン、ポリプロピレン、ポリエステル、ポリアミド等の合成樹脂からなる不織布、多孔質シートなどが挙げられる。液体不透過性シート40は、吸収性物品100において液体透過性シート30とは反対側の最外部に配置されている。液体不透過性シート40は、コアラップ20bに接した状態でコアラップ20bの下側に配置されている。液体不透過性シート40としては、ポリエチレン、ポリプロピレン、ポリ塩化ビニル等の合成樹脂からなるシート、これらの合成樹脂と不織布との複合材料からなるシートなどが挙げられる。液体透過性シート30及び液体不透過性シート40は、例えば、吸収体10の主面よりも広い主面を有しており、液体透過性シート30及び液体不透過性シート40の外縁部は、吸収体10及びコアラップ20a,20bの周囲に延在している。
The liquid permeable sheet 30 is arranged on the outermost side on the side where the liquid to be absorbed enters. The liquid permeable sheet 30 is arranged on the core wrap 20a in contact with the core wrap 20a. Examples of the liquid permeable sheet 30 include non-woven fabrics made of synthetic resins such as polyethylene, polypropylene, polyester and polyamide, and porous sheets. The liquid permeable sheet 40 is arranged on the outermost side of the absorbent article 100 on the opposite side of the liquid permeable sheet 30. The liquid impermeable sheet 40 is arranged under the core wrap 20b in contact with the core wrap 20b. Examples of the liquid impermeable sheet 40 include a sheet made of a synthetic resin such as polyethylene, polypropylene, and polyvinyl chloride, and a sheet made of a composite material of these synthetic resins and a non-woven fabric. The liquid permeable sheet 30 and the liquid permeable sheet 40 have, for example, a main surface wider than the main surface of the absorber 10, and the outer edges of the liquid permeable sheet 30 and the liquid permeable sheet 40 are It extends around the absorber 10 and the core wraps 20a, 20b.
吸収体10、コアラップ20a,20b、液体透過性シート30、及び、液体不透過性シート40の大小関係は、特に限定されず、吸収性物品の用途等に応じて適宜調整される。また、コアラップ20a,20bを用いて吸収体10を保形する方法は、特に限定されず、図1に示すように複数のコアラップにより吸収体を包んでよく、1枚のコアラップにより吸収体を包んでもよい。
The magnitude relationship between the absorbent body 10, the core wraps 20a and 20b, the liquid permeable sheet 30, and the liquid permeable sheet 40 is not particularly limited, and is appropriately adjusted according to the use of the absorbent article and the like. Further, the method of retaining the shape of the absorber 10 using the core wraps 20a and 20b is not particularly limited, and as shown in FIG. 1, the absorber may be wrapped by a plurality of core wraps, and the absorber is wrapped by one core wrap. But it may be.
本実施形態によれば、本実施形態に係る吸収体又は吸収性物品を用いた吸液方法を提供することができる。本実施形態に係る吸液方法は、本実施形態に係る吸収体又は吸収性物品に吸液対象の液を接触させる工程を備える。
According to the present embodiment, it is possible to provide a liquid absorbing method using an absorber or an absorbent article according to the present embodiment. The liquid absorbing method according to the present embodiment includes a step of bringing the liquid to be absorbed into contact with the absorber or the absorbent article according to the present embodiment.
<吸収体の液体漏れを抑制する方法及び乾式シリカの使用(応用)>
本実施形態によれば、吸水性樹脂粒子を含有する吸収体の液体漏れを抑制することができる。本実施形態に係る吸水性樹脂粒子を含有する吸収体の液体漏れを抑制する方法は、吸水性樹脂粒子に液体漏れ抑制剤としての乾式シリカを含有させる工程を備える。乾式シリカを含有させる工程は、上述した重合体粒子と、乾式シリカとを混合することにより、乾式シリカを含有させる工程であってよい。 <Method of suppressing liquid leakage from absorber and use of dry silica (application)>
According to this embodiment, it is possible to suppress liquid leakage of the absorber containing the water-absorbent resin particles. The method for suppressing liquid leakage of an absorber containing water-absorbent resin particles according to the present embodiment includes a step of incorporating dry silica as a liquid leakage inhibitor into the water-absorbent resin particles. The step of containing the dry silica may be a step of containing the dry silica by mixing the polymer particles described above with the dry silica.
本実施形態によれば、吸水性樹脂粒子を含有する吸収体の液体漏れを抑制することができる。本実施形態に係る吸水性樹脂粒子を含有する吸収体の液体漏れを抑制する方法は、吸水性樹脂粒子に液体漏れ抑制剤としての乾式シリカを含有させる工程を備える。乾式シリカを含有させる工程は、上述した重合体粒子と、乾式シリカとを混合することにより、乾式シリカを含有させる工程であってよい。 <Method of suppressing liquid leakage from absorber and use of dry silica (application)>
According to this embodiment, it is possible to suppress liquid leakage of the absorber containing the water-absorbent resin particles. The method for suppressing liquid leakage of an absorber containing water-absorbent resin particles according to the present embodiment includes a step of incorporating dry silica as a liquid leakage inhibitor into the water-absorbent resin particles. The step of containing the dry silica may be a step of containing the dry silica by mixing the polymer particles described above with the dry silica.
本発明の一実施形態として、吸水性樹脂粒子を含有する吸収体の液体漏れを抑制するための乾式シリカの使用又は応用が提供される。本発明の他の実施形態として、吸水性樹脂粒子を含有する吸収体に用いられる、液体漏れ抑制剤の製造のための乾式シリカの使用又は応用が提供される。
As an embodiment of the present invention, the use or application of dry silica for suppressing liquid leakage of an absorber containing water-absorbent resin particles is provided. As another embodiment of the present invention, the use or application of dry silica for producing a liquid leakage inhibitor used for an absorber containing water-absorbent resin particles is provided.
以下、実施例を挙げて本発明についてさらに具体的に説明する。ただし、本発明はこれら実施例に限定されるものではない。
Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples.
<液体漏れ抑制剤としてのシリカの準備>
(乾式シリカA)
比表面積が200±5m2/g、嵩密度が33g/L、含水率が1.0%以下、一次平均粒子径が7~20nm、二次凝集体の平均粒子径が30~50μmである、乾式シリカ(キャボットジャパン株式会社、製品名:M-5)を準備した。これを乾式シリカAとした。 <Preparation of silica as a liquid leakage inhibitor>
(Dry silica A)
The specific surface area is 200 ± 5 m 2 / g, the bulk density is 33 g / L, the water content is 1.0% or less, the primary average particle size is 7 to 20 nm, and the average particle size of the secondary aggregate is 30 to 50 μm. Dry silica (Cabot Japan Co., Ltd., product name: M-5) was prepared. This was designated as dry silica A.
(乾式シリカA)
比表面積が200±5m2/g、嵩密度が33g/L、含水率が1.0%以下、一次平均粒子径が7~20nm、二次凝集体の平均粒子径が30~50μmである、乾式シリカ(キャボットジャパン株式会社、製品名:M-5)を準備した。これを乾式シリカAとした。 <Preparation of silica as a liquid leakage inhibitor>
(Dry silica A)
The specific surface area is 200 ± 5 m 2 / g, the bulk density is 33 g / L, the water content is 1.0% or less, the primary average particle size is 7 to 20 nm, and the average particle size of the secondary aggregate is 30 to 50 μm. Dry silica (Cabot Japan Co., Ltd., product name: M-5) was prepared. This was designated as dry silica A.
(乾式シリカB)
比表面積が300±5m2/g、嵩密度が40g/L、含水率が1.0%以下、一次平均粒子径が7~20nm、二次凝集体の平均粒子径が30~50μmである、乾式シリカ(キャボットジャパン株式会社、製品名:H300)を準備した。これを乾式シリカBとした。 (Dry silica B)
The specific surface area is 300 ± 5 m 2 / g, the bulk density is 40 g / L, the water content is 1.0% or less, the primary average particle size is 7 to 20 nm, and the average particle size of the secondary aggregate is 30 to 50 μm. Dry silica (Cabot Japan Co., Ltd., product name: H300) was prepared. This was designated as dry silica B.
比表面積が300±5m2/g、嵩密度が40g/L、含水率が1.0%以下、一次平均粒子径が7~20nm、二次凝集体の平均粒子径が30~50μmである、乾式シリカ(キャボットジャパン株式会社、製品名:H300)を準備した。これを乾式シリカBとした。 (Dry silica B)
The specific surface area is 300 ± 5 m 2 / g, the bulk density is 40 g / L, the water content is 1.0% or less, the primary average particle size is 7 to 20 nm, and the average particle size of the secondary aggregate is 30 to 50 μm. Dry silica (Cabot Japan Co., Ltd., product name: H300) was prepared. This was designated as dry silica B.
(乾式シリカC)
比表面積が200±5m2/g、嵩密度が54g/L、含水率が1.0%以下、一次平均粒子径が7~20nm、二次凝集体の平均粒子径が30~50μmである、乾式シリカ(キャボットジャパン株式会社、製品名:M3KD)を準備した。これを乾式シリカCとした。 (Dry silica C)
The specific surface area is 200 ± 5 m 2 / g, the bulk density is 54 g / L, the water content is 1.0% or less, the primary average particle size is 7 to 20 nm, and the average particle size of the secondary aggregate is 30 to 50 μm. Dry silica (Cabot Japan Co., Ltd., product name: M3KD) was prepared. This was designated as dry silica C.
比表面積が200±5m2/g、嵩密度が54g/L、含水率が1.0%以下、一次平均粒子径が7~20nm、二次凝集体の平均粒子径が30~50μmである、乾式シリカ(キャボットジャパン株式会社、製品名:M3KD)を準備した。これを乾式シリカCとした。 (Dry silica C)
The specific surface area is 200 ± 5 m 2 / g, the bulk density is 54 g / L, the water content is 1.0% or less, the primary average particle size is 7 to 20 nm, and the average particle size of the secondary aggregate is 30 to 50 μm. Dry silica (Cabot Japan Co., Ltd., product name: M3KD) was prepared. This was designated as dry silica C.
(乾式シリカD)
比表面積が200m2/g、嵩密度が31g/L、含水率が1.5%以下、一次平均粒子径が12nm、二次凝集体の平均粒子径が1~10μmである、乾式シリカ(日本アエロジル株式会社製、製品名:アエロジル200)を準備した。これを乾式シリカDとした。 (Dry silica D)
Dry silica (Japan) with a specific surface area of 200 m 2 / g, a bulk density of 31 g / L, a water content of 1.5% or less, a primary average particle size of 12 nm, and an average particle size of secondary aggregates of 1 to 10 μm. Aerosil Co., Ltd., product name: Aerosil 200) was prepared. This was designated as dry silica D.
比表面積が200m2/g、嵩密度が31g/L、含水率が1.5%以下、一次平均粒子径が12nm、二次凝集体の平均粒子径が1~10μmである、乾式シリカ(日本アエロジル株式会社製、製品名:アエロジル200)を準備した。これを乾式シリカDとした。 (Dry silica D)
Dry silica (Japan) with a specific surface area of 200 m 2 / g, a bulk density of 31 g / L, a water content of 1.5% or less, a primary average particle size of 12 nm, and an average particle size of secondary aggregates of 1 to 10 μm. Aerosil Co., Ltd., product name: Aerosil 200) was prepared. This was designated as dry silica D.
(乾式シリカE)
比表面積が216m2/g、嵩密度が41g/L、含水率が0.1%、一次平均粒子径が12nm、乾式シリカ(OCI Company,Ltd製、製品名:KONASIL K-200)を準備した。これを乾式シリカEとした。 (Dry silica E)
A dry silica (OCI Company, Ltd., product name: KONASIL K-200) having a specific surface area of 216 m 2 / g, a bulk density of 41 g / L, a water content of 0.1%, a primary average particle size of 12 nm, and a dry silica (manufactured by OCI Company, Ltd.) was prepared. .. This was designated as dry silica E.
比表面積が216m2/g、嵩密度が41g/L、含水率が0.1%、一次平均粒子径が12nm、乾式シリカ(OCI Company,Ltd製、製品名:KONASIL K-200)を準備した。これを乾式シリカEとした。 (Dry silica E)
A dry silica (OCI Company, Ltd., product name: KONASIL K-200) having a specific surface area of 216 m 2 / g, a bulk density of 41 g / L, a water content of 0.1%, a primary average particle size of 12 nm, and a dry silica (manufactured by OCI Company, Ltd.) was prepared. .. This was designated as dry silica E.
(乾式シリカF)
比表面積が155m2/g、嵩密度が47g/L、含水率が0.1%、一次平均粒子径が14nm、乾式シリカ(OCI Company,Ltd製、製品名:KONASIL K-150)を準備した。これを乾式シリカFとした。 (Dry silica F)
A dry silica (OCI Company, Ltd., product name: KONASIL K-150) having a specific surface area of 155 m 2 / g, a bulk density of 47 g / L, a water content of 0.1%, a primary average particle size of 14 nm, and a dry silica (manufactured by OCI Company, Ltd.) was prepared. .. This was designated as dry silica F.
比表面積が155m2/g、嵩密度が47g/L、含水率が0.1%、一次平均粒子径が14nm、乾式シリカ(OCI Company,Ltd製、製品名:KONASIL K-150)を準備した。これを乾式シリカFとした。 (Dry silica F)
A dry silica (OCI Company, Ltd., product name: KONASIL K-150) having a specific surface area of 155 m 2 / g, a bulk density of 47 g / L, a water content of 0.1%, a primary average particle size of 14 nm, and a dry silica (manufactured by OCI Company, Ltd.) was prepared. .. This was designated as dry silica F.
(乾式シリカG)
比表面積が200m2/g、嵩密度が35g/L、含水率が1.5%以下、一次平均粒子径が12nm、乾式シリカ(株式会社トクヤマ製、製品名:レオロシール QS-102)を準備した。これを乾式シリカGとした。 (Dry silica G)
A dry silica (manufactured by Tokuyama Corporation, product name: Leoloseal QS-102) having a specific surface area of 200 m 2 / g, a bulk density of 35 g / L, a water content of 1.5% or less, and a primary average particle diameter of 12 nm was prepared. .. This was designated as dry silica G.
比表面積が200m2/g、嵩密度が35g/L、含水率が1.5%以下、一次平均粒子径が12nm、乾式シリカ(株式会社トクヤマ製、製品名:レオロシール QS-102)を準備した。これを乾式シリカGとした。 (Dry silica G)
A dry silica (manufactured by Tokuyama Corporation, product name: Leoloseal QS-102) having a specific surface area of 200 m 2 / g, a bulk density of 35 g / L, a water content of 1.5% or less, and a primary average particle diameter of 12 nm was prepared. .. This was designated as dry silica G.
(湿式シリカ)
比表面積が190m2/g、嵩密度が100g/L、含水率が6.1%、一次平均粒子径が10~30nm、二次凝集体の平均粒子径が9.8μmである、湿式シリカ(OSC(Oriental Silicas Corporation)製、製品名:トクシールNPS)を準備した。 (Wet silica)
Wet silica (specific surface area 190 m 2 / g, bulk density 100 g / L, moisture content 6.1%, primary average particle size 10-30 nm, average particle size of secondary aggregates 9.8 μm) OSC (Oriental Silkas Corporation), product name: Toxile NPS) was prepared.
比表面積が190m2/g、嵩密度が100g/L、含水率が6.1%、一次平均粒子径が10~30nm、二次凝集体の平均粒子径が9.8μmである、湿式シリカ(OSC(Oriental Silicas Corporation)製、製品名:トクシールNPS)を準備した。 (Wet silica)
Wet silica (specific surface area 190 m 2 / g, bulk density 100 g / L, moisture content 6.1%, primary average particle size 10-30 nm, average particle size of secondary aggregates 9.8 μm) OSC (Oriental Silkas Corporation), product name: Toxile NPS) was prepared.
比表面積は、BET比表面積(N2)法によって測定された値であり、含水率は、顔料及び体質顔料一般試験方法ISO787-2によって測定された値であり、一次平均粒子は、透過型電子顕微鏡による観察によって測定された値であり、二次凝集体の平均粒子径は、レーザー回折・散乱法によって測定された値である。
The specific surface area is a value measured by the BET specific surface area (N 2 ) method, the water content is a value measured by the general test method ISO787-2 for pigments and extender pigments, and the primary average particles are transmitted electrons. It is a value measured by observation with a microscope, and the average particle size of the secondary aggregate is a value measured by a laser diffraction / scattering method.
液体漏れ抑制剤としてのシリカの嵩密度は、粉体特性評価装置(ホソカワミクロン株式会社製、型番:PT-X)を用いて下記手順で測定した。嵩密度の測定は室温(25℃±2℃)の条件で行った。
The bulk density of silica as a liquid leakage inhibitor was measured by the following procedure using a powder property evaluation device (manufactured by Hosokawa Micron Co., Ltd., model number: PT-X). The bulk density was measured at room temperature (25 ° C ± 2 ° C).
まず、空容器(カップXS-18、内径5.0cm、高さ5.0cm、容積100cm3)の質量W0を測定した。次に、装置付属のスコップXS-12を用いて約120mLのシリカを上記容器に投入した。投入後、ブレードXS-13を用いて、容器の上部からはみ出したシリカをすりきって除去した。続いて、シリカを含む容器の質量W1を測定した。質量W0及び質量W1に基づき、下記式より嵩密度を求めた。嵩密度を計3回測定し、その平均値をシリカの嵩密度として得た。
シリカの嵩密度[g/L]=(W1[g]-W0[g])/100[cm3]×1000 First, the mass W 0 of an empty container (cup XS-18, inner diameter 5.0 cm, height 5.0 cm,volume 100 cm 3 ) was measured. Next, about 120 mL of silica was put into the container using the scoop XS-12 attached to the device. After charging, the blade XS-13 was used to scrape off the silica protruding from the upper part of the container. Subsequently, the mass was measured W 1 of the vessel containing the silica. Based on the mass W 0 and the mass W 1 , the bulk density was calculated from the following formula. The bulk density was measured three times in total, and the average value was obtained as the bulk density of silica.
Bulk density of silica [g / L] = (W 1 [g] -W 0 [g]) / 100 [cm 3 ] x 1000
シリカの嵩密度[g/L]=(W1[g]-W0[g])/100[cm3]×1000 First, the mass W 0 of an empty container (cup XS-18, inner diameter 5.0 cm, height 5.0 cm,
Bulk density of silica [g / L] = (W 1 [g] -W 0 [g]) / 100 [cm 3 ] x 1000
<重合体粒子の作製>
製造例1
第1段目の重合反応
還流冷却器、滴下ロート、窒素ガス導入管、並びに、攪拌機として、翼径5cmの4枚傾斜パドル翼を2段で有する攪拌翼を備えた内径11cm、内容積2Lの丸底円筒型セパラブルフラスコを準備した。このフラスコに、n-ヘプタン293g、及び、高分子系分散剤としての無水マレイン酸変性エチレン・プロピレン共重合体(三井化学株式会社、ハイワックス1105A)0.736gを入れた。フラスコ内の反応液を攪拌しつつ80℃まで昇温して、高分子系分散剤をn-ヘプタンに溶解させた。その後、反応液を50℃まで冷却した。 <Preparation of polymer particles>
Manufacturing example 1
First-stage polymerization reaction A reflux cooler, 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, with an inner diameter of 11 cm and an internal volume of 2 L. A round-bottomed cylindrical separable flask was prepared. In this flask, 293 g of n-heptane and 0.736 g of a maleic anhydride-modified ethylene-propylene copolymer (Mitsui Chemicals, Inc., High Wax 1105A) as a polymer-based dispersant were placed. The reaction solution in the flask was heated to 80 ° C. with stirring to dissolve the polymer-based dispersant in n-heptane. Then, the reaction solution was cooled to 50 ° C.
製造例1
第1段目の重合反応
還流冷却器、滴下ロート、窒素ガス導入管、並びに、攪拌機として、翼径5cmの4枚傾斜パドル翼を2段で有する攪拌翼を備えた内径11cm、内容積2Lの丸底円筒型セパラブルフラスコを準備した。このフラスコに、n-ヘプタン293g、及び、高分子系分散剤としての無水マレイン酸変性エチレン・プロピレン共重合体(三井化学株式会社、ハイワックス1105A)0.736gを入れた。フラスコ内の反応液を攪拌しつつ80℃まで昇温して、高分子系分散剤をn-ヘプタンに溶解させた。その後、反応液を50℃まで冷却した。 <Preparation of polymer particles>
Manufacturing example 1
First-stage polymerization reaction A reflux cooler, 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, with an inner diameter of 11 cm and an internal volume of 2 L. A round-bottomed cylindrical separable flask was prepared. In this flask, 293 g of n-heptane and 0.736 g of a maleic anhydride-modified ethylene-propylene copolymer (Mitsui Chemicals, Inc., High Wax 1105A) as a polymer-based dispersant were placed. The reaction solution in the flask was heated to 80 ° C. with stirring to dissolve the polymer-based dispersant in n-heptane. Then, the reaction solution was cooled to 50 ° C.
内容積300mLのビーカーに、濃度80.5質量%のアクリル酸水溶液92.0g(1.03モル)を入れた。ビーカーを外部から冷却しつつ、アクリル酸水溶液に対して濃度20.9質量%の水酸化ナトリウム水溶液147.7gを滴下し、それにより75モル%のアクリル酸を中和した。次いで、アクリル酸水溶液に、増粘剤としてヒドロキシルエチルセルロース0.092g(住友精化株式会社、HECAW-15F)、水溶性ラジカル重合開始剤として2,2’-アゾビス(2-アミジノプロパン)2塩酸塩0.092g(0.339ミリモル)及び過硫酸カリウム0.018g(0.067ミリモル)、内部架橋剤としてエチレングリコールジグリシジルエーテル0.010g(0.057ミリモル)を溶解させて、第1段目の単量体水溶液を調製した。
92.0 g (1.03 mol) of an acrylic acid aqueous solution having a concentration of 80.5 mass% was placed in a beaker having an internal volume of 300 mL. While cooling the beaker from the outside, 147.7 g of a sodium hydroxide aqueous solution having a concentration of 20.9 mass% was added dropwise to the acrylic acid aqueous solution, thereby neutralizing 75 mol% of acrylic acid. Next, 0.092 g of hydroxylethyl cellulose (Sumitomo Seika Co., Ltd., HECAW-15F) as a thickener and 2,2'-azobis (2-amidinopropane) dihydrochloride as a water-soluble radical polymerization initiator were added to an aqueous acrylic acid solution. The first step is to dissolve 0.092 g (0.339 mmol), 0.018 g (0.067 mmol) of potassium persulfate, and 0.010 g (0.057 mmol) of ethylene glycol diglycidyl ether as an internal cross-linking agent. A monomer aqueous solution of the above was prepared.
第1段目の単量体水溶液を、セパラブルフラスコ内の上述の反応液に添加し、反応液を10分間攪拌した。次いで、n-ヘプタン6.62g及びショ糖ステアリン酸エステル(HLB:3、三菱化学フーズ株式会社、リョートーシュガーエステルS-370)0.736gを含む界面活性剤溶液を反応液に添加し、撹拌翼の回転数を550rpmとして反応液を攪拌しながら、系内を窒素で十分に置換した。その後、セパラブルフラスコを70℃の水浴中で加熱しながら、60分間かけて重合反応を進行させた。この重合反応により、含水ゲル状重合体を含む第1段目の重合スラリー液を得た。
The first-stage monomer aqueous solution was added to the above-mentioned reaction solution in the separable flask, and the reaction solution was stirred for 10 minutes. Next, a surfactant solution containing 6.62 g of n-heptane and 0.736 g of sucrose stearic acid ester (HLB: 3, Mitsubishi Chemical Foods Co., Ltd., Ryoto Sugar Ester S-370) was added to the reaction solution, and the mixture was stirred. The inside of the system was sufficiently replaced with nitrogen while stirring the reaction solution at a blade rotation speed of 550 rpm. Then, the polymerization reaction was allowed to proceed over 60 minutes while heating the separable flask in a water bath at 70 ° C. By this polymerization reaction, a first-stage polymerization slurry liquid containing a hydrogel-like polymer was obtained.
第2段目の重合反応
内容積500mLのビーカーに、濃度80.5質量%のアクリル酸水溶液128.8g(1.44モル)を入れた。ビーカーを外部より冷却しつつ、アクリル酸水溶液に対して濃度27質量%の水酸化ナトリウム水溶液159.0gを滴下し、それにより75モル%のアクリル酸を中和した。次いで、アクリル酸水溶液に、2,2’-アゾビス(2-アミジノプロパン)2塩酸塩0.129g(0.476ミリモル)、及び過硫酸カリウム0.026g(0.096ミリモル)を溶解させて、第2段目の単量体水溶液を調製した。 Second-stage polymerization reaction 128.8 g (1.44 mol) of an acrylic acid aqueous solution having a concentration of 80.5% by mass was placed in a beaker having an internal volume of 500 mL. While cooling the beaker from the outside, 159.0 g of a sodium hydroxide aqueous solution having a concentration of 27% by mass was added dropwise to the acrylic acid aqueous solution, thereby neutralizing 75 mol% of acrylic acid. Next, 0.129 g (0.476 mmol) of 2,2'-azobis (2-amidinopropane) dihydrochloride and 0.026 g (0.096 mmol) of potassium persulfate were dissolved in an aqueous acrylic acid solution. A second-stage monomer aqueous solution was prepared.
内容積500mLのビーカーに、濃度80.5質量%のアクリル酸水溶液128.8g(1.44モル)を入れた。ビーカーを外部より冷却しつつ、アクリル酸水溶液に対して濃度27質量%の水酸化ナトリウム水溶液159.0gを滴下し、それにより75モル%のアクリル酸を中和した。次いで、アクリル酸水溶液に、2,2’-アゾビス(2-アミジノプロパン)2塩酸塩0.129g(0.476ミリモル)、及び過硫酸カリウム0.026g(0.096ミリモル)を溶解させて、第2段目の単量体水溶液を調製した。 Second-stage polymerization reaction 128.8 g (1.44 mol) of an acrylic acid aqueous solution having a concentration of 80.5% by mass was placed in a beaker having an internal volume of 500 mL. While cooling the beaker from the outside, 159.0 g of a sodium hydroxide aqueous solution having a concentration of 27% by mass was added dropwise to the acrylic acid aqueous solution, thereby neutralizing 75 mol% of acrylic acid. Next, 0.129 g (0.476 mmol) of 2,2'-azobis (2-amidinopropane) dihydrochloride and 0.026 g (0.096 mmol) of potassium persulfate were dissolved in an aqueous acrylic acid solution. A second-stage monomer aqueous solution was prepared.
セパラブルフラスコ内の第1段目の重合スラリー液を、撹拌翼の回転数を1000rpmとして撹拌しながら25℃に冷却した。そこに、第2段目の単量体水溶液の全量を添加し、続いて系内を窒素で30分間かけて置換した。その後、セパラブルフラスコを70℃の水浴中で加熱しながら、60分間かけて重合反応を進行させた。重合後架橋のための架橋剤として2質量%のエチレングリコールジグリシジルエーテル水溶液0.580g(0.067ミリモル)を添加し、含水ゲル状重合体を得た。
The first-stage polymerized slurry liquid in the separable flask was cooled to 25 ° C. while stirring at a stirring blade rotation speed of 1000 rpm. The whole amount of the aqueous monomer solution of the second stage was added thereto, and then the inside of the system was replaced with nitrogen over 30 minutes. Then, the polymerization reaction was allowed to proceed over 60 minutes while heating the separable flask in a water bath at 70 ° C. As a cross-linking agent for post-polymerization cross-linking, 0.580 g (0.067 mmol) of a 2% by mass ethylene glycol diglycidyl ether aqueous solution was added to obtain a hydrogel polymer.
含水ゲル状重合体を含む反応液に、濃度45質量%のジエチレントリアミン5酢酸5ナトリウム水溶液0.265gを攪拌下で添加した。その後、125℃に設定した油浴にフラスコを浸漬し、n-ヘプタンと水との共沸蒸留により、239.0gの水を系外へ抜き出した。その後、反応液に表面架橋剤として濃度2質量%のエチレングリコールジグリシジルエーテル水溶液4.42g(0.507ミリモル)を添加し、83℃で2時間かけて、表面架橋剤による架橋反応を進行させた。
0.265 g of a diethylenetriamine-5 sodium acetate aqueous solution having a concentration of 45% by mass was added to the reaction solution containing the hydrogel polymer under stirring. Then, the flask was immersed in an oil bath set at 125 ° C., and 239.0 g of water was extracted from the system by azeotropic distillation of n-heptane and water. Then, 4.42 g (0.507 mmol) of an ethylene glycol diglycidyl ether aqueous solution having a concentration of 2% by mass was added to the reaction solution as a surface cross-linking agent, and the cross-linking reaction with the surface cross-linking agent was allowed to proceed at 83 ° C. for 2 hours. It was.
表面架橋反応後の反応液から、125℃での加熱によりn-ヘプタンと水とを留去して、反応生成物を得た。得られた反応生成物を目開き850μmの篩に通過させ、228.3gの重合体粒子を得た。該重合体粒子の中位粒子径は364μmであった。必要により、同様の方法で複数回重合を実施した。
From the reaction solution after the surface cross-linking reaction, n-heptane and water were distilled off by heating at 125 ° C. to obtain a reaction product. The obtained reaction product was passed through a sieve having an opening of 850 μm to obtain 228.3 g of polymer particles. The medium particle size of the polymer particles was 364 μm. If necessary, polymerization was carried out multiple times in the same manner.
製造例2
第1段目の重合反応における水溶性ラジカル重合開始剤を2,2’-アゾビス(2-アミジノプロパン)2塩酸塩を用いずに、過硫酸カリウム0.0736g(0.272ミリモル)に変更し、第2段目の重合反応における水溶性ラジカル重合開始剤を2,2’-アゾビス(2-アミジノプロパン)2塩酸塩を用いずに、過硫酸カリウム0.090g(0.333ミリモル)に変更したこと、内部架橋剤としてエチレングリコールジグリシジルエーテル0.0116g(0.067ミリモル)を用いたこと、重合後架橋のための架橋剤を添加しなかったこと、第2段目の重合後の含水ゲル状重合体において、共沸蒸留により256.1gの水を系外へ抜き出したこと以外は、製造例1と同様にして、重合体粒子230.6gを得た。該重合体粒子の中位粒子径は349μmであった。 Manufacturing example 2
The water-soluble radical polymerization initiator in the first-stage polymerization reaction was changed to 0.0736 g (0.272 mmol) of potassium persulfate without using 2,2'-azobis (2-amidinopropane) dihydrochloride. , The water-soluble radical polymerization initiator in the second-stage polymerization reaction was changed to 0.090 g (0.333 mmol) of potassium persulfate without using 2,2'-azobis (2-amidinopropane) dihydrochloride. As a result, 0.0116 g (0.067 mmol) of ethylene glycol diglycidyl ether was used as the internal cross-linking agent, no cross-linking agent was added for post-polymerization cross-linking, and water content after the second stage polymerization. In the gel-like polymer, 230.6 g of polymer particles were obtained in the same manner as in Production Example 1 except that 256.1 g of water was extracted from the system by co-boiling distillation. The medium particle size of the polymer particles was 349 μm.
第1段目の重合反応における水溶性ラジカル重合開始剤を2,2’-アゾビス(2-アミジノプロパン)2塩酸塩を用いずに、過硫酸カリウム0.0736g(0.272ミリモル)に変更し、第2段目の重合反応における水溶性ラジカル重合開始剤を2,2’-アゾビス(2-アミジノプロパン)2塩酸塩を用いずに、過硫酸カリウム0.090g(0.333ミリモル)に変更したこと、内部架橋剤としてエチレングリコールジグリシジルエーテル0.0116g(0.067ミリモル)を用いたこと、重合後架橋のための架橋剤を添加しなかったこと、第2段目の重合後の含水ゲル状重合体において、共沸蒸留により256.1gの水を系外へ抜き出したこと以外は、製造例1と同様にして、重合体粒子230.6gを得た。該重合体粒子の中位粒子径は349μmであった。 Manufacturing example 2
The water-soluble radical polymerization initiator in the first-stage polymerization reaction was changed to 0.0736 g (0.272 mmol) of potassium persulfate without using 2,2'-azobis (2-amidinopropane) dihydrochloride. , The water-soluble radical polymerization initiator in the second-stage polymerization reaction was changed to 0.090 g (0.333 mmol) of potassium persulfate without using 2,2'-azobis (2-amidinopropane) dihydrochloride. As a result, 0.0116 g (0.067 mmol) of ethylene glycol diglycidyl ether was used as the internal cross-linking agent, no cross-linking agent was added for post-polymerization cross-linking, and water content after the second stage polymerization. In the gel-like polymer, 230.6 g of polymer particles were obtained in the same manner as in Production Example 1 except that 256.1 g of water was extracted from the system by co-boiling distillation. The medium particle size of the polymer particles was 349 μm.
製造例3
第1段目の重合反応における内部架橋剤としてのエチレングリコールジグリシジルエーテルの量を0.0046g(0.026ミリモル)に変更し、第2段目の水性液の調製において、内部架橋剤としてエチレングリコールジグリシジルエーテル0.0116g(0.067ミリモル)を用いたこと、重合後架橋のための架橋剤を添加しなかったこと、第2段目の重合後の含水ゲル状重合体において、共沸蒸留により219.2gの水を系外へ抜き出したこと、表面架橋剤としての濃度2質量%のエチレングリコールジグリシジルエーテル水溶液の量を6.62g(0.760ミリモル)に変更したこと以外は製造例1と同様の手順で、重合体粒子226.1gを得た。該重合体粒子の中位粒子径は356μmであった。 Manufacturing example 3
The amount of ethylene glycol diglycidyl ether as an internal cross-linking agent in the first-stage polymerization reaction was changed to 0.0046 g (0.026 mmol), and ethylene was used as an internal cross-linking agent in the preparation of the second-stage aqueous solution. 0.0116 g (0.067 mmol) of glycol diglycidyl ether was used, no cross-linking agent was added for post-polymerization cross-linking, and co-boiling was performed in the second-stage post-polymerization hydrogel polymer. Manufactured except that 219.2 g of water was extracted from the system by distillation and the amount of ethylene glycol diglycidyl ether aqueous solution having a concentration of 2% by mass as a surface cross-linking agent was changed to 6.62 g (0.760 mmol). 226.1 g of polymer particles were obtained in the same procedure as in Example 1. The medium particle size of the polymer particles was 356 μm.
第1段目の重合反応における内部架橋剤としてのエチレングリコールジグリシジルエーテルの量を0.0046g(0.026ミリモル)に変更し、第2段目の水性液の調製において、内部架橋剤としてエチレングリコールジグリシジルエーテル0.0116g(0.067ミリモル)を用いたこと、重合後架橋のための架橋剤を添加しなかったこと、第2段目の重合後の含水ゲル状重合体において、共沸蒸留により219.2gの水を系外へ抜き出したこと、表面架橋剤としての濃度2質量%のエチレングリコールジグリシジルエーテル水溶液の量を6.62g(0.760ミリモル)に変更したこと以外は製造例1と同様の手順で、重合体粒子226.1gを得た。該重合体粒子の中位粒子径は356μmであった。 Manufacturing example 3
The amount of ethylene glycol diglycidyl ether as an internal cross-linking agent in the first-stage polymerization reaction was changed to 0.0046 g (0.026 mmol), and ethylene was used as an internal cross-linking agent in the preparation of the second-stage aqueous solution. 0.0116 g (0.067 mmol) of glycol diglycidyl ether was used, no cross-linking agent was added for post-polymerization cross-linking, and co-boiling was performed in the second-stage post-polymerization hydrogel polymer. Manufactured except that 219.2 g of water was extracted from the system by distillation and the amount of ethylene glycol diglycidyl ether aqueous solution having a concentration of 2% by mass as a surface cross-linking agent was changed to 6.62 g (0.760 mmol). 226.1 g of polymer particles were obtained in the same procedure as in Example 1. The medium particle size of the polymer particles was 356 μm.
製造例4
第1段目の重合反応における内部架橋剤としてのエチレングリコールジグリシジルエーテルの量を0.0046g(0.026ミリモル)に変更したこと、第2段目の水性液の調製において、内部架橋剤としてエチレングリコールジグリシジルエーテル0.0116g(0.067ミリモル)を用いたこと、重合後架橋のための架橋剤を添加しなかったこと、第2段目の重合後の含水ゲル状重合体において、共沸蒸留により234.2gの水を系外へ抜き出したこと以外は製造例1と同様の手順で、重合体粒子220.2gを得た。該重合体粒子の中位粒子径は355μmであった。
製造例5
第1段目の重合反応における内部架橋剤としてのエチレングリコールジグリシジルエーテルの量を0.0368g(0.211ミリモル)に変更したこと第2段目の水性液の調製において、内部架橋剤としてエチレングリコールジグリシジルエーテル0.0515g(0.296ミリモル)を用いたこと、重合後架橋のための架橋剤を添加しなかったこと、第2段目の重合後の含水ゲル状重合体において、共沸蒸留により286.9gの水を系外へ抜き出したこと以外は製造例1と同様の手順で、重合体粒子221.8gを得た。該重合体粒子の中位粒子径は396μmであった。 Manufacturing example 4
The amount of ethylene glycol diglycidyl ether as an internal cross-linking agent in the first-stage polymerization reaction was changed to 0.0046 g (0.026 mmol), and as an internal cross-linking agent in the preparation of the second-stage aqueous solution. 0.0116 g (0.067 mmol) of ethylene glycol diglycidyl ether was used, no cross-linking agent was added for post-polymerization cross-linking, and both were used in the second-stage post-polymerization hydrogel polymer. 220.2 g of polymer particles were obtained in the same procedure as in Production Example 1 except that 234.2 g of water was extracted from the system by boiling distillation. The medium particle size of the polymer particles was 355 μm.
Production example 5
The amount of ethylene glycol diglycidyl ether as an internal cross-linking agent in the first-stage polymerization reaction was changed to 0.0368 g (0.211 mmol). In the preparation of the second-stage aqueous solution, ethylene was used as an internal cross-linking agent. The use of 0.0515 g (0.296 mmol) of glycol diglycidyl ether, no addition of a cross-linking agent for post-polymerization cross-linking, and co-boiling in the water-containing gel-like polymer after the second stage polymerization. 221.8 g of polymer particles were obtained in the same procedure as in Production Example 1 except that 286.9 g of water was extracted from the system by distillation. The medium particle size of the polymer particles was 396 μm.
第1段目の重合反応における内部架橋剤としてのエチレングリコールジグリシジルエーテルの量を0.0046g(0.026ミリモル)に変更したこと、第2段目の水性液の調製において、内部架橋剤としてエチレングリコールジグリシジルエーテル0.0116g(0.067ミリモル)を用いたこと、重合後架橋のための架橋剤を添加しなかったこと、第2段目の重合後の含水ゲル状重合体において、共沸蒸留により234.2gの水を系外へ抜き出したこと以外は製造例1と同様の手順で、重合体粒子220.2gを得た。該重合体粒子の中位粒子径は355μmであった。
製造例5
第1段目の重合反応における内部架橋剤としてのエチレングリコールジグリシジルエーテルの量を0.0368g(0.211ミリモル)に変更したこと第2段目の水性液の調製において、内部架橋剤としてエチレングリコールジグリシジルエーテル0.0515g(0.296ミリモル)を用いたこと、重合後架橋のための架橋剤を添加しなかったこと、第2段目の重合後の含水ゲル状重合体において、共沸蒸留により286.9gの水を系外へ抜き出したこと以外は製造例1と同様の手順で、重合体粒子221.8gを得た。該重合体粒子の中位粒子径は396μmであった。 Manufacturing example 4
The amount of ethylene glycol diglycidyl ether as an internal cross-linking agent in the first-stage polymerization reaction was changed to 0.0046 g (0.026 mmol), and as an internal cross-linking agent in the preparation of the second-stage aqueous solution. 0.0116 g (0.067 mmol) of ethylene glycol diglycidyl ether was used, no cross-linking agent was added for post-polymerization cross-linking, and both were used in the second-stage post-polymerization hydrogel polymer. 220.2 g of polymer particles were obtained in the same procedure as in Production Example 1 except that 234.2 g of water was extracted from the system by boiling distillation. The medium particle size of the polymer particles was 355 μm.
Production example 5
The amount of ethylene glycol diglycidyl ether as an internal cross-linking agent in the first-stage polymerization reaction was changed to 0.0368 g (0.211 mmol). In the preparation of the second-stage aqueous solution, ethylene was used as an internal cross-linking agent. The use of 0.0515 g (0.296 mmol) of glycol diglycidyl ether, no addition of a cross-linking agent for post-polymerization cross-linking, and co-boiling in the water-containing gel-like polymer after the second stage polymerization. 221.8 g of polymer particles were obtained in the same procedure as in Production Example 1 except that 286.9 g of water was extracted from the system by distillation. The medium particle size of the polymer particles was 396 μm.
製造例6
第2段目の重合後の含水ゲル状重合体において、共沸蒸留により228.7gの水を系外へ抜き出したこと以外は、製造例1と同様にして、重合体粒子227.7gを得た。該重合体粒子の中位粒子径は380μmであった。 Production example 6
In the hydrogel polymer after the second stage polymerization, 227.7 g of polymer particles were obtained in the same manner as in Production Example 1 except that 228.7 g of water was extracted from the system by azeotropic distillation. It was. The medium particle size of the polymer particles was 380 μm.
第2段目の重合後の含水ゲル状重合体において、共沸蒸留により228.7gの水を系外へ抜き出したこと以外は、製造例1と同様にして、重合体粒子227.7gを得た。該重合体粒子の中位粒子径は380μmであった。 Production example 6
In the hydrogel polymer after the second stage polymerization, 227.7 g of polymer particles were obtained in the same manner as in Production Example 1 except that 228.7 g of water was extracted from the system by azeotropic distillation. It was. The medium particle size of the polymer particles was 380 μm.
製造例7
第2段目の重合後の含水ゲル状重合体において、共沸蒸留により253.3gの水を系外へ抜き出したこと以外は、製造例1と同様にして、重合体粒子221.7gを得た。該重合体粒子の中位粒子径は356μmであった。 Production example 7
In the hydrogel polymer after the second stage polymerization, 221.7 g of polymer particles were obtained in the same manner as in Production Example 1 except that 253.3 g of water was extracted from the system by azeotropic distillation. It was. The medium particle size of the polymer particles was 356 μm.
第2段目の重合後の含水ゲル状重合体において、共沸蒸留により253.3gの水を系外へ抜き出したこと以外は、製造例1と同様にして、重合体粒子221.7gを得た。該重合体粒子の中位粒子径は356μmであった。 Production example 7
In the hydrogel polymer after the second stage polymerization, 221.7 g of polymer particles were obtained in the same manner as in Production Example 1 except that 253.3 g of water was extracted from the system by azeotropic distillation. It was. The medium particle size of the polymer particles was 356 μm.
製造例8
第2段目の重合後の含水ゲル状重合体において、共沸蒸留により261.5gの水を系外へ抜き出したこと以外は、製造例1と同様にして、重合体粒子215.5gを得た。該重合体粒子の中位粒子径は377μmであった。 Production Example 8
In the hydrogel polymer after the second stage polymerization, 215.5 g of polymer particles were obtained in the same manner as in Production Example 1 except that 261.5 g of water was extracted from the system by azeotropic distillation. It was. The medium particle size of the polymer particles was 377 μm.
第2段目の重合後の含水ゲル状重合体において、共沸蒸留により261.5gの水を系外へ抜き出したこと以外は、製造例1と同様にして、重合体粒子215.5gを得た。該重合体粒子の中位粒子径は377μmであった。 Production Example 8
In the hydrogel polymer after the second stage polymerization, 215.5 g of polymer particles were obtained in the same manner as in Production Example 1 except that 261.5 g of water was extracted from the system by azeotropic distillation. It was. The medium particle size of the polymer particles was 377 μm.
製造例9
第1段目重合の反応における水溶性ラジカル重合開始剤を2,2’-アゾビス(2-アミジノプロパン)2塩酸塩を用いずに、過硫酸カリウム0.0736g(0.272ミリモル)に変更し、第2段目の重合反応における水溶性ラジカル重合開始剤を2,2’-アゾビス(2-アミジノプロパン)2塩酸塩を用いずに、過硫酸カリウム0.090g(0.333ミリモル)に変更したこと、共沸蒸留により256.1gの水を系外へ抜き出したこと以外は、製造例1と同様にして、重合体粒子226.4gを得た。該重合体粒子の中位粒子径は417μmであった。 Manufacturing example 9
The water-soluble radical polymerization initiator in the first-stage polymerization reaction was changed to 0.0736 g (0.272 mmol) of potassium persulfate without using 2,2'-azobis (2-amidinopropane) dihydrochloride. , The water-soluble radical polymerization initiator in the second-stage polymerization reaction was changed to 0.090 g (0.333 mmol) of potassium persulfate without using 2,2'-azobis (2-amidinopropane) dihydrochloride. In the same manner as in Production Example 1, 226.4 g of polymer particles was obtained in the same manner as in Production Example 1, except that 256.1 g of water was extracted from the system by radical distillation. The medium particle size of the polymer particles was 417 μm.
第1段目重合の反応における水溶性ラジカル重合開始剤を2,2’-アゾビス(2-アミジノプロパン)2塩酸塩を用いずに、過硫酸カリウム0.0736g(0.272ミリモル)に変更し、第2段目の重合反応における水溶性ラジカル重合開始剤を2,2’-アゾビス(2-アミジノプロパン)2塩酸塩を用いずに、過硫酸カリウム0.090g(0.333ミリモル)に変更したこと、共沸蒸留により256.1gの水を系外へ抜き出したこと以外は、製造例1と同様にして、重合体粒子226.4gを得た。該重合体粒子の中位粒子径は417μmであった。 Manufacturing example 9
The water-soluble radical polymerization initiator in the first-stage polymerization reaction was changed to 0.0736 g (0.272 mmol) of potassium persulfate without using 2,2'-azobis (2-amidinopropane) dihydrochloride. , The water-soluble radical polymerization initiator in the second-stage polymerization reaction was changed to 0.090 g (0.333 mmol) of potassium persulfate without using 2,2'-azobis (2-amidinopropane) dihydrochloride. In the same manner as in Production Example 1, 226.4 g of polymer particles was obtained in the same manner as in Production Example 1, except that 256.1 g of water was extracted from the system by radical distillation. The medium particle size of the polymer particles was 417 μm.
<吸水性樹脂粒子の作製>
実施例1
製造例1で得られた重合体粒子30gと、乾式シリカA(キャボットジャパン株式会社、M-5)0.15gとを混合し、乾式シリカを含む吸水性樹脂粒子を得た。 <Preparation of water-absorbent resin particles>
Example 1
30 g of the polymer particles obtained in Production Example 1 and 0.15 g of dry silica A (Cabot Japan Co., Ltd., M-5) were mixed to obtain water-absorbent resin particles containing dry silica.
実施例1
製造例1で得られた重合体粒子30gと、乾式シリカA(キャボットジャパン株式会社、M-5)0.15gとを混合し、乾式シリカを含む吸水性樹脂粒子を得た。 <Preparation of water-absorbent resin particles>
Example 1
30 g of the polymer particles obtained in Production Example 1 and 0.15 g of dry silica A (Cabot Japan Co., Ltd., M-5) were mixed to obtain water-absorbent resin particles containing dry silica.
実施例2
乾式シリカA(キャボットジャパン株式会社、M-5)の添加量を0.6gに変更したこと以外は実施例1と同様にして、実施例2の吸水性樹脂粒子を得た。 Example 2
Water-absorbent resin particles of Example 2 were obtained in the same manner as in Example 1 except that the amount of dry silica A (Cabot Japan Co., Ltd., M-5) added was changed to 0.6 g.
乾式シリカA(キャボットジャパン株式会社、M-5)の添加量を0.6gに変更したこと以外は実施例1と同様にして、実施例2の吸水性樹脂粒子を得た。 Example 2
Water-absorbent resin particles of Example 2 were obtained in the same manner as in Example 1 except that the amount of dry silica A (Cabot Japan Co., Ltd., M-5) added was changed to 0.6 g.
実施例3
乾式シリカとしてキャボットジャパン株式会社製M-5の代わりに乾式シリカB(キャボットジャパン株式会社製H300)に変更したこと以外は実施例1と同様にして、実施例3の吸水性樹脂粒子を得た。 Example 3
The water-absorbent resin particles of Example 3 were obtained in the same manner as in Example 1 except that the dry silica was changed to dry silica B (H300 manufactured by Cabot Japan Co., Ltd.) instead of M-5 manufactured by Cabot Japan Co., Ltd. ..
乾式シリカとしてキャボットジャパン株式会社製M-5の代わりに乾式シリカB(キャボットジャパン株式会社製H300)に変更したこと以外は実施例1と同様にして、実施例3の吸水性樹脂粒子を得た。 Example 3
The water-absorbent resin particles of Example 3 were obtained in the same manner as in Example 1 except that the dry silica was changed to dry silica B (H300 manufactured by Cabot Japan Co., Ltd.) instead of M-5 manufactured by Cabot Japan Co., Ltd. ..
実施例4
乾式シリカB(キャボットジャパン株式会社、H300)の添加量を0.06gに変更したこと以外は実施例3と同様にして、実施例2の吸水性樹脂粒子を得た。 Example 4
The water-absorbent resin particles of Example 2 were obtained in the same manner as in Example 3 except that the amount of dry silica B (Cabot Japan Co., Ltd., H300) added was changed to 0.06 g.
乾式シリカB(キャボットジャパン株式会社、H300)の添加量を0.06gに変更したこと以外は実施例3と同様にして、実施例2の吸水性樹脂粒子を得た。 Example 4
The water-absorbent resin particles of Example 2 were obtained in the same manner as in Example 3 except that the amount of dry silica B (Cabot Japan Co., Ltd., H300) added was changed to 0.06 g.
実施例5
乾式シリカB(キャボットジャパン株式会社、H300)の添加量を0.3gに変更したこと以外は実施例3と同様にして、実施例5の吸水性樹脂粒子を得た。 Example 5
The water-absorbent resin particles of Example 5 were obtained in the same manner as in Example 3 except that the amount of dry silica B (Cabot Japan Co., Ltd., H300) added was changed to 0.3 g.
乾式シリカB(キャボットジャパン株式会社、H300)の添加量を0.3gに変更したこと以外は実施例3と同様にして、実施例5の吸水性樹脂粒子を得た。 Example 5
The water-absorbent resin particles of Example 5 were obtained in the same manner as in Example 3 except that the amount of dry silica B (Cabot Japan Co., Ltd., H300) added was changed to 0.3 g.
実施例6
乾式シリカとしてキャボットジャパン株式会社製M-5の代わりに乾式シリカC(キャボットジャパン株式会社製M3KD)に変更したこと以外は実施例1と同様にして、実施例6の吸水性樹脂粒子を得た。 Example 6
The water-absorbent resin particles of Example 6 were obtained in the same manner as in Example 1 except that the dry silica was changed to dry silica C (M3KD manufactured by Cabot Japan Co., Ltd.) instead of M-5 manufactured by Cabot Japan Co., Ltd. ..
乾式シリカとしてキャボットジャパン株式会社製M-5の代わりに乾式シリカC(キャボットジャパン株式会社製M3KD)に変更したこと以外は実施例1と同様にして、実施例6の吸水性樹脂粒子を得た。 Example 6
The water-absorbent resin particles of Example 6 were obtained in the same manner as in Example 1 except that the dry silica was changed to dry silica C (M3KD manufactured by Cabot Japan Co., Ltd.) instead of M-5 manufactured by Cabot Japan Co., Ltd. ..
実施例7
乾式シリカとしてキャボットジャパン株式会社製M-5の代わりに乾式シリカD(日本アエロジル株式会社製アエロジル200)に変更したこと以外は実施例1と同様にして、実施例7の吸水性樹脂粒子を得た。 Example 7
The water-absorbent resin particles of Example 7 were obtained in the same manner as in Example 1 except that the dry silica was changed to dry silica D (Aerosil 200 manufactured by Nippon Aerosil Co., Ltd.) instead of M-5 manufactured by Cabot Japan Co., Ltd. It was.
乾式シリカとしてキャボットジャパン株式会社製M-5の代わりに乾式シリカD(日本アエロジル株式会社製アエロジル200)に変更したこと以外は実施例1と同様にして、実施例7の吸水性樹脂粒子を得た。 Example 7
The water-absorbent resin particles of Example 7 were obtained in the same manner as in Example 1 except that the dry silica was changed to dry silica D (Aerosil 200 manufactured by Nippon Aerosil Co., Ltd.) instead of M-5 manufactured by Cabot Japan Co., Ltd. It was.
実施例8
乾式シリカD(日本アエロジル株式会社、アエロジル200)の添加量を0.06gに変更したこと以外は実施例7と同様にして、実施例8の吸水性樹脂粒子を得た。 Example 8
The water-absorbent resin particles of Example 8 were obtained in the same manner as in Example 7 except that the amount of dry silica D (Nippon Aerosil Co., Ltd., Aerosil 200) added was changed to 0.06 g.
乾式シリカD(日本アエロジル株式会社、アエロジル200)の添加量を0.06gに変更したこと以外は実施例7と同様にして、実施例8の吸水性樹脂粒子を得た。 Example 8
The water-absorbent resin particles of Example 8 were obtained in the same manner as in Example 7 except that the amount of dry silica D (Nippon Aerosil Co., Ltd., Aerosil 200) added was changed to 0.06 g.
実施例9
乾式シリカD(日本アエロジル株式会社、アエロジル200)の添加量を0.3gに変更したこと以外は実施例7と同様にして、実施例9の吸水性樹脂粒子を得た。 Example 9
Water-absorbent resin particles of Example 9 were obtained in the same manner as in Example 7 except that the amount of dry silica D (Nippon Aerosil Co., Ltd., Aerosil 200) added was changed to 0.3 g.
乾式シリカD(日本アエロジル株式会社、アエロジル200)の添加量を0.3gに変更したこと以外は実施例7と同様にして、実施例9の吸水性樹脂粒子を得た。 Example 9
Water-absorbent resin particles of Example 9 were obtained in the same manner as in Example 7 except that the amount of dry silica D (Nippon Aerosil Co., Ltd., Aerosil 200) added was changed to 0.3 g.
実施例10
製造例6で得られた重合体粒子30gと、乾式シリカA(キャボットジャパン株式会社、M-5)0.24gとを混合し、実施例10の吸水性樹脂粒子を得た。 Example 10
30 g of the polymer particles obtained in Production Example 6 and 0.24 g of dry silica A (Cabot Japan Co., Ltd., M-5) were mixed to obtain water-absorbent resin particles of Example 10.
製造例6で得られた重合体粒子30gと、乾式シリカA(キャボットジャパン株式会社、M-5)0.24gとを混合し、実施例10の吸水性樹脂粒子を得た。 Example 10
30 g of the polymer particles obtained in Production Example 6 and 0.24 g of dry silica A (Cabot Japan Co., Ltd., M-5) were mixed to obtain water-absorbent resin particles of Example 10.
実施例11
製造例6で得られた重合体粒子の代わりに製造例7で得られた重合体粒子に変更したこと以外は実施例10と同様にして、実施例11の吸水性樹脂粒子を得た。 Example 11
The water-absorbent resin particles of Example 11 were obtained in the same manner as in Example 10 except that the polymer particles obtained in Production Example 6 were replaced with the polymer particles obtained in Production Example 7.
製造例6で得られた重合体粒子の代わりに製造例7で得られた重合体粒子に変更したこと以外は実施例10と同様にして、実施例11の吸水性樹脂粒子を得た。 Example 11
The water-absorbent resin particles of Example 11 were obtained in the same manner as in Example 10 except that the polymer particles obtained in Production Example 6 were replaced with the polymer particles obtained in Production Example 7.
実施例12
製造例6で得られた重合体粒子の代わりに製造例8で得られた重合体粒子に変更したこと以外は実施例10と同様にして、実施例12の吸水性樹脂粒子を得た。 Example 12
The water-absorbent resin particles of Example 12 were obtained in the same manner as in Example 10 except that the polymer particles obtained in Production Example 6 were replaced with the polymer particles obtained in Production Example 8.
製造例6で得られた重合体粒子の代わりに製造例8で得られた重合体粒子に変更したこと以外は実施例10と同様にして、実施例12の吸水性樹脂粒子を得た。 Example 12
The water-absorbent resin particles of Example 12 were obtained in the same manner as in Example 10 except that the polymer particles obtained in Production Example 6 were replaced with the polymer particles obtained in Production Example 8.
実施例13
乾式シリカとして乾式シリカA(キャボットジャパン株式会社製M-5)の代わりに乾式シリカE(OCI Company,Ltd、KONASIL K-200)に変更したこと以外は実施例1と同様にして、実施例13の吸水性樹脂粒子を得た。 Example 13
Example 13 in the same manner as in Example 1 except that the dry silica A (M-5 manufactured by Cabot Japan Co., Ltd.) was replaced with the dry silica E (OCI Company, Ltd, KONASIL K-200) as the dry silica. Water-absorbent resin particles were obtained.
乾式シリカとして乾式シリカA(キャボットジャパン株式会社製M-5)の代わりに乾式シリカE(OCI Company,Ltd、KONASIL K-200)に変更したこと以外は実施例1と同様にして、実施例13の吸水性樹脂粒子を得た。 Example 13
Example 13 in the same manner as in Example 1 except that the dry silica A (M-5 manufactured by Cabot Japan Co., Ltd.) was replaced with the dry silica E (OCI Company, Ltd, KONASIL K-200) as the dry silica. Water-absorbent resin particles were obtained.
実施例14
製造例1で得られた重合体粒子の代わりに製造例8で得られた重合体粒子に変更したこと以外は実施例13と同様にして、実施例14の吸水性樹脂粒子を得た。 Example 14
The water-absorbent resin particles of Example 14 were obtained in the same manner as in Example 13 except that the polymer particles obtained in Production Example 1 were replaced with the polymer particles obtained in Production Example 8.
製造例1で得られた重合体粒子の代わりに製造例8で得られた重合体粒子に変更したこと以外は実施例13と同様にして、実施例14の吸水性樹脂粒子を得た。 Example 14
The water-absorbent resin particles of Example 14 were obtained in the same manner as in Example 13 except that the polymer particles obtained in Production Example 1 were replaced with the polymer particles obtained in Production Example 8.
実施例15
乾式シリカとして乾式シリカA(キャボットジャパン株式会社製M-5)の代わりに乾式シリカF(OCI Company,Ltd、KONASIL K-150)に変更したこと以外は実施例1と同様にして、実施例15の吸水性樹脂粒子を得た。 Example 15
Example 15 in the same manner as in Example 1 except that the dry silica A (M-5 manufactured by Cabot Japan Co., Ltd.) was replaced with the dry silica F (OCI Company, Ltd, KONASIL K-150) as the dry silica. Water-absorbent resin particles were obtained.
乾式シリカとして乾式シリカA(キャボットジャパン株式会社製M-5)の代わりに乾式シリカF(OCI Company,Ltd、KONASIL K-150)に変更したこと以外は実施例1と同様にして、実施例15の吸水性樹脂粒子を得た。 Example 15
Example 15 in the same manner as in Example 1 except that the dry silica A (M-5 manufactured by Cabot Japan Co., Ltd.) was replaced with the dry silica F (OCI Company, Ltd, KONASIL K-150) as the dry silica. Water-absorbent resin particles were obtained.
実施例16
製造例1で得られた重合体粒子の代わりに製造例8で得られた重合体粒子に変更したこと以外は実施例15と同様にして、実施例16の吸水性樹脂粒子を得た。 Example 16
The water-absorbent resin particles of Example 16 were obtained in the same manner as in Example 15 except that the polymer particles obtained in Production Example 1 were replaced with the polymer particles obtained in Production Example 8.
製造例1で得られた重合体粒子の代わりに製造例8で得られた重合体粒子に変更したこと以外は実施例15と同様にして、実施例16の吸水性樹脂粒子を得た。 Example 16
The water-absorbent resin particles of Example 16 were obtained in the same manner as in Example 15 except that the polymer particles obtained in Production Example 1 were replaced with the polymer particles obtained in Production Example 8.
実施例17
乾式シリカとして乾式シリカA(キャボットジャパン株式会社製M-5)の代わりに乾式シリカG(株式会社トクヤマ製、レオロシール QS-102)に変更したこと以外は実施例1と同様にして、実施例17の吸水性樹脂粒子を得た。 Example 17
Example 17 in the same manner as in Example 1 except that the dry silica A (M-5 manufactured by Cabot Japan Co., Ltd.) was replaced with the dry silica G (Reoloseal QS-102 manufactured by Tokuyama Corporation) as the dry silica. Water-absorbent resin particles were obtained.
乾式シリカとして乾式シリカA(キャボットジャパン株式会社製M-5)の代わりに乾式シリカG(株式会社トクヤマ製、レオロシール QS-102)に変更したこと以外は実施例1と同様にして、実施例17の吸水性樹脂粒子を得た。 Example 17
Example 17 in the same manner as in Example 1 except that the dry silica A (M-5 manufactured by Cabot Japan Co., Ltd.) was replaced with the dry silica G (Reoloseal QS-102 manufactured by Tokuyama Corporation) as the dry silica. Water-absorbent resin particles were obtained.
実施例18
製造例1で得られた重合体粒子の代わりに製造例9で得られた重合体粒子に変更したこと以外は実施例1と同様にして、実施例18の吸水性樹脂粒子を得た。 Example 18
The water-absorbent resin particles of Example 18 were obtained in the same manner as in Example 1 except that the polymer particles obtained in Production Example 1 were replaced with the polymer particles obtained in Production Example 9.
製造例1で得られた重合体粒子の代わりに製造例9で得られた重合体粒子に変更したこと以外は実施例1と同様にして、実施例18の吸水性樹脂粒子を得た。 Example 18
The water-absorbent resin particles of Example 18 were obtained in the same manner as in Example 1 except that the polymer particles obtained in Production Example 1 were replaced with the polymer particles obtained in Production Example 9.
比較例1
製造例2で得られた重合体粒子30gと湿式シリカ(OSC、トクシールNP-S)0.03gとを混合し、湿式シリカを含む吸水性樹脂粒子を得た。 Comparative Example 1
30 g of the polymer particles obtained in Production Example 2 and 0.03 g of wet silica (OSC, Toxil NP-S) were mixed to obtain water-absorbent resin particles containing wet silica.
製造例2で得られた重合体粒子30gと湿式シリカ(OSC、トクシールNP-S)0.03gとを混合し、湿式シリカを含む吸水性樹脂粒子を得た。 Comparative Example 1
30 g of the polymer particles obtained in Production Example 2 and 0.03 g of wet silica (OSC, Toxil NP-S) were mixed to obtain water-absorbent resin particles containing wet silica.
比較例2
製造例3で得られた重合体粒子30gと湿式シリカ(OSC、トクシールNP-S)0.06gとを混合し、湿式シリカを含む吸水性樹脂粒子を得た。 Comparative Example 2
30 g of the polymer particles obtained in Production Example 3 and 0.06 g of wet silica (OSC, Toxil NP-S) were mixed to obtain water-absorbent resin particles containing wet silica.
製造例3で得られた重合体粒子30gと湿式シリカ(OSC、トクシールNP-S)0.06gとを混合し、湿式シリカを含む吸水性樹脂粒子を得た。 Comparative Example 2
30 g of the polymer particles obtained in Production Example 3 and 0.06 g of wet silica (OSC, Toxil NP-S) were mixed to obtain water-absorbent resin particles containing wet silica.
比較例3
製造例4で得られた重合体粒子30gと湿式シリカ(OSC、トクシールNP-S)0.06gとを混合し、湿式シリカを含む吸水性樹脂粒子を得た。 Comparative Example 3
30 g of the polymer particles obtained in Production Example 4 and 0.06 g of wet silica (OSC, Toxil NP-S) were mixed to obtain water-absorbent resin particles containing wet silica.
製造例4で得られた重合体粒子30gと湿式シリカ(OSC、トクシールNP-S)0.06gとを混合し、湿式シリカを含む吸水性樹脂粒子を得た。 Comparative Example 3
30 g of the polymer particles obtained in Production Example 4 and 0.06 g of wet silica (OSC, Toxil NP-S) were mixed to obtain water-absorbent resin particles containing wet silica.
比較例4
製造例5で得られた重合体粒子30gと湿式シリカ(OSC、トクシールNP-S)0.06gとを混合し、湿式シリカを含む吸水性樹脂粒子を得た。 Comparative Example 4
30 g of the polymer particles obtained in Production Example 5 and 0.06 g of wet silica (OSC, Toxil NP-S) were mixed to obtain water-absorbent resin particles containing wet silica.
製造例5で得られた重合体粒子30gと湿式シリカ(OSC、トクシールNP-S)0.06gとを混合し、湿式シリカを含む吸水性樹脂粒子を得た。 Comparative Example 4
30 g of the polymer particles obtained in Production Example 5 and 0.06 g of wet silica (OSC, Toxil NP-S) were mixed to obtain water-absorbent resin particles containing wet silica.
比較例5
製造例1で得られた重合体粒子30gと湿式シリカ(OSC、トクシールNP-S)0.06gとを重合体粒子と混合し、湿式シリカを含む吸水性樹脂粒子を得た。 Comparative Example 5
30 g of the polymer particles obtained in Production Example 1 and 0.06 g of wet silica (OSC, Toxile NP-S) were mixed with the polymer particles to obtain water-absorbent resin particles containing the wet silica.
製造例1で得られた重合体粒子30gと湿式シリカ(OSC、トクシールNP-S)0.06gとを重合体粒子と混合し、湿式シリカを含む吸水性樹脂粒子を得た。 Comparative Example 5
30 g of the polymer particles obtained in Production Example 1 and 0.06 g of wet silica (OSC, Toxile NP-S) were mixed with the polymer particles to obtain water-absorbent resin particles containing the wet silica.
比較例6
乾式シリカA(キャボットジャパン株式会社、M-5)を添加せずに製造例1にて得られた重合体粒子を比較例6の吸水性樹脂粒子として用いた。 Comparative Example 6
The polymer particles obtained in Production Example 1 without adding dry silica A (Cabot Japan Co., Ltd., M-5) were used as the water-absorbent resin particles of Comparative Example 6.
乾式シリカA(キャボットジャパン株式会社、M-5)を添加せずに製造例1にて得られた重合体粒子を比較例6の吸水性樹脂粒子として用いた。 Comparative Example 6
The polymer particles obtained in Production Example 1 without adding dry silica A (Cabot Japan Co., Ltd., M-5) were used as the water-absorbent resin particles of Comparative Example 6.
2.評価
<生理食塩水保水量>
吸水性樹脂粒子の生理食塩水保水量(室温、25℃±2℃)を下記手順で測定した。まず、吸水性樹脂粒子2.0gを量り取った綿袋(メンブロード60番、横100mm×縦200mm)を500mL容のビーカー内に設置した。吸水性樹脂粒子の入った綿袋中に0.9質量%塩化ナトリウム水溶液(生理食塩水)500gをママコができないように一度に注ぎ込み、綿袋の上部を輪ゴムで縛り、30分静置させることで吸水性樹脂粒子を膨潤させた。30分経過後の綿袋を、遠心力が167Gとなるよう設定した脱水機(株式会社コクサン製、品番:H-122)を用いて1分間脱水し、脱水後の膨潤ゲルを含んだ綿袋の質量Wa(g)を測定した。吸水性樹脂粒子を添加せずに同様の操作を行い、綿袋の湿潤時の空質量Wb(g)を測定し、以下の式から生理食塩水保水量を算出した。
生理食塩水保水量(g/g)=[Wa-Wb]/2.0 2. Evaluation <Saline water retention>
The physiological saline water retention amount (room temperature, 25 ° C. ± 2 ° C.) of the water-absorbent resin particles was measured by the following procedure. First, a cotton bag (Membroad No. 60,width 100 mm x length 200 mm) weighing 2.0 g of water-absorbent resin particles was placed in a 500 mL beaker. Pour 500 g of 0.9 mass% sodium chloride aqueous solution (physiological saline) into a cotton bag containing water-absorbent resin particles at a time so that mamaco cannot be formed, tie the upper part of the cotton bag with a rubber ring, and let it stand for 30 minutes. The water-absorbent resin particles were swollen with. After 30 minutes, the cotton bag is dehydrated for 1 minute using a dehydrator (manufactured by Kokusan Co., Ltd., product number: H-122) set to have a centrifugal force of 167 G, and the cotton bag containing the swelling gel after dehydration. The mass Wa (g) of was measured. The same operation was performed without adding the water-absorbent resin particles, the empty mass Wb (g) of the cotton bag when wet was measured, and the amount of physiological saline water retained was calculated from the following formula.
Saline water retention (g / g) = [Wa-Wb] /2.0
<生理食塩水保水量>
吸水性樹脂粒子の生理食塩水保水量(室温、25℃±2℃)を下記手順で測定した。まず、吸水性樹脂粒子2.0gを量り取った綿袋(メンブロード60番、横100mm×縦200mm)を500mL容のビーカー内に設置した。吸水性樹脂粒子の入った綿袋中に0.9質量%塩化ナトリウム水溶液(生理食塩水)500gをママコができないように一度に注ぎ込み、綿袋の上部を輪ゴムで縛り、30分静置させることで吸水性樹脂粒子を膨潤させた。30分経過後の綿袋を、遠心力が167Gとなるよう設定した脱水機(株式会社コクサン製、品番:H-122)を用いて1分間脱水し、脱水後の膨潤ゲルを含んだ綿袋の質量Wa(g)を測定した。吸水性樹脂粒子を添加せずに同様の操作を行い、綿袋の湿潤時の空質量Wb(g)を測定し、以下の式から生理食塩水保水量を算出した。
生理食塩水保水量(g/g)=[Wa-Wb]/2.0 2. Evaluation <Saline water retention>
The physiological saline water retention amount (room temperature, 25 ° C. ± 2 ° C.) of the water-absorbent resin particles was measured by the following procedure. First, a cotton bag (Membroad No. 60,
Saline water retention (g / g) = [Wa-Wb] /2.0
<中位粒子径>
重合体粒子(もしくは吸水性樹脂粒子)50gを中位粒子径測定用に用いた。 <Medium particle size>
50 g of polymer particles (or water-absorbent resin particles) were used for measuring the medium particle size.
重合体粒子(もしくは吸水性樹脂粒子)50gを中位粒子径測定用に用いた。 <Medium particle size>
50 g of polymer particles (or water-absorbent resin particles) were used for measuring the medium particle size.
JIS標準篩を上から、目開き850μmの篩、目開き500μmの篩、目開き425μmの篩、目開き300μmの篩、目開き250μmの篩、目開き180μmの篩、目開き150μmの篩、及び受け皿の順に組み合わせた。
From the top, JIS standard sieves have a mesh size of 850 μm, a mesh size of 500 μm, a mesh size of 425 μm, a mesh size of 300 μm, a mesh size of 250 μm, a mesh size of 180 μm, a mesh size of 150 μm, Combined in the order of the saucer.
組み合わせた最上の篩に、重合体粒子(もしくは吸水性樹脂粒子)を入れ、ロータップ式振とう器を用いてJIS Z 8815(1994)に準じて20分間振とうさせて分級した。分級後、各篩上に残った重合体粒子(もしくは吸水性樹脂粒子)の質量を全量に対する質量百分率として算出し粒度分布を求めた。この粒度分布に関して粒子径の大きい方から順に篩上を積算することにより、篩の目開きと篩上に残った重合体粒子(もしくは吸水性樹脂粒子)の質量百分率の積算値との関係を対数確率紙にプロットした。確率紙上のプロットを直線で結ぶことにより、積算質量百分率50質量%に相当する粒子径を中位粒子径とした。
Polymer particles (or water-absorbent resin particles) were placed in the best combined sieve and shaken for 20 minutes according to JIS Z8815 (1994) using a low-tap shaker to classify. After classification, the mass of the polymer particles (or water-absorbent resin particles) remaining on each sieve was calculated as a mass percentage with respect to the total amount, and the particle size distribution was determined. By integrating on the sieve in order from the one with the largest particle size with respect to this particle size distribution, the relationship between the mesh size of the sieve and the integrated value of the mass percentage of the polymer particles (or water-absorbent resin particles) remaining on the sieve is logarithmic. Plotted on probability paper. 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 defined as the medium particle size.
<無加圧DW>
吸水性樹脂粒子の無加圧DWは、図2に示す測定装置を用いて測定した。測定は1種類の吸水性樹脂粒子に関して5回実施し、最低値と最高値とを除いた3点の測定値の平均値を求めた。
当該測定装置は、ビュレット部1、導管5、測定台13、ナイロンメッシュシート15、架台11、及びクランプ3を有する。ビュレット部1は、目盛が記載されたビュレット管21と、ビュレット管21の上部の開口を密栓するゴム栓23と、ビュレット管21の下部の先端に連結されたコック22と、ビュレット管21の下部に連結された空気導入管25及びコック24とを有する。ビュレット部1はクランプ3で固定されている。平板状の測定台13は、その中央部に形成された直径2mmの貫通孔13aを有しており、高さが可変の架台11によって支持されている。測定台13の貫通孔13aとビュレット部1のコック22とが導管5によって連結されている。導管5の内径は6mmである。 <Unpressurized DW>
The non-pressurized DW of the water-absorbent resin particles was measured using the measuring device shown in FIG. The measurement was carried out 5 times for one type of water-absorbent resin particles, and the average value of the measured values at three points excluding the minimum value and the maximum value was obtained.
The measuring device has aburette portion 1, a conduit 5, a measuring table 13, a nylon mesh sheet 15, a frame 11, and a clamp 3. The burette portion 1 includes a burette tube 21 on which a scale is described, a rubber stopper 23 for sealing the upper opening of the burette tube 21, a cock 22 connected to the tip of the lower portion of the burette tube 21, and a lower portion of the burette tube 21. It has an air introduction pipe 25 and a cock 24 connected to the burette. The burette portion 1 is fixed by a clamp 3. The flat plate-shaped measuring table 13 has a through hole 13a having a diameter of 2 mm formed in the central portion thereof, and is supported by a frame 11 having a variable height. The through hole 13a of the measuring table 13 and the cock 22 of the burette portion 1 are connected by a conduit 5. The inner diameter of the conduit 5 is 6 mm.
吸水性樹脂粒子の無加圧DWは、図2に示す測定装置を用いて測定した。測定は1種類の吸水性樹脂粒子に関して5回実施し、最低値と最高値とを除いた3点の測定値の平均値を求めた。
当該測定装置は、ビュレット部1、導管5、測定台13、ナイロンメッシュシート15、架台11、及びクランプ3を有する。ビュレット部1は、目盛が記載されたビュレット管21と、ビュレット管21の上部の開口を密栓するゴム栓23と、ビュレット管21の下部の先端に連結されたコック22と、ビュレット管21の下部に連結された空気導入管25及びコック24とを有する。ビュレット部1はクランプ3で固定されている。平板状の測定台13は、その中央部に形成された直径2mmの貫通孔13aを有しており、高さが可変の架台11によって支持されている。測定台13の貫通孔13aとビュレット部1のコック22とが導管5によって連結されている。導管5の内径は6mmである。 <Unpressurized DW>
The non-pressurized DW of the water-absorbent resin particles was measured using the measuring device shown in FIG. The measurement was carried out 5 times for one type of water-absorbent resin particles, and the average value of the measured values at three points excluding the minimum value and the maximum value was obtained.
The measuring device has a
測定は温度25℃、湿度60±10%の環境下で行なわれた。まずビュレット部1のコック22とコック24を閉め、25℃に調節された0.9質量%食塩水50をビュレット管21上部の開口からビュレット管21に入れた。食塩水の濃度0.9質量%は、食塩水の質量を基準とする濃度である。ゴム栓23でビュレット管21の開口の密栓した後、コック22及びコック24を開けた。気泡が入らないよう導管5内部を0.9質量%食塩水50で満たした。貫通孔13a内に到達した0.9質量%食塩水の水面の高さが、測定台13の上面の高さと同じになるように、測定台13の高さを調整した。調整後、ビュレット管21内の0.9質量%食塩水50の水面の高さをビュレット管21の目盛で読み取り、その位置をゼロ点(0秒時点の読み値)とした。
The measurement was performed in an environment with a temperature of 25 ° C and a humidity of 60 ± 10%. First, the cock 22 and the cock 24 of the burette portion 1 were closed, and 0.9 mass% saline solution 50 adjusted to 25 ° C. was put into the burette tube 21 through the opening at the upper part of the burette tube 21. The concentration of 0.9% by mass of the saline solution is a concentration based on the mass of the saline solution. After sealing the opening of the burette tube 21 with the rubber stopper 23, the cock 22 and the cock 24 were opened. The inside of the conduit 5 was filled with 0.9% by mass saline solution 50 to prevent air bubbles from entering. The height of the measuring table 13 was adjusted so that the height of the water surface of the 0.9% by mass saline solution that reached the inside of the through hole 13a was the same as the height of the upper surface of the measuring table 13. After the adjustment, the height of the water surface of the 0.9 mass% saline solution 50 in the burette tube 21 was read by the scale of the burette tube 21, and the position was set as the zero point (reading value at 0 seconds).
測定台13上の貫通孔13aの近傍にてナイロンメッシュシート15(100mm×100mm、250メッシュ、厚さ約50μm)を敷き、その中央部に、内径30mm、高さ20mmのシリンダーを置いた。このシリンダーに、1.00gの吸水性樹脂粒子10aを均一に散布した。その後、シリンダーを注意深く取り除き、ナイロンメッシュシート15の中央部に吸水性樹脂粒子10aが円状に分散されたサンプルを得た。次いで、吸水性樹脂粒子10aが載置されたナイロンメッシュシート15を、その中心が貫通孔13aの位置になるように、吸水性樹脂粒子10aが散逸しない程度にすばやく移動させて、測定を開始した。空気導入管25からビュレット管21内に気泡が最初に導入された時点を吸水開始(0秒)とした。
A nylon mesh sheet 15 (100 mm × 100 mm, 250 mesh, thickness about 50 μm) was laid in the vicinity of the through hole 13a on the measuring table 13, and a cylinder having an inner diameter of 30 mm and a height of 20 mm was placed in the center thereof. 1.00 g of water-absorbent resin particles 10a were uniformly sprayed on this cylinder. Then, the cylinder was carefully removed to obtain a sample in which the water-absorbent resin particles 10a were dispersed in a circle in the central portion of the nylon mesh sheet 15. Next, the nylon mesh sheet 15 on which the water-absorbent resin particles 10a were placed was quickly moved so that the center thereof was at the position of the through hole 13a so that the water-absorbent resin particles 10a did not dissipate, and the measurement was started. .. The time when the air bubbles were first introduced from the air introduction pipe 25 into the burette pipe 21 was defined as the start of water absorption (0 seconds).
ビュレット管21内の0.9質量%食塩水50の減少量(すなわち、吸水性樹脂粒子10aが吸水した0.9質量%食塩水の量)を0.1mL単位で順次読み取り、吸水性樹脂粒子10aの吸水開始から起算して10秒後、1分後、3分後、5分後及び10分後の0.9質量%食塩水50の減量分Wc(g)を読み取った。Wcから、下記式により無加圧DWの10秒値、1分値、3分値、5分値及び10分値を求めた。無加圧DWは、吸水性樹脂粒子10aの1.00g当たりの吸水量である。
無加圧DW値(mL/g)=Wc/1.00 The amount of decrease in the 0.9% bymass saline solution 50 in the bullet tube 21 (that is, the amount of the 0.9% by mass saline solution absorbed by the water-absorbent resin particles 10a) is sequentially read in units of 0.1 mL, and the water-absorbent resin particles are read. 10 seconds, 1 minute, 3 minutes, 5 minutes, and 10 minutes after the start of water absorption of 10a, the weight loss Wc (g) of 0.9% by mass saline solution was read. From Wc, the 10-second value, 1-minute value, 3-minute value, 5-minute value, and 10-minute value of the non-pressurized DW were obtained by the following formula. The non-pressurized DW is the amount of water absorbed per 1.00 g of the water-absorbent resin particles 10a.
Unpressurized DW value (mL / g) = Wc / 1.00
無加圧DW値(mL/g)=Wc/1.00 The amount of decrease in the 0.9% by
Unpressurized DW value (mL / g) = Wc / 1.00
<吸収体における漏れ性の簡易評価>
(1)人工尿の調製
塩化ナトリウム、塩化カルシウム及び硫酸マグネシウムを下記の濃度でイオン交換水に溶解させた。得られた溶液に少量の青色1号加えて、青色に着色した人工尿を得た。得られた人工尿を、漏れ性評価のための試験液として用いた。下記の濃度は、人工尿の全質量を基準とする濃度である。
人工尿組成
NaCl:0.780質量%
CaCl2:0.022質量%
MgSO4:0.038質量%
青色一号:0.002質量% <Simple evaluation of leakability in absorber>
(1) Preparation of artificial urine Sodium chloride, calcium chloride and magnesium sulfate were dissolved in ion-exchanged water at the following concentrations. A small amount of Blue No. 1 was added to the obtained solution to obtain artificial urine colored blue. The obtained artificial urine was used as a test solution for evaluating leakability. The following concentrations are based on the total mass of artificial urine.
Artificial urine composition NaCl: 0.780% by mass
CaCl 2 : 0.022% by mass
0054 4 : 0.038% by mass
Blue No. 1: 0.002% by mass
(1)人工尿の調製
塩化ナトリウム、塩化カルシウム及び硫酸マグネシウムを下記の濃度でイオン交換水に溶解させた。得られた溶液に少量の青色1号加えて、青色に着色した人工尿を得た。得られた人工尿を、漏れ性評価のための試験液として用いた。下記の濃度は、人工尿の全質量を基準とする濃度である。
人工尿組成
NaCl:0.780質量%
CaCl2:0.022質量%
MgSO4:0.038質量%
青色一号:0.002質量% <Simple evaluation of leakability in absorber>
(1) Preparation of artificial urine Sodium chloride, calcium chloride and magnesium sulfate were dissolved in ion-exchanged water at the following concentrations. A small amount of Blue No. 1 was added to the obtained solution to obtain artificial urine colored blue. The obtained artificial urine was used as a test solution for evaluating leakability. The following concentrations are based on the total mass of artificial urine.
Artificial urine composition NaCl: 0.780% by mass
CaCl 2 : 0.022% by mass
0054 4 : 0.038% by mass
Blue No. 1: 0.002% by mass
(2)漏れ性試験
図3は、吸収体の漏れ性を簡易的に評価する装置を示す模式図である。図3に示される装置を用いて、以下のi)、ii)、iii)、iv)及びv)の手順により、試験用吸収体の液体漏れ性を評価した。
i)長さ15cm、幅5cmの短冊状の粘着テープ(ダイヤテックス株式会社製、パイオランテープ)を粘着面が上になるよう実験台上に置き、その粘着面上に、吸水性樹脂粒子3.0gを均一に散布した。散布された吸水性樹脂粒子の上部に、ステンレス製ローラー(質量4.0kg、径10.5cm、幅6.0cm)を載せ、ローラーを、粘着テープの長手方向における両端の間で3回往復させた。これにより、吸水性樹脂粒子からなる吸水層を粘着テープの粘着面上に形成した(試験用吸収体)。
ii)粘着テープを垂直に立てて持ち上げ、余剰の吸水性樹脂粒子を吸水層から除いた。再度、吸水層に前記ローラーを載せ、粘着テープの長手方向における両端の間で3回往復させた。
iii)温度25±2℃の室内において、長さ30cm、幅55cmの長方形の平坦な主面S1を有するアクリル樹脂板45を、その幅方向が水平面S0に平行で、その主面S1と水平面S0とが30度をなすように固定した。固定されたアクリル樹脂板45の主面S1に、吸水層が形成された粘着テープ(試験用吸収体)46を、吸水層が露出し、その長手方向がアクリル樹脂板45の幅方向に対して垂直になる向きで貼り付けた。
iv)吸水層の上端から約1cmの位置で表面から約1cmの高さから、液温25℃の試験液0.25mLを、マイクロピペット47(エムエス機器社製ピペットマン・ネオP1000N)を用いて、1秒以内に全て注入した。
v)試験液55の注入開始から30秒後に、吸水層に注入された試験液55の移動距離の最大値を読み取り、拡散距離Dとして記録した。なお、拡散距離Dは、主面上において、滴下点(注入点)と最長到達点とを、アクリル樹脂板45の短辺に対して垂直方向の直線で結んだ距離である。 (2) Leakage test FIG. 3 is a schematic view showing an apparatus for simply evaluating the leakability of an absorber. Using the apparatus shown in FIG. 3, the liquid leakage property of the test absorber was evaluated by the following procedures i), ii), iii), iv) and v).
i) A strip-shaped adhesive tape (manufactured by Diatex Co., Ltd., Piolan tape) having a length of 15 cm and a width of 5 cm is placed on a laboratory table so that the adhesive surface faces up, and the water-absorbent resin particles 3 are placed on the adhesive surface. .0 g was evenly sprayed. A stainless steel roller (mass 4.0 kg, diameter 10.5 cm, width 6.0 cm) is placed on top of the sprayed water-absorbent resin particles, and the roller is reciprocated three times between both ends in the longitudinal direction of the adhesive tape. It was. As a result, a water-absorbing layer made of water-absorbent resin particles was formed on the adhesive surface of the adhesive tape (test absorber).
ii) The adhesive tape was lifted upright to remove excess water-absorbent resin particles from the water-absorbent layer. Again, the roller was placed on the water absorption layer and reciprocated three times between both ends of the adhesive tape in the longitudinal direction.
iii) In a room at a temperature of 25 ± 2 ° C., anacrylic resin plate 45 having a rectangular flat main surface S 1 having a length of 30 cm and a width of 55 cm is arranged in a width direction parallel to a horizontal plane S 0 , and the main surface S 1 And the horizontal plane S 0 were fixed so as to form 30 degrees. The main surface S 1 of the fixed acrylic plate 45, the adhesive tape (test absorber) 46 water-absorbing layer is formed, the water-absorbing layer is exposed, its longitudinal direction with respect to the width direction of the acrylic resin plate 45 It was pasted in a vertical orientation.
iv) Using a micropipette 47 (Pipetteman Neo P1000N manufactured by MS Equipment Co., Ltd.), 0.25 mL of the test solution at a liquid temperature of 25 ° C. was applied from a height of about 1 cm from the surface at a position about 1 cm from the upper end of the water absorption layer. All were injected within 1 second.
v) Thirty seconds after the start of injection of thetest solution 55, the maximum value of the moving distance of the test solution 55 injected into the water absorption layer was read and recorded as the diffusion distance D. The diffusion distance D is a distance on the main surface connecting the dropping point (injection point) and the longest reaching point with a straight line in the direction perpendicular to the short side of the acrylic resin plate 45.
図3は、吸収体の漏れ性を簡易的に評価する装置を示す模式図である。図3に示される装置を用いて、以下のi)、ii)、iii)、iv)及びv)の手順により、試験用吸収体の液体漏れ性を評価した。
i)長さ15cm、幅5cmの短冊状の粘着テープ(ダイヤテックス株式会社製、パイオランテープ)を粘着面が上になるよう実験台上に置き、その粘着面上に、吸水性樹脂粒子3.0gを均一に散布した。散布された吸水性樹脂粒子の上部に、ステンレス製ローラー(質量4.0kg、径10.5cm、幅6.0cm)を載せ、ローラーを、粘着テープの長手方向における両端の間で3回往復させた。これにより、吸水性樹脂粒子からなる吸水層を粘着テープの粘着面上に形成した(試験用吸収体)。
ii)粘着テープを垂直に立てて持ち上げ、余剰の吸水性樹脂粒子を吸水層から除いた。再度、吸水層に前記ローラーを載せ、粘着テープの長手方向における両端の間で3回往復させた。
iii)温度25±2℃の室内において、長さ30cm、幅55cmの長方形の平坦な主面S1を有するアクリル樹脂板45を、その幅方向が水平面S0に平行で、その主面S1と水平面S0とが30度をなすように固定した。固定されたアクリル樹脂板45の主面S1に、吸水層が形成された粘着テープ(試験用吸収体)46を、吸水層が露出し、その長手方向がアクリル樹脂板45の幅方向に対して垂直になる向きで貼り付けた。
iv)吸水層の上端から約1cmの位置で表面から約1cmの高さから、液温25℃の試験液0.25mLを、マイクロピペット47(エムエス機器社製ピペットマン・ネオP1000N)を用いて、1秒以内に全て注入した。
v)試験液55の注入開始から30秒後に、吸水層に注入された試験液55の移動距離の最大値を読み取り、拡散距離Dとして記録した。なお、拡散距離Dは、主面上において、滴下点(注入点)と最長到達点とを、アクリル樹脂板45の短辺に対して垂直方向の直線で結んだ距離である。 (2) Leakage test FIG. 3 is a schematic view showing an apparatus for simply evaluating the leakability of an absorber. Using the apparatus shown in FIG. 3, the liquid leakage property of the test absorber was evaluated by the following procedures i), ii), iii), iv) and v).
i) A strip-shaped adhesive tape (manufactured by Diatex Co., Ltd., Piolan tape) having a length of 15 cm and a width of 5 cm is placed on a laboratory table so that the adhesive surface faces up, and the water-absorbent resin particles 3 are placed on the adhesive surface. .0 g was evenly sprayed. A stainless steel roller (mass 4.0 kg, diameter 10.5 cm, width 6.0 cm) is placed on top of the sprayed water-absorbent resin particles, and the roller is reciprocated three times between both ends in the longitudinal direction of the adhesive tape. It was. As a result, a water-absorbing layer made of water-absorbent resin particles was formed on the adhesive surface of the adhesive tape (test absorber).
ii) The adhesive tape was lifted upright to remove excess water-absorbent resin particles from the water-absorbent layer. Again, the roller was placed on the water absorption layer and reciprocated three times between both ends of the adhesive tape in the longitudinal direction.
iii) In a room at a temperature of 25 ± 2 ° C., an
iv) Using a micropipette 47 (Pipetteman Neo P1000N manufactured by MS Equipment Co., Ltd.), 0.25 mL of the test solution at a liquid temperature of 25 ° C. was applied from a height of about 1 cm from the surface at a position about 1 cm from the upper end of the water absorption layer. All were injected within 1 second.
v) Thirty seconds after the start of injection of the
3.結果
評価結果を表1及び表2に示す。拡散距離の「14*」は、吸水層の下部からの試験液の漏れが発生したことを示す。表1~2中の添加量は、重合体粒子100質量部に対するシリカの添加量を示す。 3. 3. Results The evaluation results are shown in Tables 1 and 2. A diffusion distance of "14 *" indicates that the test solution leaked from the lower part of the water absorption layer. The addition amount in Tables 1 and 2 indicates the addition amount of silica with respect to 100 parts by mass of the polymer particles.
評価結果を表1及び表2に示す。拡散距離の「14*」は、吸水層の下部からの試験液の漏れが発生したことを示す。表1~2中の添加量は、重合体粒子100質量部に対するシリカの添加量を示す。 3. 3. Results The evaluation results are shown in Tables 1 and 2. A diffusion distance of "14 *" indicates that the test solution leaked from the lower part of the water absorption layer. The addition amount in Tables 1 and 2 indicates the addition amount of silica with respect to 100 parts by mass of the polymer particles.
表1及び表2に示すとおり、液体漏れ抑制剤としての乾式シリカを含む場合、液体漏れが抑制されていた。
As shown in Tables 1 and 2, when dry silica as a liquid leakage inhibitor was contained, liquid leakage was suppressed.
1…ビュレット部、3…クランプ、5…導管、10…吸収体、10a…吸水性樹脂粒子、10b…繊維層、11…架台、13…測定台、13a…貫通孔、15…ナイロンメッシュシート、20a,20b…コアラップ、21…ビュレット管、22…コック、23…ゴム栓、24…コック、25…空気導入管、50…0.9質量%食塩水、30…液体透過性シート、40…液体不透過性シート、45…アクリル樹脂板、46…試験用吸収体、47…マイクロピペット、55…試験液、100…吸収性物品。
1 ... Burette part, 3 ... Clamp, 5 ... Conduit, 10 ... Absorbent, 10a ... Water-absorbent resin particles, 10b ... Fiber layer, 11 ... Stand, 13 ... Measuring table, 13a ... Through hole, 15 ... Nylon mesh sheet, 20a, 20b ... core wrap, 21 ... burette tube, 22 ... cock, 23 ... rubber stopper, 24 ... cock, 25 ... air introduction tube, 50 ... 0.9% by mass saline solution, 30 ... liquid permeable sheet, 40 ... liquid Impermeable sheet, 45 ... acrylic resin plate, 46 ... test absorber, 47 ... micropipette, 55 ... test solution, 100 ... absorbent article.
1 ... Burette part, 3 ... Clamp, 5 ... Conduit, 10 ... Absorbent, 10a ... Water-absorbent resin particles, 10b ... Fiber layer, 11 ... Stand, 13 ... Measuring table, 13a ... Through hole, 15 ... Nylon mesh sheet, 20a, 20b ... core wrap, 21 ... burette tube, 22 ... cock, 23 ... rubber stopper, 24 ... cock, 25 ... air introduction tube, 50 ... 0.9% by mass saline solution, 30 ... liquid permeable sheet, 40 ... liquid Impermeable sheet, 45 ... acrylic resin plate, 46 ... test absorber, 47 ... micropipette, 55 ... test solution, 100 ... absorbent article.
Claims (6)
- 乾式シリカを含む、吸水性樹脂粒子を含有する吸収体に用いられる、液体漏れ抑制剤。 A liquid leakage inhibitor used for absorbers containing water-absorbent resin particles, including dry silica.
- 前記乾式シリカの嵩密度が10~200g/Lである、請求項1に記載の液体漏れ抑制剤。 The liquid leakage inhibitor according to claim 1, wherein the dry silica has a bulk density of 10 to 200 g / L.
- 重合体粒子と、該重合体粒子の表面に配置した請求項1又は2に記載の液体漏れ抑制剤とを含む、吸水性樹脂粒子。 A water-absorbent resin particle containing the polymer particles and the liquid leakage inhibitor according to claim 1 or 2 arranged on the surface of the polymer particles.
- 前記吸水性樹脂粒子が、下記式で算出される静的吸引指数αが5.0mL/g以上である請求項3に記載の吸水性樹脂粒子。
式:α=(I+II)/2
ここで、
吸水速度指数I=(無加圧DWの10秒値)×6[mL/g]
吸水速度指数II=(無加圧DWの3分値)/3[mL/g]
である。 The water-absorbent resin particles according to claim 3, wherein the water-absorbent resin particles have a static suction index α of 5.0 mL / g or more calculated by the following formula.
Formula: α = (I + II) / 2
here,
Water absorption rate index I = (10-second value of non-pressurized DW) x 6 [mL / g]
Water absorption rate index II = (3 minutes value of non-pressurized DW) / 3 [mL / g]
Is. - 請求項3又は4に記載の吸水性樹脂粒子を含有する、吸収体。 An absorber containing the water-absorbent resin particles according to claim 3 or 4.
- 請求項5に記載の吸収体を備える、吸収性物品。
An absorbent article comprising the absorber according to claim 5.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2021545625A JPWO2021049631A1 (en) | 2019-09-13 | 2020-09-11 |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2019-167050 | 2019-09-13 | ||
JP2019167050 | 2019-09-13 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2021049631A1 true WO2021049631A1 (en) | 2021-03-18 |
Family
ID=74865744
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2020/034535 WO2021049631A1 (en) | 2019-09-13 | 2020-09-11 | Liquid leakage inhibitor used in absorbent containing water absorbent resin particles, and water absorbent resin particles |
Country Status (2)
Country | Link |
---|---|
JP (1) | JPWO2021049631A1 (en) |
WO (1) | WO2021049631A1 (en) |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2017164356A (en) * | 2016-03-17 | 2017-09-21 | 株式会社リブドゥコーポレーション | Absorbent article |
JP2018059124A (en) * | 2010-09-06 | 2018-04-12 | 住友精化株式会社 | Water absorbent resin |
JP2019038882A (en) * | 2017-08-23 | 2019-03-14 | 花王株式会社 | Water-absorbing resin composition |
-
2020
- 2020-09-11 WO PCT/JP2020/034535 patent/WO2021049631A1/en active Application Filing
- 2020-09-11 JP JP2021545625A patent/JPWO2021049631A1/ja active Pending
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2018059124A (en) * | 2010-09-06 | 2018-04-12 | 住友精化株式会社 | Water absorbent resin |
JP2017164356A (en) * | 2016-03-17 | 2017-09-21 | 株式会社リブドゥコーポレーション | Absorbent article |
JP2019038882A (en) * | 2017-08-23 | 2019-03-14 | 花王株式会社 | Water-absorbing resin composition |
Also Published As
Publication number | Publication date |
---|---|
JPWO2021049631A1 (en) | 2021-03-18 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US10265226B2 (en) | Water-absorbent resin, water-absorbent material, and water-absorbent article | |
WO2020122209A1 (en) | Water absorbent resin particles | |
EP3896097A1 (en) | Water-absorptive resin particle, absorption body, and absorptive article | |
JP6828222B1 (en) | A method for producing water-absorbent resin particles, an absorbent article, a method for producing water-absorbent resin particles, and a method for increasing the amount of absorption of the absorber under pressure. | |
WO2020184386A1 (en) | Water absorbing resin particles, absorbent article, method for manufacturing water absorbing resin particles, method for facilitating permeation of physiological saline solution into absorbent body | |
EP3896095A1 (en) | Water-absorbent resin particles, absorbent body, and absorbent article | |
JP6681494B1 (en) | Water absorbent resin particles | |
WO2021049631A1 (en) | Liquid leakage inhibitor used in absorbent containing water absorbent resin particles, and water absorbent resin particles | |
JP7194197B2 (en) | Absorbent bodies and absorbent articles | |
EP3936537A1 (en) | Water-absorbing resin particles and method for producing same | |
EP3960792A1 (en) | Water-absorbent resin particles | |
US20220152581A1 (en) | Water absorbent resin particles, absorber and absorbent article | |
WO2020122211A1 (en) | Water-absorbent resin particles | |
US20220023113A1 (en) | Absorption body and absorptive article | |
WO2021049488A1 (en) | Water-absorbing resin particles and absorbent article | |
JPWO2020218168A1 (en) | Water-absorbent resin particles, absorbers and absorbent articles | |
WO2021187501A1 (en) | Water-absorbing sheet and absorbent article | |
WO2021049487A1 (en) | Water absorbent resin particles, absorbent article, and production method for water absorbent resin particles | |
JP6775048B2 (en) | Method for evaluating liquid leakage of water-absorbent resin particles and water-absorbent resin particles, and method for producing water-absorbent resin particles | |
JP6752320B2 (en) | Absorbent article and its manufacturing method | |
WO2022210678A1 (en) | Water-absorbent resin, absorbent body and absorbent article | |
JP6775050B2 (en) | Absorbent article | |
WO2023189672A1 (en) | Water absorbent resin particles and absorbent article | |
WO2021049465A1 (en) | Method for improving amount of water absorption under load, method for manufacturing cross-linked polymer particles, and method for manufacturing water-absorbing resin particles | |
JP7143513B2 (en) | Water-absorbent resin particles, method for producing the same, 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: 20862813 Country of ref document: EP Kind code of ref document: A1 |
|
ENP | Entry into the national phase |
Ref document number: 2021545625 Country of ref document: JP Kind code of ref document: A |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
122 | Ep: pct application non-entry in european phase |
Ref document number: 20862813 Country of ref document: EP Kind code of ref document: A1 |