WO2015030129A1 - ゲル粉砕装置、及びポリアクリル酸(塩)系吸水性樹脂粉末の製造方法、並びに吸水性樹脂粉末 - Google Patents
ゲル粉砕装置、及びポリアクリル酸(塩)系吸水性樹脂粉末の製造方法、並びに吸水性樹脂粉末 Download PDFInfo
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- WO2015030129A1 WO2015030129A1 PCT/JP2014/072620 JP2014072620W WO2015030129A1 WO 2015030129 A1 WO2015030129 A1 WO 2015030129A1 JP 2014072620 W JP2014072620 W JP 2014072620W WO 2015030129 A1 WO2015030129 A1 WO 2015030129A1
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- water
- gel
- absorbent resin
- resin powder
- weight
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- A61F13/53—Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators characterised by the absorbing medium
- A61F2013/530481—Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators characterised by the absorbing medium having superabsorbent materials, i.e. highly absorbent polymer gel materials
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29B—PREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS
- B29B9/00—Making granules
- B29B9/12—Making granules characterised by structure or composition
- B29B2009/125—Micropellets, microgranules, microparticles
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
- B29C48/25—Component parts, details or accessories; Auxiliary operations
- B29C48/36—Means for plasticising or homogenising the moulding material or forcing it through the nozzle or die
- B29C48/50—Details of extruders
- B29C48/68—Barrels or cylinders
- B29C48/681—Barrels or cylinders for single screws
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
- B29C48/25—Component parts, details or accessories; Auxiliary operations
- B29C48/36—Means for plasticising or homogenising the moulding material or forcing it through the nozzle or die
- B29C48/50—Details of extruders
- B29C48/68—Barrels or cylinders
- B29C48/685—Barrels or cylinders characterised by their inner surfaces, e.g. having grooves, projections or threads
- B29C48/687—Barrels or cylinders characterised by their inner surfaces, e.g. having grooves, projections or threads having projections with a short length in the barrel direction, e.g. pins
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
- B29K2033/00—Use of polymers of unsaturated acids or derivatives thereof as moulding material
- B29K2033/04—Polymers of esters
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
- B29K2105/00—Condition, form or state of moulded material or of the material to be shaped
- B29K2105/0058—Liquid or visquous
- B29K2105/0061—Gel or sol
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J2300/00—Characterised by the use of unspecified polymers
- C08J2300/14—Water soluble or water swellable polymers, e.g. aqueous gels
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J2333/00—Characterised by the use of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides, or nitriles thereof; Derivatives of such polymers
- C08J2333/02—Homopolymers or copolymers of acids; Metal or ammonium salts thereof
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J2333/00—Characterised by the use of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides, or nitriles thereof; Derivatives of such polymers
- C08J2333/04—Characterised by the use of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides, or nitriles thereof; Derivatives of such polymers esters
- C08J2333/06—Characterised by the use of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides, or nitriles thereof; Derivatives of such polymers esters of esters containing only carbon, hydrogen, and oxygen, the oxygen atom being present only as part of the carboxyl radical
- C08J2333/08—Homopolymers or copolymers of acrylic acid esters
Definitions
- the present invention relates to a gel grinding device, a method for producing a polyacrylic acid (salt) water-absorbing resin powder, and a water-absorbing resin powder.
- Water-absorbing resin (SAP / Super Absorbent Polymer) is a water-swellable, water-insoluble polymer gelling agent. Absorbent articles such as paper diapers and sanitary napkins. As a material etc., it is frequently used mainly for disposable use.
- a water absorbent resin many monomers have been proposed as a hydrophilic polymer or a raw material for the water absorbent resin. Among them, in particular, polyacrylic acid (salt) water-absorbing resin using acrylic acid and its salt as a monomer, or a combination thereof, is most commonly used industrially from the viewpoint of its high water absorption performance. .
- water-absorbent resins With the improvement in performance of paper diapers, which are the main use of water-absorbent resins, many functions (physical properties) are required for water-absorbent resins.
- specific examples of physical properties of the water-absorbing resin are not limited to high water absorption capacity, but include gel strength, water-soluble content, water absorption speed, water absorption capacity under pressure, liquid permeability, particle size distribution, urine resistance, Examples include antibacterial properties, impact resistance (damage resistance), powder flowability, deodorization, coloration resistance (whiteness), and low dust.
- the water absorption capacity under pressure is considered to be one of the more important physical properties.
- liquid permeability and water absorption speed are considered to be important basic physical properties of the water absorbent resin. For this reason, techniques for improving the water absorption capacity, liquid permeability and water absorption speed under pressure of the water absorbent resin have been studied.
- the amount of water-absorbent resin used in paper diapers increases (for example, the content of the water-absorbent resin powder is 40% by mass or more with respect to the total mass of the water-absorbent resin powder and the fibrous material). ) And as paper diapers are used in various climatic regions, the heat-retaining properties of the water-absorbent resin have attracted attention.
- Patent Document 1 discusses a method for producing a polyacrylic acid (salt) water-absorbent resin powder having improved both liquid permeability and water absorption speed. Specifically, Patent Document 1 discusses controlling the gel pulverization process, the drying process, and the surface treatment process in the production process of the polyacrylic acid (salt) -based water absorbent resin powder.
- the water-absorbent resin further improvement in physical properties is required for the water-absorbent resin.
- it is necessary to improve the water absorption capacity under pressure.
- the return of liquid also called “Rewet”
- a water-absorbing resin that is useful can be provided.
- the present inventors have intensively studied, and as a result, have found that the physical properties of the water-absorbent resin are dramatically improved by controlling the shape of the water-absorbent resin particles more precisely. Further studies have been made, and the shape of a production apparatus capable of controlling the water-absorbent resin to an optimum shape has been found, and the present invention has been completed. That is, the present invention includes the following inventions.
- a gel crusher used for producing a water-absorbent resin comprising a screw, a supply port, an extrusion port, a perforated plate, and a barrel, wherein the screw is a rotating shaft that is the center of rotation and the above-mentioned
- the rotary shaft is provided with a spirally provided flight, and the cross-sectional area of the rotary shaft obtained when the screw is cut perpendicular to the extrusion direction of the gel of the water absorbent resin is B, the rotation of the flight
- the screw is Gel crusher characterized by satisfying either of the following (1) or (2): (1) 0.215 ⁇ B / A ⁇ 0.630 (2) 0.034 ⁇ F / N ⁇ 0.20.
- a polyacrylic acid including a polymerization step of an aqueous solution of an acrylic acid (salt) monomer, a gel pulverization step of a hydrogel crosslinked polymer during or after polymerization, and a drying step after gel pulverization) Salt
- water-absorbent resin powder wherein the solid content of the resin is 10 to 80 wt.%
- the gel crushing step using the gel crusher according to any one of [1] to [8].
- % Water-containing gel-like crosslinked polymer a method for producing a water-absorbent resin powder.
- the amount of hydrogel treated per hour in the gel grinding device is T [g / hr], and the amount of treatment per unit time of the gel grinding device is the treatment inner diameter ratio T / N 3 [g / hr / when a mm 3], T / N 3, characterized in that 0.05 to 2.0 the method of manufacturing a water-absorbent resin powder according to [9].
- the water-containing gel pulverized in the above-described gel pulverization step is a ventilation belt type dryer, the drying temperature is 150 to 250 ° C., and the hot air velocity is 0.8 to 2.5 [m] in the vertical direction (vertical direction). / S], the method for producing a water-absorbent resin powder according to [9] or [10].
- the present inventors have intensively studied, and as a result, by making the thermal conductivity of the water-absorbent resin powder below a specific value, an absorbent body with low heat loss and excellent heat retention can be obtained. I found out that That is, the present invention includes the following inventions.
- the water-absorbent resin powder has a mass average particle diameter D50 of 350 to 460 ⁇ m and a logarithmic standard deviation of the particle size distribution of 0.25 to 0.45 [1-1. ]
- the water-absorbent resin powder according to any one of [1-4].
- the ratio of particles that pass through a sieve having a mesh size of 710 ⁇ m and that does not pass through a sieve having a mesh size of 500 ⁇ m is 36% by mass or less, which is included in the water-absorbent resin powder.
- An absorbent body comprising the water-absorbent resin powder described in [1-1] to [1-7] and a fibrous material.
- the gel crusher according to the present invention it is possible to produce a water-absorbing resin having an increased water absorption capacity under pressure, and thus hygiene such as paper diapers, sanitary napkins and medical blood-collecting agents having more excellent physical properties. There is an effect that supplies can be provided.
- Rewet liquid return
- FIG. 1 is a schematic cross-sectional view showing an overall configuration of a gel crusher according to the present invention. It is general
- FIG. 3 is a cross-sectional view of the screw and barrel cut in a direction perpendicular to the extrusion direction of the hydrous gel, with the screw cut along the X-X ′ plane in FIG. 2. It is a schematic sectional drawing explaining the internal diameter N of a barrel, the flight width F, and the pitch length P.
- FIG. It is the schematic of the apparatus used for the measurement of the apparent loss calorie
- the gel pulverization apparatus for producing the water absorbent resin according to the present invention the method for producing the water absorbent resin using the gel pulverization apparatus, and the water absorbent resin obtained by the production method will be described in detail.
- the scope of the present invention is not limited to these explanations, and other than the following examples, the scope of the present invention can be changed and implemented as appropriate without departing from the spirit of the present invention.
- the present invention is not limited to the following embodiments, and various modifications can be made within the scope shown in the claims, and technical means disclosed in different embodiments can be appropriately combined.
- the obtained embodiment is also included in the technical scope of the present invention.
- weight and “mass” are treated as synonyms.
- Water absorbent resin The “water-absorbing resin” in the present invention means a water-swellable water-insoluble polymer gelling agent.
- water swellability means that the CRC (water absorption capacity under no pressure) specified by ERT442.2-02 is 5 [g / g] or more
- water insolubility It means that Ext (water-soluble content) specified by ERT470.2-02 is 0 to 50% by weight.
- the water-absorbent resin can be appropriately designed according to its use and is not particularly limited, but may be a hydrophilic cross-linked polymer obtained by cross-linking an unsaturated monomer having a carboxyl group. preferable. Further, the total amount (100% by weight) is not limited to the form of a polymer, and may be a composition containing a surface-crosslinked one, an additive and the like within a range that maintains the above performance.
- the “water-absorbing resin” in the present invention is a resin obtained by pulverizing the hydrophilic crosslinked polymer, and for convenience, in this specification, the water-absorbing resin before surface treatment or surface crosslinking is referred to as “water-absorbent resin particles” and the water-absorbent resin after surface treatment or surface crosslinking are referred to as “water-absorbent resin powder”. Furthermore, even if the water-absorbing resin is different in shape obtained in each step (the shape includes, for example, a sheet shape, a fiber shape, a film shape, a gel shape, etc.), the water-absorbing resin composition containing an additive or the like Even a product is collectively referred to as “water-absorbing resin” in the present specification.
- Polyacrylic acid (salt) “Polyacrylic acid (salt)” “Polyacrylic acid (salt)” in the present invention includes a graft component as necessary, and as a repeating unit, acrylic acid and its salt (in this specification, both are collectively referred to as “acrylic acid (salt)”. Or a combination thereof as a main component.
- the “polyacrylic acid (salt)” in the present invention is essentially 50 to 100 mol% of acrylic acid (salt) out of the total monomers (excluding the internal crosslinking agent) used in the polymerization,
- the polymer preferably contains 70 to 100 mol%, more preferably 90 to 100 mol%, particularly preferably substantially 100 mol%.
- polyacrylic acid salt
- the main component of the water-soluble salt is preferably a monovalent salt, an alkali metal salt.
- an ammonium salt is more preferable, an alkali metal salt is further preferable, and a sodium salt is particularly preferable.
- EDANA European Disposables and Nonwovens Associations
- ERT a standard for measuring water-absorbent resin (EDANA Recommended Test Methods), which is a European standard (almost a global standard). Abbreviation. In the present invention, unless otherwise specified, measurement is performed in accordance with the ERT original (known document: revised in 2002).
- CRC is an abbreviation for Centrifuge Retention Capacity, which means water absorption capacity without pressure (referred to as “water absorption capacity” in this specification). Specifically, “CRC” means that 0.200 g of the water-absorbent resin in the non-woven bag was freely swollen for 30 minutes in a large excess of 0.9 wt% sodium chloride aqueous solution and drained using a centrifuge. It refers to the water absorption capacity (unit: [g / g]) of the subsequent water absorbent resin.
- the CRC of the hydrogel crosslinked polymer (referred to herein as “gel CRC”) is measured by changing the sample to 0.4 g and the free swelling time to 24 hours.
- the weight of the water-absorbing resin is calculated using a value obtained by multiplying the weight of the sample by the resin solid content (% by weight) of the water-containing gel-like crosslinked polymer and multiplying by 0.01.
- AAP is an abbreviation for Absorption Against Pressure, which means water absorption magnification under pressure. Specifically, “AAP” means that 0.900 g of a water-absorbing resin is 2.06 kPa (0.3 psi, 21 [g / cm 2 ]) for 0.9 hour with respect to a 0.9 wt% sodium chloride aqueous solution. The water absorption ratio (unit: [g / g]) of the water absorbent resin after swelling under load. In ERT442.2-02, “Absorption Under Pressure” is indicated, but the content is substantially the same. In the measurement described in this specification, the load condition is changed to 4.83 kPa (0.7 psi, 49 [g / cm 2 ]).
- Ext is an abbreviation for Extractable and means a water-soluble component (water-soluble component amount). Specifically, “Ext” refers to the amount of dissolved polymer (unit: wt%) after adding 1.000 g of water-absorbing resin to 200 mL of 0.9 wt% sodium chloride aqueous solution and stirring for 16 hours. The amount of the dissolved polymer is measured using pH titration.
- the water-soluble content of the hydrogel crosslinked polymer (referred to herein as “gel Ext”) is measured by changing the sample to 5.0 g and the stirring time to 24 hours.
- the weight of the water-absorbing resin is calculated using a value obtained by multiplying the weight of the sample by the resin solid content (% by weight) of the water-containing gel-like crosslinked polymer and multiplying by 0.01.
- PSD is an abbreviation for Particle Size Distribution, and means a particle size distribution measured by sieve classification.
- the weight average particle diameter (D50) and the particle diameter distribution width are the same as those described in “(1) Average Particle Diameter and Distribution of Particle Diameter” described on page 7 lines 25 to 43 of the specification of European Patent No. 0349240. Measure by method. A method for measuring PSD of the hydrogel crosslinked polymer will be described later.
- European Patent No. 1594556 is an abbreviation for Particle Size Distribution, and means a particle size distribution measured by sieve classification.
- the weight average particle diameter (D50) and the particle diameter distribution width are the same as those described in “(1) Average Particle Diameter and Distribution of Particle Diameter” described on page 7 lines 25 to 43 of the
- “Residual Monomers” (ERT410.2-02) “Residual Monomers” means the amount of monomer (monomer) remaining in the water-absorbent resin (referred to herein as “residual monomer”). Specifically, “Residual Monomers” refers to dissolved monomers after adding 1.0 g of water-absorbing resin to 200 mL of 0.9 wt% sodium chloride aqueous solution and stirring at 500 rpm for 1 hour using a 35 mm stirrer chip. The amount (unit: ppm). The amount of dissolved monomer is measured using HPLC (high performance liquid chromatography).
- the residual monomer of the hydrogel crosslinked polymer was measured by changing the sample to 2 g and the stirring time to 3 hours, respectively, and the obtained measured value was the weight per resin solid content of the hydrogel crosslinked polymer.
- “Moisture Content” (ERT430.2-02) “Moisture Content” means the water content of the water-absorbent resin. Specifically, “Moisture Content” is a value (unit:% by weight) calculated from a loss on drying when 1 g of the water-absorbent resin is dried at 105 ° C. for 3 hours. In the present invention, the drying temperature is changed to 180 ° C., the measurement is performed 5 times per sample, and the average value is adopted. The water content of the hydrogel crosslinked polymer is measured by changing the sample to 2 g, the drying temperature to 180 ° C., and the drying time to 16 hours. Further, the value calculated by ⁇ 100-water content (% by weight) ⁇ is “resin solid content” in the present invention, and can be applied to both the water-absorbent resin and the water-containing gel-like crosslinked polymer.
- Density (ERT460.2-02) “Density” means the bulk specific gravity of the water-absorbent resin. Specifically, “Density” refers to the weight of the water absorbent resin (unit; [100%] when 100 g of the water absorbent resin is put into an EDANA-specified apparatus and the 100 mL container is filled with the water absorbent resin by free fall. g / mL]).
- Flow Rate means the flow rate of the water absorbent resin. Specifically, “Flow Rate” means that when 100 g of water-absorbing resin is put into an EDANA-specified apparatus and the water-absorbing resin is discharged from the lowermost outlet of the apparatus, the time required for the discharge (unit: sec) Say.
- Liquid permeability refers to the fluidity of a liquid passing between particles of a swollen gel under load or no load.
- SFC Seline Flow Conductivity / saline flow conductivity
- GBP Gel Bed Permeability / gel bed permeability
- SFC saline flow inductive
- GFP liquid permeability of a 0.69 wt% sodium chloride aqueous solution with respect to the water absorbent resin under load or free expansion, and is disclosed in International Publication No. 2005/016393. It is measured according to the test method.
- FSR Free Swell Rate
- FSR means a water absorption rate (free swelling rate).
- FSR refers to the rate (unit: [g / (g ⁇ s)]) at which 1 g of the water-absorbent resin absorbs 20 g of 0.9 wt% sodium chloride aqueous solution.
- the “gel pulverization” in the present invention refers to a hydrogel crosslinked polymer obtained in a polymerization step (preferably aqueous solution polymerization, non-stirred aqueous solution polymerization (stationary aqueous solution polymerization), particularly preferably belt polymerization). This means an operation for reducing the size of the polymer and preparing it in a desired shape using the gel pulverizer.
- a polymerization step preferably aqueous solution polymerization, non-stirred aqueous solution polymerization (stationary aqueous solution polymerization), particularly preferably belt polymerization.
- the hydrogel crosslinked polymer obtained in the polymerization step is subjected to gel pulverization using the gel pulverizer of the present invention, and the weight average particle diameter (D50) is 300 to 3,000 ⁇ m, more preferably The hydrogel crosslinked polymer is gel-pulverized so that the weight average particle diameter (D50) is 350 to 2,000 ⁇ m and the logarithmic standard deviation ( ⁇ ) of the particle size distribution is preferably 0.2 to 1.0.
- the shape of the hydrated gel-like crosslinked polymer obtained may differ depending on the type of the polymerization machine.
- the gel pulverization may be performed by the gel pulverizer of the present invention after the polymerization.
- weight-average molecular weight of water-soluble matter means GPC (gel permeation chromatography) for the weight-average molecular weight of a component (water-soluble component) that dissolves when a water-absorbent resin is added to an aqueous solvent.
- GPC gel permeation chromatography
- the weight-average molecular weight of the water-soluble gel-crosslinked polymer was measured by measuring 5.0 g of the sample having a particle size of 5 mm or less, and further 1 to 3 mm, and stirring time of 24 hours. Change and do.
- GGE “Gel grinding energy”
- GGE “Gel grinding energy”
- the “gel grinding energy” in the present invention means the mechanical energy per unit weight (unit weight of the hydrogel crosslinked polymer) required by the gel grinding device when gelling the hydrogel crosslinked polymer. It does not include the energy to heat and cool the jacket or the energy of water and steam to be charged. “Gel grinding energy” is abbreviated as “GGE” from “Gel Grinding Energy” in English.
- the GGE has the following formula (1) when the gel crusher is driven by three-phase AC power.
- GGE [J / g] ⁇ 3 ⁇ voltage ⁇ current ⁇ power factor ⁇ motor efficiency ⁇ / ⁇ Weight of hydrogel cross-linked polymer charged into gel grinder per second ⁇ ...
- the above “power factor” and “motor efficiency” are values unique to the apparatus that vary depending on the operating conditions of the gel crushing apparatus, and take values from 0 to 1.
- the GGE can be calculated by changing “ ⁇ 3” in the above formula (1) to “1”.
- the unit of voltage is [V]
- the unit of current is [A]
- the unit of weight of the hydrogel crosslinked polymer is [g / s].
- pulverization of a hydrogel crosslinked polymer can also be performed using a some gel grinding
- the gel grinding device calculates the gel grinding energy by subtracting the current value during idle operation.
- Formula (2) Is calculated by
- pulverization energy calculated by the said Formula (2) is described with GGE (2).
- X to Y indicating a range means “X or more and Y or less”.
- T (ton) which is a unit of weight means “Metric ton”, and unless otherwise noted, “ppm” means “ppm by weight”.
- Weight” and “mass”, “wt%” and “mass%”, “part by weight” and “part by mass” are treated as synonyms.
- ⁇ acid (salt) means “ ⁇ acid and / or salt thereof”
- (meth) acryl means “acryl and / or methacryl”.
- the “main component” means that 51% or more of the whole is occupied.
- Gel pulverizing apparatus subdivides the water-containing gel-like crosslinked polymer during or after polymerization, and forms a desired shape of water-containing gel-like crosslinked polymer (in the present specification, “particle It is an apparatus used to obtain a “form hydrous gel”.
- Patent Document 1 Conventional gel crushing is an operation to increase the surface area by reducing the size by applying shearing and compressive force for the purpose of facilitating drying, so that the hydrogel is not kneaded in the means of crushing.
- Those that can be cut or crushed were considered preferable (see prior art documents described in Patent Document 1 (for example, US Pat. Nos. 7,694,900, 6,565,768, and 6,140,395)) .
- Patent Document 1 specific gel grinding conditions and drying conditions in gel grinding energy or water-soluble weight-average molecular weight, or specific gel weight-average particle diameter and particle size distribution gel are dried. It has succeeded in improving liquid permeability and water absorption speed by drying under conditions.
- the inventors obtained a gel pulverization process, which is one of the water-absorbent resin production processes, by further pulverizing the hydrogel so as to knead it by using a specific device shape. It has been found that the water absorption capacity under pressure of the water-absorbent resin is improved. Furthermore, it has been found that it is possible to achieve high physical properties with respect to liquid permeability (and water absorption speed). Details of the gel crusher according to the present invention will be described below.
- FIG. 1 is a schematic cross-sectional view showing the overall configuration of a gel crusher 100 according to the present invention.
- the gel crusher 100 is an apparatus used for obtaining a particulate hydrous gel having a desired shape.
- the gel pulverization apparatus 100 is an apparatus used in a gel pulverization process performed between a polymerization process and a drying process, in particular, in the production of a water absorbent resin.
- the gel crusher 100 includes a screw 11, a perforated plate 12, a barrel 13, a supply port 14, a hopper 15, an extrusion port 16, a rotary blade 17, a ring 18, a reverse prevention member 19, a table 20, and a motor. And a reduction gear 21 and the like.
- a screw 11 is provided inside a cylindrical barrel 13.
- One end of the barrel 13 is provided with an extrusion port 16 for extruding the hydrogel and pulverizing the gel, and a porous plate 12 is installed in front of the extrusion port 16.
- the other end is provided with a motor and a speed reducer 21 for rotating the screw 11.
- a drive system and the like are arranged below the barrel 13, there is a table 20, whereby a screw type extruder can be stably installed.
- a supply port 14 for supplying a hydrogel
- a hopper 15 is provided to facilitate the supply of the hydrogel.
- the gel crusher 100 is preferably maintained in durability even when used for 8000 hours or more per year. Therefore, it is preferable that the connection part of each member is attached so that it may not come off easily even if power is applied.
- FIG. 2 is a schematic cross-sectional view showing the vicinity of the extrusion port 16 of the gel crusher 100.
- the screw 11 mainly includes a rotating shaft 22 and a flight part 23.
- the flight part 23 is mounted in a spiral shape around the rotation shaft 22.
- the number of turns of the flight part 23 around the rotating shaft 22 refers to the number of windings from the end of the rotating shaft 22 to the other end.
- the number of turns of the flight part is not particularly limited, but is preferably 3 or more, and particularly preferably 4 or more.
- the flight part 23 may be a single helix, a double helix, or a triple helix, and the number of the flight parts 23 mounted on the rotating shaft 22 is not particularly limited.
- the flight part 23 wound around the rotating shaft 22 is wound around the rotating shaft 22 in a direction opposite to the direction in which the rotating shaft 22 rotates. That is, in FIG. 1, when the gel crusher according to the present invention is viewed from the motor / reduction gear 21 toward the extrusion port 16 and the rotation of the rotary shaft 22 is right rotation, the flight The part 23 is wound around the rotating shaft 22 by left rotation.
- the shape or size of the barrel 13 is not particularly limited as long as it has a cylindrical inner surface corresponding to the shape of the screw 11.
- the barrel 13 may or may not be equipped with a reverse-turn preventing member 19.
- the reversion preventing member 19 it is not particularly limited as long as it is a structure that can prevent the water-containing gel from reversing, and the inner wall of the barrel 13 has a spiral, concentric strip-like protrusion, Alternatively, it may be a straight, granular, spherical, or angular protrusion parallel to the screw 11.
- the reversal prevention member 19 is formed in a spiral shape inside the barrel 13, the number wound from the supply port 14 to the extrusion port 16 is referred to as “barrel multiplier” in the present specification.
- the height protruding from the inner surface of the barrel 13 is referred to as “barrel peak height (YH)”, and the width in the direction perpendicular to the extending direction of the surface of the reverse return preventing member 19 closest to the screw 11 is defined as “barrel height”. It is called “Yama width (YF)”.
- YH barrel peak height
- YF Yama width
- the reverse prevention member 19 is spirally formed inside the barrel 13, it is formed in the barrel 13 in the same direction as the rotation shaft 22 rotates. That is, in FIG. 1, when the direction of the extrusion port 16 is viewed from the motor and the speed reducer 21, and when the rotation of the rotating shaft 22 is a right rotation, the reverse prevention member 19 is formed in the barrel by a right rotation. Is done.
- FIG. 3 is a cross-sectional view of the screw 11 and the barrel 13 cut in the direction perpendicular to the extrusion direction of the hydrogel, with the screw cut along the X-X ′ plane of FIG.
- the maximum inner diameter at which the anti-reverse member 19 inside the barrel 13 does not contact the screw 11 is N (also referred to as “inner diameter N” in this specification), and the area of the surface where the inner diameter is N.
- A also referred to as “cross-sectional area A of the rotating part of the flight”, “cross-sectional area A” in the present specification
- cross-sectional area B it is also referred to as “cross-sectional area B”.
- the diameter of the rotating shaft 22 is appropriately set depending on the amount of the hydrogel to be processed, but is preferably in the range of 20 to 600 [mm], and more preferably in the range of 80 to 400 [mm].
- screw cross-sectional area ratio refers to the ratio of the cross-sectional area B to the cross-sectional area A and is expressed as “B / A”.
- the screw cross-sectional area ratio B / A ranges from 0.215 to 0.630, preferably from 0.22 to 0.630, and more preferably from 0.260 to 0.630. 0.630, more preferably 0.300 to 0.630, particularly preferably 0.370 to 0.630, particularly preferably 0.430 to 0.630, and most preferably 0. .540 to 0.630.
- the value of B / A is smaller than 0.22, there is a fear that the target performance cannot be obtained because the space is large and the gel discharged without being sufficiently sheared may not be obtained. If the value is larger than 0.630, the space portion is too narrow, so that the gel may be clogged or excessively sheared and the target performance may not be obtained.
- the value of B / A is within the above range, the water absorption capacity of the water absorbent resin under pressure is preferably improved.
- the clearance between the reversing prevention member 19 inside the barrel 13 and the flight part 23 is denoted by ⁇ (also referred to as “clearance ⁇ ” in the present specification).
- the value of the clearance ⁇ ( ⁇ / N) with respect to the inner diameter N is preferably 0.001 to 0.043, more preferably 0.001 or more and less than 0.043, and further preferably 0.005 to 0.036, most preferably 0.010 to 0.03.
- ⁇ / N is smaller than 0.001
- Is larger than 0.06 the gap between the screw and the barrel projection is too large, so that sufficient shear is not applied to the gel and the desired performance may not be obtained.
- ⁇ / N When the value of ⁇ / N is in the above range, it is preferable because the water absorption magnification under pressure of the water absorbent resin is improved. Further, it is preferable because the effect of further reducing the thermal conductivity of the water-absorbing resin obtained can be achieved.
- FIG. 4 is a schematic cross-sectional view illustrating the inner diameter N, the flight width F, and the pitch length P of the screw.
- the width of the upper surface of the flight part 23 not in contact with the rotating shaft 22 in the direction perpendicular to the extending direction of the flight part is F (also referred to as “flight width F” in the present specification).
- the distance connecting the centers of the flight widths F is P (also referred to as “pitch length P” in this specification).
- the value (F / N) of the flight width F with respect to the inner diameter N is 0.03 to 0.20, preferably larger than 0.034. It is 0.20 or less, more preferably 0.05 to 0.15, still more preferably 0.07 to 0.13.
- the F / N value is smaller than 0.03, the area to be kneaded between the screw and the barrel projection is small, and the target performance may not be obtained because sufficient shear is not applied to the gel.
- the F / N value is greater than 0.20, the area to be kneaded between the screw and the barrel projection is too large, and excessive shear is applied to the gel, and the desired performance may not be obtained. There is.
- the F / N value is within the above range, the water absorption capacity of the water absorbent resin under pressure is improved, which is preferable. Further, it is preferable because the effect of further reducing the thermal conductivity of the water-absorbing resin obtained can be achieved.
- the value (P / N) of the pitch length P with respect to the inner diameter N is preferably any P / N between the first roll and the second roll from the extrusion port toward the supply port. It is 0.15 to 0.68, more preferably 0.20 to 0.50, and most preferably 0.25 to 0.40.
- the value of P / N is smaller than 0.15, the space portion is too narrow, and there is a risk that the gel may be clogged or excessive shearing may be applied to the gel, so that the intended performance cannot be obtained.
- the value of N is larger than 0.68, since the space is large, the gel discharged without being sufficiently sheared may increase, and the target performance may not be obtained.
- any pitch length preferably satisfies the above range, and any pitch length from the first to second rolls satisfies the above range. More preferably, it is most preferable that the pitch length of the first roll satisfies the above range.
- the gel crusher according to the present invention In order to improve the physical properties of the water-absorbent resin obtained using the gel crusher according to the present invention, it is sufficient that at least one of the above-described B / A and F / N satisfies the above range. And F / N most preferably satisfy the above range.
- the gel crusher according to the present invention when at least one of B / A and F / N satisfies the above range, there is an effect that it is possible to manufacture a water-absorbing resin with improved water absorption capacity under pressure. In addition, there is an effect that the thermal conductivity of the water-absorbing resin obtained can be reduced.
- the material of the screw 11 and the barrel 13 in the present invention is not particularly limited, but stainless steel is preferable from the viewpoint of durability and a method of applying a shearing force to the water-containing gel. Specifically, austenitic stainless steel is preferable, and SUS304 is more preferable.
- the perforated plate 12 in the present invention is a member provided in an outlet portion where the hydrogel in the barrel 13 is extruded in the gel crusher according to the present invention.
- the thickness, pore diameter, or open area ratio of the porous plate 12 can be appropriately selected depending on the amount of treatment per unit time of the gel crushing device or the shape of the hydrogel, and is not particularly limited.
- the “die thickness” is preferably 3.5 to 40 mm, more preferably 8 to 30 mm, and most preferably 10 to 25 mm.
- the hole diameter of the perforated plate (also referred to as “die hole diameter” in the present specification) is preferably 3.2 to 30 mm, and more preferably 7.5 to 25 mm.
- the aperture ratio (also referred to as “die aperture ratio” in this specification) of the perforated plate is preferably 20 to 80%, more preferably 30 to 55%.
- the simple average value of the hole diameters of the perforated plates is used as the pore size of the perforated plate in the gel crusher.
- the shape of the hole is preferably a circle, but is not particularly limited. In the case of a shape other than a circle (for example, a quadrangle, an ellipse, a slit, etc.), the hole area is converted into a circle with a hole diameter ( mm).
- the die thickness is thinner than 3.5 mm
- the die hole diameter is larger than 30 mm
- the die opening rate is larger than 80%
- the water-containing gel may be excessively sheared / compressed, and the physical properties of the water-absorbent resin may be deteriorated.
- the material (metal) of the porous plate 12 in the present invention is preferably a material (metal) different from the material of the screw 11 and the barrel 13.
- the material of the perforated plate 12 is the same as that of the screw 11 and the barrel 13, there is a risk of damage to the apparatus due to seizure or the like.
- the material of the porous plate 12 is preferably a metal whose hardness can be increased by quenching (heat treatment).
- the gel crusher according to the present invention may include a bearing portion.
- the “bearing portion” refers to a member provided between a die plate and a rotating shaft.
- the material of the portion where the rotating shaft 22 and the bearing portion come into contact is preferably different from the material of the rotating shaft and the bearing portion, and more preferably a metal of a different material.
- the material of the rotating shaft 22 and the bearing portion is the same as that of the portion where the rotating shaft 22 and the bearing portion are in contact with each other, there is a risk of damage to the device due to seizure or the like, and mixing of metal powder into the product.
- the rotational speed of the rotating shaft 22 and the outer peripheral speed of the flight part 23 The rotational speed of the rotary shaft 22 in the present invention cannot be generally defined because the outer peripheral speed of the rotary blade changes depending on the inner diameter of the barrel 13.
- the rotational speed of the rotary shaft 22 is preferably 60 to 500 rpm, 80 ⁇ 400 rpm is more preferred, and 100 ⁇ 200 rpm is even more preferred.
- the rotation speed of the rotating shaft 22 is less than 60 rpm, there is a possibility that the shear / compression force necessary for gel crushing cannot be obtained.
- the shearing / compressing force applied to the water-containing gel becomes excessive, resulting in a decrease in physical properties of the resulting water-absorbent resin, or a load applied to the gel crusher according to the present invention. May grow and be damaged.
- the temperature during use of the gel crusher 100 in the present invention is preferably 40 to 120 ° C., more preferably 60 to 100 ° C., in order to prevent adhesion of the hydrogel.
- the gel crusher in this invention has a heating apparatus, a heat retention apparatus, etc.
- the temperature of the hydrogel before gel pulverization supplied to the gel pulverizer according to the present invention (also referred to herein as “gel temperature”) is preferably 40 to 120 ° C. from the viewpoint of particle size control and physical properties. 60 to 120 ° C is more preferable, 60 to 110 ° C is more preferable, and 65 to 110 ° C is particularly preferable. When the gel temperature is less than 40 ° C., the hardness and elasticity increase due to the characteristics of the hydrogel, and therefore it may be difficult to control the particle shape or particle size distribution during gel pulverization.
- the said gel temperature exceeds 120 degreeC, the softness of a water-containing gel increases and there exists a possibility that control of a particle shape or a particle size distribution may become difficult.
- the gel temperature can be appropriately controlled by the polymerization temperature or the post-polymerization heating, heat retention or cooling.
- the processing amount per unit time of the gel crusher according to the present invention is a value depending on the inner diameter N, and a suitable range varies.
- the throughput of the hydrogel per hour of the gel crusher according to the present invention is T [g / hr] and the value obtained by cubeing the inner diameter N is N 3 [mm 3 ]
- the gel crush according to the present invention can be represented by a processing amount inner diameter ratio T / N 3 [g / hr / mm 3 ].
- the upper limit of the inner diameter ratio T / N 3 [g / hr / mm 3 ] is preferably 2.0 or less, more preferably 1.5 or less, and 1.0 or less. Most preferred.
- the lower limit of the above-mentioned processing amount inner diameter ratio T / N 3 [g / hr / mm 3 ] is preferably 0.05 or more, more preferably 0.10 or more, and 0.15 or more. Most preferred.
- the processing amount inner diameter ratio T / N 3 [g / hr / mm 3 ] is less than 0.05, the processing amount is too small, so that the hydrogel stays in the gel crusher and is excessive. May cause excessive shearing or gel degradation.
- the gel can be crushed by adding water to the hydrous gel.
- the “water” added in the present invention may include any form of solid, liquid, and gas. From the viewpoint of handleability, a liquid or gas form or a mixed form of liquid and gas is preferable.
- the method of adding water or the timing of adding water is not particularly limited, but it is sufficient that water is supplied into the apparatus while the hydrogel is staying in the gel crushing apparatus 100.
- a hydrogel to which water has been added in advance may be charged into the gel crusher 100.
- the addition of water may be performed by adding “water” alone, other additives (for example, a surfactant, a neutralizing base, a crosslinking agent, an inorganic salt, etc.) or a solvent other than water. You may add together.
- the water content is preferably 90 to 100% by weight, more preferably 99 to 100% by weight, and still more preferably 100% by weight. .
- the amount of water supplied is preferably 0 to 4 parts by weight, more preferably 0 to 2 parts by weight with respect to 100 parts by weight of the hydrogel.
- the supply amount of water exceeds 4 parts by weight, there is a risk that problems such as generation of undried material occur during drying.
- the temperature at the time of supply is preferably 10 to 100 ° C, more preferably 40 to 100 ° C.
- the supply temperature is preferably 100 to 220 ° C, more preferably 100 to 160 ° C, and still more preferably 100 to 130 ° C.
- the preparation method is not particularly limited. For example, a method using water vapor generated by heating of a boiler, a gaseous state generated from a water surface by vibrating water with ultrasonic waves. The method of using the water of this is mentioned.
- steam having a pressure higher than atmospheric pressure is preferable, and steam generated in a boiler is more preferable.
- water-containing gel As described above, it is preferable to add water to the water-containing gel and pulverize the gel. However, in addition to water, other additives or neutralizers may be added to the water-containing gel and kneaded to crushed the gel.
- the water-absorbing resin to be produced may be modified. Specifically, during gel pulverization, an aqueous solution containing a basic substance (for example, a 10 to 50% by weight sodium hydroxide aqueous solution) may be added for neutralization, or a water absorbent resin fine powder (0.1 to 30% by weight (based on resin solids)) may be added for fine powder recycling.
- a basic substance for example, a 10 to 50% by weight sodium hydroxide aqueous solution
- a water absorbent resin fine powder 0.1 to 30% by weight (based on resin solids)
- 0.001 to 3% by weight of a polymerization initiator, a reducing agent, and a chelating agent can be added and mixed during gel pulverization to reduce residual monomer, improve coloring, and provide durability. Good.
- GGE Gel grinding energy
- GGE2 Gel grinding energy (2)
- the gel grinding energy (GGE) for grinding the hydrogel is preferably 100 [J / g] or less, more preferably 60 [J / g] or less, and 50 [J / g] as the upper limit. g] The following is more preferable. Moreover, as a lower limit, 15 [J / g] or more is preferable, 18 [J / g] or more is more preferable, and 20 [J / g] or more is still more preferable.
- the gel grinding energy (GGE) for gel grinding of the hydrogel is preferably 15 to 100 [J / g], more preferably 18 to 60 [J / g], and further It is preferably 20 to 50 [J / g]. By controlling the GGE within the above range, gel pulverization can be performed while applying appropriate shear / compression force to the hydrogel.
- the gel pulverization energy (GGE) is defined including the energy during idling of the gel pulverizer.
- the gel crushing energy 2 (GGE2 / Gel Grinding Energy) is controlled within a certain range.
- the gel grinding energy (2) (GGE (2)) for gel grinding of the hydrogel is preferably 40 [J / g] or less, more preferably 32 [J / g] or less. Preferably, 25 [J / g] or less is more preferable.
- the lower limit is preferably 7 [J / g] or more, more preferably 8 [J / g] or more, still more preferably 10 [J / g] or more, and most preferably 12 [J / g] or more.
- the gel grinding energy (2) (GGE (2)) for gel grinding of the hydrogel is 7 to 40 [J / g], preferably 8 to 32 [J / g]. More preferably, it is 10 to 25 [J / g].
- GGE (2) gel grinding energy (2)
- gel pulverization can be performed while applying appropriate shear / compression force to the hydrogel, and the effect of the shape of the gel pulverizer of the present invention can be maximized. be able to.
- the total energy consumed in each apparatus Is gel grinding energy (2) (GGE (2)).
- the gel pulverization apparatus according to the present invention has the above-described configuration, thereby producing an effect that a water-absorbing resin powder having a high water absorption capacity under pressure can be produced. In addition, there is an effect that it is possible to produce a water-absorbing resin having a smaller thermal conductivity.
- the water-absorbent resin powder obtained in the present invention is usually polymerized in an aqueous solution state using a monomer containing acrylic acid (salt) as a main component as a raw material.
- a monomer containing acrylic acid (salt) as a main component is also referred to as “acrylic acid (salt) -based monomer aqueous solution”.
- the monomer (monomer) concentration in the aqueous monomer solution is preferably 10 to 80% by weight, more preferably 20 to 80% by weight, still more preferably 30 to 70% by weight, and particularly preferably 40 to 60% by weight. .
- the acid groups of the polymer is preferably neutralized from the viewpoint of water absorption performance or residual monomer.
- the salt of the neutralized portion is not particularly limited, but from the viewpoint of water absorption performance, monovalent salts selected from alkali metal salts, ammonium salts, or amine salts are preferable, alkali metal salts are more preferable, and sodium salts Alkali metal salts selected from lithium salts or potassium salts are more preferred, and sodium salts are particularly preferred.
- the basic substance used for neutralization is not particularly limited, but alkali metal hydroxide such as sodium hydroxide, potassium hydroxide, or lithium hydroxide, sodium carbonate (hydrogen), potassium carbonate (hydrogen), etc.
- alkali metal hydroxide such as sodium hydroxide, potassium hydroxide, or lithium hydroxide, sodium carbonate (hydrogen), potassium carbonate (hydrogen), etc.
- Monovalent basic substances such as carbonic acid (hydrogen) salts are preferred, and sodium hydroxide is particularly preferred.
- the neutralization can be carried out in each form / state before, during or after polymerization.
- a water-containing gel obtained by polymerizing unneutralized or low-neutralized acrylic acid (for example, 0 to 30 mol%) can be neutralized, particularly neutralized simultaneously with gel pulverization.
- the neutralization rate in the neutralization is not particularly limited, but is preferably 10 to 100 mol%, more preferably 30 to 95 mol%, still more preferably 45 to 90 mol%, as the final water absorbent resin. ⁇ 80 mol% is particularly preferred.
- the neutralization temperature is not particularly limited, but is preferably 10 to 100 ° C, more preferably 30 to 90 ° C.
- the conditions disclosed in EP 574260 are preferably applied to the present invention.
- water-soluble resins or water-absorbent resins such as starch, cellulose, polyvinyl alcohol (PVA), polyacrylic acid (salt), and polyethyleneimine; carbonates, azo
- various foaming agents such as compounds and bubble generating agents
- surfactants such as monomer aqueous solution, hydrous gel, dry polymer or water absorbent resin Can be added.
- the amount of these optional components is preferably 0 to 50% by weight, more preferably 0 to 20% by weight, and still more preferably 0 to 10% by weight based on the monomer. %, Particularly preferably 0 to 3% by weight.
- surfactant or additive 0 to 5% by weight is preferable, and 0 to 1% by weight is more preferable.
- a graft polymer or a water-absorbing resin composition can be obtained by adding the above aqueous resin or water-absorbing resin.
- These starch-acrylic acid polymer, PVA-acrylic acid polymer and the like are also polyacrylic acid in the present invention. Treat as a (salt) water-absorbing resin.
- a chelating agent for the purpose of improving the color stability (color stability when stored for a long time under high temperature and high humidity) or urine resistance (preventing gel deterioration) of the water absorbent resin powder obtained in the present invention, a chelating agent, An ⁇ -hydroxycarboxylic acid compound and an inorganic reducing agent can be used, and it is particularly preferable to use a chelating agent.
- the amount used thereof is preferably 10 to 5,000 ppm, more preferably 10 to 1,000 ppm, still more preferably 50 to 1,000 ppm, and particularly preferably 100 to 1,000 ppm with respect to the water-absorbent resin.
- the chelating agent compounds disclosed in US Pat. No. 6,599,989 or International Publication No. 2008/090961 are applied in the present invention. Among them, it is preferable to use an aminocarboxylic acid metal chelating agent or a polyvalent phosphoric acid compound as the chelating agent.
- acrylic acid (salt) when acrylic acid (salt) is used as a main component, a hydrophilic or hydrophobic unsaturated monomer other than acrylic acid (salt) (referred to as “other monomer” in the present specification). ) May be used in combination.
- Examples of such other monomers include, but are not particularly limited to, for example, methacrylic acid, (anhydrous) maleic acid, 2- (meth) acrylamide-2-methylpropanesulfonic acid, (meth) acryloxyalkanesulfonic acid, N-vinyl-2-pyrrolidone, N-vinylacetamide, (meth) acrylamide, N-isopropyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, 2-hydroxyethyl (meth) acrylate, methoxypolyethylene glycol (meta ) Acrylate, polyethylene glycol (meth) acrylate, stearyl acrylate, and salts thereof.
- the amount used is appropriately determined within a range not impairing the water absorption performance of the resulting water-absorbent resin powder, and is not particularly limited. 50 mol% is preferable, 0 to 30 mol% is more preferable, and 0 to 10 mol% is still more preferable.
- Internal crosslinking agent In the present invention, it is preferable to use a crosslinking agent (referred to as “internal crosslinking agent” in the present specification) from the viewpoint of the water absorption performance of the water-absorbent resin powder obtained.
- the internal cross-linking agent is not particularly limited, and examples thereof include a polymerizable cross-linking agent with acrylic acid, a reactive cross-linking agent with a carboxyl group, or a cross-linking agent having both of them.
- polymerizable crosslinking agent examples include N, N′-methylenebisacrylamide, (poly) ethylene glycol di (meth) acrylate, (polyoxyethylene) trimethylolpropane tri (meth) acrylate, and poly (meth) allyloxy. Examples thereof include compounds having at least two double bonds having polymerizability in the molecule, such as alkanes.
- the reactive cross-linking agent examples include polyglycidyl ethers such as ethylene glycol diglycidyl ether; covalent cross-linking agents such as polyhydric alcohols such as propanediol, glycerin and sorbitol, and polyvalent metal compounds such as aluminum salts. An ion binding crosslinking agent is mentioned.
- a polymerizable crosslinking agent with acrylic acid is more preferable, and acrylate-based, allyl-based, and acrylamide-based polymerizable crosslinking agents are particularly preferable.
- These internal cross-linking agents may be used alone or in combination of two or more.
- the mixing ratio is preferably 10: 1 to 1:10.
- the amount of the internal crosslinking agent used is preferably 0.001 to 5 mol%, more preferably 0.002 to 2 mol%, and more preferably 0.04 to 2 mol% with respect to the monomer excluding the crosslinking agent from the viewpoint of physical properties.
- 1 mol% is more preferable, 0.06 to 0.5 mol% is particularly preferable, and 0.07 to 0.2 mol% is most preferable.
- the polymerizable cross-linking agent is preferably 0.01 to 1 mol%, more preferably 0.04 to 0.5 mol%, still more preferably 0.06 to 0.1 mol%. use.
- the polymerization initiator used in the present invention is appropriately selected depending on the polymerization form and is not particularly limited, and examples thereof include a photodegradable polymerization initiator, a thermal decomposition polymerization initiator, and a redox polymerization initiator.
- Examples of the photodegradable polymerization initiator include benzoin derivatives, benzyl derivatives, acetophenone derivatives, benzophenone derivatives, and azo compounds.
- Examples of the thermal decomposition polymerization initiator include persulfates such as sodium persulfate, potassium persulfate, and ammonium persulfate; peroxides such as hydrogen peroxide, t-butyl peroxide, and methyl ethyl ketone peroxide; 2 Azo compounds such as 2,2′-azobis (2-amidinopropane) dihydrochloride and 2,2′-azobis [2- (2-imidazolin-2-yl) propane] dihydrochloride.
- redox polymerization initiator examples include a system in which a reducing compound such as L-ascorbic acid or sodium bisulfite is used in combination with the persulfate or peroxide. Furthermore, the combined use of the photodegradable polymerization initiator and the thermal decomposable polymerization initiator is also mentioned as a preferred embodiment.
- the amount of the polymerization initiator used is preferably 0.0001 to 1 mol%, more preferably 0.0005 to 0.5 mol%, based on the monomer.
- the usage-amount of the said polymerization initiator exceeds 1 mol%, there exists a possibility that the color tone of a water absorbing resin may deteriorate.
- the amount of the polymerization initiator used is less than 0.0001 mol%, there is a concern about an increase in residual monomers, which is not preferable.
- the polymerization method may be to obtain a particulate hydrous gel by spray droplet polymerization or reverse phase suspension polymerization.
- aqueous solution polymerization is employed.
- the aqueous solution polymerization may be tank type (silo type) non-stir polymerization, but is preferably kneader polymerization or belt polymerization, more preferably continuous aqueous solution polymerization, further preferably high concentration continuous aqueous solution polymerization, particularly preferably high concentration / high temperature.
- the stirring polymerization means that the water-containing gel (particularly, the water-containing gel having a polymerization rate of 10 mol% or more, more preferably 50 mol% or more) is polymerized while stirring, particularly stirring and fragmenting. Before and after the stirring-free polymerization, the monomer aqueous solution (with a polymerization rate of 0 to less than 10 mol%) may be appropriately stirred.
- continuous aqueous solution polymerization examples include continuous kneader polymerization described in U.S. Pat. Nos. 6,987,171 and 6,710,141, U.S. Pat. Nos. 4,893,999, 6,241,928, U.S. Patent Application Publication No. 2005/215734, and the like. Continuous belt polymerization. By these aqueous solution polymerization, a water-absorbent resin powder can be produced with high productivity.
- the monomer concentration (solid content) is preferably 35% by weight or more, more preferably 40% by weight or more, and even more preferably 45% by weight or more (the upper limit is a saturated concentration).
- the polymerization initiation temperature is preferably 30 ° C. or higher, more preferably 35 ° C. or higher, still more preferably 40 ° C. or higher, and particularly preferably 50 ° C. or higher (the upper limit is the boiling point).
- High concentration, high temperature starting continuous aqueous solution polymerization is a combination of these polymerizations.
- the high concentration / high temperature starting continuous aqueous solution polymerization is disclosed in US Pat. Nos. 6,906,159 and 7,091,253. This polymerization method is preferable because a water-absorbing resin powder having a high whiteness can be obtained and production on an industrial scale is easy.
- the polymerization method in the production method according to the present invention is preferably applied to a production apparatus on a huge scale with a large production amount per line.
- the production amount is preferably 0.5 [t / hr] or more, more preferably 1 [t / hr] or more, further preferably 5 [t / hr] or more, and 10 [t / hr] or more. Particularly preferred.
- the polymerization can be carried out in an air atmosphere, but from the viewpoint of preventing coloring, it can be carried out in an inert gas atmosphere (for example, oxygen concentration of 1% by volume or less) such as water vapor, nitrogen or argon. preferable. Furthermore, it is preferable to perform polymerization after replacing (degassing) the dissolved oxygen in the monomer or the solution containing the monomer with an inert gas (for example, less than 1 [mg / L] oxygen). Even if such deaeration is performed, the stability of the monomer is excellent, gelation before polymerization does not occur, and a water-absorbent resin powder having higher physical properties and higher whiteness can be provided.
- an inert gas atmosphere for example, oxygen concentration of 1% by volume or less
- an inert gas for example, less than 1 [mg / L] oxygen
- the amount of the inert gas used is preferably 0.005 to 0.2% by weight, more preferably 0.01 to 0.1% by weight, more preferably 0.015 to Most preferably, it is 0.5% by weight. Moreover, nitrogen is preferable as the inert gas used.
- a surfactant and / or a dispersant may be used as necessary.
- the surfactant and / or the dispersion liquid it is possible to stably suspend the bubbles in the water absorbent resin during polymerization.
- the water absorbing resin powder which has a desired physical property can be obtained by adjusting suitably the kind or quantity of surfactant and / or a dispersing agent.
- the surfactant is preferably a non-polymer surfactant and the dispersant is preferably a polymer dispersant.
- the surfactant and / or the dispersant is added at a stage before polymerization or before the temperature of the aqueous monomer solution at the time of polymerization reaches 50 ° C. or more.
- the amount of surfactant and / or dispersant used can be appropriately determined according to the type.
- the amount of the surfactant and / or dispersing agent used is such that the surface tension of the obtained water-absorbent resin powder is preferably 60 [mN / m] or more, more preferably 65 [mN / m] or more, and still more preferably 67 [ mN / m] or more, more preferably 69 [mN / m] or more, and most preferably 70 [mN / m] or more.
- the return amount may increase when used with a paper diaper.
- a surfactant having reactivity or polymerizability with the water-absorbent resin powder or its monomer for example, unsaturated polymerizable group (especially ⁇ , ⁇ -unsaturated).
- a surfactant having a saturated double bond), a reactive group (hydroxyl group or amino group), or a hydrophilic surfactant having a high solubility in water for example, HLB is 1 to 18, particularly preferably 8 to 15).
- HLB hydrophilic surfactant having a high solubility in water
- nonionic surfactants those exemplified in International Publication No. 2011/078298 are preferably used.
- nonionic surfactants are preferred, nonionic surfactants having a polyoxyethylene chain in the molecule are more preferred, and polyoxyethylene sorbitan fatty acid esters are most preferred.
- the amount of these surfactants to be used depends on the type of surfactant to be used or the intended physical properties (particularly the water absorption rate and surface tension), but is typically 0% relative to the amount of monomer used. More than 0 and not more than 0.03% by weight, more preferably more than 0 and less than 0.015% by weight, still more preferably more than 0 and less than 0.01% by weight, most preferably 0. Exceeding 0.008% by weight or less.
- the amount of the surfactant used can also be applied to the water-absorbing resin powder after polymerization, and if necessary, after coating the surfactant described in “(3-5) Surface treatment step” described later.
- the present invention can also be applied to a water absorbent resin powder as a final product to be obtained.
- the resin solid content of the hydrated gel before gel pulverization is 10 to 80% by weight, preferably 30 to 80% by weight, more preferably 40 to 80% by weight, and still more preferably, from the viewpoint of physical properties. Is 45 to 60% by weight, particularly preferably 50 to 60% by weight.
- the resin solid content is less than 10% by weight, the softness of the hydrogel increases, so that it may be difficult to control the particle shape or particle size distribution.
- the resin solid content exceeds 80% by weight, the hardness of the water-containing gel increases, which may make it difficult to control the particle shape or particle size distribution.
- the resin solid content of the hydrated gel should be appropriately controlled by polymerization concentration or water evaporation during polymerization, addition of water-absorbent resin fine powder to the polymerization process (fine powder recycling process), water addition after polymerization or partial drying as necessary. Can do.
- the resin solid content before gel pulverization is obtained by the loss on drying described in the above (1-3) (f).
- the CRC of the hydrogel before gel grinding (referred to herein as “gel CRC”) is preferably 10 to 35 [g / g], more preferably 10 to 32 [g / g]. [G / g] is more preferable, and 15 to 30 [g / g] is particularly preferable.
- the gel CRC can be appropriately controlled by the addition amount of a crosslinking agent during polymerization, other polymerization concentrations, and the like.
- the water-soluble content (gel Ext) of the hydrogel before gel pulverization is preferably 0.1 to 10% by weight, more preferably 0.5 to 8% by weight, and still more preferably 1 to 5% by weight.
- the gel Ext exceeds 10% by weight, the weight average molecular weight of the water-soluble component that increases due to shearing by gel pulverization becomes excessive, and the desired liquid permeability may not be obtained.
- the gel Ext is preferably smaller, but the lower limit is in the above range from the viewpoint of (c) the balance with the gel CRC, the production cost necessary for reducing the gel Ext, or the productivity reduction. .
- the weight average molecular weight of the water-soluble matter in the hydrous gel before pulverization of the gel is preferably 50,000 to 450,000 [Da], and preferably 100,000 to 430,000 [Da]. ], More preferably 150,000 to 400,000 [Da].
- the weight-average molecular weight of the water-soluble component is less than 50,000 [Da]
- the particle size of the particulate hydrous gel obtained after gel pulverization may become fine, and a water-absorbent resin powder having desired physical properties may not be obtained.
- the weight average molecular weight of the water-soluble component exceeds 450,000 [Da]
- the crosslinking point is reduced and affected by shear more than necessary, and performance such as an increase in the water-soluble component after gel pulverization is obtained. There is a risk of lowering.
- the weight average molecular weight of the water-soluble component can be appropriately controlled by the amount of the crosslinking agent added during polymerization or the polymerization concentration and, if necessary, a chain transfer agent.
- (3-2) Gel pulverization step This step is a step performed using the gel pulverization apparatus according to the present invention.
- the hydrated gel-like crosslinked polymer during or after the polymerization described above is subdivided to form particulate hydrated water.
- This is a step of obtaining a gel-like crosslinked polymer.
- this process is called “gel grinding” to distinguish from “pulverization” in the following (3-4) grinding process / classification process.
- the gel pulverization apparatus used in the gel pulverization step of the present invention is the gel pulverization apparatus of the present invention, and the configuration, temperature, and operating conditions of the gel pulverization apparatus are as described in [2] above. .
- the gel pulverization in the present invention is carried out on the hydrous gel after polymerization, but it can also be carried out on a “sufficiently gelled” gel dispersed in an aqueous solution.
- the “sufficient gelled state” means that the hydrogel is subdivided by applying a shearing force after the point when the polymerization temperature reaches the maximum (also referred to as “polymerization peak temperature” in this specification). The state where you can do.
- the polymerization rate of the monomer in the aqueous monomer solution (also known as conversion rate; the polymerization rate is calculated from the polymer amount calculated from the pH titration of the hydrogel and the residual monomer amount) is preferably 90 mol% or more More preferably 93 mol% or more, still more preferably 95 mol% or more, and particularly preferably 97 mol% or more. .
- a hydrogel having a monomer polymerization rate in the above range is gel pulverized.
- the polymerization rate of the monomer indicates “sufficiently gelled state”. Is prescribed.
- the hydrogel during or after polymerization preferably the hydrogel after polymerization
- the gel grinding process can be carried out more smoothly.
- disconnect or crush what can cut
- disconnection or crushing should just be a magnitude
- the weight of one of the crushed gel pieces is less than one tenth of “the weight of the hydrogel crosslinked polymer introduced into the gel pulverizer per second”, the energy during the pulverization is also crushed. It will be added as the GGE of the hour.
- the hydrogel crosslinked polymer (hydrogel) obtained in the polymerization step is pulverized into particles by using the above-described gel pulverizer of the present invention.
- the gel particle diameter can be controlled by classification or blending, but preferably the gel particle diameter is controlled by the gel crusher according to the present invention.
- the weight-average particle diameter (D50) (specified by sieve classification) of the particulate hydrogel after gel pulverization is preferably 350 to 2,000 ⁇ m, more preferably 400 to 1500 ⁇ m, still more preferably 500 to 1. , 000 ⁇ m.
- the logarithmic standard deviation ( ⁇ ) of the particle size distribution is preferably 0.2 to 1.5, more preferably 0.2 to 1.2, and still more preferably 0.2 to 1.0.
- the shearing / compressing force applied to the hydrogel may be uneven or insufficient. Furthermore, since the drying method is different between the inside and the surface portion of the hydrogel, particles having non-uniform physical properties are generated by pulverization after drying, and the physical properties may be lowered as a whole. On the other hand, when the weight average particle size is less than 350 ⁇ m, the surface area of the hydrated gel is increased and the gel is extremely easily dried. Therefore, the residual monomer is insufficiently reduced in the drying step, and the residual monomer is increased.
- the addition of a special technique as described above requires a large amount of a surfactant or an organic solvent for polymerization or classification, deteriorates productivity (cost increase), or increases the water-absorbing resin. Not only is it difficult to obtain a particulate hydrogel having a weight average particle diameter of less than 350 ⁇ m because of the new problem of causing deterioration of physical properties (increase in residual monomer or increase in fine powder) and the like. It is not preferable.
- the log standard deviation ( ⁇ ) is less than 0.2.
- Special operations such as classification of the gel after pulverization or particle size control during polymerization before gel pulverization are required. Therefore, in consideration of productivity and cost, it is not preferable and practically impossible to obtain a particulate hydrogel having a logarithmic standard deviation ( ⁇ ) of less than 0.2.
- the method for controlling the particle size include gel pulverization in the present invention, and the gel pulverization may be performed using the gel pulverization apparatus according to the present invention under such a condition that the particle size is exhibited.
- the gel CRC of the particulate hydrogel after gel pulverization is preferably 10 to 35 [g / g], more preferably 10 to 32 [g / g], and further preferably 15 to 30 [g / g]. preferable.
- the gel CRC after gel pulverization is preferably ⁇ 1 to +3 [g / g], and preferably +0.1 to +2 [g / g] with respect to the gel CRC before gel pulverization. More preferred is +0.3 to +1.5 [g / g].
- gel CRC may be reduced by using a crosslinking agent or the like during gel pulverization, it is preferable to increase gel CRC within the above range.
- the gel Ext of the particulate hydrogel after pulverization of the gel is preferably 0.1 to 20% by weight, more preferably 0.1 to 10% by weight, still more preferably 0.1 to 8% by weight, 1 to 5% by weight is particularly preferred.
- the amount of increase in gel Ext of the particulate hydrogel after gel pulverization is preferably 5% by weight or less, more preferably 4% by weight or less, and still more preferably 3% by weight or less. 2% by weight or less is particularly preferable, and 1% by weight or less is most preferable.
- the lower limit may be negative (for example, -3.0% by weight, further -1.0% by weight), but is usually 0% by weight or more, preferably 0.1% by weight or more, more preferably 0.0% by weight. It is 2% by weight or more, more preferably 0.3% by weight or more.
- the gel Ext is increased so that it is within an arbitrary range of the above upper limit value and lower limit value, preferably 0 to 5.0% by weight, more preferably 0.1 to 3.0% by weight.
- the gel may be crushed until it is done.
- gel Ext may be reduced by use of a crosslinking agent etc. at the time of gel grinding
- the significant number of the increase amount of the gel Ext is one digit after the decimal point. For example, 5% by weight and 5.0% by weight are treated as being the same.
- the lower limit is 10,000 [Da] or more as the amount of increase in the weight average molecular weight of the water-soluble component of the hydrous gel by gel pulverization.
- 20,000 [Da] or more is more preferable, and 30,000 [Da] or more is more preferable.
- the upper limit is preferably 500,000 [Da] or less, more preferably 400,000 [Da] or less, further preferably 250,000 [Da] or less, and particularly preferably 100,000 [Da] or less.
- the increase in the weight-average molecular weight of the water-soluble matter of the particulate hydrogel after gel pulverization relative to the hydrogel before gel pulverization is 10,000 to 500,000 [Da], preferably Is from 20,000 to 400,000 [Da], more preferably from 30,000 to 250,000 [Da], and even more preferably from 30,000 to 100,000 [Da].
- the increase in the weight average molecular weight of the water-soluble component is often less than 10,000 [Da], but in the present invention, more gel grinding energy (GGE), that is, It is preferable to increase the weight average molecular weight of the water-soluble component by cutting the polymer main chain portion by applying more shearing force and compressive force to the hydrous gel.
- GGE gel grinding energy
- the increase in the weight average molecular weight of the water-soluble component by gel grinding exceeds 500,000 [Da]
- excessive mechanical external force acts on the hydrous gel, and the cross-linked polymer chain is cut, resulting in excessive water solubility.
- the amount of water increases and the physical properties of the water-absorbent resin are lowered.
- the resin solid content of the particulate hydrogel after gel grinding is preferably 10 to 80% by weight, more preferably 30 to 80% by weight, from the viewpoint of physical properties. It is more preferably 50 to 80% by weight, 45 to 85% by weight or 45 to 70% by weight, and particularly preferably 50 to 60% by weight or 45 to 60% by weight.
- pulverization can be suitably controlled by the resin solid content before gel grinding
- the production amount of the water-absorbent resin powder is 1 to 20 [t / t by continuous gel grinding using a continuous kneader, meat chopper, or the like. hr] or 1 to 10 [t / hr], the physical properties of the particulate hydrous gel may be evaluated by sampling and measuring at least 10 points in total for every 100 kg of the hydrous gel.
- This step is a step of drying the particulate hydrous gel obtained in the gel pulverization step to obtain a dry polymer, and the drying method preferably applied in the present invention will be described below.
- drying method in the drying process of the present invention heat drying, hot air drying, vacuum drying, infrared drying, microwave drying, drum dryer drying, azeotropic dehydration drying with a hydrophobic organic solvent, high humidity using high temperature steam
- hot air drying is preferable, and hot air drying with a dew point of 40 to 100 ° C., more preferably 50 to 90 ° C. is preferably used.
- a ventilation dryer is preferable, and a ventilation belt type hot air dryer is more preferably used.
- the direction of the hot air used in the dryer is perpendicular to the hydrous gel layer laminated on the vent belt (for example, combined use in the vertical direction, Or, an upward direction or a downward direction) is essential.
- the ventilation belt type dryer is not used or when hot air in the vertical direction is not used, uniform drying cannot be performed, and physical properties such as liquid permeability may be deteriorated.
- the “vertical direction” refers to the top and bottom (from the top to the bottom of the gel layer or the gel layer) with respect to the gel layer (particulate hydrogel having a thickness of 10 to 300 mm laminated on a punching metal or metal net). It refers to the state of ventilation from the bottom to the top), and is not limited to the strict vertical direction as long as it is vented in the vertical direction.
- hot air in an oblique direction may be used. In this case, it is within 30 °, preferably within 20 °, more preferably within 10 °, still more preferably within 5 °, particularly preferably 0 ° with respect to the vertical direction. Hot air is used.
- the water-containing gel pulverized by the gel pulverizer of the present invention is preferably dried under the following drying conditions, whereby the water-absorbing resin powder surface-treated water-absorbing resin powder obtained by surface treatment, liquid permeability and water absorption Speed can be improved.
- the drying temperature in the drying step is 100 to 300 ° C, preferably 150 to 250 ° C, more preferably 160 to 220 ° C, and still more preferably. Is 170-200 ° C.
- the drying temperature is 100 to 300 ° C.
- both shortening of the drying time and reduction of coloring of the resulting dried polymer can be achieved.
- the water absorption magnification under pressure of the resulting water absorbent resin powder tends to be improved.
- the drying temperature exceeds 300 ° C., the polymer chain is affected and the physical properties may be deteriorated.
- the drying temperature is less than 100 ° C., there is no change in the water absorption rate, and an undried product is generated, and clogging occurs during the subsequent pulverization process.
- the drying time in the drying step in the present invention depends on the surface area of the particulate water-containing gel, the type of the dryer, etc., and is appropriately set so as to achieve the desired moisture content. However, it is preferably 1 minute to 10 hours, more preferably 5 minutes to 2 hours, still more preferably 10 minutes to 1 hour, particularly preferably 15 minutes to 45 minutes.
- the time is preferably shorter from the viewpoint of coloring with the water-absorbent resin powder, specifically, preferably within 2 hours, more preferably within 1 hour, further preferably within 30 minutes, particularly preferably within 10 minutes, Most preferably within 2 minutes.
- the air velocity of the hot air in the above-described ventilation dryer, particularly the belt-type dryer is 0.8 to 2.5 in the vertical direction (vertical direction). [M / s], preferably 1.0 to 2.0 [m / s].
- the wind speed may be controlled within a range that does not impair the effects of the present invention. For example, it may be controlled within a range of 70% or more, preferably 90% or more, and more preferably 95% or more of the drying time.
- the said wind speed is represented by the average flow velocity of the hot air which passes a perpendicular
- the hot air used in the ventilating belt dryer contains at least water vapor and has a dew point of preferably 30 to 100 ° C., more preferably 30 to 80 ° C. Residual monomer can be reduced by controlling the dew point of hot air or, more preferably, the gel particle size within the above range, and further the reduction of the bulk specific gravity of the dried polymer can be prevented.
- the dew point is a value when the moisture content of the particulate hydrogel is at least 10% by weight, preferably 20% by weight or more.
- the dew point is high in the initial stage of drying; Specifically, hot air having a dew point of preferably 10 to 50 ° C., more preferably 15 to 40 ° C. higher than that near the dryer outlet is preferably brought into contact with the particulate hydrogel near the dryer inlet.
- the particulate hydrogel obtained in the gel pulverization step is dried in the main drying step to obtain a dry polymer, and is obtained from its loss on drying (1 g of powder or particles is heated at 180 ° C. for 3 hours).
- the resin solid content is preferably more than 80% by weight, more preferably 85 to 99% by weight, still more preferably 90 to 98% by weight, and particularly preferably 92 to 97% by weight.
- the surface temperature of the particulate hydrogel obtained in the gel pulverization step immediately before being charged into the dryer is preferably 40 to 110 ° C, more preferably 60 to 110 ° C, and more preferably 60 to 100 ° C is more preferable, and 70 to 100 ° C is particularly preferable.
- the temperature is less than 40 ° C., a balloon-like dried product is generated at the time of drying, and a lot of fine powder is generated at the time of pulverization, which may cause a decrease in physical properties of the water absorbent resin.
- the surface temperature of the particulate hydrogel before drying exceeds 110 ° C., the water-absorbent resin may be deteriorated (for example, increased in water-soluble content) or colored after drying.
- the (3-2) gel pulverization step is different from the resin solid content at the time of pulverization, particularly in that the object to be pulverized has undergone a drying step (preferably dried to the resin solid content).
- the water-absorbent resin particles obtained after the pulverization step may be referred to as a pulverized product.
- the dried polymer obtained in the drying step can be used as a water-absorbent resin powder as it is, but it can be controlled to a specific particle size in order to improve physical properties in the surface treatment step, particularly the surface cross-linking step described later. preferable.
- the particle size control can be appropriately performed not only in the main pulverization step and the classification step, but also in a polymerization step, a fine powder recovery step, a granulation step, and the like.
- the particle size is defined by a standard sieve (JIS Z8801-1 (2000)).
- the pulverizer that can be used in the pulverization process is not particularly limited.
- vibration mill, roll granulator, knuckle type pulverizer, roll mill, high-speed rotary pulverizer (pin mill, hammer mill, screw mill), cylinder And the like are examples of vibration mill, roll granulator, knuckle type pulverizer, roll mill, high-speed rotary pulverizer (pin mill, hammer mill, screw mill), cylinder And the like.
- classification operation is performed so that the following particle size is obtained.
- the classification operation is preferably performed before the surface crosslinking step (first classification step), and further after surface crosslinking.
- a classification operation (second classification step) may be performed.
- the classification operation is not particularly limited, but classification is performed as follows in sieving using a sieve. That is, when the particle size distribution of the water-absorbent resin particles is set to 150 to 850 ⁇ m, for example, first, the pulverized product is sieved with a sieve having an opening of 850 ⁇ m, and the pulverized product that has passed through the sieve has an opening of 150 ⁇ m or 150 ⁇ m.
- the weight average particle diameter (D50) of the water absorbent resin particles after classification is preferably 250 to 500 ⁇ m, more preferably 300 to 500 ⁇ m, and more preferably 350 to More preferably, it is 450 ⁇ m. Further, the smaller the number of fine particles that pass through a sieve having a mesh size of 150 ⁇ m (JIS standard sieve), the more preferable. Usually, 0 to 5% by weight is preferable, and 0 to 3% by weight is more preferable with respect to the entire water-absorbent resin particles. 0 to 1% by weight is more preferable.
- the ratio of the particles having a particle diameter of 150 ⁇ m or more and less than 850 ⁇ m, and the ratio of the particles having a particle diameter of 150 ⁇ m or more and less than 710 ⁇ m is preferably 95% by weight or more with respect to the entire water-absorbent resin particles.
- the logarithmic standard deviation ( ⁇ ) of the particle size distribution is preferably 0.20 to 0.50, more preferably 0.25 to 0.50, still more preferably 0.25 to 0.45, and 0.30 to 0. .40 is particularly preferred.
- the logarithmic standard deviation ( ⁇ ) of the particle size and particle size distribution is measured by the method described in the specification of European Patent No. 1594556.
- the particle size before surface cross-linking is preferably applied to the final product after surface cross-linking.
- the water-absorbent resin powder obtained by gel grinding in the present invention can have a specific internal cell ratio.
- the water-absorbing resin before surface crosslinking is not limited to the internal cell ratio and particle size distribution, but the surface crosslinking of the present invention will be described below.
- the method for producing the polyacrylic acid (salt) water-absorbing resin powder according to the present invention is preferable for improving water absorption performance (absorbability against pressure, liquid permeability, absorption speed, etc.). Further includes a surface treatment step.
- the surface treatment step includes a surface cross-linking step performed using a known surface cross-linking agent and a surface cross-linking method, and further includes other addition steps as necessary.
- Examples of the surface cross-linking agent that can be used in the present invention include various organic or inorganic cross-linking agents, and organic surface cross-linking agents are preferable.
- a surface cross-linking agent a polyhydric alcohol compound, an epoxy compound, a polyvalent amine compound or a condensate thereof with a haloepoxy compound, an oxazoline compound, a (mono, di, or poly) oxazolidinone compound, an alkylene carbonate compound
- a dehydration-reactive crosslinking agent composed of a polyhydric alcohol compound, an alkylene carbonate compound, or an oxazolidinone compound, which requires a reaction at a high temperature, can be used.
- the amount of the surface cross-linking agent used is suitably determined as preferably about 0.001 to 10 parts by weight, more preferably about 0.01 to 5 parts by weight with respect to 100 parts by weight of the water-absorbent resin particles.
- Water is preferably used in accordance with the surface cross-linking agent.
- the amount of water used is preferably in the range of 0.5 to 20 parts by weight, more preferably in the range of 0.5 to 10 parts by weight with respect to 100 parts by weight of the water absorbent resin particles.
- the inorganic surface crosslinking agent and the organic surface crosslinking agent are used in combination, it is preferably in the range of 0.001 to 10 parts by weight, more preferably 0.01 to 5 parts by weight, with respect to 100 parts by weight of the water-absorbent resin particles. It is used together in the range.
- a hydrophilic organic solvent may be used, and the amount used is preferably in the range of 0 to 10 parts by weight, more preferably 0 to 5 parts by weight, relative to 100 parts by weight of the water-absorbent resin particles. Range. Further, when the crosslinking agent solution is mixed with the water-absorbent resin particles, the range does not hinder the effect of the present invention, for example, preferably 0 to 10 parts by weight, more preferably 0 to 5 parts by weight, and still more preferably 0 to 1 part.
- the water-insoluble fine particle powder and the surfactant may be present together in parts by weight.
- the surfactant used or the amount of use thereof is exemplified in US Pat. No. 7,473,739.
- a vertical or horizontal high-speed rotary stirring mixer is preferably used.
- the rotational speed of the mixer is preferably 100 to 10,000 rpm, more preferably 300 to 2,000 rpm.
- the residence time of the water absorbent resin in the apparatus is preferably within 180 seconds, more preferably from 0.1 to 60 seconds, and even more preferably from 1 to 30 seconds.
- a surface cross-linking method using a radical polymerization initiator (US Pat. No. 4,783,510, International Publication No. 2006/062258) or a water-absorbing method instead of the surface cross-linking using the surface cross-linking agent described above.
- a surface cross-linking method of polymerizing monomers on the surface of the resin (US Application Publication Nos. 2005/048221, 2009/0239966, and International Publication No. 2009/048160) may be used.
- the radical polymerization initiator preferably used is a persulfate, and preferable monomers used as necessary include acrylic acid (salt) or other cross-linking agents described above,
- the preferred solvent used is water.
- the addition process which adds any one or more of a polyvalent metal salt, a cationic polymer, or an inorganic fine particle is further included simultaneously with the surface crosslinking process mentioned above or separately.
- the method further includes an addition step of adding any one or more of a polyvalent metal salt or inorganic fine particles. That is, in addition to the organic surface cross-linking agent, an inorganic surface cross-linking agent may be used or used in combination to improve liquid permeability and water absorption rate.
- the inorganic surface cross-linking agent can be used simultaneously with or separately from the organic surface cross-linking agent.
- Examples of the inorganic surface crosslinking agent to be used include divalent or higher, preferably trivalent or tetravalent polyvalent metal salts (organic salts or inorganic salts) or hydroxides.
- Examples of the polyvalent metal that can be used include aluminum and zirconium, and examples thereof include aluminum lactate and aluminum sulfate. An aqueous solution containing aluminum sulfate is preferred.
- These inorganic surface crosslinks are used simultaneously or separately with the organic surface crosslinker. Surface cross-linking with a polyvalent metal is disclosed in International Publication Nos. 2007/121037, 2008/09843, 2008/09842, U.S. Pat. Nos. 7,157,141, 6,605,673, and 6620889, and U.S. Pat. 2005/0288182, 2005/0070671, 2007/0106013, and 2006/0073969.
- a cationic polymer particularly a weight average molecular weight of about 5,000 to 1,000,000 may be used simultaneously or separately to improve liquid permeability.
- the cationic polymer used is preferably, for example, a vinylamine polymer or the like.
- inorganic fine particles may be added.
- silicon dioxide or the like is preferable, and exemplified in US Pat. No. 7,638,570.
- Preferred in the production method in the present invention is a method for producing a water-absorbent resin including a step of adding any one or more of the above polyvalent metals, cationic polymers, and inorganic fine particles.
- These additives are preferably used together with or separately from the above-mentioned covalently-bonded surface cross-linking agent, and can further solve the problem of the present invention (improvement in water absorption capacity under pressure).
- the water absorption resin powder after surface cross-linking preferably has a water absorption capacity (AAP) under pressure of 20 [g / g] or more (more preferably 22 [g / g] or more, still more preferably 24 [g / g]. ], Most preferably 24.5 [g / g] or more, and the upper limit of the AAP is preferably 35 [g / g] or less, more preferably 30 [g / g] or less, still more preferably 28.
- AAP water absorption capacity
- the non-pressurized water absorption capacity (CRC) after surface crosslinking is 10 [g / g] or more (more preferably 20 [g / g] or more, more preferably 25 [g / g] or more, most preferably 27 [g / g] or more, and the upper limit of the CRC is preferably 50 [g / g] or less, more preferably 45 [g / g] or less.
- the reaction temperature is preferably in the range of 42 [g / g] or less). And the like to adjust the, reaction time, etc. as appropriate are surface crosslinked.
- an evaporation monomer recycling step, granulation step, fine powder removal step, fine powder recycling step, etc. may be provided.
- the following additives may be used if necessary for any or all of the above. That is, water-soluble or water-insoluble polymers, lubricants, chelating agents, deodorants, antibacterial agents, water, surfactants, water-insoluble fine particles, antioxidants, reducing agents, etc. 0 to 30% by weight, more preferably 0.01 to 10% by weight can be added and mixed. These additives can also be used as a surface treatment agent.
- the production method according to the present invention may include a fine powder recycling step.
- the fine powder recycling step is a state in which the fine powder generated in the drying step and, if necessary, the pulverization step and the classification step (particularly fine powder containing 70% by weight or more of a powder having a particle size of 150 ⁇ m or less) is separated or water It is a process that is summed and recycled to a polymerization process or a drying process, and methods described in US Patent Application Publication No. 2006/247351, US Pat. No. 6,228,930, and the like can be applied.
- an oxidizing agent, an antioxidant, water, a polyvalent metal compound, a water-insoluble inorganic or organic powder such as silica or metal soap, a deodorant, an antibacterial agent, a polymer polyamine, pulp or thermoplastic fiber Etc. may be added to the water-absorbent resin in an amount of 0 to 3% by weight, preferably 0 to 1% by weight.
- the AAP (water absorption capacity under pressure) of the water-absorbent resin powder obtained in the present invention is 17% as an AAP under a pressure of 4.8 kPa as an example of means for achieving the above polymerization in order to prevent leakage in paper diapers.
- g / g] or more preferably 20 [g / g] or more, more preferably 22 [g / g] or more, still more preferably 23 [g / g] or more, and 24 [g / g] or more.
- Particularly preferred is 24.5 [g / g] or more.
- AAP is not particularly limited, it is preferably 35 [g / g] or less, more preferably 30 [g / g] or less, and even more preferably 28 [g / g] or less, in view of balance with other physical properties.
- the AAP can be adjusted (improved) by surface cross-linking after particle size control. Note that the value of the AAP may change depending on the process performed after the surface cross-linking process.
- the novel water-absorbent resin of the present invention can be obtained, and the liquid permeability (SFC) can be improved while maintaining the water absorption rate (FSR).
- the SFC (saline flow conductivity) of the water-absorbent resin powder obtained in the present invention is the surface after the above-mentioned manufacturing method, particularly the gel pulverization of the present invention, preferably after the above-mentioned particle size control, in order to prevent the leakage of paper diapers.
- 0.69% sodium chloride aqueous solution flow conductivity which is a liquid flow characteristic under pressure Is preferably 10 [ ⁇ 10 ⁇ 7 ⁇ cm 3 ⁇ s ⁇ g ⁇ 1 ] or more, more preferably 20 [ ⁇ 10 ⁇ 7 ⁇ cm 3 ⁇ s ⁇ g ⁇ 1 ] or more, and 30 [ ⁇ 10 ⁇ 7.
- SFC is a well-known measurement method and can be defined, for example, in US Pat. No. 5,562,646.
- the improvement of the liquid permeability particularly the improvement of SFC, particularly the SFC in the above range, particularly the SFC of 10 [ ⁇ 10 ⁇ 7 ⁇ cm 3 ⁇ s ⁇ g ⁇ 1 ] or more is more remarkable. Therefore, it can be suitably applied to a method for producing such a highly liquid-permeable water-absorbent resin.
- the CRC (water absorption capacity without pressure) of the water absorbent resin powder obtained in the present invention is preferably 10 [g / g] or more, more preferably 20 [g / g] or more, and further 25 [g / g] or more. It is preferably 27 [g / g] or more.
- the upper limit of CRC is not particularly limited, but is preferably 50 [g / g] or less, more preferably 45 [g / g] or less, and still more preferably 42 [g / g] or less from the balance of other physical properties.
- the CRC can be appropriately controlled by the amount of the crosslinking agent during polymerization and the subsequent surface crosslinking (secondary crosslinking).
- Ext (water soluble component) of the water-absorbent resin powder obtained in the present invention is preferably 35% by weight or less, and preferably 25% by weight or less in order to prevent stickiness and the like during use in a paper diaper due to the effect of liquid elution. More preferably, it is more preferably 15% by weight or less, and particularly preferably 10% by weight or less.
- the Ext can be appropriately controlled by the amount of the crosslinking agent during polymerization and the increase in the amount of water-soluble components in the subsequent gel grinding.
- Residual Monomers (residual monomers) of the water-absorbent resin powder obtained in the present invention are usually 500 ppm or less, preferably 0 to 400 ppm, more preferably 0 to 300 ppm as an example of means for achieving the polymerization. Particularly preferably, it is controlled to 0 to 200 ppm.
- the residual monomer can be appropriately controlled by a polymerization initiator at the time of polymerization and subsequent drying conditions.
- the FSR (water absorption rate) of the water-absorbent resin powder obtained in the present invention is usually 0.2 [g / (g ⁇ s)] or more as an example of means for achieving the above polymerization in order to prevent leakage in paper diapers. And preferably 0.25 [g / (g ⁇ s)] or more, more preferably 0.30 [g / (g ⁇ s)] or more, and 0.35 [g / (g ⁇ s)] or more. More preferably, 0.40 [g / (g ⁇ s)] or more is particularly preferable, and 0.45 [g / (g ⁇ s)] or more is most preferable.
- the upper limit value of the FSR is 1.00 [g / (g ⁇ s)] or less.
- the measuring method of FSR can be defined in International Publication No. 2009/016055.
- the FSR can be adjusted by the production method of the present invention and the particle size control after drying.
- the water absorption rate is improved, especially FSR is improved, particularly to the FSR in the above range, particularly to FSR 0.30 [g / (g ⁇ s)] or more, the water absorption rate is high. It can apply suitably for the manufacturing method of an adhesive resin.
- the thermal conductivity of the water-absorbent resin powder obtained in the present invention is preferably 125 [mW / (m ⁇ K)] or less in order to improve the heat retention of the paper diaper. It is more preferably 120 [mW / (m ⁇ K)] or less, and still more preferably 116 [mW / (m ⁇ K)] or less.
- the lower limit of the thermal conductivity is usually 20 [mW / (m ⁇ K)] although it depends on the measuring device.
- the ratio of particles less than 150 ⁇ m after impact resistance test of the water-absorbent resin powder obtained in the present invention is the heat retention performance, handling property when making paper diapers, In order to improve the liquid permeation performance, it is preferably 0 to 4.5% by mass, more preferably 0 to 4.0% by mass, still more preferably 0 to 3.5% by mass, It is particularly preferably from 3.0 to 3.0% by mass, and most preferably from 0 to 2.5% by mass.
- Mass average particle diameter D50, logarithmic standard deviation ⁇ of particle size distribution The mass average particle diameter D50 of the water-absorbent resin powder obtained in the present invention is preferably 250 to 500 ⁇ m, more preferably 300 to 500 ⁇ m, and still more preferably 350 to 460 ⁇ m from the viewpoint of improving physical properties.
- the amount is usually 0 to 4.5% by mass with respect to the entire water-absorbent resin powder. It is preferably 0 to 4.0% by mass, more preferably 0 to 3.5% by mass, particularly preferably 0 to 3.0% by mass, and 0 to 2.5% by mass. Most preferably, it is mass%.
- the amount of the water-absorbent resin particles is generally preferably 0 to 5% by mass, and preferably 0 to 3% by mass. % Is more preferable, and 0 to 1% by mass is still more preferable.
- the ratio of the particles having a particle diameter of 150 ⁇ m or more and less than 850 ⁇ m, and further the ratio of the particles having a particle diameter of 150 ⁇ m or more and less than 710 ⁇ m is preferably 95% by mass or more based on the entire water-absorbent resin particles. More preferably, it is adjusted to 98% by mass or more (the upper limit is 100% by mass).
- the proportion of particles that pass through a sieve having an aperture of 710 ⁇ m and not passing through a sieve having an aperture of 500 ⁇ m is preferably 36% by mass or less, more preferably 34% by mass or less, and still more preferably 32. It is below mass%.
- the logarithmic standard deviation ( ⁇ ) of the particle size distribution is preferably 0.20 to 0.50, more preferably 0.25 to 0.50, still more preferably 0.25 to 0.45, and 0.30 to 0. .40 is particularly preferred.
- the logarithmic standard deviation ( ⁇ ) of the particle size and particle size distribution is measured by the method described in the specification of European Patent No. 1594556.
- the particle size before surface cross-linking is preferably applied to the final product after surface cross-linking.
- the surface tension of the water-absorbent resin powder obtained in the present invention is preferably 60.0 [mN / m] or more, more preferably from the viewpoint of reducing the amount of liquid returned from the paper diaper. Is 65.0 [mN / m] or more, more preferably 67.0 [mN / m] or more, still more preferably 69.0 [mN / m] or more, particularly preferably 70.0 [mN / m] or more. Most preferably, it is 72.0 [mN / m] or more.
- the water-absorbent resin powder obtained in the present invention is one or more of the aforementioned polyvalent metal salts and inorganic fine particles in order to improve performance such as liquid permeability. It is preferable to contain.
- the content thereof is preferably 0.01% by mass to 1% by mass, more preferably 0.02% by mass to 0.5% by mass.
- the use of the water-absorbent resin powder obtained by the production method according to the present invention is not particularly limited, but preferably paper diapers, sanitary napkins, incontinence pads, etc. Used in absorbent articles.
- High concentration diapers paper diapers that use a large amount of water-absorbent resin per paper diaper, which has been a problem with odors and coloring from raw materials, especially when used in the upper layer of the absorbent article In addition, it exhibits excellent performance.
- the content of the water absorbent resin in the absorbent body optionally containing other absorbent materials (fibrous materials such as pulp fibers) (core concentration, that is, the total of the water absorbent resin powder and the fibrous material)
- core concentration that is, the total of the water absorbent resin powder and the fibrous material
- the content of the water-absorbent resin powder with respect to the amount is preferably 30 to 100% by weight, more preferably 40 to 100% by weight, still more preferably 50 to 100% by weight, still more preferably 60 to 100% by weight, ⁇ 100 wt% is particularly preferred, and 75 to 95 wt% is most preferred.
- the water-absorbent resin powder obtained by the production method according to the present invention when used at the above concentration, particularly in the upper layer part of the absorbent body, it is excellent in the diffusibility of the absorbing liquid such as urine due to its high liquid permeability. Liquid distribution is performed, and the amount of absorption of the entire absorbent article is improved. Further, it is possible to provide an absorbent article in which the absorbent body maintains a hygienic white state. Moreover, since it is excellent in heat retention, it is possible to achieve an excellent wearing feeling in any environment.
- the gel CRC was operated in the same manner as above except that 0.4 g of hydrous gel was used and the free swelling time was 24 hours. Further, separately, the resin solid content of the hydrogel was measured to determine the weight of the water-absorbent resin in the 0.4 g of the hydrogel, and the gel CRC was calculated according to the following formula (4). In addition, it measured 5 times per sample and employ
- the gel Ext was operated in the same manner as above except that 5.0 g of hydrous gel cut to about 1 to 5 mm on a side with scissors was used and the stirring time was 24 hours. Further, separately, the resin solid content of the hydrogel was measured, the water-absorbing resin weight of the 5.0 g hydrogel was determined, and the gel Ext was calculated according to the following formula (6).
- C HCl HCl solution concentration [mol / L]
- Mw average molecular weight of monomer unit in acrylic acid (salt) polymer [g / mol] (For example, when the neutralization rate is 73 mol%, Mw is 88.1 [g / mol])
- F dil Dilution degree of filtrate containing dissolved polymer ms; Weight of hydrogel before measurement [g]
- Wn solid content of water-containing gel [% by weight] It is.
- (C) Weight average molecular weight of water soluble part The weight average molecular weight of water soluble part is the value which measured the weight average molecular weight of the polymer melt
- the apparatus is an apparatus composed of size exclusion chromatography, a refractive index detector, a light scattering detector, and a capillary viscometer.
- the measurement apparatus and measurement conditions are as follows.
- the differential refractive index (dn / dc) of the polymer to be analyzed is 0.00. Measurement was carried out as 12. In the case of a copolymer water-absorbing resin having a monomer content other than acrylic acid (salt) of 1 mol% or more, the differential refractive index (dn / dc) in a solvent specific to the polymer is measured. , And measured using the numerical value. Furthermore, data collection and analysis of refractive index, light scattering intensity, and viscosity were performed with Viscotek OmniSEC 3.1 (registered trademark) software. The weight average molecular weight (Mw) was calculated from the data obtained from the refractive index and the light scattering intensity.
- Weight average particle diameter (D50) and logarithmic standard deviation of particle size distribution ( ⁇ ) The weight average particle diameter (D50) and logarithmic standard deviation ( ⁇ ) of the water-absorbent resin were measured according to the measurement method described in European Patent No. 0349240. On the other hand, the weight average particle size (D50) and the logarithmic standard deviation ( ⁇ ) of the particle size distribution of the hydrogel were measured by the following methods.
- Emal 20% aqueous sodium chloride solution
- hydrogel solid content ⁇ wt%
- EMAL 20C surfactant, manufactured by Kao Corporation
- EMAR aqueous solution After 100 g of aqueous solution of EMAR was used to wash out all the hydrous gel on the sieve, 6000 g of EMAR aqueous solution was showered from the top (20 rpm) from the top while showering from a height of 30 cm (72 holes, open, liquid An amount of 6.0 [L / min] was used to pour the water injection range (50 cm 2 ) evenly over the entire sieve, and the hydrogel was classified. The hydrated gel on the classified first-stage sieve was drained for about 2 minutes and then weighed. The second and subsequent sieves were classified by the same operation, and after draining, the hydrated gel remaining on each sieve was weighed.
- the weight percentage was calculated from the following formula (7).
- the sieve openings after draining were plotted according to the following formula (8), and the particle size distribution of the hydrogel was plotted on logarithmic probability paper.
- the particle diameter corresponding to 50% by weight% R on the integrated sieve on the plot was defined as the weight average particle diameter (D50) of the hydrogel.
- the diameter of the internal bubbles (closed cells) existing in the water-absorbent resin is usually 1 to 300 ⁇ m, but when pulverized, the bubbles are preferentially pulverized from the portion close to the closed cells. Therefore, when the water absorbent resin is pulverized until the particle diameter is less than 45 ⁇ m, the obtained water absorbent resin contains almost no closed cells. Therefore, the dry density of the water-absorbent resin pulverized to less than 45 ⁇ m was evaluated as the true density in the present invention.
- a ball mill pot (Teraoka Co., Ltd .; Model No. 90 / inner dimensions; diameter 80 mm, height 75 mm, outer dimensions; diameter 90 mm, height 110 mm) and water-absorbing resin 15.0 g and cylindrical magnetic balls (diameter After adding 400 g (13 mm, length 13 mm), the mixture was operated at 60 Hz for 2 hours to obtain a water-absorbing resin that passed through a JIS standard sieve having a mesh size of 45 ⁇ m (particle diameter of less than 45 ⁇ m). About 6.0 g of the water-absorbing resin having a particle size of less than 45 ⁇ m, the dry density was measured after drying at 180 ° C. for 3 hours or more in the same manner as the above [apparent density]. The obtained measured value was defined as “true density” in the present invention.
- FSR Water absorption rate (free swelling rate)
- the water absorption rate “FSR” in the present invention is an abbreviation for Free Swell Rate and means the water absorption rate (free swelling rate). Specifically, “FSR” refers to the rate (unit: [g / (g ⁇ s)]) at which 1 g of the water-absorbent resin absorbs 20 g of 0.9 wt% sodium chloride aqueous solution.
- the time measurement was started at the same time as the poured sodium chloride aqueous solution contacted the water-absorbent resin. Then, when the upper surface of the sodium chloride aqueous solution in the beaker into which the aqueous sodium chloride solution was poured was observed at an angle of about 20 °, the upper surface that was the surface of the sodium chloride aqueous solution was absorbed by the water absorbent resin. The time measurement was completed (time ts [second]) when the surface of the water-absorbent resin that had absorbed the aqueous sodium chloride solution was replaced.
- FSR is expressed by the following formula (11)
- FSR [g / (g ⁇ s)] 20.0 / (ts [seconds] ⁇ 1.00) ...
- the above impact is a force determined empirically as representative of the impact force received by the water absorbent resin powder during the manufacturing process of the water absorbent resin powder. It can be widely applied to damage.
- the ratio [mass%] of particles having a particle diameter of less than 150 ⁇ m is represented by the following formula:
- the ratio of particles having an particle diameter of less than 150 ⁇ m after the impact test [mass%] ⁇ Mass of passed particles [g]) / (Mass of water absorbent resin powder [g]) ⁇ ⁇ 100 Sought according to.
- the thermal conductivity was measured using a thermal conductivity meter (manufactured by Kyoto Electronics Industry Co., Ltd .; rapid thermal conductivity meter QTM500).
- the internal volume of the powder container of the apparatus is a rectangular cylinder with a length of 30 mm, a width of 100 mm, a height of 60 mm, and a thickness of 5 mm.
- a polyimide film having a thickness of 25 ⁇ m is sandwiched between the bottom surface and a height of 3.3 mm from the bottom surface.
- a 100 mL mark is shown here.
- the probe is unique to the device, and a heater and thermocouple with a width of 1.5 mm and a length of 90 mm are mounted on a substrate with a known thermal conductivity. During measurement, the probe is passed through a polyimide film on the bottom of the powder container. A heater and thermocouple are in contact with the powder sample.
- the apparatus is used with a power supply of 100 V and 50 Hz, and before measurement, three types of standard samples with known thermal conductivity (0.0362 [W / (m ⁇ K)], 0.238 [W / (m ⁇ K) are used. )] And 1.416 [W / (m ⁇ K)]) were measured and calibrated.
- the heating conditions at this time were set such that the temperature saturated when heating was continued was 15 ⁇ 1 ° C. higher than the powder temperature before heating.
- the heater temperature after 30 seconds and 60 seconds after applying the current was read with a thermocouple, and the thermal conductivity was calculated from the following formula (12).
- required thermal conductivity was rounded off, and it was set as three significant figures.
- ⁇ ⁇ K ⁇ R ⁇ I 2 ⁇ ln (t2 / t1) / (T2-T1) ⁇ H ⁇ ⁇ 1000 ...
- ⁇ thermal conductivity [mW / (m ⁇ K)] K
- H Probe constant
- R Thermal resistance per unit length of probe heater [ ⁇ / m]
- T1 temperature at t1, t2 [° C.] It is.
- a hot plate manufactured by ASONE Corporation; NEO HOTPLATE HI-1000
- a stainless steel 400 mesh wire mesh 201 is attached to the bottom
- a heat insulating material 202 is attached to the side surface.
- a cylindrical acrylic resin cell (bottom area 28.3 cm 2 ) 200 having a thickness of 5 mm is placed, and a vinyl chloride resin piston 204 having a diameter of 59 mm and a weight of 62 g is inserted.
- a heat insulating material 203 having a width of 2 cm, a width of 2 cm, and a height of 1 cm is attached to the center of the piston bottom, and a thermocouple 205 is installed on the heat insulating material.
- K [W / (m ⁇ K)] is the thermal conductivity of the water absorbent resin powder
- T1 [° C.] is the temperature 15 minutes after the water absorbent resin powder reaches 24 ° C.
- the water-absorbent resin powder according to the present invention preferably has few 150 ⁇ m passing particles from the viewpoint of improving heat retention.
- a top sheet 208 of paper diapers and a cylindrical acrylic resin cell (bottom area 28) having an inner diameter of 60 mm and a thickness of 5 mm. .3 cm 2 ) 200 are placed in this order, and the acrylic resin cell has a diameter of 59 mm in which a stainless steel 400 mesh wire net 201 is attached to the bottom, a heat insulating material 202 is attached to the side, and a thermocouple 205 is installed in the center of the bottom.
- the piston 204 made of vinyl chloride resin having a weight of 62 g and a weight 210 (mass 1278 g) for applying a load are inserted.
- An absorber 30g is put on the wire net 201, a paper diaper back sheet 209, a piston 204 and a weight 210 are placed on the absorber 211, and then a cell is placed on a hot plate 206 and a top sheet 208 heated to 50 ° C. Then, heating to the absorber was started.
- Absorber heat loss Qd [J] is expressed by the following formula (14).
- Qd [J] 30 ⁇ 1 ⁇ (T2-30) (14) I asked more.
- polyacrylic acid (salt) water-absorbent resin powder As a production device for polyacrylic acid (salt) water-absorbent resin powder, polymerization process, gel pulverization process, drying process, pulverization process, classification process, surface cross-linking process, cooling process, sizing process, and connecting between each process A continuous manufacturing apparatus composed of a transportation process was prepared.
- the production capacity of the continuous production apparatus is about 3500 [kg / hr], and the above steps may be one series or two series or more, respectively. In the case of two or more series, the production capacity is indicated by the total amount of each series.
- polyacrylic acid (salt) -based water absorbent resin powder was produced continuously.
- the monomer aqueous solution (1) adjusted to 40 ° C. was continuously supplied with a metering pump, and then 97.1 parts by weight of a 48 wt% sodium hydroxide aqueous solution was continuously line-mixed. At this time, the temperature of the aqueous monomer solution (1) increased to 85 ° C. due to heat of neutralization.
- the band-like hydrogel (1) has a CRC of 28.1 [g / g], a resin solid content of 53.1% by weight, a water-soluble component of 4.1% by weight, and a water-soluble component weight average molecular weight of 21.8 ⁇ . 10 4 [Da].
- the band-shaped hydrogel (1) is continuously cut at equal intervals so as to have a cut length of about 300 mm in the width direction with respect to the traveling direction of the polymerization belt, and the cut hydrogel (1) ( In this specification, “cut water-containing gel (1)” was also obtained.
- Production Example 2 The production amount of polyethylene glycol diacrylate (average n number; 9) in Production Example 1 was changed to 1.05 parts by weight, and the same operation was performed to obtain a strip-shaped hydrogel (2) and a cut hydrous gel (2). Obtained.
- the band-like hydrogel (2) has a CRC of 28.6 [g / g], a resin solid content of 53.0% by weight, a water-soluble content of 4.2% by weight, and a water-soluble content of a weight average molecular weight of 26.2 ⁇ . 10 4 [Da].
- Production Example 3 The production amount of polyethylene glycol diacrylate (average n number; 9) in Production Example 1 was changed to 0.84 parts by weight, and the same operation was performed to obtain a strip-like hydrogel (3) and a cut hydrous gel (3). Obtained.
- the band-like hydrogel (3) has a CRC of 30.2 [g / g], a resin solid content of 53.0% by weight, a water-soluble component of 4.9% by weight, and a water-soluble component weight-average molecular weight of 35.4 ⁇ . 10 4 [Da].
- Production Example 4 The production amount of polyethylene glycol diacrylate (average n number; 9) in Production Example 1 was changed to 0.31 part by weight, and the same operation was performed to obtain a strip-shaped hydrous gel (4) and a cut hydrous gel (4). Obtained.
- the band-shaped hydrogel (4) has a CRC of 41.3 [g / g], a resin solid content of 52.8% by weight, a water-soluble content of 8.0% by weight, and a weight-average molecular weight of water-soluble content of 73.6 ⁇ . 10 4 [Da].
- the amount of polyethylene glycol diacrylate (average n number: 9) used in Production Example 1 was 1.05 parts by weight, and 52 parts by weight of 0.1 wt% ethylenediaminetetra (methylenephosphonic acid) 5 sodium aqueous solution was 45 wt% diethylenetriamine. The amount was changed to 0.026 parts by weight of an aqueous solution of pentasodium triacetate. Also, the amount of deionized water used was changed from 134 parts by weight to 185 parts by weight, and 0.20 part by weight of a 10% by weight polyoxyethylene (20) sorbitan monostearate (manufactured by Kao Corporation) solution was added to the monomer aqueous solution. did. Further, 0.122 parts by weight of nitrogen gas was continuously line-mixed from another charging point simultaneously with the 4% by weight sodium persulfate aqueous solution.
- the band-shaped hydrogel (5) has a CRC of 27.2 [g / g], a resin solid content of 53.5% by weight, a water-soluble component of 4.0% by weight, and a water-soluble component weight average molecular weight of 27.8 ⁇ . 10 4 [Da].
- the band-shaped hydrogel (5) is continuously cut at equal intervals so that the cut length is about 200 mm in the width direction with respect to the traveling direction of the polymerization belt, and the cut hydrogel (5) ( In this specification, “cut water-containing gel (5)” was also obtained.
- Production Example 7 The production amount of polyethylene glycol diacrylate (average n number; 9) in Production Example 1 was changed to 0.49 parts by mass, and the same operation was performed to obtain a strip-shaped hydrous gel (7) and a cut hydrous gel (7). Obtained.
- Table 1 and Table 2 show the screw shape and barrel shape of the gel crusher used in Examples and Comparative Examples, respectively.
- the cut hydrous gel (1) is supplied at 360 [g / min] (60 g of gel is charged every 10 seconds).
- a comparative particulate water-containing gel (1) was obtained.
- the gel grinding energy (2) (GGE (2)) was 20.5 [J / g]
- the treatment inner diameter ratio T / N 3 was 0.11 [g / hr / mm 3 ].
- the comparative particulate water-containing gel (1) was spread on a drying net of a hot air dryer.
- the temperature of the comparative particulate hydrogel (1) at this time was 80 ° C.
- drying was performed at 190 ° C. for 30 minutes to obtain a comparative dry polymer (1).
- the average wind speed of the hot air of the hot air dryer was 1.0 [m / s] in the direction perpendicular to the plane of the drying net.
- the wind speed of the hot air was measured using a constant temperature thermal anemometer Anemomaster 6162 manufactured by Nippon Kanomax Co., Ltd.
- the entire amount of the comparative dry polymer (1) of about 30 ° C. (after cooling) obtained in the drying step was supplied to a roll mill and pulverized (pulverization step), and then further JIS having openings of 710 ⁇ m and 150 ⁇ m. Particles larger than 170 ⁇ m and particles smaller than 150 ⁇ m were removed using a standard sieve to obtain comparatively pulverized comparative water-absorbent resin particles (1).
- the surface cross-linking agent solution was uniformly mixed and heat-treated at 208 ° C. for about 40 minutes. Thereafter, cooling is performed, from 1.17 parts by weight of 27.5% by weight aluminum sulfate aqueous solution (8% by weight in terms of aluminum oxide), 0.196 parts by weight of 60% by weight sodium lactate aqueous solution and 0.029 parts by weight of propylene glycol.
- the resulting (ion binding) surface crosslinker solution was mixed uniformly.
- comparative water absorbent resin particles (1) and comparative water absorbent resin powder (1) were crushed (size-regulating step) until it passed through a JIS standard sieve having a mesh size of 710 ⁇ m to obtain comparative water absorbent resin particles (1) and comparative water absorbent resin powder (1).
- Table 3 shows properties of the comparative water absorbent resin powder (1)
- Table 6 shows properties of the comparative water absorbent resin particles (1)
- other properties of the comparative water absorbent resin powder (1) Table 7 shows the results of thermal conductivity measurement, apparent loss calorie measurement, impact resistance test, and other absorption performance measurements of the comparative water absorbent resin powder (1).
- Example 1 The cut hydrous gel (2) obtained in Production Example 2 was supplied to the gel crusher according to the present invention, and the gel was crushed.
- the screw and barrel of the above-mentioned gel crusher the screw Nos. Listed in Table 1 were used. S86-435 and the barrel No. described in Table 2 B88-478 was used. And operation similar to the comparative example 2 was performed, and the particulate water-containing gel (1), the water absorbing resin particle (1), and the water absorbing resin powder (1) were obtained.
- the gel grinding energy (2) (GGE (2)) at this time was 7.7 [J / g].
- Table 3 shows the cross-sectional area ratio B / A of the screw of the gel crusher, the screw flight width inner diameter ratio F / N, and various physical properties of the water absorbent resin powder (1). Further, Table 6 shows various physical properties of the water absorbent resin particles (1) and other physical properties of the water absorbent resin powder (1).
- Example 2 The cut hydrous gel (2) obtained in Production Example 2 was supplied to the gel crusher according to the present invention, and the gel was crushed.
- the screw and barrel of the above-mentioned gel crusher the screw Nos. Listed in Table 1 were used. S86-4310 and the barrel No. described in Table 2 B88-478 was used. And operation similar to the comparative example 2 was performed, and the particulate water-containing gel (2), the water-absorbent resin particle (2), and the water-absorbent resin powder (2) were obtained.
- the gel grinding energy (2) (GGE (2)) at this time was 7.7 [J / g].
- Table 3 shows the cross-sectional area ratio B / A of the screw of the gel crusher, the screw flight width inner diameter ratio F / N, and various physical properties of the water absorbent resin powder (2).
- Table 6 shows properties of the water absorbent resin particles (2) and other properties of the water absorbent resin powder (2).
- Example 3 The cut hydrous gel (2) obtained in Production Example 2 was supplied to the gel crusher according to the present invention, and the gel was crushed.
- the screw and barrel of the above-mentioned gel crusher the screw Nos. Listed in Table 1 were used. S86-443 and the barrel No. described in Table 2 B88-478 was used. And operation similar to the comparative example 2 was performed, and the particulate water-containing gel (3), the water absorbing resin particle (3), and the water absorbing resin powder (3) were obtained.
- the gel grinding energy (2) (GGE (2)) at this time was 8.9 [J / g].
- Table 3 shows the cross-sectional area ratio B / A of the screw of the gel crusher, the screw flight width inner diameter ratio F / N, and various physical properties of the water absorbent resin powder (3).
- Table 6 shows properties of the water absorbent resin particles (3) and other properties of the water absorbent resin powder (3).
- Example 4 The cut hydrous gel (2) obtained in Production Example 2 was supplied to the gel crusher according to the present invention, and the gel was crushed.
- the screw and barrel of the above-mentioned gel crusher the screw Nos. Listed in Table 1 were used. S86-445 and the barrel No. described in Table 2 B88-478 was used. And operation similar to the comparative example 2 was performed, and the particulate water-containing gel (4), the water absorbing resin particle (4), and the water absorbing resin powder (4) were obtained.
- the gel grinding energy (2) (GGE (2)) at this time was 8.8 [J / g].
- Table 3 shows the cross-sectional area ratio B / A of the screw of the gel crusher, the screw flight width inner diameter ratio F / N, and various physical properties of the water absorbent resin powder (4).
- Table 6 shows properties of the water absorbent resin particles (4) and other properties of the water absorbent resin powder (4).
- Example 5 The cut hydrous gel (2) obtained in Production Example 2 was supplied to the gel crusher according to the present invention, and the gel was crushed.
- the screw and barrel of the above-mentioned gel crusher the screw Nos. Listed in Table 1 were used. S86-4410 and the barrel No. described in Table 2 B88-478 was used. And operation similar to the comparative example 2 was performed, and the particulate water-containing gel (5), the water absorbing resin particle (5), and the water absorbing resin powder (5) were obtained.
- the gel grinding energy (2) (GGE (2)) at this time was 8.7 [J / g].
- Table 3 shows the cross-sectional area ratio B / A of the screw of the gel crusher, the screw flight width inner diameter ratio F / N, and various physical properties of the water absorbent resin powder (5).
- Table 6 shows properties of the water absorbent resin particles (5) and other properties of the water absorbent resin powder (5).
- Example 6 The cut hydrous gel (2) obtained in Production Example 2 was supplied to the gel crusher according to the present invention, and the gel was crushed.
- the screw and barrel of the above-mentioned gel crusher the screw Nos. Listed in Table 1 were used. S86-463 and the barrel No. described in Table 2 B88-478 was used. And operation similar to the comparative example 2 was performed, and the particulate water-containing gel (6), the water absorbent resin particle (6), and the water absorbent resin powder (6) were obtained.
- the gel grinding energy (2) (GGE (2)) at this time was 13.5 [J / g].
- Table 3 shows the cross-sectional area ratio B / A of the screw of the gel crusher, the screw flight width inner diameter ratio F / N, and various physical properties of the water absorbent resin powder (6).
- Table 6 shows properties of the water absorbent resin particles (6) and other properties of the water absorbent resin powder (6).
- Example 7 The cut hydrous gel (2) obtained in Production Example 2 was supplied to the gel crusher according to the present invention, and the gel was crushed.
- the screw and barrel of the above-mentioned gel crusher the screw Nos. Listed in Table 1 were used. S86-465 and the barrel No. described in Table 2 B88-478 was used. And operation similar to the comparative example 2 was performed, and the particulate water-containing gel (7), the water absorbing resin particle (7), and the water absorbing resin powder (7) were obtained.
- the gel grinding energy (2) (GGE (2)) at this time was 13.4 [J / g].
- Table 3 shows the cross-sectional area ratio B / A of the screw of the gel crusher, the screw flight width inner diameter ratio F / N, and various physical properties of the water absorbent resin powder (7).
- Table 6 shows properties of the water absorbent resin particles (7) and other properties of the water absorbent resin powder (7).
- Example 8 The cut hydrous gel (2) obtained in Production Example 2 was supplied to the gel crusher according to the present invention, and the gel was crushed.
- the screw and barrel of the above-mentioned gel crusher the screw Nos. Listed in Table 1 were used. S86-4610 and barrel No. B88-478 was used. And operation similar to the comparative example 2 was performed, and the particulate water-containing gel (8), the water absorbent resin particle (8), and the water absorbent resin powder (8) were obtained.
- the gel grinding energy (2) (GGE (2)) at this time was 13.3 [J / g].
- Table 3 shows the cross-sectional area ratio B / A of the screw of the gel crusher, the screw flight width inner diameter ratio F / N, and various physical properties of the water absorbent resin powder (8).
- Table 6 shows properties of the water absorbent resin particles (8) and other properties of the water absorbent resin powder (8).
- Example 9 The cut hydrous gel (2) obtained in Production Example 2 was supplied to the gel crusher according to the present invention, and the gel was crushed.
- the screw and barrel of the above-mentioned gel crusher the screw Nos. Listed in Table 1 were used. S130-4710 and barrel No. 2 listed in Table 2. B136-6810 was used. Further, a perforated plate having a diameter of 160 mm, a die hole diameter of 16 mm, and a die thickness of 14 mm was mounted on the gel crusher. Table 3 shows the cross-sectional area ratio B / A and screw flight width inner diameter ratio F / N of the screw of the gel crusher.
- the obtained particulate hydrogel (9) was subjected to the same operations as in Comparative Example 1 (drying, pulverization, classification, surface cross-linking, etc.) to obtain water absorbent resin particles (9) and water absorbent resin powder (9).
- Table 3 shows properties of the water absorbent resin powder (9).
- Table 6 shows properties of the water absorbent resin particles (9) and other properties of the water absorbent resin powder (9).
- Example 10 The cut hydrous gel (2) obtained in Production Example 2 was supplied to the gel crusher according to the present invention, and the gel was crushed.
- the screw and barrel of the above-mentioned gel crusher the screw Nos. Listed in Table 1 were used. S175-51017 and the barrel No. described in Table 2. B181-71520 was used.
- a porous plate having a diameter of 220 mm, a die hole diameter of 16 mm, and a die thickness of 25 mm was mounted on the gel crusher.
- Table 3 shows the cross-sectional area ratio B / A and screw flight width inner diameter ratio F / N of the screw of the gel crusher.
- the obtained particulate hydrogel (10) was subjected to the same operations as in Comparative Example 1 (drying, pulverization, classification, surface cross-linking, etc.) to obtain water absorbent resin particles (10) and water absorbent resin powder (10).
- Table 3 shows properties of the water absorbent resin powder (10).
- Table 6 shows properties of the water absorbent resin particles (10) and other properties of the water absorbent resin powder (10).
- Table 4 shows the cross-sectional area ratio B / A, screw flight width inner diameter ratio F / N, and various properties of the comparative water absorbent resin powder (3) of the gel crusher.
- Table 6 shows properties of the comparative water absorbent resin particles (3) and other physical properties of the comparative water absorbent resin powder (3).
- Table 7 shows the results of thermal conductivity measurement, apparent loss calorie measurement, impact resistance test, and other absorption performance measurements of the comparative water absorbent resin powder (3).
- Example 11 The cut hydrous gel (3) obtained in Production Example 3 was supplied to the gel crusher according to the present invention, and the gel was crushed.
- the screw and barrel of the above-mentioned gel crusher the screw Nos. Listed in Table 1 were used. S86-445 and the barrel No. described in Table 2 B88-478 was used. And operation similar to the comparative example 2 was performed, and the particulate water-containing gel (11), the water-absorbent resin particle (11), and the water-absorbent resin powder (11) were obtained.
- the gel grinding energy (2) (GGE (2)) at this time was 9.4 [J / g].
- Table 4 shows the cross-sectional area ratio B / A of the screw of the gel crusher, the screw flight width inner diameter ratio F / N, and various physical properties of the water absorbent resin powder (11).
- Table 6 shows properties of the water absorbent resin particles (11) and other properties of the water absorbent resin powder (11).
- Table 5 shows the cross-sectional area ratio B / A, screw flight width inner diameter ratio F / N, and various properties of the comparative water absorbent resin powder (4) of the gel crusher.
- Table 6 shows properties of the comparative water absorbent resin particles (4) and other physical properties of the comparative water absorbent resin powder (4).
- Table 7 shows the results of thermal conductivity measurement, apparent loss calorimetry, impact resistance test, and other absorption performance measurements of the comparative water absorbent resin powder (4).
- Water absorbent resin powder (compared with water absorbent resin powder (5)), which was taken out from paper diapers purchased in Japan in May 2013 (Procter & Gamble Japan Co., Ltd .: trade name “Pampers Sarasara Care Pants”) Water absorbent resin powder (referred to as comparative water absorbent resin powder (6)) taken out from paper diapers (manufactured by SCA: trade name “Drypers WeeWEE DRY”) purchased in October 2010 in Thailand, July 2012 Water-absorbent resin powder (referred to as comparative water-absorbent resin powder (7)) taken out from paper diapers purchased in Thailand in the month of March (Dao Paper Co., Ltd .: trade name “GOO.
- Example 12 The cut hydrous gel (4) obtained in Production Example 4 was supplied to the gel crusher according to the present invention, and gel crushed.
- the screw and barrel of the above-mentioned gel crusher the screw Nos. Listed in Table 1 were used. S86-445 and the barrel No. described in Table 2 B88-478 was used. And operation similar to the comparative example 2 was performed, and the particulate water-containing gel (12), the water-absorbent resin particle (12), and the water-absorbent resin powder (12) were obtained.
- the gel grinding energy (2) (GGE (2)) at this time was 11.4 [J / g].
- Table 5 shows the cross-sectional area ratio B / A of the screw of the gel crusher, the screw flight width inner diameter ratio F / N, and various physical properties of the water absorbent resin powder (12). Further, Table 6 shows various physical properties of the water absorbent resin particles (12) and other physical properties of the water absorbent resin powder (12).
- Example 13 The cut hydrous gel (5) obtained in Production Example 5 was supplied to the gel crusher according to the present invention and gel crushed.
- the screw and barrel of the above-mentioned gel crusher the screw Nos. Listed in Table 1 were used. S86-4410 and the barrel No. described in Table 2 B88-478 was used. And operation similar to the comparative example 2 was performed, and the particulate water-containing gel (13), the water absorbing resin particle (13), and the water absorbing resin powder (13) were obtained.
- the gel grinding energy (2) (GGE (2)) at this time was 9.8 [J / g].
- Table 3 shows the cross-sectional area ratio B / A of the screw of the gel crusher, the screw flight width inner diameter ratio F / N, and various physical properties of the water absorbent resin powder (13).
- Table 6 shows properties of the water absorbent resin particles (13) and other properties of the water absorbent resin powder (13).
- Example 14 The same operation as in Example 1 was changed from 10.64 [kg / min] to 17.2 [kg / min] (injecting 430 g of gel every 1.5 seconds). Thus, a particulate hydrogel (14), water absorbent resin particles (14) and a water absorbent resin powder (14) were obtained.
- the gel grinding energy (2) (GGE (2)) was 4.5 [J / g]
- the treatment inner diameter ratio T / N 3 was 1.51 [g / hr / mm 3 ].
- Table 3 shows the cross-sectional area ratio B / A of the screw of the gel crusher, the screw flight width inner diameter ratio F / N, and various physical properties of the water absorbent resin powder (14).
- Table 6 shows properties of the water absorbent resin particles (14) and other properties of the water absorbent resin powder (14).
- the water absorbent resin powders (1) and (2) produced in Examples 1 and 2 using the gel crusher according to the present invention having a screw satisfying 0.034 ⁇ F / N ⁇ 0.20 are: Compared with the comparative water-absorbent resin powders (1) and (2) produced in Comparative Examples 1 and 2, the physical properties of water absorption capacity under pressure (AAP) and liquid permeability (SFC) are improved. I understand.
- the water-absorbing resin powders (4), (5), (7) to (10) produced in No. 10 are the comparative water-absorbing resin powders (1) and (2) produced in Comparative Examples 1 and 2, respectively. In comparison, it can be seen that the physical properties of water absorption under pressure (AAP) and liquid permeability (SFC) are improved. Further, manufactured in Example 11 using the gel grinding apparatus according to the present invention having a screw satisfying both 0.034 ⁇ F / N ⁇ 0.20 and 0.215 ⁇ B / A ⁇ 0.630.
- the water absorbent resin powder (11) thus produced has both physical properties of water absorption capacity under pressure (AAP) and liquid permeability (SFC). It can be seen that there is a marked improvement. Further, manufactured in Example 12 using the gel grinding apparatus according to the present invention having a screw satisfying both 0.034 ⁇ F / N ⁇ 0.20 and 0.215 ⁇ B / A ⁇ 0.630. Compared with the comparative water absorbent resin powder (4) produced in Comparative Example 4, the water absorbent resin powder (12) thus produced has remarkable physical properties of both water absorption capacity under pressure (AAP) and water absorption speed (FSR). It can be seen that there is an improvement.
- AAP water absorption capacity under pressure
- FSR water absorption speed
- the physical property of liquid permeability (SFC) is improved here, indicating a high SFC when comparing the SFC values of water-absorbent resin powders having the same CRC, and When the CRC value of the water-absorbent resin powder having SFC is compared, the high CRC is indicated.
- Example 15 The cut hydrous gel (6) obtained in Production Example 6 was supplied to the gel crusher of the present application and subjected to gel crushing.
- the screw and barrel of the above-mentioned gel crusher the screw Nos. Listed in Table 1 were used. S86-445 and the barrel No. described in Table 2 B88-478 was used.
- a perforated plate mounted on the gel crusher a plate having a diameter of 100 mm, a die hole diameter of 9.5 mm, and a die thickness of 10 mm was used. And operation similar to the comparative example 2 was performed, and the obtained particulate hydrogel (15) was spread
- the temperature of the particulate hydrogel (15) at this time was 80 ° C. After spraying, drying was performed at 190 ° C. for 30 minutes to obtain a dry polymer (15).
- the average wind speed of the hot air of the hot air dryer was 1.0 [m / s] in the direction perpendicular to the plane of the drying net. The wind speed of the hot air was measured using a constant temperature thermal anemometer Anemomaster 6162 manufactured by Nippon Kanomax Co., Ltd.
- the entire amount of the dried polymer (15) at about 30 ° C. (after cooling) obtained in the drying step was pulverized by continuously supplying it to a three-stage roll mill to obtain a pulverized polymer (15).
- the roll gap of this three-stage roll mill was 0.8 mm / 0.65 mm / 0.48 mm in order from the top.
- the degree of vacuum in the pulverization step was 0.29 kPa.
- the obtained pulverized polymer (15) (about 60 ° C.) was sieved using a sieving apparatus having a mesh screen of 710 ⁇ m and 175 ⁇ m, Particles (A) that did not pass through the 710 ⁇ m sieve, particles (B) that passed through the 710 ⁇ m sieve but did not pass through the 175 ⁇ m sieve (B), and particles (C) that passed through the 175 ⁇ m sieve were continuously classified.
- the particles (A) that did not pass through the 710 ⁇ m sieve were again supplied to a three-stage roll mill and pulverized.
- the degree of vacuum in the classification step was 0.11 kPa, and air having a dew point of 10 ° C. and a temperature of 75 ° C. was passed through the sieve apparatus at 2 [m 3 / hr].
- an oscillating circular sieving device (frequency: 230 rpm, radial inclination (gradient): 11 mm, tangential inclination (gradient): 11 mm, eccentricity: 35 mm, apparatus temperature: 55 ° C.)
- the gantry on which the sieving device was installed was grounded (static elimination) with a grounding resistance value of 5 ⁇ .
- the mixture was crushed (granulation step) until it passed through a JIS standard sieve having an aperture of 710 ⁇ m to obtain a water absorbent resin powder (15).
- the mass average particle size (D50) was 363 ⁇ m
- the logarithmic standard deviation ( ⁇ ) of the particle size distribution was 0.37
- the 710 ⁇ m non-passing particles (mesh of 710 ⁇ m opening)
- the ratio of the particles that do not pass through the screen is 0% by mass
- the particle size of 710 ⁇ m to 600 ⁇ m (the ratio of the particles that pass through the sieve having an aperture of 710 ⁇ m and does not pass through the sieve having an aperture of 600 ⁇ m) is 4.2% by mass
- the particles of 500 ⁇ m are 15.8% by mass
- the particles of 500 ⁇ m to 300 ⁇ m are 48.9% by mass
- the particles of 300 ⁇ m to 150 ⁇ m are 30.0% by mass
- Example 16 The same operation as in Example 15 was performed by changing the cut hydrous gel (6) to the cut hydrogel (7) obtained in Production Example 7 to obtain a water absorbent resin powder (16).
- the mass average particle size (D50) was 376 ⁇ m
- the logarithmic standard deviation ( ⁇ ) of the particle size distribution was 0.34
- 500 ⁇ m non-passing particles was 21.6% by mass.
- the surface tension of the water absorbent resin powder (16) was 72.0 [mN / m].
- Table 7 shows physical properties relating to thermal conductivity, apparent heat loss, impact resistance test, and other absorption performance.
- Example 17 The same operation as in Example 15 was performed by changing the cut water-containing gel (6) to the cut water-containing gel (4) obtained in Production Example 4 to obtain a water absorbent resin powder (17).
- the particle size distribution of the water absorbent resin powder (17) was measured, the mass average particle size (D50) was 333 ⁇ m, the logarithmic standard deviation ( ⁇ ) of the particle size distribution was 0.33, and 500 ⁇ m non-passing particles (aperture 500 ⁇ m). The ratio of particles not passing through the sieve was 19.9% by mass.
- the surface tension of the water absorbent resin powder (17) was 73 [mN / m]. Table 7 shows physical properties relating to thermal conductivity, apparent heat loss, impact resistance test, and other absorption performance.
- Example 18 The same operation as in Example 17 was performed by changing the hole diameter of the die used at the time of gel pulverization to 7.5 mm to obtain a water absorbent resin powder (18).
- the mass average particle size (D50) was 331 ⁇ m
- the logarithmic standard deviation ( ⁇ ) of the particle size distribution was 0.31
- 500 ⁇ m non-passing particles was 0.31
- the ratio of particles not passing through the sieve was 24.3 mass%.
- the surface tension of the water absorbent resin powder (18) was 72 [mN / m].
- Table 7 shows physical properties relating to thermal conductivity, apparent heat loss, impact resistance test, and other absorption performance.
- Example 19 1,100 parts by weight of 1,4-butanediol, 0.6 parts by weight of propylene glycol and 3.0 parts by weight of deionized water with respect to 100 parts by weight of the water absorbent resin powder (15) obtained in Example 15. (Covalent bonding) surface cross-linking agent solution consisting of the above is uniformly mixed and heated at 208 ° C. for about 30 minutes so that the resulting water-absorbent resin surface cross-linked particles (19) have a CRC of about 34 [g / g]. Processed.
- the mixture was pulverized (granulation step) until it passed through a JIS standard sieve having a mesh size of 710 ⁇ m to obtain water-absorbing resin surface-crosslinked particles (19) having a cross-linked surface.
- 100 parts by mass of the water-absorbing tree surface crosslinked particles (19) thus obtained are dry-stirred and mixed with 0.5 parts by mass of water-insoluble inorganic fine particles (Aerosil 200; manufactured by Nippon Aerosil Co., Ltd.), so that the surface is water-insoluble inorganic fine particles.
- Water-absorbent resin powder (19) coated with was obtained.
- the surface tension, mass average particle diameter (D50), logarithmic standard deviation of particle size distribution ( ⁇ ), 500 ⁇ m non-passing particles (ratio of particles that do not pass through a sieve having an opening of 500 ⁇ m) are: The value was almost the same as that of the water absorbent resin powder (15) of Example 15.
- Table 7 shows physical properties relating to thermal conductivity, apparent heat loss, impact resistance test, and other absorption performance.
- Example 20 Surface consisting of 0.015 parts by mass of ethylene glycol diglycidyl ether, 1.0 part by mass of propylene glycol and 3.0 parts by mass of water with respect to 100 parts by mass of the water absorbent resin powder (15) obtained in Example 15
- the treating agent was mixed uniformly and heat-treated at 100 ° C. for 45 minutes.
- the surface-crosslinked water-absorbent resin surface particles (20) were obtained by sizing with a JIS standard sieve having an opening of 710 ⁇ m.
- kaolin product name Neogen 2000, manufactured by Dry Brab Kaolin Company
- Example 21 1.5 g of pulp was uniformly mixed with 30 g of the water absorbent resin powder (18) obtained in Example 18 to obtain a mini absorbent body. With respect to this mini-absorber, the amount of heat lost to the absorber was measured with the apparatus shown in FIG. The results are shown in Table 8. However, the top sheet and the back sheet were taken from Unicharm Corporation, trade name Mummy Pokotape type, L size (purchased in Japan in February 2014). The top sheet is a sheet made of non-woven fabric and paper disposed on the most wearer side, and the back sheet is a water-impermeable material on the opposite side of the top sheet with the absorbent body in between.
- Example 9 The same operation as in Example 21 was performed using 30 g of the comparative water absorbent resin powder (1) obtained in Comparative Example 1 to obtain a mini absorbent body. Absorber loss calorie was measured for this mini absorber. The results are shown in Table 8.
- the water-absorbent resin powder according to the present invention has an absorption capacity under pressure (AAP), water absorption performance (CRC), and liquid permeability (SFC), and 150 ⁇ m after the impact resistance test. It can be seen that there are few particles less than that, and has an appropriate internal cell ratio, and the thermal conductivity is small, so that the apparent heat loss is small.
- AAP absorption capacity under pressure
- CRC water absorption performance
- SFC liquid permeability
- Gel pulverizing apparatus according to the present invention, polyacrylic acid (salt) water-absorbing resin powder manufacturing method according to the present invention, and water-absorbing resin powder are used for sanitary purposes such as paper diapers, sanitary napkins and medical blood-collecting agents. Useful for supplies. Also, pet urine absorbent, urine gelling agent for portable toilets and freshness-preserving agent such as fruits and vegetables, drip absorbent for meat and seafood, cold insulation, disposable warmer, gelling agent for batteries, water retention agent for plants and soil It can also be used in various applications such as anti-condensation agents, water-stopping agents and packing agents, and artificial snow.
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Abstract
Description
(1)0.215≦B/A≦0.630
(2)0.034<F/N≦0.20。
(A)耐衝撃試験前の150μm未満の粒子割合が0質量%~4.5質量%であり、耐衝撃試験により増加する150μm未満の粒子割合が0質量%~4.5質量%
(B)加圧下吸収倍率(AAP)が17以上
(C)熱伝導率が125[mW/(m・K)]以下
を満たす吸水性樹脂粉末。
(内部気泡率)[%]={(真密度)-(見かけ密度)}/(真密度)×100
で規定される内部気泡率が0~3.7%であることを特徴とする〔1-1〕及び〔1-2〕の何れか一項に記載の吸水性樹脂粉末。
(1-1)「吸水性樹脂」
本発明における「吸水性樹脂」とは、水膨潤性水不溶性の高分子ゲル化剤を意味する。ここで、「水膨潤性」とは、ERT442.2-02にて規定されるCRC(無加圧下吸水倍率)が5[g/g]以上であることをいい、「水不溶性」とは、ERT470.2-02にて規定されるExt(水可溶分)が0~50重量%であることをいう。
本発明における「ポリアクリル酸(塩)」とは、グラフト成分を必要に応じて含んでおり、繰り返し単位として、アクリル酸、その塩(本明細書中では両者をまとめて「アクリル酸(塩)」と称する)、又はその組み合わせを主成分とする重合体を意味する。具体的には、本発明における「ポリアクリル酸(塩)」は、重合に用いられる総単量体(内部架橋剤を除く)のうち、アクリル酸(塩)を必須に50~100モル%、好ましくは70~100モル%、更に好ましくは90~100モル%、特に好ましくは実質100モル%含む重合体をいう。又、重合体としてポリアクリル酸(塩)を用いる場合は、水溶性塩を必ず含んでおり、上記水溶性塩(中和塩)の主成分としては、一価の塩が好ましく、アルカリ金属塩又はアンモニウム塩がより好ましく、アルカリ金属塩が更に好ましく、ナトリウム塩が特に好ましい。
「EDANA」とは、欧州不織布工業会(European Disposables and Nonwovens Associations) の略称であり、「ERT」とは、欧州標準(ほぼ世界標準)である吸水性樹脂の測定方法(EDANA Recommended Test Methods)の略称である。尚、本発明においては、特に断りのない限り、ERT原本(公知文献:2002年改定)に準拠して測定を行う。
「CRC」は、Centrifuge Retention Capacity (遠心分離機保持容量)の略称であり、無加圧下吸水倍率(本明細書中にて「吸水倍率」と称する)を意味する。具体的に「CRC」とは、不織布袋中の0.200gの吸水性樹脂を、大過剰の0.9重量%塩化ナトリウム水溶液に対して30分間自由膨潤させ、遠心分離機を用いて水切りした後の吸水性樹脂の吸水倍率(単位;[g/g])をいう。
「AAP」とは、Absorption Against Pressure の略称であり、加圧下吸水倍率を意味する。具体的に「AAP」とは、0.900gの吸水性樹脂を、0.9重量%塩化ナトリウム水溶液に対して1時間にわたって、2.06kPa(0.3psi、21[g/cm2])の荷重下にて膨潤させた後の吸水性樹脂の吸水倍率(単位;[g/g])をいう。尚、ERT442.2-02では、Absorption Under Pressure と表記されているが、実質的に同一内容である。又、本明細書中に記載の測定では、荷重条件を4.83kPa(0.7psi、49[g/cm2])に変更して行う。
「Ext」とは、Extractable の略称であり、水可溶分(水可溶成分量)を意味する。具体的に「Ext」とは、1.000gの吸水性樹脂を0.9重量%塩化ナトリウム水溶液200mLに添加し、16時間にわたって攪拌した後の溶解ポリマー量(単位;重量%)をいう。上記溶解ポリマー量の測定は、pH滴定を用いて行う。
「PSD」とは、Particle Size Distributionの略称であり、篩分級により測定される粒度分布を意味する。尚、重量平均粒子径(D50)及び粒子径分布幅は、欧州特許第0349240号の明細書7頁25~43行に記載された「(1) Average Particle Diameter and Distribution of Particle Diameter」と同様の方法で測定する。尚、含水ゲル状架橋重合体のPSDの測定方法については後述する。又、粒度測定にて使用する標準篩(目開き)は、対象物の粒度によって適宜追加してもよい。例えば、目開きが710μm、600μm等の標準篩を追加すればよい。又、上記欧州特許第0349240号に開示のない測定条件等については、欧州特許第1594556号を適宜参照してもよい。
「Residual Monomers」は、吸水性樹脂中に残存する単量体(モノマー)量(本明細書中にて「残存モノマー」と称する)を意味する。具体的に「Residual Monomers」とは、1.0gの吸水性樹脂を0.9重量%塩化ナトリウム水溶液200mLに添加し、35mmのスターラーチップを用いて500rpmで1時間にわたって攪拌した後の溶解したモノマー量(単位;ppm)をいう。溶解モノマー量の測定は、HPLC(高速液体クロマトグラフィー)を用いて行う。尚、含水ゲル状架橋重合体の残存モノマーは、試料を2g、攪拌時間を3時間にそれぞれ変更して測定を行い、得られた測定値を含水ゲル状架橋重合体の樹脂固形分当りの重量に換算した値(単位;ppm)とする。
「Moisture Content」は、吸水性樹脂の含水率を意味する。具体的に「Moisture Content」とは、吸水性樹脂1gを105℃で3時間にわたって乾燥させたときの乾燥減量から算出した値(単位;重量%)である。尚、本発明では乾燥温度を180℃に変更し、測定は1サンプルにつき5回行い、その平均値を採用する。又、含水ゲル状架橋重合体の含水率は、試料を2g、乾燥温度を180℃、乾燥時間を16時間にそれぞれ変更して測定を行う。更に、{100-含水率(重量%)}で算出される値を、本発明では「樹脂固形分」とし、吸水性樹脂及び含水ゲル状架橋重合体の双方に適用することができる。
「Density」は、吸水性樹脂の嵩比重を意味する。具体的に「Density」とは、吸水性樹脂100gをEDANA規定の装置に投入し、100mL容器に、該吸水性樹脂を自由落下させて充填させたときの、吸水性樹脂の重量(単位;[g/mL])をいう。
「Flow Rate」は、吸水性樹脂の流下速度を意味する。具体的に「Flow Rate」とは、吸水性樹脂100gをEDANA規定の装置に投入し、該装置最下部の排出口から吸水性樹脂を排出する場合、その排出に要した時間(単位;sec)をいう。
本発明における「通液性」とは、荷重下又は無荷重下における膨潤ゲルの粒子間を通過する液の流れ性のことをいう。代表的な通液性の測定方法としては、SFC(Saline Flow Conductivity/食塩水流れ誘導性)、又はGBP(Gel Bed Permeability/ゲル床透過性)がある。
本発明における「FSR」とは、Free Swell Rate の略称であり、吸水速度(自由膨潤速度)を意味する。具体的に「FSR」とは、吸水性樹脂1gが0.9重量%塩化ナトリウム水溶液20gを吸水するときの速度(単位;[g/(g・s)])をいう。
本発明における「ゲル粉砕」とは、重合工程(好ましくは水溶液重合、無攪拌水溶液重合(静置水溶液重合)、特に好ましくはベルト重合)にて得られた含水ゲル状架橋重合体を、本発明のゲル粉砕装置を用いて、重合体の大きさを小さくし、所望の形状に調製する操作のことをいう。具体的には、重合工程で得られた含水ゲル状架橋重合体を本発明のゲル粉砕装置を用いて、ゲル粉砕し、その重量平均粒子径(D50)を300~3,000μm、より好ましくは当該重量平均粒子径(D50)を350~2,000μm、粒度分布の対数標準偏差(σζ)を好ましくは0.2~1.0となるように含水ゲル状架橋重合体をゲル粉砕することをいう。
本発明における「水可溶分の重量平均分子量」とは、吸水性樹脂を水溶媒に添加したときに溶解する成分(水可溶分)の重量平均分子量について、GPC(ゲル浸透クロマトグラフィー)を用いて測定した値(単位;daltons/以下、[Da]と略記する。)をいう。即ち、GPCを用いて、上記(1-3)(c)「Ext」に記載されている測定方法により得た溶液を測定した結果である。尚、含水ゲル状架橋重合体の水可溶分の重量平均分子量の測定は、粒子径を5mm以下、更には1~3mmに細粒化した試料を5.0g、攪拌時間を24時間にそれぞれ変更して行う。
本発明における「ゲル粉砕エネルギー」とは、含水ゲル状架橋重合体をゲル粉砕するときに、ゲル粉砕装置が必要とする単位重量(含水ゲル状架橋重合体の単位重量)あたりの機械的エネルギーをいい、ジャケットを加熱冷却するエネルギー又は投入する水及びスチームのエネルギーは含まない。尚、「ゲル粉砕エネルギー」は、英語表記の「Gel Grinding Energy」 から「GGE」と略称する。上記GGEは、ゲル粉砕装置が三相交流電力で駆動する場合、以下の式(1)
GGE[J/g]={√3×電圧×電流×力率×モーター効率}/
{1秒間にゲル粉砕機に投入される含水ゲル状架橋重合体の重量}
・・・式(1)
によって算出される。
GGE(2)[J/g]=
{√3×電圧×(ゲル粉砕時の電流-空運転時の電流)×力率×モーター効率}/
{1秒間にゲル粉砕機に投入される含水ゲル状架橋重合体の重量}
・・・式(2)
によって算出される。尚、上記GGEと区別するため、上記式(2)により算出されるゲル粉砕エネルギーをGGE(2)と表記する。
本明細書において、範囲を示す「X~Y」は、「X以上、Y以下」を意味する。重量の単位である「t(トン)」は、「Metric ton(メトリック トン)」を意味し、更に、特に注釈のない限り、「ppm」は「重量ppm」を意味する。「重量」と「質量」、「重量%」と「質量%」、「重量部」と「質量部」は同義語として扱う。更に、「~酸(塩)」は「~酸及び/又はその塩」を意味し、「(メタ)アクリル」は「アクリル及び/又はメタクリル」を意味する。又、「主成分」は、全体の51%以上を占めていることを意味する。
本発明に係るゲル粉砕装置は、重合中又は重合後の含水ゲル状架橋重合体を細分化して、所望の形状の含水ゲル状架橋重合体(本明細書中において「粒子状含水ゲル」と称する)を得るために用いる装置である。
図1は、本発明に係るゲル粉砕装置100の全体構成を示す概略の断面図である。ゲル粉砕装置100は、所望の形状の粒子状含水ゲルを得るために用いる装置である。上記ゲル粉砕装置100は、特に、吸水性樹脂の製造において、重合工程と乾燥工程との間に行われるゲル粉砕工程にて用いられる装置である。
図2は、ゲル粉砕装置100の押出口16付近を示す概略の断面図である。スクリュー11は主に、回転軸22及びフライト部23から構成されている。フライト部23は、回転軸22を中心として螺旋状に搭載されている。回転軸22に対するフライト部23の巻き数は、回転軸22の端部からもう一方の端部までに巻かれている数をいう。フライト部の巻き数は特に限定されないが、好ましくは3巻以上であり、特に好ましくは4巻以上である。又、フライト部23は、一重螺旋であっても、二重螺旋であっても、三重螺旋であってもよく、回転軸22に搭載されているフライト部23の数は特に限定されない。
本発明における多孔板12とは、本発明に係るゲル粉砕装置において、バレル13中の含水ゲルが押出される出口部分に備えられている部材である。上記多孔板12の厚さ、孔径又は開孔率は、ゲル粉砕装置の単位時間当りの処理量又は含水ゲルの形状等によって適宜選択することができ、特に限定されないが、多孔板の厚さ(本明細書中において「ダイス厚さ」ともいう)は3.5~40mmが好ましく、8~30mmがより好ましく、10~25mmが最も好ましい。又、多孔板の孔径(本明細書中において「ダイス孔径」ともいう)は、3.2~30mmが好ましく、7.5~25mmがより好ましい。更に、多孔板の開孔率(本明細書中において「ダイス開孔率」ともいう)は、20~80%が好ましく、30~55%がより好ましい。尚、ダイス孔径(mm)が異なる複数の多孔板を使用する場合は、各多孔板の孔径の単純平均値を、ゲル粉砕装置における多孔板の孔径とする。又、当該孔の形状は円形が好ましいが、特に限定されず、円形以外の形状(例えば、四角形、楕円形、スリット形等)の場合には、その開孔面積を円に換算して孔径(mm)とする。
本発明に係るゲル粉砕装置において、軸受け部を備えていてもよい。本明細書中「軸受け部」とは、ダイスのプレートと回転軸との間に備えられる部材をいう。本発明における回転軸22及び軸受け部が接触する部分の材質は、回転軸及び軸受け部の材質と異なることが好ましく、異なる材質の金属であることがより好ましい。回転軸22及び軸受け部と、回転軸22及び軸受け部が接触する部分との材質が同じ場合、焼き付き等による装置の破損や、金属粉の製品への混入のおそれがある。
本発明における回転軸22の回転数は、バレル13の内径によって回転羽根の外周速度が変わるため、一概に規定することはできないが、上記回転軸22の回転数は、60~500rpmが好ましく、80~400rpmがより好ましく、100~200rpmが更に好ましい。上記回転軸22の回転数が60rpm未満の場合、ゲル粉砕に必要なせん断・圧縮力が得られないおそれがある。又、上記回転軸22の回転数が500rpmを超える場合、含水ゲルに与えるせん断・圧縮力が過剰となり、得られる吸水性樹脂の物性の低下を招いたり、本発明に係るゲル粉砕装置に掛かる負荷が大きくなり破損したりするおそれがある。
本発明におけるゲル粉砕装置100の使用時の温度は、含水ゲルの付着等を防ぐために、好ましくは40~120℃、より好ましくは60~100℃であることが好ましい。また、本発明におけるゲル粉砕装置は、加熱装置や保温装置等を有することが好ましい。
本発明に係るゲル粉砕装置に供給されるゲル粉砕前の含水ゲルの温度(本明細書中にて「ゲル温度」ともいう)は、粒度制御や物性の観点から、40~120℃が好ましく、60℃~120℃がより好ましく、60~110℃が更に好ましく、65℃から110℃が特に好ましい。上記ゲル温度が40℃未満の場合、含水ゲルの特性上、硬度及び弾性が増すため、ゲル粉砕時に粒子形状又は粒度分布の制御が困難になるおそれがある。又、上記ゲル温度が120℃を超える場合、含水ゲルの軟度が増し、粒子形状又は粒度分布の制御が困難になるおそれがある。上記ゲル温度は、重合温度又は重合後の加熱、保温或いは冷却等で適宜制御することができる。
本発明に係るゲル粉砕装置の単位時間当たりの処理量は、上記内径Nに依存する値であり、好適な範囲が変化する。本発明に係るゲル粉砕装置の1時間当たりの含水ゲルの処理量をT[g/hr]、上記内径Nを3乗した値をN3[mm3]とするとき、本発明に係るゲル粉砕装置の単位時間当たりの処理量は、処理量内径比T/N3[g/hr/mm3]にて表わすことができる。上記処理量内径比T/N3[g/hr/mm3]の上限は、2.0以下であることが好ましく、1.5以下であることがより好ましく、1.0以下であることが最も好ましい。上記処理量内径比T/N3[g/hr/mm3]の上限が2.0より大きな処理量の場合は、含水ゲルに十分なせん断を加えることができず、目的とする性能が得られないおそれがある。又、上記処理量内径比T/N3[g/hr/mm3]の下限は、0.05以上であることが好ましく、0.10以上であることがより好ましく、0.15以上であることが最も好ましい。上記処理量内径比T/N3[g/hr/mm3]の下限が0.05より小さな処理量の場合は、処理量が少なすぎるため、含水ゲルがゲル粉砕装置内に滞留し、過剰なせん断やゲルの劣化を引き起こすおそれがある。
本発明に係るゲル粉砕装置100において、含水ゲルに水を添加してゲル粉砕することができる。本発明において添加する「水」とは、固体、液体、気体の何れの形態を含むものであってもよい。取扱い性の観点から、液体や気体の形態、或いは液体及び気体の混合形態が好ましい。
上述したように、含水ゲルに水を添加してゲル粉砕することが好ましいが、水以外に他の添加剤又は中和剤等を含水ゲルに添加・混練してゲル粉砕することもでき、得られる吸水性樹脂を改質してもよい。具体的には、ゲル粉砕時に、塩基性物質を含む水溶液(例えば、10~50重量%の水酸化ナトリウム水溶液)を添加して中和してもよいし、吸水性樹脂微粉(0.1~30重量%(対樹脂固形分))を添加して微粉リサイクルを行ってもよい。更に、重合開始剤や還元剤、キレート剤を0.001~3重量%(対樹脂固形分)、ゲル粉砕時に添加・混合して、残存モノマーの低減や着色改善、耐久性を付与してもよい。
本発明に係る吸水性樹脂粉末の製造方法では、ゲル粉砕エネルギー(GGE / Gel Grinding Energy)は一定範囲に制御されることが好ましい。
本発明に係るゲル粉砕装置は、上述した構成を有することにより、高い加圧下吸水倍率の吸水性樹脂粉末を製造することができるという効果を奏する。又、更に熱伝導率が小さい吸水性樹脂を製造することができるという効果を奏する。
(3-1)重合工程
本工程は、アクリル酸(塩)を主成分とする水溶液を重合して、含水ゲル状架橋重合体(本明細書中において「含水ゲル」と称することがある)を得る工程である。
本発明にて得られる吸水性樹脂粉末は、アクリル酸(塩)を主成分として含む単量体を原料として使用し、通常、水溶液状態にて重合される。本明細書中にて、アクリル酸(塩)を主成分として含む単量体の水溶液を、「アクリル酸(塩)系単量体水溶液」とも称する。単量体水溶液中の単量体(モノマー)濃度としては、10~80重量%が好ましく、20~80重量%がより好ましく、30~70重量%が更に好ましく、40~60重量%が特に好ましい。
本発明において、得られる吸水性樹脂粉末の吸水性能の観点から、架橋剤(本明細書中において「内部架橋剤」と称する)を使用することが好ましい。該内部架橋剤としては特に限定されないが、例えば、アクリル酸との重合性架橋剤、カルボキシル基との反応性架橋剤、又はこれらを併せ持った架橋剤等が挙げられる。
本発明において使用される重合開始剤は、重合形態によって適宜選択され、特に限定されないが、例えば、光分解型重合開始剤、熱分解型重合開始剤、レドックス系重合開始剤等が挙げられる。
本発明に係る吸水性樹脂粉末の製造方法において、その重合方法は、噴霧液滴重合又は逆相懸濁重合により粒子状含水ゲルを得てもよいが、得られる吸水性樹脂粉末の加圧下吸水倍率(AAP)、通液性(SFC)及び吸水速度(FSR)、並びに重合制御の容易性等の観点から、水溶液重合が採用される。当該水溶液重合は、タンク式(サイロ式)の無攪拌重合でもよいが、好ましくはニーダー重合又はベルト重合、より好ましくは連続水溶液重合、更に好ましくは高濃度連続水溶液重合、特に好ましくは高濃度・高温開始連続水溶液重合が採用される。尚、攪拌重合とは、含水ゲル(特に重合率10モル%以上、更には50モル%以上の含水ゲル)を攪拌、特に攪拌及び細分化しながら重合することを意味する。無攪拌重合の前後において、単量体水溶液(重合率が0~10モル%未満)を適宜攪拌してもよい。
本発明における重合工程においては、必要に応じて界面活性剤及び/又は分散剤を用いてもよい。界面活性剤及び/又は分散液を用いることで、重合中の吸水性樹脂中に気泡を安定的に懸濁させることができる。又、界面活性剤及び/又は分散剤の種類又は量を適宜調節することにより、所望の物性を有する吸水性樹脂粉末を得ることができる。界面活性剤は非高分子界面活性剤であり、分散剤は高分子分散剤であることが好ましい。又、界面活性剤及び/又は分散剤は、重合前又は重合時のモノマー水溶液の温度が50℃以上となるよりも前の段階で添加されていることが好ましい。
(a)樹脂固形分
ゲル粉砕前の含水ゲルの樹脂固形分は、物性の観点から、10~80重量%であり、好ましくは30~80重量%、より好ましくは40~80重量%、更に好ましくは45~60重量%であり、特に好ましくは50~60重量%である。上記樹脂固形分が10重量%未満の場合、含水ゲルの軟度が増すため、粒子形状又は粒度分布の制御が困難になるおそれがある。上記樹脂固形分が80重量%を超える場合、含水ゲルの硬度が増すため、粒子形状又は粒度分布の制御が困難になるおそれがある。上記含水ゲルの樹脂固形分は、重合濃度又は重合中の水分蒸発、重合工程への吸水性樹脂微粉の添加(微粉リサイクル工程)、必要により重合後の水添加又は部分乾燥等により適宜制御することができる。
ゲル粉砕前の含水ゲルのCRC(本明細書中にて「ゲルCRC」と称する)は、10~35[g/g]が好ましく、10~32[g/g]がより好ましく、10~30[g/g]が更に好ましく、15~30[g/g]が特に好ましい。上記ゲルCRCが、10[g/g]未満又は35[g/g]を超える場合、ゲル粉砕時の粒子形状又は粒度分布の制御が困難になるおそれがある。上記ゲルCRCは、重合時の架橋剤添加量、その他重合濃度等により適宜制御することができる。尚、高いゲルCRCを有する吸水性樹脂が好ましいことは周知の事実であるが、本発明において上記ゲルCRCが35[g/g]を超える場合、粒子形状又は粒度分布の制御が困難であることが見出された。
ゲル粉砕前の含水ゲルの水可溶分(ゲルExt)は、0.1~10重量%が好ましく、0.5~8重量%がより好ましく、1~5重量%が更に好ましい。上記ゲルExtが10重量%を超える場合、ゲル粉砕によるせん断によって増加する水可溶分の重量平均分子量が過剰となり、所望する通液性が得られないおそれがある。上記ゲルExtは小さい方が好ましいが、上記(c)ゲルCRCとのバランス、又はゲルExtを低減するために必要な製造コスト、或いは生産性の低下等の観点から、下限値は上記範囲である。
ゲル粉砕前の含水ゲルにおける水可溶分の重量平均分子量は、50,000~450,000[Da]が好ましく、100,000~430,000[Da]がより好ましく、150,000~400,000[Da]が更に好ましい。
本工程は、本発明に係るゲル粉砕装置を用いて行う工程であり、上述した重合中又は重合後の含水ゲル状架橋重合体を細分化して、粒子状の含水ゲル状架橋重合体を得る工程である。尚、下記(3-4)粉砕工程・分級工程の「粉砕」と区別して、本工程は「ゲル粉砕」という。
本発明におけるゲル粉砕は、重合後の含水ゲルに対して行われるが、水溶液中に分散している「十分にゲル化」した状態のゲルに対して行うこともできる。
(a)粒度
上記重合工程にて得られた含水ゲル状架橋重合体(含水ゲル)は、上述した本発明のゲル粉砕装置を用いて粉砕され粒子状にされる。尚、ゲル粒子径は分級又は調合等によって制御することができるが、好ましくは本発明に係るゲル粉砕装置によってゲル粒子径が制御される。
本発明において、ゲル粉砕後における粒子状含水ゲルのゲルCRCは、10~35[g/g]が好ましく、10~32[g/g]がより好ましく、15~30[g/g]が更に好ましい。尚、ゲル粉砕後のゲルCRCは、ゲル粉砕前のゲルCRCに対して-1~+3[g/g]とされることが好ましく、+0.1~+2[g/g]とされることがより好ましく、+0.3~+1.5[g/g]とされることが更に好ましい。尚、ゲル粉砕時に架橋剤の使用等によってゲルCRCを減少させてもよいが、上記範囲でゲルCRCを上昇させることが好ましい。
本発明において、ゲル粉砕後における粒子状含水ゲルのゲルExtは、0.1~20重量%が好ましく、0.1~10重量%がより好ましく、0.1~8重量%が更に好ましく、0.1~5重量%が特に好ましい。又、ゲル粉砕後の粒子状含水ゲルのゲルExt増加量(ゲル粉砕前のゲルExtに対する増加量)は、5重量%以下が好ましく、4重量%以下がより好ましく、3重量%以下が更に好ましく、2重量%以下が特に好ましく、1重量%以下が最も好ましい。又、下限値はマイナス(例えば、-3.0重量%、更には-1.0重量%)でもよいが、通常は0重量%以上、好ましくは0.1重量%以上、より好ましくは0.2重量%以上、更に好ましくは0.3重量%以上である。具体的には、好ましくは0~5.0重量%、より好ましくは0.1~3.0重量%等、上述した上限値と下限値の任意の範囲内となるように、ゲルExtを増加するまでゲル粉砕すればよい。尚、ゲル粉砕時に架橋剤の使用等によってゲルExtを減少させてもよいが、上記範囲でゲルExtを上昇させることが好ましい。ここで、ゲルExt増加量の有効数字は小数点以下1桁であるが、例えば、5重量%と5.0重量%は互いに同じであるとして扱う。
本発明において、ゲル粉砕による含水ゲルの水可溶分の重量平均分子量の増加量としては、下限値は10,000[Da]以上が好ましく、20,000[Da]以上がより好ましく、30,000[Da]以上が更に好ましい。又、上限値は、500,000[Da]以下が好ましく、400,000[Da]以下がより好ましく、250,000[Da]以下が更に好ましく、100,000[Da]以下が特に好ましい。例えば本発明において、ゲル粉砕前の含水ゲルに対する、ゲル粉砕後の粒子状含水ゲルの、水可溶分の重量平均分子量の増加量は、10,000~500,000[Da]であり、好ましくは20,000~400,000[Da]であり、より好ましくは30,000~250,000[Da]であり、更に好ましくは30,000~100,000[Da]である。
本発明において、ゲル粉砕後の粒子状含水ゲルの樹脂固形分は、物性の観点から、10~80重量%が好ましく、30~80重量%がより好ましく、50~80重量%、45~85重量%又は45~70重量%が更に好ましく、50~60重量%又は45~60重量%が特に好ましい。ゲル粉砕後の粒子状含水ゲルの樹脂固形分を上記範囲とすることにより、乾燥によるCRCの上昇が制御しやすく、又、乾燥による影響(水可溶分の増加等)が少ないため、好ましい。尚、ゲル粉砕後の樹脂固形分は、ゲル粉砕前の樹脂固形分又は必要により添加する水、更にはゲル粉砕時の加熱による水分蒸発等によって、適宜制御することができる。
上記ゲル粉砕前の含水ゲル又はゲル粉砕後の粒子状含水ゲルの物性を評価するには、製造装置から必要量及び頻度にてサンプリング及び測定する必要がある。この測定値が十分に平均化された数値となるようにする必要があるが、例えば、連続ニーダーやミートチョッパー等による連続式のゲル粉砕で吸水性樹脂粉末の生産量が1~20[t/hr]又は1~10[t/hr]の場合、含水ゲル100kg毎に2点以上、合計で少なくとも10点以上のサンプリング及び測定を行い、粒子状含水ゲルの物性を評価すればよい。
本工程は、上記ゲル粉砕工程にて得られた粒子状含水ゲルを乾燥し、乾燥重合体を得る工程であり、以下、本発明にて好ましく適用される乾燥方法について説明する。
本発明における乾燥工程(好ましくは、上記通気ベルト型乾燥機)での乾燥温度は、100~300℃であり、好ましくは150~250℃であり、より好ましくは160~220℃であり、更に好ましくは170~200℃である。上記乾燥温度を100~300℃とすることで、乾燥時間の短縮と得られる乾燥重合体の着色の低減との両立が可能となる。更に、得られる吸水性樹脂粉末の加圧下吸水倍率が向上する傾向が見られる。尚、乾燥温度が300℃を超えると、高分子鎖が影響を受け、物性が低下するおそれがある。又、乾燥温度が100℃未満では、吸水速度に変化はなく、未乾燥物が生成し、後の粉砕工程時に詰まりが生じる。
本発明における乾燥工程(好ましくは、上記通気ベルト型乾燥機)での乾燥時間は、粒子状含水ゲルの表面積及び乾燥機の種類等に依存し、目的とする含水率となるように適宜設定すればよいが、好ましくは1分間~10時間、より好ましくは5分間~2時間、更に好ましくは10分間~1時間、特に好ましくは15分間~45分間である。
本発明における乾燥工程において、本発明の課題をより解決するために、上記通気乾燥機、特にベルト型乾燥機での熱風の風速は、垂直方向(上下方向)に、0.8~2.5[m/s]であり、1.0~2.0[m/s]が好ましい。上記風速を上記範囲とすることで、得られる乾燥重合体の含水率を所望の範囲に制御することができるだけでなく、吸水速度が向上する。上記風速が0.8[m/s]未満の場合、乾燥時間が遅延し、得られる吸水性樹脂粉末の加圧下吸水倍率が劣るおそれがある。又、上記風速が2.5[m/s]を超える場合、乾燥期間中に粒子状含水ゲルが舞い上がり安定した乾燥が困難というおそれがある。
本発明における乾燥工程において、上記通気ベルト型乾燥機で用いられる熱風は、少なくとも水蒸気を含有し、かつ露点が好ましくは30~100℃、より好ましくは30~80℃である。熱風の露点又は更に好ましくはゲル粒径を上記範囲に制御することで残存モノマーを低減することができ、更に、乾燥重合体の嵩比重の低下を防止することができる。尚、上記露点は、粒子状含水ゲルの含水率が少なくとも10重量%以上、好ましくは20重量%以上の時点での値とする。
上記ゲル粉砕工程にて得られた粒子状含水ゲルは、本乾燥工程にて乾燥され、乾燥重合体とされるが、その乾燥減量(粉末又は粒子1gを180℃で3時間加熱)から求められる樹脂固形分は、好ましくは80重量%を超え、より好ましくは85~99重量%、更に好ましくは90~98重量%、特に好ましくは92~97重量%である。
上記ゲル粉砕工程にて得られた粒子状含水ゲルの、乾燥機に投入される直前の粒子状含水ゲルの表面温度は、40~110℃が好ましく、60~110℃がより好ましく、60~100℃が更に好ましく、70~100℃が特に好ましい。40℃に満たない場合、乾燥時に風船状乾燥物が生じ、粉砕時に微粉が多く発生し、吸水性樹脂の物性の低下を招くおそれがある。乾燥前の粒子状含水ゲルの表面温度が110℃を超える場合、乾燥後の吸水性樹脂の劣化(例えば、水可溶分の増加等)又は着色が生じるおそれがある。
本工程は、上記乾燥工程にて得られた乾燥重合体を、粉砕・分級して、吸水性樹脂粒子を得る工程である。尚、上記(3-2)ゲル粉砕工程とは、粉砕時の樹脂固形分、特に粉砕対象物が乾燥工程を経ている点(好ましくは、上記樹脂固形分まで乾燥)で異なる。又、粉砕工程後に得られる吸水性樹脂粒子を粉砕物と称することもある。
本発明におけるゲル粉砕、更に好ましくは特定の温度及び風速での乾燥によって得られる吸水性樹脂粉末は、特定の内部気泡率とすることができる。又、上記粉砕・分級で得られる吸水性樹脂粒子についても同様に適用される。即ち、表面架橋前の吸水性樹脂粒子は、好ましくは、粒子径が150μm以上、850μm未満である粒子の割合が95重量%以上であり、かつ、粒度分布の対数標準偏差(σζ)が0.25~0.50であって、下記式
(内部気泡率)[%]={(真密度)-(見かけ密度)}/(真密度)×100
で規定される内部気泡率が0~3.7%であることが好ましく、0.6~3.5%であることがより好ましく、1.0~3.3%であることが更に好ましく、1.4~3.1%であることが特に好ましい。
本発明に係るポリアクリル酸(塩)系吸水性樹脂粉末の製造方法は、吸水性能(圧力に対する吸収性、通液性、吸収速度等)の向上のため、好ましくは表面処理工程を更に含む。表面処理工程は、公知の表面架橋剤及び表面架橋方法を用いて行う表面架橋工程を含み、更に必要に応じてその他の添加工程を含む。
本発明にて用いることのできる表面架橋剤としては、種々の有機又は無機架橋剤を例示することができるが、有機表面架橋剤が好ましい。物性面において、好ましくは、表面架橋剤として、多価アルコール化合物、エポキシ化合物、多価アミン化合物又はそのハロエポキシ化合物との縮合物、オキサゾリン化合物、(モノ、ジ、又はポリ)オキサゾリジノン化合物、アルキレンカーボネート化合物であり、特に高温での反応が必要な、多価アルコール化合物、アルキレンカーボネート化合物、オキサゾリジノン化合物からなる脱水反応性架橋剤を使用することができる。脱水反応性架橋剤を使用しない場合、より具体的には、米国特許第6228930号、同第6071976号、同第6254990号等に例示されている化合物を挙げることができる。例えば、モノ,ジ,トリ又はテトラプロピレングリコール、1,3-プロパンジオール、グリセリン、1,4-ブタンジオール、1,3-ブタンジオール、1,5-ペンタンジオール、1,6-ヘキサンジオール、ソルビトール等の多価アルコール化合物;エチレングリコールジグリシジルエーテルやグリシドール等のエポキシ化合物;エチレンカーボネート等のアルキレンカーボネート化合物;オキセタン化合物;2-イミダゾリジノンのような環状尿素化合物等が挙げられる。
表面架橋剤の使用量は、吸水性樹脂粒子100重量部に対して、好ましくは0.001~10重量部、より好ましくは0.01~5重量部程度で適宜決定される。表面架橋剤に合わせて、水が好ましく使用される。使用される水の量は、吸水性樹脂粒子100重量部に対して、好ましくは0.5~20重量部の範囲、より好ましくは0.5~10重量部の範囲である。無機表面架橋剤と有機表面架橋剤とを併用する場合も、吸水性樹脂粒子100重量部に対して、それぞれ、好ましくは0.001~10重量部の範囲、より好ましくは0.01~5重量の範囲で併用される。
表面架橋剤の混合には、縦型又は横型の高速回転攪拌型の混合機が好適に使用される。該混合機の回転数は100~10,000rpmが好ましく、300~2,000rpmがより好ましい。又、装置内における吸水性樹脂の滞留時間は180秒以内が好ましく、0.1~60秒がより好ましく、1~30秒が更に好ましい。
本発明において用いられる表面架橋方法として、上記表面架橋剤を用いる表面架橋に代わって、ラジカル重合開始剤を用いる表面架橋方法(米国特許第4783510号、国際公開第2006/062258号)、又は吸水性樹脂の表面で単量体を重合する表面架橋方法(米国出願公開第2005/048221号、同第2009/0239966号、国際公開第2009/048160号)を用いてもよい。
本発明では、上述した表面架橋工程と同時又は別途に、多価金属塩、カチオン性ポリマー又は無機微粒子の何れか一つ以上を添加する添加工程を更に含む。好ましくは、多価金属塩、又は無機微粒子の何れか一つ以上を添加する添加工程を更に含む。即ち、上記有機表面架橋剤以外に無機表面架橋剤を使用又は併用して通液性・吸水速度等を向上させてもよい。上記無機表面架橋剤は、上記有機表面架橋剤と同時又は別途に使用することができる。使用される無機表面架橋剤としては、2価以上、好ましくは3価若しくは4価値の多価金属の塩(有機塩又は無機塩)又は水酸化物を例示することができる。使用することができる多価金属としては、アルミニウム、ジルコニウム等が挙げられ、乳酸アルミニウム又は硫酸アルミニウムが挙げられる。好ましくは硫酸アルミニウムを含む水溶液である。これらの無機表面架橋は、有機表面架橋剤と同時又は別途に使用される。多価金属による表面架橋は国際公開第2007/121037号、同第2008/09843号、同第2008/09842号、米国特許第7157141号、同第6605673号、同第6620889号、米国特許出願公開第2005/0288182号、同第2005/0070671号、同第2007/0106013号、同第2006/0073969号に示されている。
本発明において好ましくは、表面架橋後の吸水性樹脂粉末の加圧下吸水倍率(AAP)が20[g/g]以上(より好ましくは22[g/g]以上、更に好ましくは24[g/g]以上、最も好ましくは24.5[g/g]以上であり、上記AAPの上限値は、好ましくは35[g/g]以下、より好ましくは30[g/g]以下、更に好ましくは28[g/g]以下)の範囲となるまで、又、表面架橋後の無加圧下吸水倍率(CRC)が10[g/g]以上(より好ましくは20[g/g]以上、更に好ましくは25[g/g]以上、最も好ましくは27[g/g]以上であり、上記CRCの上限値は、好ましくは50[g/g]以下、より好ましくは45[g/g]以下、更に好ましくは42[g/g]以下)の範囲となるまで、反応温度や反応時間等を適宜調整する等して表面架橋される。
上記工程以外に、必要により、蒸発モノマーのリサイクル工程、造粒工程、微粉除去工程、微粉リサイクル工程等を設けてもよく、経時色調の安定性効果又はゲル劣化防止等のために、上記各工程の何れか一部又は全部に、以下の添加剤を必要により使用してもよい。即ち、水溶性又は水不溶性のポリマー、滑剤、キレート剤、消臭剤、抗菌剤、水、界面活性剤、水不溶性微粒子、酸化防止剤、還元剤等を、吸水性樹脂に対して、好ましくは0~30重量%、より好ましくは0.01~10重量%を添加混合することができる。これらの添加剤は、表面処理剤として使用することもできる。
(4-1)AAP(圧力に対する吸収性)
本発明で得られる吸水性樹脂粉末のAAP(加圧下吸水倍率)は、紙オムツでのモレを防止するため、上記重合を達成手段の一例として、4.8kPaの加圧下におけるAAPとして、17[g/g]以上が好ましく、20[g/g]以上がより好ましく、22[g/g]以上が更に好ましく、23[g/g]以上がより更に好ましく、24[g/g]以上が特に更に好ましく、24.5[g/g]以上が最も好ましい。AAPの上限値は、特に限定されないが、他の物性とのバランスから、35[g/g]以下が好ましく、30[g/g]以下がより好ましく、28[g/g]以下が更に好ましい。当該AAPは、粒度制御後の表面架橋によって調整する(向上させる)ことができる。尚、表面架橋工程後に行われる工程によっては、当該AAPの値は変化することがある。
本発明で得られる吸水性樹脂粉末のSFC(食塩水流れ誘導性)は、紙オムツでのモレを防止するため、上記製法、特に本発明のゲル粉砕後、好ましくは上記粒度制御の後、表面架橋によって向上させることができ、上述したAAPの範囲となるまでの表面架橋を達成手段の一例として、加圧下での液の通液特性である0.69%塩化ナトリウム水溶液流れ誘導性(SFC)として、10[×10-7・cm3・s・g-1]以上が好ましく、20[×10-7・cm3・s・g-1]以上がより好ましく、30[×10-7・cm3・s・g-1]以上が更に好ましく、50[×10-7・cm3・s・g-1]以上がより更に好ましく、70[×10-7・cm3・s・g-1]以上が特に好ましく、100[×10-7・cm3・s・g-1]以上が最も好ましい。SFCは周知の測定法であり、例えば、米国特許第5562646号で規定することができる。本発明では通液性の向上に、中でもSFCの向上に、特に上記範囲のSFCに、特に10[×10-7・cm3・s・g-1]以上のSFCに、より顕著に効果を発揮するため、かかる高通液性の吸水性樹脂の製法に好適に適用することができる。
本発明で得られる吸水性樹脂粉末のCRC(無加圧下吸水倍率)は、10[g/g]以上が好ましく、20[g/g]以上がより好ましく、25[g/g]以上が更に好ましく、27[g/g]以上が特に好ましい。CRCの上限値は、特に限定されないが、他の物性のバランスから、50[g/g]以下が好ましく、45[g/g]以下がより好ましく、42[g/g]以下が更に好ましい。当該CRCは、重合時の架橋剤量及びその後の表面架橋(2次架橋)によって適宜制御することができる。
本発明で得られる吸水性樹脂粉末のExt(水可溶分)は、液溶出分の影響で紙オムツでの使用時のべとつき等を防ぐため、35重量%以下が好ましく、25重量%以下がより好ましく、15重量%以下が更に好ましく、10重量%以下が特に好ましい。当該Extは、重合時の架橋剤量及びその後のゲル粉砕での水可溶分量増加によって適宜制御することができる。
本発明で得られる吸水性樹脂粉末のResidual Monomers(残存モノマー)は、安全性の観点から、上記重合を達成手段の一例として、通常、500ppm以下、好ましくは0~400ppm、より好ましくは0~300ppm、特に好ましくは0~200ppmに制御される。当該残存モノマーは、重合時の重合開始剤及びその後の乾燥条件等によって適宜制御することができる。
本発明で得られる吸水性樹脂粉末のFSR(吸水速度)は、紙オムツでのモレを防止するため、上記重合を達成手段の一例として、通常0.2[g/(g・s)]以上であり、0.25[g/(g・s)]以上が好ましく、0.30[g/(g・s)]以上がより好ましく、0.35[g/(g・s)]以上が更に好ましく、0.40[g/(g・s)]以上が特に好ましく、0.45[g/(g・s)]以上が最も好ましい。又、FSRの上限値としては、1.00[g/(g・s)]以下である。FSRの測定法は、国際公開第2009/016055号で規定することができる。当該FSRは、本発明の製造方法及び乾燥後の上記粒度制御で調整することができる。
本発明で得られる吸水性樹脂粉末の熱伝導率は、紙オムツの保温性を向上させるため、125[mW/(m・K)]以下であることが好ましく、120[mW/(m・K)]以下であることがより好ましく、116[mW/(m・K)]以下であることが更に好ましい。又、熱伝導率の下限値は、測定装置にもよるが通常、20[mW/(m・K)]である。
本発明で得られる吸水性樹脂粉末の耐衝撃試験後の150μm未満の粒子の割合は、保温性能、紙オムツ作製時の取り扱い性、通液性能を向上させるため、0~4.5質量%であることが好ましく、0~4.0質量%であることがより好ましく、0~3.5質量%であることが更に好ましく、0~3.0質量%であることが特に好ましく、0~2.5質量%であることが最も好ましい。
本発明で得られる吸水性樹脂粉末の下記式
(内部気泡率)[%]={(真密度)-(見かけ密度)}/(真密度)×100
で規定される内部気泡率は、0~3.7%であることが好ましく、0.6~3.5%であることがより好ましく、1.0~3.3%であることが更に好ましく、1.4~3.1%であることが特に好ましい。内部気泡率を上記範囲とすることで、保温性能と通液性能とを共に向上させ易くなる。
本発明で得られる吸水性樹脂粉末の質量平均粒子径D50は、物性の向上の観点から、250~500μmが好ましく、300~500μmがより好ましく、350~460μmが更に好ましい。
本発明で得られる吸水性樹脂粉末の表面張力は、紙オムツからの液の戻り量を減少させるという観点から、好ましくは60.0[mN/m]以上、より好ましくは65.0[mN/m]以上、更に好ましくは67.0[mN/m]以上、更により好ましくは69.0[mN/m]以上、特に好ましくは70.0[mN/m]以上、最も好ましくは72.0[mN/m]以上である。
本発明で得られる吸水性樹脂粉末は、通液性等の性能を向上するために、前述の多価金属塩、無機微粒子の何れか1つ以上を含むことが好ましい。又、その含有量は好ましくは0.01質量%~1質量%、より好ましくは0.02質量%~0.5質量%である。
本発明に係る製造方法にて得られる吸水性樹脂粉末の用途は特に限定されないが、好ましくは紙オムツ、生理用ナプキン、失禁パット等の吸収性物品に使用される。これまで原料由来の臭気や着色等が問題になっていた高濃度オムツ(紙オムツ1枚当りの吸水性樹脂使用量が多い紙オムツ)、特に上記吸収性物品の吸収体上層部に使用した場合に、優れた性能を発揮する。
以下、実施例に従って本発明を説明するが、本発明は実施例に限定されて解釈されるものではない。又、本発明の特許請求の範囲又は実施例に記載の諸物性は、特に記載のない限り、室温(20~25℃)、湿度50RH%の条件下で、EDANA法及び以下の測定法に従って求めた。更に、実施例及び比較例に提示される電気機器は、特に記載が無い場合には、200V又は100V、60Hzの電源を使用した。尚、便宜上、「リットル」を「L」、「重量%」を「wt%」と記載することがある。
CRC(無加圧下吸水倍率)の測定はERT441.2-02に準じて行った。即ち、吸水性樹脂0.200gを秤量し、不織布製の袋(60×60mm)に均一に入れてヒートシールした後、25±3℃に調温した0.9重量%塩化ナトリウム水溶液1000mL中に浸漬した。30分経過後、袋を引き上げ、遠心分離機(株式会社コクサン社製遠心機、形式;H-122)を用いて、250G、3分間の条件で水切りを行った。その後、袋の重量W1[g]を測定した。同様の操作を、吸水性樹脂を入れずに行い、そのときの袋の重量W2[g]を測定した。次式(3)
CRC[g/g]={(W1-W2)/(吸水性樹脂の重量)}-1
・・・式(3)
に従ってCRC(無加圧下吸水倍率)を算出した。
{msi×(Wn/100)}
・・・式(4)
ここで、
msi;測定前の含水ゲルの重量[g]
mb;自由膨潤して水切り後のBlank(不織布の袋のみ)の重量[g]
mwi;自由膨潤して水切り後の含水ゲルの重量[g]
Wn;含水ゲルの固形分[重量%]
である。
Ext(水可溶分)の測定は、ERT470.2-02に準じて行った。即ち、容量250mLの蓋付きプラスチック容器に、吸水性樹脂1.000gと0.90重量%塩化ナトリウム水溶液200mLとを入れ、長さ3.5cm×直径6mmの円筒型スターラーで400rpm、16時間攪拌を行い、吸水性樹脂中の水可溶分を抽出した。この抽出液を濾紙(ADVANTEC東洋株式会社、品名:JIS P 3801、No.2、厚さ0.26mm、保留粒子径5μm)1枚を用いて濾過し、得られた濾液50.0gを測定液とした。
Ext[重量%]=0.1×(モノマーの平均分子量)×200×100×
([HCl]-[bHCl])/1000/1.000/50.0
・・・式(5)
に従ってExt(水可溶分)を算出した。
{ms×(Wn/100)×1000}
・・・式(6)
ここで、
VHCl.s;溶解したポリマーを含む濾液をpH10からpH2.7にするのに必要なHCl量[mL]
VHCl.b;Blank(0.9重量%塩化ナトリウム水溶液)をpH10からpH2.7にするのに必要なHCl量[mL]
CHCl;HCl溶液の濃度[mol/L]
Mw;アクリル酸(塩)ポリマー中のモノマーユニットの平均分子量[g/mol]
(例えば、中和率73モル%の場合のMwは、88.1[g/mol])
Fdil;溶解したポリマーを含む濾液の希釈度
ms;測定前の含水ゲルの重量[g]
Wn;含水ゲルの固形分[重量%]
である。
水可溶分の重量平均分子量は、上述したExt及びゲルExtの測定操作で溶解したポリマーの重量平均分子量をGPCで測定した値である。以下、GPC測定について説明する。
ガードカラム:SHODEX GF-7B
カラム:TOSOH GMPWXL を2本直列に繋いで使用
検出器:ビスコテック社製TDA302(系内温度は30℃で保持)
溶媒:リン酸2水素ナトリウム2水和物60mM・リン酸水素2ナトリウム12水和物20mM水溶液
流速:0.5mL/min
注入量:100μL
装置の校正は、ポリオキシエチレングリコール(重量平均分子量(Mw)22396、示差屈折率(dn/dc)=0.132、溶媒屈折率1.33)を標準サンプルとして行った。
吸水性樹脂の重量平均粒子径(D50)及び粒度分布の対数標準偏差(σζ)の測定は、欧州特許第0349240号に記載された測定方法に準じて行った。一方、含水ゲルの重量平均粒子径(D50)及び粒度分布の対数標準偏差(σζ)は、以下の方法で測定した。
R(α)[mm]=(20/w)1/3×r ・・・式(8)
ここで、
X;分級、水切り後に各篩上に残留した含水ゲルの重量%[%]
w;分級、水切り後に各篩上に残留した含水ゲルのそれぞれの重量[g]
W;分級、水切り後に各篩上に残留した含水ゲルの総重量[g]
R(α);固形分α重量%の含水ゲルに換算したときの篩の目開き[mm]
r;20重量%塩化ナトリウム水溶液中で膨潤した含水ゲルが分級された篩の目開き[mm]
である。
X1は、R=84.1%のときの粒子径であり、X2は、R=15.9%のときの粒子径である。
吸水性樹脂の水分を除去した後、樹脂内部に存在する気泡(内部気泡)を考慮した見かけ密度を乾式密度計で測定(所定重量の吸水性樹脂についてその体積を乾式測定)した。
吸水性樹脂内部に存在する内部気泡(独立気泡)の径は、通常1~300μmであるが、粉砕時には、独立気泡に近い部分から優先的に粉砕される。そこで、粒子径が45μm未満となるまで吸水性樹脂を粉砕すると、得られた吸水性樹脂には独立気泡がほとんど含まれない。従って、45μm未満まで粉砕された吸水性樹脂の乾式密度を本発明では真密度として評価した。
上記[見かけ密度]に記載した方法で測定した見かけ密度(これをρ1[g/cm3]とする)、及び上記[真密度]に記載した方法で測定した真密度(これをρ2[g/cm3]とする)を用いて、吸水性樹脂の内部気泡率を下記式(10)
内部気泡率[%]=(ρ2-ρ1)/ρ2×100 ・・・式(10)
に従って算出した。
本発明における吸水速度「FSR」とは、Free Swell Rateの略称であり、吸水速度(自由膨潤速度)を意味する。具体的に「FSR」とは、吸水性樹脂1gが0.9重量%塩化ナトリウム水溶液20gを吸水するときの速度(単位;[g/(g・s)])をいう。
FSR[g/(g・s)]=20.0/(ts[秒]×1.00)
・・・式(11)
に従って求めた。
米国特許第6562879号及びその対応特許である日本国公開特許公報「特開2000-302876号」(12頁の段落[0058])に記載の「(機械的ダメージ試験)」方法にて、吸水性樹脂粉末にダメージを与えた。具体的には、ガラス製容器(日本山村硝子株式会社製、マヨネーズ瓶、商品名:A-29)に吸水性樹脂粉末30gとガラスビーズ(玉径約6mmの精密分留充填用ソーダ石灰ガラスビーズ)10gとを入れた。これを、分散機(株式会社東洋精機製作所製、No.488試験用分散機)に備えられたクランプ間に挟んで固定し、100V/60Hzで振動回転数750cpmの振動を30分間与えた。これにより、上記分散機に固定された容器は、分散機における上記クランプの取り付け面に対して左右に各々12.5°(合計25°)傾斜運動すると同時に、前後に各々8mm(合計16mm)振動することにより、容器内部の吸水性樹脂粉末に衝撃を与えた。
耐衝撃試験後の150μm未満の粒子の割合[質量%]={(目開き150μmを通過した粒子の質量[g])/(吸水性樹脂粉末の質量[g])}×100
に従って求めた。
吸水性樹脂の水分を除去した後、吸水性樹脂粉末の熱伝導率を熱線法によって測定した。即ち、吸水性樹脂粉末150gをステンレスバット(縦29cm×横29cm×高さ5cm)に散布した後、温度を80℃に調整した減圧乾燥機(アズワン株式会社製;ETTAS AVO-310NB)に静置し、小型油回転真空ポンプ(アルバック機工株式会社製;GLD-136C)で乾燥機内の圧力が100Pa以下となるまで減圧し、減圧乾燥を行った。当該作業は、吸水性樹脂粉末の固形分が97±0.5%になるまで続けた。
・・・式(12)
ここで、
λ:熱伝導率[mW/(m・K)]
K,H:プローブ定数
R:プローブヒーター単位長さあたりの熱抵抗[Ω/m]
I:加熱電流[A]
t1,t2:電流を印加してからの時間[s](t1=30、t2=60)
T1,T2:t1,t2における温度[℃]
である。
本発明に係る吸水性樹脂粉末の見かけ損失熱量の測定は以下のように行った。
+(T1-23.5)×0.00283×5×900
・・・式(13)
ここで、K[W/(m・K)]は吸水性樹脂粉末の熱伝導率、T1[℃]は吸水性樹脂粉末が24℃に達してから15分後の温度である。
本発明に係る吸収体の吸収体損失熱量の測定は以下のように行った。
Qd[J]=30×1×(T2-30) ・・・式(14)
より求めた。
国際公開WO2011/126079号公報の製造例1に準じて含水ゲルの製造を行った。
製造例1の、ポリエチレングリコールジアクリレート(平均n数;9)の使用量を1.05重量部に変更して、同様の操作を行い帯状の含水ゲル(2)及び切断含水ゲル(2)を得た。該帯状の含水ゲル(2)は、CRC28.6[g/g]、樹脂固形分53.0重量%、水可溶分4.2重量%、水可溶分の重量平均分子量26.2×104[Da]であった。
製造例1の、ポリエチレングリコールジアクリレート(平均n数;9)の使用量を0.84重量部に変更して、同様の操作を行い帯状の含水ゲル(3)及び切断含水ゲル(3)を得た。該帯状の含水ゲル(3)は、CRC30.2[g/g]、樹脂固形分53.0重量%、水可溶分4.9重量%、水可溶分の重量平均分子量35.4×104[Da]であった。
製造例1の、ポリエチレングリコールジアクリレート(平均n数;9)の使用量を0.31重量部に変更して、同様の操作を行い帯状の含水ゲル(4)及び切断含水ゲル(4)を得た。該帯状の含水ゲル(4)は、CRC41.3[g/g]、樹脂固形分52.8重量%、水可溶分8.0重量%、水可溶分の重量平均分子量73.6×104[Da]であった。
製造例1から以下の点について追加・変更を行い、その他は製造例1と同様の操作を行った。
製造例1の、ポリエチレングリコールジアクリレート(平均n数;9)の使用量を0.63質量部に変更して、同様の操作を行い帯状の含水ゲル(6)及び切断含水ゲル(6)を得た。
製造例1の、ポリエチレングリコールジアクリレート(平均n数;9)の使用量を0.49質量部に変更して、同様の操作を行い帯状の含水ゲル(7)及び切断含水ゲル(7)を得た。
製造例1にて得られた切断含水ゲル(1)を本発明に係るゲル粉砕装置に供給し、ゲル粉砕した。上記ゲル粉砕装置のスクリュー及びバレルとして、表1に記載のスクリューNo.S53-422、及び、表2に記載のバレルNo.B58-833を用いた。又、上記ゲル粉砕装置に、直径が68mm、ダイス孔径が7.5mm、ダイス厚さが8mmの多孔板を搭載した。表3に上記ゲル粉砕装置のスクリューの断面積比B/A、スクリューフライト幅内径比F/Nを示す。
次に、上記比較粒子状含水ゲル(1)を熱風乾燥機の乾燥網上に散布した。このときの比較粒子状含水ゲル(1)の温度は80℃であった。散布した後、190℃で30分間乾燥を行い、比較乾燥重合体(1)を得た。上記熱風乾燥機の熱風の平均風速は乾燥網の平面に対して垂直方向に1.0[m/s]であった。尚、熱風の風速は、日本カノマックス株式会社製の定温度熱式風速計アネモマスター6162を用いて測定した。
製造例2にて得られた切断含水ゲル(2)を本発明に係るゲル粉砕装置に供給し、ゲル粉砕した。上記ゲル粉砕装置のスクリュー及びバレルとして、表1に記載のスクリューNo.S86-433、及び、表2に記載のバレルNo.B88-478を用いた。又、上記ゲル粉砕装置に、直径が100mm、ダイス孔径が9.5mm、ダイス厚さが10mmの多孔板を搭載した。表3に上記ゲル粉砕装置のスクリューの断面積比B/A、スクリューフライト幅内径比F/Nを示す。
製造例2にて得られた切断含水ゲル(2)を本発明に係るゲル粉砕装置に供給し、ゲル粉砕した。上記ゲル粉砕装置のスクリュー及びバレルとして、表1に記載のスクリューNo.S86-435、及び、表2に記載のバレルNo.B88-478を用いた。そして、比較例2と同様の操作を行い、粒子状含水ゲル(1)、吸水性樹脂粒子(1)及び吸水性樹脂粉末(1)を得た。このときのゲル粉砕エネルギー(2)(GGE(2))は、7.7[J/g]であった。上記ゲル粉砕装置のスクリューの断面積比B/A、スクリューフライト幅内径比F/N、及び吸水性樹脂粉末(1)の諸物性を表3に示す。又、吸水性樹脂粒子(1)の諸物性及び吸水性樹脂粉末(1)の他の諸物性を表6に示す。
製造例2にて得られた切断含水ゲル(2)を本発明に係るゲル粉砕装置に供給し、ゲル粉砕した。上記ゲル粉砕装置のスクリュー及びバレルとして、表1に記載のスクリューNo.S86-4310、及び、表2に記載のバレルNo.B88-478を用いた。そして、比較例2と同様の操作を行い、粒子状含水ゲル(2)、吸水性樹脂粒子(2)及び吸水性樹脂粉末(2)を得た。このときのゲル粉砕エネルギー(2)(GGE(2))は、7.7[J/g]であった。上記ゲル粉砕装置のスクリューの断面積比B/A、スクリューフライト幅内径比F/N、及び吸水性樹脂粉末(2)の諸物性を表3に示す。又、吸水性樹脂粒子(2)の諸物性及び吸水性樹脂粉末(2)の他の諸物性を表6に示す。
製造例2にて得られた切断含水ゲル(2)を本発明に係るゲル粉砕装置に供給し、ゲル粉砕した。上記ゲル粉砕装置のスクリュー及びバレルとして、表1に記載のスクリューNo.S86-443、及び、表2に記載のバレルNo.B88-478を用いた。そして、比較例2と同様の操作を行い、粒子状含水ゲル(3)、吸水性樹脂粒子(3)及び吸水性樹脂粉末(3)を得た。このときのゲル粉砕エネルギー(2)(GGE(2))は、8.9[J/g]であった。上記ゲル粉砕装置のスクリューの断面積比B/A、スクリューフライト幅内径比F/N、及び吸水性樹脂粉末(3)の諸物性を表3に示す。又、吸水性樹脂粒子(3)の諸物性及び吸水性樹脂粉末(3)の他の諸物性を表6に示す。
製造例2にて得られた切断含水ゲル(2)を本発明に係るゲル粉砕装置に供給し、ゲル粉砕した。上記ゲル粉砕装置のスクリュー及びバレルとして、表1に記載のスクリューNo.S86-445、及び、表2に記載のバレルNo.B88-478を用いた。そして、比較例2と同様の操作を行い、粒子状含水ゲル(4)、吸水性樹脂粒子(4)及び吸水性樹脂粉末(4)を得た。このときのゲル粉砕エネルギー(2)(GGE(2))は、8.8[J/g]であった。上記ゲル粉砕装置のスクリューの断面積比B/A、スクリューフライト幅内径比F/N、及び吸水性樹脂粉末(4)の諸物性を表3に示す。又、吸水性樹脂粒子(4)の諸物性及び吸水性樹脂粉末(4)の他の諸物性を表6に示す。
製造例2にて得られた切断含水ゲル(2)を本発明に係るゲル粉砕装置に供給し、ゲル粉砕した。上記ゲル粉砕装置のスクリュー及びバレルとして、表1に記載のスクリューNo.S86-4410、及び、表2に記載のバレルNo.B88-478を用いた。そして、比較例2と同様の操作を行い、粒子状含水ゲル(5)、吸水性樹脂粒子(5)及び吸水性樹脂粉末(5)を得た。このときのゲル粉砕エネルギー(2)(GGE(2))は、8.7[J/g]であった。上記ゲル粉砕装置のスクリューの断面積比B/A、スクリューフライト幅内径比F/N、及び吸水性樹脂粉末(5)の諸物性を表3に示す。又、吸水性樹脂粒子(5)の諸物性及び吸水性樹脂粉末(5)の他の諸物性を表6に示す。
製造例2にて得られた切断含水ゲル(2)を本発明に係るゲル粉砕装置に供給し、ゲル粉砕した。上記ゲル粉砕装置のスクリュー及びバレルとして、表1に記載のスクリューNo.S86-463、及び、表2に記載のバレルNo.B88-478を用いた。そして、比較例2と同様の操作を行い、粒子状含水ゲル(6)、吸水性樹脂粒子(6)及び吸水性樹脂粉末(6)を得た。このときのゲル粉砕エネルギー(2)(GGE(2))は、13.5[J/g]であった。上記ゲル粉砕装置のスクリューの断面積比B/A、スクリューフライト幅内径比F/N、及び吸水性樹脂粉末(6)の諸物性を表3に示す。又、吸水性樹脂粒子(6)の諸物性及び吸水性樹脂粉末(6)の他の諸物性を表6に示す。
製造例2にて得られた切断含水ゲル(2)を本発明に係るゲル粉砕装置に供給し、ゲル粉砕した。上記ゲル粉砕装置のスクリュー及びバレルとして、表1に記載のスクリューNo.S86-465、及び、表2に記載のバレルNo.B88-478を用いた。そして、比較例2と同様の操作を行い、粒子状含水ゲル(7)、吸水性樹脂粒子(7)及び吸水性樹脂粉末(7)を得た。このときのゲル粉砕エネルギー(2)(GGE(2))は、13.4[J/g]であった。上記ゲル粉砕装置のスクリューの断面積比B/A、スクリューフライト幅内径比F/N、及び吸水性樹脂粉末(7)の諸物性を表3に示す。又、吸水性樹脂粒子(7)の諸物性及び吸水性樹脂粉末(7)の他の諸物性を表6に示す。
製造例2にて得られた切断含水ゲル(2)を本発明に係るゲル粉砕装置に供給し、ゲル粉砕した。上記ゲル粉砕装置のスクリュー及びバレルとして、表1に記載のスクリューNo.S86-4610、及び、表2に記載のバレルNo.B88-478を用いた。そして、比較例2と同様の操作を行い、粒子状含水ゲル(8)、吸水性樹脂粒子(8)及び吸水性樹脂粉末(8)を得た。このときのゲル粉砕エネルギー(2)(GGE(2))は、13.3[J/g]であった。上記ゲル粉砕装置のスクリューの断面積比B/A、スクリューフライト幅内径比F/N、及び吸水性樹脂粉末(8)の諸物性を表3に示す。又、吸水性樹脂粒子(8)の諸物性及び吸水性樹脂粉末(8)の他の諸物性を表6に示す。
製造例2にて得られた切断含水ゲル(2)を本発明に係るゲル粉砕装置に供給し、ゲル粉砕した。上記ゲル粉砕装置のスクリュー及びバレルとして、表1に記載のスクリューNo.S130-4710、及び、表2に記載のバレルNo.B136-6810を用いた。又、上記ゲル粉砕装置に、直径が160mm、ダイス孔径が16mm、ダイス厚さが14mmの多孔板を搭載した。表3に上記ゲル粉砕装置のスクリューの断面積比B/A、スクリューフライト幅内径比F/Nを示す。
製造例2にて得られた切断含水ゲル(2)を本発明に係るゲル粉砕装置に供給し、ゲル粉砕した。上記ゲル粉砕装置のスクリュー及びバレルとして、表1に記載のスクリューNo.S175-51017、及び、表2に記載のバレルNo.B181-71520を用いた。又、上記ゲル粉砕装置に、直径が220mm、ダイス孔径が16mm、ダイス厚さが25mmの多孔板を搭載した。表3に上記ゲル粉砕装置のスクリューの断面積比B/A、スクリューフライト幅内径比F/Nを示す。
製造例3にて得られた切断含水ゲル(3)を本発明に係るゲル粉砕装置に供給し、ゲル粉砕した。上記ゲル粉砕装置のスクリュー及びバレルとして、表1に記載のスクリューNo.S86-433、及び、表2に記載のバレルNo.B88-478を用いた。そして、比較例2と同様の操作を行い、比較粒子状含水ゲル(3)、比較吸水性樹脂粒子(3)及び比較吸水性樹脂粉末(3)を得た。このときのゲル粉砕エネルギー(2)(GGE(2))は、8.1[J/g]であった。上記ゲル粉砕装置のスクリューの断面積比B/A、スクリューフライト幅内径比F/N、及び比較吸水性樹脂粉末(3)の諸物性を表4に示す。又、比較吸水性樹脂粒子(3)の諸物性及び比較吸水性樹脂粉末(3)の他の諸物性を表6に示す。更に、比較吸水性樹脂粉末(3)の熱伝導率測定、見かけ損失熱量測定、耐衝撃試験、その他吸収性能測定を行った結果を表7に示す。
製造例3にて得られた切断含水ゲル(3)を本発明に係るゲル粉砕装置に供給し、ゲル粉砕した。上記ゲル粉砕装置のスクリュー及びバレルとして、表1に記載のスクリューNo.S86-445、及び、表2に記載のバレルNo.B88-478を用いた。そして、比較例2と同様の操作を行い、粒子状含水ゲル(11)、吸水性樹脂粒子(11)及び吸水性樹脂粉末(11)を得た。このときのゲル粉砕エネルギー(2)(GGE(2))は、9.4[J/g]であった。上記ゲル粉砕装置のスクリューの断面積比B/A、スクリューフライト幅内径比F/N、及び吸水性樹脂粉末(11)の諸物性を表4に示す。又、吸水性樹脂粒子(11)の諸物性及び吸水性樹脂粉末(11)の他の諸物性を表6に示す。
製造例4にて得られた切断含水ゲル(4)を本発明に係るゲル粉砕装置に供給し、ゲル粉砕した。上記ゲル粉砕装置のスクリュー及びバレルとして、表1に記載のスクリューNo.S86-433、及び、表2に記載のバレルNo.B88-478を用いた。そして、比較例2と同様の操作を行い、比較粒子状含水ゲル(4)、比較吸水性樹脂粒子(4)及び比較吸水性樹脂粉末(4)を得た。このときのゲル粉砕エネルギー(2)(GGE(2))は、10.1[J/g]であった。上記ゲル粉砕装置のスクリューの断面積比B/A、スクリューフライト幅内径比F/N、及び比較吸水性樹脂粉末(4)の諸物性を表5に示す。又、比較吸水性樹脂粒子(4)の諸物性及び比較吸水性樹脂粉末(4)の他の諸物性を表6に示す。更に、比較吸水性樹脂粉末(4)の熱伝導率測定、見かけ損失熱量測定、耐衝撃試験、その他吸収性能測定を行った結果を表7に示す。
2013年5月に日本国で購入した紙オムツ(プロクター・アンド・ギャンブル・ジャパン株式会社製:商品名「Pampers さらさらケアパンツ」)から取り出した吸水性樹脂粉末(比較吸水性樹脂粉末(5)とする)、2010年10月にタイ国で購入した紙オムツ(SCA社製:商品名「Drypers WeeWeeDRY」)から取り出した吸水性樹脂粉末(比較吸水性樹脂粉末(6)とする)、2012年7月にタイ国で購入した紙オムツ(大王製紙株式会社製:商品名「GOO.N Pants(Competitor’s)」)から取り出した吸水性樹脂粉末(比較吸水性樹脂粉末(7)とする)、及び、2012年5月に中国で購入した紙オムツ(HENGAN社製:商品名「Anerle 超能吸」)から取り出した吸水性樹脂粉末(比較吸水性樹脂粉末(8)とする)に関して、熱伝導率、見かけ損失熱量、CRC、AAP、SFC、内部気泡率、耐衝撃試験後の150μm未満の粒子の割合を測定した。その結果を表7に示す。
製造例4にて得られた切断含水ゲル(4)を本発明に係るゲル粉砕装置に供給し、ゲル粉砕した。上記ゲル粉砕装置のスクリュー及びバレルとして、表1に記載のスクリューNo.S86-445、及び、表2に記載のバレルNo.B88-478を用いた。そして、比較例2と同様の操作を行い、粒子状含水ゲル(12)、吸水性樹脂粒子(12)及び吸水性樹脂粉末(12)を得た。このときのゲル粉砕エネルギー(2)(GGE(2))は、11.4[J/g]であった。上記ゲル粉砕装置のスクリューの断面積比B/A、スクリューフライト幅内径比F/N、及び吸水性樹脂粉末(12)の諸物性を表5に示す。又、吸水性樹脂粒子(12)の諸物性及び吸水性樹脂粉末(12)の他の諸物性を表6に示す。
製造例5にて得られた切断含水ゲル(5)を本発明に係るゲル粉砕装置に供給し、ゲル粉砕した。上記ゲル粉砕装置のスクリュー及びバレルとして、表1に記載のスクリューNo.S86-4410、及び、表2に記載のバレルNo.B88-478を用いた。そして、比較例2と同様の操作を行い、粒子状含水ゲル(13)、吸水性樹脂粒子(13)及び吸水性樹脂粉末(13)を得た。このときのゲル粉砕エネルギー(2)(GGE(2))は、9.8[J/g]であった。上記ゲル粉砕装置のスクリューの断面積比B/A、スクリューフライト幅内径比F/N、及び吸水性樹脂粉末(13)の諸物性を表3に示す。又、吸水性樹脂粒子(13)の諸物性及び吸水性樹脂粉末(13)の他の諸物性を表6に示す。
実施例1と同じ操作を、ゲルの投入量(処理量)を10.64[kg/min]から17.2[kg/min](430gのゲルを1.5秒おきに投入する)に変更して行い、粒子状含水ゲル(14)、吸水性樹脂粒子(14)及び吸水性樹脂粉末(14)を得た。このときのゲル粉砕エネルギー(2)(GGE(2))は4.5[J/g]、処理量内径比T/N3は1.51[g/hr/mm3]であった。上記ゲル粉砕装置のスクリューの断面積比B/A、スクリューフライト幅内径比F/N、及び吸水性樹脂粉末(14)の諸物性を表3に示す。又、吸水性樹脂粒子(14)の諸物性及び吸水性樹脂粉末(14)の他の諸物性を表6に示す。
0.034<F/N≦0.20を満たしているスクリューを有する本発明に係るゲル粉砕装置を用いた実施例1,2にて製造された吸水性樹脂粉末(1),(2)は、比較例1,2にて製造された比較吸水性樹脂粉末(1),(2)と比較すると、加圧下吸水倍率(AAP)、通液性(SFC)の物性が向上していることが分かる。
製造例6で得られた切断含水ゲル(6)を本願のゲル粉砕装置に供給し、ゲル粉砕した。上記ゲル粉砕装置のスクリュー及びバレルとして、表1に記載のスクリューNo.S86-445、及び、表2に記載のバレルNo.B88-478を用いた。また、ゲル粉砕装置に搭載する多孔板として、直径が100mm、ダイス孔径が9.5mm、ダイス厚さが10mmのものを使用した。そして、比較例2と同様の操作を行い、得られた粒子状含水ゲル(15)を、熱風乾燥機の乾燥網上に散布した。このときの粒子状含水ゲル(15)の温度は80℃であった。散布した後、190℃で30分間乾燥を行い、乾燥重合体(15)を得た。上記熱風乾燥機の熱風の平均風速は、乾燥網の平面に対して垂直方向に1.0[m/s]であった。尚、熱風の風速は、日本カノマックス株式会社製の定温度熱式風速計アネモマスター6162を用いて測定した。
実施例15と同様の操作を、切断含水ゲル(6)を製造例7で得られた切断含水ゲル(7)に変更して行い、吸水性樹脂粉末(16)を得た。吸水性樹脂粉末(16)の粒度分布測定を行ったところ、質量平均粒子径(D50)は376μm、粒度分布の対数標準偏差(σζ)は0.34であり、500μm非通過粒子(目開き500μmの篩を通過しない粒子の割合)は21.6質量%であった。又、吸水性樹脂粉末(16)の表面張力は72.0[mN/m]であった。熱伝導率、見かけ損失熱量、耐衝撃試験、その他吸収性能に関する物性を表7に示す。
実施例15と同様の操作を、切断含水ゲル(6)を製造例4で得られた切断含水ゲル(4)に変更して行い、吸水性樹脂粉末(17)を得た。吸水性樹脂粉末(17)の粒度分布測定を行ったところ、質量平均粒子径(D50)は333μm、粒度分布の対数標準偏差(σζ)は0.33であり、500μm非通過粒子(目開き500μmの篩を通過しない粒子の割合)は19.9質量%であった。又、吸水性樹脂粉末(17)の表面張力は73[mN/m]であった。熱伝導率、見かけ損失熱量、耐衝撃試験、その他吸収性能に関する物性を表7に示す。
実施例17と同様の操作を、ゲル粉砕時に使用するダイスの孔径を7.5mmに変更して行い、吸水性樹脂粉末(18)を得た。吸水性樹脂粉末(18)の粒度分布測定を行ったところ、質量平均粒子径(D50)は331μm、粒度分布の対数標準偏差(σζ)は0.31であり、500μm非通過粒子(目開き500μmの篩を通過しない粒子の割合)は24.3質量%であった。又、吸水性樹脂粉末(18)の表面張力は72[mN/m]であった。熱伝導率、見かけ損失熱量、耐衝撃試験、その他吸収性能に関する物性を表7に示す。
実施例15で得られた吸水性樹脂粉体(15)100質量部に対して、1,4-ブタンジオール0.3質量部、プロピレングリコール0.6質量部及び脱イオン水3.0質量部からなる(共有結合性)表面架橋剤溶液を均一に混合し、208℃で30分間程度、得られる吸水性樹脂表面架橋粒子(19)のCRCが約34[g/g]となるように加熱処理した。その後、目開き710μmのJIS標準篩を通過するまで解砕(整粒工程)し、表面が架橋された吸水性樹脂表面架橋粒子(19)を得た。得られた吸水性樹表面架橋粒子(19)100質量部に、水不溶性無機微粒子(アエロジル200;日本アエロジル株式会社製)0.5質量部を乾式撹拌混合することで、表面が水不溶性無機微粒子で被覆された吸水性樹脂粉末(19)を得た。尚、吸水性樹脂粉末(19)の表面張力、質量平均粒子径(D50)、粒度分布の対数標準偏差(σζ)、500μm非通過粒子(目開き500μmの篩を通過しない粒子の割合)は、実施例15の吸水性樹脂粉末(15)の値とほぼ同程度であった。熱伝導率、見かけ損失熱量、耐衝撃試験、その他吸収性能に関する物性を表7に示す。
実施例15で得られた吸水性樹脂粉体(15)100質量部に対して、エチレングリコールジグリシジルエーテル0.015質量部、プロピレングリコール1.0質量部及び水3.0質量部からなる表面処理剤を均一に混合し、100℃で45分間、加熱処理を行った。その後、目開きが710μmのJIS標準篩で整粒することで、表面が架橋された吸水性樹脂表面架橋粒子(20)を得た。得られた吸水性樹脂表面架橋粒子(20)100質量部にカオリン(製品名Neogen2000、Dry Brabch Kaolin Company製)0.3質量部を混合した。即ち、吸水性樹脂表面架橋粒子(20)30gを容量225mlのマヨネーズ瓶にカオリンと共に入れ、ペイントシェーカー(株式会社東洋精機製作所製)の振動(室温下で3分間)によって混合し、吸水性樹脂粉末(20)を得た。尚、吸水性樹脂粉末(20)の表面張力、質量平均粒子径(D50)、粒度分布の対数標準偏差(σζ)、500μm非通過粒子(目開き500μmの篩を通過しない粒子の割合)は、実施例15の吸水性樹脂粉末(15)の値とほぼ同程度であった。熱伝導率、見かけ損失熱量、耐衝撃試験、その他吸収性能に関する物性を表7に示す。
実施例18で得られた吸水性樹脂粉末(18)30gにパルプ1.5gを均一に混合し、ミニ吸収体を得た。このミニ吸収体に関して、図6に示す装置で吸収体損失熱量を測定した。その結果を表8に示す。但し、トップシート及びバックシートは、ユニチャーム株式会社製、商品名マミーポコテープタイプ、Lサイズ(2014年2月に日本にて購入)から取り出したものを使用した。トップシートは最も着用者側に配置された不織布及び紙からなるシートであり、バックシートは吸収体を挟んでトップシートと反対側にある水不透過性材料である。
比較例1で得られた比較吸水性樹脂粉末(1)30gを用いて実施例21と同様の操作を行い、ミニ吸収体を得た。このミニ吸収体に関して吸収体損失熱量を測定した。その結果を表8に示す。
表7に示すように、本発明に係る吸水性樹脂粉末は、優れた加圧下吸収倍率(AAP)、吸水性能(CRC)、及び通液性(SFC)に加えて、耐衝撃試験後の150μm未満の粒子が少なく、適切な内部気泡率を有しており、熱伝導率が小さく、そのため見かけ損失熱量が小さいことが分かる。このような吸水性樹脂粉末は紙オムツ製造後であっても、高い保温性を有し、表8に示すように吸収体損失熱量が小さい。
12 多孔板
13 バレル
14 供給口
15 ホッパー
16 押出口
17 回転刃
18 リング
19 逆戻り防止部材
20 台
21 モーター及び減速機
22 回転軸
23 フライト部
100 ゲル粉砕装置
200 円筒状アクリル樹脂製セル
201 ステンレス製金網
202 断熱材
203 断熱材
204 塩化ビニル樹脂製ピストン
205 熱電対
206 ホットプレート
207 吸水性樹脂粉末
208 トップシート
209 バックシート
210 錘
211 吸収体
Claims (22)
- スクリュー、供給口、押出口、多孔板、及びバレルを備えた、吸水性樹脂を製造するために使用するゲル粉砕装置であって、
上記スクリューが、回転の中心となる回転軸及び上記回転軸に螺旋状に設けられたフライトを備えており、
上記スクリューを吸水性樹脂のゲルの押出方向に対して垂直に切断したときに得られる上記回転軸の断面積をB、上記フライトの回転部の断面積をA、上記バレルの内部の逆戻り防止部材と上記スクリューとが接触しない最大の内径をN、上記フライトの延伸方向に対して垂直方向の幅をFとしたとき、当該スクリューが、下記(1)又は(2)の何れかを満たしていることを特徴とする、ゲル粉砕装置:
(1)0.215≦B/A≦0.630
(2)0.034<F/N≦0.20。 - 上記フライトと上記バレルとの隙間をσとしたとき、上記スクリューが、0.001≦σ/N<0.043を満たすことを特徴とする、請求項1に記載のゲル粉砕装置。
- 上記スクリューのピッチ長をPとしたとき、上記押出口から上記供給口に向かって1巻目から2巻目までの間の何れかのP/Nが0.15~0.68であることを特徴とする、請求項1又は2に記載のゲル粉砕装置。
- 上記スクリューの材質が上記多孔板の材質と異なることを特徴とする、請求項1~3の何れか一項に記載のゲル粉砕装置。
- 上記スクリューの材質がオーステナイト系ステンレスであることを特徴とする、請求項1~4の何れか一項に記載のゲル粉砕装置。
- ゲル粉砕工程において40℃~120℃で使用することを特徴とする、請求項1~5の何れか一項に記載のゲル粉砕装置。
- 上記吸水性樹脂がポリアクリル酸(塩)系吸水性樹脂であることを特徴とする、請求項1~6の何れか一項に記載のゲル粉砕装置。
- 上記スクリューに回転刃が搭載されていることを特徴とする、請求項1~7の何れか一項に記載のゲル粉砕装置。
- アクリル酸(塩)系単量体水溶液の重合工程と、重合中又は重合後の含水ゲル状架橋重合体のゲル粉砕工程と、ゲル粉砕後の乾燥工程とを含む、ポリアクリル酸(塩)系吸水性樹脂粉末の製造方法であって、
請求項1~8の何れか一項に記載のゲル粉砕装置を用いて、上記ゲル粉砕工程において、樹脂固形分が10~80重量%の含水ゲル状架橋重合体を粉砕する吸水性樹脂粉末の製造方法。 - 上記ゲル粉砕装置の1時間当たりの含水ゲルの処理量をT[g/hr]、上記ゲル粉砕装置の単位時間当たりの処理量を処理量内径比T/N3[g/hr/mm3]としたとき、T/N3が、0.05~2.0であることを特徴とする、請求項9に記載の吸水性樹脂粉末の製造方法。
- 上記ゲル粉砕工程において粉砕した含水ゲルを通気ベルト型乾燥機で、乾燥温度が150~250℃、かつ、熱風の風速が垂直方向(上下方向)に0.8~2.5[m/s]の条件で乾燥を行う、請求項9又は10に記載の吸水性樹脂粉末の製造方法。
- 上記ゲル粉砕工程が行われる際のゲル粉砕装置のバレルの温度が40~120℃である、請求項9~11の何れか一項に記載の吸水性樹脂粉末の製造方法。
- ポリアクリル酸(塩)系吸水性樹脂を主成分とする吸水性樹脂粉末であって、下記(A)~(C)
(A)耐衝撃試験前の150μm未満の粒子割合が0質量%~4.5質量%であり、耐衝撃試験により増加する150μm未満の粒子割合が0質量%~4.5質量%
(B)加圧下吸収倍率(AAP)が17以上
(C)熱伝導率が125[mW/(m・K)]以下
を満たす吸水性樹脂粉末。 - 上記吸水性樹脂粉末の食塩水流れ誘導性(SFC)が10以上であることを特徴とする請求項13に記載の吸水性樹脂粉末。
- 上記吸水性樹脂粉末の、下記式
(内部気泡率)[%]={(真密度)-(見かけ密度)}/(真密度)×100
で規定される内部気泡率が0~3.7%であることを特徴とする請求項13又は14に記載の吸水性樹脂粉末。 - 上記吸水性樹脂粉末が多価金属塩、無機微粒子の何れか1つ以上を含むことを特徴とする請求項13~15の何れか一項に記載の吸水性樹脂粉末。
- 上記吸水性樹脂粉末の質量平均粒子径D50が350~460μmであり、又、粒度分布の対数標準偏差が0.25~0.45であることを特徴とする請求項13~16の何れか一項に記載の吸水性樹脂粉末。
- 上記吸水性樹脂粉末に含まれる目開き710μmを通過し、かつ目開き500μmのふるいを通過しない粒子の割合が36質量%以下であることを特徴とする請求項13~17の何れか一項に記載の吸水性樹脂粉末。
- 上記吸水性樹脂粉末の表面張力が69.0[mN/m]以上であることを特徴とする請求項13~18の何れか一項に記載の吸水性樹脂粉末。
- 請求項13~19の何れか一項に記載の吸水性樹脂粉末と繊維状物とを含有してなる吸収体。
- 請求項20に記載の吸収体であって、請求項13~19の何れか一項に記載の吸水性樹脂粉末と、繊維状物との合計質量に対する当該吸水性樹脂粉末の含有量が40質量%~100質量%であることを特徴とする吸収体。
- 請求項20又は21に記載の吸収体を備えてなる吸収性物品。
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US11559784B2 (en) | 2018-12-11 | 2023-01-24 | Lg Chem, Ltd. | Superabsorbent polymer and preparation method thereof |
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Citations (53)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4783510A (en) | 1986-06-04 | 1988-11-08 | Taiyo Fishery Co., Ltd. | Process for improving a water absorbent polyacrylic acid polymer and an improved polymer produced by said process |
EP0349240A2 (en) | 1988-06-28 | 1990-01-03 | Nippon Shokubai Co., Ltd. | Water-absorbent resin and production process |
US4893999A (en) | 1985-12-18 | 1990-01-16 | Chemische Fabrik Stockhausen Gmbh | Apparatus for the continuous production of polymers and copolymers of water-soluble monomers |
EP0574260A1 (en) | 1992-06-10 | 1993-12-15 | Nippon Shokubai Co., Ltd. | Method for production of hydrophilic resin |
JPH06107800A (ja) | 1992-10-01 | 1994-04-19 | Nippon Shokubai Co Ltd | 粒子状含水ゲル状重合体および吸水性樹脂の製造方法 |
US5562646A (en) | 1994-03-29 | 1996-10-08 | The Proctor & Gamble Company | Absorbent members for body fluids having good wet integrity and relatively high concentrations of hydrogel-forming absorbent polymer having high porosity |
JP2000063527A (ja) * | 1998-08-12 | 2000-02-29 | Nippon Shokubai Co Ltd | 含水ゲル状架橋重合体の細粒化方法 |
US6071976A (en) | 1995-12-27 | 2000-06-06 | Nippon Shokubai Co., Ltd. | Water absorbing agent, manufacturing method thereof, and manufacturing machine thereof |
US6140395A (en) | 1997-12-25 | 2000-10-31 | Nippon Shokubai Co., Ltd. | Method of producing hydrophilic resin |
JP2000302876A (ja) | 1999-02-15 | 2000-10-31 | Nippon Shokubai Co Ltd | 吸水性樹脂粉末の製造方法、吸水性樹脂粉末、およびその用途 |
US6228930B1 (en) | 1997-06-18 | 2001-05-08 | Nippon Shokubai Co., Ltd. | Water-absorbent resin granule-containing composition and production process for water-absorbent resin granule |
US6241928B1 (en) | 1998-04-28 | 2001-06-05 | Nippon Shokubai Co., Ltd. | Method for production of shaped hydrogel of absorbent resin |
US6254990B1 (en) | 1998-02-18 | 2001-07-03 | Nippon Shokubai Co., Ltd. | Surface-crosslinking process for water-absorbent resin |
US6562879B1 (en) | 1999-02-15 | 2003-05-13 | Nippon Shokubai Co., Ltd. | Water-absorbent resin powder and its production process and use |
US6565768B1 (en) | 1998-10-08 | 2003-05-20 | Basf Aktiengesellschaft | Method for producing water-swellable hydorphilic polymers, said polymers and use thereof |
US6599989B2 (en) | 1998-03-03 | 2003-07-29 | Nippon Skokubai Co., Ltd. | Water-absorbent agents containing polycarboxylic amine chelating agents |
US6605673B1 (en) | 1999-03-05 | 2003-08-12 | Stockhausen Gmbh & Co., Kg | Powdery, cross-linked polymers which absorb aqueous liquids and blood, method for the production thereof and their use |
US6620889B1 (en) | 1999-03-05 | 2003-09-16 | Stockhausen Gmbh & Co. Kg | Powdery, crosslinked absorbent polymers, method for the production thereof, and their use |
US6710141B1 (en) | 1999-11-20 | 2004-03-23 | Basf Aktiengesellschaft | Method for continuously producing cross-linked fine-particle geleous polymerizates |
WO2005016393A1 (en) | 2003-07-31 | 2005-02-24 | Kimberly-Clark Worldwide, Inc. | Absorbent materials and articles |
US20050048221A1 (en) | 2003-08-27 | 2005-03-03 | Yoshio Irie | Process for production of surface-treated particulate water-absorbent resin |
US20050070671A1 (en) | 2003-09-19 | 2005-03-31 | Kazushi Torii | Water-absorbent resin having treated surface and process for producing the same |
US6906159B2 (en) | 2000-08-03 | 2005-06-14 | Nippon Shokubai Co., Ltd. | Water-absorbent resin, hydropolymer, process for producing them, and uses of them |
US20050215734A1 (en) | 2004-03-24 | 2005-09-29 | Yorimichi Dairoku | Method for continuous production of water-absorbent resin |
EP1594556A2 (en) | 2003-02-10 | 2005-11-16 | Nippon Shokubai Co., Ltd. | Particulate water-absorbing agent |
US20050288182A1 (en) | 2004-06-18 | 2005-12-29 | Kazushi Torii | Water absorbent resin composition and production method thereof |
US6987171B1 (en) | 1997-05-28 | 2006-01-17 | Tegenero Gmbh | Human CD28 specific monoclonal antibodies for antigen-non-specific activation of T-lymphocytes |
US20060062258A1 (en) | 2004-07-02 | 2006-03-23 | Vanderbilt University | Smith-Purcell free electron laser and method of operating same |
US20060073969A1 (en) | 2003-02-10 | 2006-04-06 | Kazushi Torii | Vater-absorbent resin composition and its production process |
US20060082188A1 (en) | 2004-08-06 | 2006-04-20 | Mitchell Stephen A G | Electromechanical strut |
US20060082189A1 (en) | 2004-10-18 | 2006-04-20 | Faisal Sultan | Upper auxiliary seal with positive attachment configuration |
US20060082197A1 (en) | 2004-10-15 | 2006-04-20 | Brian Luce | Lounge caddy |
US20060111402A1 (en) | 2004-09-30 | 2006-05-25 | Raymond Ng | Novel benzimidazole derivatives useful as selective androgen receptor modulators (SARMS) |
US20060111404A1 (en) | 2004-11-22 | 2006-05-25 | Incyte Corporation | Salts of N-[2-({(3R)-1-[trans-4-hydroxy-4-(6-methoxypyridin-3-yl)-cyclohexyl]pyrrolidin-3-yl}amino)-2-oxoethyl]-3-(trifluoromethyl)benzamide |
US20060111403A1 (en) | 2003-01-28 | 2006-05-25 | Hughes Kenneth A | Cyano anthranilamide insecticides |
US7098284B2 (en) | 2001-01-26 | 2006-08-29 | Nippon Shokubal Co., Ltd | Water-absorbing agent and production process therefor, and water-absorbent structure |
US20060247351A1 (en) | 2005-03-14 | 2006-11-02 | Kazushi Torii | Water-absorbing agent and its production process |
US7157141B2 (en) | 2000-03-31 | 2007-01-02 | Stockhausen Gmbh | Pulverulent polymers crosslinked on the surface |
US20070106013A1 (en) | 2003-06-24 | 2007-05-10 | Yoshifumi Adachi | Water absorbent resin composition and production method thereof |
US20070121037A1 (en) | 2005-11-29 | 2007-05-31 | Casio Computer Co., Ltd. | Homeotropic alignment type semi-transmissive reflective liquid crystal display device |
US20080009843A1 (en) | 2006-06-14 | 2008-01-10 | De La Torre Ralph | Surgical ablation system with chest wall platform |
US20080009842A1 (en) | 2000-12-28 | 2008-01-10 | The General Hospital Corporation | Method and apparatus for emr treatment |
US20080090961A1 (en) | 2006-10-13 | 2008-04-17 | Bayer Materialscience Llc | Impact resistant, flame retardant thermoplastic molding composition |
US7473739B2 (en) | 2004-02-05 | 2009-01-06 | Nippon Shokubai Co., Ltd. | Particulate water absorbent agent and production method thereof, and water absorbent article |
WO2009016055A2 (en) | 2007-07-27 | 2009-02-05 | Basf Se | Water-absorbing polymeric particles and method for the production thereof |
US20090048160A1 (en) | 2007-08-17 | 2009-02-19 | Bannerman Douglas D | Antimicrobial activity of bovine bactericidal/permeability-increasing protein (BPI)-derived peptides against Gram-negative bacterial mastitis isolates |
US20090239966A1 (en) | 2004-12-10 | 2009-09-24 | Nippon Shokubai Co., Ltd. | Method for surface-treatment of water absorbent resin |
US7694900B2 (en) | 2003-04-25 | 2010-04-13 | Nippon Shokubai Co., Ltd. | Method for disintegrating hydrate polymer and method for production of water-absorbent resin |
WO2011034147A1 (ja) | 2009-09-16 | 2011-03-24 | 株式会社日本触媒 | 吸水性樹脂粉末の製造方法 |
WO2011040472A1 (ja) * | 2009-09-29 | 2011-04-07 | 株式会社日本触媒 | 粒子状吸水剤及びその製造方法 |
WO2011078298A1 (ja) | 2009-12-24 | 2011-06-30 | 株式会社日本触媒 | ポリアクリル酸系吸水性樹脂粉末及びその製造方法 |
WO2011126079A1 (ja) | 2010-04-07 | 2011-10-13 | 株式会社日本触媒 | ポリアクリル酸(塩)系吸水性樹脂粉末の製造方法及びポリアクリル酸(塩)系吸水性樹脂粉末 |
JP2012012482A (ja) * | 2010-06-30 | 2012-01-19 | Nippon Shokubai Co Ltd | ポリアクリル酸アンモニウム塩系吸水性樹脂およびその製造方法 |
Family Cites Families (24)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE3150719A1 (de) * | 1981-12-22 | 1983-06-30 | Uniroyal Englebert Reifen GmbH, 5100 Aachen | Schneckenextruder |
GB2150037B (en) * | 1983-11-26 | 1986-11-12 | Farrel Bridge Ltd | Extruder barrel construction |
US6716894B2 (en) * | 2001-07-06 | 2004-04-06 | Nippon Shokubai Co., Ltd. | Water-absorbent resin powder and its production process and uses |
US20090298963A1 (en) | 2004-12-10 | 2009-12-03 | Nippon Shokubai Co., Ltd | Method for production of modified water absorbent resin |
TW200700095A (en) | 2005-02-01 | 2007-01-01 | Basf Ag | Polyamine-coated superabsorbent polymers |
TW200704689A (en) | 2005-02-01 | 2007-02-01 | Basf Ag | Polyamine-coated superabsorbent polymers |
TW200639200A (en) | 2005-02-01 | 2006-11-16 | Basf Ag | Polyamine-coated superabsorbent polymers |
DE102005018922A1 (de) | 2005-04-22 | 2006-10-26 | Stockhausen Gmbh | Mit Polykationen oberflächenbehandeltes wasserabsorbierendes Polymergebilde |
DE102005018924A1 (de) | 2005-04-22 | 2006-10-26 | Stockhausen Gmbh | Wasserabsorbierende Polymergebilde mit verbesserten Absorptionseigenschaften |
WO2006111404A2 (de) | 2005-04-22 | 2006-10-26 | Evonik Stockhausen Gmbh | Oberflächennachvernetzte superabsorber behandelt mit metallsalz und metalloxid |
US7680118B2 (en) | 2006-04-13 | 2010-03-16 | Motorola, Inc. | Method and apparatus for reordering fragments within a MAC layer service data unit within a downlink frame |
FR2903988B1 (fr) | 2006-07-18 | 2008-09-05 | Arkema France | Procede de preparation de polymeres (meth)acryliques |
FR2904059B1 (fr) | 2006-07-21 | 2010-06-18 | Peugeot Citroen Automobiles Sa | Fourchette de maintien d'un porte-injecteur de moteur thermique. |
WO2008026772A1 (en) * | 2006-08-31 | 2008-03-06 | Nippon Shokubai Co., Ltd. | Particulate water absorbing agent and production method thereof |
JP5591448B2 (ja) * | 2006-08-31 | 2014-09-17 | 株式会社日本触媒 | 吸水剤およびその製造方法 |
US9593212B2 (en) | 2006-09-29 | 2017-03-14 | Nippon Shokubai Co., Ltd. | Method for producing water absorbent resin particle |
EP2112172B2 (en) | 2007-01-24 | 2018-10-17 | Nippon Shokubai Co., Ltd. | Particulate water-absorbent polymer and process for production thereof |
WO2009048160A1 (en) | 2007-10-09 | 2009-04-16 | Nippon Shokubai Co., Ltd. | Surface treatment method for water-absorbent resin |
JP5600670B2 (ja) | 2009-02-17 | 2014-10-01 | 株式会社日本触媒 | ポリアクリル酸系吸水性樹脂粉末およびその製造方法 |
EP2527391B1 (en) * | 2010-01-20 | 2023-08-09 | Nippon Shokubai Co., Ltd. | Method for producing water absorbent resin |
US9074030B2 (en) | 2010-06-30 | 2015-07-07 | Nippon Shokubai Co., Ltd. | Polyacrylic acid-type water absorbent resin and method for producing same |
JP5756128B2 (ja) * | 2010-12-17 | 2015-07-29 | 株式会社日本触媒 | ポリアクリル酸(塩)系吸水性樹脂及びその製造方法 |
JP5651513B2 (ja) * | 2011-03-24 | 2015-01-14 | 東洋ゴム工業株式会社 | タイヤ構成部材の成形方法 |
EP3520978B1 (en) * | 2013-08-28 | 2020-11-04 | Nippon Shokubai Co., Ltd. | Polyacrylic acid (salt)-based water absorbent resin powder |
-
2014
- 2014-08-28 US US14/914,146 patent/US9533433B2/en active Active
- 2014-08-28 JP JP2015534291A patent/JP5989913B2/ja active Active
- 2014-08-28 CN CN201711088569.8A patent/CN107936189B/zh active Active
- 2014-08-28 CN CN201480047461.2A patent/CN105492504B/zh active Active
- 2014-08-28 KR KR1020167007199A patent/KR102297636B1/ko active IP Right Grant
- 2014-08-28 EP EP18180781.9A patent/EP3401070B1/en active Active
- 2014-08-28 EP EP14840421.3A patent/EP3040362B1/en active Active
- 2014-08-28 WO PCT/JP2014/072620 patent/WO2015030129A1/ja active Application Filing
Patent Citations (56)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4893999A (en) | 1985-12-18 | 1990-01-16 | Chemische Fabrik Stockhausen Gmbh | Apparatus for the continuous production of polymers and copolymers of water-soluble monomers |
US4783510A (en) | 1986-06-04 | 1988-11-08 | Taiyo Fishery Co., Ltd. | Process for improving a water absorbent polyacrylic acid polymer and an improved polymer produced by said process |
EP0349240A2 (en) | 1988-06-28 | 1990-01-03 | Nippon Shokubai Co., Ltd. | Water-absorbent resin and production process |
EP0574260A1 (en) | 1992-06-10 | 1993-12-15 | Nippon Shokubai Co., Ltd. | Method for production of hydrophilic resin |
JPH06107800A (ja) | 1992-10-01 | 1994-04-19 | Nippon Shokubai Co Ltd | 粒子状含水ゲル状重合体および吸水性樹脂の製造方法 |
US5669894A (en) | 1994-03-29 | 1997-09-23 | The Procter & Gamble Company | Absorbent members for body fluids having good wet integrity and relatively high concentrations of hydrogel-forming absorbent polymer |
US5562646A (en) | 1994-03-29 | 1996-10-08 | The Proctor & Gamble Company | Absorbent members for body fluids having good wet integrity and relatively high concentrations of hydrogel-forming absorbent polymer having high porosity |
US6071976A (en) | 1995-12-27 | 2000-06-06 | Nippon Shokubai Co., Ltd. | Water absorbing agent, manufacturing method thereof, and manufacturing machine thereof |
US6987171B1 (en) | 1997-05-28 | 2006-01-17 | Tegenero Gmbh | Human CD28 specific monoclonal antibodies for antigen-non-specific activation of T-lymphocytes |
US6228930B1 (en) | 1997-06-18 | 2001-05-08 | Nippon Shokubai Co., Ltd. | Water-absorbent resin granule-containing composition and production process for water-absorbent resin granule |
US6140395A (en) | 1997-12-25 | 2000-10-31 | Nippon Shokubai Co., Ltd. | Method of producing hydrophilic resin |
US6254990B1 (en) | 1998-02-18 | 2001-07-03 | Nippon Shokubai Co., Ltd. | Surface-crosslinking process for water-absorbent resin |
US6599989B2 (en) | 1998-03-03 | 2003-07-29 | Nippon Skokubai Co., Ltd. | Water-absorbent agents containing polycarboxylic amine chelating agents |
US6241928B1 (en) | 1998-04-28 | 2001-06-05 | Nippon Shokubai Co., Ltd. | Method for production of shaped hydrogel of absorbent resin |
JP2000063527A (ja) * | 1998-08-12 | 2000-02-29 | Nippon Shokubai Co Ltd | 含水ゲル状架橋重合体の細粒化方法 |
US6565768B1 (en) | 1998-10-08 | 2003-05-20 | Basf Aktiengesellschaft | Method for producing water-swellable hydorphilic polymers, said polymers and use thereof |
US6562879B1 (en) | 1999-02-15 | 2003-05-13 | Nippon Shokubai Co., Ltd. | Water-absorbent resin powder and its production process and use |
JP2000302876A (ja) | 1999-02-15 | 2000-10-31 | Nippon Shokubai Co Ltd | 吸水性樹脂粉末の製造方法、吸水性樹脂粉末、およびその用途 |
US6605673B1 (en) | 1999-03-05 | 2003-08-12 | Stockhausen Gmbh & Co., Kg | Powdery, cross-linked polymers which absorb aqueous liquids and blood, method for the production thereof and their use |
US6620889B1 (en) | 1999-03-05 | 2003-09-16 | Stockhausen Gmbh & Co. Kg | Powdery, crosslinked absorbent polymers, method for the production thereof, and their use |
US6710141B1 (en) | 1999-11-20 | 2004-03-23 | Basf Aktiengesellschaft | Method for continuously producing cross-linked fine-particle geleous polymerizates |
US7157141B2 (en) | 2000-03-31 | 2007-01-02 | Stockhausen Gmbh | Pulverulent polymers crosslinked on the surface |
US6906159B2 (en) | 2000-08-03 | 2005-06-14 | Nippon Shokubai Co., Ltd. | Water-absorbent resin, hydropolymer, process for producing them, and uses of them |
US7091253B2 (en) | 2000-08-03 | 2006-08-15 | Nippon Shokubai Co., Ltd. | Water-absorbent resin, hydropolymer, process for producing them, and uses of them |
US20080009842A1 (en) | 2000-12-28 | 2008-01-10 | The General Hospital Corporation | Method and apparatus for emr treatment |
US7098284B2 (en) | 2001-01-26 | 2006-08-29 | Nippon Shokubal Co., Ltd | Water-absorbing agent and production process therefor, and water-absorbent structure |
US20060111403A1 (en) | 2003-01-28 | 2006-05-25 | Hughes Kenneth A | Cyano anthranilamide insecticides |
US20060073969A1 (en) | 2003-02-10 | 2006-04-06 | Kazushi Torii | Vater-absorbent resin composition and its production process |
US7638570B2 (en) | 2003-02-10 | 2009-12-29 | Nippon Shokubai Co., Ltd. | Water-absorbing agent |
EP1594556A2 (en) | 2003-02-10 | 2005-11-16 | Nippon Shokubai Co., Ltd. | Particulate water-absorbing agent |
US7694900B2 (en) | 2003-04-25 | 2010-04-13 | Nippon Shokubai Co., Ltd. | Method for disintegrating hydrate polymer and method for production of water-absorbent resin |
US20070106013A1 (en) | 2003-06-24 | 2007-05-10 | Yoshifumi Adachi | Water absorbent resin composition and production method thereof |
WO2005016393A1 (en) | 2003-07-31 | 2005-02-24 | Kimberly-Clark Worldwide, Inc. | Absorbent materials and articles |
US20050048221A1 (en) | 2003-08-27 | 2005-03-03 | Yoshio Irie | Process for production of surface-treated particulate water-absorbent resin |
US20050070671A1 (en) | 2003-09-19 | 2005-03-31 | Kazushi Torii | Water-absorbent resin having treated surface and process for producing the same |
US7473739B2 (en) | 2004-02-05 | 2009-01-06 | Nippon Shokubai Co., Ltd. | Particulate water absorbent agent and production method thereof, and water absorbent article |
US20050215734A1 (en) | 2004-03-24 | 2005-09-29 | Yorimichi Dairoku | Method for continuous production of water-absorbent resin |
US20050288182A1 (en) | 2004-06-18 | 2005-12-29 | Kazushi Torii | Water absorbent resin composition and production method thereof |
US20060062258A1 (en) | 2004-07-02 | 2006-03-23 | Vanderbilt University | Smith-Purcell free electron laser and method of operating same |
US20060082188A1 (en) | 2004-08-06 | 2006-04-20 | Mitchell Stephen A G | Electromechanical strut |
US20060111402A1 (en) | 2004-09-30 | 2006-05-25 | Raymond Ng | Novel benzimidazole derivatives useful as selective androgen receptor modulators (SARMS) |
US20060082197A1 (en) | 2004-10-15 | 2006-04-20 | Brian Luce | Lounge caddy |
US20060082189A1 (en) | 2004-10-18 | 2006-04-20 | Faisal Sultan | Upper auxiliary seal with positive attachment configuration |
US20060111404A1 (en) | 2004-11-22 | 2006-05-25 | Incyte Corporation | Salts of N-[2-({(3R)-1-[trans-4-hydroxy-4-(6-methoxypyridin-3-yl)-cyclohexyl]pyrrolidin-3-yl}amino)-2-oxoethyl]-3-(trifluoromethyl)benzamide |
US20090239966A1 (en) | 2004-12-10 | 2009-09-24 | Nippon Shokubai Co., Ltd. | Method for surface-treatment of water absorbent resin |
US20060247351A1 (en) | 2005-03-14 | 2006-11-02 | Kazushi Torii | Water-absorbing agent and its production process |
US20070121037A1 (en) | 2005-11-29 | 2007-05-31 | Casio Computer Co., Ltd. | Homeotropic alignment type semi-transmissive reflective liquid crystal display device |
US20080009843A1 (en) | 2006-06-14 | 2008-01-10 | De La Torre Ralph | Surgical ablation system with chest wall platform |
US20080090961A1 (en) | 2006-10-13 | 2008-04-17 | Bayer Materialscience Llc | Impact resistant, flame retardant thermoplastic molding composition |
WO2009016055A2 (en) | 2007-07-27 | 2009-02-05 | Basf Se | Water-absorbing polymeric particles and method for the production thereof |
US20090048160A1 (en) | 2007-08-17 | 2009-02-19 | Bannerman Douglas D | Antimicrobial activity of bovine bactericidal/permeability-increasing protein (BPI)-derived peptides against Gram-negative bacterial mastitis isolates |
WO2011034147A1 (ja) | 2009-09-16 | 2011-03-24 | 株式会社日本触媒 | 吸水性樹脂粉末の製造方法 |
WO2011040472A1 (ja) * | 2009-09-29 | 2011-04-07 | 株式会社日本触媒 | 粒子状吸水剤及びその製造方法 |
WO2011078298A1 (ja) | 2009-12-24 | 2011-06-30 | 株式会社日本触媒 | ポリアクリル酸系吸水性樹脂粉末及びその製造方法 |
WO2011126079A1 (ja) | 2010-04-07 | 2011-10-13 | 株式会社日本触媒 | ポリアクリル酸(塩)系吸水性樹脂粉末の製造方法及びポリアクリル酸(塩)系吸水性樹脂粉末 |
JP2012012482A (ja) * | 2010-06-30 | 2012-01-19 | Nippon Shokubai Co Ltd | ポリアクリル酸アンモニウム塩系吸水性樹脂およびその製造方法 |
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JP7335050B2 (ja) | 2019-11-21 | 2023-08-29 | エルジー・ケム・リミテッド | 高吸水性含水ゲル複合細切装置 |
JP7058787B1 (ja) | 2021-05-12 | 2022-04-22 | 株式会社日本触媒 | ポリ(メタ)アクリル酸(塩)系吸水性樹脂、及び吸収体 |
JP2022175091A (ja) * | 2021-05-12 | 2022-11-25 | 株式会社日本触媒 | ポリ(メタ)アクリル酸(塩)系吸水性樹脂、及び吸収体 |
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US9533433B2 (en) | 2017-01-03 |
EP3040362A4 (en) | 2017-09-06 |
CN105492504A (zh) | 2016-04-13 |
CN107936189A (zh) | 2018-04-20 |
US20160207226A1 (en) | 2016-07-21 |
EP3040362A1 (en) | 2016-07-06 |
KR102297636B1 (ko) | 2021-09-06 |
EP3401070A1 (en) | 2018-11-14 |
KR20160048842A (ko) | 2016-05-04 |
CN107936189B (zh) | 2021-06-01 |
CN105492504B (zh) | 2017-12-19 |
EP3040362B1 (en) | 2018-08-08 |
EP3401070B1 (en) | 2021-04-21 |
JPWO2015030129A1 (ja) | 2017-03-02 |
JP5989913B2 (ja) | 2016-09-07 |
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