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WO2021246244A1 - Procédé de production de particule de résine absorbant d'eau - Google Patents

Procédé de production de particule de résine absorbant d'eau Download PDF

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Publication number
WO2021246244A1
WO2021246244A1 PCT/JP2021/019823 JP2021019823W WO2021246244A1 WO 2021246244 A1 WO2021246244 A1 WO 2021246244A1 JP 2021019823 W JP2021019823 W JP 2021019823W WO 2021246244 A1 WO2021246244 A1 WO 2021246244A1
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Prior art keywords
polymer
minutes
temperature
hydrogel
mixture
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English (en)
Japanese (ja)
Inventor
志保 岡澤
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Sumitomo Seika Chemicals Co Ltd
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Sumitomo Seika Chemicals Co Ltd
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Priority to JP2022528762A priority Critical patent/JP7783811B2/ja
Publication of WO2021246244A1 publication Critical patent/WO2021246244A1/fr
Anticipated expiration legal-status Critical
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    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F220/00—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 a salt, anhydride ester, amide, imide or nitrile thereof
    • C08F220/02—Monocarboxylic acids having less than ten carbon atoms; Derivatives thereof
    • C08F220/04—Acids; Metal salts or ammonium salts thereof
    • C08F220/06—Acrylic acid; Methacrylic acid; Metal salts 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
    • C08J3/00—Processes of treating or compounding macromolecular substances
    • C08J3/12—Powdering or granulating

Definitions

  • the present disclosure relates to a method for producing water-absorbent resin particles.
  • the water-absorbent resin particles that can be used for absorbent articles such as sanitary articles can be produced by a method comprising pulverizing or coarsely crushing a massive hydrogel-like polymer formed by polymerization of monomers.
  • Patent Document 1 There is (for example, Patent Document 1).
  • Water can be efficiently removed from the hydrogel polymer by coarsely crushing the hydrogel polymer so that a crushed product containing a structure having a size as small as possible is formed before drying. ..
  • a coarsely crushed product containing a structure having a small size is formed, the dissolved content of the obtained water-absorbent resin particles, especially in physiological saline, tends to increase. rice field.
  • one aspect of the present disclosure is that when the water-absorbent resin particles are produced by a method including coarsely crushing the water-containing gel-like polymer so as to form a coarsely crushed product containing a structure having a small size, the water-absorbent resin particles are produced.
  • the present invention relates to a method for reducing the dissolved content of resin particles in physiological saline.
  • One aspect of the present disclosure provides a method of producing water-absorbent resin particles containing polymer particles.
  • the method is a polymer of the monomer by forming a mixture containing the monomer and water in which the monomer is dissolved in a reaction vessel and polymerizing the monomer in the mixture.
  • a hydrogel-like polymer which is a gelled mixture containing the above is formed in the reaction vessel, and the massive hydrogel-like polymer taken out from the reaction vessel is coarsely crushed to form a coarse crushed product. It includes forming polymer particles from the coarsely crushed material by a method including removal of water and pulverization.
  • the lumpy hydrogel polymer is coarsely crushed so as to form the coarse crushed product containing a plurality of structures having a shape capable of passing through a circular hole having a diameter of 7 mm.
  • the elapsed time from the time when the temperature of the mixture reaches the maximum value T max during the polymerization of the monomer to the time when the coarse crushing of the hydrogel-like polymer is started is t.
  • the temperature of the hydrogel polymer at the time when coarse crushing of the hydrogel polymer is started is T.
  • t is 15 minutes or less
  • the dissolved content of the polymer particles obtained from the crude product in a physiological saline solution at 25 ° C. is smaller than the value when t is 30 minutes and T is X.
  • the time selected for. X is a temperature within the range of 70 ⁇ 3 ° C.
  • T is a temperature within the range of X ⁇ 25 ° C.
  • the method according to one aspect of the present disclosure in the case of producing water-absorbent resin particles by a method including coarsely crushing a hydrogel-like polymer so as to form a crushed product containing a structure having a small size. , The dissolved content of the water-absorbent resin particles in physiological saline can be reduced.
  • the present invention is not limited to the following embodiments.
  • (meth) acrylic means both acrylic and methacryl.
  • acrylate and “methacrylate” are also referred to as “(meth) acrylate”.
  • (Poly) means both with and without the “poly” prefix.
  • the upper or lower limit of the numerical range at one stage may be optionally combined with the upper or lower limit of the numerical range at another stage.
  • the upper limit value or the lower limit value of the numerical range may be replaced with the value shown in the examples.
  • Water-soluble means that it exhibits a solubility in water of 5% by mass or more at 25 ° C. The materials exemplified in the present specification may be used alone or in combination of two or more.
  • Saline means a 0.9% by mass sodium chloride aqueous solution.
  • An example of a method for producing water-absorbent resin particles is simply by forming a mixture containing a monomer and water in which the monomer is dissolved in a reaction vessel and polymerizing the monomer in the mixture.
  • a hydrogel-like polymer which is a gelled mixture containing a polymer of a monomer, is formed in a reaction vessel, and a massive hydrogel-like polymer taken out from the reaction vessel is coarsely crushed to form a coarse crushed product. And the formation of polymer particles from the crushed material.
  • the water-absorbent resin particles produced include polymer particles containing a polymer.
  • the mixture before the polymerization reaction can be water and a monomer aqueous solution containing a monomer dissolved in water.
  • the concentration of the monomer in the mixture (aqueous monomer solution) before the polymerization reaction may be, for example, 20 to 50% by mass, 25 to 45% by mass, or 30 to 40% by mass based on the mass of the mixture.
  • the monomer is a compound that forms a polymer that imparts water absorption to the polymer particles and the water-absorbent resin particles by polymerization.
  • the monomer may be an ethylenically unsaturated monomer.
  • the polymer formed may be a crosslinked polymer.
  • the ethylenically unsaturated monomer is, for example, (meth) acrylic acid and a salt thereof, 2- (meth) acrylamide-2-methylpropanesulfonic acid and a salt thereof, (meth) acrylamide, N, N-dimethyl (meth).
  • the amino group may be quaternized.
  • the mixture for polymerization may contain a monomer other than the ethylenically unsaturated monomer.
  • the proportion of ethylenically unsaturated monomers may be 70-100 mol% with respect to the total amount of the monomers in the mixture.
  • the mixture for polymerization may further contain a radical polymerization initiator.
  • the radical polymerization initiator may contain a persulfate, an azo compound, a peroxide or a combination thereof.
  • the amount of the radical polymerization initiator may be 0.01 to 15 mmol per mole of the monomer.
  • persulfate examples include potassium persulfate, ammonium persulfate, and sodium persulfate.
  • azo compounds examples include 2,2'-azobis (2-amidinopropane) dihydrochloride, 2,2'-azobis ⁇ 2- [1- (2-hydroxyethyl) -2-imidazolin-2-yl]. Propane ⁇ dihydrochloride, 2,2'-azobis [N- (2-carboxyethyl) -2-methylpropionamidine] tetrahydrate, 2,2'-azobis [2- (2-imidazolin-2-yl) ) Propane] dihydrochloride, 2,2'-azobis [2- (N-phenylamidino) propane] dihydrochloride, 2,2'-azobis [2- (N-allylamidino) propane] dihydrochloride, 2 , 2'-azobis ⁇ 2-methyl-N- [1,1-bis (hydroxymethyl) -2-hydroxyethyl] propionamide ⁇ , 2,2'-azobis [2-methyl-N- (2-hydroxyethyl] ) -Propionamide], and 4,
  • the radical polymerization initiators are 2,2'-azobis (2-amidinopropane) dihydrochloride, 2,2'-azobis ⁇ 2- [1- (2-hydroxy). Ethyl) -2-imidazolin-2-yl] propane ⁇ dihydrochloride, 2,2'-azobis [N- (2-carboxyethyl) -2-methylpropionamidine] tetrahydrate, and 2,2'- It may contain at least one azo compound selected from azobis [2- (2-imidazolin-2-yl) propane] dihydrochloride.
  • peroxides examples include methyl ethyl ketone peroxide, methyl isobutyl ketone peroxide, di-t-butyl peroxide, t-butyl cumyl peroxide, t-butyl peroxyacetate, t-butyl peroxyisobutyrate, t. -Butyl peroxypivalate and hydrogen peroxide can be mentioned.
  • the monomer aqueous solution may further contain a chain transfer agent.
  • the chain transfer agent may include, for example, hypophosphorous acid, phosphorous acid or a combination thereof.
  • the monomer aqueous solution may contain an internal cross-linking agent.
  • an internal cross-linking agent a hydrogel-like polymer containing a crosslinked polymer crosslinked by an internal crosslinking agent is formed.
  • the amount of the internal cross-linking agent may be 0.002 to 0.04 mmol per mole of the monomer.
  • the internal cross-linking agent may be a compound having two or more reactive functional groups (for example, a polymerizable unsaturated group).
  • the internal cross-linking agent may contain a compound having a (meth) acrylic group, an allyl group, an epoxy group, or an amino group as a reactive functional group.
  • examples of compounds having a (meth) acrylic group include (poly) ethylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, and N, N'-methylenebis (meth) acrylamide.
  • Examples of compounds having an allyl group include triallylamine.
  • Examples of compounds having an epoxy group include (poly) ethylene glycol diglycidyl ether, (poly) propylene glycol diglycidyl ether, (poly) glycerin diglycidyl ether, (poly) glycerin polyglycidyl ether and epichlorohydrin. Will be.
  • Examples of compounds having an amino group include triethylenetetramine, ethylenediamine, and hexamethylenediamine.
  • the reaction vessel is not particularly limited, but may be, for example, a vessel made of stainless steel, ceramics, synthetic resin, or steel.
  • the reaction vessel may be provided on the belt conveyor.
  • the depth (or thickness) of the mixture (monomer aqueous solution) formed in the reaction vessel may be, for example, 10 to 50 mm, 10 to 40 mm, or 15 to 35 mm.
  • the maximum width of the mixture (monomer aqueous solution) formed in the reaction vessel in the horizontal direction may be, for example, 50 to 800 mm.
  • the temperature of the mixture before the temperature rises due to the polymerization reaction may be, for example, 0 ° C. or higher and 50 ° C. or lower, 40 ° C. or lower or 30 ° C. or lower, and 10 ° C. or higher and 50 ° C. or lower, 40 ° C. or lower or 30 ° C. or lower. It may be as follows.
  • T max may be, for example, 60 ° C. or higher and 100 ° C. or lower, 95 ° C. or lower or 90 ° C. or lower, 70 ° C. or higher and 100 ° C. or lower, 95 ° C. or lower or 90 ° C. or lower, and 75 ° C. or higher. It may be 100 ° C. or lower, 95 ° C. or lower, or 90 ° C. or lower.
  • the formed massive hydrogel polymer is taken out of the reaction vessel and subjected to the subsequent coarse grinding step.
  • the hydrogel-like polymer may be held in the reaction vessel at a temperature equal to or higher than the temperature T described later, and then taken out from the reaction vessel.
  • the hydrogel-like polymer taken out from the reaction vessel may be divided if necessary to obtain a plurality of lumps having a size small to some extent. In that case, the lump is subjected to the coarse crushing process.
  • the minimum width of the lump may be, for example, about 5 to 70 mm.
  • a crushed product containing a structure having a small size below a certain level is formed. More specifically, the hydrogel polymer is coarsely crushed so as to form a crushed product containing a plurality of structures having a shape capable of passing through a circular hole having a diameter of 7 mm.
  • the coarsening apparatus for coarsely crushing the hydrogel-like polymer include kneaders (for example, pressurized kneaders, double-armed kneaders), meat choppers, cutter mills, and pharmacomills.
  • the crushed product can be an aggregate composed of a plurality of structures.
  • the structure constituting the coarsely crushed product can be, for example, an elongated structure, a granular structure (particle), or a combination thereof.
  • the elongated structure may be bent, and if its maximum width is 7 mm or less, it can be said that the elongated structure has a shape capable of passing through a circular hole having a diameter of 7 mm.
  • the granular structure (particle) may be irregular or may have a shape that allows it to pass through a circular hole having a diameter of 7 mm while changing its direction.
  • the coarsely crushed material composed of a plurality of elongated structures is formed by, for example, a crushing device having a discharge hole for discharging the crushed material (for example, a meat chopper).
  • a crushing device having a discharge hole for discharging the crushed material (for example, a meat chopper).
  • a coarsely crushed product containing an elongated structure that can pass through a circular hole having a diameter of 7 mm is usually formed.
  • the coarse grus composed of granular structures is formed, for example, by a kneader.
  • the elapsed time from the time when the temperature of the mixture reaches the maximum value T max during the polymerization of the monomers to the time when the coarse crushing of the hydrogel-like polymer is started is t.
  • the temperature of the hydrogel polymer at the time when the coarse crushing of the hydrogel polymer is started is T.
  • the "time point at which coarse crushing of the hydrogel-like polymer is started” excludes the loss due to removal from the reaction vessel, etc. of the hydrogel-like polymer formed in one reaction vessel. It means the time when stress is started to be applied to the part by the crusher.
  • the portion of the hydrogel-like polymer formed in one reaction vessel to be coarsely crushed is charged into the kneading chamber while rotating the roll.
  • the time at which the water-containing gel-like polymer begins to be coarsely crushed is considered to be the time at which coarse crushing of the hydrogel polymer is started.
  • a kneader having a kneading chamber equipped with blades is used, the water-containing gel-like polymer formed in one reaction vessel starts to be charged into the kneading chamber when the portion to be coarsely crushed begins to be charged into the kneading chamber. It is considered to be the time when the coarse crushing of the state polymer is started. Not all the hydrogel-like polymers formed in one reaction vessel need to be subjected to coarse grinding.
  • the elapsed time t is determined based on the dissolved content of the polymer particles obtained from the crude product in physiological saline at 25 ° C. within the range of 15 minutes or less. More specifically, the dissolved content is smaller than the dissolved content (standard dissolved content) of the polymer particles obtained from the crude product when t is 30 minutes and T is X in physiological saline at 25 ° C. T is selected so that X is a temperature arbitrarily selected in the range of 70 ⁇ 3 ° C., and may be 68 ° C., for example.
  • a dispersion consisting of 500 g of the physiological saline solution at 25 ° C. and 2 g of the polymer particles dispersed in the physiological saline solution is rotated at 600 rpm in a beaker having a capacity of 500 mL.
  • the elapsed time t is selected so that the dissolved content of the polymer particles obtained from the crude product in physiological saline at 25 ° C. is 90% or less, 85% or less, or 80% or less with respect to the standard dissolved content. It may be the time that was set.
  • the dissolved content of the polymer particles obtained from the coarsely crushed product in physiological saline at 25 ° C. may be 50% or more with respect to the standard dissolved content.
  • the elapsed time t may be 14 minutes or less, 13 minutes or less, 12 minutes or less, 11 minutes or less, 10 minutes or less, or less than 10 minutes.
  • the elapsed time t is 1 to 15 minutes, 2 to 15 minutes, 3 to 15 minutes, 4 to 15 minutes, 1 to 14 minutes, 2 to 14 minutes, 3 to 14 minutes, 4 to 14 minutes, 1 to 13 minutes, 2-13 minutes, 3-13 minutes, 4-13 minutes, 1-12 minutes, 2-12 minutes, 3-12 minutes, 4-12 minutes, 1-11 minutes, 2-11 minutes, 3-11 minutes, 4-11 minutes, 1-10 minutes, 2-10 minutes, 3-10 minutes, 4-10 minutes, 1 minute or more and less than 10 minutes, 2 minutes or more and less than 10 minutes, 3 minutes or more and less than 10 minutes, or 4 minutes or more. It may be less than 10 minutes.
  • the temperature T of the hydrogel polymer at the time when the coarse crushing of the hydrogel polymer is started is a temperature within the range of X ⁇ 25 ° C.
  • T is within the range of X ⁇ 25 ° C.
  • the elapsed time t in which the dissolved content is smaller than the reference dissolved content can be easily selected.
  • T may be in the range of X ⁇ 20 ° C., X ⁇ 10 ° C., or X ⁇ 5 ° C.
  • the temperatures of the mixture and the water-containing gel-like polymer are always kept. It may be kept at 40 ° C. or higher, or T or higher. As a result, the effect of reducing the dissolved content can be obtained more remarkably. If necessary, the hydrogel polymer may be heated in order to keep the temperature at 40 ° C. or higher.
  • Polymer particles can be obtained from the coarsely crushed material by a method including drying and crushing. More specifically, polymer particles can be obtained by a method including drying the coarsely crushed product to obtain a dried product and pulverizing the dried product.
  • the moisture content of the dried product obtained by drying may be, for example, 20% by mass or less, 10% by mass or less, or 5% by mass or less.
  • the water content of the dried product here means the ratio of the water content in the polymer particles based on the total mass of the dried product containing water. Normally, when a dried product containing water is heated at 200 ° C. for 2 hours, the difference in mass of the dried product before and after heating can be regarded as the amount of water in the dried product.
  • the drying method may be a general method such as natural drying, heat drying, blast drying, freeze drying or a combination thereof.
  • the crushed product may be dried under normal pressure or reduced pressure.
  • the heating temperature for drying under normal pressure may be 70 to 250 ° C. or 80 to 200 ° C.
  • the method of crushing the dried product is not particularly limited.
  • a crusher such as a centrifugal crusher, a roller mill, a stamp mill, a jet mill, a high-speed rotary crusher, and a container-driven mill can be used to crush the dried product.
  • the powder of the polymer particles obtained by pulverization may be classified.
  • Classification means an operation of dividing a particle group (powder) into two or more particle groups having different particle size distributions. A part of the powder of the polymer particles after the classification may be pulverized and classified again.
  • the classification method is not particularly limited, but may be, for example, screen classification or wind power classification.
  • Screen classification is a method of classifying particles on a screen into particles that pass through the mesh of the screen and particles that do not pass through the screen by vibrating the screen. Screen classification can be performed using, for example, a vibrating sieve, a rotary shifter, a cylindrical stirring sieve, a blower shifter, or a low-tap shaker.
  • Wind power classification is a method of classifying particles using the flow of air.
  • the medium particle size of the polymer particles obtained by pulverization and, if necessary, classification may be, for example, 200 to 500 ⁇ m.
  • the medium particle size of the polymer particles before being mixed with the surface cross-linking agent solution described later may be, for example, 200 to 500 ⁇ m.
  • the polymer particles may be surface-crosslinked with a surface-crosslinking agent.
  • a surface-crosslinking agent By surface cross-linking, the polymer near the surface of the polymer particles is cross-linked by the surface cross-linking agent.
  • the polymer particles can be surface-crosslinked by heating a mixture of the polymer particle powder and the surface cross-linking agent solution. The above-mentioned dissolution for selecting the elapsed time t is measured using the polymer particles before surface cross-linking.
  • the surface cross-linking agent solution can be water and a solution containing a surface cross-linking agent dissolved in water.
  • the solvent contained in the surface cross-linking agent solution may be substantially only water.
  • the ratio of the solvent other than water may be 10% by mass or less, 5% by mass or less, or 1% by mass or less based on the mass of the surface cross-linking agent solution.
  • Examples of surface cross-linking agents include alkylene carbonate compounds such as ethylene carbonate; ethylene glycol, propylene glycol, 1,4-butanediol, trimethylolpropane, glycerin, polyoxyethylene glycol, polyoxypropylene glycol, polyglycerin and the like.
  • alkylene carbonate compounds such as ethylene carbonate; ethylene glycol, propylene glycol, 1,4-butanediol, trimethylolpropane, glycerin, polyoxyethylene glycol, polyoxypropylene glycol, polyglycerin and the like.
  • Polypoly compounds poly (poly) ethylene glycol diglycidyl ether, (poly) glycerin diglycidyl ether, (poly) glycerin triglycidyl ether, trimethylolpropane triglycidyl ether (poly) propylene glycol polyglycidyl ether, and (poly)
  • Polyglycidyl compounds such as ethers; haloepoxy compounds such as epichlorohydrin, epibromhydrin, and ⁇ -methylepicrolhydrin; isocyanate compounds such as 2,4-tolylene diisocyanate, and hexamethylene diisocyanates; 3-methyl-3-oxetanemethanol, Oxetane compounds such as 3-ethyl-3-oxetan methanol, 3-butyl-3-oxetane methanol, 3-methyl-3-oxetane ethanol, 3-ethyl-3-oxetane ethanol, and 3-butyl-3-oxetane ethanol; Oxazoline compounds such as 1,2-ethylenebisoxazoline; hydroxyalkylamide compounds such as bis [N, N-di ( ⁇ -hydroxyethyl)] adipamide can be mentioned.
  • the surface cross-linking agent may contain an alkylene carbonate compound, a polyol compound, or a combination thereof.
  • the ratio of the alkylene carbonate compound in the surface cross-linking agent is 50 to 100% by mass, 60 to 100% by mass, 70 to 100% by mass, 80 to 100% by mass, or 90 to 100% by mass based on the total mass of the surface cross-linking agent. May be.
  • the amount of the surface cross-linking agent is 0.001 to 0.10 mol, 0 per mol of the monomer unit constituting the polymer in the polymer particles. It may be .005 to 0.05, or 0.01 to 0.02 mol.
  • the heating temperature and heating time for surface cross-linking are adjusted so that the cross-linking reaction proceeds appropriately in consideration of the type of surface cross-linking agent and the like.
  • the heating temperature for surface cross-linking may be 80 to 200 ° C.
  • the heating time for surface cross-linking may be, for example, 5 to 90 minutes.
  • the surface-crosslinked polymer particles may be further dried or classified if necessary.
  • the polymer particles may be used as they are as the water-absorbent resin particles, or the inorganic particles may be attached to the surface of the polymer particles, for example. That is, the water-absorbent resin particles may contain the polymer particles and the inorganic particles adhering to the surface of the polymer particles.
  • examples of inorganic particles include silica particles such as amorphous silica.
  • the produced water-absorbent resin particles are used to form an absorbent body constituting an absorbent article such as a diaper, for example.
  • a lumpy hydrogel polymer which is a gelled mixture was taken out of the stainless steel bat and immediately cut to a width of about 6 cm.
  • the cut water-containing gel polymer was coarsely crushed by quickly throwing it into a kneading chamber equipped with a roller of a meat chopper (manufactured by Kiren Royal Co., Ltd., 12VR-750SDX) while rotating the roller.
  • the elapsed time from when the temperature of the mixture in the polymerization reaction reached the maximum value to when the hydrogel polymer was started to be charged into the meat chopper was 4 minutes.
  • the temperature of the hydrogel polymer immediately before being charged into the meat chopper was 73 ° C.
  • a crushed product containing an elongated structure of a hydrogel-like polymer was discharged from a plurality of circular discharge holes of a plate mounted at the end of the kneading chamber of the meat chopper.
  • the diameter of the discharge hole was 6.4 mm.
  • coarse crushing with a meat chopper was continued for 3 minutes.
  • the obtained coarse crushed product was an aggregate formed by a plurality of elongated structures having a width of 4 to 6 mm.
  • the obtained coarse crushed product was spread out on a wire mesh having an opening of 0.8 cm ⁇ 0.8 cm and dried by hot air drying at 180 ° C. for 30 minutes to obtain a dried product.
  • the dried product was pulverized using a centrifugal pulverizer (Retsch, ZM200, screen diameter 1 mm, 6000 rpm).
  • the powder obtained by pulverization was sieved by shaking for 1 minute using a sieve having an opening of 850 ⁇ m and a sieve having an opening of 180 ⁇ m.
  • the polymer particles that passed through a sieve with an opening of 850 ⁇ m and remained on the sieve with an opening of 180 ⁇ m were recovered.
  • Example 2 By the polymerization reaction in the mixture by the same operation as in Example 1, a lumpy hydrogel polymer was formed in the stainless steel vat. Twelve minutes after the completion of the dropping of the L-ascorbic acid aqueous solution, the temperature of the mixture reached the maximum value of 81 ° C. Within 30 seconds after the thermometer showed the maximum value, after confirming that the thermometer showed a temperature 0.1 ° C lower than the maximum value, the stainless steel vat containing the hydrogel polymer was placed at 80 ° C. Soaked in a water bath. After allowing the hydrogel polymer to stand in the water bath for 6 minutes, the hydrogel polymer was taken out from the stainless steel vat and immediately cut into a width of about 6 cm.
  • the cut water-containing gel polymer was coarsely crushed using a meat chopper by the same operation as in Example 1.
  • the elapsed time from the maximum temperature of the mixture in the polymerization reaction to the start of charging the hydrogel polymer into the meat chopper was 10 minutes.
  • the temperature of the hydrogel polymer immediately before being charged into the kneading chamber of the meat chopper was 68 ° C. From the obtained coarse crushed product, polymer particles were obtained by drying, pulverizing and classifying in the same manner as in Example 1.
  • Example 3 By the polymerization reaction in the mixture by the same operation as in Example 1, a lumpy hydrogel polymer was formed in the stainless steel vat. Twelve minutes after the completion of the dropping of the L-ascorbic acid aqueous solution, the temperature of the mixture reached the maximum value of 83 ° C. Within 30 seconds after the thermometer showed the maximum value, after confirming that the thermometer showed a temperature 0.1 ° C lower than the maximum value, the stainless steel vat containing the hydrogel polymer was placed at 80 ° C. Soaked in a water bath. After allowing the hydrogel polymer to stand in the water bath for 11 minutes, the hydrogel polymer was taken out from the stainless steel vat and immediately cut into a width of about 6 cm.
  • the cut water-containing gel polymer was coarsely crushed using a meat chopper by the same operation as in Example 1.
  • the time from when the temperature of the mixture in the polymerization reaction reached the maximum value to when the hydrogel-like polymer was started to be put into the kneading chamber of the meat chopper was 15 minutes.
  • the temperature of the hydrogel polymer immediately before being charged into the kneading chamber of the meat chopper was 70 ° C. From the obtained coarse crushed product, polymer particles were obtained by drying, pulverizing and classifying in the same manner as in Example 1.
  • Example 4 By the polymerization reaction in the mixture by the same operation as in Example 1, a lumpy hydrogel polymer was formed in the stainless steel vat. At 13 minutes after the completion of the dropping of the L-ascorbic acid aqueous solution, the temperature of the mixture showed the maximum value of 80 ° C. Within 30 seconds after the thermometer showed the maximum value, after confirming that the thermometer showed a temperature 0.1 ° C lower than the maximum value, the hydrogel polymer was taken out from the stainless steel vat and immediately about 6 cm. Cut to width. The cut water-containing gel polymer was placed in a polyethylene bag with a zipper (size inside the zipper: 280 mm ⁇ 200 mm, thickness 0.04 mm) so as not to contain air as much as possible.
  • a zipper size inside the zipper: 280 mm ⁇ 200 mm, thickness 0.04 mm
  • a polyethylene bag containing a hydrogel-like polymer was immersed in an ice bath at ⁇ 20 ° C. containing 78 parts by mass of ice and 22 parts by mass of NaCl. After allowing the hydrogel polymer to stand in an ice bath for 3 minutes, the hydrogel polymer was taken out from the polyethylene bag and coarsely crushed using a meat chopper by the same operation as in Example 1. The temperature of the ice bath was -10.8 ° C. when the hydrogel polymer was allowed to stand for 3 minutes. The time from when the temperature of the mixture in the polymerization reaction reached the maximum value to when the hydrogel-like polymer was started to be put into the kneading chamber of the meat chopper was 4 minutes.
  • the temperature of the hydrogel polymer immediately before being charged into the kneading chamber of the meat chopper was 49 ° C. From the obtained coarse crushed product, polymer particles were obtained by drying, pulverizing and classifying in the same manner as in Example 1.
  • the cut water-containing gel polymer was coarsely crushed using a meat chopper by the same operation as in Example 1.
  • the time from when the temperature of the mixture in the polymerization reaction reached the maximum value to when the hydrogel-like polymer was started to be put into the kneading chamber of the meat chopper was 30 minutes.
  • the temperature of the hydrogel polymer immediately before being charged into the kneading chamber of the meat chopper was 68 ° C. From the obtained coarse crushed product, polymer particles were obtained by drying, pulverizing and classifying in the same manner as in Example 1.
  • the cut water-containing gel polymer was placed in a polyethylene bag with a zipper (size inside the zipper: 280 mm ⁇ 200 mm, thickness 0.04 mm) so as not to contain air as much as possible.
  • a polyethylene bag containing a hydrogel-like polymer was immersed in an ice bath at ⁇ 20 ° C. containing 78 parts by mass of ice and 22 parts by mass of NaCl. After allowing the hydrogel polymer to stand in an ice bath for 3 minutes, the hydrogel polymer was taken out from the polyethylene bag and coarsely crushed using a meat chopper by the same operation as in Example 1. The temperature of the ice bath was -12.5 ° C. when the hydrogel polymer was allowed to stand for 3 minutes.
  • the time from when the temperature of the mixture in the polymerization reaction reached the maximum value to when the hydrogel-like polymer was started to be put into the kneading chamber of the meat chopper was 4 minutes.
  • the temperature of the hydrogel polymer immediately before being charged into the kneading chamber of the meat chopper was 68 ° C.
  • the time from when the temperature of the mixture in the polymerization reaction reached the maximum value to when the hydrogel-like polymer was started to be put into the kneading chamber of the meat chopper was 15 minutes.
  • the temperature of the hydrogel polymer immediately before being charged into the kneading chamber of the meat chopper was 68 ° C.
  • a 60 mm ⁇ 85 mm non-woven fabric bag was produced by pressure-bonding the non-woven fabrics to each other with heat seals on both sides extending in the longitudinal direction.
  • the width of the crimping portion was 5 mm.
  • a finely weighed 0.2 g of water-absorbent resin particles was contained in a non-woven fabric bag.
  • the non-woven fabric bag was closed by crimping the remaining one side extending in the lateral direction of the non-woven fabric bag with a heat seal.
  • a plurality of non-woven fabric bags were floated on 1000 g of physiological saline in a stainless steel vat (240 mm ⁇ 320 mm ⁇ 45 mm) so as not to overlap each other, whereby the entire non-woven fabric bag was completely moistened.
  • the non-woven fabric bag was immersed in the physiological saline solution using a spatula. After immersing the non-woven fabric bag in the physiological saline solution for 29 minutes, that is, 30 minutes after putting the non-woven fabric bag into the physiological saline solution, the non-woven fabric bag was taken out from the physiological saline solution.
  • Dissolved content The dissolved content of the polymer particles was measured in an environment of a temperature of 25 ° C. ⁇ 2 ° C. and a humidity of 50% ⁇ 10%.
  • 500 g of physiological saline in a 500 mL beaker was stirred with a stirrer (diameter 8 mm ⁇ length 30 mm columnar, without ring) rotating at 600 rpm.
  • the temperature of the saline solution was 25 ° C. 2.000 g of water-absorbent resin particles were put therein, and the dispersion liquid containing the polymer particles was stirred for 3 hours.
  • the dispersion was filtered through a 75 ⁇ m standard sieve and the filtrate was collected.

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  • Chemical & Material Sciences (AREA)
  • Health & Medical Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Medicinal Chemistry (AREA)
  • Polymers & Plastics (AREA)
  • Organic Chemistry (AREA)
  • Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)

Abstract

L'invention concerne un procédé de production d'une particule de résine absorbant l'eau, le procédé consistant à pulvériser grossièrement un polymère gélatineux contenant de l'eau formé à partir d'un mélange contenant un monomère et de l'eau de façon à former un produit grossièrement pulvérisé, puis à pulvériser grossièrement le produit grossièrement pulvérisé de façon à former un produit grossièrement pulvérisé contenant une pluralité de structures présentant des formes qui peuvent passer à travers des trous circulaires présentant des diamètres de 7 mm. Le temps écoulé t entre le moment auquel la température du mélange atteint une valeur maximale Tmax et le temps auquel la pulvérisation grossière démarre est de 15 minutes ou moins et le temps écoulé est une période de temps choisie de telle sorte que la quantité de particules polymères obtenues à partir du produit grossièrement pulvérisé qui se dissout dans une solution saline physiologique à 25 °C est inférieure à ladite quantité dans un cas où t est de 30 minutes et T vaut X. X est une température dans la plage de 70±3 °C. La température T du polymère gélatineux contenant de l'eau au moment où la pulvérisation grossière démarre se situe dans la plage X±25 °C.
PCT/JP2021/019823 2020-06-01 2021-05-25 Procédé de production de particule de résine absorbant d'eau Ceased WO2021246244A1 (fr)

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Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002121291A (ja) * 2000-02-29 2002-04-23 Nippon Shokubai Co Ltd 吸水性樹脂粉末およびその製造方法
JP2004067878A (ja) * 2002-08-06 2004-03-04 Toagosei Co Ltd 含水ゲル粒子の製造方法
JP2010202743A (ja) * 2009-03-02 2010-09-16 Nippon Shokubai Co Ltd 吸水性樹脂の製造方法
WO2012043821A1 (fr) * 2010-09-30 2012-04-05 株式会社日本触媒 Absorbant d'eau particulaire et méthode de fabrication de celui-ci
JP2018119142A (ja) * 2017-01-23 2018-08-02 住友精化株式会社 架橋重合体の製造方法および吸水性樹脂の製造方法
WO2019221235A1 (fr) * 2018-05-16 2019-11-21 株式会社日本触媒 Procédé de production d'une résine absorbant l'eau

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002121291A (ja) * 2000-02-29 2002-04-23 Nippon Shokubai Co Ltd 吸水性樹脂粉末およびその製造方法
JP2004067878A (ja) * 2002-08-06 2004-03-04 Toagosei Co Ltd 含水ゲル粒子の製造方法
JP2010202743A (ja) * 2009-03-02 2010-09-16 Nippon Shokubai Co Ltd 吸水性樹脂の製造方法
WO2012043821A1 (fr) * 2010-09-30 2012-04-05 株式会社日本触媒 Absorbant d'eau particulaire et méthode de fabrication de celui-ci
JP2018119142A (ja) * 2017-01-23 2018-08-02 住友精化株式会社 架橋重合体の製造方法および吸水性樹脂の製造方法
WO2019221235A1 (fr) * 2018-05-16 2019-11-21 株式会社日本触媒 Procédé de production d'une résine absorbant l'eau

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