WO2023136193A1 - Aqueous treatment agent for treating used or unused absorbent item, method for treating used or unused absorbent item using same - Google Patents

Aqueous treatment agent for treating used or unused absorbent item, method for treating used or unused absorbent item using same Download PDF

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Publication number
WO2023136193A1
WO2023136193A1 PCT/JP2023/000054 JP2023000054W WO2023136193A1 WO 2023136193 A1 WO2023136193 A1 WO 2023136193A1 JP 2023000054 W JP2023000054 W JP 2023000054W WO 2023136193 A1 WO2023136193 A1 WO 2023136193A1
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Prior art keywords
treatment agent
water
inorganic salt
based treatment
superabsorbent polymer
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PCT/JP2023/000054
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French (fr)
Japanese (ja)
Inventor
治 重枝
雅之 衣川
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共栄社化学株式会社
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Publication of WO2023136193A1 publication Critical patent/WO2023136193A1/en

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
    • B01J20/30—Processes for preparing, regenerating, or reactivating
    • B01J20/34—Regenerating or reactivating
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B09—DISPOSAL OF SOLID WASTE; RECLAMATION OF CONTAMINATED SOIL
    • B09B—DISPOSAL OF SOLID WASTE
    • B09B3/00—Destroying solid waste or transforming solid waste into something useful or harmless
    • B09B3/70—Chemical treatment, e.g. pH adjustment or oxidation
    • 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
    • B29B17/00—Recovery of plastics or other constituents of waste material containing plastics
    • B29B17/02—Separating plastics from other materials
    • 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
    • C08J11/00—Recovery or working-up of waste materials
    • C08J11/04—Recovery or working-up of waste materials of polymers
    • C08J11/06—Recovery or working-up of waste materials of polymers without chemical reactions
    • C08J11/08—Recovery or working-up of waste materials of polymers without chemical reactions using selective solvents for polymer components
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
    • Y02W30/00—Technologies for solid waste management
    • Y02W30/50—Reuse, recycling or recovery technologies
    • Y02W30/62—Plastics recycling; Rubber recycling

Definitions

  • the present invention relates to an aqueous treatment agent for treating used or unused absorbent articles and a method for treating used absorbent articles using the same.
  • Patent Document 1 A method for recovering constituent members of used absorbent articles has been proposed (Patent Document 1), which includes a separation step of separating the film and the absorbent agent material. Furthermore, Patent Document 1 describes that in the separation step, a step of inactivating the superabsorbent polymer with an inactivating agent such as an organic acid or a step of dissolving the hot-melt adhesive with a terpene may be provided. It is However, these methods cannot be said to be sufficiently efficient because the hot-melt adhesive is decomposed by physical impact before the process of dissolving it, and each process is separate.
  • Patent Document 3 a water-soluble paint remover containing benzyl alcohol, an alkaline component, a solubilizer, and the like is known as a remover used for removing paint.
  • a remover used for removing paint Patent Document 3
  • the use of such release agents for treating used absorbent articles as described above has not been known so far.
  • the present invention can easily disassemble each constituent member constituting the absorbent article, and the superabsorbent polymer can be inactivated. It is an object of the present invention to provide a water-based treatment agent capable of performing sterilization of used absorbent articles, and at the same time, capable of simplifying the process. Another object of the present invention is to provide a method for treating used absorbent articles, which can efficiently separate and recover used or unused absorbent articles for each constituent member. be.
  • the present invention comprises a polar solvent (A) having an SP value of 10 to 13, an inorganic alkali compound (B), an alkali metal inorganic salt or an alkaline earth metal inorganic salt (C), and an aromatic sulfonate (D). It is a water-based treatment agent for treating used or unused absorbent articles containing.
  • the polar solvent (A) is preferably at least one selected from the group consisting of benzyl alcohol, phenoxyethanol, and diethylene glycol monobutyl ether.
  • the inorganic alkaline compound (B) is preferably sodium hydroxide and/or potassium hydroxide.
  • the alkali metal inorganic salt or alkaline earth metal inorganic salt (C) is preferably at least one selected from the group consisting of sodium sulfate, sodium chloride, potassium chloride, and potassium sulfate.
  • the aromatic sulfonate (D) is preferably at least one selected from the group consisting of toluenesulfonate, xylenesulfonate, cumenesulfonate, and methoxybenzenesulfonate.
  • the present invention is a method for treating used or virgin absorbent articles comprising at least an absorbent body containing pulp and a superabsorbent polymer, a nonwoven fabric and a film as constituent members,
  • the absorbent article contains a polar solvent (A) having an SP value of 9 to 13, an inorganic alkali compound (B), an alkali metal inorganic salt or an alkaline earth metal inorganic salt (C), and an aromatic sulfonate (Ste (1) of applying an aqueous treatment agent containing D) to decompose the absorbent article into its constituent members and inactivate the superabsorbent polymer; Step (2) of separating and recovering each constituent member disassembled in step (1) It is also a method of treating used or virgin absorbent articles having
  • the water-based treatment agent for treating used or unused absorbent articles of the present invention can easily decompose the absorbent articles into individual constituent members, and at the same time inactivate the superabsorbent polymer. can be performed, thus allowing simplification of the process. At the same time, sterilization of absorbent articles can also be expected.
  • the absorbent article can be efficiently separated and collected for each constituent member.
  • FIG. 10 is an explanatory diagram showing the state and mass of absorbers (pulp and superabsorbent polymer (SAP)) of Examples 10 to 12 after a SAP inactivation test.
  • FIG. 10 is an explanatory diagram showing the state and mass of absorbers (pulp and superabsorbent polymer (SAP)) of Examples 13 to 16 after a SAP inactivation test.
  • FIG. 10 is an explanatory diagram showing the appearance and mass of absorbers (pulp and superabsorbent polymer (SAP)) of Comparative Examples 11 to 14 after an SAP inactivation test.
  • FIG. 10 is an explanatory diagram showing the state and mass of absorbers (pulp and superabsorbent polymer (SAP)) of Comparative Examples 15 to 17 after the SAP inactivation test.
  • FIG. 10 is an explanatory diagram showing the state and mass of absorbers (pulp and superabsorbent polymer (SAP)) of Comparative Examples 18 to 20 after a SAP inactivation test.
  • FIG. 10 is an explanatory diagram showing the appearance and mass of absorbers (pulp and superabsorbent polymer (SAP)) of Comparative Examples 21 to 23 after a SAP inactivation test.
  • FIG. 10 is an explanatory diagram showing the state and mass of absorbers (pulp and superabsorbent polymer (SAP)) of Comparative Examples 24 and 25 after the SAP inactivation test.
  • the aqueous treatment agent of the present invention comprises a polar solvent (A) having an SP value of 10 to 13, an inorganic alkali compound (B), an alkali metal inorganic salt or an alkaline earth metal inorganic salt (C), and an aromatic sulfonic acid. It contains salt (D) and is used in the process of separating and recovering used or unused absorbent articles for each constituent member when reusing (recycling) used absorbent articles. be.
  • A polar solvent having an SP value of 10 to 13
  • B inorganic alkali compound
  • C alkaline earth metal inorganic salt
  • D aromatic sulfonic acid
  • Absorbent articles handled in the present invention include, for example, disposable diapers, incontinence pads, sanitary napkins, bed sheets, pet sheets and the like.
  • a used absorbent article is an absorbent article that has been used by a user, and is usually an absorbent article that has absorbed the liquid excretion of the user.
  • used absorbent articles include those that have been used but have not absorbed excrement.
  • unused absorbent articles include those that have become defective in the factory manufacturing process.
  • the absorbent article include an absorbent body containing pulp and a superabsorbent polymer, a nonwoven fabric, and a film as at least structural members.
  • the absorbent article may include, as other constituent members, an adhesive tape, thread rubber made of urethane rubber, or the like.
  • Examples of the pulp contained in the absorber include cellulose fibers.
  • Cellulosic fibers include, for example, wood pulp, crosslinked pulp, non-wood pulp, regenerated cellulose, semi-synthetic cellulose, and the like.
  • Examples of the super absorbent polymer (SAP) contained in the absorber include water absorbing polymers such as polyacrylate, polysulfonate, and maleate anhydride. The superabsorbent polymer is usually particulate and dispersed in the pulp.
  • nonwoven fabric and film examples include olefin resins such as polyethylene and polypropylene, polyamide resins such as 6-nylon and 6,6-nylon, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), and the like. and polyester resins.
  • olefin resins such as polyethylene and polypropylene
  • polyamide resins such as 6-nylon and 6,6-nylon
  • PET polyethylene terephthalate
  • PBT polybutylene terephthalate
  • polyester resins polyester resins.
  • the above nonwoven fabric and film are liquid permeable nonwoven fabric, synthetic resin film having liquid permeable pores, composite sheets thereof, liquid impermeable nonwoven fabric, liquid impermeable synthetic resin film, these nonwoven fabrics. and a composite sheet or the like of a synthetic resin film is used.
  • a configuration example of the absorbent article includes, for example, one including a topsheet, a backsheet, and an absorbent body disposed between the topsheet and the backsheet.
  • the nonwoven fabric or film or the like is used for the top sheet and the back sheet.
  • one surface and the other surface of the absorbent body are respectively joined to the top sheet and the back sheet via an adhesive.
  • the portion (peripheral portion) of the topsheet that extends outside the absorber so as to surround the absorber is the portion of the backsheet that extends outside the absorber so as to surround the absorber. It is joined to the extended portion (peripheral portion) via an adhesive. Therefore, the absorbent body is wrapped inside the joined body of the top sheet and the back sheet.
  • Hot-melt adhesives include, for example, rubber-based adhesives such as styrene-ethylene-butadiene-styrene, styrene-butadiene-styrene, and styrene-isoprene-styrene, or olefin-based pressure-sensitive or heat-sensitive adhesives such as polyethylene. Examples include adhesives and the like.
  • a polar solvent (A) having a specific SP value an inorganic alkali compound (B), an alkali metal inorganic salt or an alkaline earth metal inorganic salt (C), and an aromatic sulfonate (D) are combined.
  • A polar solvent
  • B inorganic alkali compound
  • C alkali metal inorganic salt
  • D aromatic sulfonate
  • the water-based treatment agent of the present invention is preferably a treatment agent in which various components are homogenized. Uniformity is preferable in that the penetration into the absorbent article is improved and the adhesive, particularly the hot-melt adhesive, in the absorbent article can be sufficiently dissolved.
  • the adhesive is dissolved, the constituent members joined with the adhesive are separated from each other, and the constituent members such as the water absorber, the nonwoven fabric, and the film are decomposed. In this way, by dissolving the adhesive and decomposing each constituent member, it is possible to recycle the nonwoven fabric, the film, and the like.
  • the water-based treatment agent of the present invention also has the effect of inactivating the superabsorbent polymer in the absorbent body.
  • the action mechanism of the water-based treatment agent of the present invention for inactivating the superabsorbent polymer is not clear, it is presumed as follows.
  • the water-based treatment agent of the present invention Since the water-based treatment agent of the present invention has an affinity for water, it is incorporated into the superabsorbent polymer.
  • the water-based treatment agent incorporated into the superabsorbent polymer dissolves the water in the superabsorbent polymer. After dissolving a certain amount of water, the water-based treatment agent in the water-dissolved superabsorbent polymer becomes saturated and no longer dissolves water.
  • the polar solvent separates from water and is discharged from the superabsorbent polymer with a certain amount of water dissolved therein. As a result, the inorganic alkali metal salt and/or the inorganic alkaline earth metal salt remain in the superabsorbent polymer at a high concentration.
  • alkali metal ions or alkaline earth metal ions are present at a high concentration around the superabsorbent polymer. This creates an osmotic pressure between the solution and the superabsorbent polymer, causing dehydration. It is believed that such an action causes efficient dehydration and inactivation of the superabsorbent polymer.
  • the water-based treatment agent of the present invention causes dehydration of the superabsorbent polymer by the above action, there is no need to provide a separate process for inactivating the superabsorbent polymer, the process can be simplified, and the superabsorbent polymer can be It is preferable in that recovery is facilitated by volumetric compression from the time of water absorption due to inactivation of .
  • the polar solvent (A) should have an SP value of 10-13.
  • the SP value (solubility parameter ( ⁇ )) is a value defined by the regular solution theory introduced by Hildebrand, and is the square root of the heat of vaporization required to evaporate 1 cm 3 of liquid (cal/cm 3 ) 1 /2 .
  • the use of a polar solvent having an SP value within this range is preferable in terms of removal of the adhesive and inactivation of the superabsorbent polymer.
  • the SP value of the polar solvent used in the present invention is preferably 11 or more. On the other hand, the SP value is preferably 12.5 or less.
  • polar solvent (A) having the above SP value examples include benzyl alcohol (SP value: 12.1), phenethyl alcohol (SP value: 11.2), phenoxyethanol (SP value: 12.4), N -Methyl-2-pyrrolidone (NMP) (SP value: 11.2), diethylene glycol monobutyl ether (SP value: 10.2), isopropanol (SP value: 11.5), dimethylformamide (DMF) (SP value: 11 .9), dimethyl sulfoxide ((DMSO) SP value: 12.0), and the like. These may be used alone or in combination of two or more.
  • At least one selected from the group consisting of benzyl alcohol, phenoxyethanol, and diethylene glycol monobutyl ether is preferable.
  • benzyl alcohol and phenoxyethanol are more preferable from the viewpoints of removing the adhesive and inactivating the superabsorbent polymer.
  • phenoxyethanol which has a bactericidal effect, is used, a more bactericidal effect can be expected.
  • Examples of the inorganic alkaline compound (B) include sodium hydroxide, potassium hydroxide, sodium phosphate, potassium phosphate, sodium silicate, potassium silicate, etc. At least one selected from these may be used. preferable. Among them, sodium hydroxide and potassium hydroxide are more preferable from the standpoint of strong alkalinity.
  • alkali metal inorganic salt or alkaline earth metal inorganic salt (C) examples include sodium sulfate, sodium chloride, potassium sulfate, potassium chloride and the like, and it is preferable to use at least one selected from these.
  • Calcium chloride, aluminum chloride, aluminum sulfate, magnesium chloride, and magnesium sulfate which are shown in Patent Document 1, become hydroxides that are sparingly soluble in water under alkaline conditions. do not play a role.
  • the hydroxyl groups in the water-based treatment agent are consumed as hydroxides, the pH of the water-based treatment agent is lowered, and there is a possibility that the stripping performance is lowered.
  • urethane rubber when urethane rubber is used as thread rubber, it may not be possible to sufficiently disintegrate the urethane rubber.
  • sodium sulfate and potassium sulfate are more preferable from the viewpoint of inactivation efficiency of the superabsorbent polymer.
  • the aromatic sulfonate (D) used in the present invention is a component with which the polar solvent (A) and the like can be uniformly mixed.
  • each component and water can be uniformly mixed.
  • a water-based treatment agent in which each component is uniformly mixed it acts effectively on adhesives and the like.
  • the aromatic sulfonate (D) includes toluenesulfonate, xylenesulfonate, cumenesulfonate, methoxybenzenesulfonate and the like, and it is preferable to use at least one selected from these.
  • Examples of the toluenesulfonate, xylenesulfonate, cumenesulfonate, methoxybenzenesulfonate, and the like include salts of sodium, potassium, lithium, and calcium, with sodium salts being preferred.
  • sodium p-toluenesulfonate, sodium xylenesulfonate, sodium cumenesulfonate, and sodium methoxybenzenesulfonate play the role of a solubilizer as described above, and can be obtained by simply mixing the polar solvent and the like uniformly. It is preferable in that it can accelerate the deactivation of the superabsorbent polymer.
  • the water-based treatment agent of the present invention may contain, as a solubilizer, a glycol-based solvent such as propylene glycol, diethylene glycol, ethylene glycol, alkanolamine, or the like, as long as the performance is not impaired.
  • a glycol-based solvent such as propylene glycol, diethylene glycol, ethylene glycol, alkanolamine, or the like, as long as the performance is not impaired.
  • the content of the polar solvent (A) in the water-based treatment agent is preferably 20 to 90% by mass.
  • the lower limit of the content is more preferably 30% by mass, still more preferably 35% by mass, and most preferably 40% by mass.
  • the upper limit of the content is more preferably 60% by mass, still more preferably 50% by mass. If the polar solvent is too small, the ability to remove the adhesive tends to decrease. Solids such as salt (C) tend to precipitate.
  • the inorganic alkaline compound (B) is preferably contained in an amount of 1 to 10% by mass in the water-based treatment agent.
  • the content is more preferably 1 to 5% by mass, still more preferably 2 to 4.5% by mass. If the amount of the inorganic alkaline compound is too small, the ability to remove the adhesive may be lowered. On the other hand, if the inorganic alkaline compound is too small, it may not be possible to sufficiently disintegrate the urethane rubber when the urethane rubber is used as thread rubber.
  • the alkali metal inorganic salt or alkaline earth metal inorganic salt (C) is preferably contained in an aqueous treatment agent in an amount of 0.5 to 5% by mass.
  • the lower limit of the content is more preferably 1% by mass.
  • the upper limit of the content is more preferably 3% by mass, still more preferably 2% by mass. If the alkali metal inorganic salt or alkaline earth metal inorganic salt is too small, the deactivation efficiency of the superabsorbent polymer tends to decrease. Solids such as (C) tend to precipitate.
  • the aromatic sulfonate (D) is preferably contained in an aqueous treatment agent in an amount of 5 to 30% by mass.
  • the lower limit of the content is more preferably 12% by mass, still more preferably 15% by mass.
  • the upper limit of the content is more preferably 25% by mass, still more preferably 20% by mass. If the aromatic sulfonate is too small, the polar solvent will not be solubilized, and the superabsorbent polymer will not be sufficiently inactivated. On the contrary, if it is too large, the aromatic sulfonate (D), inorganic alkali compounds (B), alkali metal inorganic salts or alkaline earth metal inorganic salts (C) tend to precipitate.
  • the water-based treatment agent of the present invention preferably contains 10 to 50% by mass of water at the time of use.
  • a water-free treatment agent may be prepared and diluted with a predetermined amount of water just before use.
  • the present invention also includes a water-free water-based treatment agent.
  • the pH of the water-based treatment agent of the present invention is preferably 13.0 or higher.
  • the adhesive is excellent in removing ability.
  • urethane rubber is used as thread rubber, it can contribute to fully disintegrating urethane rubber. If the water-based treatment agent of the present invention is alkaline, it can be expected to have a bactericidal action.
  • the aqueous treatment agent of the present invention preferably contains a chelating agent. Containing a chelating agent works advantageously in preventing adhesion of water-derived metal scale such as calcium to treatment equipment.
  • an aminocarboxylic acid-based chelating agent is preferable, and specifically, nitrilotriacetic acid (NTA), ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA), hydroxyethylenediaminetriacetic acid (HEDTA), ethylenediamine. -N,N-disuccinic acid (EDDS) and the like.
  • NTA is preferable in terms of chelating power.
  • the chelating agent may be used alone or in combination of two or more. Also, the content of the chelating agent is preferably 0.1 to 1.0% by mass in the water-based treatment agent.
  • nonionic surfactants may be added to the aqueous detergent of the present invention.
  • anionic surfactants may be added to the aqueous detergent of the present invention.
  • amphoteric surfactants may be added to the aqueous detergent of the present invention.
  • the water-based treatment agent of the present invention may be prepared, for example, by mixing each of the above-mentioned raw materials and, if necessary, water by a conventional method such as stirring.
  • the method for treating used or unused absorbent articles of the present invention treats used or unused absorbent articles comprising at least an absorbent body containing pulp and a superabsorbent polymer, a nonwoven fabric, and a film as constituent members.
  • a method for The absorbent article contains a polar solvent (A) having an SP value of 10 to 13, an inorganic alkali compound (B), an alkali metal salt or alkaline earth metal salt (C), and an aromatic sulfonate (D).
  • the water-based treatment agent is applied to the absorbent article.
  • the method is not particularly limited, and may be performed as appropriate.
  • the absorbent article is immersed in the water-based treatment agent by placing the absorbent article in a container, tank, or the like containing the water-based treatment agent.
  • the immersion temperature is preferably 70 to 80°C. Within this temperature range, the adhesive can be removed without problems.
  • the immersion time is preferably 30 to 60 minutes.
  • the mixture may be stirred by rotating a propeller or the like.
  • the water-based treating agent dissolves the adhesive that joins the constituent members together, and the absorbent article is decomposed into constituent members such as absorbent bodies, nonwoven fabrics, and films.
  • the adhesive at the joint between the nonwoven fabric or film and other constituent members film, nonwoven fabric, absorber, etc.
  • the nonwoven fabric or film and other constituent members are not broken. It can be decomposed into each while maintaining the shape as it is without equalizing. Therefore, constituent members such as nonwoven fabrics and films of absorbent articles can be efficiently recovered.
  • the non-woven fabric or film can be reused as a highly pure resin, and the adhesive will not adversely affect the reuse of the non-woven fabric or film. can be suppressed.
  • the superabsorbent polymer is dehydrated by inactivation. Dehydration of the superabsorbent polymer greatly reduces the mass of the absorber, making separation and recovery easier. Moreover, since the superabsorbent polymer becomes less viscous by dehydration, the superabsorbent polymer adhering to the nonwoven fabric or film can be easily separated from them.
  • each disassembled component is separated and recovered.
  • the separation method is not particularly limited.
  • the constituent members are separated and recovered from the mixed liquid obtained in step (1) by utilizing the difference in buoyancy of the constituent members or by filtering using a nonwoven fabric, a sieve, or the like.
  • the pulp and the superabsorbent polymer are not separated, but separated and recovered as an integrated absorbent.
  • washing with water may be performed before or during the separation, or after recovery.
  • the recovered nonwoven fabric, film, etc. may be dehydrated and dried by heating, that is, dried in an atmosphere at a temperature higher than room temperature or in hot air, if necessary.
  • step (2) neutralization may be performed using water containing organic acids such as citric acid, malic acid, succinic acid, and fumaric acid.
  • organic acids such as citric acid, malic acid, succinic acid, and fumaric acid.
  • a step of washing the used or unused absorbent article with water containing a detergent or the like may be provided in advance, or the method may also serve as the washing step. There may be.
  • the nonwoven fabrics and films recovered as described above are suitable for recycling because they do not have an adhesive attached thereto.
  • the pulp and the superabsorbent polymer in the recovered absorbent body may be appropriately separated and recovered by a known method.
  • the recovered pulp and superabsorbent polymer can each be reused.
  • used or unused absorbent articles can be processed in a single step without degrading the absorbent article by physical impact prior to the step of dissolving the hot-melt adhesive. can be disassembled for each constituent member, efficient separation and collection of the constituent members is possible.
  • water-based treatment agent of the present invention can be recovered after use in the treatment method described above, subjected to treatment such as concentration as necessary, and reused multiple times.
  • Example 1 50% diethylene glycol monobutyl ether, 15% sodium p-toluenesulfonate, 4.3% sodium hydroxide, 0.35% NTA, 1% sodium sulfate and 33% water were mixed to prepare an aqueous treatment agent.
  • evaluation was made by the following hot-melt adhesive removal test and superabsorbent polymer deactivation test.
  • solubilization state of the resulting water-based treatment agent was also evaluated. Those results are shown in Table 1.
  • ⁇ Hot melt adhesive removal test> A commercially available paper diaper (Merries (registered trademark) manufactured by Kao Corporation) was cut into 5 cm ⁇ 5 cm pieces and immersed in 50 g of a water-based treatment agent at a temperature of 80° C. for 30 minutes, followed by the following evaluations.
  • ⁇ The constituent members of the paper diaper were disassembled, but there was much stickiness on the surfaces of the constituent members.
  • x The constituent members of the disposable diaper were not disassembled.
  • the mass of SAP + pulp after filtration is 25 g or less ⁇ : The mass of SAP + pulp after filtration is 26 to 30 g ⁇ : The mass of SAP + pulp after filtration is 31 to 35 g ⁇ : The mass of SAP + pulp after filtration is 36 g or more
  • Example 2 Each test was conducted in the same manner as in Example 1, except that the composition of the water-based treatment agent was as shown in Table 1. The results are shown in Table 1.
  • Example 10-16 A water-based treatment agent was prepared in the same manner as in Example 1, except that the alkali metal salts and alkaline earth metal salts shown in Table 3 were used, and an inactivation test of SAP was performed by the following method. The results are shown in Table 3, FIGS. 1 and 2.
  • a urethane rubber disintegration test was carried out by the following method.
  • ⁇ Urethane rubber disintegration test> (1) A commercially available paper diaper (Merries (registered trademark) manufactured by Kao Corporation) was cut into pieces of about 5 ⁇ 5 cm, and the portion containing rubber thread (urethane rubber) was immersed in 50 g of a water-based treatment agent. (2) While heating to 80°C, the state of the thread rubber was visually observed and evaluated as follows. O: Collapsed into tatters within 3 hours, and the prototype could not be confirmed. ⁇ : Slight changes such as swelling occurred within 6 hours, but the original shape was confirmed. x: There was no change in shape even after 6 hours or more. The results are shown in Table 3.
  • Examples 17-19 A water-based treatment agent was prepared in the same manner as in Example 1, except that the composition of the water-based treatment agent was changed as shown in Table 5. Using the water-based treatment agent thus obtained, the SAP deactivation (dehydration performance) test, the hot-melt adhesive removal test, and the urethane rubber disintegration test were carried out. The results are shown in Table 5.
  • the aqueous treatment agent of the present invention is suitable for separating and recovering absorbent articles such as used or unused disposable diapers.

Abstract

The present invention provides an aqueous treatment agent for separation/recovery of a used or unused absorbent item such as a disposable diaper, the treatment agent making it possible to easily separate constituting members of an absorbent item individually and at the same time, to inactivate the highly absorbent polymer and sterilize the absorbent item, thereby simplifying the process. The aqueous treatment agent for treating a used or unused absorbent item contains: a polar solvent (A) having an SP value of 10 to 13; an inorganic alkali compound (B); an alkali metal inorganic salt or an alkaline earth metal inorganic salt (C); and an aromatic sulfonate (D).

Description

使用済みもしくは未使用吸収性物品を処理するための水系処理剤及びそれを用いた使用済みもしくは未使用吸収性物品を処理する方法Aqueous treatment agent for treating used or unused absorbent articles and method for treating used or unused absorbent articles using the same
本発明は、使用済みもしくは未使用吸収性物品を処理するための水系処理剤及びそれを用いた使用済み吸収性物品を処理する方法に関するものである。 TECHNICAL FIELD The present invention relates to an aqueous treatment agent for treating used or unused absorbent articles and a method for treating used absorbent articles using the same.
近年、使用済みの使い捨て紙おむつ等の吸収性物品を再資源化する試みがなされている。使用済み吸収性物品を再資源化するためには、通常、使用済み吸収性物品を水中で分解し、吸収性物品の構成部材毎に分離し、回収することが行われる。 In recent years, attempts have been made to recycle absorbent articles such as used disposable diapers. In order to recycle used absorbent articles, it is common practice to decompose used absorbent articles in water, separate the constituent members of the absorbent article, and collect them.
上記方法として、使用済み吸収性物品を水で膨潤させる前処理工程と、膨潤した前記使用済み吸収性物品に物理的な衝撃を与えて、フィルムと吸収体材料とを分解する分解工程と、分解されたフィルムと吸収体剤材料とを分離する分離工程とを備える、使用済み吸収性物品の構成部材を回収する方法が提案されている（特許文献１）。更に、特許文献１には、上記分離工程において、有機酸等の不活化剤により高吸水性ポリマーを不活化する工程や、テルペンによりホットメルト接着剤を溶解させる工程を設けてもよいことが記載されている。しかしながら、これらの方法は、ホットメルト接着剤を溶解させる工程の前に物理的な衝撃で分解を行ったり、各工程が別々であったりして、充分効率的とはいえない。 The above method includes a pretreatment step of swelling the used absorbent article with water, a decomposition step of applying a physical impact to the swollen used absorbent article to decompose the film and the absorbent material, and A method for recovering constituent members of used absorbent articles has been proposed (Patent Document 1), which includes a separation step of separating the film and the absorbent agent material. Furthermore, Patent Document 1 describes that in the separation step, a step of inactivating the superabsorbent polymer with an inactivating agent such as an organic acid or a step of dissolving the hot-melt adhesive with a terpene may be provided. It is However, these methods cannot be said to be sufficiently efficient because the hot-melt adhesive is decomposed by physical impact before the process of dissolving it, and each process is separate.
また、使用済み吸収性物品を酸性電解液で処理する方法が提案されており、その際に、アルカリ金属塩、アルカリ土類金属塩及び遷移金属塩等を用いて、高吸水性ポリマーを不活化させる方法が提案されている（特許文献２）。しかしながら、実施例で使用されているのは、酸化カルシウムのみであり、その他の不活化剤については検証がなされていない。 In addition, a method of treating used absorbent articles with an acidic electrolyte has been proposed, in which alkali metal salts, alkaline earth metal salts, transition metal salts, etc. are used to deactivate superabsorbent polymers. A method has been proposed (Patent Document 2). However, only calcium oxide is used in the examples, and other inactivating agents have not been verified.
一方、塗料を剥離する際に用いられる剥離剤として、ベンジルアルコール、アルカリ成分及び可溶化剤等を含む水溶性塗料剥離剤が知られている（特許文献３）。しかしながら、このような剥離剤を、上記のような使用済み吸収性物品の処理に使用することはこれまで知られていない。 On the other hand, a water-soluble paint remover containing benzyl alcohol, an alkaline component, a solubilizer, and the like is known as a remover used for removing paint (Patent Document 3). However, the use of such release agents for treating used absorbent articles as described above has not been known so far.
特開２０１８－１７１５８９号公報JP 2018-171589 A 特開２０１４－７９６６６号公報JP 2014-79666 A 特開２００４－２５０５７３号公報Japanese Patent Application Laid-Open No. 2004-250573
本発明は、使用済みもしくは未使用の使い捨て紙おむつ等の吸収性物品を分離・回収するにあたり、吸収性物品を構成する構成部材毎に容易に分解することができ、高吸水性ポリマーの不活化も行うことができ、同時に、使用済み吸収性物品の殺菌も期待できる、工程の簡略化を可能とする水系処理剤を提供することを目的とするものである。
また、本発明は、使用済みもしくは未使用吸収性物品を、構成部材毎に、効率的に分離し、回収することができる使用済吸収性物品の処理方法を提供することを目的とするものである。 INDUSTRIAL APPLICABILITY In separating and recovering absorbent articles such as used or unused disposable diapers, the present invention can easily disassemble each constituent member constituting the absorbent article, and the superabsorbent polymer can be inactivated. It is an object of the present invention to provide a water-based treatment agent capable of performing sterilization of used absorbent articles, and at the same time, capable of simplifying the process.
Another object of the present invention is to provide a method for treating used absorbent articles, which can efficiently separate and recover used or unused absorbent articles for each constituent member. be.
本発明は、ＳＰ値が１０～１３である極性溶媒（Ａ）、無機系アルカリ化合物（Ｂ）、アルカリ金属無機塩又はアルカリ土類金属無機塩（Ｃ）及び芳香族スルホン酸塩（Ｄ）を含有する、使用済みもしくは未使用吸収性物品を処理するための水系処理剤である。 The present invention comprises a polar solvent (A) having an SP value of 10 to 13, an inorganic alkali compound (B), an alkali metal inorganic salt or an alkaline earth metal inorganic salt (C), and an aromatic sulfonate (D). It is a water-based treatment agent for treating used or unused absorbent articles containing.
上記極性溶媒（Ａ）が、ベンジルアルコール、フェノキシエタノール、及びジエチレングリコールモノブチルエーテルからなる群から選択される少なくとも１つであることが好ましい。
上記無機系アルカリ化合物（Ｂ）が、水酸化ナトリウム及び／又は水酸化カリウムであることが好ましい。 The polar solvent (A) is preferably at least one selected from the group consisting of benzyl alcohol, phenoxyethanol, and diethylene glycol monobutyl ether.
The inorganic alkaline compound (B) is preferably sodium hydroxide and/or potassium hydroxide.
上記アルカリ金属無機塩又はアルカリ土類金属無機塩（Ｃ）が、硫酸ナトリウム、塩化ナトリウム、塩化カリウム、及び硫酸カリウムからなる群から選択される少なくとも１つであることが好ましい。
上記芳香族スルホン酸塩（Ｄ）が、トルエンスルホン酸塩、キシレンスルホン酸塩、キュメンスルホン酸塩、及びメトキシベンゼンスルホン酸塩からなる群から選択される少なくとも１種であることが好ましい。 The alkali metal inorganic salt or alkaline earth metal inorganic salt (C) is preferably at least one selected from the group consisting of sodium sulfate, sodium chloride, potassium chloride, and potassium sulfate.
The aromatic sulfonate (D) is preferably at least one selected from the group consisting of toluenesulfonate, xylenesulfonate, cumenesulfonate, and methoxybenzenesulfonate.
本発明は、パルプ及び高吸水性ポリマーを含む吸収体、不織布並びにフィルムを、少なくとも構成部材として備える使用済みもしくは未使用吸収性物品を処理する方法であって、
上記吸収性物品に、ＳＰ値が９～１３である極性溶媒（Ａ）、無機系アルカリ化合物（Ｂ）、アルカリ金属無機塩又はアルカリ土類金属無機塩（Ｃ）、及び芳香族スルホン酸塩（Ｄ）を含有する水系処理剤を付与して、上記吸収性物品を上記構成部材毎に分解すると共に、上記高吸水性ポリマーを不活化する工程（１）、
工程（１）で分解された各構成部材を分離し、回収する工程（２）
を有する使用済みもしくは未使用吸収性物品を処理する方法でもある。 The present invention is a method for treating used or virgin absorbent articles comprising at least an absorbent body containing pulp and a superabsorbent polymer, a nonwoven fabric and a film as constituent members,
The absorbent article contains a polar solvent (A) having an SP value of 9 to 13, an inorganic alkali compound (B), an alkali metal inorganic salt or an alkaline earth metal inorganic salt (C), and an aromatic sulfonate ( Step (1) of applying an aqueous treatment agent containing D) to decompose the absorbent article into its constituent members and inactivate the superabsorbent polymer;
Step (2) of separating and recovering each constituent member disassembled in step (1)
It is also a method of treating used or virgin absorbent articles having
本発明の使用済みもしくは未使用吸収性物品を処理するための水系処理剤は、吸収性物品を、構成する構成部材毎に容易に分解することができ、同時に、高吸水性ポリマーの不活化も行うことができるものであり、よって、工程の簡略化を可能とする。また、同時に、吸収性物品の殺菌も期待できる。
また、本発明の使用済みもしくは未使用吸収性物品の処理方法により、吸収性物品を、構成部材毎に、効率的に分離し、回収することができる。 The water-based treatment agent for treating used or unused absorbent articles of the present invention can easily decompose the absorbent articles into individual constituent members, and at the same time inactivate the superabsorbent polymer. can be performed, thus allowing simplification of the process. At the same time, sterilization of absorbent articles can also be expected.
In addition, according to the used or unused absorbent article processing method of the present invention, the absorbent article can be efficiently separated and collected for each constituent member.
実施例１０～１２の吸収体（パルプと高吸水性ポリマー（ＳＡＰ））の、ＳＡＰの不活化試験後の様子と質量を示す説明図である。FIG. 10 is an explanatory diagram showing the state and mass of absorbers (pulp and superabsorbent polymer (SAP)) of Examples 10 to 12 after a SAP inactivation test. 実施例１３～１６の吸収体（パルプと高吸水性ポリマー（ＳＡＰ））の、ＳＡＰの不活化試験後の様子と質量を示す説明図である。FIG. 10 is an explanatory diagram showing the state and mass of absorbers (pulp and superabsorbent polymer (SAP)) of Examples 13 to 16 after a SAP inactivation test. 比較例１１～１４の吸収体（パルプと高吸水性ポリマー（ＳＡＰ））の、ＳＡＰの不活化試験後の様子と質量を示す説明図である。FIG. 10 is an explanatory diagram showing the appearance and mass of absorbers (pulp and superabsorbent polymer (SAP)) of Comparative Examples 11 to 14 after an SAP inactivation test. 比較例１５～１７の吸収体（パルプと高吸水性ポリマー（ＳＡＰ））の、ＳＡＰの不活化試験後の様子と質量を示す説明図である。FIG. 10 is an explanatory diagram showing the state and mass of absorbers (pulp and superabsorbent polymer (SAP)) of Comparative Examples 15 to 17 after the SAP inactivation test. 比較例１８～２０の吸収体（パルプと高吸水性ポリマー（ＳＡＰ））の、ＳＡＰの不活化試験後の様子と質量を示す説明図である。FIG. 10 is an explanatory diagram showing the state and mass of absorbers (pulp and superabsorbent polymer (SAP)) of Comparative Examples 18 to 20 after a SAP inactivation test. 比較例２１～２３の吸収体（パルプと高吸水性ポリマー（ＳＡＰ））の、ＳＡＰの不活化試験後の様子と質量を示す説明図である。FIG. 10 is an explanatory diagram showing the appearance and mass of absorbers (pulp and superabsorbent polymer (SAP)) of Comparative Examples 21 to 23 after a SAP inactivation test. 比較例２４～２５の吸収体（パルプと高吸水性ポリマー（ＳＡＰ））の、ＳＡＰの不活化試験後の様子と質量を示す説明図である。FIG. 10 is an explanatory diagram showing the state and mass of absorbers (pulp and superabsorbent polymer (SAP)) of Comparative Examples 24 and 25 after the SAP inactivation test.
以下、本発明を詳細に説明する。
本発明の水系処理剤は、ＳＰ値が１０～１３である極性溶媒（Ａ）、無機系アルカリ化合物（Ｂ）、アルカリ金属無機塩又はアルカリ土類金属無機塩（Ｃ）、及び芳香族スルホン酸塩（Ｄ）を含有するものであり、使用済み吸収性物品を再利用（リサイクル）するにあたり、使用済みもしくは未使用吸収性物品を構成部材毎に分離・回収するための処理において使用するものである。 The present invention will be described in detail below.
The aqueous treatment agent of the present invention comprises a polar solvent (A) having an SP value of 10 to 13, an inorganic alkali compound (B), an alkali metal inorganic salt or an alkaline earth metal inorganic salt (C), and an aromatic sulfonic acid. It contains salt (D) and is used in the process of separating and recovering used or unused absorbent articles for each constituent member when reusing (recycling) used absorbent articles. be.
本発明で取り扱う吸収性物品としては、例えば、紙おむつ、尿取りパッド、生理用ナプキン、ベッドシーツ、ペットシーツ等が挙げられる。
また、使用済み吸収性物品とは、使用者によって使用された吸収性物品であり、通常、使用者の液体の排泄物を吸収した状態の吸収性物品である。ただし、本実施の形態では、使用済み吸収性物品は、使用されたが排泄物を吸収していないものを含む。また、未使用吸収性物品は、工場の製造過程において不良品となったもの等を含む。 Absorbent articles handled in the present invention include, for example, disposable diapers, incontinence pads, sanitary napkins, bed sheets, pet sheets and the like.
A used absorbent article is an absorbent article that has been used by a user, and is usually an absorbent article that has absorbed the liquid excretion of the user. However, in the present embodiment, used absorbent articles include those that have been used but have not absorbed excrement. In addition, unused absorbent articles include those that have become defective in the factory manufacturing process.
上記吸収性物品は、具体的には例えば、パルプ及び高吸水性ポリマーを含む吸収体、不織布並びにフィルムを、少なくとも構成部材として備えるものを例示することができる。上記吸収性物品は、その他の構成部材として、粘着テープ、ウレタンゴム等からなる糸ゴム等を備えるものであってもよい。 Specific examples of the absorbent article include an absorbent body containing pulp and a superabsorbent polymer, a nonwoven fabric, and a film as at least structural members. The absorbent article may include, as other constituent members, an adhesive tape, thread rubber made of urethane rubber, or the like.
上記吸収体に含まれるパルプとしては、例えば、セルロース系繊維が挙げられる。セルロース系繊維としては、例えば、木材パルプ、架橋パルプ、非木材パルプ、再生セルロース、半合成セルロース等が挙げられる。
また、上記吸収体に含まれる高吸収性ポリマー（ＳｕｐｅｒＡｂｓｏｒｂｅｎｔ　Ｐｏｌｙｍｅｒ：ＳＡＰ）としては、例えば、ポリアクリル酸塩系、ポリスルホン酸塩系、無水マレイン酸塩系等の吸水性ポリマーが挙げられる。上記高吸収性ポリマーは、通常、粒子状で、パルプ中に分散している。 Examples of the pulp contained in the absorber include cellulose fibers. Cellulosic fibers include, for example, wood pulp, crosslinked pulp, non-wood pulp, regenerated cellulose, semi-synthetic cellulose, and the like.
Examples of the super absorbent polymer (SAP) contained in the absorber include water absorbing polymers such as polyacrylate, polysulfonate, and maleate anhydride. The superabsorbent polymer is usually particulate and dispersed in the pulp.
上記不織布やフィルムの材料としては、例えば、ポリエチレン、ポリプロピレン等のオレフィン系樹脂、６－ナイロン、６，６－ナイロン等のポリアミド系樹脂、ポリエチレンタレフタレート（ＰＥＴ）、ポリブチレンテレタレート（ＰＢＴ）等のポリエステル系樹脂等が挙げられる。 Examples of materials for the nonwoven fabric and film include olefin resins such as polyethylene and polypropylene, polyamide resins such as 6-nylon and 6,6-nylon, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), and the like. and polyester resins.
上記不織布及びフィルムは、目的に応じて、液透過性の不織布、液透過孔を有する合成樹脂フィルム、これらの複合シート、または液不透過性の不織布、液不透過性の合成樹脂フィルム、これら不織布と合成樹脂フィルムとの複合シート等が使用される。 Depending on the purpose, the above nonwoven fabric and film are liquid permeable nonwoven fabric, synthetic resin film having liquid permeable pores, composite sheets thereof, liquid impermeable nonwoven fabric, liquid impermeable synthetic resin film, these nonwoven fabrics. and a composite sheet or the like of a synthetic resin film is used.
上記吸収性物品の構成例として、例えば、表面シートと、裏面シートと、表面シートと裏面シートとの間に配置された吸収体とを備えるものが挙げられる。上記表面シート及び裏面シートには、上記不織布又はフィルム等が使用される。 A configuration example of the absorbent article includes, for example, one including a topsheet, a backsheet, and an absorbent body disposed between the topsheet and the backsheet. The nonwoven fabric or film or the like is used for the top sheet and the back sheet.
上記構成例において、例えば、吸収体の一方の面及び他方の面は、それぞれ表面シート及び裏面シートに接着剤を介して接合されている。平面視で、表面シートのうちの、吸収体を囲むように、吸収体の外側に延出した部分（周縁部分）は、裏面シートのうちの、吸収体を囲むように、吸収体の外側に延出した部分（周縁部分）と接着剤を介して接合されている。したがって、吸収体は表面シートと裏面シートとの接合体の内部に包み込まれている。 In the above configuration example, for example, one surface and the other surface of the absorbent body are respectively joined to the top sheet and the back sheet via an adhesive. In a plan view, the portion (peripheral portion) of the topsheet that extends outside the absorber so as to surround the absorber is the portion of the backsheet that extends outside the absorber so as to surround the absorber. It is joined to the extended portion (peripheral portion) via an adhesive. Therefore, the absorbent body is wrapped inside the joined body of the top sheet and the back sheet.
上記接着剤としては、例えば、ホットメルト型接着剤等が挙げられる。ホットメルト型接着剤としては、例えば、スチレン－エチレン－ブタジエン－スチレン、スチレン－ブタジエン－スチレン、スチレン－イソプレン－スチレン等のゴム系主体、又はポリエチレン等のオレフィン系主体の感圧型接着剤又は感熱型接着剤などが挙げられる。 Examples of the adhesives include hot-melt adhesives. Hot-melt adhesives include, for example, rubber-based adhesives such as styrene-ethylene-butadiene-styrene, styrene-butadiene-styrene, and styrene-isoprene-styrene, or olefin-based pressure-sensitive or heat-sensitive adhesives such as polyethylene. Examples include adhesives and the like.
本発明においては、特定ＳＰ値の極性溶媒（Ａ）、無機系アルカリ化合物（Ｂ）、アルカリ金属無機塩又はアルカリ土類金属無機塩（Ｃ）、及び芳香族スルホン酸塩（Ｄ）を組み合わせて水系処理剤とすることで、上記のような使用済み吸収性物品を、各構成部材に分解できるとともに、高吸水性ポリマーの不活化や吸収性物品の殺菌も可能としたものである。 In the present invention, a polar solvent (A) having a specific SP value, an inorganic alkali compound (B), an alkali metal inorganic salt or an alkaline earth metal inorganic salt (C), and an aromatic sulfonate (D) are combined. By using a water-based treatment agent, it is possible to decompose the used absorbent article as described above into its constituent members, and it is possible to deactivate the superabsorbent polymer and sterilize the absorbent article.
本発明の水系処理剤は、各種成分が均一化した状態の処理剤であることが好ましい。均一化することによって、吸収性物品内への浸透性が良好となり、吸収性物品中の接着剤、特に、ホットメルト接着剤を充分に溶解することができる点で好ましい。接着剤で接合している各構成部材が、接着剤が溶解することにより、個々に離れ、吸水体、不織布、フィルム等の構成部材毎に分解する。このように、接着剤を溶解して構成部材毎に分解することで、不織布やフィルム等の再資源化が可能となる。 The water-based treatment agent of the present invention is preferably a treatment agent in which various components are homogenized. Uniformity is preferable in that the penetration into the absorbent article is improved and the adhesive, particularly the hot-melt adhesive, in the absorbent article can be sufficiently dissolved. When the adhesive is dissolved, the constituent members joined with the adhesive are separated from each other, and the constituent members such as the water absorber, the nonwoven fabric, and the film are decomposed. In this way, by dissolving the adhesive and decomposing each constituent member, it is possible to recycle the nonwoven fabric, the film, and the like.
本発明の水系処理剤は、吸収体中の高吸水性ポリマーを不活化させるという作用も有する。本発明の水系処理剤の高吸水性ポリマーの不活化の作用機序は、明らかではないが、以下のように推察される。 The water-based treatment agent of the present invention also has the effect of inactivating the superabsorbent polymer in the absorbent body. Although the action mechanism of the water-based treatment agent of the present invention for inactivating the superabsorbent polymer is not clear, it is presumed as follows.
本発明の水系処理剤は、水との親和力があるために、高吸水性ポリマー内に取り込まれる。高吸水性ポリマー内に取り込まれた水系処理剤は、高吸水性ポリマー内の水を溶解する。水を溶解した高吸水性ポリマー内の水系処理剤は、一定量の水を溶解した後、飽和状態となり、水を溶解しなくなる。水を溶解しなくなった水系処理剤は、極性溶媒が水と分離し、一定量の水を溶解したまま高吸水性ポリマー内から吐き出される。
これによって、無機アルカリ金属塩及び／又は無機アルカリ土類金属塩は、高濃度で高吸水性ポリマー中に残存することになる。すなわち、高吸水性ポリマーの周りに、高濃度でアルカリ金属イオン又はアルカリ土類金属イオンが存在することとなる。これによって、溶液と高吸水性ポリマーとの間で浸透圧が発生し脱水が起こる。このような作用によって、効率的な脱水が起こり、高吸水性ポリマーの不活化がなされると考えられる。 Since the water-based treatment agent of the present invention has an affinity for water, it is incorporated into the superabsorbent polymer. The water-based treatment agent incorporated into the superabsorbent polymer dissolves the water in the superabsorbent polymer. After dissolving a certain amount of water, the water-based treatment agent in the water-dissolved superabsorbent polymer becomes saturated and no longer dissolves water. In the water-based treatment agent that no longer dissolves water, the polar solvent separates from water and is discharged from the superabsorbent polymer with a certain amount of water dissolved therein.
As a result, the inorganic alkali metal salt and/or the inorganic alkaline earth metal salt remain in the superabsorbent polymer at a high concentration. That is, alkali metal ions or alkaline earth metal ions are present at a high concentration around the superabsorbent polymer. This creates an osmotic pressure between the solution and the superabsorbent polymer, causing dehydration. It is believed that such an action causes efficient dehydration and inactivation of the superabsorbent polymer.
本発明の水系処理剤は、上記作用によって高吸水性ポリマーの脱水を生じさせることから、別途、高吸水性ポリマーの不活化工程を設ける必要がなく、工程を簡略化でき、及び高吸水性ポリマーの不活化による吸水時からの体積圧縮によって回収を容易にするという点で好ましいものである。 Since the water-based treatment agent of the present invention causes dehydration of the superabsorbent polymer by the above action, there is no need to provide a separate process for inactivating the superabsorbent polymer, the process can be simplified, and the superabsorbent polymer can be It is preferable in that recovery is facilitated by volumetric compression from the time of water absorption due to inactivation of .
上記極性溶媒（Ａ）は、ＳＰ値が１０～１３であることが必要である。
ＳＰ値（溶解パラメーター（δ））は、ヒルデブラントによって導入された正則溶液論により定義された値であり、１ｃｍ３の液体が蒸発するために必要な蒸発熱の平方根（ｃａｌ／ｃｍ３）１／２から計算されるものである。
本発明において、ＳＰ値がこの範囲である極性溶媒を使用することで、接着剤の除去、高吸水性ポリマーの不活化という点で好ましい。
また、本発明において用いる極性溶媒のＳＰ値は、１１以上であることが好ましい。一方、ＳＰ値は、１２．５以下であることが好ましい。 The polar solvent (A) should have an SP value of 10-13.
The SP value (solubility parameter (δ)) is a value defined by the regular solution theory introduced by Hildebrand, and is the square root of the heat of vaporization required to evaporate 1 cm 3 of liquid (cal/cm 3 ) 1 /2 .
In the present invention, the use of a polar solvent having an SP value within this range is preferable in terms of removal of the adhesive and inactivation of the superabsorbent polymer.
Moreover, the SP value of the polar solvent used in the present invention is preferably 11 or more. On the other hand, the SP value is preferably 12.5 or less.
上記ＳＰ値を有する極性溶媒（Ａ）として、具体的には、ベンジルアルコール（ＳＰ値：１２．１）、フェネチルアルコール（ＳＰ値：１１．２）、フェノキシエタノール（ＳＰ値：１２．４）、Ｎ－メチル－２－ピロリドン（ＮＭＰ）（ＳＰ値：１１．２）、ジエチレングリコールモノブチルエーテル（ＳＰ値：１０．２）、イソプロパノール（ＳＰ値：１１．５）、ジメチルホルムアミド（ＤＭＦ）（ＳＰ値：１１．９）、ジメチルスルホキシド（（ＤＭＳＯ）ＳＰ値：１２．０）等が挙げられる。これらは、単独でも、２種以上を併用してもよい。中でも、ベンジルアルコール、フェノキシエタノール、及びジエチレングリコールモノブチルエーテルからなる群から選択される少なくとも１つであることが好ましい。特に、ベンジルアルコール、フェノキシエタノールが接着剤の除去、高吸水性ポリマーの不活化の点などからより好ましい。
また、殺菌効果のあるフェノキシエタノールを使用すると、より殺菌効果が期待できる。 Specific examples of the polar solvent (A) having the above SP value include benzyl alcohol (SP value: 12.1), phenethyl alcohol (SP value: 11.2), phenoxyethanol (SP value: 12.4), N -Methyl-2-pyrrolidone (NMP) (SP value: 11.2), diethylene glycol monobutyl ether (SP value: 10.2), isopropanol (SP value: 11.5), dimethylformamide (DMF) (SP value: 11 .9), dimethyl sulfoxide ((DMSO) SP value: 12.0), and the like. These may be used alone or in combination of two or more. Among them, at least one selected from the group consisting of benzyl alcohol, phenoxyethanol, and diethylene glycol monobutyl ether is preferable. In particular, benzyl alcohol and phenoxyethanol are more preferable from the viewpoints of removing the adhesive and inactivating the superabsorbent polymer.
Further, if phenoxyethanol, which has a bactericidal effect, is used, a more bactericidal effect can be expected.
上記無機系アルカリ化合物（Ｂ）は、水酸化ナトリウム、水酸化カリウム、リン酸ナトリウム、リン酸カリウム、ケイ酸ナトリウム、ケイ酸カリウム等が挙げられ、これらから選択される少なくとも１種を用いることが好ましい。
中でも、水酸化ナトリウム及び水酸化カリウムが、アルカリ性の強さの点からより好ましい。 Examples of the inorganic alkaline compound (B) include sodium hydroxide, potassium hydroxide, sodium phosphate, potassium phosphate, sodium silicate, potassium silicate, etc. At least one selected from these may be used. preferable.
Among them, sodium hydroxide and potassium hydroxide are more preferable from the standpoint of strong alkalinity.
上記アルカリ金属無機塩又はアルカリ土類金属無機塩（Ｃ）は、硫酸ナトリウム、塩化ナトリウム、硫酸カリウム、塩化カリウム等が挙げられ、これらから選択される少なくとも１種を用いることが好ましい。特許文献１に示される、塩化カルシウム、塩化アルミニウム、硫酸アルミニウム、塩化マグネシウム、硫酸マグネシウムは、アルカリ条件下では水に難溶な水酸化物となるために、高吸水性ポリマーの不活化剤としての役割を果たさない。また、水酸化物となり水系処理剤中の水酸基が消費されるために水系処理剤のｐHが低下し、剥離性能が低下するおそれがある。また、ウレタンゴムを糸ゴムとして使用している場合に、ウレタンゴムを充分に崩壊させることができない場合がある。
中でも、硫酸ナトリウム、硫酸カリウムが、高吸水性ポリマーの不活化効率の点からより好ましい。 Examples of the alkali metal inorganic salt or alkaline earth metal inorganic salt (C) include sodium sulfate, sodium chloride, potassium sulfate, potassium chloride and the like, and it is preferable to use at least one selected from these. Calcium chloride, aluminum chloride, aluminum sulfate, magnesium chloride, and magnesium sulfate, which are shown in Patent Document 1, become hydroxides that are sparingly soluble in water under alkaline conditions. do not play a role. Moreover, since the hydroxyl groups in the water-based treatment agent are consumed as hydroxides, the pH of the water-based treatment agent is lowered, and there is a possibility that the stripping performance is lowered. Further, when urethane rubber is used as thread rubber, it may not be possible to sufficiently disintegrate the urethane rubber.
Among them, sodium sulfate and potassium sulfate are more preferable from the viewpoint of inactivation efficiency of the superabsorbent polymer.
本発明において使用する上記芳香族スルホン酸塩（Ｄ）は、上記極性溶媒（Ａ）等を均一に混合することができる成分である。芳香族スルホン酸塩（Ｄ）を用いることにより、各成分と水とを均一に混合することができる。各成分が均一に混合された水系処理剤とすることで、接着剤等に対して有効に作用する。 The aromatic sulfonate (D) used in the present invention is a component with which the polar solvent (A) and the like can be uniformly mixed. By using the aromatic sulfonate (D), each component and water can be uniformly mixed. By forming a water-based treatment agent in which each component is uniformly mixed, it acts effectively on adhesives and the like.
芳香族スルホン酸塩（Ｄ）は、トルエンスルホン酸塩、キシレンスルホン酸塩、キュメンスルホン酸塩、メトキシベンゼンスルホン酸塩等が挙げられ、これらから選択される少なくとも１種を用いることが好ましい。
上記トルエンスルホン酸塩、キシレンスルホン酸塩、キュメンスルホン酸塩及びメトキシベンゼンスルホン酸塩等としては、ナトリウム、カリウム、リチウム、カルシウムの塩が挙げられ、中でも、ナトリウム塩が好適である。 The aromatic sulfonate (D) includes toluenesulfonate, xylenesulfonate, cumenesulfonate, methoxybenzenesulfonate and the like, and it is preferable to use at least one selected from these.
Examples of the toluenesulfonate, xylenesulfonate, cumenesulfonate, methoxybenzenesulfonate, and the like include salts of sodium, potassium, lithium, and calcium, with sodium salts being preferred.
また、パラトルエンスルホン酸ナトリウム、キシレンスルホン酸ナトリウム、キュメンスルホン酸ナトリウム及びメトキシベンゼンスルホン酸ナトリウムを使用すると、上記のような可溶化剤的役割を果たして、上記極性溶媒等を均一に混合するだけでなく、高吸水性ポリマーの不活化も促進することができる点で好ましい。 In addition, when sodium p-toluenesulfonate, sodium xylenesulfonate, sodium cumenesulfonate, and sodium methoxybenzenesulfonate are used, they play the role of a solubilizer as described above, and can be obtained by simply mixing the polar solvent and the like uniformly. It is preferable in that it can accelerate the deactivation of the superabsorbent polymer.
本発明の水系処理剤には、上記の物質以外に、性能を損なわない程度に、可溶化剤として、プロピレングリコール、ジエチレングリコール、エチレングリコール等のグリコール系溶剤またはアルカノールアミン等を加えても良い。 In addition to the above substances, the water-based treatment agent of the present invention may contain, as a solubilizer, a glycol-based solvent such as propylene glycol, diethylene glycol, ethylene glycol, alkanolamine, or the like, as long as the performance is not impaired.
水系処理剤中、上記極性溶媒（Ａ）は、２０～９０質量％含まれていることが好ましい。含有量の下限は、より好ましくは３０質量％であり、更に好ましくは３５質量％であり、最も好ましくは４０質量％である。一方、含有量の上限は、より好ましくは６０質量％であり、更に好ましくは５０質量％である。
極性溶媒が、少なすぎると、接着剤除去能力が低下する傾向にあり、反対に、多すぎると、芳香族スルホン酸塩、無機系アルカリ化合物（Ｂ）、アルカリ金属無機塩又はアルカリ土類金属無機塩（Ｃ）等の固形分が析出する傾向にある。 The content of the polar solvent (A) in the water-based treatment agent is preferably 20 to 90% by mass. The lower limit of the content is more preferably 30% by mass, still more preferably 35% by mass, and most preferably 40% by mass. On the other hand, the upper limit of the content is more preferably 60% by mass, still more preferably 50% by mass.
If the polar solvent is too small, the ability to remove the adhesive tends to decrease. Solids such as salt (C) tend to precipitate.
水系処理剤中、上記無機系アルカリ化合物（Ｂ）は、１～１０質量％含まれていることが好ましい。含有量は、より好ましくは１～５質量％であり、更に好ましくは２～４．５質量％である。
無機系アルカリ化合物が少なすぎると、接着剤の除去能力が低下する場合があり、反対に、５質量％を超えると、劇物に指定されることから取り扱いが煩雑となる場合がある。また、無機系アルカリ化合物が少なすぎると、ウレタンゴムを糸ゴムとして使用している場合に、ウレタンゴムを充分に崩壊させることができない場合がある。 The inorganic alkaline compound (B) is preferably contained in an amount of 1 to 10% by mass in the water-based treatment agent. The content is more preferably 1 to 5% by mass, still more preferably 2 to 4.5% by mass.
If the amount of the inorganic alkaline compound is too small, the ability to remove the adhesive may be lowered. On the other hand, if the inorganic alkaline compound is too small, it may not be possible to sufficiently disintegrate the urethane rubber when the urethane rubber is used as thread rubber.
水系処理剤中、上記アルカリ金属無機塩又はアルカリ土類金属無機塩（Ｃ）は、０．５～５質量％含まれていることが好ましい。含有量の下限は、より好ましくは１質量％である。一方、含有量の上限は、より好ましくは３質量％であり、更に好ましくは２質量％である。
アルカリ金属無機塩又はアルカリ土類金属無機塩が、少なすぎると、高吸水性ポリマーの不活化効率が低下する傾向にあり、反対に、多すぎると、アルカリ金属無機塩又はアルカリ土類金属無機塩（Ｃ）等の固形分が析出する傾向にある。 The alkali metal inorganic salt or alkaline earth metal inorganic salt (C) is preferably contained in an aqueous treatment agent in an amount of 0.5 to 5% by mass. The lower limit of the content is more preferably 1% by mass. On the other hand, the upper limit of the content is more preferably 3% by mass, still more preferably 2% by mass.
If the alkali metal inorganic salt or alkaline earth metal inorganic salt is too small, the deactivation efficiency of the superabsorbent polymer tends to decrease. Solids such as (C) tend to precipitate.
水系処理剤中、上記芳香族スルホン酸塩（Ｄ）は、５～３０質量％含まれていることが好ましい。含有量の下限は、より好ましくは１２質量％であり、更に好ましくは１５質量％である。一方、含有量の上限は、より好ましくは２５質量％であり、更に好ましくは２０質量％である。
芳香族スルホン酸塩が、少なすぎると、極性溶媒が可溶化しなかったり、高吸水性ポリマーの不活化が充分になされなかったりする傾向にあり、反対に、多すぎると、芳香族スルホン酸塩（Ｄ）、無機系アルカリ化合物（Ｂ）、アルカリ金属無機塩又はアルカリ土類金属無機塩（Ｃ）等の析出が起こる傾向にある。 The aromatic sulfonate (D) is preferably contained in an aqueous treatment agent in an amount of 5 to 30% by mass. The lower limit of the content is more preferably 12% by mass, still more preferably 15% by mass. On the other hand, the upper limit of the content is more preferably 25% by mass, still more preferably 20% by mass.
If the aromatic sulfonate is too small, the polar solvent will not be solubilized, and the superabsorbent polymer will not be sufficiently inactivated. On the contrary, if it is too large, the aromatic sulfonate (D), inorganic alkali compounds (B), alkali metal inorganic salts or alkaline earth metal inorganic salts (C) tend to precipitate.
本発明の水系処理剤は、使用時に水を１０～５０質量％含むことが好ましい。なお、水を含まない処理剤を調整し、これを使用直前に所定量の水で希釈して使用するものであってもよい。このような場合の、水を含まない状態の水系処理剤も本発明に包含される。 The water-based treatment agent of the present invention preferably contains 10 to 50% by mass of water at the time of use. Alternatively, a water-free treatment agent may be prepared and diluted with a predetermined amount of water just before use. In such a case, the present invention also includes a water-free water-based treatment agent.
本発明の水系処理剤のｐＨは、１３．０以上であることが好ましい。ｐＨが１３．０以上であると、接着剤の除去能力に優れる。また、ウレタンゴムを糸ゴムとして使用している場合に、ウレタンゴムを充分に崩壊させることに寄与し得る。
本発明の水系処理剤は、アルカリ性であると、殺菌作用も期待できる。 The pH of the water-based treatment agent of the present invention is preferably 13.0 or higher. When the pH is 13.0 or higher, the adhesive is excellent in removing ability. Moreover, when urethane rubber is used as thread rubber, it can contribute to fully disintegrating urethane rubber.
If the water-based treatment agent of the present invention is alkaline, it can be expected to have a bactericidal action.
更に、本発明の水系処理剤は、キレート剤を含有していることが好ましい。キレート剤を含有することで、処理設備への、水由来のカルシウム等の金属スケールの付着防止という点で有利に働く。 Furthermore, the aqueous treatment agent of the present invention preferably contains a chelating agent. Containing a chelating agent works advantageously in preventing adhesion of water-derived metal scale such as calcium to treatment equipment.
上記キレート剤としては、アミノカルボン酸系キレート剤が好ましく、具体的には、ニトリロ三酢酸（ＮＴＡ）、エチレンジアミン四酢酸（ＥＤＴＡ）、ジエチレントリアミン五酢酸（ＤＴＰＡ）、ヒドロキシエチレンジアミン三酢酸（ＨＥＤＴＡ）、エチレンジアミン－Ｎ，Ｎ－ジコハク酸（ＥＤＤＳ）等が挙げられる。中でも、ＮＴＡがキレート力の点で好ましい。 As the chelating agent, an aminocarboxylic acid-based chelating agent is preferable, and specifically, nitrilotriacetic acid (NTA), ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA), hydroxyethylenediaminetriacetic acid (HEDTA), ethylenediamine. -N,N-disuccinic acid (EDDS) and the like. Among them, NTA is preferable in terms of chelating power.
また、上記キレート剤は１種でも、２種以上を併用してもよい。
また、キレート剤の含有量は、水系処理剤中、０．１～１．０質量％であることが好ましい。 The chelating agent may be used alone or in combination of two or more.
Also, the content of the chelating agent is preferably 0.1 to 1.0% by mass in the water-based treatment agent.
本発明の水系洗浄剤に、その他、非イオン界面活性剤、陰イオン界面活性剤、両性界面活性剤の内、１種以上配合しても良い。 In addition, one or more of nonionic surfactants, anionic surfactants and amphoteric surfactants may be added to the aqueous detergent of the present invention.
本発明の水系処理剤は、例えば、上記各原料と必要に応じて水とを、常法により、撹拌等行い、混合することにより調製すればよい。 The water-based treatment agent of the present invention may be prepared, for example, by mixing each of the above-mentioned raw materials and, if necessary, water by a conventional method such as stirring.
本発明の使用済みもしくは未使用の吸収性物品を処理する方法は、パルプ及び高吸水性ポリマーを含む吸収体、不織布並びにフィルムを、少なくとも構成部材として備える使用済みもしくは未使用の吸収性物品を処理する方法であって、
上記吸収性物品に、ＳＰ値が１０～１３である極性溶媒（Ａ）、無機系アルカリ化合物（Ｂ）、アルカリ金属塩又はアルカリ土類金属塩（Ｃ）、及び芳香族スルホン酸塩（Ｄ）を含有する水系処理剤を付与して、上記吸収性物品を上記構成部材毎に分解すると共に、上記高吸水性ポリマーを不活化する工程（１）、
工程（１）で分解された各構成部材を分離し、回収する工程（２）
を有するものである。 The method for treating used or unused absorbent articles of the present invention treats used or unused absorbent articles comprising at least an absorbent body containing pulp and a superabsorbent polymer, a nonwoven fabric, and a film as constituent members. a method for
The absorbent article contains a polar solvent (A) having an SP value of 10 to 13, an inorganic alkali compound (B), an alkali metal salt or alkaline earth metal salt (C), and an aromatic sulfonate (D). A step (1) of applying an aqueous treatment agent containing
Step (2) of separating and recovering each constituent member disassembled in step (1)
It has
上記工程（１）において、上記水系処理剤を、吸収性物品に付与する。その方法は、特に限定されるものではなく、適宜行えばよい。例えば、水系処理剤の入った容器やタンク等に、吸収性物品を投入することにより、水系処理剤に吸収性物品を浸漬する。
このとき、上記浸漬温度が７０～８０℃であることが好ましい。この温度範囲であれば、接着剤の除去が問題なく行える。
また、浸漬時間は、３０～６０分間であることが好ましい。
また、必要に応じて、プロペラを回転させること等により撹拌するようにしてもよい。 In the step (1), the water-based treatment agent is applied to the absorbent article. The method is not particularly limited, and may be performed as appropriate. For example, the absorbent article is immersed in the water-based treatment agent by placing the absorbent article in a container, tank, or the like containing the water-based treatment agent.
At this time, the immersion temperature is preferably 70 to 80°C. Within this temperature range, the adhesive can be removed without problems.
Also, the immersion time is preferably 30 to 60 minutes.
Moreover, if necessary, the mixture may be stirred by rotating a propeller or the like.
上記工程（１）において、水系処理剤により、構成部材同士を接合している接着剤が溶解し、吸収性物品は、吸収体、不織布、フィルム等の構成部材に分解する。本方法では、不織布やフィルムと、他の構成部材（フィルム又は不織布や吸収体等）との接合部分の接着剤を水系処理剤により除去するので、不織布やフィルムと他の構成部材とを、破断等せずにそのままの形状を維持したまま、それぞれに分解することができる。したがって、吸収性物品の不織布やフィルム等の構成部材を効率よく回収することができる。また、フィルムや不織布に接着剤を残さずに、分離することができることにより、不織布やフィルムを純度の高い樹脂として再利用可能となり、また、不織布やフィルムの再利用のときに接着剤が悪影響を及ぼすことを抑制できる。 In the above step (1), the water-based treating agent dissolves the adhesive that joins the constituent members together, and the absorbent article is decomposed into constituent members such as absorbent bodies, nonwoven fabrics, and films. In this method, since the adhesive at the joint between the nonwoven fabric or film and other constituent members (film, nonwoven fabric, absorber, etc.) is removed with a water-based treatment agent, the nonwoven fabric or film and other constituent members are not broken. It can be decomposed into each while maintaining the shape as it is without equalizing. Therefore, constituent members such as nonwoven fabrics and films of absorbent articles can be efficiently recovered. In addition, by separating the film and non-woven fabric without leaving any adhesive behind, the non-woven fabric or film can be reused as a highly pure resin, and the adhesive will not adversely affect the reuse of the non-woven fabric or film. can be suppressed.
また、上記工程（１）において、高吸水性ポリマーは不活化により脱水される。高吸収性ポリマーが脱水されることにより、吸収体の質量が大きく減少するので、分離、回収がし易くなる。また、脱水により、高吸収性ポリマーは粘度の低い状態になるので、不織布やフィルムに付着した高吸水性ポリマーを、それらから容易に分離することができる。 In the above step (1), the superabsorbent polymer is dehydrated by inactivation. Dehydration of the superabsorbent polymer greatly reduces the mass of the absorber, making separation and recovery easier. Moreover, since the superabsorbent polymer becomes less viscous by dehydration, the superabsorbent polymer adhering to the nonwoven fabric or film can be easily separated from them.
次に、工程（２）において、分解された各構成部材を分離し、回収する。分離する方法は、特に限定されるものではない。例えば、工程（１）で得られた混合液から、構成部材の浮力差を利用することによって、又は、不織布や篩等を用いて濾過することによって、それぞれの構成部材を分離し、回収する。
なお、本発明の処理方法においては、パルプと高吸収性ポリマーとは分離しておらず、これらが一体となっている吸収体として分離・回収される。
また、工程（２）においては、上記分離する前もしくは分離中に、又は、回収後に、水で洗浄するようにしてもよい。 Next, in step (2), each disassembled component is separated and recovered. The separation method is not particularly limited. For example, the constituent members are separated and recovered from the mixed liquid obtained in step (1) by utilizing the difference in buoyancy of the constituent members or by filtering using a nonwoven fabric, a sieve, or the like.
In the processing method of the present invention, the pulp and the superabsorbent polymer are not separated, but separated and recovered as an integrated absorbent.
Further, in the step (2), washing with water may be performed before or during the separation, or after recovery.
各々回収された、不織布、フィルム等は、必要に応じて、脱水し、加熱乾燥、すなわち室温よりも高い温度の雰囲気又は熱風により適宜乾燥させるとよい。 The recovered nonwoven fabric, film, etc. may be dehydrated and dried by heating, that is, dried in an atmosphere at a temperature higher than room temperature or in hot air, if necessary.
また、工程（２）において、クエン酸、リンゴ酸、コハク酸、フマル酸等の有機酸を含有する水を用いることで、中和を行うようにしてもよい。 In step (2), neutralization may be performed using water containing organic acids such as citric acid, malic acid, succinic acid, and fumaric acid.
本発明の方法を行うにあたっては、予め、使用済みもしくは未使用の吸収性物品を、洗浄剤等を含有する水で洗浄する工程を設けてもよいし、本方法が洗浄工程を兼ねたものであってもよい。 In carrying out the method of the present invention, a step of washing the used or unused absorbent article with water containing a detergent or the like may be provided in advance, or the method may also serve as the washing step. There may be.
上記のようにして回収された、不織布及びフィルムは、接着剤が付着していないため、再生利用に適したものである。 The nonwoven fabrics and films recovered as described above are suitable for recycling because they do not have an adhesive attached thereto.
また、回収された吸収体中のパルプと高吸水性ポリマーは、適宜公知の方法により、それぞれ分離し、回収するようにすればよい。回収されたパルプと高吸水性ポリマーは、それぞれ再利用され得る。 Moreover, the pulp and the superabsorbent polymer in the recovered absorbent body may be appropriately separated and recovered by a known method. The recovered pulp and superabsorbent polymer can each be reused.
本発明の処理方法により、ホットメルト接着剤を溶解させる工程の前に物理的な衝撃で吸収性物品の分解を行うことなく、また、１回の工程で、使用済みもしくは未使用の吸収性物品を構成部材毎に分解することができるので、効率的な、構成部材の分離・回収が可能となる。 According to the treatment method of the present invention, used or unused absorbent articles can be processed in a single step without degrading the absorbent article by physical impact prior to the step of dissolving the hot-melt adhesive. can be disassembled for each constituent member, efficient separation and collection of the constituent members is possible.
また、本発明の水系処理剤は、上記処理方法において、使用後回収し、必要に応じて、濃縮等の処理を行い、複数回再利用することができる。 In addition, the water-based treatment agent of the present invention can be recovered after use in the treatment method described above, subjected to treatment such as concentration as necessary, and reused multiple times.
以下、実施例に基づいて、本発明を具体的に説明する。なお、本発明は以下の実施例に限定されるものではない。実施例中、「部」「％」とある場合は、特に限定のない限りは、「質量部」「質量％」をあらわす。 EXAMPLES The present invention will be specifically described below based on examples. In addition, the present invention is not limited to the following examples. In the examples, "parts" and "%" represent "mass parts" and "mass%" unless otherwise specified.
（実施例１）
ジエチレングリコールモノブチルエーテル５０％、パラトルエンスルホン酸ナトリウム１５％、水酸化ナトリウム４．３％、ＮＴＡ０．３５％、硫酸ナトリウム１％、水３３％を混合して水系処理剤とした。
得られた水系処理剤を用いて、以下のホットメルト接着剤除去試験及び高吸水性ポリマーの不活化試験により評価した。また、得られた水系処理剤の可溶化状態についても評価した。
それらの結果を、表１に示す。 (Example 1)
50% diethylene glycol monobutyl ether, 15% sodium p-toluenesulfonate, 4.3% sodium hydroxide, 0.35% NTA, 1% sodium sulfate and 33% water were mixed to prepare an aqueous treatment agent.
Using the water-based treatment agent thus obtained, evaluation was made by the following hot-melt adhesive removal test and superabsorbent polymer deactivation test. In addition, the solubilization state of the resulting water-based treatment agent was also evaluated.
Those results are shown in Table 1.
＜可溶化判定＞
調製した剥離洗浄剤の可溶化状態を判定した。
　溶解：透明均一
　分離：分離もしくは固形分が析出 <Solubilization determination>
The solubilization state of the prepared stripping cleaner was determined.
Dissolution: Transparent and uniform Separation: Separation or precipitation of solids
＜ホットメルト接着剤除去試験＞
市販紙おむつ（花王製メリーズ（登録商標））を５ｃｍ×５ｃｍにカットし、水系処理剤５０ｇに、温度８０℃で３０分間浸漬させた後、下記の評価を行った。
 
　◎：ホットメルト接着剤が完全に除去されており、構成部材表面にべたつきがなかった。
　〇：紙おむつの構成部材毎に分解されているが、構成部材表面にわずかにべたつきがあった。
　△：紙おむつの構成部材毎に分解されているが、構成部材表面にべたつきが多くあった。
　×：紙おむつの構成部材毎に分解されていなかった。
  <Hot melt adhesive removal test>
A commercially available paper diaper (Merries (registered trademark) manufactured by Kao Corporation) was cut into 5 cm×5 cm pieces and immersed in 50 g of a water-based treatment agent at a temperature of 80° C. for 30 minutes, followed by the following evaluations.

A: The hot-melt adhesive was completely removed, and there was no stickiness on the surface of the component.
◯: The constituent members of the paper diaper were disassembled, but the surfaces of the constituent members were slightly sticky.
Δ: The constituent members of the paper diaper were disassembled, but there was much stickiness on the surfaces of the constituent members.
x: The constituent members of the disposable diaper were not disassembled.
＜高吸水性ポリマー（ＳＡＰ）の不活化（脱水性能）試験＞
（１）ＳＡＰとパルプ混合物１ｇ（ＳＡＰとパルプの質量比１：２）に、水道水５０ｇを加えて、ＳＡＰを膨潤させた。
（２）上記（１）に、水系処理剤５０ｇを加え、温度２５℃で、１分間静置した。
（３）不織布で濾過を行い、ＳＡＰとパルプの質量を測定し、測定した質量の小数点第１位を四捨五入し、下記により評価を行った。
 
　◎：濾過後のＳＡＰ＋パルプの質量が２５ｇ以下
　〇：濾過後のＳＡＰ＋パルプの質量が２６～３０ｇ
　△：濾過後のＳＡＰ＋パルプの質量が３１～３５ｇ
　×：濾過後のＳＡＰ＋パルプの質量が３６ｇ以上
  <Inactivation (dehydration performance) test of super absorbent polymer (SAP)>
(1) 50 g of tap water was added to 1 g of a mixture of SAP and pulp (mass ratio of SAP to pulp: 1:2) to swell the SAP.
(2) 50 g of a water-based treatment agent was added to the above (1), and the mixture was allowed to stand at a temperature of 25°C for 1 minute.
(3) Filtration was performed with a nonwoven fabric, the mass of SAP and pulp was measured, the measured mass was rounded off to the first decimal place, and the following evaluation was performed.

◎: The mass of SAP + pulp after filtration is 25 g or less ○: The mass of SAP + pulp after filtration is 26 to 30 g
△: The mass of SAP + pulp after filtration is 31 to 35 g
×: The mass of SAP + pulp after filtration is 36 g or more
（実施例２～９）
水系処理剤の組成を、表１に示すようにした他は、実施例１と同様にして、各試験を行った。
その結果を、表１に示す。 (Examples 2 to 9)
Each test was conducted in the same manner as in Example 1, except that the composition of the water-based treatment agent was as shown in Table 1.
The results are shown in Table 1.
（比較例１～１０）
処理剤の組成を、表２に示すようにした他は、実施例１と同様にして、各試験を行った。
その結果を、表２に示す。 (Comparative Examples 1 to 10)
Each test was conducted in the same manner as in Example 1, except that the composition of the treatment agent was as shown in Table 2.
The results are shown in Table 2.
表１の結果より、実施例１～９の水系処理剤は、ホットメルト接着剤の除去及びＳＡＰの脱水性能を満足するものであった。一方、表２の結果より、比較例１、２においては、極性溶媒が水に可溶化しておらず、溶液が分離しており、ＳＡＰの脱水性能が不充分であった。比較例５の水系処理剤も、ＳＡＰの脱水性能が不充分であった。また、比較例３、４、６～１０の水系処理剤は、ホットメルト接着剤の除去及びＳＡＰの脱水性能が不充分であった。 From the results in Table 1, the water-based treatment agents of Examples 1 to 9 were satisfactory in removing the hot-melt adhesive and dewatering the SAP. On the other hand, from the results in Table 2, in Comparative Examples 1 and 2, the polar solvent was not solubilized in water, the solution was separated, and the dehydration performance of SAP was insufficient. The water-based treatment agent of Comparative Example 5 also had insufficient SAP dehydration performance. In addition, the water-based treatment agents of Comparative Examples 3, 4, and 6 to 10 were insufficient in hot-melt adhesive removal and SAP dewatering performance.
（実施例１０～１６）
アルカリ金属塩及びアルカリ土類金属塩として、表３に示すものを使用した他は、実施例１と同様にして水系処理剤を作成し、下記方法によりＳＡＰの不活化試験を行った。その結果を、表３、図１及び図２に示す。 (Examples 10-16)
A water-based treatment agent was prepared in the same manner as in Example 1, except that the alkali metal salts and alkaline earth metal salts shown in Table 3 were used, and an inactivation test of SAP was performed by the following method. The results are shown in Table 3, FIGS. 1 and 2.
＜高吸水性ポリマー（ＳＡＰ）の不活化試験＞
（１）ＳＡＰとパルプ混合物１ｇ（ＳＡＰとパルプの質量比１：２）に、水道水５０ｇを加えて、ＳＡＰを膨潤させた。
（２）上記（１）に、水系処理剤５０ｇを加え、温度２５℃で、１分間静置した。
（３）不織布で濾過を行い、ＳＡＰとパルプの質量を測定した。 <Inactivation test of super absorbent polymer (SAP)>
(1) 50 g of tap water was added to 1 g of a mixture of SAP and pulp (mass ratio of SAP to pulp: 1:2) to swell the SAP.
(2) 50 g of a water-based treatment agent was added to the above (1), and the mixture was allowed to stand at a temperature of 25°C for 1 minute.
(3) Filtration was performed with a non-woven fabric, and the mass of SAP and pulp was measured.
また、得られた水系処理剤を用いて、上記ホットメルト接着剤除去試験を行った。 Moreover, the hot-melt adhesive removal test was conducted using the water-based treatment agent thus obtained.
更に、得られた水系処理剤を用いて、下記方法によりウレタンゴム崩壊試験を行った。
＜ウレタンゴム崩壊性試験＞
（１）市販紙おむつ（花王製メリーズ（登録商標））を５×５ｃｍ程度にカットし、糸ゴム（ウレタンゴム）を含有する部位を水系処理剤５０ｇに浸漬させた。
（２）８０℃に加温しながら、目視で糸ゴムの状態を観察し、下記により評価を行った。
 
〇：３時間以内でボロボロに崩壊し、原型を確認できなかった。
△：６時間以内で膨潤等のわずかな変化はあったが、原型を確認できた。
×：６時間以上経過後も形状に変化がなかった。
その結果を、表３に示す。 Furthermore, using the water-based treatment agent thus obtained, a urethane rubber disintegration test was carried out by the following method.
<Urethane rubber disintegration test>
(1) A commercially available paper diaper (Merries (registered trademark) manufactured by Kao Corporation) was cut into pieces of about 5×5 cm, and the portion containing rubber thread (urethane rubber) was immersed in 50 g of a water-based treatment agent.
(2) While heating to 80°C, the state of the thread rubber was visually observed and evaluated as follows.

O: Collapsed into tatters within 3 hours, and the prototype could not be confirmed.
Δ: Slight changes such as swelling occurred within 6 hours, but the original shape was confirmed.
x: There was no change in shape even after 6 hours or more.
The results are shown in Table 3.
（比較例１１）
上記（１）に、水道水５０ｇを加え、上記ＳＡＰの不活化試験を行い、ブランクとした。その結果を、図３に示す。
また、水道水５０ｇを用いて、上記ホットメルト接着剤除去試験及びウレタンゴム崩壊試験を行った。
それらの結果を、表４に示す。 (Comparative Example 11)
50 g of tap water was added to the above (1), and the above SAP inactivation test was performed to obtain a blank. The results are shown in FIG.
Also, using 50 g of tap water, the hot-melt adhesive removal test and the urethane rubber disintegration test were carried out.
Those results are shown in Table 4.
（比較例１２～２５）
上記（１）に、表４に示す配合比の処理剤５０ｇを加え、上記ＳＡＰの不活化試験を行った。その結果を、図３～図７に示す。
また、得られた処理剤を用いて、上記ホットメルト接着剤除去試験及び上記ウレタンゴム崩壊試験を行った。
その結果を、表４に示す。 (Comparative Examples 12 to 25)
To the above (1), 50 g of the treatment agent having the compounding ratio shown in Table 4 was added, and the SAP inactivation test was performed. The results are shown in FIGS. 3-7.
Also, the hot-melt adhesive removal test and the urethane rubber disintegration test were carried out using the obtained treatment agent.
The results are shown in Table 4.
図１及び図２より、実施例１０～１６の水系処理剤は、高吸水性ポリマーの不活化が良好であったことがわかる。また、ホットメルト除去性及びウレタンゴム崩壊性も良好であった。
一方、図３～７より、比較例１１～２５においては、高吸水性ポリマーの不活化が充分ではなかった。
なお、比較例１８の処理剤は、他の比較例に比べて、若干、ＳＡＰ＋パルプの重量が少なかったが、表４に示すように、ホットメルト除去性に劣り、ウレタンゴムを充分に崩壊させることができなかったものであることから、本発明の水系処理剤としては不十分であった。また、比較例２２～２４の処理剤も、他の比較例に比べて、若干、ＳＡＰ＋パルプの重量が少なかったが、ウレタンゴムを充分に崩壊させることができなかったものであることから、本発明の水系処理剤としては不十分であった。 1 and 2, it can be seen that the water-based treatment agents of Examples 10 to 16 were excellent in inactivating the superabsorbent polymer. Also, the hot-melt removability and urethane rubber disintegration property were good.
On the other hand, from FIGS. 3 to 7, in Comparative Examples 11 to 25, the superabsorbent polymer was not sufficiently inactivated.
The processing agent of Comparative Example 18 had a slightly smaller weight of SAP+pulp than the other comparative examples, but as shown in Table 4, it was inferior in hot-melt removability and sufficiently disintegrated the urethane rubber. Therefore, it was insufficient as the water-based treatment agent of the present invention. In addition, the processing agents of Comparative Examples 22 to 24 also had a slightly smaller weight of SAP+pulp than the other comparative examples. It was insufficient as an aqueous treatment agent of the invention.
（実施例１７～１９）
水系処理剤の組成を、表５に示すようにした他は、実施例１と同様にして、水系処理剤を作製した。
得られた水系処理剤を用いて、上記ＳＡＰの不活化（脱水性能）試験、上記ホットメルト接着剤除去試験及び上記ウレタンゴム崩壊試験を行った。
その結果を、表５に示す。 (Examples 17-19)
A water-based treatment agent was prepared in the same manner as in Example 1, except that the composition of the water-based treatment agent was changed as shown in Table 5.
Using the water-based treatment agent thus obtained, the SAP deactivation (dehydration performance) test, the hot-melt adhesive removal test, and the urethane rubber disintegration test were carried out.
The results are shown in Table 5.
（比較例２６～３２）
表６に示す配合比の処理剤５０ｇを用い、上記各試験を行った。
その結果を、表６に示す。 (Comparative Examples 26-32)
Using 50 g of the treatment agent having the compounding ratio shown in Table 6, each of the above tests was conducted.
The results are shown in Table 6.
表５の結果より、実施例１７～１９の水系処理剤は、各試験において良好な結果が得られた。一方、表６の結果より、比較例２６～３２においては、各試験全てにおいて満足する結果を得られたものはなかった。 From the results in Table 5, the aqueous treatment agents of Examples 17 to 19 gave good results in each test. On the other hand, according to the results in Table 6, in Comparative Examples 26 to 32, none of the tests gave satisfactory results.
本発明の水系処理剤は、使用済みもしくは未使用の使い捨て紙おむつ等の吸収性物品を分離・回収に好適である。 The aqueous treatment agent of the present invention is suitable for separating and recovering absorbent articles such as used or unused disposable diapers.

Claims (6)

  1. ＳＰ値が１０～１３である極性溶媒（Ａ）、無機系アルカリ化合物（Ｂ）、アルカリ金属無機塩又はアルカリ土類金属無機塩（Ｃ）、及び芳香族スルホン酸塩（Ｄ）を含有する、使用済みもしくは未使用吸収性物品を処理するための水系処理剤。 A polar solvent (A) with an SP value of 10 to 13, an inorganic alkali compound (B), an alkali metal inorganic salt or an alkaline earth metal inorganic salt (C), and an aromatic sulfonate (D). A water-based treatment for treating used or virgin absorbent articles.
  2. 上記極性溶媒（Ａ）が、ベンジルアルコール、フェノキシエタノール、及びジエチレングリコールモノブチルエーテルからなる群から選択される少なくとも１つである請求項１記載の水系処理剤。 2. The aqueous treating agent according to claim 1, wherein said polar solvent (A) is at least one selected from the group consisting of benzyl alcohol, phenoxyethanol and diethylene glycol monobutyl ether.
  3. 上記無機系アルカリ化合物（Ｂ）が、水酸化ナトリウム及び／又は水酸化カリウムである請求項１又は２記載の水系処理剤。 3. The water-based treatment agent according to claim 1, wherein the inorganic alkaline compound (B) is sodium hydroxide and/or potassium hydroxide.
  4. 上記アルカリ金属無機塩又はアルカリ土類金属無機塩（Ｃ）が、硫酸ナトリウム、塩化ナトリウム、塩化カリウム、及び硫酸カリウムからなる群から選択される少なくとも１つである請求項１～３いずれか１項に記載の水系処理剤。 Any one of claims 1 to 3, wherein the alkali metal inorganic salt or alkaline earth metal inorganic salt (C) is at least one selected from the group consisting of sodium sulfate, sodium chloride, potassium chloride, and potassium sulfate. The water-based treatment agent described in .
  5. 上記芳香族スルホン酸塩（Ｄ）が、トルエンスルホン酸塩、キシレンスルホン酸塩、キュメンスルホン酸塩、及びメトキシベンゼンスルホン酸塩からなる群から選択される少なくとも１種である請求項１～４いずれか１項に記載の水系処理剤。 Any one of claims 1 to 4, wherein the aromatic sulfonate (D) is at least one selected from the group consisting of toluenesulfonate, xylenesulfonate, cumenesulfonate, and methoxybenzenesulfonate. 1. The water-based treatment agent according to claim 1.
  6. パルプ及び高吸水性ポリマーを含む吸収体、不織布並びにフィルムを、少なくとも構成部材として備える使用済みもしくは未使用吸収性物品を処理する方法であって、
    上記吸収性物品に、ＳＰ値が１０～１３である極性溶媒（Ａ）、無機系アルカリ化合物（Ｂ）、アルカリ金属無機塩又はアルカリ土類金属無機塩（Ｃ）、及び芳香族スルホン酸塩（Ｄ）を含有する水系処理剤を付与して、上記吸収性物品を上記構成部材毎に分解すると共に、上記高吸水性ポリマーを不活化する工程（１）、
    工程（１）で分解された各構成部材を分離し、回収する工程（２）
    を有する使用済みもしくは未使用吸収性物品を処理する方法。     A method for treating used or virgin absorbent articles comprising as at least constituent members an absorbent body containing pulp and a superabsorbent polymer, a nonwoven fabric and a film, the method comprising the steps of:
    The absorbent article contains a polar solvent (A) having an SP value of 10 to 13, an inorganic alkali compound (B), an alkali metal inorganic salt or an alkaline earth metal inorganic salt (C), and an aromatic sulfonate ( Step (1) of applying an aqueous treatment agent containing D) to decompose the absorbent article into its constituent members and inactivate the superabsorbent polymer;
    Step (2) of separating and recovering each constituent member disassembled in step (1)
    A method of treating used or virgin absorbent articles having
PCT/JP2023/000054 2022-01-12 2023-01-05 Aqueous treatment agent for treating used or unused absorbent item, method for treating used or unused absorbent item using same WO2023136193A1 (en)

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