EP4626962A1 - Procédé de production de particules superabsorbantes de couleur stable - Google Patents

Procédé de production de particules superabsorbantes de couleur stable

Info

Publication number
EP4626962A1
EP4626962A1 EP23808810.8A EP23808810A EP4626962A1 EP 4626962 A1 EP4626962 A1 EP 4626962A1 EP 23808810 A EP23808810 A EP 23808810A EP 4626962 A1 EP4626962 A1 EP 4626962A1
Authority
EP
European Patent Office
Prior art keywords
alkyl
arylalkyl
general formula
compound
pyrazole
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
EP23808810.8A
Other languages
German (de)
English (en)
Inventor
Christian HILS
Christophe Bauduin
Jan Niclas GORGES
Matthias Weismantel
Ruediger Funk
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
BASF SE
Original Assignee
BASF SE
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by BASF SE filed Critical BASF SE
Publication of EP4626962A1 publication Critical patent/EP4626962A1/fr
Pending legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J3/00—Processes of treating or compounding macromolecular substances
    • C08J3/24—Crosslinking, e.g. vulcanising, of macromolecules
    • C08J3/245—Differential crosslinking of one polymer with one crosslinking type, e.g. surface crosslinking
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61L—METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES
    • A61L15/00—Chemical aspects of, or use of materials for, bandages, dressings or absorbent pads
    • A61L15/16—Bandages, dressings or absorbent pads for physiological fluids such as urine or blood, e.g. sanitary towels, tampons
    • A61L15/42—Use of materials characterised by their function or physical properties
    • A61L15/60—Liquid-swellable gel-forming materials, e.g. super-absorbents
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
    • B01J20/22—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising organic material
    • B01J20/26—Synthetic macromolecular compounds
    • B01J20/265—Synthetic macromolecular compounds modified or post-treated polymers
    • B01J20/267—Cross-linked polymers
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J3/00—Processes of treating or compounding macromolecular substances
    • C08J3/02—Making solutions, dispersions, lattices or gels by other methods than by solution, emulsion or suspension polymerisation techniques
    • C08J3/03—Making solutions, dispersions, lattices or gels by other methods than by solution, emulsion or suspension polymerisation techniques in aqueous media
    • C08J3/075—Macromolecular gels
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J3/00—Processes of treating or compounding macromolecular substances
    • C08J3/12—Powdering or granulating
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K5/00—Use of organic ingredients
    • C08K5/16—Nitrogen-containing compounds
    • C08K5/34—Heterocyclic compounds having nitrogen in the ring
    • C08K5/3442—Heterocyclic compounds having nitrogen in the ring having two nitrogen atoms in the ring
    • C08K5/3445—Five-membered rings
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J2333/00—Characterised by the use of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides, or nitriles thereof; Derivatives of such polymers
    • C08J2333/02—Homopolymers or copolymers of acids; Metal or ammonium salts thereof

Definitions

  • the present invention relates to a process for producing color-stable superabsorbent particles, wherein an aqueous monomer solution or suspension is polymerized to form a polymer gel, the polymer gel obtained is optionally comminuted, the polymer gel is then dried, the dried polymer gel is optionally ground and classified, the dried polymer gel is then thermally surface-crosslinked and cooled, characterized in that after polymerization it is coated with a pyrazole.
  • Superabsorbents are used to produce diapers, tampons, sanitary napkins and other hygiene articles, but also as water-retaining agents in agricultural horticulture.
  • the pyrazole is usually a monomeric pyrazole.
  • the pyrazole used in the process according to the invention is preferably a compound of the general formula (I) where R 1 is C 1 or C 2 alkyl, R 2 is H, C 1 to C 20 alkyl or C 6 to C 20 arylalkyl and R 3 is H, C 1 to C 20 alkyl or C 6 to C 20 arylalkyl, or a compound of the general formula (II) 221049 3 where R 4 is C 1 or C 2 alkyl, R 5 is H, C 1 to C 20 alkyl or C 6 to C 20 arylalkyl and R 6 is H, C 1 to C 20 alkyl or C 6 to C 20 arylalkyl, or a compound of the general formula (III) where R 7 is C 1 or C 2 alkyl, R 8 is H, C 1 to C 20 alkyl or C 6 to C 20 arylalkyl and R 9 is H, C 1 to C 20 alkyl or
  • the alkyl groups can be straight, branched and/or cyclic.
  • the pyrazole used in the process according to the invention is particularly preferably a compound of the general formula (I) 221049 4 where R 1 is C 1 alkyl, R 2 is C 1 to C 3 alkyl or C 6 to C 8 arylalkyl and R 3 is H, C 1 to C 3 alkyl or C 6 to C 8 arylalkyl, or a compound of the general formula (II) where R 4 is C 1 alkyl, R 5 is C 1 to C 3 alkyl or C 6 to C 8 arylalkyl and R 6 is C 1 to C 3 alkyl or C 6 to C 8 arylalkyl, or a compound of the general formula (III) 221049 5 where R 7 is C 1 alkyl, R 8 is H, C 1 to C 3 alkyl or C 6 to C 8 arylalkyl and R 9 is C 1 to C 3 alkyl or C 6 to C 8 arylal
  • the water content of the monomer solution is preferably from 40 to 75% by weight, particularly preferably from 45 to 70% by weight, very particularly preferably from 50 to 65% by weight. As the water content increases, the energy required for the subsequent drying increases, and as the water content decreases, the heat of polymerization can only be dissipated insufficiently.
  • the temperature of the monomer solution is preferably from 10 to 90°C, particularly preferably from 20 to 70°C, very particularly preferably from 30 to 50°C.
  • the preferred polymerization inhibitors require dissolved oxygen for optimal effect.
  • the monomer solution can therefore be freed of dissolved oxygen before polymerization by inerting, ie by flowing an inert gas, preferably nitrogen or carbon dioxide, through it.
  • an inert gas preferably nitrogen or carbon dioxide
  • the oxygen content of the monomer solution before polymerization is reduced to less than 1 ppm by weight, more preferably to less than 0.5 ppm by weight, most preferably to less than 0.1 ppm by weight. 221049 8
  • Suitable reactors for polymerization are, for example, kneading reactors or belt reactors.
  • the polymer gel formed during the polymerization of an aqueous monomer solution or suspension is continuously comminuted by, for example, counter-rotating agitator shafts, as described in WO 2001/038402 A1.
  • Polymerization on the belt is described, for example, in DE 3825366 A1 and US 6,241,928.
  • Polymerization in a belt reactor produces a polymer gel that must be comminuted, for example in an extruder or kneader.
  • the comminuted polymer gel obtained by means of a kneader can also be extruded.
  • the polymer gel is then usually dried using a circulating air belt dryer until the residual moisture content is preferably 0.5 to 10% by weight, particularly preferably 1 to 7% by weight, very particularly preferably 2 to 5% by weight, the residual moisture content being determined according to test method no. WSP 230.2-05 "Mass Loss Upon Heating" recommended by EDANA. If the residual moisture is too high, the dried polymer gel has a glass transition temperature T g that is too low and is difficult to process further. If the residual moisture is too low, the dried polymer gel is too brittle and undesirably large amounts of polymer particles with too small a particle size ("fines") are produced in the subsequent comminution steps.
  • the solids content of the polymer gel before drying is preferably between 25 and 90% by weight, particularly preferably between 35 and 70% by weight, very particularly preferably between 40 and 60% by weight.
  • the dried polymer gel is then broken and optionally coarsely crushed.
  • the dried polymer gel is then usually ground and classified, whereby single or multi-stage roller mills, preferably two or three-stage roller mills, pin mills, hammer mills or vibrating mills can usually be used for grinding.
  • the average particle size of the polymer particles separated as a product fraction is preferably from 150 to 850 ⁇ m, particularly preferably from 250 to 600 ⁇ m, very particularly from 300 to 500 ⁇ m.
  • the average particle size of the product fraction can be determined using the test method No.
  • WSP 220.2 (05) "Particle Size Distribution” recommended by EDANA, whereby the mass fractions of the sieve fractions are plotted cumulatively and the average particle size is determined graphically.
  • the average particle size is the value of the mesh size that results for a cumulative 50 wt.%. 221049 9
  • the polymer particles are thermally surface-crosslinked to further improve their properties. Suitable surface-crosslinkers are compounds that contain groups that can form covalent bonds with at least two carboxylate groups of the polymer particles.
  • Suitable compounds are, for example, polyfunctional amines, polyfunctional amidoamines, polyfunctional epoxides, as described in EP 0083022 A2, EP 0543303 A1 and EP 0937736 A2, di- or polyfunctional alcohols, as described in DE 3314019 A1, DE 35 23617 A1 and EP 0450922 A2, or ß-hydroxyalkylamides, as described in DE 10204938 A1 and US 6,239,230.
  • the amount of surface post-crosslinker is preferably 0.001 to 2% by weight, particularly preferably 0.01 to 1% by weight, very particularly preferably 0.03 to 0.7% by weight, based in each case on the polymer particles.
  • polyvalent cations are applied to the particle surface in addition to the surface post-crosslinkers.
  • the polyvalent cations that can be used in the process according to the invention are, for example, divalent cations, such as the cations of zinc, magnesium, calcium and strontium, trivalent cations, such as the cations of aluminum, iron, chromium, rare earths and manganese, tetravalent cations, such as the cations of titanium and zirconium.
  • Suitable dryers include Hosokawa Bepex® Horizontal Paddle Dryer (Hosokawa Micron GmbH; Leingart; Germany), Hosokawa Bepex® Disc Dryer (Hosokawa Micron GmbH; Leingart; Germany), Holo-Flite® dryers (Metso Minerals Industries Inc.; Danville; USA) and Nara Paddle Dryer (NARA Machinery Europe; Frechen; Germany). Fluidized bed dryers can also be used. Surface post-crosslinking can take place in the mixer itself by heating the jacket or blowing in warm air. A downstream dryer, such as a tray dryer, a rotary kiln or a heatable screw, is also suitable. Mixing and thermal surface post-crosslinking are particularly advantageous in a fluidized bed dryer.
  • the pyrazole is preferably a compound of the general formula (I) where R 1 is C 1 or C 2 alkyl, R 2 is H, C 1 to C 20 alkyl or C 6 to C 20 arylalkyl and R 3 is H, C 1 to C 20 alkyl or C 6 to C 20 arylalkyl, 221049 12 or a compound of general formula (II) where R 4 is C 1 or C 2 alkyl, R 5 is H, C 1 to C 20 alkyl or C 6 to C 20 arylalkyl and R 6 is H, C 1 to C 20 alkyl or C 6 to C 20 arylalkyl, or a compound of the general formula (III) where R 7 is C 1 or C 2 alkyl, R 8 is H, C 1 to C 20 alkyl or C 6 to C 20 arylalkyl and R 9 is H, C 1 to C 20 alkyl or C 6 to C 20 arylalkyl.
  • R 1 is C 1 or C 2 alkyl
  • the alkyl groups can be straight, branched and/or cyclic.
  • the compounds of the general formula (I) are in equilibrium with their keto form.
  • 1,3-dimethyl-5-pyrazolone is the keto form of 1,3-dimethyl-5-hydroxypyrazole.
  • the pyrazole is very particularly preferably 1,3-dimethyl-5-pyrazolone, 1,5-dimethyl-3-ethyl-4-hydroxypyrazole or 1,5-dimethyl-4-hydroxy-3-phenylpyrazole.
  • the superabsorbent particles were coated with preferably 0.001 to 1% by weight, particularly preferably 0.005 to 0.2% by weight, very particularly preferably 0.01 to 0.1% by weight of the pyrazole, based in each case on the polymer particles.
  • % aqueous ascorbic acid solution were used per t of monomer solution.
  • the monomer solution was dosed into a List Contikneter reactor with a volume of 6.3 m3 (LIST AG, Arisdorf, Switzerland). The throughput of the monomer solution was approximately 20 t/h.
  • the reaction solution had a temperature of 23.5°C at the inlet.
  • the monomer solution was rendered inert with nitrogen between the addition point for the crosslinker and the addition points for the hydrogen peroxide and sodium peroxodisulfate solutions.
  • Ascorbic acid was dosed directly into the reactor.
  • the surface crosslinker solution contained 1.35 wt.% ethylene glycol diglycidyl ether, 44.84 wt.% 1,2-propanediol and 53.81 wt.% water. After drying, the surface crosslinked polymer particles were cooled to approx. 60°C in a NARA paddle cooler (GMF Gouda, Waddinxveen, Netherlands).

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  • Chemical & Material Sciences (AREA)
  • Health & Medical Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Organic Chemistry (AREA)
  • Polymers & Plastics (AREA)
  • Medicinal Chemistry (AREA)
  • Dispersion Chemistry (AREA)
  • Analytical Chemistry (AREA)
  • Materials Engineering (AREA)
  • General Health & Medical Sciences (AREA)
  • Public Health (AREA)
  • Veterinary Medicine (AREA)
  • Animal Behavior & Ethology (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Epidemiology (AREA)
  • Engineering & Computer Science (AREA)
  • Hematology (AREA)
  • Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)
  • Processes Of Treating Macromolecular Substances (AREA)
  • Absorbent Articles And Supports Therefor (AREA)
  • Polymerisation Methods In General (AREA)

Abstract

La présente invention concerne un procédé de production de particules superabsorbantes de couleur stable, selon lequel une solution aqueuse de monomère ou une suspension de monomère est polymérisée pour former un gel polymère, le gel polymère obtenu est éventuellement broyé, le gel polymère est ensuite séché, le gel polymère séché est éventuellement broyé et classifié, le gel polymère séché est par la suite réticulé thermiquement en surface et refroidi, le revêtement étant caractérisé en ce qu'il est réalisé avec un pyrazole après polymérisation.
EP23808810.8A 2022-11-29 2023-11-20 Procédé de production de particules superabsorbantes de couleur stable Pending EP4626962A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
EP22210280 2022-11-29
PCT/EP2023/082340 WO2024115160A1 (fr) 2022-11-29 2023-11-20 Procédé de production de particules superabsorbantes de couleur stable

Publications (1)

Publication Number Publication Date
EP4626962A1 true EP4626962A1 (fr) 2025-10-08

Family

ID=84519455

Family Applications (1)

Application Number Title Priority Date Filing Date
EP23808810.8A Pending EP4626962A1 (fr) 2022-11-29 2023-11-20 Procédé de production de particules superabsorbantes de couleur stable

Country Status (6)

Country Link
EP (1) EP4626962A1 (fr)
JP (1) JP2025539867A (fr)
KR (1) KR20250116010A (fr)
CN (1) CN120265687A (fr)
TW (1) TW202432680A (fr)
WO (1) WO2024115160A1 (fr)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2025202003A1 (fr) * 2024-03-28 2025-10-02 Basf Se Inhibiteurs de polymérisation

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Also Published As

Publication number Publication date
TW202432680A (zh) 2024-08-16
WO2024115160A1 (fr) 2024-06-06
CN120265687A (zh) 2025-07-04
KR20250116010A (ko) 2025-07-31
JP2025539867A (ja) 2025-12-09

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