EP2934411A1 - Superabsorbant inhibant les odeurs - Google Patents

Superabsorbant inhibant les odeurs

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Publication number
EP2934411A1
EP2934411A1 EP13818685.3A EP13818685A EP2934411A1 EP 2934411 A1 EP2934411 A1 EP 2934411A1 EP 13818685 A EP13818685 A EP 13818685A EP 2934411 A1 EP2934411 A1 EP 2934411A1
Authority
EP
European Patent Office
Prior art keywords
superabsorbent
superabsorber
decanediol
weight
acid
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.)
Withdrawn
Application number
EP13818685.3A
Other languages
German (de)
English (en)
Inventor
Asif Karim
Thomas Daniel
Christine SCHÖN
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
Priority to EP13818685.3A priority Critical patent/EP2934411A1/fr
Publication of EP2934411A1 publication Critical patent/EP2934411A1/fr
Withdrawn legal-status Critical Current

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Classifications

    • 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
    • A61L15/46—Deodorants or malodour counteractants, e.g. to inhibit the formation of ammonia or bacteria
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F13/00—Bandages or dressings; Absorbent pads
    • A61F13/15—Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators
    • A61F13/53—Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators characterised by the absorbing medium
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F13/00—Bandages or dressings; Absorbent pads
    • A61F13/15—Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators
    • A61F13/84—Accessories, not otherwise provided for, for absorbent pads
    • A61F13/8405—Additives, e.g. for odour, disinfectant or pH control
    • 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
    • A61L15/20—Bandages, dressings or absorbent pads for physiological fluids such as urine or blood, e.g. sanitary towels, tampons containing organic materials
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61L—METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES
    • A61L15/00—Chemical aspects of, or use of materials for, bandages, dressings or absorbent pads
    • A61L15/16—Bandages, dressings or absorbent pads for physiological fluids such as urine or blood, e.g. sanitary towels, tampons
    • A61L15/22—Bandages, dressings or absorbent pads for physiological fluids such as urine or blood, e.g. sanitary towels, tampons containing macromolecular materials
    • A61L15/24—Macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds; Derivatives thereof
    • 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
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C31/00—Saturated compounds having hydroxy or O-metal groups bound to acyclic carbon atoms
    • C07C31/18—Polyhydroxylic acyclic alcohols
    • C07C31/20—Dihydroxylic alcohols
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F13/00—Bandages or dressings; Absorbent pads
    • A61F13/15—Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators
    • A61F13/53—Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators characterised by the absorbing medium
    • A61F2013/530481—Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators characterised by the absorbing medium having superabsorbent materials, i.e. highly absorbent polymer gel materials
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F13/00—Bandages or dressings; Absorbent pads
    • A61F13/15—Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators
    • A61F13/84—Accessories, not otherwise provided for, for absorbent pads
    • A61F13/8405—Additives, e.g. for odour, disinfectant or pH control
    • A61F2013/8408—Additives, e.g. for odour, disinfectant or pH control with odour control
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
    • F04C2270/00—Control; Monitoring or safety arrangements
    • F04C2270/04—Force
    • F04C2270/041—Controlled or regulated

Definitions

  • Odor-inhibiting superabsorber The present invention relates to an odor-inhibiting superabsorber, a process for its preparation and its use, hygiene articles containing it and processes for their preparation.
  • Superabsorbents are known. Also, for such materials, terms such as “high swellable polymer” “hydrogel” (often used for the dry form), “hydrogel-forming polymer”, “water-absorbent polymer”, “absorbent gelling material”, “swellable resin”, “ Water-absorbent resin “, water-absorbing polymer” or the like in common use.
  • crosslinked hydrophilic polymers in particular polymers of (co) polymerized hydrophilic monomers, graft (co) polymers of one or more hydrophilic monomers on a suitable graft base, crosslinked cellulose or starch ethers, crosslinked carboxymethylcellulose, partially crosslinked polyalkylene oxide or in aqueous Liquid swellable natural products, such as guar derivatives, with superabsorbents based on partially neutralized acrylic acid are the most common.
  • the essential properties of superabsorbents are their ability to absorb many times their own weight in aqueous fluids and, to some extent, the fluid as well
  • the superabsorber which is used in the form of a dry powder, transforms into a gel when it absorbs liquid, with the usual absorption of water corresponding to a hydrogel.
  • Crosslinking is essential for synthetic superabsorbents and an important difference to conventional pure thickeners, as it leads to the insolubility of the polymers in water. Soluble substances would not be useful as superabsorbent.
  • the most important application of superabsorbents is the absorption of body fluids.
  • Superabsorbents are used, for example, in infant diapers, adult incontinence products or feminine hygiene products. Other fields of application are, for example, those used as water-retaining agents in agricultural horticulture, as water storage for protection against fire, for liquid absorption in food packaging or, more generally, for the absorption of moisture.
  • Superabsorbents can absorb several times their own weight in water and retain them under some pressure.
  • such a superabsorber has a CRC ("Centrifuge Retention Capacity", measuring method see below) of at least 5 g / g, preferably at least 10 g / g and in a particularly preferred form at least 15 g / g
  • CRC Chiptrifuge Retention Capacity
  • Important for a superabsorbent is not only its absorption capacity, but also the ability to retain liquid under pressure (retention) and the liquid transport in the swollen state.
  • Swollen gel can hinder fluid transport to superabsorbers that are not yet swollen ("gel blocking") .
  • Good transport properties for liquids include, for example, hydrogels which have a high gel strength in the swollen state Gels with only low gel strength are under an applied pressure (body pressure) deforming clogs pores in the superabsorbent / cellulosic fiber absorbent to prevent further fluid ingestion
  • Increased gel strength is usually achieved by a higher degree of cross-linking, which however reduces the absorbent capacity of the product
  • An elegant method of increasing gel strength is to increase the gel strength Degree of crosslinking at the surface of the superabsorbent particles with respect to the interior of the particles.
  • dried superabsorber particles having an average crosslinking density are usually additional crosslinking in a thin surface layer of their particles.
  • Surface postcrosslinking increases the crosslink density in the shell of the superabsorbent particles, raising the absorption under pressure to a higher level. While the absorption capacity in the surface layer of the superabsorbent particles decreases, its core has an improved absorption capacity compared to the shell due to the presence of mobile polymer chains, so that the shell construction ensures improved fluid transfer without gel blocking occurring. It is also known to produce overall higher crosslinked superabsorbents and to subsequently reduce the degree of crosslinking in the interior of the particles compared to an outer shell of the particles.
  • Acrylic acid-based superabsorbents which are most commonly used in the marketplace, are prepared by the radical polymerization of acrylic acid in the presence of a crosslinker (the "internal crosslinker"), the acrylic acid before, after or partly before, partly after the polymerization to a certain extent
  • the polymer gel obtained in this way is comminuted (depending on the polymerization reactor used, this can take place simultaneously with the polymerization) and dried, the dry powder obtained in this way (the “base polymer” or " Base polymer ”) is usually post-crosslinked on the surface of the particles by reacting with other crosslinkers such as organic crosslinkers or polyvalent cations, for example aluminum (usually used as aluminum sulfate) or both, to produce a more highly crosslinked surface layer to the interior of the particle.
  • crosslinkers such as organic crosslinkers or polyvalent cations, for example aluminum (usually used as aluminum sulfate) or both, to produce a more highly crosslinked surface layer to the interior of the particle.
  • Odors can be masked by perfuming, resulting ammonia or amines can be removed by absorption or reaction, and microbial degradation can be inhibited by, for example, biocides or urease inhibitors. These measures can be applied on the one hand to the superabsorber and on the other hand to the hygiene article.
  • Odors can be masked by perfuming, resulting ammonia or amines can be removed by absorption or reaction, and microbial degradation can be inhibited by, for example, biocides or urease inhibitors.
  • EP 1 358 894 A1 teaches hygiene articles which may contain a number of odor-inhibiting additives, in particular anhydride groups, acid groups, cyclodextrins, biocides, surfactants with an HLB Value less than 1 liter, absorbents such as zeolites, clay, activated carbon, silicon dioxide or activated alumina, microorganisms which act as antagonists to undesired odor-causing microorganisms, pH buffers or chelating agents WO 03/076 514 A2 provides a comprehensive overview of the well-known measures to avoid unpleasant odors Among other things, the use of biocides such Bronopol or glyoxylic acid is disclosed For example, this reference discloses a superabsorbent containing anhydride
  • EP 202 127 A2 teaches according to the hygiene article with a pH buffer such as an organic acid or acid-modified cellulose, which keeps the pH of the skin in the range of 3.0 to 5.5.
  • EP 316 518 A2 relates to superabsorbents of partially neutralized polymeric organic acid which are optionally additionally mixed with partially neutralized citric acid and which, when in contact with liquid, have a pH of between 5.0 and 6.0.
  • WO 03/002 623 A1 teaches superabsorbers having a pH below 5.7.
  • GB 2 296 013 A describes sanitary articles which contain a polylactide layer so that lactic acid is formed on liquid contact, whereby the pH is lowered.
  • WO 00/35502 A1 teaches hygiene articles with a combination of a buffer having a pH in the range 3.5-5.5 and lactic acid bacteria.
  • a superabsorbent is used which is functional Contains groups which can react with ammonia or amines, in particular cyclic anhydrides, lactides or lactones of hydroxy acids.
  • WO 01/32 226 A1 discloses a superabsorber mixed with organic acids.
  • EP 894 502 A1 teaches the use of cyclodextrins as absorbent for ammonia in sanitary articles.
  • EP 1 034 800 A1 discloses hygiene articles which, in addition to an absorbent for ammonia, in particular activated carbon, high surface area silicon dioxide, clays, zeolites, kieselguhr, chitin, pH buffers, starch, cyclodextrin or ion exchangers, also contain oxidizing agents such as peracids or diacyl peroxides.
  • WO 91/1 1 977 A1 relates to zeolites having an SiO 2 / Al 2 O 3 ratio below 10 as odor absorbents. According to WO 95/26 207 A1, zeolites with an average particle size of at least 200 micrometers are used for this purpose.
  • EP 1 149 597 A1 chitosan is described as an odor-inhibiting component of hygiene articles.
  • EP 1 149 593 A1 teaches cationic polysaccharides, in particular chitin derivatives or chitosan, in conjunction with a pH buffer which adjusts the pH in the range from 3.5 to 6.
  • EP 739 635 A1 teaches sodium meta- and tetraborate as urease inhibitors in superabsorbents.
  • a mixture of alkali metal or alkaline earth metal tetraborate and boric acid, citric acid, tartaric acid or ascorbic acid is used as the buffer in the pH range from 7 to 10.
  • WO 03/053486 A1 discloses diapers containing yucca palm extract as a urease inhibitor.
  • EP 1 214 878 A1 discloses the use of chelate complexes of divalent metal ions, such as the copper complex of the singly protonated ethylenediamine tetraacetate as urease inhibitor.
  • WO 95/24173 A2 teaches odor control with bactericidal heavy metals such as silver, zinc or copper impregnated zeolites.
  • EP 31 1 344 A23 relates to hygiene articles which contain a biocide such as alkyl ammonium halides or bisguanidines in addition to a pH buffer.
  • EP 389 023 A2 discloses sanitary articles with an odor control additive selected from biocides or absorbents, in particular molecular sieves.
  • WO 98/26 808 A2 describes superabsorbents which contain cyclodextrins, zeolites, activated carbon, kieselguhr or acid salt-forming substances as absorbents for odors, as well as biocides, urease inhibitors and pH regulators for inhibiting odor formation.
  • a superabsorbent which is coated with a biocide, such as benzalkonium chloride or chlorhexidine, is used in hygiene articles.
  • WO 2007/012 581 A1 relates to storage-stable superabsorbents with substituted thiophosphoric triamides as odor inhibitors.
  • WO 2009/034 154 A2 and WO 201 1/023 647 A1 relate to triclosan-containing superabsorbents.
  • WO 201 1/023 560 A2 discloses odor-inhibiting superabsorbers which contain zinc peroxide.
  • EP 1 269 983 A1 teaches that 1, 2-decanediol, applied topically, that is applied to the skin, inhibits the growth of germs causing germs on a human or animal body and thus avoids body odors, especially underarm and foot odor. About avoiding odors, as they occur in gradual bacterial decomposition of urine or fecal matter, this document teaches nothing.
  • biocides or antibiotics in sanitary articles is disadvantageous because these substances by diffusion come into contact with the skin of the user and thereby unfold their effects not only against odor-causing bacteria, but also in an undesirable manner.
  • their use in disposing of the sanitary articles used in the usual way leads to a significant release of biocides or antibiotics into the environment, which not only affects the function of sewage treatment plants, but also contributes to the formation of antibiotic-resistant bacterial strains. Similar undesirable effects are also associated with the use of heavy bactericidal metals such as zinc, silver or copper.
  • the superabsorbers according to the invention lead to the avoidance or at least reduction of unpleasant odors after contact with body fluids.
  • the absorption and retention behavior of the superabsorbent is not significantly impaired by the 1,2-decanediol. It is not necessary, but possible, to use acidic superabsorbent to use sorber.
  • the 1, 2-decanediol does not affect storage stability, unwanted effects on skin contact or in the environment were neither observed nor expected.
  • a process for the preparation of the superabsorbent according to the invention uses of this superabsorbent as well as hygiene articles containing this superabsorbent and processes for their preparation have been found.
  • the superabsorbent according to the invention generally contains at least 0.01% by weight of 1,2-decanediol, preferably at least 0.1% by weight and more preferably at least 0.5% by weight of 1,2-decanediol, in each case obtained on the total weight of the superabsorbent.
  • the superabsorbent according to the invention contains at most 10% by weight of 1,2-decanediol, preferably at most 8% by weight and most preferably at most 5% by weight, in each case based on the total weight of the superabsorbent. Examples of suitable levels for most applications are about 1 wt .-% or 2 wt .-%, each based on the total weight of the superabsorbent.
  • the upper limit of this proportion by weight is determined by economic considerations rather than by technical considerations: the content of 1,2-decanediol increases the time until odors occur and it is not economical in typical applications of superabsorbers, especially in hygiene products such as diapers makes sense to extend this period of time beyond the typical wearing time of such hygiene products.
  • the superabsorbent contains 1, 2-n-decanediol.
  • the superabsorbent according to the invention is a conventional superabsorber, which can contain in particular in addition to 1, 2-decanediol all known other additives, ingredients or excipients.
  • the superabsorber according to the invention is preferably surface postcrosslinked.
  • the process according to the invention for the preparation of the superabsorbents according to the invention differs from known polymerization processes for the preparation of superabsorbents only in that 1,2-decanediol is added to the superabsorbent.
  • any known process for producing superabsorbents can be carried out by addition of 1, 2-decanediol according to the invention.
  • an existing superabsorber 1 2-decanediol is added.
  • the superabsorber can simply be mixed with 1,2-decanediol.
  • Masterbatch technique can likewise be used for this, ie a superabsorber containing no 1,2-decanediol with a significantly higher amount than desired in the end product 1, 2-Decandiol containing superabsorbent are mixed in such a way that the final mixture contains the desired amount of 1, 2-decanediol.
  • 1, 2-Decanediol can be added as a solid, as a melt or in suspension or solution.
  • 1, 2-decanediol is added as a solution, as the solvent can serve any solvent in which dissolves the applied amount of 1, 2-decanediol.
  • suitable examples are alcohols such as methanol, ethanol, n- and iso-propanol, n-, iso and sec-butanol.
  • 1,2-decanediol preferably takes place after drying or, if surface postcrosslinking, after surface postcrosslinking. If still other procedural steps are performed, which are associated with a heat treatment of the superabsorber, the 1, 2-decanediol is preferably added after the last heat treatment. This avoids an otherwise possible loss of 1, 2-decanediol due to the principle possible effect of diols as heatnnachvernetzer.
  • a temperature of the superabsorbent of at least 50 ° C, preferably at least 55 ° C, and more preferably at least 60 ° C, and at most 150 ° C, preferably at most 120 ° C and most preferably at most 100 ° C is suitable ,
  • a preferred polymerization process according to the invention for the preparation of acrylate superabsorbents containing 1,2-decanediol is the aqueous solution polymerization of a monomer mixture comprising at least one ethylenically unsaturated, acid group-carrying monomer, which is optionally present at least partially as a salt,
  • the monomers a) are preferably water-soluble, ie the solubility in water at 23 ° C. is typically at least 1 g / 100 g of water, preferably at least 5 g / 100 g of water, more preferably at least 25 g / 100 g of water, most preferably at least 35 g / 100 g of water.
  • Suitable monomers a) are, for example, ethylenically unsaturated carboxylic acids or their salts, such as acrylic acid, methacrylic acid, maleic acid, maleic anhydride, and itaconic acid or its salts.
  • Particularly preferred monomers are acrylic acid and methacrylic acid. Very particular preference is given to acrylic acid.
  • Suitable monomers a) are, for example, ethylenically unsaturated sulfonic acids, such as styrenesulfonic acid and 2-acrylamido-2-methylpropanesulfonic acid (AMPS).
  • sulfonic acids such as styrenesulfonic acid and 2-acrylamido-2-methylpropanesulfonic acid (AMPS).
  • AMPS 2-acrylamido-2-methylpropanesulfonic acid
  • a suitable monomer a) is, for example, an acrylic acid purified according to WO 2004/035514 A1 with 99.8460% by weight of acrylic acid, 0.0950% by weight of acetic acid,
  • the proportion of acrylic acid and / or salts thereof in the total amount of monomers a) is preferably at least 50 mol%, particularly preferably at least 90 mol%, very particularly preferably at least 95 mol%.
  • the monomer solution preferably contains at most 250 ppm by weight, preferably at most 130 ppm by weight, more preferably at most 70 ppm by weight and preferably at least 10 ppm by weight, more preferably at least 30 ppm by weight, in particular by 50% by weight.
  • ppm, hydroquinone half ethers based in each case on the unneutralized monomer a), where neutralized monomer a), ie a salt of the monomer a) is mathematically taken into account as unneutralized monomer.
  • an ethylenically unsaturated, acid group-carrying monomer having a corresponding content of hydroquinone half-ether can be used to prepare the monomer solution.
  • Preferred hydroquinone half ethers are hydroquinone monomethyl ether (MEHQ) and / or alpha tocopherol (vitamin E).
  • Suitable crosslinkers b) are compounds having at least two groups suitable for crosslinking. Such groups are, for example, ethylenically unsaturated groups which can be radically copolymerized into the polymer chain, and functional groups which can form covalent bonds with the acid groups of the monomer a). Furthermore, polyvalent metal salts which can form coordinative bonds with at least two acid groups of the monomer a) are also suitable as crosslinking agents b).
  • Crosslinkers b) are preferably compounds having at least two polymerizable groups which can be incorporated in the polymer network in free-radically polymerized form.
  • Suitable crosslinkers b) are, for example, ethylene glycol dimethacrylate, diethylene glycol diacrylate, polyethylene glycol diacrylate, allyl methacrylate, trimethylolpropane triacrylate, triallylamine, tetraallylammonium chloride, tetraallyloxyethane, as described in EP 530 438 A1, di- and triacrylates, as in EP 547 847 A1, EP 559 476 A1, EP 632,068 A1, WO 93/21237 A1, WO 2003/104299 A1, WO 2003/104300 A1, WO 2003/104301 A1 and DE 103 31 450 A1, mixed acrylates which, in addition to acrylate groups, contain further ethylenically unsaturated groups, as in DE 103 31 456 A1 and DE 103 55 401 A1, or crosslinker mixtures, as described, for example, in DE 195 43 368 A1, DE 196 46 484 A1, WO 90/15830 A1
  • Preferred crosslinkers b) are pentaerythritol triallyl ether, tetraallyloxyethane, methylenebismethacrylamide, trimethylolpropane triacrylate 10 to 20 times ethoxylated, trimethylolethane triacrylate 10 to 20 times ethoxylated, particularly preferably 15-times ethoxylated trimethylolpropane triacylate, polyethylene glycol diacrylates having 4 to 30 ethylene oxide units in the polyethylene glycol chain , Trimethylolpropantriacrylat, di- and triacrylates of 3 to 30-fold ethoxylated glycerol, particularly preferably di- and triacrylates of 10-20-fold ethoxylated glycerol, and triallylamine.
  • the polyols which are not completely esterified with acrylic acid can also be present here as Michael adducts with themselves, as a result of which tetra-, penta- or even higher acrylates may also
  • Very particularly preferred crosslinkers b) are the polyethyleneglyoxylated and / or propoxylated glycerols esterified with acrylic acid or methacrylic acid to form diioder triacrylates, as described, for example, in WO 2003/104301 A1.
  • Particularly advantageous are di- and / or triacrylates of 3- to 10-fold ethoxylated glycerol.
  • diacrylates or triacrylates of 1 to 5 times ethoxylated and / or propoxylated glycerol.
  • Most preferred are the triacrylates of 3 to 5 times ethoxylated and / or propoxylated glycerol, in particular the triacrylate of 3-times ethoxylated glycerol.
  • the amount of crosslinker b) is preferably from 0.05 to 1, 5 wt .-%, particularly preferably 0.1 to 1 wt .-%, most preferably 0.3 to 0.6 wt .-%, each based on Monomer a).
  • the centrifuge retention capacity (CRC) decreases and the absorbance increases under a pressure of 0.3 psi (AUL 0.3 psi).
  • initiators c) it is possible to use all compounds which generate free radicals under the polymerization conditions, for example thermal initiators, redox initiators, photoinitiators.
  • Suitable redox initiators are sodium peroxodisulfate / ascorbic acid, hydrogen peroxide / ascorbic acid, sodium peroxodisulfate / sodium bisulfite and hydrogen peroxide / sodium bisulfite.
  • mixtures of thermal initiators and redox initiators are used, such as sodium peroxodisulfate / hydrogen peroxide / ascorbic acid.
  • a reducing component but is preferably a mixture of the sodium salt of 2-hydroxy-2-sulfinatoacetic acid, the disodium salt of 2-hydroxy-2-sulfonatoacetic acid and Sodium bisulfite used (as Brüggolit ® FF6M or Brüggolit ® FF7, alternatively BRUGGOLITE ® FF6M or BRUGGOLITE ® FF7 available from L. Brüggemann KG, Salz
  • Examples of ethylenically unsaturated monomers d) which can be copolymerized with the ethylenically unsaturated monomers having acid groups are acrylamide, methacrylamide, hydroxyethyl acrylate, hydroxyethyl methacrylate, dimethylaminoethyl methacrylate, dimethylaminoethyl acrylate, dimethylaminopropyl acrylate, diethylaminopropyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, maleic acid and maleic anhydride.
  • water-soluble polymers e it is possible to use polyvinyl alcohol, polyvinylpyrrolidone, starch, starch derivatives, modified cellulose, such as methylcellulose or hydroxyethylcellulose, gelatin, polyglycols or polyacrylic acids, preferably starch, starch derivatives and modified cellulose.
  • an aqueous monomer solution is used.
  • the water content of the monomer solution is preferably from 40 to 75% by weight, more preferably from 45 to 70% by weight, most preferably from 50 to 65% by weight. It is also possible monomer suspensions, i. to use supersaturated monomer solutions. With increasing water content, the energy expenditure increases during the subsequent drying and with decreasing water content, the heat of polymerization can only be dissipated insufficiently.
  • the monomer solution can be freed of dissolved oxygen prior to the polymerization by inerting, ie by flowing with an inert gas, preferably nitrogen or carbon dioxide.
  • 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 less than 0.5 ppm by weight, most preferably less than 0.1 ppm by weight.
  • the monomer mixture may contain other components. Examples of other components used in such monomer mixtures include chelating agents to keep metal ions in solution. Furthermore, all known in superabsorbent production other additives can be used for monomer mixture.
  • Suitable polymerization reactors are, for example, kneading reactors or belt reactors.
  • the polymer gel formed in the polymerization of an aqueous monomer solution or suspension is comminuted continuously by, for example, counter-rotating stirring shafts, as described in WO 2001/38402 A1.
  • the polymerization on the belt is described, for example, in DE 38 25 366 A1 and US Pat. No. 6,241,928.
  • Polymerization in a belt reactor produces a polymer gel which must be comminuted in a further process step, for example in a meat grinder, extruder or kneader. But it can also be spherical Superabsorbent particles are prepared by suspension, spray or Tropfenpolymerisations vide.
  • the acid groups of the polymer gels obtained are usually partially neutralized.
  • the neutralization is preferably carried out at the stage of the monomers, in other words, salts of the acid group-carrying monomers or, strictly speaking, a mixture of acid group-carrying monomers and salts of the acid group-carrying monomers ("partially neutralized acid") are used as component a) in the polymerization
  • the degree of neutralization is preferably from 25 to 95 mol%, particularly preferably from 50 to 80 mol, usually by mixing the neutralizing agent as an aqueous solution or preferably also as a solid in the monomer mixture intended for the polymerization or preferably in the acid group-carrying monomer or a solution thereof.
  • % very particularly preferably from 65 to 72 mol%
  • the customary neutralizing agents preferably alkali metal hydroxides, alkali metal oxides, alkali metal carbonates or alkali metal hydrogencarbonates and mixtures thereof instead of alkali metal salts
  • Ammonium salts can also be used.
  • Sodium and potassium are particularly preferred as alkali metal cations, but most preferred are sodium hydroxide, sodium carbonate or sodium bicarbonate and mixtures thereof. But it is also possible to carry out the neutralization after the polymerization at the stage of Polymergeis formed during the polymerization.
  • the polymer gel is at least partially neutralized after the polymerization, the polymer gel is preferably comminuted mechanically, for example by means of an extruder, wherein the neutralizing agent can be sprayed, sprinkled or poured on and then thoroughly mixed in. For this purpose, the gel mass obtained can be extruded several times for homogenization.
  • the monomer a) is a mixture of from 25 to 95 mol%, particularly preferably from 50 to 80 mol%, very particularly preferably from 65 to 72 mol% salt of the acid group-carrying monomer and the remainder used to 100 mol% acid group-carrying monomer.
  • This mixture is, for example, a mixture of sodium acrylate and acrylic acid or a mixture of potassium acrylate and acrylic acid.
  • a neutralizing agent is used for neutralization, the content of iron is generally below 10 ppm by weight, preferably below 2 ppm by weight, and more preferably below 1 ppm by weight. Similarly, a low content of chloride and anions of oxygen acids of the chlorine is desired.
  • a suitable one Neutralizing agent is, for example, the 50 wt .-% sodium hydroxide solution or potassium hydroxide solution, usually traded as "membrane grade", more pure and preferred, but also more expensive is the 50% strength by weight sodium hydroxide solution usually sold as "amalgam grade" or "mercury process” or caustic potash.
  • the polymer gel obtained from the aqueous solution polymerization and optionally subsequent neutralization is then preferably dried with a belt dryer until the residual moisture content is preferably 0.5 to 15 wt .-%, particularly preferably 1 to 10 wt .-%, most preferably 2 to 8 wt .-%, is (measurement method for the residual moisture or water content, see below). If the residual moisture content is too high, the dried polymer gel has too low a glass transition temperature Tg and is difficult to process further.
  • the solids content of the gel before drying is generally from 25 to 90% by weight .-%, preferably from 30 to 80 wt .-%, particularly preferably from 35 to 70 wt .-%, most preferably from 40 to 60 wt .-%.
  • the dryer may be operated under nitrogen or other non-oxidizing inert gas, or at least under reduced partial pressure of oxygen, to prevent oxidative yellowing, but usually results in a mechanical mixing element such as a paddle dryer or similar dryer also adequate ventilation and drainage of the water steam to an acceptable product.
  • a mechanical mixing element such as a paddle dryer or similar dryer also adequate ventilation and drainage of the water steam to an acceptable product.
  • Advantageous in terms of color and product quality is usually the shortest possible drying time.
  • the usual mode of operation for this purpose is a temperature of the gas used for drying of at least 50.degree. C., preferably at least 80.degree. C. and more preferably at least 100.degree. C. and generally at most 250.degree.
  • the residual monomer content in the polymer particles also decreases and the last residues of the initiator are destroyed.
  • polymerization and drying take place essentially simultaneously, ie at the outlet of the polymerization reactor, a dry product is obtained immediately and no separate drying step is carried out, or optionally, optionally, to further reduce the water content in the product.
  • the dried polymer gel is then optionally ground and optionally classified.
  • the desired particle size distributions of the superabsorbent can be set in the polymerization step. If this is the case, milling and classification may be omitted or at best serve to remove an undesired proportion of particles that are too large or too small.
  • All known mills can be used, such as single or multi-stage roller mills, preferably two- or three-stage roller mills, pin mills, hammer mills or vibratory mills.
  • Oversized gel lumps which are often not dried in the interior, are rubber-elastic, lead to grinding problems and are preferably separated before grinding, which can easily be achieved by air classification or a sieve ("protective sieve" for the mill) is to be chosen in view of the mill used so that as possible no interference from oversized, rubber-elastic particles occur.
  • Superabsorbent particles which are too large are perceivable as coarse particles in their predominant use, in hygiene products such as diapers, and they also reduce the average swelling rate of the superabsorbent. Both are undesirable.
  • coarse-grained polymer particles are separated from the product. This is done by customary classification methods, for example air classification or sieving through a sieve with a mesh size of at most 1000 ⁇ m, preferably at most 900 ⁇ m, more preferably at most 850 ⁇ m and very particularly preferably at most 800 ⁇ m. For example, screens are used with 700 ⁇ , 650 ⁇ or 600 ⁇ mesh size.
  • the separated coarse-grained polymer particles (“oversize”) can be fed back to the grinding and screening circuit for cost optimization or further processed separately.
  • SFC permeability
  • also fine-grained polymer particles are separated in this classification. This can, if sieved, conveniently through a sieve with a mesh size of at most 300 ⁇ , preferably at most 200 ⁇ , more preferably at most 150 ⁇ and most preferably at most 100 ⁇ done.
  • the separated fine-grained polymer particles (“undersize” or “fines”) can be fed back to the monomer stream, the polymerizing gel, or the polymerized gel before drying the gel for cost optimization.
  • the mean particle size of the polymer particles obtained as a product fraction is generally at least 200 ⁇ m, preferably at least 250 ⁇ m, and preferably at least 300 ⁇ m, and generally at most 600 ⁇ m, and more preferably at most 500 ⁇ m.
  • the proportion of particles having a particle size of at least 150 ⁇ m is generally at least 90% by weight, preferably at least 95% by weight and most preferably at least 98% by weight.
  • the proportion of particles with a particle size of at most 850 ⁇ , is generally at least 90 wt .-%, preferably at least 95 wt .-% and most preferably at least 98 wt .-%.
  • the polymer produced in this way has superabsorbent properties and is referred to as "superabsorbent.” Its CRC is typically comparatively high, while its AUL or SFC is comparatively low.
  • the superabsorbent particles are optionally postcrosslinked on their surface to further improve the properties, in particular increase the AUL and SFC values (the CRC value generally decreases)
  • Suitable postcrosslinkers are compounds which contain groups which contain at least Acrylic acid / sodium acrylate-based superabsorbents which are predominant in the market are suitable surface postcrosslinker compounds containing groups having at least two carboxylate groups n can form bonds. Postcrosslinkers and postcrosslinking processes are known, any known postcrosslinker and any known postcrosslinking process can be used.
  • postcrosslinkers are 2-oxazolidone, N-methyl-2-oxazolidone, N- (2-hydroxyethyl) -2-oxazolidone and N-hydroxypropyl-2-oxazolidone; 1, 3-propanediol, 1, 5-pentanediol, 1, 6-hexanediol and 1, 7-heptanediol, 1, 3-butanediol, 1, 8-octanediol, 1, 9-nonanediol and 1, 10-decanediol; Butan-1, 2,3-triol, butane-1, 2,4-triol, glycerol, trimethylolpropane, trimethylolethane, pentaerythritol, 1 to 3 times ethoxylated glycerol, trimethylolethane or trimethylolpropane per molecule and 1 to 3 per molecule partially propoxylated glycerine, trimethylolethan
  • the postcrosslinker is generally used in an amount of at least 0.001% by weight, preferably at least 0.02% by weight, more preferably at least 0.05% by weight and generally not more than 2% by weight. , preferably at most 1 wt .-%, in a particularly preferred form at most 0.3 wt .-%, for example at most 0.15 wt .-% or at most 0.095 wt .-% used, each based on the mass of the base polymer.
  • the postcrosslinking is usually carried out so that a solution of the postcrosslinker is sprayed onto the dried base polymer particles.
  • the polymer particles coated with postcrosslinker are thermally dried, wherein the postcrosslinking reaction can take place both before and during the drying.
  • the spraying of the postcrosslinker solution is preferably carried out in mixers with moving mixing tools, such as screw mixers, disc, paddle or paddle mixers or mixers with other mixing tools. However, particularly preferred are vertical mixers. However, it is also possible to spray the postcrosslinker solution in a fluidized bed.
  • suitable ® mixers are, for example, as a plowshare mixer from Gebr Lödige Maschinenbau GmbH, Elsener Street.
  • the postcrosslinkers are typically used as an aqueous solution. If only water is used as the solvent, the postcrosslinker solution or already the base polymer is advantageously added to a surfactant or Deagglomerisationsangesmittel.
  • the aqueous postcrosslinker solution may also contain a cosolvent in addition to the at least one postcrosslinker.
  • a cosolvent in addition to the at least one postcrosslinker.
  • the penetration depth of the postcrosslinker can be adjusted in the polymer particles.
  • C 1 -C 6 -alcohols such as methanol, ethanol, n-propanol, isopropanol, n-butanol, sec-butanol, tert-butanol or 2-methyl-1-propanol
  • C 2 -C 5 -diols such as Ethylene glycol, 1, 2-propylene glycol or 1, 4-butanediol
  • ketones such as acetone
  • carboxylic acid esters such as ethyl acetate.
  • the concentration of the at least one postcrosslinker in the aqueous postcrosslinker solution is typically from 1 to 20% by weight, preferably from 1 to 5% by weight, particularly preferably from 2 to 5% by weight, based on the postcrosslinker solution.
  • the total amount of Nachvernetzerates based on the base polymer is usually from 0.3 to 15 wt .-%, preferably from 2 to 6 wt .-%.
  • the actual surface postcrosslinking by reaction of the surface postcrosslinker with functional groups on the surface of the base polymer particles is usually carried out by heating the base polymer wetted with surface postcrosslinker solution, commonly called “drying” (but not to be confused with the above described drying of the polymer gel from the polymerization, typically Drying can be carried out in the mixer itself, by heating the jacket, by heat exchange surfaces or by blowing warm gases in.
  • Simultaneous addition of the superabsorber with surface postcrosslinker and drying can take place, for example, in a fluidized bed dryer usually in a downstream dryer, such as a tray dryer, a rotary kiln, a paddle or disc dryer or a heated screw performed llust as Solidair ® or Torusdisc ® -T Rockner from Bepex International LLC, 333 NE Taft Street, Minneapolis, MN 55413, USA, or as a paddle or paddle dryer or as a fluidized bed dryer of Nara Machinery Co., Ltd., branch Europa, Europa Allee 46, 50226 Frechen, Germany available.
  • a downstream dryer such as a tray dryer, a rotary kiln, a paddle or disc dryer or a heated screw performed llustrated as Solidair ® or Torusdisc ® -T Rockner from Bepex International LLC, 333 NE Taft Street, Minneapolis, MN 55413, USA, or as a paddle or paddle dryer or as a fluidized bed dryer
  • Preferred drying temperatures are in the range 100 to 250 ° C, preferably 120 to 220 ° C, more preferably 130 to 210 ° C, most preferably 150 to 200 ° C.
  • Thieves- preferred residence time at this temperature in the reaction mixer or dryer is preferably at least 10 minutes, more preferably at least 20 minutes, most preferably at least 30 minutes, and usually at most 60 minutes.
  • the drying is conducted so that the superabsorbent has a residual moisture content of generally at least 0.1% by weight, preferably at least 0.2% by weight, and more preferably at least 0.5% by weight, and generally at most 15% by weight, preferably at most 10% by weight and in a particularly preferred form at most 8% by weight.
  • polyvalent cations can be applied to the particle surface in addition to the postcrosslinkers.
  • This is in principle a further surface postcrosslinking by ionic, noncovalent bonds, but is sometimes also referred to as "complexing" with the metal ions in question or simply as “coating” with the substances in question (the “complexing agent”).
  • complexing agent Compounds of such metal ions and methods of application are known, any known metal ion, any known compound thereof and any known method of application may be used.
  • polyvalent cations is usually carried out by spraying solutions of divalent or polyvalent cations, usually divalent, trivalent or tetravalent metal cations, but also polyvalent cations such formally wholly or partially from vinylamine monomers built polymers such as partially or completely hydrolyzed polyvinylamide (so-called "Polyvinylamine”), whose amine groups are always partially protonated to ammonium groups, even at very high pH values
  • divalent metal cations which may be used are, in particular, the divalent cations of metals of groups 2 (in particular Mg, Ca, Sr, Ba), 7 ( in particular Mn), 8 (in particular Fe), 9 (in particular Co), 10 (in particular Ni), 11 (in particular Cu) and 12 (in particular Zn) of the Periodic Table of the Elements
  • trivalent metal cations which may be used are in particular the trivalent cations of metals of the groups 3 including the lanthanides (in particular Sc, Y, La, Ce) , 8
  • tetravalent cations are, in particular, the tetravalent cations of metals of the lanthanides (in particular Ce) and of group 4 (in particular Ti, Zr, Hf) of the Periodic Table of the Elements.
  • the metal cations can be used alone or mixed with each other. Particularly preferred is the use of trivalent metal cations. Very particularly preferred is the use of aluminum cations.
  • metal salts which have sufficient solubility in the solvent to be used are suitable.
  • metal salts with weakly complexing anions such as chloride, nitrate and sulfate, hydrogen sulfate, carbonate, bicarbonate, nitrate, phosphate, hydrogen phosphate, or dihydrogen phosphate.
  • Preferred are salts of mono- and dicarboxylic acids, hydroxy acids, keto acids as well as amino acids or basic salts. Examples which may be mentioned are preferably acetates, propionates, tartrates, maleates, citrates, lactates, malates, succinates. Also preferred is the use of hydroxides.
  • 2-hydroxycarboxylic acid salts such as citrates and lactates.
  • particularly preferred metal salts are alkali metal and alkaline earth metal aluminates and their hydrates, such as sodium aluminate and its hydrates, alkali metal and alkaline earth metal lactates and citrates and their hydrates, aluminum acetate, aluminum propionate, aluminum citrate and aluminum lactate.
  • the cations and salts mentioned can be used in pure form or as a mixture of various cations or salts.
  • the salts of the two and / or trivalent metal cation used may contain further secondary constituents such as unneutralized carboxylic acid and / or alkali metal salts of the neutralized carboxylic acid.
  • Preferred alkali metal salts are those of sodium, potassium and ammonium. They are typically used as an aqueous solution, which is obtained by dissolving the solid salts in water, or is preferably produced directly as such, whereby optionally drying and cleaning steps are avoided.
  • the hydrates of said salts can be used, which often dissolve faster in water than the anhydrous salts.
  • the amount of metal salt used is generally at least 0.001% by weight, preferably at least 0.01% by weight and in a particularly preferred form at least 0.1% by weight, for example at least 0.4% by weight, and also Generally at most 5 wt .-%, preferably at most 2.5 wt .-% and in a particularly preferred form at most 1 wt .-%, for example at most 0.7 wt .-% in each case based on the mass of the base polymer.
  • the salt of the trivalent metal cation can be used as a solution or suspension.
  • solvents for the metal salts water, alcohols, DMF, DMSO and mixtures of these components can be used. Particularly preferred are water and water / alcohol mixtures such as water / methanol, water / 1, 2-propanediol and water / 1, 3-propanediol.
  • the treatment of the base polymer with solution of a divalent or polyvalent cation is carried out in the same way as with surface postcrosslinkers, including the drying step.
  • Surface postcrosslinker and polyvalent cation can be sprayed in a common solution or as separate solutions.
  • the spraying of the metal salt solution onto the superabsorbent particles can be carried out both before and after the surface postcrosslinking.
  • the spraying of the metal salt solution is carried out in the same step by spraying the crosslinker solution, wherein both solutions are sprayed separately successively or simultaneously via two nozzles, or crosslinker and metal salt solution can be sprayed together via a nozzle ,
  • additives known in the surface postcrosslinking of superabsorbents are basic salts of a divalent metal cation. ons such as calcium or strontium, usually as hydroxides, bicarbonates, carbonates, acetates, propionates, citrates, gluconates, lactates, tartrates, malates, succinates, maleates and / or fumarates.
  • reducing compounds such as hypophosphites, phosphonic acid derivatives, sulfinates or sulfites.
  • a drying step is carried out after the surface postcrosslinking and / or treatment with complexing agent, it is advantageous, but not absolutely necessary, to cool the product after drying.
  • the cooling can be continuous or discontinuous, conveniently the product is continuously conveyed to a dryer downstream cooler.
  • Any apparatus known for removing heat from powdered solids may be used for this purpose, in particular any apparatus mentioned above as a drying apparatus, unless it is supplied with a heating medium but with a cooling medium, such as cooling water, so that over the walls and depending on the construction no heat is also introduced into the superabsorber via the stirring elements or other heat exchange surfaces, but is removed therefrom.
  • coolers in which the product is moved ie cooled mixers, for example blade coolers, disk coolers or paddle coolers.
  • the superabsorbent can also be cooled in the fluidized bed by blowing in a cooled gas such as cold air. The conditions of the cooling are set so that a superabsorbent is obtained with the temperature desired for further processing.
  • an average residence time in the condenser of generally at least 1 minute, preferably at least 3 minutes and more preferably at least 5 minutes and generally at most 6 hours, preferably at most 2 hours and more preferably at most 1 hour is set and the cooling capacity is so such that the product obtained has a temperature of generally at least 0 ° C, preferably at least 10 ° C and more preferably at least 20 ° C and generally at most 100 ° C, preferably at most 80 ° C and in a particularly preferred form at most 60 ° C.
  • the surface postcrosslinked superabsorbent is optionally ground and / or sieved in the usual way. Grinding is typically not required here, but usually the setting of the desired particle size distribution of the product requires the screening of formed agglomerates. glomerates or fine grain attached. Agglomerates and fines are either discarded or preferably recycled to the process in a known manner and at a suitable location; Agglomerates after comminution.
  • the particle sizes desired for surface postcrosslinked SAPs are the same as for base polymers.
  • any known coatings such as film-forming polymers, thermoplastic polymers, dendrimers, polycationic polymers (such as, for example, polyvinylamine, polyethyleneimine or polyallylamine), water-insoluble, can be applied to the surface of the superabsorber particles, whether postcrosslinked or postcrosslinked, in the process.
  • polycationic polymers such as, for example, polyvinylamine, polyethyleneimine or polyallylamine
  • polyvalent metal salts such as, for example, magnesium carbonate, magnesium oxide, magnesium hydroxide, calcium carbonate, calcium sulfate or calcium phosphate, all water-soluble mono- or polyvalent metal salts known to the person skilled in the art, for example aluminum sulfate, sodium, potassium, zirconium or iron salts, or hydrophilic inorganic particles, such as clay minerals, fumed silica, colloidal silica sols such as Levasil ®, Titandi- oxide, aluminum oxide and magnesium oxide, are additionally applied.
  • useful alkali metal salts are sodium and potassium sulfate, sodium and potassium lactates, citrates, sorbates.
  • additives are used and sprayed in the form of dispersions, then they are preferably used as aqueous dispersions, and it is preferably additionally applied a dedusting agent for fixing the additive on the surface of the superabsorbent.
  • the dedusting agent is then added either directly to the dispersion of the inorganic powder additive, optionally it may also be added as a separate solution before, during, or after the inorganic powdery additive has been applied by spraying.
  • the simultaneous spraying of postcrosslinking agent, dedusting agent and powdery inorganic additive in the postcrosslinking is added separately in the cooler, for example by spraying from above, below or from the side.
  • Particularly suitable dedusting agents which can also serve to fix powdery inorganic additives on the surface of the superabsorbent particles, are polyethylene glycols having a molecular weight of 400 to 20 000 g / mol, polyglycerol, 3 to 100-fold ethoxylated polyols, such as trimethylolpropane, glycerol, Sorbitol and neopentyl glycol.
  • Particularly suitable are 7- to 20-tuply ethoxylated glycerol or trimethylolpropane, for example Polyol TP (per- Storp, SE) 70 ®.
  • the latter have the particular advantage that they only insignificantly reduce the surface tension of an aqueous extract of the superabsorbent particles.
  • the superabsorbers according to the invention are provided with further additives which stabilize against discoloration.
  • examples are in particular known stabilizers against Discoloration, in particular reducing substances.
  • solid or dissolved salts of phosphinic acid (H3PO2) as well as these are themselves preferred.
  • all phosphinates of the alkali metals, including ammonium, and the alkaline earth metals are suitable.
  • Particular preference is given to aqueous solutions of phosphinic acid which contain phosphinones and at least one cation selected from among sodium, potassium, ammonium, calcium, strontium, aluminum, magnesium.
  • salts of phosphonic acid (H3PO3) and these themselves.
  • phosphonic acid which contain primary and / or secondary phosphonations and at least one cation selected from sodium, potassium, calcium, strontium.
  • All coatings, solids, additives and auxiliaries can each be added in separate process steps, but most often the most convenient method is to add them to the superabsorber in the cooler, if not added during the displacement of the base polymer with surface postcrosslinker, such as by spraying a solution or Addition in finely divided solid or in liquid form.
  • the superabsorbent according to the invention generally has a centrifuge retention capacity (CRC) of at least 5 g / g, preferably of at least 10 g / g and in a particularly preferred form of at least 20 g / g. Further suitable minimum values of the CRC are, for example, 25 g / g, 30 g / g or 35 g / g. Usually it is not above 40 g / g. A typical range of CRC for surface postcrosslinked superabsorbents is from 28 to 33 g / g.
  • the superabsorbent according to the invention when surface postcrosslinked, typically has an absorption under pressure (AUL0.7 psi, method of measurement see below) of at least 18 g / g, preferably at least 20 g / g, preferably at least 22 g / g at least 23 g / g, most preferably at least 24 g / g and usually not more than 30 g / g.
  • AUL0.7 psi absorption under pressure
  • the superabsorbent according to the invention further has a saline flow conductivity (SFC measurement method s. Below) of at least 10x10 "7 cm 3 sec / g, preferably at least
  • a further subject of the present invention are hygiene articles containing superabsorbers according to the invention, preferably ultrathin diapers containing an absorbent layer consisting of 50 to 100 wt .-%, preferably 60 to 100 wt .-%, preferably 70 to 100 wt .-%, particularly preferably 80 to 100 wt .-%, most preferably 90 to 100 wt % of superabsorbent according to the invention, whereby the coating of the absorbent layer is, of course, not taken into consideration.
  • the superabsorbents according to the invention are also very particularly advantageous for the production of laminates and composite structures, as described, for example, in US 2003/0181115 and US 2004/0019342.
  • the superabsorbers according to the invention are also suitable for the production of completely analogous fibers described in US 2003/0181115 Structures using UV-crosslinkable hotmelt adhesives, which are sold, for example, as AC- Resin® (BASF SE, Carl-Bosch-Str. 38, 67056 Ludwigshafen, Germany).
  • UV-crosslinkable hot-melt adhesives have the advantage of being processable at as low as 120 to 140 ° C, so they are better compatible with many thermoplastic substrates. Another significant advantage is that UV-crosslinkable hot melt adhesives are toxicologically very harmless and also cause no exhalations in the toiletries.
  • a very important advantage, in connection with the superabsorbents according to the invention, is that the property of the UV-crosslinkable hotmelt adhesives does not tend to yellow during processing and crosslinking. This is particularly advantageous if ultrathin or partially transparent hygiene articles are to be produced. The combination of the superabsorbents according to the invention with UV-crosslinkable hotmelt adhesives is therefore particularly advantageous.
  • Suitable UV-crosslinkable hot-melt adhesives are described, for example, in EP 0 377 199 A2, EP 0 445 641 A1, US Pat. No. 5,026,806, EP 0 655 465 A1 and EP 0 377 191 A2.
  • the superabsorbent according to the invention can also be used in other fields of technology in which liquids, in particular water or aqueous solutions, are absorbed.
  • These areas are, for example, storage, packaging, transport (as constituents of packaging material for articles sensitive to water or moisture, for example for flower transport, also as protection against mechanical influences); Animal hygiene (in cat litter); Food packaging (transport of fish, fresh meat, absorption of water, blood in fresh fish or meat packaging); Medicine (wound plaster, water-absorbing material for burn dressings or for other weeping wounds), cosmetics (carrier material for pharmaceutical chemicals and medicaments, rheumatism plaster, ultrasound gel, cooling gel, cosmetic thickener, sunscreen); Thickener for oil / water or water / oil emulsions; Textiles (moisture regulation in textiles, shoe inserts, for evaporative cooling, for example in protective clothing, gloves, headbands); chemical-technical applications (as a catalyst for organic reactions, for the immobilization of large functional molecules such as enzymes, as adhesive
  • liquid absorption articles according to the invention differ from the known ones in that they contain the superabsorber according to the invention.
  • a process has also been found for the preparation of articles for the absorption of liquid, in particular hygiene articles, which is characterized in that at least one superabsorber according to the invention is used in the production of the article in question.
  • methods for producing such articles using superabsorbents are known.
  • Test Methods The superabsorbent is tested using the test methods described below.
  • the centrifuge retention capacity of the superabsorbent is determined according to the standard test method no. WSP 241.5-02 "Centrifuge retention capacity".
  • Absorption under pressure (AUL0.3psi, "Absorbency Under Load of 0.3 psi") The absorption under a pressure of 2068 Pa (0.3 psi) of the superabsorbent is determined according to the standard test method no. WSP 242.2-05 "Absorption under pressure”.
  • the absorption under a pressure of 4826 Pa (0.7 psi) of the superabsorbent is determined analogously to the standard test method no. WSP 242.2-05 "absorption under pressure", but with a weight of 49 g / cm 2 (leads to a pressure of 0.7 psi) instead of a weight of 21 g / cm 2 (leading to a pressure of 0.3 psi) is used.
  • Moisture content of the superabsorber residual moisture, water content
  • the water content of the superabsorbent particles is determined according to the standard test method no. WSP 230.2-05 "Moisture content”.
  • the mean particle size of the product fraction is determined according to the standard test method no. WSP 220.2-05 "particle size distribution".
  • DSM1 Medium German Collection of Microorganisms and Cell Cultures GmbH
  • 5.0 g / l peptone from meat (Merck KGaA; Darmstadt, DE, Art. No. 1 .07214)
  • 3.0 g / l meat extract Merck KGaA Darmstadt, Germany; Art. No. 1 103979
  • pH 7.0
  • Synthetic urine was prepared from 25 g / L urea (sterile-filtered), 9.0 g / L sodium chloride, 1 g / L peptone from meat and 1 g / L meat extract. The synthetic urine was autoclaved prior to adding the sterile-filtered concentrated urea solution.
  • 125 ml polypropylene histology beakers were autoclaved and the amount of superabsorbent particles necessary for the uptake of 50 ml of synthetic urine (calculated from the centrifuge retention capacity). Then, 50 ml of synthetic urine were inoculated with 50 ⁇ M bacterial solution corresponding to a total concentration of approximately 106 CFU / ml, mixed with the superabsorbent particles and immediately incubated with a diffusion test tube (Drägerwerk AG & Co. KGaA; Lübeck; DE; Dräger-Rschreibchen® Ammonia 20 / aD, Item No. 8101301). Hene cover screwed on. Ammonia evolution was monitored at 37 ° C for 48 hours.
  • the time of the first occurrence of ammonia on the test tube was recorded as the measured value.
  • the CRC of the product thus obtained was 30.9 g / g.
  • ammonia appeared for the first time after 21 hours.
  • Example 1 was repeated.
  • the CRC of the product thus obtained was 30.9 g / g.
  • Example 1 was repeated except that instead of the solution of 1,2-decanediol, 1.00 g of a previously prepared solution of 0.4148 g of 1,2-octanediol (from Alfa Aesar GmbH & Co KG, Zeppelin, Germany) were used. linstr. 7b, 76185 Düsseldorf, Germany, product number L08031, CAS 1 1 17-86-8) in 1, 9792 g of iso-propanol were added dropwise.
  • 1,2-decanediol 1.00 g of a previously prepared solution of 0.4148 g of 1,2-octanediol (from Alfa Aesar GmbH & Co KG, Zeppelin, Germany) were used. linstr. 7b, 76185 Düsseldorf, Germany, product number L08031, CAS 1 1 17-86-8) in 1, 9792 g of iso-propanol were added dropwise.
  • the CRC of the product thus obtained was 31.1 g / g.
  • ammonia first appeared after 10 hours.
  • Example 4 was repeated.
  • the CRC of the product thus obtained was 31.1 g / g.
  • Example 1 was repeated except that 30 g instead of 20 g of superabsorber were used and instead of the solution of 1, 2-decanediol 1, 5 g of a pre-prepared solution of 1 g of 1, 2-

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  • Veterinary Medicine (AREA)
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  • Epidemiology (AREA)
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  • Animal Behavior & Ethology (AREA)
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  • Biomedical Technology (AREA)
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  • Organic Chemistry (AREA)
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  • Chemical Kinetics & Catalysis (AREA)
  • Absorbent Articles And Supports Therefor (AREA)
  • Solid-Sorbent Or Filter-Aiding Compositions (AREA)
  • Compositions Of Macromolecular Compounds (AREA)
  • Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)
  • Processes Of Treating Macromolecular Substances (AREA)

Abstract

L'invention concerne des superabsorbants contenant du 1,2-décanediol, réduisant la formation d'odeurs.
EP13818685.3A 2012-12-20 2013-12-09 Superabsorbant inhibant les odeurs Withdrawn EP2934411A1 (fr)

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EP13818685.3A EP2934411A1 (fr) 2012-12-20 2013-12-09 Superabsorbant inhibant les odeurs

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TWI642713B (zh) 2017-03-31 2018-12-01 臺灣塑膠工業股份有限公司 吸水性樹脂及其製造方法
TWI625355B (zh) 2017-03-31 2018-06-01 臺灣塑膠工業股份有限公司 吸水性樹脂及其製造方法
CN107261186A (zh) * 2017-07-28 2017-10-20 威海洁瑞医用制品有限公司 抑制或吸收异味的水胶体材料和医用敷料及其制法
CN107280843A (zh) * 2017-07-28 2017-10-24 威海洁瑞医用制品有限公司 具有除味功能和极好适应性的造口底盘
JP7142430B2 (ja) * 2017-12-11 2022-09-27 株式会社リブドゥコーポレーション 吸収体およびこれを備えた吸収性物品
JP7439091B2 (ja) 2018-12-13 2024-02-27 ベーアーエスエフ・エスエー 臭気抑制組成物およびそれを組み込んだ衛生用品
TWI761904B (zh) 2020-08-10 2022-04-21 臺灣塑膠工業股份有限公司 吸水性樹脂及其製造方法

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US7247295B2 (en) 2001-06-22 2007-07-24 Dragoco Gerberding & Co. Ag Use of 1,2-decandiol for combating germs causing body odor
US20100069861A1 (en) 2008-09-18 2010-03-18 Min Yao Absorbent Articles Having Antimicrobial Properties And Methods of Manufacturing The Same
WO2010147868A2 (fr) 2009-06-15 2010-12-23 Gojo Industries, Inc. Compositions antimicrobiennes

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ES2220816T3 (es) * 2000-10-06 2004-12-16 THE PROCTER & GAMBLE COMPANY Articulos absorbentes que comprenden composiciones de mezcla de poliesteres biodegradables.
DE10249822A1 (de) * 2002-10-25 2004-05-13 Stockhausen Gmbh & Co. Kg Zweistufiges Mischverfahren zur Herstellung eines absorbierenden Polymers
EP1910460A1 (fr) * 2005-07-27 2008-04-16 Basf Se Compositions absorbant l'eau et inhibitrices des odeurs
CN101765435B (zh) * 2007-07-27 2013-05-22 巴斯夫欧洲公司 吸水性聚合物颗粒及其制备方法
JP2012514670A (ja) * 2009-01-09 2012-06-28 ビーエーエスエフ ソシエタス・ヨーロピア 匂いを抑制する吸水性ポリマー粒子の製造方法
US9717818B2 (en) * 2009-05-08 2017-08-01 Medline Industries, Inc. Absorbent articles having antimicrobial properties and methods of manufacturing the same
US9826736B2 (en) * 2010-08-12 2017-11-28 Professional Disposables International, Inc. Quaternary ammonium caprylyl glycol disinfectant wipes

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Publication number Priority date Publication date Assignee Title
US7247295B2 (en) 2001-06-22 2007-07-24 Dragoco Gerberding & Co. Ag Use of 1,2-decandiol for combating germs causing body odor
US20100069861A1 (en) 2008-09-18 2010-03-18 Min Yao Absorbent Articles Having Antimicrobial Properties And Methods of Manufacturing The Same
WO2010147868A2 (fr) 2009-06-15 2010-12-23 Gojo Industries, Inc. Compositions antimicrobiennes

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Title
See also references of WO2014095435A1

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CN104853705A (zh) 2015-08-19
WO2014095435A1 (fr) 2014-06-26
US20150306272A1 (en) 2015-10-29

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