Classifications

• • D—TEXTILES; PAPER
  • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
  • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
  • D04H1/00—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres
  • D04H1/40—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties
  • D04H1/58—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties by applying, incorporating or activating chemical or thermoplastic bonding agents, e.g. adhesives
  • D04H1/587—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties by applying, incorporating or activating chemical or thermoplastic bonding agents, e.g. adhesives characterised by the bonding agents used
• • D—TEXTILES; PAPER
  • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
  • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
  • D04H1/00—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres
  • D04H1/40—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties
  • D04H1/42—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties characterised by the use of certain kinds of fibres insofar as this use has no preponderant influence on the consolidation of the fleece
  • D04H1/4326—Condensation or reaction polymers
  • D04H1/435—Polyesters
• • D—TEXTILES; PAPER
  • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
  • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
  • D04H1/00—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres
  • D04H1/40—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties
  • D04H1/58—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties by applying, incorporating or activating chemical or thermoplastic bonding agents, e.g. adhesives
  • D04H1/64—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties by applying, incorporating or activating chemical or thermoplastic bonding agents, e.g. adhesives the bonding agent being applied in wet state, e.g. chemical agents in dispersions or solutions
  • D04H1/645—Impregnation followed by a solidification process
• • D—TEXTILES; PAPER
  • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
  • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
  • D04H3/00—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length
  • D04H3/005—Synthetic yarns or filaments
  • D04H3/009—Condensation or reaction polymers
  • D04H3/011—Polyesters
• • D—TEXTILES; PAPER
  • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
  • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
  • D04H3/00—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length
  • D04H3/08—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length characterised by the method of strengthening or consolidating
  • D04H3/12—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length characterised by the method of strengthening or consolidating with filaments or yarns secured together by chemical or thermo-activatable bonding agents, e.g. adhesives, applied or incorporated in liquid or solid form
• • 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
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S260/00—Chemistry of carbon compounds
  • Y10S260/31—Ionic cross-link
• • 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
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S260/00—Chemistry of carbon compounds
  • Y10S260/43—Promoting degradability of polymers

Definitions

• the invention relates to a method for recovering fibers from nonwoven fabrics.
• Nonwovens can be consolidated by coating or impregnation with a binder.
• non-crosslinked binders were used for the consolidation of nonwovens, which are soluble in water by converting carboxyl groups into carboxylate groups and can thus be separated from the fibers again.
• binders are used which crosslink after application to the nonwoven fabric.
• the binders can be monomers with several ethylenically unsaturated groups or monomers with other reactive groups, e.g. Methylol groups.
• Crosslinking via metal salt groups, e.g. crosslinking via Ca carboxylate groups is e.g. known from EP 442 370. It is also desirable to recover fibers from nonwovens bonded with crosslinked binders.
• the object of the present invention was therefore a process for the recovery of fibers from nonwoven fabrics bonded or solidified with crosslinked binders.
• Nonwovens made from a wide variety of fibers can be used for the method according to the invention.
• synthetic fibers such as viscose, polyester, polyamide, polypropylene, polyacrylonitrile, carbon fibers or fibers of homo- and copolymers of vinyl chloride or tetrafluoroethylene or fibers of natural origin such as cellulose, cellulose, cellulose, cotton or wood fibers or also glass, ceramic or mineral fibers or mixtures thereof.
• the fibers are folded into non-woven fabrics and then solidified with a binding agent, for which purpose the binding agent e.g. is brought onto the fibers by impregnation, spraying, cracking, dipping or printing. This is generally followed by drying to remove the solvent, generally water. In this manner known to those skilled in the art, a bound, i.e. get consolidated nonwoven.
• a binding agent for which purpose the binding agent e.g. is brought onto the fibers by impregnation, spraying, cracking, dipping or printing. This is generally followed by drying to remove the solvent, generally water.
• nonwoven fabrics find e.g. Use as carrier materials for roofing membranes or floor coverings.
• binders polymers are generally used which are built up from ethylenically unsaturated monomers.
• the polymers contain carboxylate groups which are crosslinked via alkaline earth metal ions, i.e. they are cross-linked with metal salts.
• the polymers preferably contain 0.1 to 30 wt.%, Particularly preferably 0.5 to 25 wt.% And very particularly preferably 5 to 20 wt.
• the carboxylate groups are preferably 50 to 100%, particularly preferably 80 to 100%, as a salt with alkaline earth metal cations.
• Preferred alkaline earth metal cations are Ca 2+ and Ba 2+ , Mg 2+ .
• Ca 2+ is particularly preferred.
• the metal salt-crosslinked polymers can be obtained, for example, from polymers with carboxylic acid or carboxylic anhydride groups by adding an alkaline earth metal salt, for example an oxide, hydroxide, carbonate or hydrogen carbonate, for example for the aqueous dispersion or solution of the polymer, as described in EP-A-442 370.
• an alkaline earth metal salt for example an oxide, hydroxide, carbonate or hydrogen carbonate, for example for the aqueous dispersion or solution of the polymer, as described in EP-A-442 370.
• the metal salt-crosslinked polymer is preferably composed of the following monomers A), B) and C):
• Monomers A) are monomers with at least one carboxylic acid or carboxylic anhydride group, which can be converted into the metal salt groups. Particularly noteworthy are acrylic acid, methacrylic acid, itaconic acid, maleic acid, maleic anhydride.
• the amount of these monomers results from the desired content of carboxylate groups crosslinked with alkaline earth metal cations.
• Main monomers B) selected from C 1 -C 20 -alkyl (meth) acrylates, vinyl esters of carboxylic acids containing up to 20 C atoms, vinyl aromatics with up to 20 C atoms, ethylenically unsaturated nitriles, vinyl halides are of particular technical importance.
• Examples include (meth) acrylic acid alkyl esters with a C 1 -C 10 alkyl radical, such as methyl methacrylate, methyl acrylate, n-butyl acrylate, ethyl acrylate and 2-ethylhexyl acrylate.
• Vinyl esters of carboxylic acids with 1 to 20 C atoms are e.g. Vinyl laurate, stearate, vinyl propionate, vinyl versatic acid and vinyl acetate.
• Suitable vinyl aromatic compounds are vinyl toluene, ⁇ - and p-methylstyrene, ⁇ -butylstyrene, 4-n-butylstyrene, 4-n-decylstyrene and preferably styrene.
• nitriles are acrylonitrile and methacrylonitrile.
• the vinyl halides are chlorine, fluorine or bromine-substituted ethylenically unsaturated compounds, preferably vinyl chloride and vinylidene chloride.
• vinyl ethers examples include Vinyl methyl ether or vinyl isobutyl ether. Vinyl ethers of alcohols containing 1 to 4 carbon atoms are preferred.
• Butadiene, isoprene and chloroprene may be mentioned as hydrocarbons with 2 to 8 carbon atoms and two olefinic double bonds.
• monomers C for example monomers containing hydroxyl groups, in particular C 1 -C 10 -hydroxyalkyl (meth) acrylates or (meth) acrylamide, can be used in the polymer.
• Customary polymers generally consist of at least 40, preferably at least 60, particularly preferably at least 80% by weight of the above main monomers B).
• the polymerization can be carried out by conventional polymerization methods, e.g. by substance, emulsion, suspension, dispersion, precipitation and solution polymerization.
• the polymerization processes mentioned are preferably carried out in the absence of oxygen, preferably in a stream of nitrogen.
• the usual equipment is used for all polymerization methods, e.g. Stirred tanks, stirred tank cascades, autoclaves, tubular reactors and kneaders.
• the method of solution, emulsion, precipitation or suspension polymerization is preferably used.
• the methods of solution and, in particular, emulsion polymerization are particularly preferred.
• the polymerization can be carried out in solvents or diluents, e.g.
• the metal-crosslinked polymers are generally applied to the nonwovens in the form of their aqueous solution or dispersion. After drying, the nonwovens are bound, ie solidified.
• the non-woven fabrics then generally contain 1 to 40 parts by weight, preferably 5 to 30 parts by weight, of the metal-crosslinked binder, based on 100 parts by weight of fibers.
• the fibers can be recovered according to the method of the invention by removing the blinding agent from the nonwoven fabric, i.e. is separated from the fibers.
• the nonwoven fabric is treated with an aqueous solution of a salt (hereinafter referred to as "soluble salt"), the anion of which forms a salt which is poorly soluble in water with the alkaline earth metal.
• soluble salt a salt which is poorly soluble in water with the alkaline earth metal.
• the soluble salt can be an inorganic or organic salt.
• it is an alkali metal salt.
• the anion of the soluble salt can e.g. are oxalate or carbonate, which e.g. form a sparingly soluble salt with the calcium cation.
• the anion of the soluble salt can also be an organic anion, for example, which forms a poorly soluble complex with the alkaline earth metal, for example Ca 2+ .
• EDTA is particularly worth mentioning here.
• the soluble salt contained in the aqueous solution preferably has a solubility of at least 10 g / ⁇ l water at 23 ° C.
• the aqueous solution preferably contains the salt in amounts of 0.02 to 15 parts by weight, particularly preferably in amounts of 0.1 to 10 parts by weight, very particularly preferably 0.5 to 2.5 parts by weight , based on 100 parts by weight of water.
• solubility of the sparingly soluble alkaline earth metal salt formed when treating the nonwoven fabric is preferably less than 0.5 g / l of water at 23 ° C.
• the aqueous solution preferably also contains a phase transfer catalyst.
• phase transfer catalysts are, for example, in Chimia 34 (1980) No. 1, pages 12 to 20.
• phase transfer catalysts are, for example, polyalkylene glycols, which is commercially available, for example, under the name Pluriol® or quaternary, organic Ammonium salts, which are commercially available, for example, under the name lutensite.
• Quaternary organic ammonium salts include, in particular, those of the formula I. mentioned, wherein R 1 -R 4 independently of one another are an organic radical, preferably a hydrocarbon radical having 1 to 12 carbon atoms, preferably 1 to 6 carbon atoms and X ⁇ is an anion, preferably an inorganic anion, for example Cl - , Br ⁇ stands.
• phase transfer catalysts are those with alkoxy groups, preferably with 2 to 20 alkoxy groups, e.g. Alkylphenol ethoxylates (e.g. Lutensole® AP, emulsifier 825 fatty alcohol ethoxylates (e.g. Lutensol A8) and oxo alcohol ethoxylates (e.g. Lutensol AO7, Lutensol ON80).
• Alkylphenol ethoxylates e.g. Lutensole® AP
• emulsifier 825 fatty alcohol ethoxylates e.g. Lutensol A8
• oxo alcohol ethoxylates e.g. Lutensol AO7, Lutensol ON80
• phase transfer catalysts By alkoxylation of alkylphenols, fatty alcohols or oxoalcohols with alkylene oxides, preferably ethylene oxide, these phase transfer catalysts contain alkoxy groups.
• the content of the phase transfer catalyst in the aqueous solution is preferably 0.01 to 1 part by weight, particularly preferably 0.08 to 0.5 part by weight, based on 100 parts by weight of water.
• bases in particular sodium hydroxide solution, are also added in order to increase the proportion of alkali cations.
• the temperature of the aqueous solution can e.g. 10 to 100 ° C, in particular 15 to 80 ° C and particularly preferably 20 to 50 ° C. Temperatures above 30 ° C., in particular above 40 ° C., are advantageous in order to achieve an even better and, above all, faster detachment of the binder from the nonwoven fabric.
• the nonwoven fabric can be fed to the method according to the invention as a whole or in comminuted form.
• the nonwoven fabric is preferably chopped into parts with an edge length of 1 to 10 cm.
• the nonwoven fabric is preferably added to the aqueous solution.
• the amount of the nonwoven is preferably 1 to 200 g, particularly preferably 5 to 150 g and very particularly preferably 10 to 80 g per liter of solution.
• the treatment time can be shortened by intensive stirring. Generally, the time required is 5 minutes to 1 hour. With vigorous stirring, however, less than 30 minutes, in particular less than 20 minutes, are sufficient to detach at least 80% by weight of the binder from the fiber and to recover the fibers.
• Acronal® DS 2324x is an aqueous dispersion of a metal salt-crosslinked polymer (crosslinking of the carboxylate groups of the polymer with Ca 2+ cations) on an acrylate basis, the drying was carried out at 5 minutes at 200 ° C. in a Mathis laboratory dryer, after which the approximately A-4 sized fleece sheets were cut into pieces of about 1 cm 2 .
• a cold saturated sodium oxalate solution (approx. 3% by weight) and in each case a 10% by weight solution of soda or Na 4 EDTA (Trilon B) in water were prepared.
• the amounts of the phase transfer catalyst indicated in the table and optionally sodium hydroxide solution were added.
• the fleece pieces were stirred for about 24 hours using a laboratory stirrer for 15 minutes at 2000 rpm.
• the fibers were then filtered off through a 60 ⁇ sieve, dried at 130 ° C. for 2 h and weighed back.
• the degree of recycling is 100%. Values above 100% in the table can be explained by the fact that when the fibers were filtered off, very fine fibers were possibly not retained by the sieve and the weight of the fibers after recycling was too low.

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• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Dispersion Chemistry (AREA)
• Chemical Or Physical Treatment Of Fibers (AREA)
• Nonwoven Fabrics (AREA)
• Treatments For Attaching Organic Compounds To Fibrous Goods (AREA)

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• 1996
  • 1996-05-15 DE DE19619639A patent/DE19619639A1/de not_active Withdrawn
• 1997
  • 1997-05-06 US US08/852,064 patent/US6004428A/en not_active Expired - Fee Related
  • 1997-05-07 AT AT97107491T patent/ATE197323T1/de not_active IP Right Cessation
  • 1997-05-07 ES ES97107491T patent/ES2152593T3/es not_active Expired - Lifetime
  • 1997-05-07 EP EP97107491A patent/EP0807704B1/fr not_active Expired - Lifetime
  • 1997-05-07 DE DE59702552T patent/DE59702552D1/de not_active Expired - Fee Related

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