EP1315545A2 - Utilisation de resines de polyisocyanate dans des couches filtrantes - Google Patents

Utilisation de resines de polyisocyanate dans des couches filtrantes

Info

Publication number
EP1315545A2
EP1315545A2 EP01978114A EP01978114A EP1315545A2 EP 1315545 A2 EP1315545 A2 EP 1315545A2 EP 01978114 A EP01978114 A EP 01978114A EP 01978114 A EP01978114 A EP 01978114A EP 1315545 A2 EP1315545 A2 EP 1315545A2
Authority
EP
European Patent Office
Prior art keywords
filter
polyisocyanate
weight
layer
cellulose
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Withdrawn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
EP01978114A
Other languages
German (de)
English (en)
Inventor
Gerhard Strohm
Rüdiger Leibnitz
Bernd Henne
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.)
Pall Corp
Original Assignee
Seitz Schenk Filtersystems GmbH
Pall Corp
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 Seitz Schenk Filtersystems GmbH, Pall Corp filed Critical Seitz Schenk Filtersystems GmbH
Publication of EP1315545A2 publication Critical patent/EP1315545A2/fr
Withdrawn legal-status Critical Current

Links

Classifications

    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
    • D21H27/00—Special paper not otherwise provided for, e.g. made by multi-step processes
    • D21H27/08—Filter paper
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D39/00—Filtering material for liquid or gaseous fluids
    • B01D39/14—Other self-supporting filtering material ; Other filtering material
    • B01D39/16—Other self-supporting filtering material ; Other filtering material of organic material, e.g. synthetic fibres
    • B01D39/1638—Other self-supporting filtering material ; Other filtering material of organic material, e.g. synthetic fibres the material being particulate
    • B01D39/1653—Other self-supporting filtering material ; Other filtering material of organic material, e.g. synthetic fibres the material being particulate of synthetic origin
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D39/00—Filtering material for liquid or gaseous fluids
    • B01D39/14—Other self-supporting filtering material ; Other filtering material
    • B01D39/16—Other self-supporting filtering material ; Other filtering material of organic material, e.g. synthetic fibres
    • B01D39/18—Other self-supporting filtering material ; Other filtering material of organic material, e.g. synthetic fibres the material being cellulose or derivatives thereof
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L1/00—Compositions of cellulose, modified cellulose or cellulose derivatives
    • C08L1/02—Cellulose; Modified cellulose
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
    • D21H17/00—Non-fibrous material added to the pulp, characterised by its constitution; Paper-impregnating material characterised by its constitution
    • D21H17/03—Non-macromolecular organic compounds
    • D21H17/05—Non-macromolecular organic compounds containing elements other than carbon and hydrogen only
    • D21H17/07—Nitrogen-containing compounds
    • D21H17/08—Isocyanates

Definitions

  • the invention relates to filters, in particular depth filters made of cellulose, which, despite being wet-strengthened, still have excellent swelling properties.
  • the invention relates to a method for their production and the use of such filters.
  • filters are used in addition to centrifuges in technical, especially large-scale processes.
  • Filters are often used for this purpose, which are made up of a felt or knitted fabric made of cellulose fibers. With such filters, the strength of these knitted fibers is not only generated by the entanglement of the individual fibers, but above all also by charge interactions, in particular hydrogen bonds, which hold the fibers together.
  • water molecules penetrate between the ionic groups, which leads both to a swelling of the cellulose structure and to a decrease in strength. The filter structure is also changed.
  • inhomogeneities e.g.
  • the swelling of the filter in the technical processes is particularly desirable because it contributes significantly to the sealing of the filter systems, but the decrease in strength and mechanical strength is extremely undesirable since it shortens the service life of a filter, ie it has to be replaced more frequently , which leads to equally frequent interruptions in the production process.
  • the aim is to produce filters with a good swelling capacity and at the same time sufficient wet strength.
  • it is particularly desirable to build up a very homogeneous filter structure in the filter layers in order to improve their filtration properties.
  • short cellulose fibers are pressed into one another, usually 0.6 - 1.3 mm long in the unground state and a fiber diameter of 15 - 20 ⁇ m, which are processed by fiber-shortening grinding at a low grinding degree and are glued together in the paper press under heat ,
  • Such processes are described, for example, in DE-A-42 11 480, WO 97/13033, EP-A-0, 582, 166 and WO 96/38629.
  • the aim of all these processes is to prevent adsorbable organic halogen (AOX) from entering the production wastewater and to prevent these substances from accumulating in the paper and in the cycle of the production water.
  • AOX adsorbable organic halogen
  • This type of gluing leads to a wet strength paper, whereby a product is already described as wet strength in the paper industry if its wet strength is at least 15% of the dry strength.
  • the measures usually used in the paper industry to increase strength such as pressing, adding gelatinizing starch derivatives or gluing the surface, are development of filter layers is excluded because these methods largely destroy the permeability and porosity of the filter layers.
  • DE 4223604 describes a process for the wet strengthening of molded parts or molding compounds made of cellulose, paper, straw or derivatives thereof by impregnation using a homogeneous organic polymer solution in which one or more water-insoluble polymers or polymer derivatives are dissolved, which may contain isocyanate groups or blocked isocyanate groups exhibit.
  • the polymers or their derivatives can also be dissolved in the oil phase of a water-in-oil emulsion.
  • the wet strength is achieved in that finished cellulose moldings or molding compounds are impregnated with the polymers by means of impregnation in such a way that that the entry of water into the fiber composite is completely prevented or at least drastically restricted.
  • Such a molded part which prevents the entry of water, is however not suitable for the filtration of aqueous solutions, since the liquid does not wet the hydrophobized layer and therefore cannot penetrate into the filter pores, which are usually in the micrometer and submicron range.
  • such molded parts have no swelling behavior and show no complete solidification of the entire body.
  • the object of the invention is now to provide filters which are equipped with a wet strength, the service life of which is considerably extended and which have a swelling behavior which is the same or only slightly less than that of the untreated product.
  • the object of the invention is to provide a filter which, despite an increased swelling behavior, also has a better filtering action than filters which are produced according to the prior art with other wet strength resins (for example polyamide-amine-epichlorohydrin resins, melamine-formaldehyde resins).
  • filters should be provided which have a significantly longer service life than the previously known wet-strength filters.
  • filters of this type should not bleed, ie they should not give up their wet-strength equipment in the filtered material.
  • the filter should remain stable even when used under elevated temperature conditions and maintain the properties mentioned above.
  • This goal is now achieved according to the invention in that the improved swellability is brought about by treating the cellulose fibers of the filter matrix with a polyisocyanate. This treatment takes place in particular before the formation of the filtration layer and expediently in suspension or a suspended mash.
  • Filters in particular depth filters, have a substantially higher basis weight of typically 200-3500 g / m 2 compared to paper. In addition, they often contain up to 70% by weight of inorganic filter-active substances.
  • the filters according to the invention usually contain 0.01-10% by weight, preferably 0.1-5% by weight and in particular 0.5-3% by weight of polyisocyanate, with amounts of only ⁇ 2% by weight of polymer or 0.05 - 2% by weight based on the layer mass is usually sufficient. In many cases, amounts of 0.1-1.2% by weight have proven to be expedient.
  • layer mass encompasses all the materials contained therein, such as cellulose, diatomaceous earth, perlite, etc. According to the invention, it was found that with these amounts the fibers are preferably provided with the polyisocyanate only at contact points where they touch and where they are glued to one another, the swelling capacity of the fiber network is maintained.
  • hydrophilic polyisocyanates are preferably used for this purpose, as described, for example, in WO 96/38629, WO97 / 13033 and EP-A-564 912.
  • the polyisocyanates are usually used in the form of emulsions (oil in water), as are generally known to the person skilled in the art and can be prepared from commercially available polyisocyanates.
  • Water-dispersible polyisocyanates or mixtures thereof are usually used in dilute form or added to the mash, normally in a concentration of up to 20% by weight, preferably up to 10% by weight in water, advantageously as finely divided dispersions with particle sizes of ⁇ 500 nm.
  • the concentration of the polyisocyanate resin can be freely selected in the mash in which the fibers are treated, as long as the desired bonding effect is achieved.
  • Quantities or concentrations of 0.0001% by weight to 0.5% by weight or from 0.00015% to 0.45% by weight of resin has been found to be useful. However, 0.0015% by weight to 0.23% by weight and in particular 0.0075% by weight to 0.14% by weight of resin are preferably used in the mash.
  • the concentration of the raw materials, ie fibers and any other solid auxiliaries present, is preferably 1.5% by weight to 4.5% by weight of solids in the suspension mash.
  • the cellulose filters according to the invention are largely (30-100% of the pulp content, preferably> 50%) made of long fibers with a length of> 2 mm, preferably 2-4 mm, in particular 2.5-4 mm and a fiber diameter of> 25 ⁇ m , preferably> 30 ⁇ m (in the unmilled state). They show long-term stability and are preferably fibrillatively ground in the processing process, high grinds of up to 80 ° SR being used in some cases.
  • the filters according to the invention preferably contain in their filter matrix additional filter components such as polysaccharides, cellulose derivatives such as cellulose acetate, agarose and their derivatives, dextrans and chitosans, as well as their derivatives and in particular inorganic particles such as natural silicate compounds such as diatomaceous earth, layered silicates, perlite, xerogels, feldspars, zeolites , Montmorillonite, molecular sieves and ion exchangers, activated carbon, titanium dioxide, zinc sulfide, calcium carbonate, talc as well as synthetic organic polymer particles, which can also consist in particular of the aforementioned reactive wet strength resins, polyvinylpyrrolidone (PVP or PVPP) and starch and starch derivatives such as oxidized and alkylated starches and synthetic fibers such as polyethylene, polypropylene.
  • the filters can contain up to 70% by weight based on the total content of the filter of these filter components.
  • the filter layers according to the invention have better filtration performance than other filter layers equipped with commercially available wet strength resins.
  • the filtration performance is largely characterized by the permeability and the clarifying effect of the filter layer and can be described quantitatively under defined filtration conditions.
  • the wetting behavior can be characterized by the resistance of the filter surface to the penetration of aqueous solutions, as indicated in Example 5.
  • the invention also relates to a method for producing such filter layers.
  • the cellulose fibers are treated with polyisocyanates before the filter layer is formed.
  • the cellulose fibers are suspended in a suspension medium and treated with one or more polyisocyanates in the suspended state.
  • Preferred suspending agents are aqueous suspending agents, but suspending agents can also be Onsstoff are used, which contain organic components, such as a water-in-oil emulsion or an oil-in-water emulsion.
  • the surface of the fibers or parts or point areas is preferably treated with the polyisocyanate.
  • the polyisocyanate can either be directly covalently crosslinked with functional groups lying on the surface of the fibers, or it can be adhesively bonded to the surface in a non-covalent manner. Such bonds are advantageously achieved by thermal treatment.
  • the suspended cellulose fibers treated in this way are then sedimented to form a layer, in particular an open-pore layer, which is usually done by removing the suspending agent, a filter matrix being formed in which the polyisocyanate is usually present in the matrix in a homogeneously distributed manner.
  • a common way of forming such filtration layers is to suck off the suspension medium on a support sieve.
  • the layer thus obtained is then dried at temperatures from 80 ° C., expediently at 80-200 ° C., preferably at 100-180 ° C. and in particular at 110-150 ° C. It has been shown according to the invention that the desired wet strength is obtained after drying, while maintaining the swelling effect, so that no further treatment is necessary.
  • depth filter layers with a basis weight of 200-300 g / m 2 , preferably 500-2000 g / m 2 and a wet strength of 20 N / 5 cm - 500 N / 5 cm, preferably 50-300 Make N / 5 cm.
  • the wet strength is determined as described in DIN 53112 part 2.
  • the force required to break or tear this sample is determined. This force is called the wet breaking force.
  • Samples with a free clamping length of 100 ⁇ 2 mm and a width of 50 mm are clamped in a tensile testing machine, which shows the measured force at the moment the sample breaks.
  • the test specimens are placed in a vessel in which they are completely immersed for 5 minutes.
  • the permanent wet strength is then determined in the same way, the layers being loaded differently instead of watering and then tested for wet strength in the tensile testing machine.
  • the filters according to the invention or the filters produced according to the invention can preferably be used for the production of foods and beverages, and in particular of beer and wine as well as of medicaments.
  • Cellulose fiber masses with commercially available wet strength agents namely melamine-formaldehyde resin [Madurit MW 167 (10% solution, Vianova Resins)], polyamidoamine-epichlorohydrin resin [Luresin KNU (BASF)], polyvinylamine [Baso-coll 8086 ( BASF)], polyethylene imine [Polymin P (BASF)], polyisocyanate [ISOVIN VP SP 42004 (Bayer)], CMC [Tylose C30 (Clariant)], silica sol [Klar-Sol-Super (Erbslöh)], polyacrylate [Acronal 27 D (BASF)] treated.
  • melamine-formaldehyde resin Melamine-formaldehyde resin
  • Polyamidoamine-epichlorohydrin resin Luresin KNU (BASF)]
  • polyvinylamine Baseo-coll 8086 ( BASF)]
  • polyethylene imine Polymin P
  • the wet solid resins and / or further additives in the form of aqueous suspensions or emulsions are added to a pulp pulp with stirring.
  • the filter layer is then formed on a laboratory sheet former, which can be used to simulate industrial filter layer production under idealized conditions.
  • the layers are formed by vertical dewatering of the fiber suspension through a sieve, supported by negative pressure.
  • the filling chamber of the sheet former is filled with water from below and filled with 2000 ml of a 2% pulp from above. After reaching the 4 liter mark, the water supply is switched off and the material suspension is mixed with compressed air for 5 s.
  • the suspension can then calm down for 5 s before the dewatering process is initiated by applying a negative pressure. After the liquid level has dropped through the nonwoven, air is sucked through the sheet for a further 10 s. Finally, the layer formed is dried at 130-150 ° C. The wet strength of the depth filters obtained in this way is determined after soaking in water for 5 minutes.
  • Test A The filters were then treated in accordance with the procedures described below as Test A to Test C in order to determine the permanent wet strength.
  • the filter layers in a layer filter were alternately charged with water vapor ten times at 1 bar pressure (10 5 Pa) for 30 minutes and then rinsed for 30 minutes with a 10% ethanol / water mixture at pH 3. It was then rinsed with a 2.5% sodium hydroxide solution (10 min., 500 l / m 2 h) and then the wet strength was determined on 5 cm wide and 15 cm long test specimens.
  • the respective filters were autoclaved at 121 ° C (0.1 MPa (1 bar) overpressure).
  • Diatomaceous earth-free cellulose filter mass pine sulfate, consistency: 3%, degree of grinding: 25 ° SR); Weight: 640 g / m 2 initial wet strength [1] and permanent wet strength [2] in N / 5 cm.
  • CMC carboxymethyl cellulose
  • test pressure lOOOmbar, test time 30 minutes
  • filtration behavior throughput and clarification effect
  • both filtration parameters can be described quantitatively [%] in a direct layer comparison by the value A.
  • the value A expresses the improved performance of the new filter layers made with a polyisocyanate compared to a layer made with a polyamidamine-epichlorohydrin resin.
  • formula A shows a 45% increase in performance of the filter layer produced with polyisocyanate. In this example, this results from a better clarification performance of the new polyisocyanate filter layer and at the same time increased permeability compared to the comparison layer.
  • the filters according to the invention also show superior filter performance on a modified model material suspension compared to Example 4a).
  • the Eura / Ovomaltine model fabric suspension was prepared as follows. 2.0 g of Ovomaltine, WASA GmbH, Celle and 7.0 g of coffee surrogate extract, from Günzburger Anlagenwerke, Günzburg are stirred into 1 1 of water and then made up to 100 1 with vigorous stirring (model suspension 2) and in aqueous suspension used for filtration tests in accordance with the 'investigation methods depth filter media filter layers' of the working group technology / analytics of the European professional association depth filtration eV (EFT).
  • EFT European professional association depth filtration eV
  • test pressure 1000 mbar
  • Test time 1800 s
  • the percentage differences (A values) document the improved performance of the new filter layers made with a polyisocyanate compared to a layer made with a polyamide-epichlorohydrin resin.
  • composition On a dried filter layer consisting of diatomaceous earth-free cellulose filter mass (pine sulfate, consistency: 3%, degree of grinding: 25 ° SR, mass per unit area: 640 g / m 2 , laboratory sheet), with approx. 3% residual moisture, 6 water drops are carefully pipetted with a pipette applied and the time required for the water drop to penetrate into the filter layer (average of 6 measurements) was measured (drop test).
  • diatomaceous earth-free cellulose filter mass pine sulfate, consistency: 3%, degree of grinding: 25 ° SR, mass per unit area: 640 g / m 2 , laboratory sheet
  • the assay characterizes the resistance of the filter surface to the penetration of ⁇ ssri- solutions.
  • the filter layers can thus be differentiated with regard to the wettability of the filter layer.
  • a drop of water is applied to the dried filter layers (moisture content: 3%) and the penetration time is measured (drop test).

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Health & Medical Sciences (AREA)
  • Medicinal Chemistry (AREA)
  • Polymers & Plastics (AREA)
  • Organic Chemistry (AREA)
  • Filtering Materials (AREA)
  • Chemical Or Physical Treatment Of Fibers (AREA)
  • Treatments For Attaching Organic Compounds To Fibrous Goods (AREA)
  • Separation Using Semi-Permeable Membranes (AREA)

Abstract

Filtre résistant à l'humidité, en particulier filtre à lit profond à haute capacité de gonflement, qui comporte une matrice de filtre contenant des fibres de cellulose et présentant des cavités à pores ouverts, les fibres de cellulose possédant sur leur surface du polyisocyanate chimiquement lié. Dans un mode de réalisation préféré de la présente invention, la matrice de filtre contient dans ses cavités des microparticules finement réparties. Un procédé de fabrication de ces filtres ainsi que leur utilisation dans l'industrie agro-alimentaire, des boissons et pharmaceutique est également décrit.
EP01978114A 2000-09-07 2001-09-06 Utilisation de resines de polyisocyanate dans des couches filtrantes Withdrawn EP1315545A2 (fr)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DE10044218A DE10044218A1 (de) 2000-09-07 2000-09-07 Einsatz von Polyisocyanatharzen in Filterschichten
DE10044218 2000-09-07
PCT/DE2001/003483 WO2002020635A2 (fr) 2000-09-07 2001-09-06 Utilisation de resines de polyisocyanate dans des couches filtrantes

Publications (1)

Publication Number Publication Date
EP1315545A2 true EP1315545A2 (fr) 2003-06-04

Family

ID=7655381

Family Applications (1)

Application Number Title Priority Date Filing Date
EP01978114A Withdrawn EP1315545A2 (fr) 2000-09-07 2001-09-06 Utilisation de resines de polyisocyanate dans des couches filtrantes

Country Status (6)

Country Link
US (1) US20040089601A1 (fr)
EP (1) EP1315545A2 (fr)
JP (1) JP2004508180A (fr)
AU (1) AU2002210350A1 (fr)
DE (1) DE10044218A1 (fr)
WO (1) WO2002020635A2 (fr)

Families Citing this family (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE10229291A1 (de) * 2002-06-29 2004-02-05 E. Begerow Gmbh & Co Filtermaterial, insbesondere in Form einer Tiefenfilterschicht
DE10331383A1 (de) * 2003-07-11 2005-02-10 E. Begerow Gmbh & Co Vorrichtung zum Filtrieren von Fluiden
DE10346256B3 (de) * 2003-09-24 2004-10-21 E. Begerow Gmbh & Co Verfahren zum Herstellen eines Filtermaterials
US20060102554A1 (en) * 2004-11-12 2006-05-18 Munirathna Padmanaban Process for producing film forming resins for photoresist compositions
DE102008037678A1 (de) 2008-08-14 2010-02-25 Sartorius Stedim Biotech Gmbh Tiefenfilterschicht mit anorganischem Schichtdoppelhydroxid
ES2369114T3 (es) * 2008-09-19 2011-11-25 Pall Corporation Material de lámina de filtro de profundidad y método para fabricar el mismo.
JP2011131452A (ja) * 2009-12-24 2011-07-07 Kao Corp ガスバリア性積層体の製造方法
JP5781321B2 (ja) * 2011-02-15 2015-09-16 旭化成せんい株式会社 蛋白質吸着性セルロース不織布
WO2015031899A1 (fr) * 2013-08-30 2015-03-05 Emd Millipore Corporation Milieu composite filtrant en profondeur à capacité élevé avec bas niveau d'extractibles
DE202016105559U1 (de) 2016-05-10 2016-12-09 Pure Flow Filtersysteme GmbH Filtermaterial und Filtrationsanordnung
CA3237785A1 (fr) 2017-03-31 2018-10-04 J.R. Simplot Company Poudres de proteine de pomme de terre

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Publication number Priority date Publication date Assignee Title
US3506480A (en) * 1969-02-24 1970-04-14 Gen Mills Inc Oil filter paper and process of preparing same
DE4119288B4 (de) * 1991-06-12 2004-08-26 Schenk-Filterbau Gmbh Verfahren zur Schichtenfiltration von pharmazeutischen, biologischen, chemischen oder dergleichen Flüssigkeiten
DE4223604A1 (de) * 1992-07-17 1994-01-20 Mueller Schulte Detlef Dr Verfahren zur Nassverfestigung von Cellulose, Papier, Papierderivaten sowie Formteilen oder Preßmassen derselben
DE4309845C2 (de) * 1993-03-26 1996-10-31 Seitz Filter Werke Filtermaterial und Verfahren zu seiner Herstellung

Non-Patent Citations (1)

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Title
See references of WO0220635A3 *

Also Published As

Publication number Publication date
AU2002210350A1 (en) 2002-03-22
WO2002020635A3 (fr) 2002-12-05
WO2002020635A2 (fr) 2002-03-14
JP2004508180A (ja) 2004-03-18
DE10044218A1 (de) 2002-04-04
US20040089601A1 (en) 2004-05-13

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