Classifications

• • C—CHEMISTRY; METALLURGY
  • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
  • C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
  • C25B13/00—Diaphragms; Spacing elements
  • C25B13/04—Diaphragms; Spacing elements characterised by the material
  • C25B13/08—Diaphragms; Spacing elements characterised by the material based on organic materials
• • D—TEXTILES; PAPER
  • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
  • D01D—MECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS
  • D01D5/00—Formation of filaments, threads, or the like
  • D01D5/24—Formation of filaments, threads, or the like with a hollow structure; Spinnerette packs therefor
• • D—TEXTILES; PAPER
  • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
  • D01F—CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
  • D01F1/00—General methods for the manufacture of artificial filaments or the like
  • D01F1/02—Addition of substances to the spinning solution or to the melt
  • D01F1/10—Other agents for modifying properties
• • D—TEXTILES; PAPER
  • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
  • D01F—CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
  • D01F6/00—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof
  • D01F6/02—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from homopolymers obtained by reactions only involving carbon-to-carbon unsaturated bonds
  • D01F6/08—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from homopolymers obtained by reactions only involving carbon-to-carbon unsaturated bonds from polymers of halogenated hydrocarbons
  • D01F6/12—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from homopolymers obtained by reactions only involving carbon-to-carbon unsaturated bonds from polymers of halogenated hydrocarbons from polymers of fluorinated hydrocarbons
• • D—TEXTILES; PAPER
  • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
  • D01F—CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
  • D01F6/00—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof
  • D01F6/58—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from homopolycondensation products
  • D01F6/62—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from homopolycondensation products from 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
  • D04H1/42—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
  • D04H1/4209—Inorganic fibres
• • 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
  • D04H1/4282—Addition polymers
  • D04H1/4318—Fluorine series
• • 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
  • D04H1/4382—Stretched reticular film fibres; Composite fibres; Mixed fibres; Ultrafine fibres; Fibres for artificial leather
  • D04H1/43835—Mixed fibres, e.g. at least two chemically different fibres or fibre blends
• • 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
  • D04H1/60—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 dry state, e.g. thermo-activatable agents in solid or molten state, and heat being applied subsequently
• • 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
  • D04H11/00—Non-woven pile fabrics
• • 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
  • Y10S428/00—Stock material or miscellaneous articles
  • Y10S428/904—Artificial leather
• • 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
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/29—Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
  • Y10T428/2913—Rod, strand, filament or fiber
• • 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
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/31504—Composite [nonstructural laminate]
  • Y10T428/3154—Of fluorinated addition polymer from unsaturated monomers
• • 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
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/31504—Composite [nonstructural laminate]
  • Y10T428/3154—Of fluorinated addition polymer from unsaturated monomers
  • Y10T428/31544—Addition polymer is perhalogenated

Definitions

• the invention relates to a method for producing composite fibers and Diaphragms, such as those used in chlor-alkali electrolysis Find.
• the diaphragm process also has Production of caustic soda and chlorine from sodium chloride a large Meaning.
• an anode and cathode compartment separated by a porous diaphragm.
• An aqueous sodium chloride solution flows from the anode compartment through the diaphragm into the cathode compartment, where Hydrogen is generated on a steel cathode while a catholyte coexists contains sodium hydroxide and sodium chloride. That on the anode developed chlorine is obtained in gaseous form.
• Modern diaphragm cells work with adjustable, activated titanium anodes and with plastic fibers condensed diaphragms, which are increasingly being used instead of those previously used Asbestos diaphragms are inserted.
• the diaphragms consist of an organic framework Polymer fibers in which inorganic materials are incorporated.
• Various Process for the production of such diaphragms or for the production the composite materials used are known.
• EP-B-0 196 317 describes a process for the production of fiber composite materials described, in which a PTFE dispersion with zirconium dioxide and salt is mixed in a ball mill and heated, the Dispersant initially escapes. After mixing, the result is obtained Product separated from the balls used. It will be irregular Shaped, partially branched fibers obtained from a composite the PTFE used and the fine-particle zirconium dioxide.
• table salt serves as an aid for fiber formation and can be released by the brine before or during subsequent use become.
• a diaphragm can then be made from the fibers obtained getting produced.
• the diaphragms obtained by the known methods do not always show the desired high flow resistance, the one Back mixing of the sodium hydroxide solution obtained in the electrolysis prevented. The diaphragms obtained are therefore not suitable for all applications sufficient quality.
• the flow resistance of the diaphragms determines the flow of brine through the diaphragm.
• the flow also depends on the pressure with which the brine is pressed through the diaphragm.
• the pressure is regulated by the difference in level between the incoming brine and the outgoing catholyte. Suitable values are, for example, between 20 and 70 cm liquid column.
• This flow in turn has a direct effect on the concentration of the lye produced.
• the optimal flow depends on the current density applied.
• the concentration of the lye obtained should be in the range from 100 to 150 g / l. In practice, for example, flow rates of 20-30 l / m 2 h and current densities of 2 to 2.5 kA / m 2 are used .
• the object of the present invention is to provide a method for Production of such composite fibers, which is the production of diaphragms allow with a defined flow resistance, so that the technical Requirements in a chlor-alkali electrolysis cell are met.
• the heating in step (b) is at a temperature of more than 70 ° C, particularly preferably more than 100 ° C, in particular 130-180 ° C carried out. Coarse, strong clumps of fiber are already formed.
• the cooling in step (c) and the shearing in step (d) take place preferably at a temperature in the range of 20-60 ° C. At work at a lower temperature in step (d) the mixing and shearing difficult due to the higher rigidity of the material. In this step the material is shredded and separated too freely flowing fibers.
• step (d) advantageous in mixers with a Froude number of more than 1 is carried out.
• mixers must be used in this step, that have a Froude number of more than 1.
• the Cooling in step (c) or (d) are dispensed with.
• the frequency is determined from the speed of the mixing tools. The radius is the greatest distance between the mixing tool and the shaft.
• Suitable mixers are Eirich mixers, ring trough mixers, ring layer mixers, DRAIS mixer. Also the use of a Lödige mixer, which is equipped with additional chopper, resulting in Froude numbers of more than 1 can be achieved.
• an Eirich mixer is used as the intensive mixer, which characterizes it is that it has a rotating mixing tank and either the same or counter-rotating mixing tool (swirler). The mixing tool can reach a very high speed of more than 2000 rpm.
• Both Mixing tools are whisk or stirrer-like Tools that can have diverse geometric shapes and for one good mixing and the entry of a high mixing energy. By a wall scraper prevents material from sticking to the wall.
• Eirich intensive mixers are from the Gustav Eirich machine factory in Hardheim, Germany available.
• the method can preferably also be carried out in a heatable vacuum mixer be performed.
• vacuum mixers e.g. by Eirich. These mixers work according to the so-called EVACTHERM® process (from Eirich).
• the mixing material is heated in these mixers with steam or with Superheated steam that is directed directly to the mix and through the Jacket heating of the mixer.
• the temperature of the jacket, also with Steam is heated, can be controlled via pressure or negative pressure.
• a particular advantage of these mixers is the possibility of rapid cooling of the content. By injecting water and then evacuating the mixer contents to the desired temperature ( ⁇ 70 ° C) are cooled.
• the invention also relates to the use of such mixers with a Froude number of more than 1 in the manufacture of composite fibers.
• the process according to the invention gives fibers which are dry and are free flowing. This is done particularly by using the intensive mixers reached in step (d).
• the above are particularly preferred Intensive mixer also used in step (b) of the method according to the invention.
• all steps of the method according to the invention are described in the same intensive mixer performed so that a transfer during the The procedure does not apply.
• the fibers obtained, which are dry and free flowing, can be easily removed from the mixer. In contrast to ball mills there is also no need to separate the balls from the fibers.
• the PTFE or PTFE copolymer dispersion in step (a) is preferred used as an aqueous dispersion.
• the dispersant preferably water, and fiber formation initiated by the shear.
• the fibers are finished by crushing, whereby the free-flowing fiber material according to the invention is obtained.
• alkali or alkaline earth salt is preferably used as the fiber-forming material used. These are preferably alkali or alkaline earth halides. Table salt (sodium chloride), magnesium chloride, Calcium chloride or sodium carbonate, especially sodium chloride used.
• the particle size should preferably be 90% (based on the weight) less than 300 ⁇ m, preferably less than 200 ⁇ m, particularly preferably be less than 100 microns. A typical preferred particle size distribution is as follows: 10% ⁇ 5 ⁇ m, 50% ⁇ 40 ⁇ m, 90% ⁇ 80 ⁇ m.
• the PTFE or PTFE copolymer dispersion is made by dispersing PTFE or PTFE copolymer, preferably in water, using a dispersant, especially a non-ionic surfactant in one Amount of 1-10 wt .-%, based on the PTFE or PTFE copolymer used.
• Preferred dispersions are made by emulsion polymerization.
• the solids content is preferably 30 to 80%, particularly preferably 50 up to 70%.
• the viscosity of the dispersion is at a shear rate of 4000 / s preferably 7 to 13 mPas.
• the particle size is preferably 100 to 500 nm, particularly preferably 150 to 300 nm.
• PTFE or PTFE copolymer powders which can be used according to the invention preferably have bulk densities of 300 to 1000 kg / m 3 , particularly preferably 400 to 600 kg / m 3 .
• the average particle size is preferably 20 to 1000 ⁇ m, particularly preferably 250 to 700 ⁇ m.
• the powders are preferably free-flowing, in particular powders with an average particle diameter of approximately 500 ⁇ m and a bulk density of approximately 500 kg / m 3 .
• the PTFE or PTFE copolymer powders can be dispersed in a dispersant before use.
• the solids content of the PTFE dispersion used can sometimes be advantageous still decrease by adding water to a desired one Adjust concentration.
• a prediction of which amounts of water make sense is not possible, but should be adjusted in individual cases (e.g. 2-30%, more specifically 5 - 10% when using an approx. 60% dispersion).
• the PTFE or PTFE copolymer powders can also be used without being previously dispersed in a dispersant. This has the Advantage that no dispersant has to be removed. It is preferred However, powders still contain a surfactant in an amount of 1 - 15% added to the PTFE weight.
• the addition of the surfactant can be done before or after mixing the components in process step (a), in any case before heating up [process step (b)].
• surfactants nonionic surfactants are preferred.
• Modified PTFE grades can also be used as PTFE.
• PTFE which contains small amounts of suitable comonomers contains.
• Comonomers can be: hexafluoropropylene, perfluoro (propyl vinyl ether), Ethylene, chlorotrifluoroethylene, vinylidene fluoride.
• perfluorinated comonomers are used.
• Modified PTFE powders are e.g. by Dyneon under the designation Hostaflon® TFM offered. They contain ⁇ 1% of a comonomer.
• PTFE copolymers can also contain larger amounts of comonomers, e.g. 7-8 mol%.
• comonomers e.g. 7-8 mol%.
• FEP hexafluoropropylene
• PFA Perfluoropropyl vinyl ether
• the weight ratio of PTFE or PTFE copolymer to fine particles inorganic material, without fiber-forming material is preferably 0.2 to 0.6; particularly preferably 0.25 to 0.5; in particular 0.28 to 0.43.
• the vortex speed is then set to a suitable value (e.g. 450 rpm), or you switch off the swirler and leave the mixing tank rotate at low speeds of preferably a maximum of 100 rpm and heats the mixture to the desired temperature.
• a suitable value e.g. 450 rpm
• the temperature range the fiber formation depends on the material used. Usually the temperature is more than 70 ° C and is for example in the range of 80-200 ° C.
• that contained in the dispersion Water removed so that at temperatures below 100 ° C with reduced Pressure should be worked. Even at higher temperatures Worked under reduced pressure to remove the water or to accelerate the dispersant.
• the heating time is preferably 0.25 to 2 hours. It hangs on the construction and size of the mixer and the type of heating and can be more than 2 hours with lower heating output. In the In practice, values of up to 6 hours are not critical. For example, it can wall heating or by introducing hot steam (superheated steam) be heated.
• the mixer contents are allowed to cool down again. This happens on easiest by letting it stand, that is, without further mixing. During the cooling process, however, it is also possible to continue mixing or to a coolant such as cold air or water is blown faster to cool down be injected and subsequently evacuated.
• a coolant such as cold air or water is blown faster to cool down be injected and subsequently evacuated.
• the speed of the swirler is preferably set to a value in the range set from 300 to 2500 rpm.
• the mixing time is preferably 10 seconds up to 60 min. The speed and the time of mixing depend on the desired degree of shredding. As a rule, mixing times range from 1 to 1.5 min at a speed of 2500 rpm or 1 to 5 min at a Speed from 450 rpm.
• the free-falling fiber material can then be discharged in a simple manner become.
• the composite fibers obtained are dry, free-flowing, finely divided material.
• the fibers are fibril-like, anisotropic and of irregular morphology. The color depends on the used inorganic material and the PTFE or PTFE copolymer polymer. Each single fiber can be branched or not branched.
• the inorganic Material is evenly distributed over the entire fiber and intimate with the PTFE or PTFE copolymer mixed as a polymeric binder so that it cannot be separated without destroying the fiber. Also located finely divided inorganic material on the surface of the fiber.
• the composite fibers that can be produced or produced according to the invention are for Manufacture of diaphragms, especially for chlor-alkali electrolysis, usable.
• the diaphragms can be produced as described in EP-B 0 196317 respectively.
• a cathode for example, can be used as the porous support can be used, which has the shape of a grid and with a polyamide network is covered.
• the weighed components are stirred for 15 minutes using a magnetic stirrer 900-1000 1 / min stirred.
• the diaphragm is filled with a 4% solution of zonyl for 12 hours Treated FSN® (a fluorosurfactant from DuPont) and then 12h at 70-80 ° C dried.
• Treated FSN® a fluorosurfactant from DuPont
• test diaphragms are a flow measurement with brine solution (300g / l NaCl), at room temperature and a constant liquid column of 22 cm subjected.
• Example 2 The procedure according to Example 1 was repeated, but after mixing at Room temperature for 10 min within 60 min without switching on the swirler was heated to a temperature of 92 ° C. Then the swirler became switched on at a speed of 450 rpm and under for 10 min Heating up to 109 ° C.
• the swirler is used in the following Steps not turned off, but still at a speed of 450 rpm operated. After reaching a temperature of 109 ° C to 40 ° C cooled and then again within 15 min to a temperature of Heated up to 160 ° C. It is then cooled to a temperature of 62 ° C and crushed.
• Functional diaphragms can be obtained from the fibers obtained become. It is possible to make fibers that are too small by grinding too long have been reprocessed by heating up again. The fiber formation starts again in the heat treatment, so that usable fibers can be obtained.
• a fiber mash is now produced according to Example 4, for which purpose 1736 g of the solution described in Example 4 and 250 g of fibers are used.
• An apparatus is immersed in this fiber suspension, which is equipped with a round piece of cathode grid, which has an area of 78.5 cm 2 .
• the dispersed fibers are sucked onto the grid until no further fibers can be sucked up and after the diaphragm has been removed from the fiber bath, the vacuum remains at a pressure of 50-150 mbar.
• the diaphragm After drying and thermal treatment of the diaphragm according to Example 4, the diaphragm had a weight of 35 g. This corresponds to a sheet weight of approx.4.5 kg / m 2 . The diaphragm was then hydrophilized for 24 hours with a 4% zonyl solution. In the subsequent measurement of the flow, a flow rate of 20-25 l / h * m 2 was found.
• An electrolytic cell for chlor-alkali electrolysis with 7 dm 2 of electrode area was (dm 7 2) using the same fibers of several approaches in an analogous manner with a diaphragm equipped.
• a box-shaped storage apparatus with the cathode grid (7 dm 2 ) was immersed in a correspondingly produced fiber bath (from 43.4 kg of mash solution according to Example 4 and 6.25 kg of fibers) and that by applying vacuum to the back of the cathode grid Diaphragm sucked up.
• the cathode construction coated with the diaphragm was dried and subjected to a thermal treatment in accordance with Example 4. After baking (sintering) and hydrophilizing the diaphragm, the electrolytic cell was assembled and operated for 5 weeks with the following values:

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• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Electrochemistry (AREA)
• Organic Chemistry (AREA)
• Metallurgy (AREA)
• Manufacturing & Machinery (AREA)
• Materials Engineering (AREA)
• Mechanical Engineering (AREA)
• Inorganic Chemistry (AREA)
• Chemical Or Physical Treatment Of Fibers (AREA)
• Compositions Of Macromolecular Compounds (AREA)
• Reinforced Plastic Materials (AREA)

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• 1997
  • 1997-10-21 DE DE19746404A patent/DE19746404A1/de not_active Withdrawn
• 1998
  • 1998-10-20 NO NO984888A patent/NO984888L/no not_active Application Discontinuation
  • 1998-10-21 CN CN98122618A patent/CN1090252C/zh not_active Expired - Fee Related
  • 1998-10-21 US US09/176,151 patent/US6352660B1/en not_active Expired - Fee Related
  • 1998-10-21 EP EP98119738A patent/EP0911432A3/fr not_active Withdrawn
  • 1998-10-21 PL PL98329304A patent/PL329304A1/pl unknown

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