Classifications

• • 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
  • D01F9/00—Artificial filaments or the like of other substances; Manufacture thereof; Apparatus specially adapted for the manufacture of carbon filaments
  • D01F9/08—Artificial filaments or the like of other substances; Manufacture thereof; Apparatus specially adapted for the manufacture of carbon filaments of inorganic material
  • D01F9/12—Carbon filaments; Apparatus specially adapted for the manufacture thereof
  • D01F9/14—Carbon filaments; Apparatus specially adapted for the manufacture thereof by decomposition of organic filaments
  • D01F9/20—Carbon filaments; Apparatus specially adapted for the manufacture thereof by decomposition of organic filaments from polyaddition, polycondensation or polymerisation products
  • D01F9/21—Carbon filaments; Apparatus specially adapted for the manufacture thereof by decomposition of organic filaments from polyaddition, polycondensation or polymerisation products from macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
  • D01F9/22—Carbon filaments; Apparatus specially adapted for the manufacture thereof by decomposition of organic filaments from polyaddition, polycondensation or polymerisation products from macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds from polyacrylonitriles
• • 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
  • D01D5/08—Melt spinning methods
  • D01D5/098—Melt spinning methods with simultaneous stretching
• • 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
  • D01F6/28—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from copolymers obtained by reactions only involving carbon-to-carbon unsaturated bonds
  • D01F6/38—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from copolymers obtained by reactions only involving carbon-to-carbon unsaturated bonds comprising unsaturated nitriles as the major constituent
• • 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
  • D01D5/08—Melt spinning methods
• • 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
  • D01D5/08—Melt spinning methods
  • D01D5/088—Cooling filaments, threads or the like, leaving the spinnerettes

Definitions

• the present invention relates to a process for producing a multifilament yarn from a melt of a copolymer of polyacrylonitrile.
• the method is characterized in that a multifilament yarn is produced by pressing a melt of a copolymer through a spinneret and then stretched at least ten times.
• the present invention also relates to a correspondingly produced multifilament yarn.
• polyacrylonitrile (PAN) or copolymers of polyacrylonitrile are the dominant polymers as starting material for the production of precursor filament yarns (> 95%) and carbon fibers produced therefrom.
• the wide range of Ex-PAN carbon fibers is complemented by the ultra-high modulus pitch-based carbon fibers.
• acrylic precursor fibers have hitherto been produced exclusively by wet or dry spinning processes.
• a solution of the polymers with concentrations ⁇ 20% is spun either in a coagulation bath or a hot steam atmosphere, wherein the solvent diffuses out of the fiber.
• the costs of the methods are comparatively high. This results on the one hand from the required solvents and their handling, on the other hand from the relatively low throughput in solution spinning process.
• melt-spinnable copolymers of polyacrylonitrile have been successfully synthesized by copolymerization of acrylonitrile with an alkoxyalkyl acrylate and also continuously melt-formed into monofilaments.
• PAN polyacrylonitrile
• the titres of the monofilaments shown are> 1 tex.
• This filament titer is too high for conversion of the precursor, since the diffusion path for the occurring gaseous cleavage product from the filament, during the thermal treatment of the precursor to stabilize this and to carbonize, are too long.
• the invention thus relates to a process for producing a multifilament yarn in which a melt of a copolymer of polyacrylonitrile (PAN), preparable by a copolymerization of 95 to 60 mol% of acrylonitrile with at least one comonomer selected from a) 5 to 20 mol% of at least one alkoxyalkyl acrylate of the general formula I,
• PAN polyacrylonitrile
• Extrusion of a melt of the copolymer is spun through a plurality of spinning holes having spinneret to a multifilament yarn, and
• the multifilament yarn is stretched at least 10-fold.
• a melt of the aforementioned copolymer is pressed through a spinneret.
• the spinneret has a multiplicity of spinning holes, and when the melt of the copolymer is extruded through the spinneret, this results in one of the number of spinnerets.
• punch corresponding number of individual filaments The corresponding individual filaments are bundled into multifilament yarn. The multifilament yarn is then drawn.
• the multifilament yarn is stretched by at least 20 times, preferably by 25 to 1000 times, in particular 150 to 400 times.
• a further preferred embodiment of the method provides that the multifilament yarn is cooled before or during drawing.
• the cooling can be carried out in such a way that the multifilament yarn formed is supplied with gases, in particular air.
• the gas is preferably heated to temperatures of -50 to + 50 ° C, in particular to temperatures of 0 to 25 ° C.
• the stretching is preferably carried out at least 1.1 to 10 times, preferably 1.1 to 6 times, the length of the multifilament yarn before the stretching operation.
• Both stretching and stretching can take place by means of godets, in particular heated godets, in which case the temperatures of such godets are set to at least 50 ° C., preferably 50 to 150 ° C., in particular 55 to 90 ° C.
• the multifilament yarn is drawn from the spinneret with a nozzle delay of ⁇ 3000, preferably ⁇ 1500 to 10, particularly preferably ⁇ 500 to 30.
• This embodiment relates to the individual filaments from which the multifilament is formed.
• the distortion is directed to the respective individual filaments immediately after exiting the nozzle.
• Particularly advantageous in the present invention is that hiding the multifilament can be carried out such that a degree of orientation of the crystalline regions in the filaments forming the multifilament of> 0.7, preferably from 0.75 to 0.95, particularly preferably from 0 , 8 to 0.9 resulted.
• the mechanical strength of the multifilament yarn can be further increased. It is also possible that the spinneret to a temperature at least
• 10 K above the temperature of the melt of the copolymer is, preferably to a temperature of 10 to 80 K, in particular 15 to 45 K above the temperature of the melt of the copolymer is adjusted.
• the melt of the copolymer can be at a temperature of 120 to 300 ° C, preferably 150 to 230 ° C and / or a zero shear viscosity (determined by means of a rheometer HAAKE RS 150 with plate-cone (l °) arrangement with a diameter of the measuring geometries of 20 mm and a gap opening of 0.052 mm) of ⁇ 5000 Pa s, preferably 500 to 3000 Pa s, particularly preferably 1000 to 1500 Pa s are set.
• the individual filaments and / or the multifilament yarn formed from the individual filaments is cooled with a cooling medium, preferably a gaseous cooling medium, in particular air, nitrogen or argon, wherein the cooling medium preferably has a temperature which is at least 10 ° C below the Temperature of the melt of the copolymer is, with preferred temperatures in the range of 10 to 200, more preferably from 15 to 80 are.
• the multifilament yarn can be drawn off at a final take-off rate of at least 300 m / min, preferably at least 500 to 5000 m / min, in particular 750 to 2000 m / min.
• the final take-off speed refers to the speed with which the multifilament yarn is ultimately wound up on a roll.
• the multifilament yarn may be composed of 50 to 5,000 individual filaments 500 to 4000 individual filaments, in particular 1000 to 3000 individual filaments may be formed.
• the individual filaments on which the multifilament is based are preferably adjusted to a fineness of ⁇ 10 dtex, preferably from 0.01 to 10 dtex, particularly preferably from 0.1 to 5 dtex.
• the spinning holes may have a round, oval, Y-shaped, star-shaped or n-cornered with 8> n> 3 geometry and / or a length to diameter ratio of 1 to 20, preferably 2 to 8.
• the diameter of the spinnerets is preferably in the range of 10 to 1000 ⁇ , preferably 50 to 750 ⁇ , more preferably 100 to 500 ⁇ .
• the copolymer has a weight-average molar mass (Mw) in the range of 10,000 to 150,000 g / mol, preferably 15,000 to 80,000 g / mol.
• the copolymer has from 90 to 78 mole% of acrylonitrile
• the invention further relates to a multifilament yarn consisting of a plurality of individual filaments of a copolymer of polyacrylonitrile (PAN), preparable by a copolymerization of 95 to 80 mol% of acrylonitrile with at least one comonomer selected from a) 5 to 20 mol% of at least one alkoxyalkyl acrylate of the general formula I,
• PAN polyacrylonitrile
• a degree of orientation of the crystalline regions in the individual filaments of> 0.7, preferably from 0.75 to 0.95, particularly preferably from 0.8 to 0.9.
• a further preferred embodiment of the multifilament yarn according to the present invention provides that the individual filaments on which the multifilament yarn is based have a fineness of ⁇ 10 dtex, preferably from 0.01 to 10 dtex, particularly preferably from 0.1 to 5 dtex.
• the inventive method can be designed such that by means of a 1-screw extruder (L / D 25), the dried granules are successively melted, supplied to the gear pump, the constant volume flow of the melt through the spinneret promoted and the exiting filaments by means of a gas is cooled and stretched many times in the subsequent stretching unit by means of temperature-controllable godets to achieve Einzelfilamenttiter of ⁇ 3 dtex. It is completely dispensed with the addition of water or solvent.
• a 1-screw extruder L / D 25
• the dried granules are successively melted, supplied to the gear pump, the constant volume flow of the melt through the spinneret promoted and the exiting filaments by means of a gas is cooled and stretched many times in the subsequent stretching unit by means of temperature-controllable godets to achieve Einzelfilamenttiter of ⁇ 3 dtex. It is completely dispensed with the addition of water or solvent.
• the multifilament yarn according to the present invention can be produced in particular according to a further inventive method.
• the dried (vacuum 60 ° C./24 h) copolymer of PAN having a composition of 6.5 mol% of methoxyethyl acrylate and 93.5 mol% of acrylonitrile and an average molecular weight Mw of 43000 g / mol and a PDI of 1.3 was obtained in a 1-screw extruder (L / D 25) dosed. To avoid sticking, the feeder was cooled and then the temperature in the zones of the extruder increased from 150 ° C to 235 ° C.
• the produced melt of the PAN copolymer was constantly conveyed by means of a gear pump through a 32-hole spinneret with a round hole geometry, an L / D of 6 and a hole diameter of 300 ⁇ m. The exiting
• Filaments were cooled by means of an injection shaft and the nozzle delay of 98 realized by means of a withdrawal godet. On the downstream stretching godet, a degree of stretching of 1.6 could be realized before the produced multifilament yarn was continuously wound on a bobbin by a winding head.
• the single filament denier was 2.9 dtex and the filament had a tenacity of 20.3 cN / tex, an modulus of elasticity of 653 cN / tex and an elongation at break of 19.7% up.
• the degree of orientation of the crystalline phase determined by WAXS was 0.82.
• the dried (vacuum 60 ° C / 24 h) copolymer of PAN having a composition of 9.5 mol% of methoxyethyl acrylate and 90.5 mol% of acrylonitrile and an average molecular weight Mw of 55000 g / mol and a PDI of 1.2 was in a 1-screw extruder (L / D 25) dosed.
• the exiting filaments were cooled by means of an injection shaft and the nozzle delay of 82 realized by means of a take-off godet. On the downstream Reckgaletten could a max. Degree of stretching of 2.1 at a Galettentemperatur of 85 ° C before the produced multifilament yarn was wound by a winding head continuously at a speed of 1500 m / min on a spool.
• the filament has a circular cross-section and the single filament titer was 2.1 dtex and the filament had a tenacity of
• the dried (vacuum 60 ° C / 24 h) copolymer of PAN having a composition of 9.3 mol% of methoxyethyl acrylate and 90.7 mol% of acrylonitrile and an average molecular weight Mw of 85000 g / mol and a PDI of 1.2 was in a 1-screw extruder (L / D 25) dosed.
• the procedure was as in Example 1, the final spinning temperature was in contrast to Example 1 220
• the filament has a circular cross-section and the single filament denier was 1.6 dtex and the filament had a tenacity of 45.4 cN / tex, an modulus of elasticity of 920 cN / tex and an elongation at break of 11.8%.
• the degree of orientation of the crystalline phase determined by WAXS was 0.88.
• the coil-wound multifilament of PAN copolymer produced in Example 3 was exposed to a radiation dose of 300 kGy by means of electron beams. Unlike the non-electron beam treated sample of the multifilament yarn, the electron beam treated precursor yarn no longer exhibits melting up to a temperature of 400 ° C.
• the present invention will be described in detail with reference to the accompanying drawings.
• FIG. 1 shows an exemplary structure for carrying out a method according to the invention. With this structure, the multifilament yarns according to the invention can likewise be produced.
• a melt of the copolymer is extruded through a nozzle 1 having a plurality of nozzle holes.
• the emerging individual filaments are bundled to form a multifilament yarn.
• the resulting multifilament yarn is passed through a cooling channel 2 at a withdrawal speed v A via a
• an optional further preparation of the multifilament yarn can be made.
• the multifilament yarn with cooling air shown by arrows
• the stretching of the multifilament yarn can be adjusted.
• a stretching factor xi or x 2 can take place between the godets 4 and 5 or 5 and 6, respectively.
• the multifilament yarn is thus further stretched between the godets 4 and 5 and 5 and 6.
• the voltage applied to the multifilament yarn can be monitored by means of a voltage sensor 7.
• the obtained multifilament yarn is wound on a spool 8.

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• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Mechanical Engineering (AREA)
• Artificial Filaments (AREA)
• Spinning Methods And Devices For Manufacturing Artificial Fibers (AREA)
• Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)

Applications Claiming Priority (1)

Publications (1)

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• 2016
  • 2016-05-11 WO PCT/EP2016/060577 patent/WO2017194103A1/de unknown
  • 2016-05-11 EP EP16723074.7A patent/EP3455396A1/de active Pending
  • 2016-05-11 JP JP2018559393A patent/JP6802291B2/ja active Active
  • 2016-05-11 US US16/099,707 patent/US11649567B2/en active Active

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