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
  • 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
  • D01F6/64—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from homopolycondensation products from polyesters from polycarbonates
• • 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
  • D01D5/04—Dry spinning methods
• • 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
  • Y10T428/2933—Coated or with bond, impregnation or core
  • Y10T428/2935—Discontinuous or tubular or cellular core
• • 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
  • Y10T428/2933—Coated or with bond, impregnation or core
  • Y10T428/2964—Artificial fiber or filament
• • 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
  • Y10T428/2973—Particular cross section
• • 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]
  • Y10T428/31507—Of polycarbonate

Definitions

• DT-OS 2 554 124 describes producing hydrophilic threads and fibers from thread-forming synthetic polymers by adding 5 to 50% by weight, based on solvent and solid, of a substance which is essentially a non-solvent for the polymer to the spinning solvent represents, which has a higher boiling point than the solvent used and which is well miscible with the spinning solvent and a liquid suitable as a washing liquid for the threads and then washes this non-solvent again from the threads produced.
• Preferred non-solvents in this process are polyhydric alcohols such as glycerin, sugar and glycols.
• Such fibers for example spun from acrylonitrile polymers, have and have a core-shell structure water retention of at least 10%.
• hydrophilic polycarbonate fibers e.g. the polycarbonate based on 4,4'-dihydroxydiphenyl-2,2-propane
• hydrophilic polycarbonate fibers with a core-shell structure and a water retention capacity of at least 10% are obtained under suitable spinning conditions, but their freezing temperature is greatly reduced and lies in usually at approx. 75 ° C, while pure polycarbonate fibers have a freezing temperature of 148 - 158 ° C (cf. B. v. Falkai, Lenzinger reports, episode 32, Dec. 1971, page 43).
• the invention therefore relates to dry-spun hydrophilic, core-sheath structure threads or fibers made of polycarbonates with a glass transition temperature of at least 125 ° C, a mercury density of at most 1.0 g / cm and a strength of at least 1.5 centinewtons / dtex.
• the invention further relates to a process for the production of these hydrophilic polycarbonate fibers after a dry spinning process, which is characterized in that at shaft temperatures of at most 140 ° C, the threads immediately after exiting the spinneret, but at the latest at a point in time when the thread consolidation has not yet been completed is in contact with a sufficient amount of water vapor.
• This spinning process is in principle a conventional dry spinning process, preferably from strongly polar organic solvents such as dimethylformamide, dimethylacetamide and dimethyl sulfoxide, which have a boiling point above 100 ° C.
• strongly polar organic solvents such as dimethylformamide, dimethylacetamide and dimethyl sulfoxide, which have a boiling point above 100 ° C.
• solvents e.g. Methylene chloride
• the width of the outer surface and the hydrophilicity and thus also the pore volume and the density of the threads can be controlled.
• the achievable hydrophilicity and the fiber density - in addition to the shaft temperature - also depends on the amount of water vapor used. In general, an increase in the hydrophilicity and a decrease in the fiber density is observed with increasing amount of steam (see Examples 2-5).
• the amount of water vapor required to achieve a desired hydrophilicity can therefore be easily determined.
• the minimum amount of water vapor blown in, which is required in a spinning process in a steam / air atmosphere at 30 m 3 / h in order to produce hydrophilic core sheath fibers with water retention capacity greater than 10%, is approximately 2 kg per 1 kg of spinning material.
• the steam is preferably blown in above the spinneret in the direction of the air flow and the thread take-off.
• hydrophilic polycarbonate threads Another important property of the hydrophilic polycarbonate threads is a sufficient strength of at least 1.5, preferably at least 2.2 centinewtons / dtex, in order to achieve good processability and usability.
• the usual stretching of approx. 1: 5 - 1: 6 over heating godets at temperatures above the freezing temperature at 180-220 ° C is not possible with the hydrophilic core sheath fibers made of polycarbonate according to the invention, because the porosity is lost at the high temperatures.
• boiling water only reaches a maximum stretch of 1: 2, which corresponds to a fiber strength of less than 1.5 centinewtons / dtex. With higher stretching, capillary cracks appear more.
• the degree of stretching can be increased to approximately 1: 3.5-1: 3.8 if the hydrophilic polycarbonate threads are stretched in water containing approximately 30% by weight D MF at 95-100 ° C. and residence times of a maximum of 2 seconds. With longer dwell times, the individual capillaries stick together. If the composition of the stretching bath liquid is changed, the maximum degree of stretching decreases again.
• the hydrophilic polycarbonate threads can only be stretched a maximum of 1: 2.7 times in 50% by weight DMF-containing water. With 40% by weight of DMF-containing water, the maximum degree of stretching increases to 1: 3.6 and in 30% by weight of DMF-containing water a further stretching by 1: 3.8 can be achieved.
• Double stretching is likewise advantageous in such a way that first a stretching in air is carried out immediately after leaving the threads of the shaft and then the described bath stretching. In this way, total stretching ratios above the maximum stretching ratio mentioned in the stretching bath, for example those of 1: 6, can be achieved.
• Hydrophilic polycarbonate fibers produced in this way have a strength of at least 1.5 centinewtons / dtex.
• Threads or fibers according to the method according to the invention have a matt, wadded appearance. They are particularly suitable as self-absorbent fleeces and tampons. Because of their resistance to cooking, they are preferred for hygiene articles.
• the Hg density (mean, apparent density) is determined by volume measurements in mercury at an overpressure of 10 bar.
• the helium density (“true density”) is determined by measuring the volume in helium with a gas comparison pycnometer.
• the water retention capacity is determined in accordance with DIN regulation 53 814 (cf. Melliand Textile Reports 4 (1973), page 350).
• the fiber samples are immersed in water containing 0.1% wetting agent for 2 hours. The fibers are then accelerated for 10 minutes at 10,000 m / sec 2 centrifuged and gravimetrically determined the amount of water that is retained in and between the fibers. To determine the dry weight, the fibers are dried to constant moisture at 105 ° C.
• Example 1 a The spinning solutions were spun as described in Example 1 a) to give core sheath fibers with a final titer of 3.3 dtex and aftertreated.
• the amount of steam and the shaft temperature were varied during the spinning process.
• the air volume was constant at 40 cbm / hour, the air temperature at 420 ° C and the spinning solution temperature at 125 ° C. With air volumes ⁇ 20 cbm / hour, air temperatures ⁇ 300 ° C and solution temperatures ⁇ 110 ° C, spinning was no longer possible (missing thread consolidation).
• the polymer described above was used as a solid in the weight ratios specified therein. Examples 6-9 (Comparative Examples)

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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)
• Multicomponent Fibers (AREA)
• Artificial Filaments (AREA)
• Spinning Methods And Devices For Manufacturing Artificial Fibers (AREA)

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• 1979
  • 1979-01-10 DE DE19792900703 patent/DE2900703A1/de not_active Withdrawn
  • 1979-12-20 US US06/105,822 patent/US4265971A/en not_active Expired - Lifetime
  • 1979-12-31 DE DE7979105408T patent/DE2961482D1/de not_active Expired
  • 1979-12-31 EP EP79105408A patent/EP0013764B1/fr not_active Expired
• 1980
  • 1980-01-09 JP JP62880A patent/JPS5593817A/ja active Pending

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