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
  • D01F6/60—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from homopolycondensation products from polyamides
• • 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
  • D01F11/00—Chemical after-treatment of artificial filaments or the like during manufacture
  • D01F11/04—Chemical after-treatment of artificial filaments or the like during manufacture of synthetic polymers
  • D01F11/08—Chemical after-treatment of artificial filaments or the like during manufacture of synthetic polymers of macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds

Definitions

• the invention relates to a process for the production of particularly high molecular weight polyamide fibers and polyamide fibers produced by this process.
• the so-called technical polyamide fibers are used, among other things. used for netting and cordage, conveyor belt fabrics, industrial machine felts, filters, fishing wires, technical fabrics and guy wires as well as bristles. Since aliphatic polyamides generally have good chemical resistance, they are ideal for paper machine clothing. In addition to general good mechanical properties, such as high tensile strength, high requirements especially for properties that are subject to a bending process, e.g. Flexural strength and abrasion resistance. The latter are heavily dependent on the molecular weight of the polymer. The higher the degree of polymerization of the polymer, the more resistant the fibers are to bending stress.
• the polyamide granules are subjected to a solid-phase condensation, e.g. in US-PS 3 420 804 or in EP-PS 0 098 616.
• the disadvantage of this procedure is that the high molecular weight granulate has a very high melt viscosity and is therefore difficult to spin due to the high pressure build-up in front of the spinneret plate.
• uncontrolled molecular weight degradation occurs in the melt of high molecular weight granules during the spinning process.
• CH-PS 0 359 286 describes a process for the production of high molecular weight polyamide granules according to the post-condensation principle in two steps.
• the post-condensation catalysts are incorporated into the melt of the polyamide starting material and the post-condensation of the plastic parts obtained by injection molding or extrusion molding is then post-condensed. This procedure is unsuitable for the production of high molecular weight polyamide fibers because the incorporated catalysts trigger the post-condensation in an uncontrolled manner even in the hot polyamide spinning melt.
• Japanese Laid-Open Specification 27 719/76 describes the post-condensation of molded polyamide molded parts immersed in catalyst solution in order to increase the service life of molded parts subject to high stress by converting the two-dimensional molecular structure into a three-dimensional, i.e. by crosslinking the polyamide on the surface.
• Superficially cross-linked fibers are, however, severely disadvantaged in terms of staining and permanent bending stress.
• Japanese design specification 27 719/76 does not name fibers, but molded parts such as ring travelers and sliding rollers.
• the invention is therefore based on the object of producing particularly high molecular weight and uncrosslinked polyamide fibers with high flexural strength and good abrasion resistance.
• the invention provides a process for the post-condensation of melt-spun polyamide fibers in the solid phase in the presence of post-condensation catalysts, as well as the fibers produced by this process.
• polyamide fibers can be post-condensed in the solid phase without crosslinking and thus without showing the disadvantageous properties to be expected from their use.
• Normally viscous polyamide fibers are those with relative solution viscosities in H2SO4 of at most 4.2, preferably up to 4.0, particularly preferably those in the viscosity ranges around 3.4 and 3.8, particularly preferably around 3.8. They are made from ⁇ -aminocarboxylic acids or lactams with 4 to 12 carbon atoms or mixtures thereof, but preferably PA-4, PA-6, PA-11 and PA-12, or from aliphatic diamines with 4 to 12 carbon atoms and aliphatic dicarboxylic acids with 5 up to 12 carbon atoms or from their mixtures, but preferably PA-4.6, PA-6.6, PA-6.10 and PA-12.12.
• inorganic phosphorus compounds preferably salts or esters of phosphorous acid or orthophosphoric acid or these acids themselves are used, but particularly preferably H3PO4, H3PO3, Na2HPO4.12H2O, Na2HPO3.5H2O and NaH2PO4.
• the normally viscous polyamide fibers are made in a known manner, e.g. impregnated in a liquor, the catalyst content, based on the fibers to be condensed, being at most 0.5% by weight, preferably 0.1 to 0.3% by weight, particularly preferably 0.2% by weight.
• the post-condensation is carried out at temperatures of 160 to 200 ° C., preferably 170 to 190 ° C., in an inert gas atmosphere or in vacuo for 5 to 48 hours, preferably 6 to 24 hours, particularly preferably 8 to 12 hours.
• All polyamide types contain commercially available heat stabilizers from Ciba-Geigy / Switzerland of the Irganox type, with the exception of Grilon TM 26 highly viscous.
• the relative solution viscosities are measured as a 1% solution in 98% sulfuric acid according to DIN 53727 at 20 ° C.
• 17 dtex-PA-6 fibers of the Grilon TM 26 R type with 11 sheets per cm and relative solution viscosities of 3.36 are thermally post-condensed at 180 ° C. in vacuo during the times indicated in Table 1 without a catalyst.
• the amount of acid used is 0.2% by weight, based on the fibers to be condensed. After filtration and air drying, the mixture is post-condensed in a vacuum at 170 ° C. for 8 hours.

Landscapes

• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Artificial Filaments (AREA)
• Polyamides (AREA)
• Chemical Or Physical Treatment Of Fibers (AREA)

Applications Claiming Priority (2)

Publications (2)

Family

ID=6413011

Family Applications (1)

Country Status (8)

Cited By (2)

Families Citing this family (13)

Family Cites Families (7)

• 1990
  • 1990-08-27 DE DE4027063A patent/DE4027063C2/de not_active Expired - Fee Related
• 1991
  • 1991-08-02 CA CA002048373A patent/CA2048373C/fr not_active Expired - Fee Related
  • 1991-08-20 JP JP3207780A patent/JPH05156568A/ja active Pending
  • 1991-08-21 ES ES199191113961T patent/ES2033226T1/es active Pending
  • 1991-08-21 EP EP19910113961 patent/EP0474027A3/de not_active Withdrawn
  • 1991-08-26 FI FI914011A patent/FI914011L/fi unknown
  • 1991-08-27 KR KR1019910014834A patent/KR920004621A/ko not_active Withdrawn
  • 1991-08-27 US US07/750,831 patent/US5234644A/en not_active Expired - Fee Related

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