Classifications

• • D—TEXTILES; PAPER
  • D02—YARNS; MECHANICAL FINISHING OF YARNS OR ROPES; WARPING OR BEAMING
  • D02J—FINISHING OR DRESSING OF FILAMENTS, YARNS, THREADS, CORDS, ROPES OR THE LIKE
  • D02J1/00—Modifying the structure or properties resulting from a particular structure; Modifying, retaining, or restoring the physical form or cross-sectional shape, e.g. by use of dies or squeeze rollers
  • D02J1/22—Stretching or tensioning, shrinking or relaxing, e.g. by use of overfeed and underfeed apparatus, or preventing stretch
  • D02J1/221—Preliminary treatments
• • 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
  • D01F6/58—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

Definitions

• the invention relates to the improvement of the heat stability characteristics of polyamides.
• a mixture of, e.g., a copper compound with alkali iodides in the required concentration can be dusted on the extracted chip prior to spinning. While good heat stability thus is attained, the distribution of the stabilizers in the polyamides is not uniform. This leads to a considerable decrease in their strength characteristics, particularly when fibers, bristles and foils are produced. The reason for this drawback is that the stabilize components cannot be applied uniformly even when dusted. This is especially true in the presence of inorganic halogen compounds. Moreover, insoluble precipitates form in the melt, upon addition of the stabilizers to the polyamide forming starting products. Upon spinning, using either method of stabilizer addition, the stabilizer components precipitate at the outer edge of the spinning nozzles.
• the second components are added to the spinning preparations of the fibers or the like. This permits the stabilizers to penetrate into the interior of the freshly spun fiber since the spinning preparation is applied to the dry and absorptive amorphous filament. This can be accomplished, e.g., by leading the filament through two rollers. It also is feasible to add the second component with other additives, such as light stabilizers, optical bleaches, and the like. This latter procedure has the added advantage that no special operational step is required and hence saves expenses.
• the process according to the invention as compared with processes wherein application occurs after stretching, also effects a wash-resistant fixing of the second component on the fiber because the stretching operation following spinning leads to a compaction and orientation of the fiber structure whereby, due to the occurring crystallization, the initially porous structure is closed and the accessibility of solubilizing agent to the inner regions of the fibers is substantially decreased after stretching.
• the ingredients of the second components of the stabilizer combination are of mutually poor compatibility, i.e., when the different compounds together yield insoluble precipitates or when the storage life of the solution or emulsion is insufiicient, the two incompatible ingredients can be applied using two different sets of rollers.
• the second components of the stabilizer combination are applied as an aqueous solution or in an organic solvent, to the spinning fiber on the first roller set.
• additional second component may be applied by means of a second roller set. This enables an application in several layers, and incompatible ingredients which, however, are soluble in water or organic solvents, can be applied.
• the stabilizer component solely on the surface of the fiber by using the first roller set for the spinning preparation alone with the second roller set applying the stabilizer.
• the stabilizer acts only on the surface of the fiber where damage caused by oxidation is the greatest. If undesirable side effects of the stabilizer occur, due to catalytic chain disintegration, these side effects will be limited to the fiber surface.
• Percentages named in the examples are by weight, where applicable. Temperatures are in degrees centigrade.
• the stabilizing effect of the combinations in the examples was determined by subjecting the stretched fibers to the action of hot air at 160 for 48 hours in a circulating air oven.
• the stabilizing effect was determined by ascertaining the percent decrease in specific viscosity of a 1% polyamide solution of 96% sulfuric acid. Aging tests, showing the percent decrease in tensile strength of the fibers, being proportional to the lowering of the viscosity, were not carried out.
• EXAMPLE 1 0.03% copper-II-acetate. H and 0.13% mercaptobenzimidazole were added to epsilonaminocaprolactam in a polymerization vessel. Chips manufactured by the polymerization were freed from oligomers by extraction with water, melted in a melt extruder at 270 and spun through a 34-hole nozzle to fibers of a total titer of 585 denier.
• aqueous KI solution 80 g./l. aqueous KI solution were applied to the spinning preparation by conducting it through two rollers.
• the amount of potassium iodide corresponded to an iodine content of 0.1, calculated on the weight of the fibers.
• the yarn thus obtained was then stretched in proportions of 1:3.505 over a heated stretcher.
• Polyamide chips produced from episilonaminocaprolactam having a solution viscosity of 1.94 (0.5% solution in m-cresol) were powdered with a mixture of 0.03% copper-I-chloride and 0.13% mercaptobenzimidazole, calculated on the weight of the chips. The mixture had been ground to a fine dust. Spinning and stretching were carried out as in Example 1, but without addition of KI to the spinning preparation. The specific viscosity drop was 6%.
• a process for heat stabilizing a polyamide fiber, bristle or foil produced by polymerizing, starting materials selected from the group consisting of epsilonamino carboxylic acid and caprolactam, and hexamethylene diamine and adipic acid to produce a polyamide then spinning and stretching same, said heat stabilizing being accomplished by adding to said polyamide a compound selected from the group consisting of heat stabilizing copper salts, organic aromatic amines and mixtures thereof, and a heat stabilizing alkali halide, the improvement which comprises incorporating said compound with the starting materials prior to their polymerization and applying said alkali halide to the surface of said produced polyamide upon the spinning of same into a fiber, bristle or foil and prior to the stretching.
• alkali halide is potassium iodide and the amount of said potassium iodide applied to the surface of the produced polyamide corresponds to an iodine content of 0.010.5% calculated on the weight of the fiber, bristle or foil.

Landscapes

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

Applications Claiming Priority (1)

Publications (1)

Family

ID=4392340

Family Applications (1)

Country Status (7)

Cited By (2)

Families Citing this family (4)

• 0
  • NL NL137488D patent/NL137488C/xx active
• 1966
  • 1966-09-16 CH CH1342666A patent/CH464436A/de unknown
• 1967
  • 1967-09-14 AT AT841467A patent/AT273496B/de active
  • 1967-09-14 ES ES345053A patent/ES345053A1/es not_active Expired
  • 1967-09-14 GB GB41933/67A patent/GB1145677A/en not_active Expired
  • 1967-09-15 NL NL6712653A patent/NL6712653A/xx unknown
  • 1967-09-15 FR FR1552903D patent/FR1552903A/fr not_active Expired
• 1969
  • 1969-08-27 US US853524A patent/US3642971A/en not_active Expired - Lifetime

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