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
  • D01F6/02—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from homopolymers obtained by reactions only involving carbon-to-carbon unsaturated bonds
  • D01F6/18—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 unsaturated nitriles, e.g. polyacrylonitrile, polyvinylidene cyanide
• • 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
  • D01D5/12—Stretch-spinning methods
  • D01D5/16—Stretch-spinning methods using rollers, or like mechanical devices, e.g. snubbing pins

Definitions

• the invention relates to filaments and fibers made of polyacrylonitrile or Polyacrylnitrilcopolymeren, which are composed of Acrylnitrilbausteinen for the most part, and whose initial modulus - based on 100% elongation - 13 higher than 00 cN / tex. Furthermore, a method for producing such threads and fibers is described.
• the maximum effective drawing in the examples was approximately 1: 6.8, effective drawing being understood to mean the actual drawing effective, for example, on the titer of the individual threads. It can be calculated from the individual stretch values, which, however, still have to be corrected for the shrinkage during stress-free drying.
• filaments and fibers of polyacrylonitrile or acrylonitrile copolymers to provide, g sm o d uli having beginni than 1300 cN / tex and their manufacturing processes as little as possible is different from the normal spinning process and especially not the use of of steam stretching zones or the like but also does not require a special maturing process for spinning viscose or the use of special solution polymers.
• the threads according to the invention have an initial modulus of over 1,300 cN / t ex in the usual titer range (about 1.5 to about 15 dtex). These values are preferably between 1400 and 2500 cN / tex.
• the threads and fibers with these high initial moduli are particularly well suited for technical applications such as B.
• the invention is also based on a method for producing these fibers and threads by a wet or dry spinning process, the wet stretching of the spun threads being carried out during the washing treatment, the threads then being dried and then subjected to hot stretching.
• the process according to the invention is characterized in that the threads are dried under tension, if necessary in cable or strand form, on hot rollers and then subjected to a contact stretching of at least 1: 1.5, the effective total stretching having to be at least 1: 9.
• the stretching in the dry hot state should be e.g. be understood by using panel radiators.
• Polymers can be used whose relative solution viscosities - measured in 0.5% dimethylformamide solutions - are in the range from 1.7 to 6.0. Good results under economical conditions are achieved with polymers which are in a viscosity range of approximately 1.85 to 3.5, particularly good results are provided by polymers in the viscosity range between 2.5 and 3.5.
• the polymers used should preferably have a content of at least 90% acrylonitrile units. achieved. Particularly good textile values are obtained for polymers that are made up of at least 99% acrylonitrile units.
• the dissolving conditions are to be selected so that the most homogeneous, gel particle-free spinning solution is obtained.
• Scattered light measurements using a laser as the light source are particularly suitable for checking the quality of the spinning solution. Only flawless spinning solutions which show very low scattered light values enable the high draws required according to the invention.
• the spinning solutions can be prepared both continuously and discontinuously. Inorganic or organic additives can be incorporated into the spinning solution, e.g. Matting agents, stabilizers, flame retardants, etc.
• the spinning process according to the invention is characterized by a high effective total drawing of at least 1: 9.
• the effective total drawing should be at least 1: 9 by the method according to the invention. Effective total draw ratios of 1:10 to 1:25 are preferred, particularly preferred effective total draw ratios between about 1:12 and 1:22.
• the method according to the invention can be carried out on conventional thread or fiber spinning systems. New techniques that were not previously common are not required. In particular, it is not necessary to use a special drawing chamber in which the threads, for example in the form of cables, are exposed to the action of steam under pressure. The process is characterized by high total draw values of the freshly spun threads, an effective minimum draw of 900% being required. This effective total drawing takes place in several stages. First, the threads are wet-drawn in one or gradually in several hot baths before or after washing out the residual solvent content. The temperature of the stretching bath media, which usually consist of mixtures of water and the solvent, should be kept as high as possible. Temperatures a little below the boiling point of the bath liquid are preferred.
• baths which contain other stretching bath media are also possible, for example glycol or glycerol, optionally in a mixture with the polymer solvent, in which stretching temperatures above 100 ° C. can also be selected.
• the threads are prepared in a preparation bath and then in the usual manner by the Exposure to rotating pairs of press rolls as far as possible free of adhering water.
• the preparation applied in the preparation bath can influence the stretching behavior of the threads. It should therefore be selected from known preparation mixtures that shows a low thread-thread friction.
• the threads are then dried under tension on hot rollers.
• a small amount of shrinkage which often proves to be advantageous for the subsequent stretching, can be permitted on drying;
• care must be taken that the cables always run under tension over the drying rollers.
• the temperatures of the rollers should be chosen so that the cable leaves the dryer with a very low residual moisture of less than 1%. Temperatures in the range from 140 to 220 ° C. have proven particularly favorable for these rolls, but this does not exclude the use of higher or lower temperatures. It is also possible to dry on the rollers at different temperatures.
• the spun tow is stretched again using dry heat at least 1.5 times its length.
• This stretching can also take place in one or more stages.
• the cable can be heated by the methods customary in the art, for example by rotating hot rollers, by contact via hot plates, in a hot air duct or by radiation, in particular infrared radiation.
• Gradual stretching in which different heating methods are used, can also be used. Such combinations are particularly advantageous whenever stretching from or between hot rolls is carried out in the first stretching step and one of the three other methods described is used in the second step.
• the drawing temperatures are determined by the type of poly used and influenced in part by the previous stretching and drying conditions. A temperature range of about 120 to 250 ° C. is generally suitable, and the range of 140 to 200 ° C. is particularly favorable.
• the threads After stretching, the threads are cooled and, according to known methods, either wound up to form continuous material or cut into fibers with the desired cutting length. If required by the field of application, a special preparation can be applied to the threads or fibers before or after cutting.
• 1700 g of a suspension precipitation polymer of 99.5% acrylonitrile and 0.5% methyl acrylate with a relative viscosity of 2.85 are dispersed in 8300 g DMF at -30 ° C and for 90 minutes at 90 ° C with stirring to a homogeneous spinning solution solved. After filtering, the solution is pressed at a rate of 16.2 ml / min through a 100-hole nozzle, hole diameter 0.06 mm, into a precipitation bath consisting of 50% DMF and 50% water and a temperature of 50 ° C. The threads obtained are drawn off after an immersion length of 50 cm at a speed of 5.5 m / min.
• the thread is drawn off from the second duo at 33.3 m / min and over 4 heated plates, which alternately touch the thread from below and above, at temperatures of 145, 145, 165 and 168 ° C to 95 m / min with the help of a stretched unheated duos and then wound on spools.
• the effective total draw ratio is calculated to be 1: 17.3 in this case.
• the threads obtained in this way had the following properties:
• the individual capillaries of the thread produced in this way had the following properties:
• the thread obtained was drawn off after an immersion length of 50 cm at 5.0 m / min and in a drawing bath which contained 60% DMF and 40% water at 99 ° C., the thread was drawn to 33 m / min, then with water washed and dried after going through an aviva bath on 2 duos without approval of shrinkage.
• the surface temperatures of the duos were 120 and 140 ° C.
• the thread was then drawn to 68 m / min over 4 plates heated to 135 ° C., corresponding to an effective total drawing ratio of 1: 13.6.
• the individual capillaries of the thread showed the following properties
• 1400 g of a precipitation polymer made of 100% acrylonitrile with a relative viscosity of 3.0 were dissolved in 8600 g of DMF to form a spinning solution, filtered and, at a delivery rate of 16 ml / min, through a 100-hole nozzle, hole diameter 0.06 mm, in one Precipitation bath consisting of 55% DMF and 45% water at 50 ° C.
• the thread obtained was drawn off from the precipitation bath at 5.5 m / min and drawn to 29.3 m / min in a drawing bath consisting of 60% DMF and 40% water at 99 ° C.
• the thread was then washed in water at 85 ° C., then passed through an Aviva bath and then dried on 2 duos with surface temperatures of 140 and 165 ° C. A shrinkage of 2.5 m / min was permitted on the duos, but the thread was drawn off at 30.3 m / min from the second duo and over 4 hot plates with surface temperatures of 140, 14U, 150 and 150 ° C to 72 m / min stretched.
• the Individual filaments of the thread thus obtained showed the following properties
• the thread was dried in the drum dryer in a first stage at 165 ° C. without the approval of shrinkage, in a second stage at 180 ° C., stretching to 63.9 m / min between the first and second stage.
• the thread then reached a third stage of the drum dryer, which was operated at 175 ° C. and the cable was stretched again to 69.2 m / min between the second and third stages.
• the cable passed through 8 hot-alternating plates arranged at the top and bottom, which had a surface temperature of 180 ° C, and between which the cable was stretched to 77.2 m / min, corresponding to an effective total stretching of 1: 11.9.
• Example 1 was repeated, but 5%, based on the polymer, of titanium dioxide was added as a matting agent to the spinning solution.
• the individual filaments of the thread had the following properties
• the individual filaments obtained had the following properties:

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• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Health & Medical Sciences (AREA)
• General Chemical & Material Sciences (AREA)
• Chemical & Material Sciences (AREA)
• Toxicology (AREA)
• Mechanical Engineering (AREA)
• Artificial Filaments (AREA)
• Yarns And Mechanical Finishing Of Yarns Or Ropes (AREA)
• Materials For Medical Uses (AREA)
• Prostheses (AREA)
• Reinforced Plastic Materials (AREA)

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• 1980
  • 1980-07-23 DE DE19803027844 patent/DE3027844A1/de not_active Ceased
• 1981
  • 1981-07-16 AT AT81105600T patent/ATE7236T1/de not_active IP Right Cessation
  • 1981-07-16 EP EP81105600A patent/EP0044534B1/fr not_active Expired
  • 1981-07-16 DE DE8181105600T patent/DE3163294D1/de not_active Expired
  • 1981-07-21 DD DD81231964A patent/DD201702A5/de unknown
  • 1981-07-21 IL IL63377A patent/IL63377A/xx unknown
  • 1981-07-22 BR BR8104734A patent/BR8104734A/pt unknown
  • 1981-07-22 NO NO812514A patent/NO152946C/no unknown
  • 1981-07-22 JP JP56113779A patent/JPS5751810A/ja active Pending
  • 1981-07-22 DK DK326281A patent/DK326281A/da not_active Application Discontinuation
  • 1981-07-22 ZA ZA815005A patent/ZA815005B/xx unknown
  • 1981-07-22 CA CA000382253A patent/CA1170011A/fr not_active Expired

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