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
  • 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

Definitions

• This invention relates to a process for the production of yarns containing at least 50% acrylonitrile having a tight reversible crimp. More particularly, this invention relates to a process for the production of yarns and fibers comprising at least 50% acrylonitrile and having a tight reversible crimp suitable for use in knitted and woven goods.
• Synthetic yarns and fibers such as polyamides, polyesters, and polyacrylonitriles may be woven into fabrics having high strength, improved durability, improved launderability, and wrinkle resistance.
• fabrics produced from synthetic yarns especially those produced from continuous filament yarns, do not produce products which have asthetic properties similar to natural yarns.
• fabrics Woven from such filamentary yarns tend to have a slick, cold hand and often have poor luster and cover.
• a desirable synthetic fabric should have a warm, dry hand, good luster and other properties of a naturally occurring wool-type fabric.
• U.S. Pat. 3,447,998 discloses a process for producing self-crimping acrylonitrile fibers utilizing the wet spinning method. However, this process utilizes a coagulating bath which does not appreciably penetrate into the fibers. This creates a fiber with a non-uniform skin, a type of sheath-core relationship, therefore causing the fibers to crimp and curl. This process, however, is not suitable for use in producing fibers containing less than 80% acrylonitrile. US. Pat.
• 3,402,234 discloses a method for obtaining bent fibers by spinning an acrylonitrile polymer solution into a coagulating bath containing t-butyl or t-amyl' alcohol and a polymer solvent.
• the polymers produced according to the method of this patent are not self-crimping and also have inferior tensile properties,
• Patented June 5, 1973 such as tenacity and elongation to rupture.
• French Pat. 1,385,441 a method is disclosed for preparing low count vinyl filaments by spinning these polymers into a coagulating bath containing a polymer solvent and a coagulant.
• the process disclosed in this patent also does not produce self-crimping acrylonitrile filaments.
• inherently self-crimping yarns and filaments containing at least 50% acrylonitrile are produced by extruding the acrylonitrile base solution into a coagulating bath containing a solvent for the acrylonitrile, isopropanol, and between 0 and 5% water, drawing the filaments in a second bath containing a solvent for the acrylonitrile, isopropanol and between 0 and 5% water, cutting and washing the filaments in a relaxed state, immersing the filaments in a relaxed state in boiling water, and drying the filaments in a relaxed state.
• the primary object of this invention to provide a process for the production of acrylonitrile based yarns and filaments having a tight reversible crimp.
• -It is yet a further object of this invention to provide a process for producing acrylonitrile based yarns and filaments having a tight reversible crimp and superior physical properties.
• a still further object of this invention is to provide a process for producing tightly crimped acrylonitrile yarns produced by the wet spinning process utilizing a subsequent treatment bath containing isopropanol.
• the process of the present invention which is suitable for producing crimped filaments, fibers, and yarns from solutions of homopolymers, copolymers, and terpolymers containing at least 50% acrylonitrile, comprises: spinning an acrylonitrile based polymer solution, comprising the acrylonitrile based polymer dissolved in an organic solvent, into a coagulant bath containing an organic solvent for the acrylonitrile polymer, isopropanol, and between 0 and 5% water; drawing the spun filaments in a second bath comprising a solvent for the acrylonitrile polymer, isopropanol, and between 0 and 5% water; cutting and washing the filaments in a relaxed state; immersing the filaments in boiling water in a relaxed state; and drying the filaments in a relaxed state.
• the acrylonitrile based polymers suitable for use in the process of the present invention include homopolymers of acrylonitrile, mixture of acrylonitrile polymers with other polymers, copolymers and graft copolymers containing at least 50% by weight acrylonitrile and less than 50% by weight of one or more ethylenically unsaturated monomers copolymerizable with acrylonitrile, such as vinyl chloride, vinyl acetate, vinylidene chloride, acrylic acid, methacrylic acid, esters and amides; methacrylonitrile; compounds containing a carbocyclic acid group such as itacon-ic acid, or a sulphonic acid such as vinylsulphonic compounds, allyl and methallyl sulfonic acids, sulfonated aromatic compounds, for example styrenesulphonic acids and vinyl oxyarene sulfonic acids, vinyl derivatives of basic nature such as vinylpyridiue and its alkyl derivatives,
• the acrylonitrile polymer is first dissolved in an organic solvent for the acrylonitrile polymer to form a polymer solution containing from 10 to 30% polymer.
• acrylonitrile based polymers can be dissolved in this solvent for the acrylonitrile utilizing any well known technique.
• Solvents suitable for use in the process of this invention include dimethylformamide, dimethylacetamide, dimethylsulfoxide, etc. Although the above solvents are preferred, any other solvent which is capable of dissolving the acrylonitrile based polymer may be used in the process of the present invention.
• This solution of the acrylonitnile based polymer in the organic solvent is then extruded into a coagulating bath comprising from 37 to 49% by weight of the solvent for the acrylonitrile based polymer, from 61 to 49% by weight of isopropanol, and from to by weight, and preferably from 0.1 to 2%, water.
• the temperature of this coagulating bath is generally kept below 30 C. and preferably between 0 and 20 C.
• the filaments thus formed are then drawn in a bath comprising from 37 to 49% by weight of the solvent for the acrylonitrile based polymer and from 61 to 49% isopropanol.
• this bath may also contain a small proportion of water, i.e., from 0 to 5% water, the water content is preferably from 0.1 to 2% by weight of water.
• the temperature of the drawing bath is preferably between 80 and 95 C.
• the rate of drawing in the drawing bath is generally greater than 3X (200%) and preferably between 5x (400%) and X (900%).
• the filaments may be slightly drawn after leaving the coagulating bath and before entering the drawing bath at ambient temperature by means of a simple adjustment of the relative speeds of the successive rollers controlling the advance of the filaments. These filaments then are drawn in the drawing bath with the composition as defined above such that the total draw ratio is greater than 3 X, and preferably between 5 X and 10X.
• the drawing operation may be completed in a single stage or may be a series of'drawing operations, it is preferable to draw the filaments in a continuous manner following the wet spinning operation.
• the filaments are cut into fibers in any conventional manner.
• the length of these fibers depends entirely upon their later use, and are generally from 20 to 150 mm.
• These cut fibers are then washed in water at ambient temperature in at least one vat or tub with the water being passed countercurrent to the direction of the fibers to remove the solvent and isopropanol.
• the solvent and isopropanol, which is recovered, may be recycled for reuse.
• the washing step may also be performed prior to the cutting operation.
• the cut and washed fibers are immersed, while in a relaxed state, in boiling water for about 30 seconds in order to develop the crimp and are then dried by any conventional means, while still in a relaxed state.
• a thermal treatment may also be employed subsequent to drying utilizing any conventional means in order to further reduce shrinkage of the fibers produced by the present invention.
• the fibers produced according to the process of the present invention have a tight, stable and reversible crimp and do not require any further mechanical crimping operations. These fibers also have a good dyeing aifinity and also a good elongation and a high tenacity. These fibers also are particularly Well suited for producing woven and knitted fabrics.
• EXAMPLE 1 A solution containing 21.5% of a tel-polymer of 92.2% acrylonitrile, 7.2% methyl methacrylate, and 0.6% sodium methallyl sulfonate in dimethylformamide' is prepared at 70 C.
• the specific viscosity of this polymer solution is 0.400 (a 0.2% solution in dimethylformamide at 20 C.).
• This polymer solution is extruded througha spinneret having 200 holes 0.05 mm. in diameter into a coagulating bath containing 2% water, 48% dimethylformamide, and 50% isopropanol, the temperature of the coagulating bath being 0C.
• the filaments obtained from this coagulating bath are then drawn in air at ambient temperature to a draw ratio of 2.90 These filaments are then drawn in a bath containing 2% water, 48% dimethylformamide, and 50% isopropanol kept at C.'so as to obtain a total draw ratio of 7.9x. These filaments are then out into fibers 120 mm. long and washed in a relaxed state in water at ambient temperature and flowing countercurrent to the direction of travel of the fibers. The fibers are then immersed in boiling water in a relaxed state so as to form the crimp. The fibers are then dried in a relaxed state at 70 C. and then subjected to a heat treatment in the presence of steam at C. Whilein the relaxed state.
• the tests conducted on the fibers include:
• Tensile properties.elongati0n to rupture and tensile strength measured after treatment either in the conditioned state, i.e., at 20 C. and 65% humidity, or in the wet state, i.e., after immersion in water.
• Crimp properties-level of crimping, frequency of crimping, and permanence are calculated according to the following formulae:
• Example 1 The tensile and crimping properties measured as indicated in Example 1 are as follows:
• Example 2 Utilizing the procedure of Example 1 the following acrylonitrile polymers and copolymers are mixed with enough dimethylformamide to form a 20% solution and these solutions are extruded into a coagulating bath containing 2% water, 48% dimethylformamide, and 50% isopropanol, maintained at 0 C. These filaments are also drawn in a drawing bath having the same composition as the coagulating bath kept at 90 C. to a draw ratio of 7.9x. After cutting, Washing, and immersing in boiling water, these fibers are dried at 70 C.
• compositions when treated according to the process of the present invention produces fibers which have excellent crimp level and frequency and the filaments also have excellent tensile properties and count.
• the fibers are then drawn in a drawing bath having a composition corresponding to the individual coagulant bath compositions noted above. After this drawing treatment the filaments are cut and Washed, dried and given a heat treatment. Each of these fibers produced has excellent crimp, count and tensile properties.
• the fibers and filaments produced utilizing the process of the present invention have superior crimp properties, and also excellent count and tensile properties.
• a process for the production of crimped yarns and fibers from solutions of an acrylonitrile polymer selected from homopolymers of acrylonitrile and copolymers of at least 50% acrylonitrile with up to 50% of at least one ethylenically unsaturated monomer copolymerizable therewith comprising:
• compositions of the drawing bath and the coagulating bath are substanthe coagulating bath is between 0 and 20 C.

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• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Health & Medical Sciences (AREA)
• Toxicology (AREA)
• Artificial Filaments (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=9054520

Family Applications (1)

Country Status (8)

Cited By (4)

• 1970
  • 1970-04-24 FR FR7014955A patent/FR2088772A5/fr not_active Expired
• 1971
  • 1971-02-03 BE BE762460A patent/BE762460A/xx unknown
  • 1971-03-03 LU LU62711D patent/LU62711A1/xx unknown
  • 1971-04-20 BR BR2329/71A patent/BR7102329D0/pt unknown
  • 1971-04-22 NL NL7105471A patent/NL7105471A/xx unknown
  • 1971-04-22 US US00136566A patent/US3737504A/en not_active Expired - Lifetime
  • 1971-04-23 DE DE19712119935 patent/DE2119935A1/de active Pending
  • 1971-04-26 GB GB1142071*[A patent/GB1318024A/en not_active Expired

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