Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J3/00—Processes of treating or compounding macromolecular substances
  • C08J3/02—Making solutions, dispersions, lattices or gels by other methods than by solution, emulsion or suspension polymerisation techniques
  • C08J3/09—Making solutions, dispersions, lattices or gels by other methods than by solution, emulsion or suspension polymerisation techniques in organic liquids
  • C08J3/091—Making solutions, dispersions, lattices or gels by other methods than by solution, emulsion or suspension polymerisation techniques in organic liquids characterised by the chemical constitution of the organic liquid
• • 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
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J2333/00—Characterised by the use of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides, or nitriles thereof; Derivatives of such polymers
  • C08J2333/18—Homopolymers or copolymers of nitriles
  • C08J2333/20—Homopolymers or copolymers of acrylonitrile

Definitions

• This invention relates to spinning solutions containing acryl onitrile polymers and a method of preparing such solutions. More particularly, the invention is directed to spinning solutions of homopolymers, or copolymers of acrylonitrile which are dissolved in a mixture of dimethylformamide and an acetal.
• Dimethylformamide is a well known and a suitable solvent for the production of fibers from acrylonitrile polymers. It has been observed, however that the struc ture of fibers obtained by spinning solutions. of acrylonitrile polymers dissolved in dirnethyl formarnide was often detrimentally aitected by that solvent. In the so called wet spinning process wherein the solution of the acrylonitrile polymer in dimethyl formamide is coagulated by the action of a suitable coagulating agent the dimethylformamide which is still present in the freshly spun fibers possesses such a vigorous coagulation tendency that sometimes unsatisfactory formation of the fibers occurs. There are several fields wherein such fibers cannot be used.
• a more particular object of the invention is to provide spinning solutions of acrylonitrile polymers comprising a mixture of dimethylformamide and an acetal as a solvent.
• a still further object of this invention is the production of synthetic fibers by spinning the solutions of acrylonitrile polymers dissolved in a mixture of dimethylformamide and an acetal.
• mixturcs of dimethylformamide and at least one acetal are excellent solvents for acrylonitrile polymers; and that the solutions of such polymers in such mixtures of solvents are especially valuable for the production of synthetic fibers.
• Such spinning solutions may contain as acetals, for instance, an acetal obtained by the interaction of lformaldehyde, acetaldehyde, their higher homologues as well as of benzaldehyde with monohydric or polyhydric alcohols such as methyl, ethyl, propyl, or n-butyl alcohol and their homologues or ethylene glycol or other polyhydric alcohols.
• Mixtures of different acctals with dimethylformamide may also be used.
• the solvent mixtures should contain dimethylformamide and a smaller amount of the acetal as for instance, from 5% to preferably from 8% to 12% acetal. When mixtures of diiferent acetals are used in combination with dimethylformamide their total amount should also lie between 5% and 15%, preferably between 8% and 12%.
• the spinning solution should usually contain for 100 parts by weight of the solvent mixture from 17.6 to 33.3 parts by weight of the acrylonitrile polymers.
• the manufacture of the spinning solutions with the mixtures cf dimethylformamide and at least one acetal may be carried out in the usual way.
• the acrylonitrile polymer which may be preferably in powdered form is mixed, for example, with the solvent mixture at low temperature to form a dispersion which is then heated to a higher temperature to form a homogeneous solution.
• T he finely powdered acrylonitrile polymer may be introduced, for instance, at a temperature of 15 C. into a vacuum vessel which contains the solvent mixture through a bucket wheel while stirring. This mixture is then stirred at a temperature of about 15 C. or higher, but not exceeding 20 C. while deaerating until a finely distributed dispersion is obtained.
• the mixture is then gradually heated to 110 C.
• the spinning solutions according to this invention are useful for the production of synthetic fibers by the known wetor the known dry spinning process. It is advantageous when the wet spinning process is carried out to' coagulate the spinning solution of this'invention more slowly than when coagulating a straight dimethylformamide solution so that markedly better formation of the fiber is achieved. At the same'time the properties of thestretched fiber are improved so that they possess, after being stretched to from 4 to 10 times, markedly better textilecharacteristics. Similar improvements are obtained whenthe solutions are dry-spun by the process wherein the solvent mixture is evaporated during the spinning operation. v
• polymer of acrylonitrile or acrylonitrile polymer used herein include both fiber or filament forming homopolymers and copolymers of acrylonitrile.
• copolymers of acrylonitrile those copolymers are preferred which contain at least by weight of acrylonitrile and up to 20% by Weight of another polymerizable compound such as acrylic acid amide, acrylic acid methyl ester, methacrylic acid methyl ester, fumaric acid dimethyl ester, vinylacetate, vinylimidazole, vinylcarbazole, vinylpyridine and methyl vinylketone.
• Example 1 20 kg. of polyacrylonitrile having a K-value of according to Fikentscher are dispersed at a temperature between 15 C. and 20 C. in a solvent mixture consisting of 72 kg. dimethylformamide and 8kg. of dipropylformal While deaerating. The dispersion is gradually heated and forms at a temperature of between C. and C. a solution which may be spun according to the dry or the wet spinning process.
• (a) Dry spinning process The dry spinning process is carried out in a dry spinning shaft having a length of 4 meters and an internal diameter of 300 mm.
• a counter current method is used wherein the direction of the stream of the drying gas is counter to the direction of the taken-oil? thread.
• the drying gas has a speed of 30 cm. per second and a temperature of C.
• the thread is drawn with a velocity of 200 meters per minute.
• Example 2 In accordance with Example 1, 22 kg. of polyacrylonitrile with a K-value of 80 are dissolved in a solvent mixture consisting of 88% by weight of dimethylformamide and 12% by weight of dibutylformal. This solution may be processed to form synthetic fibers in accordwith Examples 1(a) and 1(b) either by the dry or by the wet spinning method.
• Example 3 19 kg. of a copolymer of 90% acrylonitrile and of acrylic acid amide with a K-value of about 90 are dissolved in 81 kg. of a solvent mixture consisting of 92% dimethylformamide and 8% of dibutyl acetal (obtained by interaction of acetaldehyde and n-butanol). Threads are spun from the solution as in Example 1(b). After the usual stretching the threads have a tensile strength of 30 Reisskilometer at an elongation of 30% to 35%.
• Example 4 19.5 kg. of polyacrylonitrile with a K-value of 88 are dissolved as in Example 1 in 80.5 kg. of a mixture of 93% by weight of dimethylformamide, 4% by weight of dipropylformal and 3% by weight of dibutyl acetal so that a ready-for-use spinning solution is obtained. Threads are produced from the solution in accordance with the method of Example 1(a). The filaments, after being stretched to 9 times their original length, have a tensile strength of 38 Reisskilometer at an elongation of 21%.
• a spinning solution in accordance with claim 1 wherein the polymer is polyacrylonitrile.
• a polymer selected from the class consisting of homopolymers of acrylonitrile and copolymers of a monomeric mixture of which at least 80 percent is acrylonitrile and the balance is an ethylenically unsaturated compound which comprises dissolving the said polymer in a mixture

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• Chemical & Material Sciences (AREA)
• General Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Health & Medical Sciences (AREA)
• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Dispersion Chemistry (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Organic Chemistry (AREA)
• Toxicology (AREA)
• Artificial Filaments (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=6201125

Family Applications (1)

Country Status (6)

Citations (1)

• 0
  • NL NL195100D patent/NL195100A/xx unknown
  • NL NL82878D patent/NL82878C/xx active
  • BE BE535969D patent/BE535969A/xx unknown
• 1955
  • 1955-02-25 CH CH332096D patent/CH332096A/de unknown
  • 1955-02-28 FR FR1119636D patent/FR1119636A/fr not_active Expired
  • 1955-03-17 GB GB7836/55A patent/GB765549A/en not_active Expired
  • 1955-03-18 US US495333A patent/US2839486A/en not_active Expired - Lifetime

Patent Citations (1)

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