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
  • D01F6/74—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from homopolycondensation products from polycondensates of cyclic compounds, e.g. polyimides, polybenzimidazoles
• • 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 present invention relates to a process for obtaining fibers thermostable by spinning in polyamide-imide solution and the fibers as well obtained.
• thermomechanical resistance for certain applications.
• polyamide-imides To improve the mechanical properties of polyamide-imides it has also prepared, according to FR 2 643 084 fibers based on polyamide-imides preferably derived from diphenyl ether-4,4 'diisocyanate. But such fibers have a low stretchability which does not allow access to low strand titles.
• 4,4 'diphenyl ether diisocyanate is a product with difficulty commercially accessible and expensive.
• the polyamide-imide used has a viscosity inherent ⁇ 0.8 dl / g.
• the dimethylalkylene urea used is preferably dimethylethylene urea or dimethylpropylene urea.
• the yarns and fibers according to the present invention can also be prepared by dry spinning of a solution of concentration 15 to 35%, preferably 20 to 30% in the dimethylalkylene urea of a polyamide-imide containing the chains of a copolymer A, B, C and D of the formula described above, with Ar 1 , Ar 2 , Ar 3 , R and M having the same meaning, in an evaporative atmosphere maintained at a temperature close to or above the boiling point of the solvent, the filaments at the outlet of the evaporative enclosure being freed of their residual solvent.
• they can be washed with water, optionally boiling and under pressure, dried in the usual way, preferably at a temperature above 80 ° C.
• They can also be heat treated at a temperature ⁇ 160 ° C under reduced pressure, and / or under an inert atmosphere. After being freed from their residual solvent, they are drawn at a temperature above 250 ° C, preferably above 300 ° C, preferably in the absence of oxygen.
• the total drawing rate practiced is at least 5 X, preferably at minus 6 X.
• Such polymers can be obtained by reaction (a), in substantially stoichiometric proportions and in the absence of catalyst, in an anhydrous polar solvent of metaphenylene diisocyanate, with at least minus an acid reagent comprising an aromatic anhydride-acid optionally an aromatic dianhydride, optionally a 3,5-dicarboxy alkali or alkaline earth benzene sulfonate, and optionally a diacid aromatic under the operating conditions described in the patent application French 1,600,067 filed on December 30, 1968.
• polymers can also be obtained by reaction (b) of diisocyanate indicated above and an acid reagent comprising a dianhydride aromatic, and an aromatic diacid, optionally of a dicarboxy-3,5-benzene sulfonate alkali or alkaline earth, in the absence aromatic acid anhydride, in stoichiometric proportions and in the absence of catalyst.
• an acid reagent comprising a dianhydride aromatic, and an aromatic diacid, optionally of a dicarboxy-3,5-benzene sulfonate alkali or alkaline earth, in the absence aromatic acid anhydride, in stoichiometric proportions and in the absence of catalyst.
• metaphenylenediisocyanate a minor proportion of another aromatic, aliphatic diisocyanate, or cycloaliphatic in order to improve certain properties of articles consistent; for example it can be useful for improving the properties fibers obtained from substituting up to 30% m-PDI with paraphenylenediisocyanate (p-PDI).
• p-PDI paraphenylenediisocyanate
• anhydride is preferably used trimellic and as aromatic dianhydride mention may be made of dianhydrides pyromellic acid, diphenyl acid 3,3 '4,4'-tetracarboxylic acid naphthalene-2,3,6,7-tetracarboxylic acid, diphenyl ether acid-3,3 ', 4,4' tetracarboxylic, 3,3 'diphenylsulfone, 4,4' tetracarboxylic and preferably, diphenylketone-3,3'4,4'-tetracarboxylic acid dianhydride.
• dianhydrides can be used as a mixture; and among the aromatic diacids, terephthalic and isophthalic acids are often used and, although terephthalic acid is preferred, other diacids may suitable, such as biphenyl-dicarboxylic acids or naphthalene-dicarboxylic acids.
• the trimellic anhydride used must be pure and in particular should not not contain more than 5 mol% of trimellic acid.
• the alkali metal dicarboxy-3,5-benzene sulfonate or alkaline earth is preferably sodium or potassium sulfonate.
• dimethylalkylene urea for example dimethylethylene urea or dimethylpropylene urea
• polyamide-imide spinning solutions have the advantage of being lightly colored. They must also have a viscosity allowing their spinning, generally between 40 and 100, preferably 50 and 80 Pa.s (between 400 and 1000, preferably 500 and 800 poises) measured using a viscometer known in the trade under the brand EPPRECHT RHEOMAT 15 for wet spinning, and 150 to 300 Pa.s (1,500 to 3,000 poises) for dry spinning.
• the spinning solution may have a polymer concentration between 10 and 35%, preferably between 15 and 25%. It can contain various additives intended to modify the appearance or the final properties of the yarns obtained such as, dyes, matifiers, stabilizers.
• the temperature of the spinning solution can vary within large limits depending on the viscosity of the spinning solution.
• a solution having a low viscosity can easily be extruded at temperature ordinary, while it is preferable to hot extrude, for example at 120 ° C or even more, a solution of high viscosity to avoid using too large sector pressures.
• the coagulating bath used in the process according to the invention is an aqueous solution containing from 30 to 80% by weight of dimethylalkylene urea (DMAU) although it is often beneficial to use a bath containing more than 50% by weight of DMAU to obtain filaments of better stretchability, therefore better final properties.
• DMAU dimethylalkylene urea
• the speed of passage of the filaments in the coagulating bath can vary within wide limits, depending on its solvent concentration and the distance of travel of the filaments in this bath.
• This passage speed filaments in the coagulating bath can easily be chosen between 10 and 60 m / min, for example, although higher speeds can be reached. There is generally no advantage in spinning at lower speeds for reasons of profitability of the process. In addition, excessively high speeds of passage of the filaments in the coagulating bath reduces the stretchability of the filaments in the air. The speed of passage of the filaments in the coagulating bath will therefore chosen to take into account both profitability and desired qualities on the thread finished.
• the temperature of the coagulating bath can be chosen between 15 and 40 ° C. for example, it is generally between 20 and 30 ° C.
• the filaments thus obtained are then drawn, preferably in air, at a rate of at least 2 X or more.
• the residual solvent is removed from the filaments by known means, generally by washing with water running against the current or on washing rollers, at room temperature.
• the wires obtained by dry spinning are pre-stretched in the spinning and then the residual solvent is removed, either by heat treatment at a temperature above 100 ° C, either by washing with water, preferably with water boiling under pressure.
• the washed filaments are then dried by known means, for example in a dryer or on rollers.
• the temperature of this drying can vary within wide limits as well as the speed which is all the greater the higher the temperature high. It is generally advantageous to carry out drying with elevation progressive temperature, this temperature can reach and even exceed 200 ° C for example.
• the filaments from which the solvent and water have been removed undergo a second stretching to improve their mechanical qualities and to allow reach fine stranded titles, which may be less than 1 dtex / strand.
• the overstretching can be carried out by any known means: oven, plate, rollers, at a temperature of at least 250 ° C, preferably at least 300 ° C up to 400 ° C, preferably in the absence of oxygen.
• Over-drawing generally carried out at a rate of at least 2 X, of preferably at least 3 X, up to 4 or 5 X, so that the overall rate stretching is at least 5 X, preferably at least 6 X.
• the PAI yarns derived from metaphenylene diisocyanate has the unexpected characteristic of exhibiting excellent stretchability and therefore allow access to titles that are thinner than those polyamide-imides from other diisocyanates such as 4,4 'diphenylmethane diisocyanate or 4,4 'diphenyl ether diisocyanate described previously in French patents 2,079,785 and 2,643,084. They also have the advantage less coloring and above all better thermomechanical behavior, as will be seen later in the description.
• the yarns and fibers according to the invention preferably have a inherent viscosity ⁇ 0.8 dl / g, preferably 0.9 dl / g.
• thermomechanical behavior is highlighted by the retention of the level of the modulus of elasticity by linear rise in temperature with a temperature increase from 50 to 400 ° C approximately.
• the retention of modulus of elasticity is ⁇ 40% at 310 ° C.
• PAI-based wires from m-PDI have a very low initial coloration, allowing them to be dyed in very light shades, unusual for these types of product.
• They also have tenacity retention after exposure 1000 hours at 200 ° C of at least 75%, preferably at least 80%, and after 5,000 hours exposure to 200 ° C of at least 65%, preferably at minus 70%.
• the yarns according to the invention also have excellent stretchability, making it possible to reach very low strands, less than 1 dtex / strand, which is quite unusual for thermostable wires and their gives a very soft textile feel. They also have excellent mechanical properties, toughness at break, modulus of elasticity, and a low elongation. Thus they combine a textile touch and good characteristics mechanical and thermomechanical. They can be dyed easily with basic dyes.
• wires When the wires are free of units (B), they can also enter in the composition of many composites, especially for applications dielectric.
• metaphenylene diisocyanate is known for its accessibility and its price of low market, which represents a significant industrial advantage; this is particularly significant compared to yarn from polyamide-imides prepared from 4,4 'diphenyl ether diisocyanate.
• Mn and Mw are determined by gel exclusion chromatography (GPC) in NMP at 80 ° C and 0.1 mole / liter of lithium bromide, the masses being expressed relative to a polystyrene calibration.
• Polydispersity index 1 corresponds to the ratio Mw / Mn
• a 21% solution in dimethylethylene urea of a sulfonated copolyamide-imide is prepared by reaction, in the absence of catalyst, of: - DMEU 257.1 g 244 ml - toluylene diisocyanate 87.0 g 0.5 mole - trimellic anhydride 76.8 g 0.4 mole (80 mol%) - terephthalic acid (AT) 13.28 g 0.08 mole (16 mol%) - dicarboxy-3,5 benzene - sodium sulfonate 5.36 g 0.02 mole (4 mol%) - DMEU of dilution 236.7 g 250 ml Molar mass Mn 50,020 Polydispersity I 1.78 Inherent viscosity 0.97 dl / g
• a 21% concentration solution with a viscosity of 60.3 Pa.s is obtained. (603 poises) measured on an EPPRECHT RHEOMAT 15 viscometer. D + E tank at 25 ° C.
• the solution maintained at a temperature of 70 ° C. is extruded at through a die with 62 orifices, 0.06 mm in diameter, into a bath DMEU / water coagulant containing 62% by weight of DMEU and 38% by weight of water, maintained at 27 ° C., the length of the path of the filaments in this bath being approximately 1 meter.
• the filaments are taken up by a first train of rollers and drawn into the air between the first and second train of rollers at a rate of 2 X. They are then washed with water against the current in a washing tub, dried in an oven maintained at around 150 ° C, then over-stretched in an oven maintained at a temperature of around 350 ° C.
• Example 1 Is prepared in the manner indicated in Example 1 a polyamide-imide by replacing the TDI with metaphenylene diisocyanate in identical molar proportion.
• the PAI obtained has a molar mass Mn : 36,560 and a polydispersity index: 2.05 and has an inherent viscosity of 0.86 dl / g.
• the viscosity of the solution measured on an EPPRECHT viscometer RHEOMAT is: 56.6 Pa.s (566 poises).
• the polyamide-imide solution thus obtained, concentration: 21% is spun and processed as shown in Example 1, the air-drawing being performed at a rate of 2.3 X and overstretching also at a rate of 2.3 X, the rate overall stretch being 5.29 X.
• a solution with a concentration of 21% in DMPU is obtained, with a viscosity of 81.0 Pa.s (810 poises) measured as indicated in Example 1.
• Example 1 The solution thus obtained is spun as indicated in Example 1 and the filaments obtained are drawn at a drawing rate of 2 X, washed and dried, then over-stretched in an oven maintained at 335 ° C at a rate of 3 X.
• the filaments obtained have the following characteristics: Strand title (dtex) 2 Breaking toughness 30 g / tex Elongation% 15 Thermomechanical behavior - Retention of the elastic modulus: at 310 ° C: conservation of 43% of the initial modulus.

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• 1991
  • 1991-12-24 FR FR9116339A patent/FR2685354B1/fr not_active Expired - Lifetime
• 1992
  • 1992-12-18 TW TW081110176A patent/TW218898B/zh active
  • 1992-12-21 DE DE69224974T patent/DE69224974T2/de not_active Expired - Lifetime
  • 1992-12-21 EP EP92420475A patent/EP0549494B1/fr not_active Expired - Lifetime
  • 1992-12-21 AT AT92420475T patent/ATE164640T1/de not_active IP Right Cessation
  • 1992-12-21 IL IL10419892A patent/IL104198A/en not_active IP Right Cessation
  • 1992-12-21 ES ES92420475T patent/ES2113934T3/es not_active Expired - Lifetime
  • 1992-12-22 ZA ZA929951A patent/ZA929951B/xx unknown
  • 1992-12-23 MX MX9207511A patent/MX9207511A/es unknown
  • 1992-12-24 CN CN92113840A patent/CN1053235C/zh not_active Expired - Lifetime
  • 1992-12-24 JP JP4344752A patent/JP2607816B2/ja not_active Expired - Lifetime
  • 1992-12-24 KR KR1019920025530A patent/KR100198184B1/ko not_active IP Right Cessation
• 1996
  • 1996-04-24 JP JP8102845A patent/JP2726812B2/ja not_active Expired - Lifetime

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