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
  • D01F6/08—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 halogenated hydrocarbons
  • D01F6/10—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 halogenated hydrocarbons from polyvinyl chloride or polyvinylidene chloride
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/29—Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
  • Y10T428/2913—Rod, strand, filament or fiber
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/29—Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
  • Y10T428/2913—Rod, strand, filament or fiber
  • Y10T428/2933—Coated or with bond, impregnation or core
  • Y10T428/2964—Artificial fiber or filament
  • Y10T428/2967—Synthetic resin or polymer

Definitions

• the present invention relates to filaments, threads, fibers, monofilaments and other similar articles of synthetic material consisting essentially of atactic polyvinyl chloride, having good mechanical properties, as well as their process for obtaining.
• Polyvinyl chloride fibers are appreciated in the textile field because of certain special properties: non-flammability, resistance to light, chemical inertness and thermal, electrical and acoustic insulation power.
• ordinary polyvinyl chloride prepared by the most commonly used process at temperatures in the range of 0 to 80 ° C
• the least expensive is a normally non-crystallizable atactically predominant polymer with a transition temperature second order (Tg) of the order 65-85 ° C
• Tg transition temperature second order
• the yarns and fibers obtained from this polymer have, before shrinking, sufficient mechanical qualities for their textile transformation, (toughness of 1.60 to 2.20 cN / dtex - elongation 25-35% -module 4-5 kN / mm 2 ) but finished articles have too high a withdrawal rate (up to 60%).
• French patent 1 33845 recommends the introduction into the spinning solution of a small quantity of heavy solvent with a higher boiling point than that of the solvent or solvent mixture used for spinning of ordinary polyvinyl chloride, which makes it possible to raise the stabilization temperature of the drawn filaments and to obtain improved tenacity.
• the present invention relates to filaments, threads, fibers based on polyvinyl chloride predominantly atactic, having a modulus of elasticity greater than or equal to 2 kN / mm 2 , a residual shrinkage rate in boiling water less than 3% , an orientation index of the crystallized zones equal to or greater than 70%, that of the mesomorphic zones equal to or greater than 8%, and that of the amorphous zones equal to or greater than 5%.
• the elastic modulus is between 2 and 3.5 kN / mm 2
• the residual shrinkage in boiling water is between 1 and 2.5%
• the orientation index of the crystallized zones is between 74 and 85%, that of the mesomorphic zones between 10 and 20%, and that of the amorphous zones between 10 and 20%.
• the present invention also relates to a process for obtaining such yarns and fibers by spinning in solution in a manner known per se, drawing the filaments in boiling water at a rate of between 3 and 6 ⁇ , continuous stabilization under tension at a temperature between 105 and 130 ° C in the presence of pressurized steam, for 1 to 3 seconds then shrinking at a temperature between 98 ° and 130 ° C in an aqueous fluid medium.
• polyvinyl chloride is understood to mean the homopolymer of vinyl chloride or the copolymers containing at least 85% of vinyl chloride copolymerized with compounds comprising an ethylenic double bond, and having a transition temperature of second order included between 65 and 85 ° C.
• these copolymerizable compounds mention may be made of vinyl acetate, vinyl and methacrylic esters, acrylonitrile, vinyl compounds comprising groups capable of improving the ability of yarns and fibers to dye with respect to acid or basic dyes.
• Polyvinyl chloride as defined above is most commonly prepared in the least costly manner by mass polymerization, suspension or emulsion techniques at temperatures above 0 ° C, more generally between 20 and 60 ° C . These types of conventional polymerizations give a polymer predominantly constituted by the atactic isomer form, that is to say a polymer in which the chlorine and hydrogen atoms are predominantly located at random on both sides of the chain constituting the skeleton of the molecule. Atactic polyvinyl chloride and the products which are mainly composed thereof are of a normally non-crystallizable nature while polymers of the syndiotactic type as described in the prior art (FR-A-2161 084) are considered to be crystallizable.
• yarns and fibers based on polyvinyl chloride predominantly atactic, constituted next to the amorphous zones of a significant proportion of crystallizable or mesomorphic zones and crystallized zones, the orientation index of these three zones retaining even after retraction of the threads and fibers in an aqueous fluid medium of between 98 and 130 ° C., a level sufficient for the threads and fibers thus obtained to have markedly improved mechanical qualities, substantially at the level of those of the threads of polyvinyl chloride / superchlorinated polyvinyl chloride mixtures.
• the crystalline zone which preserves substantially the same level of orientation is made up of larger and more perfect crystals.
• the orientation index of the crystalline phases is at least 70%, more generally between 74 and 85%; that of the mesomorphic phases measured by infrared dichroism is greater than 8%, generally between 10 and 20%, and that of the amorphous zones is greater than 5%, preferably between 10 and 20%.
• the indices of the mesomorphic and amorphous zones are higher than those of the predominantly atactic polyvinyl chloride fibers known up to now.
• the orientation of the amorphous and mesomorphic phases can be determined by infrared spectrography by measuring the dichroic ratio D for defined wavelengths:
• a // is the optical density obtained in polarized light parallel to the axis of the fiber.
• a 1 is the optical density obtained in polarized light perpendicular to the axis of the fiber.
• the ratio F (D - 1) / (D + 2) is then calculated which is related to the orientation of either the amorphous zones or the zones which can be crystallized according to the wavelengths considered.
• the orientation of the amorphous zones is obtained by weighting the orientations of the isotactic and syndiotactic units:
• the modulus of elasticity is situated at a level higher than that of the yarns and fibers derived from polyvinyl chloride usually used, while the residual shrinkage in boiling water is less than 3%, preferably less than 2%.
• the fibers according to the present invention also have significantly improved elongation and toughness values which are at least at a level equal to that of fibers obtained from a mixture of polyvinyl chloride and superchlorinated polyvinyl chloride: their toughness is general of at least 16 cN / tex and can go up to 20 or 21 cN / tex or even more and their elongation is between 50 and 90%. They also unexpectedly have much better resistance to fibrillation measured by the flex-abrasion index (IFA) than standard fibers made of atactic polyvinyl chloride.
• IFA flex-abrasion index
• the yarns and fibers according to the present invention can be obtained according to any known process, for example by solution spinning according to a dry or wet process.
• Solutions can be used in known solvents or solvent mixtures such as tetrahydrofuran, or tetrahydrofuran-acetone mixtures for wet spinning; for dry spinning, the most commercially used solvents are benzene / acetone or carbon sulphide / acetone mixtures in appropriate proportions.
• the filaments are coagulated in a non-solvent bath of the polymer but miscible with the solvent whereas, according to the dry spinning process, the solvent is evaporated by means of hot air and generally recovered.
• the polymer concentration of the solutions is of the order of 20-30% by weight according to the dry spinning process and only of the order of 10-20% by weight in wet spinning; the solutions are preferably filtered before spinning to remove particles of gel or dirt likely to obstruct the orifices of the die.
• the filaments are drawn to give them a molecular orientation and improve their mechanical characteristics, at a rate of between 3 and 6 X.
• the drawing of the filaments according to the present invention comprises a preheating for example in water at temperatures between 60 and 100 ° C, more generally between 75 and 90 ° C.
• a heated water bath One practical way is to use a heated water bath.
• the actual stretching can be carried out in one or two stages, but it is preferred to gradually raise the temperature of the filaments by preheating, pre-stretching for example in a bath, the water of which can be maintained between 75 and 95 ° C.
• the filaments thus drawn are then subjected to stabilization under tension to avoid any shrinkage, in the presence of pressurized steam at a temperature between 105 and 130 ° C, preferably between 110-120 ° C for one to three seconds.
• a free retraction which can be carried out in boiling water for a variable duration, for example at least 10 minutes, in general from 10 to 20 minutes or even more or in the saturated water vapor, for example by passing through a nozzle as described in French patent n ° 83 329/1 289491.
• the filaments are treated with saturated steam at a temperature between 105 ° C and 130 ° C and are simultaneously shrunk and crimped which allows better subsequent textile workability.
• this is preferably preceded by mechanical crimping according to any known process, with the same aim of facilitating subsequent workability.
• the polymers in solutions spun according to the present application can contain usual fillers such as stabilizers, brighteners, pigments, dyes, plasticizers capable of improving some of their properties such as color, dye affinity, thermal stability, electrical resistivity, etc.
• Such a process leads to filaments with better characteristics than those of yarns based on ordinary polyvinyl chloride obtained hitherto. It makes it possible to obtain filaments at an attractive price capable of undergoing all the textile operations suitable for their finishing and of being used for the production of fabrics, knits, non-woven articles, etc. alone or in mixture with other yarns, which can undergo the usual washing and dry cleaning treatments under appropriate conditions without subsequent removal.
• a solution of predominantly atactic polyvinyl chloride (AFNOR index: 120 - chlorine level: 56.5%) is prepared in a solvent mixture of carbon sulfide / acetone, at 50/50 by volume, with a polymer concentration of 28%. .
• the solution is filtered and, while it is maintained at 70 ° C, is spun through a die of 156 mm in diameter, comprising 908 orifices of 0.06 mm in diameter each in a dry spinning cell allowing continuous recovery solvent mixture, as described in French patent 913,927.
• the filaments are then preheated in a water bath maintained at 80 ° C, then drawn a first time at a rate of 3.34 X in a water bath also maintained at 80 ° C and then drawn again in a second bath of water maintained at 97 ° C at a rate of 1.34 X (total drawing rate of 4.45 X).
• the filaments then undergo free retraction in boiling water for 20 minutes.
• the filaments thus obtained have the characteristics given in Table 1 below.
• Example 1 is reproduced in all points except the stabilization temperature in the presence of saturated steam which is maintained at 110 ° C.
• the filaments obtained have the characteristics given in Table 1 below.
• Example 1 is reproduced by only modifying the stabilization temperature of the filaments in the tube which is 120 ° C.
• Example 2 A solution identical to that described in Example 1 is prepared and it is spun in the same way through a die comprising 908 orifices with a diameter of 0.06 mm each in a dry spinning cell.
• the filaments are then preheated in a water bath maintained at 80 ° C, then undergo a first drawing in a water bath maintained at 81 ° C at a rate of 3.30 X then a second drawing in a bath maintained at 98 ° C at a rate of 1.15 X so as to obtain a total stretch of 3.8 X.
• the filaments pass continuously through a tube where they are stabilized under tension at a temperature of 105 ° C for two seconds, in the presence of steam under pressure, the entry and exit speeds into the tube being substantially equal. They are then left to retract freely in a nozzle as described in French Patent No. 83,329 / 1,289,491 in the presence of saturated steam injected at an average temperature of 120 ° C. in which they are also crimped. They have the characteristics indicated in table 2 below.
• Example 4 The procedure is as in Example 4 except the stabilization phase which is carried out at 110 ° C in the presence of steam under pressure.
• the filaments obtained after shrink in boiling water for 20 minutes have the 'characteristics given in Table 2 below.
• control filaments were spun under the conditions of Example 4 but drawn in a single stage at a rate of 3.8 X in a water bath maintained at 98 ° C and then stabilized in a water bath. boiling water at 98 ° C under tension for 10 seconds before being shrunk and curled in the nozzle described in French patent n ° 83 329/1 289491. They have the following characteristics:

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• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Artificial Filaments (AREA)
• Yarns And Mechanical Finishing Of Yarns Or Ropes (AREA)

Applications Claiming Priority (2)

Publications (2)

Family

ID=9248807

Family Applications (1)

Country Status (9)

Families Citing this family (4)

Family Cites Families (15)

• 1980
  • 1980-12-08 FR FR8026046A patent/FR2495645A1/fr active Granted
• 1981
  • 1981-10-29 DE DE8181420154T patent/DE3164221D1/de not_active Expired
  • 1981-10-29 EP EP81420154A patent/EP0053990B1/fr not_active Expired
  • 1981-12-03 CA CA000391428A patent/CA1173611A/fr not_active Expired
  • 1981-12-04 ES ES507733A patent/ES8207236A1/es not_active Expired
  • 1981-12-04 BR BR8107950A patent/BR8107950A/pt unknown
  • 1981-12-07 JP JP56196717A patent/JPS57167408A/ja active Granted
  • 1981-12-07 AR AR287718A patent/AR227451A1/es active
• 1983
  • 1983-08-12 US US06/522,746 patent/US4508778A/en not_active Expired - Lifetime
• 1986
  • 1986-05-23 US US06/870,303 patent/US4707319A/en not_active Expired - Fee Related

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