MXPA00011730A - Dyeable fluoropolymer fibers and films - Google Patents

Abstract

This invention relates to fluoropolymer fibers and films which can be modified by cationic agents, such as cationic dyes. The fiber or film comprises a blend of a first and a second copolymer, or it comprises a terpolymer, the blend or terpolymer having (1) an acid or ionic functionality provided by a pendant group represented by the formula -(O-CF2CFR)aO-CF2CFR'SO3-Z+, wherein R and R'are independently selected from F, Cl or a perfluorinated alkyl group having 1 to 10 carbon atoms, a=0, 1 or 2, and Z+ is H+, an alkali metal cation, or a cation derived from a compound selected from the group consisting of a cationic dye, a cationic whitener, a cationic flame retardant, a cationic antistatic agent, and mixtures thereof, and (2) a larger amount of a fluoroalkylvinylether, a fluoroalkene, or ethylene functionality. Such fibers and films are useful in various consumer goods where the product is desirably colored, whitened, antistatic, or flame retardant.

Description

FIBERS AND FILM DYES OF FLUOROPOLYMERS BACKGROUND OF THE INVENTION This invention relates to fluoropolymer fibers and films that are receptive to cationic modifying agents such as dyes, bleaches, antistatic agents, and flame retardants, and fibers or films that are formed by the treatment of the receptive fibers or films of the invention with this. These fibers and films are useful in various consumer products where the products are colored, bleached, desirably conferred, antistatic or flame retardant qualities. Among the properties of fluoropolymers, especially perfluorinated polymers, which make them particularly useful, are low friction, hydrophobicity, and chemical inactivity. Those same properties, however, conspire to make the dyeing of fluoropolymers problematic since several dyeing processes involve aqueous baths and sites for active dyes. As a result of these Ref: 124140 problems, it has become common practice to color fluoropolymers using pigments. In the area of fluoropolymer fibers, the pigmentation must be carried out in the molten state before the spinning of the fibers. In practice, solid pigment particles increase wear on high-precision spinning equipment, while the agglomeration of those particles interferes with the flow of the polymer. Moreover, it is known that during use, the pigmented products can undesirably transfer the pigmentation to the surface contacting them. Moreover, pigmented fibers tend to maintain a dull appearance. Similar considerations apply to the manufacture of films or sheets by molding the melt. It has long been known in the art that polytetrafluoroethylene (PTFE) in molecular weights less than c.a. 1 million exhibits excessive fragility for many practical uses. Therefore, PTFE resins are generally more useful and also today's products have molecular weights in excess of 1 million, typically 10 million, and although they exhibit a melting point, they do not serve any practical thermoplastic purpose. It has been known for many years that a durable, low molecular weight, and melt processable copolymer can be made by copolymerizing tetrafluoroethylene (TFE) with various comonomers to form copolymers containing ca. 1-10 mol-% of a branched monomeric unit. Among these comonomers are ethylene, hexafluoropropylene (HFP), and perfluoroalkyl vinyl ethers of the formula: CF2 = CF-ORf, wherein Rf is a perfluoroalkyl group such as perfluoroethyl, perfluoropropyl, or perfluorobutyl. It has been known for a long time in the art that a sulfonate functionality is added to the polyester and polyamide fibers to provide a reactive site for the cationic dyes. Also known in the art are perfluoroalkoxy sulfonyls of the formula, CF2 = CF (Rf) n-OCF2CF2S02X, where Rf is a perfluoroalkyl or perfluoroalkoxy group, n = 0 or 1, and X is F or Cl. Perfluorinated copolymers of TFE and perfluoroalkoxysulfonyl comonomer of the formula, CF2 = CF [-OCF2CF (CF3)] n-OCF2CF2S02F, wherein n is 0 or 1, and wherein the sulfonyl fluoride group is hydrolyzed to the related sulphonic acid or the sulfonate is from it has long been in widespread commercial use in the form of ion exchange membranes, such as NAFION® ion exchange membranes, available from DuPont. For various end uses, the sulfonyl portion is converted to an acid or an ionic form which is no longer capable of supporting the fusion process, but which is receptive to cationic dyes. However, it is known that the ionic form of the comonomer is highly hygroscopic, the physical properties of the resulting copolymer being highly dependent on the moisture content exhibiting considerable deterioration at high moisture levels. At concentrations of comonomers in the range that are needed to provide the ability to withstand the melting process, the fibers that are produced from the hydrolyzed receptive form of NAFION® cations are excessively sensitive to moisture and therefore are not suitable for the various potential applications.

Other TFE copolymers such as those derived from the copolymerization of TFE with a monomer containing an alkyl vinyl ether pendant group may exhibit desirable physical properties without any sensitivity to moisture, but are not receptive to cations. Connolly et al. (US Patent No. 3,282,875) discloses certain terpolymers of perfluoroalkoxysulfonyl halides, tetrafluoroethylene, and certain higher perfluoroalkyl vinyl ethers or perfluoroolefins, and methods for their synthesis. However, the molar percentages that are used by Connolly for the components of their terpolymers are designed to produce a cross-linked elastomer. US Patent 3,692,569 (see Example IX) discloses a PTFE yarn coated with a copolymer of tetrafluoroethylene and CF2 = CFOCF2CF (CF3) OCF2CF2S02F which is contacted with a solution of NaOH, followed by a rinse and dip in dilute HCl and a rinse. The resulting yarn is said to be dyed with "Sevron", a cationic dye.

Therefore, what is needed are fibers and films of fluoropolymers that are receptive to modifying agents such as dyes, bleaches, antistatic agents, and fire retardants, which retain their desirable physical and mechanical properties, and which do not have problems and deficiencies of the prior art.

Brief Description of the Invention The present invention provides a mixture comprising a first copolymer and a second "copolymer; this first copolymer comprises monomeric units of tetrafluoroethylene and a first comonomer selected from the group consisting of: a fluoroalkylvinylether, a fluoroalkene having at least three carbons, and ethylene; this second copolymer comprises monomer units of tetrafluoroethylene and a second comonomer comprises a fluoroalkenyl radical having attached thereto, a pendant group comprising a radical represented by the formula: - (0-CF2CFR) aO-CF2CFR 'Q, wherein: R and R 'are independently selected from F, Cl or a perfluorinated alkyl group having from 1 to 10 carbon atoms; a = 0, 1 or 2; Q is selected from the group consisting of: S03-Z + and -S02X; Z + is H +, an alkali metal cation, or a cation derived from a compound selected from the group consisting of a cationic dye, a cationic bleach, a cationic fire retardant, a cationic antistatic agent and mixtures thereof; X is F or Cl; this first copolymer comprises about 0.5-20 mol-% of the first comonomer; this second copolymer comprises about 5-25 mol-% of the second comonomer; and this mixture comprises about 1-10% by weight of this second copolymer. The present invention also provides a fiber or film comprising this mixture. The present invention further provides a terpolymer comprising monomeric units of a first tetrafluoroethylene termonomer; a second tercmonomer selected from the group consisting of a fluoroalkylvinylether, a fluoroalkene having at least three carbon atoms, and ethylene; and a third termonomer comprising a fluoroalkenyl radical having attached thereto a pendant group comprising a radical represented by the formula - (0-CF2CFR) aO-CF2CFR 'Q wherein: R and R' are independently selected from F, Cl or a perfluorinated alkyl group having 1 to 10 carbon atoms; a = 0, 1 or 2; Q is selected from the group consisting of: S03-Z + and -S02X; Z + is H +, an alkali metal cation, or a cation derived from a compound selected from the group consisting of: a cationic dye, a cationic bleach, a cationic fire retardant, a cationic antistatic agent and mixtures of these; and X is F or Cl; this terpolymer comprises about 0.5-5 mol-% of the second thermo- monomer and about 0.1-2 mol-% of the third termo- monomer. The present invention also provides a fiber or film comprising this terpolymer. The present invention, further provides a process for producing a shaped article, the process comprises the steps of mixing a first copolymer and a second copolymer to form a mixture, this first copolymer comprises tetrafluoroethylene monomer units and a first comonomer selected from the group consisting of fluoroalkylvinylether, a fluoroalkene having at least three carbon atoms and ethylene; and this second copolymer comprises monomeric units of tetrafluoroethylene and a second comonomer comprising a fluoroalkenyl radical having attached thereto, a pendant group comprising a radical represented by the formula - (0-CF2CFR) aO-CF2CFR'S02X wherein R and R 'are independently selected from F, Cl or a perfluorinated alkyl group having from 1 to 10 carbon atoms; a = 0, 1 or 2; and X is F or Cl; this first copolymer comprises about 0.5-20 mol-% of the first comonomer, and this second copolymer comprises about 5-25% of this second comonomer; by simultaneously heating this first and second copolymer with a subsequent mixture, at a temperature sufficient to form a molten mixture without significant degradation of any of the copolymers, this mixture comprises approximately 1-10% by weight of this second copolymer; by feeding the molten mixture to a shaping device having at least one opening, each opening is defined there by a wall; and extruding the molten mixture through at least one opening to form a shaped article. The current process may further comprise cooling the shaped article and contacting the shaped article with a solution comprising an alkali metal base to produce a shaped article receptive to the cations, and may further comprise contacting the shaped article receptive to the cations with a cationic modifying agent. The present invention also provides a process for producing a shaped article, comprising In steps of extruding a composition comprising a molten terpolymer, through at least one opening of a shaping device to form a shaped article, each opening is defined by a wall within this device, this terpolymer comprises monomer units of a first thermmonomer of ethylene tetrafluoride; a second tercmonomer selected from the group consisting of fluoroalkylvinylether, a fluoroalkene having at least three carbon atoms, and ethylene; and a third termonomer comprising a fluoroalkenyl radical having attached thereto, a pendant group comprising a radical represented by the formula (0-CF2CFR) aO-CF2CFR'S02X, wherein R and R 'are independently selected from F, Cl or a perfluorinated alkyl group having from 1 to 10 carbon atoms; a = 0, 1 c 2; and X is F or Cl; this terpolymer comprises about 0.5-5 mol-% of the second thermo- monomer and about 0.1-2 mol-% of the third termo- monomer. The process may further comprise cooling the shaped article and contacting the shaped article with a solution comprising a * 4 alkali metal base to produce a shaped article receptive to the cations, and can further comprise contacting the shaped article receptive to the cations with a cationic modifying agent.

Description of the Figures Figure 1 shows an apparatus for spinning the fibers. Figure 2 shows a cross-sectional view of an assembled spinning unit. Figure 3 shows a cross-sectional view of an assembled spinning unit, comprising a modified nozzle for spinning.

Detailed Description of the Invention The properties of chemical inactivity, hydrophobicity and high melting temperatures have prevented the development of dyeable and receptive fluorinated films and fibers to cations having useful properties. In a preferred embodiment of the present invention, the objective of the dyeability, combined with desirable physical properties, such as low sensitivity to moisture, and ability to withstand the melting process, is achieved for films and fluorinated fibers by combining a small amount of an ionic or acidic functionality from a pendant group comprising a radical represented by the formula (0-CF2CFR) aO-CF2CFR 'S03Z + with a much greater amount of a fluoroalkylvinylether functionality, a fluoroalkene, or ethylene. This combination can be achieved by mixing two PTFE copolymers, each having one of the respective functionalities, or by synthesizing a random terpolymer, which incorporates the two functionalities in the same polymer molecule. The mixture of the present invention of the two PTFE copolymers comprises a first copolymer comprising monomeric units of tetrafluoroethylene and monomer units of a first monomer selected from the group consisting of a fluoroalkyl vinyl ether, a fluoroalkene having at least three atoms of carbon, and an ethylene, and a second copolymer derived from monomeric units of tetrafluoroethylene and monomer units of a second comonomer comprising a fluoroalkenyl radical having attached thereto a pendant group comprising a radical represented by the formula: -CF2CFR) a0-CF2CFR'Q wherein R and R 'are independently selected from F, Cl or a perfluorinated alkyl group having from 1 to 10 carbon atoms; a = 0, 1 or 2; and Q is selected from the group consisting of: -S03-Z + and -S02X, wherein Z + is H +, an alkali metal cation, or a cation derived from a compound selected from the group consisting of: a dye cationic, a cationic bleach, a cationic fire retardant, a cationic antistatic agent or mixtures thereof; and X is F or Cl. By the term "comprising monomer units of" means that the copolymer is derived from the copolymerization of the selected monomers. Preferably the first comonomer is hexafluoropropylene or a perfluoroalkyl vinyl ether, preferably a perfluoroethyl- or a perfluoropropyl vinyl ether. The first comonomer is present in the first copolymer at a concentration ranging from about 0.5-20 mol-%, preferably 1-3 mol-%. Preferably the second comonomer is perfluorinated, and more preferably R is CF3, R 'is F, is already equal to 0 or 1. The second comonomer is present in the second copolymer at a concentration in the range of 5-25 mol-% , preferably 12-18 mol-%. Preferred second copolymers include, for example, the polymers described in U.S. Patent No. 3,282,875, U.S. Patent 4,538,545 and EW. U.A. 4,940,525. The equivalent weight of these second copolymers ranges from about 600 to 1,900, preferably from 900 to 1,200, wherein the equivalent weight is the weight of the resin in its acid form which neutralizes one equivalent of a base. The second most preferred comonomers are perfluoro (3-oxa-4-pentene sulfonyl fluoride) or perfluoro (3,6-dioxa-4-methyl-7-octenesulfonyl fluoride). In the mixture of the present invention, the second copolymer is present at a concentration in the range of 1-10% by weight, preferably 3-7% by weight. In order to form the mixture described above, the first and second copolymers can be in the form of tablets, powders, slurries, or whatever looks like, they are combined at room temperature when mixed or stirred together in a drum for form a mixture. If they are in the form of a slurry, the copolymer is first dried. The second comonomer, when used as a raw material to form the second copolymer, Q is -S02X. The first and second copolymers are heated, simultaneously with, or subsequently, after mixing, at a temperature sufficient to form a molten mixture without significant degradation of any copolymer. Preferably, this temperature is in the range of about 260-400 ° C. The blend of the melt can take place in a device for mixing the melt, or alternatively, the copolymers can be mixed and then fed to a melting device or to a device for shaping the melt, such as a dough spinning device melted The present invention provides a process for producing a shaped article comprising the steps of mixing the first and second copolymers described above, heating the first and second copolymers, as described above, to form a molten mixture without significant degradation of any of the copolymers, this second copolymer is present in the mixture at a concentration ranging from about 1-10% by weight; feeding the molten mixture or a shaping device having at least one opening, each opening there being defined by a wall; and extruding the molten mixture through at least one opening to form a shaped article. For certain blends, such as PSEPVE with PPVE or PEVE, it is preferred that the walls defining the openings are heated separately from the rest of the forming device. More preferably the walls are heated by thermal induction. The present process may further comprise cooling the shaped article and contacting conformed with a solution comprising an alkali metal base to form a shaped article receptive to the cations. Suitable forming devices can include a melt spinning device or an extrusion die to form a film. The shaped articles may include a fiber or a film. In the case of a fiber, so that it can be spun, the molten mixture must have a viscosity that is low enough so that the melt fracture does not occur. The temperatures suitable for use in the current process depend on the copolymers selected for use in the current process. The present process may further comprise contacting the cation-receptive shaped article with cationic modifying agents selected from the group consisting of a cationic dye, a cationic bleach, a cationic flame retardant, a cationic antistatic agent, and mixtures of these. The alkali metal base is suitable for use in the current process solution which includes aqueous solution, alcohol, DMSO solutions of NaOH, KOH, and LiOH having concentrations of ca. 1 molars. Also suitable are aqueous solutions, alcohol or DMSO of alkali metal carbonates such as Na 2 CO 3. Preferably, when forming a fiber, the opening is incorporated in the nozzle for spinning. Preferably the nozzle for spinning has a variety of openings each having a transverse dimension in the range of about 0.127 to 12.7 mm. Each opening is preferably of a round cross section, although other cross sections are also suitable. The fiber that is produced by extrusion through the nozzle for spinning can be extracted by rotation, or extracted by fusion, or not be extracted. Extraction after spinning is also an option. In a preferred embodiment, the ease of the ability to withstand the process is achieved by employing a first copolymer of TFE and HFP. The TFE / HFP copolymer and a TFE copolymer fluoride of 3,6-dioxa-4-methyl-7-octenesulfonyl (PSEVE) is melted at temperatures in the range of about 260-290 ° C. Mixtures of these copolymers can be spun conveniently into fibers at spinning nozzle temperature ranging from 300-380 ° C. When a high level of physical integrity in the fiber is required at temperatures in excess of 300 ° C, a second preferred embodiment of the present invention is a mixture of a first copolymer of TFE and perfluoropropyl vinyl ether (PPVE) with a second copolymer of TFE and PSEPVE. In a particularly preferred embodiment of the process of the present invention, 5-10% by weight of a second TFE copolymer and ca. 14 mol-% PSEPVE are melt-blended with 95-90% by weight of a copolymer of TFE and 1 mol-% of PPVE, and spun into a fiber. A TFE copolymer begins to exhibit degradation at 300 ° C, and is normally extruded from a temperature range of about 260-290 ° C. A copolymer of TFE and ca. 1 mol-% of PPVE, on the other hand, does not melt below ca. 310 ° C, and is normally extruded at ca. 350 ° C. Therefore care must be taken in maintaining the melting temperature for a mixture of these two copolymers to be as low a temperature as possible for as long as possible. In an alternative embodiment, the functionality of the mixture of the present invention is incorporated in a single polymer comprising monomeric units of a first tetrafluoroethylene thermonomer; a second tercmonomer selected from the group consisting of a fluoroalkyl vinyl ether, a fluoroalkene having at least three carbon atoms, and ethylene; and a third termonomer comprising a fluoroalkenyl radical having attached thereto a pendant group comprising a radical represented by the formula: - (0-CF2CFR) aO-CF2CFR 'Q wherein R and R' are independently selected from F, Cl or a perfluorinated alkyl group having from 1 to 10 carbon atoms; a = 0, 1 or 2; Q It is selected from the group consisting of: S03-Z + and -S02X; Z + is H +, an alkali metal cation, or a cation derived from a compound selected from the group consisting of: a cationic dye, a cationic bleach, a cationic flame retardant, a cationic antistatic agent, and mixtures thereof; X is F or Cl; this terpolymer comprises about 0.5-5 mol-% of the second thermo- monomer and about 0.1-2 mol-% of the third termo- monomer. Preferably, the terpolymer comprises tetrafluoroethylene, a second thermonomer consists of PPVE perfluoroethyl vinyl ether (PEVE), or HFP and a second comonomer comprising a fluoroalkenyl radical i having attached thereto a pendant group comprising a radical represented by the formula - (0-CF2CFR) aO-CF2CFR'S03-Z +, wherein R is trifluoromethyl, R 'is F, a is 0 or 1, more preferably 1, and Z + is H +, an alkali metal cation. The terpolymers of the present invention can be prepared using the methods described in Connolly et al (U.S. Patent 3,282,875) which are incorporated herein by reference. In general, the terpolymers of the present invention can not be spun by fusion under the same conditions that are delineated from here backwards for the mixtures of the corresponding composition. The present invention further provides a process for producing a shaped article comprising the steps of heating the terpolymer described above to a temperature sufficient to provide a molten terpolymer is a significant degradation of the terpolymer; and extruding the molten terpolymer through at least one opening of a shaping device to form a shaped article, each opening being defined within this device by a wall. For certain terpolymers, such as those comprising PSEPVE with PPVE or PEVE, it is preferred that the walls defining the openings are heated separately from the remainder of the forming device. More preferably the walls of the openings are heated by a thermal induction. The present process may further comprise cooling the shaped article and contacting the shaped article with a solution comprising an alkali metal base to form a shaped article receptive to the cations, and may further comprise contacting the shaped article responsive to the cations with a cationic modifying agent that is selected from the group consisting of a cationic dye, a cationic bleach, a cationic flame retardant, a cationic antistatic agent, and mixtures thereof. The shaping device can be the same as described above to form the mixture of the present invention in a shaped article. Preferably, the temperature to provide the molten terpolymer ranges from about 160 to 400 ° C. Also, it is preferred to have the process of the present invention that the walls defining the opening of the forming device are heated separately from the remainder of the forming device at a temperature sufficient to reduce the melting viscosity of the terpolymer in order to prevent fracture by fusion but without a significant amount of degradation. In a preferred embodiment wherein the second termonomer is vinyl ether, the walls defining the opening are heated separately from the remainder of the forming device at a temperature ranging from about 400-500 ° C. The fiber produced in this way can be extracted by rotation, or extracted by fusion, or not extracted. Extraction after spinning is an option. The fibers and films of the present invention are dyeable with cationic dyes. For example, the fibers of the present invention can be contacted with a cationic dye to provide a stained fiber. Representative examples of the cationic dyes are 5G Blue "Sevron" and Bright Red "Sevron". The Sevron dyes that are employed herein are cationic dyes that were previously manufactured by the DuPont company. The chemistry of cationic dyes is described in Chapter 8 of Color Chemistry by RLM Alien, Apple-Century-Crofts, New York, 1971. Methods for employing cationic dyes are described in Dveing First Part 3 published by the American Association of Textile Chemists and Colorists, 1981. Compounds that facilitate staining, such as a surfactant agent and / or a dye carrier can be used to dye the shaped articles of the present invention. After staining, the shaped article can be rinsed with water and then dried. The fiber of the present invention can be dyed in a single staining process separately or with other stainable cationic fibers, such as nylon or polyester, with which they can be mixed. The fibers and films of the present invention can also be modified with cationic bleaches, cationic antistatic agents, and cationic flame retardants, such as are known in the art. Figure 1 shows an apparatus useful for producing the fibers of the present invention from mixtures of terpolymers described above. For example, in order to produce fibers of the present mixture, the first and second copolymers are fed into a funnel 2 either separately as a mixture that enters through a screw extruder press 1, which is heated , wherein the copolymers form a molten mixture. This molten mixture is fed to a pump body 3 from which it is conveyed by means of a nozzle adapter for spinning 4 to the filter set 5. The filter set 5 comprises a 200 mesh screen on two mesh screens. 20, which are not shown. The molten mixture is then fed by means of a nozzle for spinning 7 to the front part of the nozzle 8 having a variety of holes. The molten mixture is extruded through the orifices of the spinning nozzle to form a multi-filament yarn 9 which is collected by drive rollers 10, which control the speed of spinning. Finally, the yarn 9 is wound on the roll of roller 11. Figure 2 shows a conventional spinning kit which is known in the art because it consists of a nozzle adapter for spinning 4 to the filter set 5 containing the wire screens. 6. The nozzle for spinning 16 consists of a hollow cylindrical member, one end of the cylinder is open, and the other end faces the nozzle 17 for spinning which has various openings through which a polymer can flow. The external surface of the cylinder has a platform 20 for coupling the internal platform 22 of the retaining nut 13 which has an internal thread 24 for coupling the external threads 26 of the nozzle adapter for spinning 4. To prevent leakage of the mass fused, metal seals of annular gaskets are provided, which are not shown, between the surfaces of the filter set 5 and the nozzle adapter for spinning 4 and between the surfaces of the filter set 5 and the nozzle for spinning 16. The height of the spinning nozzle 16 is such that the spinning nozzle 16 resides completely inside the retaining nut 13. The front face of the spinning nozzle 17 is heated by an intimate thermal contact with the retaining nut 13 which is heated by a band heater 14 that is clamped around its outer surface. By its nature, the spinning of the fibers is a highly shearing process. If the viscosity of the melt is too high, melt fracture occurs at spinning speeds too low to be practical. By keeping the melting temperature as low as possible, the degradation of both copolymers is kept to a minimum but the spinning of the fibers becomes problematic. It has been found in the practice of the invention that satisfactory results can be achieved by separately heating the face of the nozzle for spinning, and therefore the walls of the openings therein, at a temperature well above the degradation temperature. of the polymer while maintaining the other parts of the device to spin the fibers at temperatures below the temperature of the degradation. In the process of the invention, when the otherwise highly viscous molten substance reaches the hot spinning nozzle, the high ratio of surface to volume of polymer in the holes of the spinning nozzle within the face of the nozzle for spinning bears to a rapid heating, with the concomitant reduction of the melt viscosity, and therefore allows a fast performance with a highly desirable spinning speed while very little additional degradation of the polymer occurs due to the low residence time in the holes of the nozzle to spin. It is preferred in the process of the present invention that the walls within the face of the spinneret be heated to a temperature sufficient to reduce the viscosity of the melt of the mixture to prevent a melt fracture without significant degradation of the melt. copolymers. For the example of the preferred mixture of TFE / PPVE copolymers with TFE / PSEPVE, when heating the nozzle face to spin up to ca. 460 ° C while the temperature of the other parts of the shaping device, such as the extruder and filter set, is required at a temperature of about 350 ° C is effective. Preferably, the temperature ranges from about 400-500 ° C for this selection of copolymers in particular. Figure 3 shows a preferred spinning game design for use in the practice of the present invention. All of its parts are substantially the same as in Figure 2 with the exception that the spinning nozzle 7 is elongated such that a portion of the spinning nozzle 7 projects from the retaining nut 13 and the nozzle face for spinning 8 it is located outside the holding nut 13, furthermore, the face of the nozzle for spinning 8 is heated independently by means of a heater 12 which allows a higher temperature for the face of the nozzle 8 than the one which is subjected to the rest of the game to spin. This invention is further described by the following specific embodiments.

Example 1 Five parts by weight of pellets of a TFE / PSEPVE copolymer containing ca. 16 mol-% of the PSEPVE containing the comonomer, available as NAFION® resin XR, of the company DuPont Company, Wilmington DE (equivalent weight 1064, 11.5 speed of fusion flow to 270 ° C) are mixed by stirring in a spin drum at room temperature with 95 parts by weight of resin pellets of the PFA copolymer, Teflon® PFA 340, available from DuPont, containing 1.0 mol-% of the PFA containing the comonomer and with a melt flow index of 14.7 to form 1,500 grams of a mixture of pellets. The mixture is fed to a melt spinning apparatus, substantially as shown in Figure 1, which contains a single screw extruder press of 19.0 mm with an L / D of 35, manufactured by Wayne Machine & Die Co., 100 Furier St., Totowa, NJ 07512-9973, with all controls and pump body added by DuPont.

The set of filters has a mesh-200 screen on two screens of mesh-20. The tuff for spinning is extended to 50. 8 mm to the face of the tuff for spinning which has 39 I! holes. The holes of the spinning tuff are 0.762 mm in diameter and round and with an L / D of 1. 0. Then the yarn is wrapped in a Lessona Model 959, i Lessona Corporation Warwick, Rhode Island. The temperature from the extruder, to the set of filters, is set at 350 ° C, and the same tuff for spinning 460 ° C. At the same extrusion rate of 21.2 grams per minute with a filament pressure jet velocity of 0.795 m per minute (m / min), the maximum speed of the drag rollers is 340 m / min before a first break of the filament and the spin-stretched factor (SSF) is 428. The yarn has a denier of 561 with a single filament of 12 dpf and a diameter of 28.3 microns. The tenacity of the filament is 1. 18 gpd, with 31% elongation hiasta the rupture.

EXAMPLE 2 The conditions of Example 1 are repeated except that the dragging and winding speeds decelerate to 20 m / min, whereby a good packet of yarn is obtained during 18 min, without any broken filament. The net weight of the yarn package with a denier of 954 is 365 grams. The dpf of the filament is 23, the tenacity of 0.56 gpd, and the elongation to rupture of 58%. Approximately 1.0 gram of the fiber skein is boiled as spun in Example 2 in a 250 ml Erlenmeyer glass flask on a hot plate containing 150 ml of a water solution with 10% sodium hydroxide for about 20 minutes. minutes and then it is rinsed with natural water and then with soft water. Excess water in the hydrolysed fiber is removed by patting it between two paper towels. The fiber has the same white appearance as before the hydrolysis. The fiber that is dried by tapping is immersed in a dye bath containing a very small amount of a cationic dye (Brilliant Red "Sevron", DuPont Co.) and the typical compounds to facilitate the .-. . staining such as a surfactant agent and a dye carrier, and boiling for about 15 minutes. After staining, the fiber is rinsed with natural water and dried in air. A second sample of similar fiber size of Example 2 is stained blue when using a staining bath with 5G Blue "Sevron". The unhydrolyzed control groups are also analyzed to verify their stainability. The unhydrolyzed controls show a slight hint of red or blue while the hydrolyzed samples display a strong hue of red or blue.

Comparative Example 1 This Example demonstrates that the temperature of the melt must be maintained in such a manner as to prevent melt fracture and fracture. The equipment and materials of Example 1 are used. The temperature of the extruder is 350 ° C, the body of the filter set is set at 400 ° C, and the nozzle for spinning at 460 ° C. The extrusion rate is 22.1 grams per minute with a filament jet velocity of 0.795 meters per minute (m / min) and the yarn formed is thus taken up by the drag rollers at a maximum speed of only 170 m / min when a first filament is broken from the nozzle to spin. The resulting drawing speed is a stretch factor during spinning of 239 (SSF). The multi-filament yarn has a denier of 1, 006 with an individual denier of 25.8 and a diameter of 41.5 microns. The extruded filament has the appearance of transparent and pervading beads, signs of a thermal degradation of the Nafion® XR resin. When the temperature profile is reduced to 350 ° C from the extruder to the set of filters, and at 400 ° C in the nozzle for spinning, the fusion fracture occurs.

It is noted that in relation to this date, the best known method for the applt to carry out the aforementioned invention, is the conventional one for the manufacture of the objects or products to which it refers.

Claims (14)

CLAIMS Having described the invention as above, the content of the following claims is claimed as property:

1. A fiber, characterized in that it comprises a mixture comprising: a first copolymer and a second copolymer; this first copolymer comprises monomeric tetrafluoroethylene units and a first comonomer selected from the group consisting of: a fluoroalkylvinylether, a fluoroalkene having at least three carbon atoms, and ethylene; this second copolymer comprises tetrafluoroethylene monomer units and a second comonomer comprising a fluoroalkenyl radical having attached thereto, a pendant group comprising a radical represented by the formula: - (0-CF2CFR) aO-CF2CFR 'Q, wherein : R and R 'are independently selected from F, Cl or a perfluorinated alkyl group having from 1 to 10 carbon atoms; a = 0, 1 or 2; Q is selected from the group consisting of: -S03-Z + and -S02X; Z + is H +, an alkali metal cation, or a cation derived from the compound selected from the group consisting of a cationic dye, a cationic bleach, a cationic flame retardant, a cationic antistatic agent and mixtures thereof; X is F or Cl; this first copolymer comprises about 0.5-20 mol-% of the first comonomer; this second copolymer comprises about 5-25 mol-% of the second comonomer; and this mixture comprises about 1-10% by weight of this second copolymer.

2. The fiber according to claim 1, characterized in that the first comonomer is hexafluoropropylene, perfluoropropylvinylether, or perfluoroethylvinyl ether, and the second comonomer is represented by the formula CF2 = CF- (OCF2CF- (CF3)) aOCF2CF2S03-Z +, wherein a = 0 or 1.

3. The fiber according to claim 2, characterized in that Z + is the cationic dye.

4. A fiber, comprising a terpolymer, characterized in that it comprises: monomer units of: a first tetrafluoroethylene termonomer; a second termmonomer selected from the group consisting of: a fluoroalkylvinylether, a fluoroalkene having at least three carbon atoms, and ethylene; and a third termonomer comprising a fluoroalkenyl radical that is linked to a pendant group comprising a radical represented by the formula - (0-CF2CFR) aO-CF2CFR 'Q, wherein: R and R' are independently selected from F, Cl or a perfluorinated alkyl group having from 1 to 10 carbon atoms; a = 0, 1 or 2; Q is selected from the group consisting of: S03-Z + and -S02X; Z + is H +, an alkali metal cation, or a cation derived from the compound selected from the group consisting of a cationic dye, a cationic bleach, a cationic flame retardant, a cationic antistatic agent and mixtures thereof; and X is F or Cl; this terpolymer comprises about 0.5-5 mol-% of the second thermo- monomer and about 0.1-2 mol-% of the third termo- monomer.

5. The fiber according to claim 4, characterized in that the second thermonomer is perfluoropropylvinylether, perfluoroethylvinyl ether, or hexafluoropropylene, and the third thermonomer is CF2 = CF- (OCF2CF (CF3)) aOCF2CF2S03-Z +, where a = 0 or 1

6. The fiber according to claim 5, characterized in that Z + is the cationic dye.

7. A process for producing a fiber, characterized in that the process comprises the steps of: mixing a first copolymer and a second copolymer to form a mixture, this first copolymer comprises tetrafluoroethylene monomer units and a first comonomer selected from the group consisting of fluoroalkylvinylether , a fluoroalkene having at least three carbon atoms, and an ethylene; and this second copolymer comprises tetrafluoroethylene monomer units and a second comonomer comprising a fluoroalkenyl radical having attached thereto, a pendant group comprising a radical represented by the formula - (0-CF2CFR) aO-CF2CFR 'S02X wherein R and R 'are independently selected from F, Cl or a perfluorinated alkyl group having from 1 to 10 carbon atoms; a = 0, 1 or 2; and X is F or Cl; this first copolymer comprises about 0.5-20 mol-% of the first comonomer, and this second copolymer comprises about 5-25% of monomeric units of this second comonomer; heating this first and second copolymer, simultaneously or subsequently to the mixture, at a temperature sufficient to form a molten mixture without significant degradation of any copolymer, this mixture comprises about 1-10% by weight of this second copolymer; feeding the molten mixture to a spinning device of the melt having a spinning nozzle having at least one opening, each opening being defined there by a wall; extruding the molten mixture through at least one opening to form a fiber.

8. The process according to claim 7, characterized in that it further comprises cooling the fiber and contacting the fiber with a solution comprising an alkali metal base to produce a cation-receptive fiber.

9. The process according to claim 8, characterized in that it further comprises contacting the receptive cation fiber with a cationic modifying agent selected from the group consisting of: a cationic dye, a cationic bleach, a cationic flame retardant, a cationic antistatic agent, and mixtures thereof.

10. A process for producing a fiber, characterized in that it comprises the steps of: extruding a composition comprising a molten terpolymer through at least one opening of a spinning nozzle of a spinning device to form a fiber of the melt, each aperture is defined by a wall within this spinneret, this terpolymer comprises monomer units of a first thermonomer of ethylene tetrafluoride; a second tercmonomer selected from the group consisting of fluoroalkylvinylether, a fluoroalkene having at least three carbon atoms, and ethylene; a third termonomer comprising a fluoroalkenyl radical having attached to this pendant group comprising a radical represented by the formula - (0-CF2CFR) aO-CF2CFR'S02X, wherein R and R 'are independently selected from F, Cl or a perfluorinated alkyl group having from 1 to 10 carbon atoms, a = 0, 1 or 2; and X is F or Cl; this terpolymer comprises about 0.5-5 mol-% of the second thermo- monomer and about 0.1-2 mol-% of the third termo- monomer. ^ -ria s 5 & J ~ $ c

11. The process according to claim 10, characterized in that it further comprises cooling the fiber and contacting the fiber with a solution comprising an alkali metal base to produce a cation receiving fiber.

12. The process according to claim 11, characterized in that it further comprises contacting the cation receptive fiber with a modifying agent selected from the group consisting of: a cationic dye, a cationic bleach, a cationic flame retardant, a cationic antistatic agent, and mixtures thereof.

13. The process according to claim 7 or 10, characterized in that there are a variety of openings and the walls defining the openings are heated separately from the rest of the spinning device of the melt, at a temperature in the range of about 400 to approximately 500 ° C.

14. The process according to claim 9 or 12, characterized in that before contacting the cationic dye, the cation receptive fiber is mixed with a second stainable fiber.