MXPA99008303A - Procedure for manufacturers filaments of crystalline crystalline liquids, high-numerous deniers, and compositions - Google Patents

Abstract

The present invention describes and claims a novel process for the formation of filaments as they are spun and heat treated of the high denier number of a thermotropic liquid crystalline polymer, preferred embodiments include the process for the formation of monofilaments as they are spun and heat treated from some fully aromatic polyesters and polyesteramides, the process involves heating the thermotropic liquid crystalline polymer above its melting transition temperature, passing said melting polymer through an extrusion chamber equipped with an extrusion capillary an aspect ratio greater than about 1 and less than about 15 to form a filament, and winding the filament at an extension ratio of at least about 4, the filaments formed in this way are at least 50 deniers per filament and one filament molecular orientation essentially uni formed in the cross section, in an optional final step, the filaments are heat treated in stages to form filaments that show excellent tensile properties, the filaments as they are spun and heat treated show considerably good hold properties retaining at least 80 to 90% of the expected properties of the filaments of low number of conventional deniers, 5 to 10 d

Description

PROCEDURE FOR MANUFACTURING POLYMER FILAMENTS HIGH NUMBER OF THERMOTROPIC LIQUID CRYSTALS DENIERS. AND COMPOSITIONS FOR THE SAME BACKGROUND OF THE INVENTION FIELD OF THE INVENTION The present invention relates to methods for forming filaments of a thermotropic liquid crystalline polymer. Specifically, the present invention provides methods for forming filaments of a high number of deniers, heat treated and as spun, of a variety of fully aromatic, thermotropic liquid crystalline polyesteramides and polyesters. This invention also relates to filaments of polyesteramides and thermotropic liquid crystalline polyesters of high denier number, heat treated and as spun.

DESCRIPTION OF THE PREVIOUS TECHNIQUE Thermotropic liquid crystalline polymers (LCPs) are an important group of polymers, which are usually fully aromatic molecules that contain a variety of heteroatom linkages that include ester and / or esteramide linkages. After heating at sufficiently high temperature, the LCPs melt to form a phase of liquid crystalline melt (often referred to as an "anisotropic phase"), rather than an isotropic melt. Generally, LCPs consist of linear molecules ("rigid rod") that can be aligned to produce the order of the desired liquid crystalline material. As a result, the LCPs exhibit low viscosity of the molten material and thus improved performance and process capabilities. Because LCPs are oriented to form linear "rigid rod" molecules, LCPs exhibit mechanical properties extremely high. In this way, it is well known in the art that LCPs can be formed into shaped articles, such as films, rods, tubes, fibers, and various other molded articles. Furthermore, it is also known in the art that LCPs, particularly in the form of fiber, exhibit exceptionally high mechanical properties after a * f- 15 heat treatment procedure. However, all methods known in the art describe the formation of only fibers of low number of deniers, for example, of about 10 deniers per filament (dpf), which exhibit high mechanical properties in their heat treated forms and such as they are spun In this way, an object of the present invention is to provide a method for forming LCP filaments of high number of uniformly oriented deniers. A filament with a high number of deniers means a filament of more than 50 dpf.

It is also an object of the present invention to provide a method for forming LCP filaments of more than 50 dpf, which exhibit improved mechanical, thermal and chemical resistance properties in the heat treated and spun form. It is further an object of the present invention to provide a method for forming LCP filaments of high number of deniers, which exhibit properties comparable to those of the LCP filaments of low number of deniers (ie, filaments of less than 10 dpf) in its conditions treated with heat and as they are spun. It is also an object of the present invention to provide LCP filaments of high number of deniers of more than 50 dpf having properties comparable to those of LCP filaments of low number of deniers of less than 10 dpf. Finally, an object of the present invention is to provide an industrially economical and cost effective way to heat treat the high denier filaments of this invention, directly on the coil to produce filaments of high denier number of mechanical properties and superior physics. There is a great convenience for forming LCP filaments of high number of uniformly oriented deniers, which exhibit improved mechanical, thermal and chemical resistance properties in the heat treated and spun form. For example, high density denier LCP filaments can replace steel cords on steel belt tires. In addition, since the LCP filaments are of substantially lower density compared to steel cords, it is expected that the LCP filaments exhibit properties much superior to those exhibited by the steel cords. It is also obvious from the prior art that there is a real need for LCP filaments of high denier number that exhibit improved mechanical, thermal and chemical resistance properties.

PREVIOUS TECHNIQUE The following references are described as antecedent prior art. The patent of E.U.A. No. 4,183,895 discloses a process for treating polymeric products that form aniopic melt material. A heat treatment process allowed to have fibers having improved mechanical properties, and the tenacity of the fiber was increased by at least 50% and up to at least 10 grams per denier. The patent of E.U.A. No. 4,468,364 describes a process for extruding thermotropic liquid crystalline polymers (LCPs). It is claimed that by extruding a LCP through the orifice of a die having a L / D ratio of less than 2 (preferably 0), and at a stretch rate less than 4 (preferably 1), filaments can be obtained which show high mechanical properties The patent of E.U.A. No. 4,910,057 discloses a highly elongated member of substantially uniform cross-sectional configuration, which is capable of providing enhanced service as a reinforcement support in a fiber optic cable. The patent of E.U.A. No. 5,246,776 discloses an aramid monofilament and a method for obtaining same. The patent of E.U.A. No. 5,427,165 discloses a reinforcing assembly formed at least in part from continuous monofilaments of liquid crystalline organic polymer (s). The polymers used therein are mainly aramides. Japanese Patent Laid-open No. 4-333616 discloses a method for making filaments from 50 to 2000 dpf from molten liquid crystalline polymers. The mechanical properties of these heat-treated filaments were significantly lower than the properties reported for filaments of 5 to 10 dpf with fewer corresponding deniers. Reference J. Rheology 1992, Vol. 36 (p.1057-1078) reports a study of the rheology and orientation behavior of a thermotropic liquid crystalline polyester using capillary dies of different aspect ratios. The reference J. Appl. Polym. Sci. 1995, Vol 55 (p 1489-1493) reports the orientation distribution in extruded rods of thermotropic liquid crystalline polyesters. The orientation function increases with the increasing apparent shear rate of 166 to 270 sec "1, but decreases with the apparent apparent shear rate of 566 to 780 sec." All references described herein are incorporated in their entirety in the same as reference.

BRIEF DESCRIPTION OF THE INVENTION It has now been unexpectedly and surprisingly found that filaments of high denier number, heat treated and as spun, of at least 50 denier per filament can be obtained which show essentially uniform molecular orientation through its cross section. In addition, these high denier filaments show remarkably good tensile properties which retain at least 80 to 90% of the expected properties of the filaments of low number of conventional deniers, ie, 5 to 10 dpf, which was up to now unreachable by any of the known references of the prior art, as briefly described above. Thus, in accordance with this invention, there is provided a method for forming a filament such as spun, of a thermotropic liquid crystalline polymer having the following properties: (i) deniers of at least about 50 deniers per filament; (I) tenacity of at least about 8 grams per denier; (iii) module of at least about 450 grams per denier; and (iv) elongation of at least about 2%. The process of the present invention is formed of the following steps: (a) heating a thermotropic liquid crystalline polymer at a temperature of at least about 15 ° C above its transition to melting to form a fluid stream of said polymer thermotropic; (b) passing said current through a heated extrusion chamber, wherein said chamber is disposed with a suitable cylindrical orifice to form the filament of said polymer, and wherein said cylindrical orifice has an aspect ratio of length: diameter (L / D) greater than about 1 and less than about 15; and (c) winding said filament at a winding speed of at least about 200 meters per minute and at a stretch rate (D / D) of at least about 4; and with the proviso that when L / D is between 0 and 2, the DD is at least 4 to form the filament of essentially uniform molecular orientation through its cross section, and having a denier value of at least approximately 50 deniers per filament.

In another aspect of the invention, there is also provided a method for forming a heat treated filament of a thermotropic liquid crystalline polymer having the following properties: (i) denier of at least about 50 deniers per filament; (ii) tenacity of at least about 20 grams per denier; (iii) module of at least about 600 grams per denier; and (v) elongation of at least about 3%. Thus, in accordance with this aspect of the present invention, the method is comprised of the following steps: (a) heating a thermotropic liquid crystalline polymer at a temperature of about 15 ° C to about 50 ° C above its transition to the melt to form a fluid stream of said polymer; (b) extruding said polymer stream through a heated cylindrical spinner having at least one extrusion capillary to form a filament, wherein said capillary has an aspect ratio of length: diameter (L / D) on the scale from about 1 to about 10; (c) winding said filament at a winding speed of at least about 200 meters per minute and at a stretch ratio of about 5 to about 40, to form a filament of essentially uniform molecular orientation through the cross section, and having a value in deniers on the scale of about 50 to about 1000 deniers per filament; and (d) heat treating said filament at suitable temperature and pressure conditions for a sufficient period, optionally in the presence of an inert atmosphere, to form the heat treated filament. In yet another aspect of this invention, a filament such as is spun, of a thermotropic liquid crystalline polymer is also provided. In a further aspect of this invention, there is also provided a heat-treated filament of a thermotropic liquid crystalline polymer. In another embodiment of this invention, a method is also provided to heat treat the high denier filaments of this invention directly on the coil on which they were wound while rotating. Other aspects and advantages of the present invention are further described in the following detailed description of the preferred embodiments thereof. Examples of the aromatic-aliphatic polyesters and polyesteramides that can be used to practice the invention, can include those having the following structures: II is II is You see VI is Vil is Viles - ° M - DETAILED DESCRIPTION OF THE INVENTION In accordance with this invention, there is provided a process for forming a filament of a thermotropic liquid crystalline polymer having the following properties: (i) deniers of at least about 50 deniers per filament; (ii) tenacity of at least about 8 grams per denier; (Ii) module of at least about 450 grams per denier; and (iv) elongation of at least about 2%. The process of the present invention is formed of the following steps: (a) heating a thermotropic liquid crystalline polymer at a temperature of at least about 15 ° C above its transition to melting to form a fluid stream of said thermotropic polymer; (b) passing said current through a heated extrusion chamber, wherein said chamber is disposed with a suitable cylindrical orifice to form the filament of said polymer, and wherein said cylindrical orifice has an aspect ratio of length: diameter (L / D) greater than about 1 and less than about 15; and (c) winding said filament at a winding speed of at least about 200 meters per minute and at a stretch rate (D / D) of at least about 4; and with the condition that when L / D is between 0 and 2, the DD is at least 4 to form the filament of essentially uniform molecular orientation through its cross section, and having a denier value of at least about 50 deniers per filament. As described above, the references of the prior art describe various methods for the manufacture of filaments of thermotropic polymers, including filaments of high number of deniers. A specific example of a method for preparing filaments of high number of deniers is described in the patent of E.U.A. No. 4,468,364, which is hereby incorporated by reference in its entirety. In this work, the thermotropic polymers were extruded from jets of greater diameter to low stretches, which automatically gave thicker filaments. The molten material of the polymer was also extruded at low yields, ie at low polymer velocity in the jet, and the filaments were wound at low speed. This means that most of the orientation of the filament is obtained from the convergent flow in the jet itself, which explains why the increase in the length of the capillary causes the orientation to decrease, that is, the orientation module or of filament. The passage of the polymer through the capillary before leaving the jet will cause disorientation of the flow, which had been induced by the converging part of the jet above the capillary. Unlike the conditions of the prior art process described above, the method of the present invention operates at greater stretches, with the result that the filament undergoes elongation to decrease the diameter thereof once it emerges from the jet orifice. This elongation flow locates most of the orientation in the filament, thus providing a filament having essentially uniform cross-sectional orientation. In addition, the present invention also provides a commercially practical process in which the performance of the polymer can be increased. Because the pressure on the jet will increase linearly with the performance, the pressure will reach unrealistic levels for small jets. In accordance with the process of the present invention, the preferred polymers are thermotropic liquid crystalline polymers. Thermotropic liquid crystalline polymers are polymers that are crystalline and liquid (ie, anisotropic) in the phase of molten material. Thermotropic liquid crystalline polymers include fully aromatic polyesters, aromatic-aliphatic polyesters, aromatic polyazomethines, aromatic polyesteramides, aromatic polyamides and aromatic polyester carbonates. The aromatic polyesters are considered to be "fully" aromatic in the sense that each portion present in the polyester contributes at least one aromatic ring to the base structure of the polymer.

Specific examples of suitable aromatic-aliphatic polyesters are copolymers of polyethylene terephthalate and hydroxybenzoic acid, as described in Polyester X7G-A Self Reinforced Thermoplastic, by W. J. Jackson Jr., H. F. Kuhfuss and T. F. Gray Jr., 30th Anniversary Technical Conference, 1975 Reinforced Plastics / Composites Institute, The Society of the Plastics Industry, Inc., Section 17-D, p. 1-4.

A further description of said copolymer can be found in "Liquid Crystal Polymers: I. Preparation and Properties of p-Hydroxybenzoic Acid Copolymers, "Journal of Polymer Science, Polymer Chemistry Edition, Vol 14, pp. 2043-58 (1976), by WJ Jackson Jr. and HF Kuhfuss, The references cited above are hereby incorporated by reference in their entirety as aromatic and aromatic polyazomethines. Methods for preparing them are described in U.S. Patent Nos. 3,493,522, 3,493,524, 3,503,739, 3,516,970, 3,516,971, 3,526,611, 4,048,148 and 4,122,070, each of which is hereby incorporated by reference in its entirety. said polymers include poly (nitrile-2-methyl-1,4-phenylene-nitriloethylidene-1,4-phenylene-ethylidene); poly (nitrile-2-methyl-1,4-phenylene-nitrilomethylidino-1,4-phenylene-methylidene); poly (nitrile-2-chloro-1,4-phenylene-nitrilomethylidino-1,4-phenylene-methylidene) Aromatic polyesteramides are described in U.S. Patent Nos. 5,204,443, 4,330,457, 4,966,956, 4,355,132, 4,339,375, 4,351, 917 and 4,351, 918. Each one of these patents and fully incorporated herein by reference. Specific examples of such polymers include polymers formed from the monomers comprising 4-hydroxybenzoic acid, 2,6-hydroxynaphthoic acid, terephthalic acid, 4,4'-biphenol and 4-aminophenol; and polymers formed from the monomers comprising 4-hydroxybenzoic acid, 2,6-naphthalenedicarboxylic acid, terephthalic acid, soft-gel acid, hydroquinone and 4-aminophenol. Preferred aromatic polyamides are those which are processable molten material and form thermotropic melt phase, as described above. Specific examples of such polymers include polymers formed from monomers comprising terephthalic acid, isophthalic acid and 2,2'-bis (4-aminophenyl) propane. Aromatic polyester carbonates are described in the U.S.A. No. 4,107,143, which is incorporated herein by reference in its entirety. Examples of such polymers include those consisting essentially of hydroxybenzoic acid units, hydroquinone units, carbonate units and aromatic carboxylic acid units. Preferred liquid crystalline polymers for use in the process of the present invention are fully aromatic thermotropic polyesters. Specific examples of said polymers can be found in the patents of E.U.A. Nos. 3,991,013; 3,991, 014; 4,057,597; 4,066,620; 4,075,262; 4,118,372; 4,146,702; 4,153,779; 4,156,070; 4,159,365; 4,169,933; 4,181, 792; and 4,188,476, and the application of United Kingdom No. 2,002,404. Each of these patents is hereby incorporated by reference in its entirety. The fully aromatic polyesters that are preferred for use in the present invention are described in the U.S. Patents. commonly assigned Nos. 4,067,852; 4,083,829; 4,130,545; 4,161, 470; 4,184,996; 4,238,599; 4,238,598; 4,230,817; 4,224,433; 4,219,461; Y 4,256,624. The descriptions of all patents and applications of E.U.A. commonly assigned identifiers, are hereby incorporated by reference in their entirety. The fully aromatic polyesters described herein are typically capable of forming an anisotropic melt phase at a temperature of less than about 350 ° C. The fully aromatic polyesters which are suitable for use in the process of the present invention can be formed by various ester forming techniques, whereby organic monomeric compounds having functional groups are made which, after condensation, form the required recurring portions. For example, the functional groups of the organic monomeric compounds can be carboxylic acid groups, hydroxyl groups, ester groups, acyloxy groups, acid halides, etc. The organic monomeric compounds can be reacted in the absence of a heat exchange fluid by a process of acidolysis of molten material. Accordingly, they can be initially heated to form a solution of molten material from the reactants, the reaction continuing as the solid polymer particles are suspended therein. A vacuum can be applied to facilitate the removal of volatile compounds formed during the final stage of condensation (eg, acetic acid or water). In the patent of E.U.A. commonly assigned No. 4,083,829, entitled "Melt Processable Thermotropic Wholly Aromatic Polyester", describes a suspension polymerization process, which can be used to form the fully aromatic polyesters that are preferred for use in the present invention. According to said method, the solid product is suspended in a heat exchange medium. The description of this patent has previously been incorporated herein in its entirety as a reference. When the process of acidolysis of molten material or the suspension procedure of the patent of E.U.A. No. 4,083,829, the organic monomer reagents from which the fully aromatic polyesters are derived may be initially provided in a modified form, whereby the usual hydroxy groups of said monomers are esterified (ie, provided as lower acyl esters) ). The lower acyl groups preferably have from about two to about four carbon atoms. Preferably, the acetate esters of organic monomer reagents are provided.

Representative catalysts which may optionally be used in the process of acidolysis of molten material or in the suspension process of the patent of E.U.A. No. 4,083,829, include dialkyl tin oxide (for example, dibutyl tin oxide), diaryl tin oxide, titanium dioxide, antimony trioxide, alkoxy titanium silicates, titanium alkoxides, alkali metal and alkali metal salts of carboxylic acids (e.g., zinc acetate), gaseous acid catalysts such as Lewis acids (e.g., BF3), hydrogen halides (e.g., HCl), and similar catalysts known to those skilled in the art. The amount of catalyst used is typically from about 0.001 to about 1% by weight based on the total weight of the monomer, and more commonly from about 0.01 to about 0.2% by weight. The fully aromatic polyesters that are preferred for use in the present invention commonly show a weight average molecular weight of from about 10,000 to about 200,000, and preferably from about 20,000 to about 50,000 (eg, about 30,000 to about 40,000). Said molecular weight can be determined by commonly used techniques, such as mediations of gel permeation chromatography or solution viscosity. Other methods include the determination of the external group by infrared spectroscopy in compression molded films or spectroscopic measurements of nuclear magnetic resonance (NMR) of polymer solutions or NMR in solid phase of powder or polymer films. Alternatively, light scattering techniques in a pentafluorophenol solution can be used to determine the molecular weight. The fully aromatic polyesters or polyesteramides additionally commonly exhibit an inherent viscosity (i.e., I.V) of at least 2.0 dL / g for example, about 2.0 to about 10.0 dL / g, when dissolved in a concentration of 0. 1% by weight in a 1: 1 hexafluoroisopropanol solvent mixture (HFIPypentafluorophenol (PFP) (v / v) at 25 ° C. The polymers especially preferred for the process of the present invention are fully aromatic polyesters and polyesteramides.

In preferred embodiments of the present invention, the specifically preferred polyesters are listed below: a) The fully aromatic polyester capable of forming an anisotropic melt phase at a temperature below about 350 ° C consists essentially of recurring portions I and II where: is I I is The fully aromatic polyester, as described above, is described in U.S. Patent No. 4,161,470. The polyester comprises from about 10 to about 90 mole percent of a portion I, and from about 10 to about 90 mole percent of the portion II. In one embodiment, portion II is present at a concentration of about 65 to about 85 mole percent, and preferably at a concentration of about 70 to about 80 mole percent; for example, approximately 75 percent in moles. In another embodiment, portion II is present in a minor proportion of about 15 to about 35 mole%, and preferably at a concentration of about 20 to about 30 mole percent. b) The fully aromatic polyester capable of forming an anisotropic melt phase at a temperature below 400 ° C consists essentially of the recurring portions I, II, III, and IV where: I is l l l is I saw him The polyester comprises from about 40 to about 60 mole percent of the portion I, from about 2 to about 30 percent of the portion II, and from about 19 to about 29 mole percent of each of the portions III and VII. In one of the preferred modalities, the polyester comprises from about 60 to about 70 mole percent of the portion I, from about 3 to about 5 mole percent of the portion II, and from about 12.5 to about 18.5 mole percent of each of the portions III and Vile. The preferred polyesteramides of the process of the present invention are summarized below: a) The fully aromatic polyesteramide capable of forming an anisotropic melt phase at a temperature below 360 ° C consists essentially of the recurring portions II, I and VI where: II is I is and V I is The fully aromatic polyesteramide, as described above, is described in U.S. Patent No. 4,330,457, which is incorporated herein by reference in its entirety. The polyesteramide comprises from about 25 to about 75 mole percent of portion II, and from about 37.5 to about 12.5 mole percent of each of portions I and VI. The polyesteramide preferably comprises from about 40 to about 70 mole percent of portion II, and from about 15 to about 30 mole percent of each of portions I and VI. In one of the preferred embodiments of the invention, the polyesteramide comprises from about 60 to about 65 mole percent of the portion II, and from about 17.5 to about 20 mole percent of each of the portions I and VI. b) The fully aromatic polyesteramide capable of forming an anisotropic melt phase at a temperature below about 380 ° C consists essentially of the recurring portions I, II, III, VII and VI where: is Vil is VI is 20 The fully aromatic polyesteramide, as described above, is described in U.S. Patent No. 5,204,443, which is hereby incorporated by reference in its entirety. The polyesteramide comprises from about 40 to about 70 mole percent of the portion I, from about 1 to about 20 mole percent of the portion II, from about 14.5 to about 40 mole percent of the portion III, from about 7 to about 27.5 mole percent of the VII portion, and from about 2.5 to about 7.5 mole percent of the VI portion. c) The fully aromatic polyesteramide capable of forming an anisotropic melt phase at a temperature below about 350 ° C consists essentially of the recurring portions I, II, III, IV, V, and VI where: I is is l l l is I V is You see V I is The polyesteramide, as described above, comprises from about 40 to about 70 mole percent of portion I from about 10 to about 20 mole percent of portion II, from about 2.5 to about 20 mole percent of portion III, from about 0 to about 3 mole percent of the IV portion, from about 12.5 to about 27.5 mole percent of the V portion and from about 2.5 to about 7.5 mole percent of the VI portion. In accordance with the process of the present invention, a fluid stream of liquid crystalline polymer is provided to any conventional extruder apparatus. The above is achieved by heating the thermotropic liquid crystalline polymer of the present invention to form a melt. Any of the known methods for heating the polymer to form a melt can be employed in the following invention. The particular apparatus used is not critical to the operation of the method of the present invention, and any suitable apparatus can be used herein. Once it has been discovered that said apparatus is suitable for use with the liquid thermotropic liquid polymers, a contact fusion method is employed so that the residence time of fusion can be kept short and constant. The apparatus includes a heating surface against which a molded liquid crystal polymer rod is pressed. The fluid stream of the fused polymer is then introduced into the extruder chamber within which a filter gasket and a cylindrical orifice are disposed. After having passed through the filter package, the polymer melt is extruded through the cylindrical orifice.

In a preferred embodiment, the extrusion chamber is comprised of a single orifice cylindrical chamber in which the polymer is heated to a temperature in the range of about 20 ° C to about 50 ° C above its melting transition point . In said preferred embodiment, the cylindrical orifice having an aspect ratio (L / D) of about 1 to about 10 is used.

As used herein, the aspect ratio is intended to define the ratio of length (L) to diameter (D) of the cylindrical orifice. In a more preferred embodiment of said invention, the aspect ratio of the cylindrical orifice is in the range of about 1 to about 3. After the fluid stream of the liquid crystal polymer is extruded through the orifice, the polymer forms a elongated shaped article having the polymer molecules oriented substantially parallel to the direction of flow. The orientation of the polymer molecules can be shaped by determining the orientation angle by X-ray analysis. The articles of extruded form in the form of filaments are then stretched and wound on a filament spool. In accordance with the method of the invention, it is important that the proper stretch ratio is used to exploit the maximum benefit of the practice of the present invention. Thus, in a preferred embodiment, the draw ratio in the range of about 4 to about 20 is extended. In a more preferred embodiment, the draw ratio on the scale of about 4 to about 15 is employed.

The draw ratio (DD), as used herein, is defined as the ratio of the cross-sectional area of the hole (A-i) to the cross-sectional area of the filament (A2). Said relationship is also frequently expressed as the winding speed ratio of the filament (V2) of the filament extrusion rate (Vi). In this way the stretch ratio, DD, can be expressed in terms of the following equation: In this way, according to the process of the present invention, thermotropic liquid crystalline polymer filaments having an essentially uniform molecular orientation can be made they show unusually superior mechanical properties. For example, by the proper practice of the method of the present invention it is possible to obtain a filament with a high number of deniers which has unattainable properties therein. More specifically, it has now been discovered that filaments having a denier on the scale of about 100 to about 1,000 denier per filament (dpf) can be easily made by the following method of the invention. In a preferred embodiment, filaments having a denier on the scale at about 150 to about 500 dpf can be easily made. In a more preferred embodiment, filaments having a denier on the scale of about 180 to about 300 dpf can be easily made. Denier, as used herein, is defined as a weight in grams of 9,000 meters of filament. The dpf as used herein is the denier of a single continuous filament. The conditions of temperature and pressure under which the liquid crystal polymer can be extruded are not important to the process of the present invention and can be readily determined by one skilled in the art. Typically, the thermotropic polymers are extruded at a temperature from about 280 ° C to about 480 ° C and at a pressure of approximately 70.3 kg / cm2 to approximately 3515 kg / cm'2 As described above, liquid crystal polymers have very rigid rod-like molecules. In the resting state, the polymer molecules are aligned in local regions, thus forming ordered or ordered domains. The existence of the domain texture in the microstructure of a liquid crystal polymer could be conformed by conventional polarized light techniques where a polarization microscope using cross-linked polarizers is used. The mechanical properties of the filaments produced according to the process of the present invention can be further improved by subjecting the articles to heat treatment after extrusion. The articles can be treated thermally in an inert atmosphere (for example, nitrogen, argon, helium). For example, the article may be placed at a temperature of about 10 ° C to about 30 ° C below the melting temperature of the liquid crystal polymer, at which temperature the filament remains a solid object. The periods of heat treatment commonly vary from a few minutes or a number of days, for example, from about 0.5 to 200 hours, or more. Preferably, the heat treatment is conducted for a period of from about 1 to about 48 hours (eg, from about 24 to about 30 hours). The heat treatment improves the properties of the article by increasing the molecular weight of the liquid crystalline polymer and increasing the degree of crystallinity. Thus, according to one of the preferred embodiments of the present invention, there is also provided a method for forming a heat-treated filament and a thermotropic liquid crystalline polymer having the following properties: (i) denier of at least about 50 deniers per filament; (ii) tenacity of at least about 20 g per denier; (iii) module of at least about 600 g per denier; (iv) elongation of at least about 3 percent. The process for forming said filament is comprised of the following steps: a) heating a thermotropic liquid crystalline polymer at a temperature from about 15 ° C to about 50 ° C above its melting transition to form a fluid stream of said polymer; b) extruding said polymer stream through a heated cylindrical spinner having at least one extrusion capillary to form a filament, wherein said capillary has an aspect ratio of length to diameter (L / D) on the scale of approximately 1 to about 10; c) winding said filament at a winding speed of at least about 200 meters per minute and stretching ratio of about 5 to about 40 to form a filament of essentially uniform molecular orientation in the cross section and having a denier on the scale of about 50 to about 1000 denier per filament; d) heat treating said filament at suitable temperature and pressure conditions for a sufficient period, optionally in the presence of an inert atmosphere, to form the heat treated filament. Any of the thermotropic polyesters or polyesteramides described above can be used in said preferred embodiment.

Furthermore, as described herein, the heat treatment can be carried out in stages at a final temperature of about 15 ° C below the melting transition of the thermotropic polymer. In another preferred embodiment of the present invention there is also provided a filament such as is spun from a thermotropic liquid crystalline polymer having the following properties: (a) denier of at least about 50 deniers per filament; (b) tenacity of at least about 8 grams per denier; (c) module of at least about 450 grams per denier; (d) elongation of at least about 2 percent. In a particularly preferred embodiment of the present invention, the filament denier as it is spun is on the scale of about 100 to about 1000 dpf. In a more particularly preferred embodiment of the invention, the filament denier as it is spun is on the scale of approximately 150 to approximately 500 dpf. In a more particularly preferred embodiment of the present invention, the filament denier as it is spun is on the scale of about 180 to about 300 dpf. In yet another preferred embodiment of the present invention, there is also provided a heat-treated filament of a thermotropic liquid crystalline polymer having the following properties: (a) denier of at least about 50 deniers per filament; (b) tenacity of at least about 20 grams per denier; (c) module of at least about 600 grams per denier; and (d) elongation of at least about 3%. In another aspect of the invention there is also provided a method for heat treatment of high denier filaments produced in accordance with the method of the present invention described above. In this aspect of the invention, the filaments wound in the coil are heat treated directly to obtain the heat-treated filaments, thereby offering significant cost savings. Thus, according to said aspect of the invention, the method is comprised of the following steps: (a) heating a thermotropic liquid crystalline polymer at a temperature of at least about 15 ° C above its melting transition to form a fluid stream of said thermotropic polymer; (b) passing said current through a heated extrusion chamber wherein said chamber is provided with a suitable cylindrical orifice to form the filament of said polymer, and wherein said cylindrical orifice has an aspect ratio of length to diameter (L / D) greater than about 1 and less than about 15; and (c) winding said filament in a coil at a low tension of at least about 5 grams and winding speed of at least about 200 meters per minute and draw ratio (DD) of at least about 4 to form the filament of essentially uniform molecular orientation in the cross section and having a denier of at least about 50 deniers per filament; Y (d) heat treating said filament directly in said coil at suitable temperature and pressure conditions for a sufficient period, optionally in the presence of an inert atmosphere, to form the heat treated filament. Thus, by practicing said aspect of the present invention, it is now possible to obtain a heat-treated filament having the following properties: (i) denier of at least about 50 deniers per filament; (ii) tenacity of at least about 20 grams per denier; (iii) module of at least about 600 grams per denier; and (iv) elongation of at least about 3 percent. Any of the polymers described above can be used in said aspect of the invention. The preferred thermotropic polymers are polyesters and polyesteramides as described above. Surprisingly, it has been found that applying low tension while winding the filament in the coil considerably improves the tensile properties of the filaments after heat treatment. For example, tensions of approximately 5 grams to 30 grams appear to be essential. It is preferred that said tensions of about 10 grams are applied to obtain the maximum benefit of the practice of the present invention. The present invention is further illustrated by the following examples, which are provided for purposes of illustration and not to limit the scope of the present invention.

EXAMPLES (GENERAL) The following abbreviations are used in the examples: HBA = 4-hydroxybenzoic acid HNA = 2,6-hydroxynaphthoic acid TA = terephthalic acid IA = soft acid NDA = 2,6-naphthalenedicarboxylic acid BP = 4,4'-Biphenol HQ = Hydroquinone AA = 1-Acetoxy-4-acetamidobenzene IV = Inherent viscosity dL / g = Deciliters per gram; a unit of measurement of IV% by weight = Percent by weight; Generally used to represent the concentration of a solution to measure IV- grams of polymer medium in 100 mL of a solvent mixture. MV = Viscosity of melted material DSC = Differential scanning calorimetry T = Tenacity M = Module E = Lengthening gpd = Grams per denier General analytical techniques used for polymer characterization: A variety of analytical techniques were used to characterize the polymer used and the filaments formed according to the present invention, which includes the following:] V: the solution viscosity of the polymer samples, IV, was measured at 25 ° C in a concentration of 0.1% by weight of solution in equal parts by volume of pentafluorophenol and hexafluoroisopropanol. MV: The MV of the polymer samples was measured using a model 2052 Kayeness melt rheometer equipped with a Hastalloy barrel and a connector tip. The radius of the die hole was 0.0381 cm and the length was 2.54 cm. For the purpose of determining the viscosity of molten material, a viscosity versus shear velocity plot was generated by measuring viscosities at shear rates of 56, 166, 944, 2388 and 8333 sec "1, and viscosities were interpolated to 100 and 1000 sec "1. DSC: the DSC of the polymer samples is carried out in a Perkin Elmer 7700 thermal analysis system. In all the tests, the samples sealed in aluminum trays were heated or cooled at a speed of 20 ° C / min under a nitrogen atmosphere. The DSC curves obtained from the second heating were taken for the analysis. Optical microscopy: Samples were prepared for microscopic analysis by thin sectioning using a glass knife microtome. The sections were examined by polarized optical microscopy to observe the morphological behavior at ambient temperatures.

EXAMPLE 1 Example 1 demonstrates the general increase in mechanical properties of a high denier filament as spun from a fully crystalline liquid aromatic polyester produced in accordance with the present invention, ie, filaments formed from a die having a of aspect (L / D) greater than 2 and a stretch ratio (DD) equal to or greater than 4. The filaments were formed of a fully crystalline liquid crystalline HBA / HNA polyester sold under the trade name "VECTRA TM A" ( Ticona LLC, Summit, NJ). Said polymer showed a melting temperature of 280 ° C and an inherent viscosity of 6.30 dL / g when measured in a concentration of 0.1% by weight in solution in equal parts per volume of pentaflurophenol and hexafluoroisopropanol at 25 ° C. A sample of the polymer was dried overnight at 130 ° C under vacuum. The polymer was melted in 2.54 cm of extruder diameter, and the extrudate was melted using a conventional polymer measurement pump to the spinner package where it was filtered through the 50-80 mesh material. The molten material was then extruded through a single-hole spinner and several aspect ratios (L / D) as listed in Table 1. The cross-flow extinction was applied to the emerging filament to provide cooling in an ambient environment. stable yarn. The extinction was placed 4 cm below the face of the spinner, and was 120 cm long by 15 cm wide. The extinction flow velocity in the upper part was 30 mpm (0.5 mpsec). The monofilament was coated with water or a spinning finish before going around a pulley system that controls the winding speed. It was usually taken on a Sahm reel winder. The mechanical properties of the monofilaments produced according to said example 1 were measured in accordance with ASTM D3822, and the results are listed in table 1. For purposes of comparison, the monofilaments were also extruded in the manner described above except that the DD ratios remained below 4. In some of these comparative tests, the spinners with low aspect ratios (L / D less than 2), as listed in table 1. The mechanical properties of said monofilaments were measured using the same procedures as described above and are also listed in table 1. The data provided in Table 1 indicate a considerable improvement in the properties of extruded monofilaments with spinners having aspect ratio (L / D) greater than one and DD ratio greater than 4 as compared to those extruded monofilaments with spinners having a ratio of aspect (L / D) less than 2 and DD ratios less than 4. This example demonstrates the effects b enriches achieved by extruding the liquid crystal polymer through spinners having L / D greater than 2 and a stretch ratio greater than 4 according to the process of the present invention. Note: in all the tables in the present, all the examples were tested in a length of 25 cm, 20% of deformation speed, 10 of filament breaking.

TABLE I EXAMPLE 2 The monofilaments produced according to example 1 were subjected to a heat treatment in stages in the following manner, the heat treatment of short lengths of the monofilament was carried out in rack under zero tension in a flow of dry nitrogen using a profile of programmed temperature. The temperature profiles programmed in each heat treatment of monofilaments are listed in table 2. The heat treated monofilament was tested in a length of 25.4 cm; 20% deformation speed and 10 filament break. After the heat treatment, the mechanical properties of the monofilaments were measured and listed in Table II. The measurements were made using the same tests as in Example 1. The data demonstrate the increase in properties, which is obtained by subjecting the monofilaments to the conditions of heat treatment in stages.

TABLE II OR? EXAMPLE 3 Examples 1 and 2 were repeated in Example 3, except that the high denier number filaments of the Vectra A polymer were formed. Table III summarizes the properties as they are spun and heat treated of the filaments.

TABLE III EXAMPLE 4 Examples 1 and 2 were repeated in Example 4, except that the thermotropic polyesteramide was used in Example 4. The polyesteramide A HNA / AA / TA that was used in Example 4 was sold under the trade name "VECTRA" ™ B "(Ticona LLC, Summit, NJ). Table IV-A summarizes the properties as they are spun and heat treated of the single filaments of high number of deniers formed from said polymer.

TABLE IV-A or Extruded filament samples of VECTRA ™ B were also treated with heat under optimal temperature and time conditions. The results of the above are listed in Table IV-B.

TABLE IV-B EXAMPLE 5 Examples 1 and 2 were repeated in Example 5, except that the thermotropic polyesteramide was used in Example 5. The polyesteramide used in the example comprises HBA, HNA, TA BP and AA units, and is sold under the trade name of "VECTRA ™ Ei" (Ticona LLC, Summit, NJ). Table V summarizes the properties as they are spun and heat treated of the single filaments of high number of deniers formed from said polymer.

TABLE V EXAMPLE 6 Examples 1 and 2 were repeated in example 6, except that the thermotropic polyesteramide was used in said example 6. The polyesteramide used in said example comprises units HBA, HNA, TA, BP and AA, and is sold under the name commercial "VECTRA ™ L" (Ticona LLC, Summit, NJ). Table VI summarizes the properties as they are spun and heat treated of the single filaments of high number of deniers formed from said polymer.

TABLE VI ül? EXAMPLE 7 In Example 7, the VECTRA ™ L filaments were prepared as in Example 6, except that it was made to a high number of deniers. The stretch was similar. Table VII summarizes the properties as they are spun and heat treated from the filament formed from said polymer.

TABLE VII Heat-treated properties for high-denier Vectra ™ L monofils.

EXAMPLE 8 Example 8 demonstrates that the filament heat treatment rolls it directly into the coil according to one of the preferred embodiments of the present invention. To develop the coil heat treatment capabilities, a heat treatment mechanism was constructed using a container equipped with rubber gaskets. A programmable forced air precision oven with copper tubing running along the internal walls was used to heat the coils after they were placed and sealed in the container. Nitrogen gas was introduced into the copper tube from 60 to 100 SCFH, making sure that the nitrogen gas penetrated the heat treatment package. The purge gas was heated as it passed through the furnace tube. The heated nitrogen passed into the vessel and flowed out from the center of the coil. Nitrogen was expelled from the vessel and out of the furnace, guaranteeing the removal of reaction products that could otherwise inhibit the formation of property. The heat treatment coils, 15.24 cm in diameter and approximately 33 cm in width, were constructed of perforated aluminum cylinders. The outer part of the cylinders was covered with fiberfrax, a porous ceramic mat, to accommodate the sinking of the monofilaments during the heat treatment. For safety reasons (particulate containment of glass), the fiberfrax was covered with polybenzimidazole (PBl) coatings. Based on empirical findings, a permanent layer of Vectran ™ yarn wound on top of the PBl coating offered better heat-treated properties. To improve packing formation (sleeves) for monofilament processing, aluminum tabs were also added at each end of the coils. For the coil preparation, the monofilaments as they are spun were screwed into the low tension heat treatment coils by the use of a Leesona coiler at 50 m / min. After the heat treatment, the fiber was rerolled on the final product spool. For the coil heat treatment, it was found that winding the fiber at low tension is essential to make the high voltage properties. By using the rewind tension, at low speed in the fiber lubricant (finished or water), monofilaments with surprising mechanical properties were obtained. The standard heat treatment process for monofilaments formed in accordance with the process of the present invention is shown below. The initial residence at 230 ° C was added to allow the softening point to increase and eliminate the fiber ribbon character. Heat treatment cycle: (1) Rapid increase to 230 ° C (2) Residence @ 230 ° C for two hours (3) Increase @ 15 ° C / hr to 270 ° C (4) Residence @ 270 ° C for 8 hours (5) Cooling to 100 ° C before opening the oven VECTRA A monofilaments were spun at 300 m / min and a suitable stretch to make 220 denier. For the improvement of the physical property, the filaments were heat treated in the coil to make continuous monofilaments treated with heat. The low tension during winding and rewinding is very important in the determination of the final properties. For this experiment, approximately 10 g of tension was considered critical during winding in the heat treatment coils in order to achieve optimum properties while making a clean coil that could be heat treated and unwind without any difficulty. Tensions less than 10 g produced coils in which the fiber separated from the coil and was difficult to unwind. The physical properties of the samples rewound with 10 g of tension @ 50 m / m are as follows: Tenacity = 25.89 g / d; elongation = 3.28% and modulus = 660.1 g / d.

EXAMPLE 9 Example 8 was repeated in Example 9, with the exception that the increased rewind tension of 20 g was used. The physical properties of the monofilament treated with heat are the following: Tenacity = 18.03 g / d; elongation = 2.20% and modulus = 650.8 g / d.

EXAMPLE 10 Example 8 was repeated in Example 10, with the exception that the two monofilament samples as spun were taken directly (during spinning at 300 m / min) in the heat treatment coils. Yarn line tensions were measured as 10 and 20 g with the physical properties shown below. Sample No. 1: Sample as spiked to Leesona @ m / m and 10 grams of tension: Tenacity = 20.3 g / d; elongation = 2.9%, modulus = 663 g / d Sample No 2: Sample as spun at Leesona @ 300 m / m and 20 grams of tension: Tenacity = 15.6 g / d; elongation = 2.2%; module = 652 g / d EXAMPLE 11 Comparison with a conventional procedure Examples 1 and 2 were repeated in Example 11, with the exception that the VECTRA ™ polymer monofilaments with high denier number were extruded using a water bath as an extinguishing system. The extruded monofilaments were approximately 200 deniers and were heat treated using the same system and conditions as Example 2. The results in the following Table VIII, which summarize the properties as spun and heat treated of the filaments, indicate clearly that monofilaments of extinction with water have inferior properties in relation to those shown in table II.

HIV TABLE Although the invention has been illustrated with the preceding examples, it is not intended to be limited thereby; on the contrary, the invention comprises the generic area as described above. Various modifications and modalities can be made without departing from the spirit and scope of the same.

Claims (47)

NOVELTY OF THE INVENTION CLAIMS

1. A process for forming a filament such as is spun from a thermotropic liquid crystalline polymer having the following properties: (i) denier of at least about 50 deniers per filament; (ii) tenacity of at least about 8 grams per denier; (iii) module of at least about 450 grams per denier; and (iv) elongation of at least about 2%; said method comprises the steps of: (a) heating a thermotropic liquid crystalline polymer at a temperature of at least about 15% above its transition of molten material to form a fluid stream of said thermotropic polymer; (b) passing said current through a heated extrusion chamber, characterized in that said chamber is arranged with a cylindrical hole suitable for forming the filament of said polymer, and wherein said cylindrical orifice has an aspect ratio of length to diameter ( L / D) greater than about 1 and less than about 15; and (c) winding said filament at a winding speed of at least about 200 meters per minute and draw ratio (DD) of at least about 4; and with the proviso that when L / D is between 0 to 2, the DD is at least 4 to form the filament of essentially uniform molecular orientation in its cross section and having a denier of at least about 50 lines per filament.

2. The process according to claim 1, characterized in that said thermotropic liquid crystalline polymer is selected from the group consisting of fully aromatic polyesters, aromatic-aliphatic polyesters, aromatic polyasomethines, aromatic polyesteramides, aromatic polyamides and aromatic polyester carbonates.

3. The process according to claim 1, characterized in that said thermotropic liquid crystalline polymer is a fully aromatic polyester.

4. The process according to claim 3, further characterized in that said polyester comprises a processable molten material of fully aromatic polyester capable of forming an anisotropic molten material phase at a temperature below about 350 ° C consisting essentially of recurring I and II where: I is is wherein said polyester comprises from about 10 to about 90 mole percent of portion I, and from about 10 to about 90 mole% of portion II.

5. The process according to claim 3, further characterized in that said polyester comprises a melt processable fully aromatic polyester capable of forming an anisotropic melt phase at a temperature below about 400 ° C consisting essentially of the portions recurrent i, II, III and VII where: I is is l l l is and Vi l is further characterized in that said polyester comprises from about 40 to about 70 mole percent of the portion I, from about 1 to about 20 mole percent of the portion II, and from about 14.5 to about 30 mole percent of each of the portions lll and Vil.

6. The process according to claim 1, characterized in that said thermotropic liquid crystalline polymer is a fully aromatic polyesteramide.

7. The process according to claim 6, further characterized in that said poliestamide comprises a melt processable fully aromatic polyesteramide capable of forming an anisotropic melt phase at a temperature below about 360 ° C consisting essentially of the recurrent II, I and VI where: is is V I is wherein said polyesteramide comprises from about 40 to about 70 mole percent of portion II from about 15 to about 30 mole percent of each of portions I and VI.

8. - The process according to claim 6, further characterized in that said polyesteramide comprises a melt-processable, fully aromatic polyesteramide capable of forming an anisotropic melt phase at a temperature below about 380 ° C consisting essentially of the recurring portions I , II, II VI and VII where: I is I I is l l l is I saw him V I is wherein said polyesteramide comprises from about 40 to about 70 mole percent of portion I, from about the approximately 20 mole percent of portion II, from about 14.5 to about 30 mole percent of portion III, from about 7 to about about 27.5 mole percent of the portion VII, and about 2.5 to about 7.5 mole of the portion VI.

9. The process according to claim 6, further characterized in that said polyesteramide comprises a melt processable fully aromatic poiestearam capable of forming an anisotropic melt phase at a temperature below about 350 ° C consisting essentially of the recurring I, II, III, IV, V and VI where: is is l l l is IV is You see V I is wherein said polyesteramide comprises from about 40 to about 70 mole percent of portion I, from about 10 to about 20 mole percent of portion II, from about 2.5 to about 20 mole percent of portion III, of about 0 to about 3 mole percent of the IV portion, from about 12.5 to about 27.5 mole% of the V portion and from about 2.5 to about 7.5 mole percent of the VI portion.

10. The method according to claim 1, further characterized in that said thermotropic liquid crystalline polymer is heated to a temperature of about 20 ° C to about 50 ° C above its melting transition.

11. The method according to claim 1, further characterized in that its aspect ratio (L / D) is from about 1 to about 10.

12. The method according to claim 1, further characterized in that said ratio of aspect (L / D) is from about 1 to 3.

13. The method according to claim 1, further characterized in that said draw ratio is from about 4 to about 20.

14. The method according to claim 1. 1, further characterized in that said stretch ratio is about 4 to about 15.

15. - The method according to claim 1, further characterized in that said filaments are a monofilament.

16. The method according to claim 15, further characterized in that the denier of said filament is from about 100 to about 1000 denier per filament.

17. The method according to claim 15, further characterized in that the denier of said filament is from about 150 to about 500 denier per filament.

18. The method according to claim 15, further characterized in that the denier of said filament is from about 180 to about 300 denier per filament.

19. The product produced by the process according to claim 1.

20. The product produced by the process according to claim 4.

21. The product produced by the process according to claim 5.

22. - The product produced by the process according to claim 7.

23. The product produced by the process according to claim 8.

24.- The product produced by the method according to claim 9.

25. - The product produced by the process according to claim 17.

26.- The product produced by the process according to claim 18.

27.- A process for forming a heat-treated filament and a thermotropic liquid crystalline polymer having the following properties: (i) denier of at least about 50 deniers per filament; (ii) tenacity of at least about 20 grams per denier; (iii) module of at least about 600 grams per denier; and (iv) elongation of about 3%; said method comprises the steps of: (a) heating the thermotropic liquid crystalline polymer at a temperature from about 15 ° C to about 50 ° C above its melting transition to form a fluid stream of said polymer; (b) extruding said polymer stream through a heated cylindrical spinner having at least one extrusion capillary to form a filament, characterized in that said capillary has an aspect ratio of length to diameter (L / D) in the scale of about 1 to about 10; (c) winding said filament at a winding speed of at least about 200 meters per minute and a stretch ratio of about 5 to about 40 to form a filament of essentially uniform molecular orientation in the cross section having a denier on the scale from about 50 to about 1000 denier per filament; and (d) heat treating said filament at suitable temperature and pressure conditions for a sufficient period, optionally in the presence of an inert atmosphere, to form the heat treated filament.

28. The process according to claim 27, further characterized in that said thermotropic liquid crystalline polymer is selected from the group consisting of: (i) a fully aromatic polyester processable by melting capable of forming an anisotropic melt phase at a temperature below about 350 ° C consisting essentially of the recurring portions I and II wherein: is I is wherein said polyester comprises from about 10 to about 90 mole percent of portion I; and from about 10 to about 90 mole percent of portion II; (ii) a fully aromatic polyester processable by melting capable of forming an anisotropic melt phase at a temperature below about 400 ° C which consists essentially of the recurring portions I, II, III and VII in which: is I I is l l l is I saw him O-C wherein said polyester comprises from about 40 to about 70 mole percent of portion I, from about 1 to about 20 mole percent of portion II, and from about 14.5 to about 30 mole percent of each of the portions III and VII; (iii) a fully aromatic, melt-processable polyesteramide capable of forming an anisotropic melt phase at a temperature below about 360 ° C consisting essentially of the recurring portions II, I and VI wherein: I is is I I I is wherein said polyesteramide comprises from about 40 to about 70 mole percent of portion II, from about 15 to about 30 mole percent of each of portions I and VI; (iv) a fully aromatic, melt-processable polyesteramide capable of forming an anisotropic melt phase at a temperature below about 380 ° C consisting essentially of the recurring portions I, II, III, VII and VI wherein: I is I I is is I saw him V I is wherein said polyesteramide comprises from about 40 to about 70 mole percent of portion I, from about 1 to about 20 mole percent of portion II, from about 14.5 to about 30 mole percent of portion III, of about 7. to about 27.5 mole percent of the portion VII, and from about 2.5 to about 7.5 mole percent of the portion VI; and (v) a fully aromatic, melt-processable polyesteramide capable of forming an anisotropic melt phase at a temperature below about 350 ° C consisting essentially of the recurring portions I, II, III; IV, V and VI where: is I is 15 IV e You see Y 1 is wherein said polyesteramide comprises from about 40 to about 70 mole percent of portion I, from about 10 to about 20 mole percent of portion II, from about 2.5 to about 20 percent of portion III, from about 0 to about 3 mole percent of the IV portion, from about 12.5 to about 27.5 mole percent of the V portion and from about 2.5 to about 7.5 mole percent of the VI portion.

29. The method according to claim 27 further characterized in that said aspect ratio (LD) is from about 1 to about 3.

The method according to claim 27, further characterized in that said heat treatment in the step (d) is carried out in stages at a final temperature of about 10 ° C to about 15 ° C below the melting transition of said thermotropic liquid crystalline polymer.

31. The method according to claim 27, further characterized in that the denier of said filament is from about 150 to about 500 denier per filament.

32. The method according to claim 27, further characterized in that the denier of said filament is from about 180 to about 300 denier per filament.

33. The product produced by the process according to claim 27.

34.- The product produced by the process according to claim 28.

35.- The product produced by the process according to claim 29.

36. - The product produced by the process according to claim 30.

37.- The product produced by the process according to claim 31.

38.- A filament such as is spun from a thermotropic liquid crystalline polymer having the following properties : (a) denier of at least about 50 deniers per filament; (b) tenacity of at least about 8 grams per denier; (c) module of approximately 450 grams per denier; and (d) elongation of at least about 2 percent.

39.- The filament according to claim 38, further characterized in that said thermotropic liquid crystalline polymer is selected from the group consisting of: (i) a fully aromatic polyester processable by melting capable of forming an anisotropic melt phase at a temperature below about 350 ° C consisting essentially of the recurring portions I and II wherein: I is is wherein said polyester comprises from about 10 to about 90 mole percent of portion I, and from about 10 to about 90 mole percent of portion II; (ii) a fully aromatic polyester processable by melting capable of forming an anisotropic melt phase at a temperature below about 400 ° C consisting essentially of the recurring portions I, II, III, and VII in which: I is I is I I is I saw him wherein said polyester comprises from about 40 to about 70 mole percent of portion I, from about 1 to about 20 mole percent of portion II, and from about 14.5 to about 30 mole percent in each of portions lll and Vil; (iii) a fully aromatic polyester amide processable by melting capable of forming an anisotropic melt phase at a temperature below about 360 ° C consisting essentially of the recurring portions II, I and VI where: I I is I is V I is wherein said polyesteramide comprises from about 40 to about 70 mole percent of portion I, from about 15 to about 30 mole percent of each of portions II and III; (V) a fully aromatic polyesteramide processable by melting capable of forming an anisotropic melt phase at a temperature below about 380 ° C consisting essentially of the recurring portions I, II, III, VII and VI wherein: is I I is l l l is I saw him V I is wherein said polyesteramide comprises from about 40 to about 70 mole percent of portion I, from about 1 about 20 mole percent of portion II, from about 14.5 about 30 mole percent of portion III, from about 7 to about 27.5 mole percent of the VII portion, and from about 2.5 to about 7.5 mole percent of the VI portion; and (v) a fully aromatic poisiesteramide processable by melting capable of forming an anisotropic melt phase at a temperature below about 350 ° C consisting essentially of the recurring portions I, II, III, IV, V and VI where : is II is lll is IV is 20 V is V wherein said polyesteramide comprises from about 40 to about 70 mole percent of portion I, from about 10 to about 20 mole percent of portion II, from about 2.5 about 20 mole percent of portion III, from about 0 to about about 3 mole percent of the IV portion, about 12.5 about 27.5 mole percent of the V portion and about 2.5 to about 7.5 mole of the VI portion.

40. The filament according to claim 38, further characterized in that the denier of said filament is from about 100 to about 1000 denier per filament.

41. The filament according to claim 38, further characterized in that the denier of said filament is from about 150 to about 500 denier per filament.

42. The filament according to claim 38, further characterized in that the denier of said filament is from about 180 to about 300 deniers per filament.

43. - A heat-treated filament of a thermotropic liquid crystalline polymer having the following properties: (a) denier of at least about 50 deniers per filament; (b) tenacity of at least about 20 grams per denier; (c) module of at least about 600 grams per denier; and (d) elongation of at least about 3 percent.

44. The filament according to claim 43, further characterized in that said thermotropic liquid crystalline polymer is selected from the group consisting of: (i) a fully aromatic polyester processable by melting capable of forming an anisotropic melt phase at a temperature below about 350 ° C consisting essentially of the recurring portions I and II wherein: is wherein said polyester comprises from about 10 to about 90 mole percent of portion I, and from about 10 to about 90 mole percent of portion II; (ii) a fully aromatic polyester processable by melting capable of forming an anisotropic melt phase at a temperature below about 400 ° C consisting essentially of the recurring portions I, II, III, and VII in which: I is I I is is I saw him wherein said polyester comprises from about 40 to about 70 mole percent of portion I, of about 1 about 20 mole percent of portion II, and about 14.5 to about 30 mole percent of each of portions III and VII; (Ii) a fully aromatic, melt-processable polyesteramide capable of forming an anisotropic melt phase at a temperature below about 360 ° C consisting essentially of the recurring portions II, I and VI where: I I is I is V I is wherein said polyesteramide comprises from about 40 to about 70 mole percent of portion II, from about 15 to about 30 mole percent of each of portions I and VI; (iv) a fully aromatic, melt-processable polyesteramide capable of forming an anisotropic melt phase at a temperature below about 380 ° C consisting essentially of the recurring portions I, II, III, VII and VI wherein: I is is is I saw him 10 V I is Wherein said polyesteramide comprises from about 40 to about 70 mole percent of portion I, from about 1 to about 20 mole percent of portion II, from about 14.5 to about 30 mole percent of the 20 portion III, and from about 7 to about 27.5 mole percent of the portion VII, and from about 2.5 to about 7.5 mole percent of portion VI; and (v) a fully aromatic, melt-processable polyesteramide capable of forming an anisotropic melt phase at a temperature below about 350 ° C consisting essentially of the recurring portions I, II, III, IV, V, # and VI where: I is I I is l l l is 15 IV e You see twenty. V wherein said polyesteramide comprises from about 40 to about 70% by mole of portion I, from about 10 to about 20% by mole of potion II, from about 2.5 to about 10 about 20 mole% of the portion III, from about 0 to about 3 mole% of the IV portion, from about 12.5 to about 27.5 mole% of the V portion and from about 2.5 to about 7.5 mole% of the portion VI.

45.- The filament according to claim 43, 15 further characterized in that the denier of said filament is from about 100 to about 1000 denier per filament.

46. The filament according to claim 43, further characterized in that the denier of said filament is from about 150 to about 500 denier per filament.

47. The filament according to claim 43, further characterized in that the denier of said filament is from about 180 to about 300 denier per filament.