JP2009521625A - Polyester yarn and production method - Google Patents

Abstract

A multifilament poly (trimethylene terephthalate) yarn is provided. The poly (trimethylene terephthalate) yarn has a crystal orientation function of at least 0.6 and an elongation at break of between 65% and 110%. Melt spinning poly (trimethylene terephthalate) into a multifilament yarn; cooling the yarn to a yarn temperature of less than 50 ° C .; and maintaining the yarn temperature at a yarn temperature of less than 50 ° C. while cooling the cooled yarn A method for forming a yarn is also disclosed that includes winding at a winding speed of at least about 3500 m / min.

Description

  The present invention relates to a polyester yarn. In particular, the present invention relates to partially oriented poly (trimethylene terephthalate) yarns and methods for making such yarns.

  Polyesters prepared by condensation polymerization of reaction products of diols and dicarboxylic acids can be melt extruded and spun into continuous multifilament yarns suitable for use in textiles and carpets. After spinning, the yarn can be wound onto a package to form a partially oriented yarn package or can be further processed immediately by heating and drawing the yarn to form a fully oriented yarn.

  Fully oriented polyester yarns can be used directly in methods for forming textiles and carpets. However, partially oriented polyester yarns may be stored and stored elsewhere prior to use in textiles or carpets for further processing, for example, by stretching and heat setting the yarn or by stretching-false twisting the yarn. Or can be shipped. Partially oriented yarns can be stretched, false twisted, and heat set in an integrated manner, eliminating the need for costly stretch-twisting operations, and are therefore Preferred yarn.

  A commonly used polyester yarn continuous multifilament poly (ethylene terephthalate) (PET) yarn can be made in multiple stages. A multi-filament PET partially oriented yarn is spun and wound on a yarn package in a first stage, unwound from the yarn package in a second stage, and pulled into a finished shape, and bulky stretched -Heat set or pulled on false twisted multifilament yarns-can be false twisted. Between these two stages, the multifilament PET partially oriented yarn package can be stored for a long time without any effect on the processing conditions and product quality of the second false twist stage and transported at high temperature Is possible.

  Poly (trimethylene terephthalate) (PTT) is a recently commercialized polyester with several desirable properties in textile and carpet applications, including high elasticity, soft texture, stain resistance and low modulus. Unlike PET yarns, multifilament PTT partially oriented yarns produced by conventional methods have presented a number of practical problems. One of the most serious problems is the instability of partially oriented yarn. This instability of the yarn can be observed in a variety of ways, including a deformed yarn package, a change in yarn properties as a function of time, and a change in yarn properties as a function of yarn depth on the yarn package. These problems have limited the usefulness of multifilament PTT partially oriented yarns.

  In contrast to PET multifilament partially oriented yarns, PTT multifilament partially oriented yarns have a significant tendency to shrink immediately after both spinning and winding, as well as hours or days after winding the yarn onto the yarn package. The shrinkage tendency of the PTT multifilament partially oriented yarn causes the yarn to shrink. The shrinkable yarn sometimes compresses the yarn package with the yarn wound so that the yarn package can no longer be removed from the chuck. Furthermore, during long-term storage or transport, the yarn package does not maintain the desired shape and forms a hard-edged bulge that causes severe unwinding problems and extreme increases in Worcester values. Only limiting the weight of the yarn package to less than 2 kg provides a solution to these problems not normally encountered when processing PET partially oriented yarns. However, yarn packages of less than 2 kg are less desirable than commonly used 10 kg to 20 kg yarn packages because they are more difficult to store and ship, and must be replaced very frequently for subsequent use. .

  Furthermore, it was observed that PTT multifilament partially oriented yarns were significantly exposed to aging related defects during storage compared to PET multifilament partially oriented yarns. Structural hardening of the PTT partially oriented yarn occurs over time, changing the properties of the yarn (eg, boil-off shrinkage and crystallinity) over time. Industrial use requires that multifilament yarns maintain this property over time so that subsequent processing of the yarn can be carried out continuously.

  Partially oriented PTT multifilament yarns produced by conventional polyester spinning methods tend to have a high degree of shrinkage due to the relatively high degree of axial orientation induced in the yarn at conventional polyester winding (spinning) speeds. The axial orientation induced in the amorphous phase of the multifilament PTT polyester partially oriented yarn is lost due to the aging of the yarn and the entropy driven unorganization of the amorphous phase, resulting in yarn shrinkage. For comparison, at normal commercial polyester spinning speeds from 3000 m / min to 3200 m / min, little axial orientation is induced in the PET yarn, the PET yarn does not shrink, and the PET partially oriented yarn package is shrink-stable. is there.

  One approach used to eliminate the shrinkage problem of multifilament partially oriented PTT yarns is the winding (spinning) used to spin the yarn as shown in US Pat. No. 6,287,688. ) To reduce the speed to 2600 m / min or less, for example from 1650 m / min to 2600 m / min or from 1000 m / min to 2000 m / min. Spinning at low winding speeds produces partially oriented PTT yarns with low axial orientation in the amorphous phase and low crystallinity. The resulting yarn is spun at conventional spinning speeds from 3000 m / min to 3200 m / min due to the relatively low degree of axial orientation of the amorphous phase that can be lost as a result of the entropy-driven reorientation of the yarn. Less shrinkage problems than multifilament PTT partially oriented yarns. However, this method produces a multifilament PTT partially oriented yarn that further undergoes significant shrinkage. This method is not commercially viable due to the slow yarn production rate at the required winding speed.

  Another approach used to eliminate the shrinkage problem of multifilament PTT partially oriented yarns is to use 50% yarn before winding the yarn onto the yarn package as shown in European Patent Application No. 1209262Al. It was to heat from 0 to 170 ° C. The heat treatment induces some crystallinity in the yarn and reduces the shrinkage of the yarn after winding. However, the resulting yarn lacks sufficient crystalline orientation to reduce the shrinkage so that it is totally negligible. The resulting partially oriented yarn can shrink to 40% in a boiling water shrinkage test.

SUMMARY OF THE INVENTION In one embodiment, the invention comprises a yarn comprising a multifilament poly (trimethylene terephthalate) yarn having a crystalline orientation function of at least 0.6 and an elongation at break of between 65% and 110%. About. In a preferred embodiment, the multifilament poly (trimethylene terephthalate) yarn has a boil-off shrinkage 30 days after the initial boil-off shrinkage of 10% or less relative to the initial boil-off shrinkage.

  In another embodiment, the present invention melt melt spins poly (trimethylene terephthalate); cools the melt spun poly (trimethylene terephthalate) to a multifilament yarn having a yarn temperature of less than 50 ° C; And winding a multifilament yarn having a yarn temperature of less than 50 ° C. at a winding speed of at least about 3500 m / min while maintaining the yarn at a yarn temperature of less than 50 ° C. It relates to a process for forming trimethylene terephthalate) yarns.

  In yet another embodiment, the present invention provides at most 22% initial boil-off contraction; less than 10% initial boil-off contraction 30 days after initial boil-off contraction; and 65% to 110% It relates to a yarn comprising a poly (trimethylene terephthalate) yarn having an elongation at break between.

DETAILED DESCRIPTION OF THE INVENTION The present invention provides partially oriented PTT multifilament yarns with little or no shrinkage and methods for making such yarns. The partially oriented PTT multifilament yarns of the present invention are particularly useful in the production of stable multifilament PTT partially oriented yarn packages that can be stored or shipped in a location other than where the yarn is spun for further processing. . In accordance with the present invention, by increasing the axial orientation of the multifilament PTT partially oriented yarn beyond a certain point, a highly oriented micro that stabilizes the yarn against shrinkage instead of increasing yarn shrinkage. A fibril yarn structure is obtained. Since shrinkage in multifilament PTT partially oriented yarn is due to rapidly induced axial orientation in yarn spinning and subsequent relaxation of induced orientation, increasing axial orientation in partially oriented PTT yarn resists shrinkage. Stabilizing the yarn was unexpected.

  In addition, heating the PTT multifilament yarn above the cold crystallization temperature of the PTT yarn and subsequently drawing the heated PTT multifilament yarn can produce crystallinity, orientation of the PTT yarn in the production of a fully oriented PTT multifilament yarn. Although it is known to significantly increase stability and stability, increasing the orientation in a multifilament PTT partially oriented yarn without inducing the full orientation in the yarn and heat fixing the induced orientation can lead to shrinkage. It was unexpected to resist the yarn against it. Since the orientation was expected to increase in the amorphous phase without significantly increasing the crystallinity of the yarn, the axis of the partially oriented PTT multifilament yarn without applying heat to the yarn above the cold crystallization temperature. It was particularly surprising that increasing the orientation stabilizes the yarn against shrinkage. As more yarns are sensitive to orientation relaxation, an increase in the orientation of the amorphous phase was expected to result in a low shrinkage stable partially oriented PTT multifilament yarn.

  In the present invention, the orientation of the PTT multifilament partially oriented yarn can be increased by spinning the yarn and winding the spun yarn without heat setting the yarn at a winding speed of at least 3500 m / min. . A winding speed of at least 3500 m / min creates sufficient spin line stress on the yarn during spinning, increasing the yarn orientation and preferably crystallization and most preferably the crystal orientation function. Unexpectedly, the axial orientation induced in the inventive PTT multifilament partially oriented yarn is relatively stable and the yarn causes little or no shrinkage.

  The PTT multifilament partially oriented yarns of the present invention have the further advantage that they are stronger than PTT multifilament partially oriented yarns wound at a speed lower than 3500 m / min as measured by the tenacity of the yarn. . The tenacity of the PTT multifilament partially oriented yarn of the present invention is preferably greater than 2.5 grams / denier, more preferably at least 2.6 grams / denier and most preferably at least 3.0 grams / denier.

Definitions As used herein, the term “birefringence” is a measure of the total orientation of a fiber or yarn. Here, total orientation is a measure of the combined orientation of the crystalline and amorphous phases of the fiber or yarn. The birefringence of the PTT multifilament partially oriented yarn is determined by measuring the amount of optical deceleration Γ caused by fiber anisotropy in the PTT fiber under an optical microscope with crossed polarizers using a rotating quartz compensator. When measuring Γ, the fiber sample is rotated 45 ° to the left or right of the extinction position to increase the phase contrast. Three sets of measurements are obtained and the average value is shown. Birefringence is calculated from the amount of optical deceleration and the fiber diameter t using the following formula: birefringence = Γ / t.

As used herein, “boil-off shrinkage” is a measure of the degree of shrinkage of a yarn. Boil-off shrinkage can be measured according to the following procedure. A 4500 denier yarn skein is made using a standard denier creel with a circumference of 1 m. Measure the yarn denier and calculate the number of turns required to wind the yarn around the creel to obtain a 4500 denier yarn skein by the formula: Number of wraps required = (4500 / [yarn denier measurement]) And a 4500 denier yarn skein is made by winding the yarn around the creel by the calculated number of wraps. The initial skein length (L _i ) is measured by applying a 500 g load on the skein and measuring the length of the skein. Next, skeins are stacked and covered with gauze to prevent entanglement. The skein is then placed in a boiling water bath for 30 minutes, then removed from the bath and allowed to cool for 15 minutes. Next, the length of the skein after shrinking (L _s ) is measured by placing the cloth on the skein and drying, applying a load of 500 g on the skein, and measuring the length of the skein. Boil-off shrinkage (%) is

により求められる。

It is calculated by.

  As used herein, “crystalline / amorphous lamellar period” is defined as the average length of crystalline and amorphous lamellae arranged vertically in a microfibril structure as measured by small angle X-ray scattering. The

  As used herein, the term “crystalline orientation” is defined as the degree of axial orientation induced in a yarn or filament by the crystalline phase of the yarn or filament. Crystalline orientation includes the degree of orientation in the yarn or filament of the crystalline portion of the yarn or filament. Crystalline orientation can induce the crystalline phase of the yarn or filament in the amorphous phase of the yarn or filament, for example by keeping the amorphous phase in the oriented state in the yarn or filament by entanglement, bonding or clamping Includes the degree of orientation. Crystalline orientation is a measure of the degree of orientation within a yarn or filament that is not sensitive to significant relaxation. In comparison, birefringence is sensitive to significant relaxation and is a measure of the crystallinity of the yarn or filament and the total orientation of the amorphous phase, including orientation in the amorphous phase that is not retained in the yarn by the crystalline phase. It is.

As used herein, the term “crystal orientation function” is defined as a measure of the crystalline orientation of a yarn or filament. Crystalline orientation function f _c, for the yarn or filament by using a wide angle X-ray diffractometer (010) is determined from the azimuth scan at 2θ angles of 15.66 ° of reflection intensity I (alpha). The azimuth angle α to be scanned is 0 to 90 °. Then, the crystal orientation function f _c may be calculated using the following equation.

The sine mean square angle <sin ² α> of the yarn / filament (010) reflection is performed along with the stretching direction.

(010) Reflection orientation f ₀₁₀ is

により与えられる。

Given by.

  Since (010) is the equator reflection,

によりヤーン／フィラメントファイバー軸の配向の結晶配向関数に関連付けられる。

Is related to the crystal orientation function of the orientation of the yarn / filament fiber axis.

As used herein, the term “crystallinity” is a measure of the crystallinity (or fraction%) of a yarn. Crystallinity can be determined using a differential scanning calorimeter (DSC), such as a Perkin-Elmer DSC-7. A sample of yarn is placed in an aluminum pan and heated from 30 ° C. to 270 ° C. at a rate of 10 ° C. per minute. Heat of fusion (ΔH) at about 228 ° C. when the PTT polymer is a homopolymer without added polymer and at about 215 ° C. to about 228 ° C. when the PTT polymer contains a comonomer or other polymer. Is measured by DSC. If the DSC scan shows some low-temperature crystallization or pre-melt exotherm as shown by absorption at about 70 ° C. to about 150 ° C., the heat of fusion is corrected by subtracting the measured exotherm from the heat of fusion ( By obtaining ΔH _corrected ), the measured heat of fusion can be _corrected , and if a low temperature exotherm is not indicated by the DSC scan, ΔH _corrected is about 215 ° C. to 228 ° C. for purposes of the following equation: Equal to the measured ΔH. The crystallinity (%) of the sample is

により計算され得る。式中、ΔＨ_ｆは１００％結晶性ＰＴＴの溶融熱であり、３５ｃａｌ／ｇと定義される。

Can be calculated by: Where ΔH _f is the heat of fusion of 100% crystalline PTT and is defined as 35 cal / g.

Alternatively, the heat of fusion ΔH may be used to heat the yarn to a temperature above its melting point, preferably 245 ° C. to 255 ° C., until the yarn is completely melted, and to cool the molten yarn to a temperature of about 160 ° C. to 180 ° C. Can then be measured by reheating the cooled molten yarn to a temperature of 270 ° C. at a rate of 10 ° C. per minute. Upon reheating from the melting point, the heat of fusion (ΔH) is about 228 ° C. if the PTT polymer is a homopolymer without further polymer, or if the PTT polymer contains a comonomer or other polymer, Measured by DSC at about 215 ° C to about 228 ° C. Heating the yarn first above the melting point before measuring the heat of fusion heat eliminates the crystallinity that causes the low temperature heat generation, so no correction is required for the low temperature cold crystallization heat generation. Percent crystallinity can be determined by the above equation where ΔH _corrected is equal to ΔH.

The crystallinity of the yarn is also related to the density of the yarn. In particular, the formula: percent crystallinity _{= D c / D m × [} (D m -D a) / (D c -D a)] × 100%, determined from the percent measured density of the yarn is crystalline be able to. Where D _m is the measured density, D _c is the density of 100% crystalline yarn, and D _a is the density of 100% amorphous yarn (0% crystalline). For PTT yarn, D _c = 1.442 and D _a = 1.295. The measured density D _m can be measured at a temperature of 23 ± 0.1 ° C. in a density / gradient tube. Two concentrations of sodium bromide can be used to determine the expected density range of the material under test.

  As used herein, the term “elongation at break” refers to a yarn break from a relaxed state caused by a tensile force, measured as a percentage increase in yarn length over the length of the relaxed yarn at break at full elongation. Is defined as the increase in length in the yarn until. Elongation at break can be measured by ASTM (American Society for Testing and Materials) method D2101 with a Statimat tensile tester. The average of 10 tests is shown.

  As used herein, the term “heat of fusion” of a PTT yarn is defined as the amount of heat required to convert a unit weight of PTT yarn from the solid state to the liquid state without increasing the temperature at the melting point of the PTT. . The heat of fusion of the PTT yarn can be measured using a differential scanning calorimeter (DSC) as described above.

  As used herein, the term “initial”, when used to describe a yarn or filament property or measurement, is defined as a yarn or filament property or measurement measured within 24 hours of the yarn being spun. Is done. For example, the initial boil-off shrinkage of the yarn is the yarn boil-off shrinkage measured within 24 hours of the yarn being spun.

  As used herein, the term “melt spinning” of a polymer is defined as the process of melting a polymer by heating the polymer above its melting point and extruding the molten polymer from one or more spinnerets.

  As used herein, the term “partially oriented yarn” has a moderate to high extensibility, preferably greater than 65%, indicating a lower crystallinity than a fully oriented yarn, usually 45 to less than 50%. Is defined as a yarn of polymer filaments having an elongation at break of. The partially oriented yarn is usually a yarn that has not been heated above the glass transition temperature or the cold crystallization temperature and has been stretched while being heated.

  A “partially oriented PTT yarn” or “PTT partially oriented yarn” is defined herein as a yarn formed from a PTT polymer having an elongation at break of 65% or greater as measured by ASTM method D2101.

  “PET” as used herein means poly (ethylene terephthalate).

  “PTT” as used herein means poly (trimethylene terephthalate).

  "PTT polymer" is defined herein as a polyester polymer containing at least 85 wt% PTT and up to 15 wt% comonomer; other polymers include PET, polybutylene terephthalate, and nylon; Products such as catalysts, stabilizers, antistatic agents, antioxidants, flame retardants, colorants, colorant absorption modifiers, light stabilizers, organic phosphites, whitening agents and matting agents; or mixtures thereof .

  A “PTT yarn” is defined herein as a polyester yarn containing at least 85% by weight PTT and up to 15% by weight comonomer or other polymer.

  As used herein, the terms “shrinkage stability” and “little or no shrinkage” with reference to the yarn or filament have an initial boil-off shrinkage of the yarn or filament of at most 22%, and the initial Defined to mean having a boil-off shrinkage of 30 days after the initial boil-off shrinkage of 10% or less relative to the boil-off shrinkage.

  As used herein, the term “winding speed” is defined as the speed of the winding mechanism that winds the yarn from the spinneret. The winding mechanism is preferably a roll or a set of rolls, most preferably a godet roll. However, this can be any spinning winding mechanism conventional in the field of yarn spinning.

  As used herein, the term “tenacity” is a measure of the strength of a yarn. Tenacity can be measured using a Statimat yarn tensile tester according to ASTM method D2101. The average of 10 tests is shown.

Process for Producing Shrink-Stable Partially Oriented PTT Yarns PTT multifilament partially oriented yarns that cause little or no shrinkage according to the present invention are obtained by melt spinning poly (trimethylene terephthalate), cooling melt spun PTT, and 50 ° C. It can be produced by making a multifilament yarn having a yarn temperature of less than and winding the multifilament yarn at a winding speed of at least about 3500 m / min while maintaining the yarn at a yarn temperature of less than 50 ° C. Winding the spun yarn at a speed of at least 3500 m / min creates sufficient spin line stress on the yarn during spinning, induces sufficient orientation and crystallinity in the yarn, and stabilizes the yarn against shrinkage Turn into.

  In order to produce the PTT multifilament partially oriented yarn of the present invention, a PTT polymer is provided for melt extrusion. PTT polymers are known in the art along with methods for making PTT polymers. A PTT polymer can be obtained by polycondensation reaction of terephthalic acid with an equimolar amount of 1,3-propanediol. The PTT polymer can be a homopolymer or can be a PTT copolymer containing a small amount of non-PTT comonomer. Suitable examples of PTT copolymers include those containing at most 15 mol%, preferably at most 10 mol%, and more preferably at most 5 mol% comonomer in addition to PTT repeating monomer units. . Such comonomers include, but are not limited to, ethylene glycol, 1,4-cyclohexanedimethanol, oxalic acid, succinic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid, 5-sodium sulfoisophthalic acid, isophthalic acid and / or Or it may contain adipic acid. However, in the present invention, the use of PTT homopolymer is preferred.

  The PTT polymer can also be blended with small amounts of other polymers such that the other polymers do not exceed 15%, preferably 10%, more preferably 5% by weight of the PTT polymer blend. The PTT polymer can be blended with other polymers by melting the PTT polymer and the other polymer together or by melting the PTT polymer and the other polymer separately and coalescing the molten polymer. Other polymers useful for blending with the PTT polymer in the method of the present invention include PET, poly (butylene terephthalate) and nylon.

  The PTT polymer may contain small amounts of further additives as an admixture. Such additives include catalysts, stabilizers, antistatic agents, antioxidants, flame retardants, colorants, colorant absorption modifiers, light stabilizers, organic phosphites, whitening agents and matting agents. Preferably, the PTT polymer contains 0 to 5% by weight of such additives based on the total weight of the PTT polymer.

  PTT polymers having an intrinsic viscosity of 0.7 dl / g to 1.3 dl / g are particularly useful in the method of the present invention. Most preferably, PTT polymers having an intrinsic viscosity of 0.85 dl / g to 1.1 dl / g are used in the process of the present invention.

  Referring to FIG. 1, a PTT polymer chip or pellet can be melted and extruded from a spinneret 1 to form a filament 2 (ie, melt-spun PTT polymer to form filament 2). Preferably, the PTT polymer chips or pellets are dried to a water content of at most 30 ppm, more preferably at most 15 ppm prior to extrusion to minimize degradation of the PTT polymer. The PTT polymer can be melted and extruded in a conventional uniaxial or biaxial thermoplastic extruder having a spinneret 1 attached to the outlet of the extruder.

  The PTT polymer can be heated in the extruder or prior to entering the extruder at or above the temperature at which the PTT polymer melts but below the temperature at which the PTT polymer causes significant degradation. The melting temperature of the homopolymer PTT is from about 225 ° C. to about 240 ° C., and the melting temperature of the PTT polymer containing the comonomer or copolymer can be in the range of 200 ° C. to 250 ° C. Preferably, the PTT polymer can be heated to a temperature of at least 245 ° C. to melt the polymer. Also preferably, the PTT polymer can be heated to a temperature below that at which the PTT polymer causes significant degradation. Preferably, the PTT polymer can be heated to a temperature of at most 280 ° C. Most preferably, the PTT polymer can be heated to a temperature of 250 ° C to 260 ° C. The extruder can be a multi-stage extruder where the PTT polymer is heated at different temperatures within the stage of the extruder. For example, in an extruder, the PTT polymer is heated from 245 ° C. to 250 ° C. in the first stage, from 250 ° C. to 255 ° C. in the second stage, and from 255 ° C. to 260 ° C. in the third and fourth stages. It can be a four-stage extruder.

  The molten PTT polymer is extruded from the spinneret 1 to form a plurality of melt-spun continuous filaments 2 and exits the spinneret 1 from a number of die holes in the die front surface 4 of the spinneret. Preferably, the die hole in the die front face 4 of the spinneret has a round cross-section, but the die hole has other shapes such as trefoil, triangle, and other non-round cross-sections commonly used in the partially oriented yarn industry. Can have. The die holes can have a size selected to provide the desired properties of the yarn. Preferably, the die hole has a diameter of 0.1 to 0.5 mm, more preferably 0.2 to 0.4 mm. Preferably, the spinneret 1 has sufficient die holes to provide a sufficient number of filaments 2 to be formed into a yarn of the desired characteristics. Preferably, for example, the spinneret 1 can have 10 to 100 die holes through which molten PTT can be extruded into the filaments 2. Multiple spinnerets (not shown) can be attached to the extruder to allow multiple yarns to be spun simultaneously from the molten PTT polymer.

  The melt spun PTT polymer is cooled to form a multifilament yarn having a yarn temperature of less than 50 ° C. Preferably, the melt spun filaments 2 are coalesced to form a multifilament yarn 7 while being cooled by quench air.

  In a preferred embodiment, the filament 2 first exits the spinneret 1 and enters a delayed quench zone 3 which is located between the spinneret die front 4 and quench air 5. The delayed quench zone 3 provides a zone where the molten filaments equilibrate and receive irregularities, such as non-uniform thickness or non-uniform stretch, before receiving the quenching air for cooling. The delayed quench zone 3 may have a length of 0.1 to 30 centimeters, preferably 0.5 to 20 centimeters. Preferably, the delayed quench zone 3 is heated to 265 ° C. In an alternative embodiment, there is no delayed quench zone 3.

  The filament 2 can then be cooled and solidified into a multifilament yarn. After passing through the delay quench zone 3 (if a delay quench zone exists), the filament 2 exposes the filament 2 to the quench air 5 in a quench air zone that may have a length of 0.1 to 2 meters. Can be cooled. Preferably, the quench air 5 has a cold temperature relative to the temperature of the filament and exits the delayed quench zone 3 or the spinneret 1. Most preferably, the quench air temperature is between 10 ° C and 30 ° C. If the delayed quench zone 3 is not used, preferably the quench air temperature is at the lower end of the above temperature range, preferably 10 ° C to 20 ° C. Preferably, the quench air 5 is blown across the filament 2 or possibly along the length of the filament 2. Preferably, the quenching air 5 is blown at a speed of 0.1 to 0.8 m / sec, more preferably 0.3 to 0.7 m / sec. Most preferably, the quench air 5 has a humidity of 50% to 98%, more preferably 65 to 85%.

  In one embodiment, inter alia, the filament 2 passes through a cylinder (not shown) surrounding the filament 2 that defines a quench air box or an air quench zone that exposes the filament 2 to the quench air 5. The quench air 5 is directed inward from the quench air box or the inner surface of the cylinder to cool the filament 2.

  The filament 2 can be focused on the multifilament yarn 7 while being cooled by the quench air 5. The resulting multifilament yarn 7 can also be cooled by the quench air 5. In another embodiment, the melt spun filaments are combined before being cooled with quench air to form a multifilament yarn, where the resulting multifilament yarn can be cooled with quench air. In yet another embodiment, the filaments can be combined after processing the filaments with quench air to form a multifilament yarn. However, in each embodiment, the resulting multifilament PTT yarn has a yarn temperature of less than 50 ° C. prior to winding by the winding mechanism.

  The multifilament PTT yarn 7 can be passed through the spin finish applicator 6 as an oiling roll to apply the finish onto the yarn 7. Preferably, the finish is an oil containing a fatty acid ester and / or mineral oil or polyether.

  Next, the multifilament PTT yarn 7 is at least 3500 meters per minute (m / min) or at least 3600 m / min or at least 3700 m / min or at least 3800 m / min or at least 3900 m / min by a winding mechanism during spinning. Taken up at a winding speed of minutes or more preferably at least 4000 m / min to impart a spin line stress in the yarn 7 and induce a significant degree of axial orientation in the yarn 7. Preferably, the yarn 7 has a winding speed of at most 5400 m / min or at most 5300 m / min or at most 5200 m / min or at most 5100 m / min or at most 5000 m / min. Taken over. Preferably, the yarn 7 is taken up at a winding speed of 3500 m / min to 5400 m / min, more preferably 3800 m / min to 5000 m / min, most preferably 4000 m / min to 4500 m / min.

  The multifilament PTT yarn is taken up by a winding mechanism operated at a desired winding speed. The winding mechanism can be any conventional mechanism for winding multifilament yarns. Preferably, the multifilament PTT yarn 7 is taken up by a godet roll 8 that rotates at a desired winding speed.

  The multifilament PTT yarn 7 is taken up at the desired winding speed, but the winding speed should be at least 3500 m / min while maintaining the yarn at a yarn temperature below 50 ° C. When the godet roll 8 is used to wind up the yarn, the godet roll 8 is preferably not heated or cooled below the ambient temperature, but if not heated to a temperature below the cold crystallization temperature of the yarn 7. Having a temperature to heat the yarn. Most preferably, the godet roll 8 is not heated, but if heated, has a temperature that heats the yarn to a yarn temperature of less than 50 ° C.

  If desired, other godet roll sets can be placed between the winding mechanism and the winder to smooth the take-up and winding process. The other godet roll sets must not be operated at a speed effective to impart substantial stretching to the yarn. Preferably, the other godet roll set is a freely rotating roll, or is equal to or slightly slower than the winding speed, preferably 0% to 5% slower than the winding speed, more preferably winding. It must be driven at a speed 0% to 1% slower than the speed.

  The resulting partially oriented PTT multifilament yarn 7 is then preferably 0% to 5% slower than the winding speed of the winding mechanism (eg godet roll 8), more preferably 0% to 1 below the winding speed. It can be wound on the yarn package 9 with a% slower winding speed. By winding the yarn 7 at a speed slightly lower than the winding speed, the stress on the yarn 7 when winding on the yarn package 9 can be reduced.

  The yarn package can be any conventional yarn package, such as a cheese-shaped yarn package 11, for example as shown in FIG. Importantly, the PTT multifilament partially oriented yarn can be wound onto a yarn package sized such that the weight of yarn 7 and yarn package 11 is at least 5 kg, 10 kg or 15 kg. Preferably, the resulting yarn package 11 is stable against deformation induced by yarn shrinkage since the yarn causes little or no shrinkage. For comparison purposes, FIG. 3 shows a yarn package 15 having a yarn 13 (not of the present invention) thereon, where the yarn 13 has a deformation induced in the yarn package 15.

  The yarn package 11 can subsequently be used in further processing, such as stretching or tension false twisting operations. The PTT multifilament partially oriented yarn 7 wound on the yarn package 11 can be unwound from the yarn package 11 and subjected to stretching and false twisting operations during unwinding. The yarn package 11 may be stored for a period of at least 1 day, at least 1 week or at least 30 days prior to use in further processing such as drawing and false twisting. Preferably, the stored yarn package 11 is stable against deformation induced by yarn shrinkage during storage and subsequent use. Alternatively, the yarn package 11 can be transported from a location where the yarn 7 is wound onto the yarn package 11 for use in further processing at a different location. Preferably, the transported yarn package 11 is stable against deformation induced by yarn shrinkage during transport and subsequent use.

  The high winding speed of at least 3500 m / min spinning the PTT partially oriented yarn of the present invention also results in sufficient spin line stress in the yarn during spinning, at least 0.6, more preferably at least 0.7. More preferably, a crystal orientation function of at least 0.8, most preferably at least 0.9, is induced in the yarn. As shown in FIG. 4, there are three distinct regions of crystal orientation function in the PTT partially oriented yarn as a function of winding speed. At low winding speeds from 2900 to 2500 m / min or less, PTT partially oriented yarns have a low crystal orientation function that reflects that almost no stable orientation was induced in the yarn due to the spin line stress. At conventional polyester winding speeds from 3000 m / min to 3200 m / min, as well as 3500 m / min, the PTT partially oriented yarn increases rapidly reflecting an increase in the stable orientation induced in the yarn by spin line stress. It has a crystallographic orientation function, but has a stable orientation that is insufficient for the yarn to be shrink-stable. At the high winding speed of at least 3500 m / min provided in the present invention, the PTT partially oriented yarn has a high crystal orientation function. Although not wishing to be bound by theory, partially oriented yarns spun at a take-up speed of at least 3500 m / min are spun with sufficient crystalline orientation that the yarn is relatively stable against relaxation. It is believed that at least a portion is shrink-stable without being heat set because it was induced in the yarn by linear stress.

A high winding speed of at least 3500 m / min for spinning the PTT partially oriented yarn of the present invention results in sufficient spin line stress in the yarn during spinning, at least 35% (density of at least 1.344 g / cm ³ ). More preferably at least 36% (density of at least 1.345 g / cm ³ ), more preferably at least 37% (density of at least 1.347 g / cm ³ ), more preferably at least 38% (at least 1.348 g). of / density of cm ^3), more preferably induces at least 39% (density of at least 1.350 g / cm ^3), crystalline and most preferably at least 40% (density of at least 1.351g / cm ³⁾ . As shown in FIG. 5, the crystallinity of the PTT partially oriented yarn increases at a high winding speed, and at the high winding speed of at least 3500 m / min provided in the present invention, the PTT partially oriented yarn has a low winding. Compared to other PTT partially oriented yarns spun at speeds, such as those used in conventional polyester spinning from 3000 m / min to 3200 m / min, especially at speeds as low as 2600 m / min. Has a relatively high degree of crystallinity. Although not wishing to be bound by theory, these yarns spun at a take-up speed of at least 3500 m / min are spun with sufficient crystalline orientation that the yarn is relatively stable against relaxation. It is believed that at least a portion is shrink-stable without being heat set because it was induced in the yarn by linear stress.

  The high winding speed of at least 3500 m / min spinning the PTT partially oriented yarn of the present invention results in sufficient spinning line stress in the yarn during spinning, at most 22%, more preferably at most 20% It also induces an initial boil-off shrinkage of more preferably at most 19%, more preferably at most 18%, most preferably at most 17%. Without wishing to be bound by theory, it is believed that the decrease in initial boil-off shrinkage correlates with an increase in crystalline orientation, as shown by the increase in crystal orientation function in FIG.

  A high winding speed of at least 3500 m / min for spinning the PTT partially oriented yarn of the present invention results in sufficient spinning line stress in the yarn during spinning, less than 10% relative to the initial boil-off shrinkage, more preferably the initial It also induces a boil-off shrinkage of 30% or less after the initial boil-off shrinkage of 8% or less relative to the boil-off shrinkage, more preferably 6% or less relative to the initial boil-off shrinkage, and most preferably 5% or less relative to the initial boil-off shrinkage. For example, if the initial boil-off shrinkage of the PTT partially oriented yarn produced by the method of the present invention is 17%, the boil-off shrinkage after 30 days is preferably 7% to 17%, more preferably 9% to 17%. More preferably, it is 11% to 17%, and most preferably 12% to 17%. As shown in FIG. 6, as the winding speed for spinning the yarn approaches 3500 m / min, the 30-day boil-off shrinkage of the PTT partially oriented yarn is significantly reduced and is at a low level at a winding speed of 3500 m / min and higher. Maintained.

  The high winding speed of at least 3500 m / min spinning the PTT partially oriented yarn of the present invention causes sufficient spin line stress on the yarn during spinning to induce an initial birefringence of at least 0.05 in the yarn. More preferably, a high winding speed of at least 3500 m / min spinning the PTT yarn induces an initial birefringence of 0.06 to 0.085. As shown in FIG. 7, the birefringence of the PTT partially oriented yarn increases as the winding speed for spinning the yarn increases.

  Preferably, a high winding speed of spinning at least 3500 m / min spinning the PTT yarn results in sufficient spinning line stress in the yarn during spinning, in contrast to about 50 small diagonal X-ray scattering of PET fibers. Microfibril structure exhibiting double-point meridian small-angle X-ray scattering with crystalline / amorphous lamellar periodicity from about 100 Angstroms to the lamellar periodic PTT of the present invention instead of being stacked diagonally as in PET fiber The yarns are arranged in layers along the fiber direction); at least 2.5 grams / denier, more preferably at least 2.6 grams / denier, more preferably at least 2.7 grams / denier, most preferably Tenacity of at least 3.0 grams / denier; more preferably between 70% and 110% Elongation at break from 75% to 105%; and at least 12 calories / gram (50.2 J / g), more preferably at least 13 cal / g (54.4 J / g), more preferably at least 14 cal / g ( A heat of fusion of 58.6 J / g), most preferably at least 15 cal / g (62.8 J / g) is also induced in the yarn.

PTT Partially Oriented Yarn Composition The present invention also relates to a multifilament PTT partially oriented yarn that causes little or no shrinkage. The multifilament PTT partially oriented yarn of the present invention may have a crystal orientation function of at least 0.6, more preferably at least 0.7, more preferably at least 0.8, and most preferably at least 0.9. . The multifilament PTT partially oriented yarn of the present invention is at least 35% (density of at least 1.344 g / cm ³ ), more preferably at least 36% (density of at least 1.345 g / cm ³ ), more preferably at least 37% (density of at least 1.347 g / cm ³ ), more preferably at least 38% (density of at least 1.348 g / cm ³ ), more preferably at least 39% (density of at least 1.350 g / cm ³ ) At least 12 cal / g (50.2 J / g), more preferably at least 13 cal / g (54. 5), corresponding to a crystallinity of at least 40% (density of at least 1.351 g / cm ³ ). 4 J / g), more preferably at least 14 cal / g (58.6 J / g), Also preferably may have a heat of fusion of at least 15cal / g (62.8J / g). The multifilament PTT partially oriented yarn of the present invention is at most 22%, more preferably at most 20%, more preferably at most 19%, more preferably at most 18%, most preferably May have an initial boil-off shrinkage of at most 17%. The multifilament PTT partially oriented yarn of the present invention has an initial boil-off shrinkage of 10% or less, more preferably an initial boil-off shrinkage of 8% or less, more preferably an initial boil-off shrinkage of 6% or less. And most preferably it may have a boil-off shrinkage of 30% after the initial boil-off shrinkage of 5% or less relative to the initial boil-off shrinkage. The multifilament PTT partially oriented yarn of the present invention may have an initial birefringence of at least 0.05, most preferably 0.06 to 0.085. The multifilament PTT partially oriented yarn of the present invention has a double-point meridian small angle X-ray scattering with a crystalline / amorphous phase lamellar periodicity of about 50 to about 100 Angstroms, at least 2.5 grams / denier, more preferably at least 2.6 grams / denier, more preferably at least 2.7 grams / denier, most preferably at least 3.0 grams / denier tenacity; and 65% or more, 70% or more, at least 75%, less than 110% Microfibrillar structures exhibiting an elongation at break of at most 105%, at most 100%, between 65% and 110%, 70% to 105%, or 75% to 100% Can have.

  As shown in FIG. 2, the multifilament PTT partially oriented yarn 7 of the present invention is preferably wound into a yarn package, for example a cheese-shaped yarn package 11. The yarn package 11 can be any conventional yarn package, preferably a yarn package sized and dimensioned such that the weight of the yarn and yarn package is at least 5 kg, 10 kg, or 15 kg.

  The yarn package 11 wound with the PTT partially oriented yarn 7 of the present invention is more stable than conventional PTT partially oriented yarn against deformation induced by yarn shrinkage. Preferably, shrinkage and deformation of the yarn package 11 does not occur. However, if shrinkage occurs, this does not occur to the extent that the yarn package 11 is deformed to form a hard-edged bulge, and the yarn package is shown in FIG. 3 (the yarn deformed by shrinkage of the unstable yarn 13). The chuck cannot be removed as shown schematically in a non-conventionally shrinkable PTT partially oriented yarn 13 wound on a package 15 which is not of the present invention.

  Partially oriented PTT multifilament yarns were prepared by the method of the present invention at winding speeds of 3500 m / min, 4000 m / min and 4500 m / min and measured for crystallinity, birefringence, crystal orientation function and heat of fusion. A PTT polymer having an intrinsic viscosity of 0.92 dl / g was dried in a hot air dryer at 130 ° C. for 6 hours to a moisture content of less than 30 ppm. The hot air had a dew point of less than -60 ° C. The dried polymer was melted at 260 ° C. using a 30: 1 L / D 1 inch single screw extruder and extruded with a 50 hole spinneret. The extruded fiber is quenched with quench air having a temperature of 16 ° C. to a yarn temperature of less than 50 ° C., passed through a pair of unheated godet rolls in the form of S wraps, and wound by a Barmag SW 46 SSD winder 150 denier yarn was produced. One yarn is spun by a godet roll which winds the yarn at a winding speed of 3500 m / min, the other yarn is spun at a winding speed of 4000 m / min, and the third yarn is wound at a winding speed of 4500 m / min. Spinned. The crystallinity, birefringence, crystal function, and heat of fusion of each yarn were measured. The obtained measured values are shown in Table 1 below.

  The crystallinity, birefringence, crystal function and heat of fusion measured for the yarns shown in Table 1 are significant for partially oriented PTT yarns spun at a winding speed of 3500 m / min or more and a yarn temperature of less than 50 ° C. It shows that it has an orientation degree.

  The boil-off shrinkage after 30 days of the yarn produced in Example 1 was measured to determine the shrinkage ability of the yarn after aging. The yarns were wound up for 30 days after the formation of each yarn and stored under ambient conditions. The boil-off shrinkage of each yarn was measured after 30 days storage. Boil-off shrinkage was measured by the method described above defining the term “boil-off shrinkage”. The boil-off shrinkage after 30 days for each yarn is shown in Table 2 below.

  The results of boil-off shrinkage after 30 days indicate that the PTT partially oriented yarn made by the method of the present invention causes little shrinkage after aging.

  A partially oriented PTT yarn spun by a godet roll that winds the yarn at a winding speed of 4000 m / min was prepared by the method of the present invention, and the boil-off shrinkage of the yarn was measured from the initial formation of the yarn to 30 days from the initial formation of the yarn. The shrinkage stability of the yarn was determined. PTT polymer having an intrinsic viscosity of 0.92 dl / g is dried to a moisture content of less than 30 ppm and the dried polymer is melted at 255 ° C. using a 50 mm diameter barrier screw extruder with an L / D ratio of 25/1 And extruded into 36 filament fibers with a spinneret having a 0.3 mm diameter die hole. The fiber was quenched at a temperature of 21 ° C. to a yarn temperature of less than 50 ° C., passed through a pair of unheated godet rolls in the form of S wraps and wound by a Teijin Seiki winder to produce an 85 denier yarn. . The yarn was spun by a godet roll which winds the yarn at a winding speed of 4000 m / min. The initial boil-off shrinkage of yarns made within 24 hours of yarn manufacture was measured. The boil-off shrinkage of the yarn was measured in the same manner as described above in Example 2. The yarn was aged for 30 days under ambient conditions and then the yarn boil-off shrinkage was measured again. The results are shown in Table 3 below.

  The difference between the initial boil-off shrinkage of the yarn measured and the boil-off shrinkage after 30 days of the yarn is quite small at 6.2%, indicating that the PTT partially oriented yarn made by the method of the invention causes little shrinkage upon aging. It shows that.

  Partially oriented PTT yarns were made by the method of the present invention at a winding speed of 3500 m / min, 4000 m / min, and 4500 m / min and measured for tenacity and elongation at break. The yarn was made by the method described in Example 3 except that the yarn was wound at a winding speed of 3500 m / min, 4000 m / min, and 4500 m / min. Each yarn was measured for tenacity and elongation at break. The results are shown in Table 4 below.

  The measured yarn tenacity and elongation at break indicate that the PTT partially oriented yarn made by the method of the present invention is relatively strong.

  Yarn packages were made by the method of the present invention and the yarn packages were observed over 30 days to detect any shape change induced in the package by yarn shrinkage. PTT having an intrinsic viscosity of 0.92 dl / g was spun into a 32 filament 89 denier partially oriented yarn from a 32 hole spinneret with a 0.25 mm diameter die hole. The filament was quenched to a yarn temperature of less than 50 ° C. with quench air having a temperature of 15 ° C. and a velocity of 0.35-0.45 m / sec. This yarn was passed through a pair of unheated godet rolls operated at a take-up speed of 4000 m / min and taken up on the yarn package. The yarn package weight around which the yarn was wound was 8.1 kg. The yarn package was again inspected for bulge and saddle back at the time of forming the yarn package and 30 days after the formation of the yarn package. The package shape remained substantially unchanged from the time of yarn package formation until 30 days after yarn package formation, demonstrating shrinkage of the yarn and yarn package.

  For comparison purposes, partially oriented PTT yarns were prepared at a winding speed of 2500 m / min by a method not according to the invention and measured for crystallinity, birefringence, crystal orientation function and heat of fusion. The yarn was made by the method described in Example 1 except that the yarn was taken up at a winding speed of 2500 m / min. The crystallinity, birefringence, crystal orientation function and heat of fusion of the yarn were measured. The obtained measured values are shown in Table 5 below.

  The crystallinity, birefringence, crystal function, and heat of fusion measured for yarns as shown in Table 5 are spun at a winding speed of 2500 m / min, and the winding speed of the wound yarn is 3500 m / min or more. It has a significantly lower orientation than the PTT partially oriented yarn spun and wound (as shown in Table 1).

  For comparison purposes, the boil-off shrinkage after 30 days of a PTT yarn made at a winding speed of 2500 m / min (not according to the invention) was measured to determine the shrinkage ability of the yarn after aging. Yarns were made as disclosed in Example 6 above. The boil-off shrinkage after 30 days from yarn formation was measured as described in Example 2 above. The boil-off shrinkage of the yarn after 30 days is shown in Table 6 below.

  The result of the 30 day boil-off shrinkage of the yarn wound at a winding speed of 2500 m / min compared to the PTT partially oriented yarn made by the method of the present invention (as shown in Table 2). Shows that the yarn has a substantial ability to shrink after 30 days of formation.

  For comparison purposes, partially oriented PTT yarn was prepared by a method not according to the invention at a winding speed of 2500 m / min and measured for tenacity and elongation at break. The yarn was made by the method described in Example 3 except that the yarn was wound at a winding speed of 2500 m / min. The yarn was measured for tenacity and elongation at break. The results are shown in Table 7 below.

  The measured tenacity of the yarn indicates that the yarn taken up at a take-up speed of 2500 m / min is relatively weak compared to the yarn spun by the method of the invention (as shown in Table 4). .

1 is a schematic diagram showing an apparatus for spinning and winding multifilament partially oriented yarns. FIG. It is the schematic which shows the undeformed cheese-shaped yarn package cross section. FIG. 2 is a schematic diagram showing a cross section of a yarn package not according to the invention with bulge formation and shrinkage. It is a graph which shows the relationship with the spinning speed which spins the yarn of a crystal orientation function of partial orientation PTT yarn. It is a graph which shows the relationship of the crystallinity with respect to the spinning speed which spins a yarn of a partially oriented PTT yarn. 3 is a graph showing the relationship of 30-day boil-off shrinkage of partially oriented PTT yarn to spinning speed for spinning the yarn. It is a graph which shows the relationship of the birefringence with respect to the spinning speed which spins a yarn of a partially oriented PTT yarn.

Claims (15)

  A yarn comprising a poly (trimethylene terephthalate) yarn having a crystal orientation function of at least about 0.6 and an elongation at break of between 65% and 110%.   The yarn of claim 1, wherein the poly (trimethylene terephthalate) yarn has a heat of fusion of at least about 12 calories / gram, 13 calories / gram, 14 calories / gram, or 15 calories / gram.   The yarn of claim 1 or claim 2, wherein the poly (trimethylene terephthalate) yarn has an initial birefringence of at least about 0.05.   4. The poly (trimethylene terephthalate) yarn has at least about 22%, about 20%, about 19%, about 18% or about 17% initial boil-off shrinkage according to any one of claims 1-3. Yarn.   The poly (trimethylene terephthalate) yarn has a boil-off shrinkage 30 days after the initial boil-off shrinkage of 10%, about 8%, about 6% or about 5% less than the initial boil-off shrinkage. The yarn according to item.   The poly (trimethylene terephthalate) yarn has a meridian two-point small angle X-ray scattering pattern corresponding to a crystalline / amorphous phase lamellar periodicity of about 50 to about 100 Angstroms. Yarn.   The poly (trimethylene terephthalate) yarn has a tenacity of at least 2.5 g / denier, at least 2.6 g / denier, at least 2.7 g / denier or at least 3.0 g / denier. Yarn.   A yarn package comprising the yarn of claim 1. Melt spinning poly (trimethylene terephthalate);
Cooling the melt spun poly (trimethylene terephthalate) to a multifilament yarn having a yarn temperature of less than 50 ° C .; and maintaining the yarn at a yarn temperature of less than 50 ° C., at least about 3500 m / min, at least about Winding a multifilament yarn having a yarn temperature of less than 50 ° C. at a winding speed of 3600 m / min, at least about 3700 m / min, at least about 3800 m / min, at least about 3900 m / min or at least about 4000 m / min A process for forming poly (trimethylene terephthalate) yarns.   The method of claim 9, further comprising winding the yarn on a yarn package. 11. The method of claim 10, further comprising unwinding the yarn from the yarn package; and drawing and false twisting the unwound yarn.   Poly (trimethylene terephthalate) yarn having at most 22 initial boil-off shrinkage, 10% less boil-off shrinkage after 30 days from initial boil-off shrinkage, and elongation at break between 65% and 110% Including yarn.   The yarn of claim 12, wherein the poly (trimethylene terephthalate) yarn has a heat of fusion of at least 12 calories / g.   14. A yarn according to claim 12 or claim 13 wherein the poly (trimethylene terephthalate) yarn has a tenacity of at least 2.5 g / denier.   A yarn package comprising the yarn of claim 12.

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