JPS6242044B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to new polyester filaments and their production which have properties that make them particularly suitable for use as a replacement for cellulose acetate in "flat" yarns. Polyester continuous filaments have been produced industrially for many years and are now produced in very large quantities for use as continuous filament yarns. Continuous filament polyester yarns are often textured to give a "yarn-like" feel, usually by false-twist texturing, but may also be used without texturing, in which case continuous Filament yarns are often referred to as "flat" yarns. Most commercial production is of poly(ethylene terephthalate). The reason for this is the physical properties and economic advantages of this synthetic filamentary material. Most commercially available yarns are processed into fabrics for clothing purposes and are therefore dyed at some stage. However, it is well known that poly(ethylene terephthalate) is more difficult to dye than other filamentary materials such as cellulose acetate, and therefore special dyeing techniques are used industrially. For example, dyeing aids called "carriers" are commonly used to dye homopolymers at high temperature and pressure, or to increase dyeing speed (e.g. by introducing tetramethylene groups) or to introduce dye-accepting groups. In order to
Polyester chemistry has been modified. This is disclosed, for example, in Griffing and Remington US Pat. No. 3,018,272. These special techniques are quite expensive and have long been used, for example, in clothing and home furnishings, to provide useful physical properties and to be boiled (i.e., at superatmospheric pressure and It has been desired to provide poly(ethylene terephthalate) filaments that can be dyed without a carrier in a reasonable amount of time (without the need for equipment suitable for such pressures). Although all physical and chemical properties of a textile yarn should be considered, the most important physical properties are generally the tensile and shrinkage properties. The tensile properties of commercially available (drawn) flat polyester yarns are satisfactory for many textile purposes and are generally of approximately the following order: strength, 4 grams/denier; elongation, 30%;
(initial) modulus, as-manufactured conditions (as-
produced condition), it is 100 g/denier, but in the relaxed state and after boiling, it is 50 to 65 g/denier.
Denier. Normal elongation is indicated, but in determining suitability for specific textile purposes,
Often the modulus is more important. The high modulus of currently commercially available polyester yarns is considered important for many textile purposes. However, cellulose acetate is more preferred for other flat yarn end uses, such as in taffeta and other closely woven fabrics. This is due to the low modulus of cellulose acetate (on the order of 40 grams/denier) and the correspondingly favorable tactile sensation that results.
Currently commercially available polyester flat (drawn) yarns have too high a modulus.
Such polyester yarns are less preferred than cellulose acetate in the end uses mentioned above. However, cellulose acetate has the disadvantage of low strength, especially when wet. For most consumer purposes, commercially available flat yarns should have low boiling shrinkage. Conventionally, fabrics are manufactured using commercially available polyester flat yarns with a boiling shrinkage of about 8 to 10%.
It is then common practice to heat set the fabric to reduce boil shrinkage. Even if currently commercially available polyester textile yarns are heat set, the yarns are not stabilized against shrinkage at temperatures above the heat set temperature. This is because it is a characteristic of these (drawn) polyester yarns that the shrinkage increases markedly with increasing temperature. Conventional commercially available polyester yarns are therefore not truly endowed with thermal dimensional stability in the same sense as in yarns whose shrinkage does not significantly increase with temperature, such as cellulose acetate yarns. It is. It would be desirable to provide a polyester yarn that does not shrink appreciably after boiling so that heat setting to avoid shrinkage during fabric finishing is unnecessary. Low shrinkage tension is also desirable during finishing. As pointed out above, certain properties of traditional polyester yarns (such as modulus)
differs according to whether the yarn is in as-manufactured conditions or already after shrinkage. The latter condition will be referred to as "after boiling shrinkage" in this specification. Properties under both conditions are important. Whereas yarn manufacturers and textile processors are primarily concerned with properties in as-manufactured conditions up to the point where the yarn is boiled (generally when the fabric is scoured and/or dyed). , the end consumer is interested in the properties of the shrunken fabric, ie, after boiling shrinkage. Hitherto, no polyester yarn has been produced industrially with such properties that the modulus of the as-produced yarn is of the same order of magnitude as the modulus of the yarn after boiling shrinkage. When dyeing commercially drawn poly(ethylene terephthalate) yarns, dyeing defects result in large part from the lack of physical uniformity in the yarns. Such defects are more common when dyeing at boiling point (ie at atmospheric pressure), whereas the use of high pressure with a carrier can give a more uniform dyeing. Dyeing defects are readily apparent in taffeta and other closely woven fabrics using flat yarns.
Uniformity can be critical for garment yarns. In the opinion of customers, this is perhaps the most important characteristic. For a polyester replacement to cellulose acetate to be successful, it must be uniformly dyed. This means that the polyester must exhibit good physical uniformity, as discussed later herein. It is therefore desirable to provide a poly(ethylene terephthalate) flat yarn with desirable tensile properties including a suitable relatively low modulus, a modulus not significantly different after boiling, low boiling shrinkage, thermal stability and better dyeability. ,
Although highly desirable for certain end uses, yarns with such desirable properties have not heretofore been commercially produced. Also,
Flat continuous filament yarns do not require post-processing, e.g. drawing or annealing;
It would be economically desirable to produce useful continuous filaments for such yarns directly in as-produced conditions so that they can be used directly to produce fabrics. For many years, polyester filaments have been melt spun and drawn from spinnerets at relatively low speeds of up to about 1000 m/min. These slow spun undrawn filaments were then subjected to a separate drawing operation. That is, in a split process, the filament is spun at a low speed and then subjected to a drawing operation after being wound up, or in a coupled continuous process, the filament is first taken off at a relatively low speed (1000 m/min or less) and then drawn at an intermediate speed. Stretching was performed without winding. Traditionally, drawing has been a step in the industrial production of all flat polyester textile yarns. More recently, polyester filaments have been manufactured on a large scale industrially by being wound by high speed spinning on winders capable of operating at speeds up to about 4000 m/min. This winding machine is supplied, for example, by Barmaag Bammer Machinenfabrik and is, for example, the "SW4S SW4R Spin Draw Machine".
It is described in a pamphlet published around June 1973 entitled ``Machines''. Polyester filaments produced industrially at such speeds are "partially oriented".
"draw-oriented" and as disclosed by Petrille in U.S. Pat. No. 3,771,307.
It is particularly useful as a feed thread for texturing). These yarns were not useful as flat yarns. The strength and modulus of these yarns were lower than commercially available polyester flat yarns, while their elongation and shrinkage were higher. Their shrinkage was generally at least 60%, ie too high for normal textile purposes. A subsequent draw-texturing operation increases strength and modulus and reduces elongation and shrinkage to values previously considered desirable for polyester textile yarns. Traditionally, therefore, drawing has been a step in all industrial production of polyester textile yarns. High-speed spinning of polyester filament at speeds of 3000 to 5200 yards per minute was developed 25 years ago,
It was proposed by Hebeler in US Pat. No. 2,604,689 to provide a low modulus wool-like yarn of grams per denier (110-550 Kg/ <sup>mm2</sup> ). Even higher speed spinning of over 5,200 yards/minute was patented by Hebeler in the US Patent No.
No. 2,604,667, which states that lower spinning speeds result in high shrinkage yarns with completely different properties. High-speed spinning is generally described, for example, by H. Ludewig in his book "Polyester Fibers, Chemistry &Technology".
German edition, 1964, Akademie Verlag and English translation, 1971, John Wiley & Sons, Ltd. and the effects on shrinkage are discussed in Sections 5, 4, 2. Most recently, for example, Chemiefasern/Textil-Industrie, December issue,
As revealed by F. Fourne' in 1976, pp. 1098-1102, interest has turned to high-speed spinning at speeds much greater than 4000 m/min, and traditional winding Instead of speeds on the order of 4000 m/min using a cutting machine,
The emphasis is on providing continuous filament yarns and tows (for staple fibers) with these much higher speed spinning using faster winders. However, rather than using these much larger speeds, around 4000
It would be desirable to use currently commercially available winders operating at m/min to provide useful continuous polyester filaments, as described later herein. This is because the cost of developing and operating a high speed winder with speeds much greater than 4000 m/min is high. There has also recently been interest in reducing shrinkage of the filaments produced by spinning at speeds of about 4000 m/min and modifying process conditions. For example, Chemiefasern/Textil
Industrie), September issue, 1973, pp. 818-821, October issue, 1973, pp. 964-975 and November issue, 1963,
On pages 1109-1114, E. Liska,
Structural changes in polyester fibers due to orientation and annealing (obtained by high-speed spinning) are discussed, and recommendations are made to increase molecular weight (intrinsic viscosity) and denier per filament to reduce shrinkage. Increasing the viscosity has also been proposed, for example in JP-A-49-80322 (Kuraray). This is costly and undesirable for clothing yarns as a replacement for cellulose acetate. As far as is known, poly( The problem of producing poly(ethylene terephthalate) filaments with such good dyeability and acceptable physical properties using a winding machine capable of operating at approximately 4000 m/min has been solved. It has not been previously proposed that this problem can be solved by direct spinning. According to the invention: (1) a flat yarn consisting of continuous filaments of poly(ethylene terephthalate) of 1 to 4 denier/filament, preferably 1 to 2 denier/filament, the yarn comprising: (2) of the filaments; Intrinsic viscosity [η] is 0.56~
(3) the relative disperse dye dyeing rate (RDDR) is at least 0.09, preferably at least 0.11; (4) the modulus (M) measured on the as-produced yarn and at atmospheric pressure; The modulus ( <sub>M2</sub> ) measured after boiling in water for 60 minutes is between 30 and
65 g/denier and the difference (△M) between the modulus (M) measured on the as-produced yarn and the modulus (M <sub>2</sub> ) measured after boiling in water for 60 minutes at atmospheric pressure is 7 g/denier. (5) The amorphous modulus (M A ) is preferably 5 g/denier or less, and (5) the amorphous modulus (M <sub>A</sub> ) is 28 to 38.
g/denier, preferably 28 to 35 g/denier, with the exception that amorphous asmodullus is
Formula M <sub>A</sub> = (0.65/[η]) <sup>0.3</sup> M-X [where X is given by the formula X=530( <sup>ρ -</sup> 1.335)(0.65/[η]) <sup>0.3</sup> , The value of is between 5 and 25] according to the modulus (M), intrinsic viscosity [η] and poly(ethylene terephthalate).
(6) Boiling shrinkage (S) determined from the density (ρ) of 2% to 6%, preferably 2
% to 4%, (7) has thermal stability such that the shrinkage value <sub>S2</sub> is less than 1%, (8) has a density of 1.35 to 1.38 g/ <sup>cm3</sup> , and (9) has a crystal size. (CS) is about 50 to about 90 Å,
There is also provided a flat yarn characterized in that the value depends on the density (ρ) of poly(ethylene terephthalate) according to at least the formula CS1430(ρ−1.335)Å. Preferred yarns also have a strength of from 2.0 to 4.0 grams/denier, especially at least 2.5 grams/denier, such as from 2.5 to 3.5 grams/denier, from 40% to
125%, especially 40% to 100% elongation, strength of 0.7 to 1.2 g/denier at 7% elongation, birefringence of at least 0.045, especially 0.05 to 0.09, 50 Å to 90 Å
and a crystal size of at least 1430 (ρ−1.335) Å, and a density (ρ) of at least 1.35, especially from 1.35 to 1.38. Preferred continuous filaments have a Denier Spread (DS) of less than about 6%, preferably less than 4%, and less than about 1.2%, preferably 0.8%, for example when measured on the same yarn package. Smaller drawing tension fluctuation (draw
tension variation (DTV), and interfilament elongation uniformity (DTV) of less than about 12.5%.
elongation uniformity) (IEU), and low differential filament birefringence of less than (△/20 +0.0055) [where △ birefringence is between 0.045 and 0.09]. Refraction (differential filament birefringence) (△ <sub>95</sub> -
<sub>5</sub> ), it can be used in textile processing without any significant filament breakage. These yarns can be produced directly by spinning using a conventional winder capable of operating at 4000 m/min, giving continuous filaments of sufficient uniformity to be useful in fabrics. The term "flat yarn" as used herein means a continuous filament yarn that is not textured. "Untextured" means that the filament does not exhibit any problematic three-dimensional morphology (e.g. crimping); If present, it is an optical configurational staining defect.
dye defects) and make the filament unacceptable for textile end uses such as taffeta and other closely woven fabrics. Untextured yarns do not exhibit such problematic three-dimensional morphology even after boiling. The following measurements are described for multifilament flat yarns. Modulus (M) and other tensile properties measurements herein were made using a 1 inch x 1 inch flat surface geoyoke clamp with an Alfred Suter toyster head. Instron tester attached
TTB (manufactured by Instron Engineering)
65% relative humidity and 70〓(21
10 inches (approximately 25 °C) at an elongation rate of 60%/min.
Measurements were made with samples of length (cm) and 2 twists/inch (8 twists/10 cm). The modulus (M), often referred to as the "initial modulus", is determined approximately at the beginning of the load-elongation curve when the yarn is stretched at the speeds and conditions described above, with tension on the y-axis and elongation on the x-axis. It is obtained from the slope of the straight line. A modulus (M) in the range of 30 to 65 grams/denier is desirable for tactility. That is, low values tend to give a fabric that is soft and pliable, while high values give a rough and hard feel in contrast to the fabric of cellulose acetate filaments of similar denier. As an alternative to cellulose acetate, <
A modulus of 50 grams/denier is preferred;
Yarns with a modulus of ~50 grams/denier are preferred for this purpose. The yarn of the present invention comprises 7
Preferably, the yield strength, measured by strength at % elongation ( <sub>T7</sub> ), is between 0.7 and 1.2 grams/denier. This value provides sufficient strength during direct wet and dry textile processing to prevent permanent non-uniform elongation (i.e., yielding), which can lead to undesirable dyeing defects. The yarn of the present invention has a difference (ΔM) between the modulus (M) measured on the as-produced yarn and the modulus (M <sub>2</sub> ) measured after boiling in water for 60 minutes at atmospheric pressure.
It is stable to boiling water in the sense that it is less than 7 grams/denier, preferably less than 5 grams/denier. The modulus measured on the as-produced yarn or on the shrunken yarn (after boiling) should be between about 30 and about 65 grams/denier. However, as mentioned above and as pointed out later in Table 1, the modulus of commercially available (drawn) polyester flat yarns is significantly reduced by boiling at atmospheric pressure in the relaxed state. The "modulus" of the yarns of the invention as referred to herein generally refers to that measured on the as-produced yarn;
On the other hand, the modulus after boiling is referred to as "M <sub>2</sub> ". The amorphous modulus (M <sub>A</sub> ) refers to the amorphous orientation and, as pointed out earlier, the normalized value of M (the modulus of the as-produced yarn) M <sub>o</sub> = [0.65/[η ] <sup>0.3</sup> M and then a normalized crystallinity factor, <sup>or</sup> "X value", between 5 and 25 [530 (ρ - 1.335) (0.65/[η]) <sup>0</sup> . <sup>3</sup> ] is calculated. A range of 28 to 38 grams/denier for amorphous modulus (M <sub>A</sub> ) provides a suitable feel similar to that of cellulose acetate filaments of similar denier. Low amorphous asmodulus has improved dyeability (RDDR)
is one of the factors related to Preferred yarns have a relatively low amorphous modulus within this range, preferably less than 36.5, especially less than 35 grams/denier. However, as the amorphous asmodulus decreases even further, filament manufacturing is required to ensure that the shrinkage and thermal stability are such as to provide the filament with a useful flat yarn for the intended end use. It is generally necessary to make the conditions increasingly stringent. This is in contrast to the more moderate conditions generally required to achieve the desired low shrinkage and good thermal stability (but generally with reduced dyeability) for filaments of higher amorphous modulus. . As the amorphous modulus increases, the contraction tension also tends to increase. The shrinkage value herein generally refers to boiling shrinkage (S), which is obtained by suspending a weight that produces a load of 0.1 g/denier on a yarn over a certain length of yarn and measuring its length (L <sub>p</sub> ). Measured by The weight is then removed and the yarn is soaked in boiling water for 30 minutes. Then remove the yarn,
Reload with the same weight and record its new length (L <sub>f</sub> ). Percent shrinkage (S) is calculated by using the formula Shrinkage (%) = 100 (L <sub>p</sub> - L <sub>f</sub> )/L <sub>p</sub> . Low shrinkage is highly desirable for many textile purposes. In contrast to conventional commercially available textile polyester yarns, which are necessarily drawn and annealed, thereby reducing their shrinkage, the yarns of the present invention can be drawn and annealed directly, i.e. in as-produced conditions. It is possible to produce products with reasonably low shrinkage. The smaller the shrinkage, the less the tendency for the physical properties of the yarn, e.g. modulus, to be affected by boiling in the relaxed state, but in order to directly obtain extremely low shrinkage values, e.g. lower than about 2%. increases in difficulty.
The as-made yarn of the present invention with low shrinkage is produced without the need for extremely high spinning speeds such as 6000 m/min. Dry heat shrinkage (DHS) is given only in Table 1 and is measured by performing essentially the same procedure as measuring boiling shrinkage, but instead of soaking the yarn in boiling water for 30 minutes. The difference is that it is subjected to dry heating at 180℃. Thermal stability (S <sub>2</sub> ) essentially follows the method for measuring dry heat shrinkage at 180°C using shrinkable yarns that have been subjected to a boiling shrinkage test and measures the dry heat shrinkage of such shrinkage yarns. It is measured by Under these test conditions, some yarns may stretch. In that case, S <sub>2</sub> will be marked with the symbol E and shown in brackets. For example, the S <sub>2</sub> value for the yarn of Example 2 is (0.2E);
This indicates that the yarn has grown by only 0.2%.
Since it is desirable that the yarn does not shrink significantly after boiling, S <sub>2</sub> is preferably less than 1%. The yarns do not elongate too much, e.g. more than 3%, preferably 2
It is also preferred not to elongate more than %. The contraction tension was measured using a Statham load cell (Statham
Load Cell (Model UL <sub>4-0.5 )</sub> and Statham Universal <sub>Transitioning</sub> (Statham
Universal Tranducing）CEU Model UC <sub>3</sub>
(Gold Cell) at approximately 30°C and 30°C per minute in a furnace using a contraction tension-temperature spectrometer (Industrial Electronics).
of yarn attached at a constant length under an initial load of 0.005 g/denier while increasing the temperature at
Measure a 10cm loop. The maximum value for contraction tension is designated herein by the symbol ST. A low maximum shrinkage tension is desirable for many fabric finishes. The yarns of the present invention generally have a lower maximum shrinkage tension than conventional commercially available textile polyester yarns. The reason is that the latter are stretched at some stage during manufacture. The maximum retraction tension of the yarns of the present invention is typically less than about 0.15 grams/denier. Low maximum retraction tensions are generally more difficult to achieve for very low denier filaments. The contraction modulus (M <sub>S</sub> ) is the maximum contraction tension (ST) divided by the contraction (S) times 100, i.e. M <sub>S</sub>
=ST/S×100. A shrinkage modulus between 1.5 and 3.5 grams/denier represents a desirable balance between shrinkage tension and shrinkage. Intrinsic viscosity [η] is a measure of molecular weight, and C is 0.
[η]=limitlnη <sub>r</sub> /C. where η <sub>r</sub> is the viscosity of a dilute solution of the polyester in hexafluoroisopropanol containing 100 ppm H <sub>2</sub> SO <sub>4</sub> divided by the viscosity of the hexafluoroisopropanol solvent itself containing H <sub>2</sub> SO <sub>4</sub> , Both are measured at 25°C in a capillary viscometer and are expressed in the same units, and C is
Concentration of polyester in grams in 100 ml of solution. For poly(ethylene terephthalate) textile filament, approx.
An intrinsic viscosity of 0.65 is generally preferred. Significantly high viscosities, such as viscosities above 0.68, are undesirable for textile applications and economic reasons.
Therefore, polymer viscosities of 0.66 or less are generally preferred. A value of at least 0.56 is preferred. This is because as the viscosity decreases further, it generally becomes more difficult to obtain filaments with the desired low shrinkage using conventional winders of the type mentioned above. The density of the filament can be measured as in ASTM D1505-63T, and additives such as <sub>TiO2</sub> are added to give the density (ρ) of poly(ethylene terephthalate), which is a convenient measure of crystallinity. should be corrected. The correction used herein is to subtract (0.0087 x % TiO <sub>2</sub> ) from the measured filament density, which yields the density of poly(ethylene terephthalate) (ρ). This value is reported in the Examples. High crystallinity, i.e.
High density corresponds to low shrinkage, which is desirable. Yarns according to the invention preferably have a density (ρ) of at least 1.35 and generally about 1.38 g/cm <sup>3</sup> . These densities are greater than the densities of as-spun yarns produced by low speed spinning or commercially available partially oriented yarns produced by high speed spinning (3000-4000 m/min). The crystallinity of such conventional commercial as-made yarns has been raised to desirable values for textile purposes by drawing and annealing, which can reduce dyeability and therefore Undesirable in inventions. Crystal size (CS) is Scherrer
It is determined by the equation CS=Kλ/β cosθ. In the above equation, K is taken as unit size (Unity); λ is 1.5418 Å, that is, CuK = X-ray wavelength,
θ is the Bragg diffraction angle; β is the instrumental broadening
β <sup>2</sup> =B <sup>2</sup> −b <sup>2</sup> [where B
is the observed broadening and b is the instrumental broadening measured for the ZnO pattern assuming infinitely large crystallites] is the corrected line broadening (all angle measurements are in radians) ). B was measured on the photographic film pattern of the sample using the diffraction arc at 2θ = 17.5° (010 diffraction) and radially along the equator, i.e. at its maximum intensity, HP Klug and LE Alexander. (Alexander) has introduced “X-ray diffraction method (X-ray
Diffraction Procedures, John Wiley and Sons, Inc., New York (1954), Chapter 9. The filament of the invention preferably has the relation:
CS1430 has a crystal size related to fiber density by (ρ−1.335) Å and approximately
It is preferably larger than 50 Å, particularly larger than 60 Å. Generally, the larger the crystal size, the better the tensile properties, with about 90 Å being the maximum that can be achieved in practice. Using stretching technology,
This results in a crystal size smaller than that given by the relation CS1430(ρ−1.335)Å. because,
They can be used in different textile processes, e.g.
This is because it is crystallized in combined spinning/drawing and draw-set-texturing. The relatively large crystal size at moderate density values is an important feature of the filaments of the present invention and is believed to contribute to the thermal stability and, in part, to the improved dyeability of the filaments of the present invention. , which is in contrast to conventional commercially available polyester filaments. Birefringence (Δ) is a measure of the orientation of polymer chain segments. Birefringence is described by Rowland Hill in ``Fibers from Synthetic Polymers''.
It can be measured by the retardation method described in "Synthetic Polymers" (Elsbeer Publishing Co., New York, 1953), pages 266-268. In this method, birefringence is calculated by dividing the measured retardation by the measured thickness of the structure, expressed in the same units as the retardation. Birefringence can also be measured by the fringe method (described below), which is the preferred method for non-circular cross-section filaments and for filaments with high order retardation.
The values reported are averages for 10 filaments measured near the center of each filament (at a point plus or minus 5% from the filament axis). Although the filaments of the invention are suitable for use in textile processing even without drawing, the birefringence of the filaments of the invention is of moderate value (compared to drawn filaments of the prior art). Preferred birefringence values are at least 0.045, which distinguishes the filaments of the present invention from slow spun filaments, while preferred birefringence values are about 0.09 or less, which allows the filaments of the present invention to be drawn This distinguishes it from highly oriented yarns produced by spinning or spinning at higher speeds. A particularly preferred range of birefringence is 0.05 to 0.09. In order for continuous filament yarns to be processed into textiles without significant filament breakage, the filaments must have a low differential birefringence (△ ₉₅ -
₅ ) It is important to have the following. The above request is
In the sense that it is important to minimize the skin on the surface of the filament, we will refer to it as low "skin-core" herein. Such a skin can be detected by the large difference between the birefringence near the surface and the birefringence near the center of the filament; it is therefore important to minimize this difference. Achieving this in practice requires a
%) becomes more and more difficult as the average birefringence value increases. Differential birefringence (△ ₉₅ -
₅ ) is herein defined as the chord-average birefringence (△ ₉₅ ) near the surface of the filament and the chord-average birefringence (△95) inside the filament near its center.
₅ ) is defined as the difference between For example, E. Leitz,
Wetzlar, AG)
Using a double beam interference microscope. The filament to be tested is immersed in an inert liquid of refractive index n _L. The refractive index of this inert liquid differs from the refractive index of the filament by an amount that provides a maximum displacement of the interference fringes of 0.2 to 0.5 of the distance between adjacent undisplaced interference fringes. The value of n _L is measured using an Atsube refractometer corrected for sodium D light (rather than corrected for the mercury green light used in the interferometer in the measurements herein). The filament is positioned in the liquid such that only one of the double beams passes through the filament. The filament is positioned so that its axis is perpendicular to the undisplaced interference pattern and the optical axis of the microscope. Interference fringe pattern, magnification 1000
Record on T-410 Polaroid film at double magnification.
The displacement of the interference fringe is related to the refractive index and the filament thickness by the following equation. d/D=(n- _nL )t/λ where n is the refractive index of the filament, λ is the wavelength of the light used (0.546 microns), d is the displacement of the fringe, and D is the distance of the adjacent undisplaced fringe. the distance between, t and the length of the light path at the point where d is measured (i.e., the thickness of the filament). For each fringe displacement, d, measured on the film, a set of values of n and t is obtained. In order to obtain solutions for the two unknowns, measurements are carried out in two liquids, one of which has a higher refractive index than the filament, according to the criteria given above, Preferably, the other liquid has a lower refractive index than the filament. In this way, for every point across the width of the filament, two sets of data are obtained from which n and t are then calculated. This operation is first performed at each point whose distance from the center of the filament image to the edge of the filament image is 0.05, 0.15, ...0.85, 0.95 using polarized light with an electric vector orthogonal to the filament axis. It will be carried out at This operation gives a chordal average n⊥ refractive index profile. The n refractive index profile is obtained from another interference microscopy measurement performed using polarized light with a photoelectric vector parallel to the filament axis (preferably with a refractive index slightly larger than that of the filament). (use a suitable immersion liquid). The measured value of the distribution of t (path length) in the n⊥ measurement is used to measure n. Birefringence (△) is, by definition, the difference (n-n⊥)
It is. The differential birefringence (Δ ₉₅ − ₅ ) is therefore the difference between the 0.95 and 0.05 points on the same side of the filament image. △ against filament ₉₅ ― ₅
The value is the average of the two _Δ95-5 values obtained on both sides of _the filament image. In all of the above calculations, all one-dimensional dimensions are taken into the same units and, if necessary, are converted to either the magnified units of the photograph or the absolute units of the filament. This method is intended to be applied to filaments with a circular cross section. It is also △ ₉₅
- It can also be applied to filaments with other cross-sectional shapes by changing only the definition of the averaging method to obtain ₅ . The "skin" shown above amounts to about 10% of the fiber's volume. In applying this to non-circular fibers, the portion defined as the skin should similarly contain the outer 10% of the fiber, but the birefringence value of the skin is not truly representative. To ensure this, the fiber must be rotated around its axis through various angles so that sufficient averaging is achieved for the different positions in the fiber skin. The preferred filament for these yarns is △ ₉₅
- Has a △ ₉₅ - ₅ value smaller than ₅ △/20 + 0.0055. For this purpose, Δ is preferably measured by the method of interference fringes. The dyeability of various yarns is compared herein by measuring disperse dye dyeing rate (DDR). Disperse dye dyeing rate (DDR) is defined as the initial slope of the plot of the weight percent of dye in the filament versus the square root of dyeing time, and (if corrected for differences in surface-to-volume ratio) b) It is a measure of dye diffusion coefficient.
This value of disperse dye dyeing rate is based on a circular filament of 2.25 denier/filament with a density of 1.335 g/ ^cm3 , i.e. amorphous 70 mm after boiling.
-34 normalized to circular filament yarn, the relative disperse dye rate (RDDR) is defined by the following relationship: RDDR=Measured DDR [(dpf/2.25)(1.335/ρ)(10
0/100-S)] where ρ is the density of the polymer, dpf is the filament denier, and S is the boiling shrinkage. This RDDR value is more or less independent of the surface-to-volume ratio of the dyed filament and reflects differences in the filamentary structure that affect dye diffusion. Disperse dye dyeing rates were determined using "Latyl" Yellow 3G (Color Index 47020) at 212㎓ for 9 minutes, 16 minutes and 25 minutes with a bath to fiber ratio of 1000:1 and 4% owf (owf = fiber). (by weight) of pure dye. The dye is dispersed in distilled water using 1 g of "Avitone T" (sodium hydrocarbon sulfonate) per dye solution. Approximately 0.1
g of yarn samples were dyed for each time interval, quenched in cold distilled water at the end of the dyeing cycle, washed in cold acetone to remove the dye retained on the surface, air dried, and then washed to the fourth decimal place. Weigh up to. The dye is extracted repeatedly with hot monochlorobenzene. The dye extraction solution was then cooled to room temperature (~70
〓) and dilute to 100ml with monochlorobenzene. The absorbance of the dilute dye extraction solution is measured spectroscopically at 449μ using a Beckman model DU spectrometer and a 1 cm Corex cell. % dye is calculated by the following relationship: % dye = (absorbance/sample weight (g))・(molecular weight of dye/extinction coefficient)・(volume of diluted dye extraction solution/10
00)・100 The ratio of the molecular weight and (molar) extinction coefficient of the dye is
It is 0.00693g. DDR is 9 minutes, 16 minutes and 25 minutes
The slope of the plot of these % dye (weight) measured in minutes versus the square root of staining time (min) ^1/2 . Commercially available poly(ethylene terephthalate) textile yarns (i.e., drawn yarns) are approximately 0.05
It has an RDDR value of , and for boiling dyeing,
Less than 5 g/carrier may be required, whereas the yarns of the present invention have RDDR values greater than 0.09, typically greater than 0.11. Although it is in practice desirable to use leveling agents and/or small amounts of carrier when dyeing the yarns of the present invention, especially at temperatures below the boiling point, such yarns are suitable for normal dyeing cycles. It has the ability to be dyed in deep hues with disperse dyes without a carrier. Preferred continuous filament yarns also have along-end denier
It has excellent uniformity in the length direction as measured by (spread), a small coefficient of variation in drawing tension, and excellent filament-to-filament uniformity as measured by elongation uniformity. These properties give uniform dyeing of the yarn. Denier unevenness is measured with a Model C Worcester yarn unevenness tester manufactured by Zellweger-Worcester. The reported value is the average range of one-dimensional irregularity in yarn mass expressed in percent denier unevenness (DS). %DS
The mathematical definition of is shown below. %DS = maximum denier - minimum denier / average denier x
100 However, the %DS reported is the average of five measurements on a 100 yard long sample measured with the following machine settings: Twist: 1 "Z" TPI Speed: 100 yards per minute on yarn Machine Sensitivity: Half-inert test Evaluation time: 1 minute run Tension: 7 g between tension brake and twisting head Preferred filament yarn is 6 %, especially less than 4%. The variation in drawing tension (DT) along the length of a continuous filament yarn is a measure of longitudinal orientation uniformity and is related to dyeing uniformity. Yarns with high draw tension variation (DTV) give non-uniform and unevenly dyed fabrics. It is desirable to have a low DTV value for uniform staining. Stretch tension was measured using a Statham UC-3 transducer equipped with a UL-4 load cell adapter.
Measurements were made on yarn drawn to a draw ratio equal to elongation at break (%) + 60%/100% using a 36-inch tube heated to 200°C at 100 yards per minute. Stretching is performed while passing at a drawing speed of . Average stretch tension () is the average of 10 10 second interval readings. Draw tension variation (DTV) is defined as the ratio of the standard error (σ) of these 10 readings to the average draw tension ( ) multiplied by 100. DTV (%) = (σ/) x 100 Preferred filament yarns have a DTV value of less than 1.2%, in particular less than 0.8%. Interfilament elongation uniformity (IEU), the filament-to-filament uniformity of longitudinal break elongation of a multifilament (yarn), is a measure of the filament-to-filament uniformity of molecular orientation, which is also a measure of the filament-to-filament uniformity of molecular orientation. Reflects symmetry and uniformity, particularly with respect to quenching, attenuation and snapping. A convenient way to quantify IEU is to differentiate the force versus elongation relationship of an untwisted yarn bundle over the region where the filament breaks. By differentiating the load cell amplifier signal from a typical Instron tensile testing machine, the continuously decreasing force versus time relationship corresponding to filament rupture is determined by the height (H) at half-peak height and the width (W) is converted into a peak characterized by (W). IEU is defined as the ratio of the filament break peak width at half maximum (W) to the elongation at break (E) when E and W are measured in the same units. Differentiation of the load cell amplifier signal from a conventional Instron tensile tester was performed using a resistor/capacitor (R/C) circuit as illustrated in FIG. In Figure 3, the symbol "○" represents the input signal from the Instron tension tester load cell amplifier, and "→" represents the output signal to the Fisher Recorder Series No. 5000 strip chart recorder (0.1 volt full scale). and "〓" represents a ground terminal,
and R ₁ = 100,000 ohm resistor, R ₂ = 10,000 ohm resistor, C ₁ = 1.5 μF capacitor,
And C ₂ = 2.0μ Farad capacitor. Due to the time constants in this device, the crosshead speed (HS) and initial sample length ( _LS ) are adjusted so that the strain rate of the filament at break is approximately constant for all samples being compared. It is important to. To adjust in this way, the length of the sample (L _S ) is adjusted from 6 to
The crosshead speed (HS) was adjusted so that elongation at break (E) occurred after 0.3 to 0.4 minutes. This condition is satisfied by the relation 30(L _S /HS)E40. L _S is the initial sample length and H S is the crosshead speed of the Instron tensile tester, in/min (or corresponding cm/min).
min), and E is the elongation at break (%). Ideally, a complete multifilament bundle or monofilament would have an IEU value of zero. Due to the time constants associated with the differentiator and recording equipment used in this measurement, the IEU of the monofilament was 7.5%. For large filament bundles, IEU values tend to be greater than 7.5%. Preferred multifilament yarns have IEU values less than 12.5%, ie, better than 12.5%. Filaments with desirable properties are approximately
Within the range of 3400-4600m/min, preferably about 4000m/min
A winding speed of m/min can be used for spinning as shown later in the examples. In these examples, the poly(ethylene terephthalate) is passed through an inert gaseous atmosphere (preferably By adjusting the air flow pattern, air flow rate, direction and temperature just below the spinneret, the rate of heat dissipation from the newly extruded filament is controlled by the attenuator. controlled during the session. A significant change in any of the above factors, or a significant change in other factors such as winding speed, spinning temperature, pressure acting on the melt, filament bundle or configuration, or polymer viscosity, will result in a different factor. It will be necessary to make changes to counteract this. Therefore, approximately 4000m/
Suitable for use as flat continuous filament yarn by spinning the continuous filament directly and without drawing or annealing using a normal commercially available winding machine that can be operated at speeds of 1 to 30 minutes. It is also possible to produce desirable filaments with useful combinations of physical properties and dyeability. And although stretching and annealing increase the amorphous orientation and crystallinity, the above relation CS
Stretching and annealing are not desirable process steps because they do not appreciably increase crystal size in relation to conformation density to 1430 (ρ-1.335) Å and therefore reduce dyeability. The terms spinning speed and take-off speed are used herein to refer to the speed of the first drive roll that is (at least partially) wound by the filament. The term spinning speed is more frequently used in the art, which is
Essentially it is the winding speed (ie the speed at which the filament is wound onto the package) in the spinning step of a split process or in a high speed spinning process. coupled spinning drawing
In spin-draw processes, the winding speed is significantly faster than the spinning speed, so to avoid confusion with winding speed, the term take-up speed is sometimes used. The filament is taken off from the spinneret at a speed that is lower than the winding speed.
and to control the take-off speed and draw ratio.
A process in which drawing is performed without using a feed roll is the above-mentioned bonded spinning drawing process. These processes are undesirable. Referring to FIG. 1, a typical high speed spinning apparatus for use in making yarn according to the present invention is shown in which molten polyester is melt spun through an orifice in a heated spinneret block 2. , the filament 1 is cooled in the atmosphere.
It solidifies as. Molten polyester blocks 2
On exit from the filament, the molten polyester is preferably protected from the atmosphere by a metal tube 3 surrounding the filament (insulated from the spinneret and block surfaces by a gasket). The filament passes between the orifice and zone 10, and in zone 10 cooling air is passed through holes in a metal tube 11, preferably symmetrically porous around the filament, to essentially form a douche. Dauchert) U.S. Patent No.
No. 3067458. The filament can, if desired, pass between converging guides 21 arranged to constrain the filament and then rotate into a bath of spin finish, thereby applying the desired amount of finish to the solid filament. contact with a roll 20 applied to the
The filament is then held in contact with finishing rolls 20, and the filament is passed through the next set of guides 25.
through another set of guides 22 directed toward the first
Proceeding to a winding system comprising a drive roll 31, a second drive roll 32, a traverse guide 35 and a drive take-up roll 33, the yarn is interlaced by an interlacing jet 34. According to the invention, about 3400 to 4600 m/min, especially 4000 m/min.
PET yarn spun at a medium speed of m/min is
It has excellent dyeability with an RDDR of 0.09 or more (can give dyed products with a hue similar to cellulose acetate under mild dyeing conditions of 70 to 90°C) and a modulus of 30 to 65 g/denier (same level as cellulose acetate). On the one hand, these yarns were usually found to have excessive shrinkage, which makes them suitable as feed yarns for draw texturing, but not as flat yarns for direct use. . Therefore, the modulus of the yarn spun at a high speed of 3400 to 4600 m/min, especially 4000 m/min, is 30 to 65.
g/denier, while maintaining dyeability at RDDR of 0.09 or higher, and reducing shrinkage by 2 without impairing uniformity.
A reduction to ~6% is required. Although it was known that reducing the filament denier and using a profiled cross section increases cooling properties and thereby increases crystallinity which reduces yarn shrinkage, the filament cross-sectional shape,
The number of filaments and filament denier are always selected by the customer according to the end use.
Therefore, in order to achieve a low shrinkage rate, it is necessary to change manufacturing conditions other than those mentioned above. Also, a polymer viscosity considerably larger than the polymer viscosity [η] of about 0.68 used in commercialized yarn production is effective in reducing shrinkage; High temperatures are required to obtain spinning performance, especially 0.56
When using equipment designed for textile yarn production with a viscosity of ~0.68, polymer degradation may occur. At the same time, high viscosity tends to increase the modulus of the yarn and decrease the dyeability of the yarn. Textile viscosity [η] of 0.56 to 0.68 for good runnability on textile yarn spinning equipment and to obtain good dyeability with modulus of 30 to 65 g/denier and RDDR value of 0.09 or higher. It is necessary to spin within a range. In general, it is desirable to avoid the expense of retrofitting the main equipment, ie, to use quenching equipment that is already available today. Examples 3 to 10 and
Cross flow quenching is used as illustrated in Example 12, and in other cases radial flow quenching is used as illustrated in Examples 1, 2 and 11. However, in the present invention, while obtaining excellent denier uniformity (eg, Examples 1 and 2), the length of the tube protecting the freshly extruded filament was adjusted to reduce shrinkage. Once a quenching method is selected, the effect of capillary diameter and length on yarn shrinkage and uniformity is next considered. It is known that using a capillary diameter (D) greater than about 0.5 mm results in a large spinning draft ratio (D _R ). here,
The spinning draft ratio (D _R ) is defined as the ratio of the take-up speed (V) to the extrusion speed (V ₀ ), ie, _DR = V/V ₀ ∝(diameter) ² /DPF. Using a large spinning draft ratio increases spinline tension and crystallinity and reduces shrinkage. However, such large capillary diameters are at the same time particularly
For 4 denier thin filament, △ ₉₅ -
Larger skin as measured by _5-
It was found that a core structure was formed. Also, if a large capillary is used to spin filaments of small denier, the spinning may become unstable and the denier uniformity and mechanical properties may deteriorate. During melt extrusion of the polymer, the capillary diameter should be small and the length to diameter ratio (L/D) The combination of having a large value is very important. The importance of using a long, thin capillary with a large L/D ratio is not mentioned in any prior art document to the inventor's knowledge. This is one obvious difference between the methods taught in the prior art and the present invention. In embodiments of the present invention, for spun filaments of 1 to 4 denier, the capillary diameter ranges from 0.2 to 0.5 mm, with an L/D ratio of 4:1 being generally preferred, especially when the capillary diameter is 0.2 mm. ~0.5mm
on the relatively high side of the range, for example Example 7 (0.5 mm) or Example 6 or 11 (0.38 mm).
This is the case in cases such as mm). In the examples, L/
The lowest D ratio was in Examples 3, 10, or 12.
1.4, and as evidenced by the physical properties of the yarns of these examples, this L/D ratio of approximately 1.4 is satisfactory for the combination of filament requirements of the present invention and carefully selected spinning conditions. It is. Although slightly lower L/D ratios, such as about 1.3, can be used in some cases, significantly lower L/D ratios yield filaments with the desired combination of physical properties in the present invention. That is no longer possible. For example, the filament of the present invention cannot be produced with an L/D ratio of 1 (the length of the capillary is approximately the same as the diameter). That is, the present invention has a small denier (1 to 4
It is desirable to avoid using large diameter capillaries to make filaments. One reason is that a large capillary diameter means a large spinning draft (the ratio of the orifice diameter to the filament diameter, or the ratio of the take-up speed to the extrusion speed from the orifice). It is from. As the spinning draft increases, it becomes more difficult to obtain small denier filaments with the desired uniformity. Some prior art methods use high viscosity polymers and large spinning drafts to obtain high denier filaments with low shrinkage at speeds on the order of 4000 m/min;
It is not suitable to obtain homogeneous, small denier filaments using polymers with normal viscosities [η] of the order of 0.65. In the case of small denier filaments, if the spinning draft is excessive, the filaments will become uneven, which will impair the workability for spinning and textiles, and will cause many yarn breakages, which will impair the aesthetic appearance of textile products and make them unacceptable as products. result. The filament also has a tendency to crimp, making it unsuitable for use in flat yarns. Another reason for using a capillary with a small diameter and high L/D ratio is that this combination
This is because, when the molten polymer passes through the capillary under high pressure used during spinning, more shear heat is generated on the surface of the molten polymer than when the diameter is large and the L/D ratio is small. That is, when the extruded polymer exits the capillary and begins to cool, the temperature at its periphery is lower ( high shear heat), which is advantageous. It is obvious that when a molten polymer is attenuated, cooled and solidified to form a solid filament, its periphery cools faster than its center. If the outer periphery of a filament being drawn at high speeds on the order of 4000 m/min is cooled faster than the center, undesired molecules will cross the filament's cross-section unless some measure is taken to avoid this. Differences in orientation may occur. This difference in orientation is called the skin-core effect, and the filament has a significantly different degree of orientation at its outer periphery (skin) than at its center (core). Filaments with high skin-core values are undesirable because their non-uniformity makes them susceptible to breakage and/or crimp. This is why a moderate shear heat is important to obtain the filaments of the present invention. After selecting the spinneret capillary dimensions, the spinning temperature (defined by block temperature and pack pressure) is selected. Lowering the spinning temperature increases the melt viscosity and crystallization rate of the extruded polymer and reduces yarn shrinkage. However, lowering the spinning temperature too much increases the skin-core structure. The skin-core structure reduces tensile strength, increases filament breakage, and increases yarn direction tension due to deterioration of longitudinal denier uniformity. If the spinning temperature is excessively high, the spinning temperature will be 2 to
It is not possible to obtain the desired low shrinkage of 6%. The preferred spinning temperature to obtain a particular desired yarn is highly dependent on the particular polymer used and its method of preparation, but for the polymers used in the examples a spinning temperature in the range of 290-310°C is preferred; , adjust the block temperature to 290-310℃,
This can be achieved by adjusting the pack pressure between 1000 and 7200 psig. Control of spinning temperature is important to control the uniformity of yarn shrinkage. The shrinkage rate can be further reduced by improving the cooling rate. This cooling rate improvement is achieved by splitting the filament bundles and increasing the spacing between the filaments as in Examples 4 and 7 and by using higher air flow rates as in Examples 2, 3 and 10. can be achieved. However, the requirement for high cooling rates must be balanced with the requirement for good radial uniformity and denier uniformity. Cooling too quickly can increase yarn direction tension too much and reduce filament uniformity. Finally, the take-up speed needs to be adjusted to obtain yarn uniformity. It is preferred to use a multi-guide and triaxial winding as in Example 1 or a system that achieves a similar level of adjustment. In summary, the denier/filament, cross-sectional shape and number of filaments are what the customer chooses to obtain the desired woven fabric, so these parameters can be controlled to obtain the desired shrinkage of 2-6%. I can't do it like that. Regarding the selection of the polymer viscosity [η], typical viscosities commonly used in the production of textile yarns are selected in order to obtain good runnability. The shrinkage rate of yarn is
Reduced by selecting and balancing small capillary diameter of 0.2-0.5 mm, L/D greater than 1.4, moderate spinning temperature of 270-310 °C and effective cooling using cross-flow or radial quenching. . At this time, the length of the protective tube below the spinneret tube and the air flow rate of about 15 to 50 SCFM/fiber bundle are adjusted to give a yarn shrinkage of 2 to 6% and about 8%.
Achieve a denier variation of less than about 6%, preferably less than about 6%. The invention is further illustrated in the following examples. Properties and manufacturing conditions are presented in summary form in Table 2 at the end of the detailed description of the invention. Weight percentages of titanium dioxide are calculated based on total weight. Birefringence was not measured for each sample, but for all examples
It is thought to be between 0.05 and 0.09. Figure 2 shows
FIG. 3 is a diagram plotting the boiling shrinkage values for the yarns of the examples against the spinning speed. Prior art polyester spun at the same speed gave yarns with greater shrinkage. This high shrinkage is usually later reduced by a drawing/annealing process, which is undesirable for producing the dyeable, thermally stable yarns of the present invention. EXAMPLE 1 Poly(ethylene terephthalate) having an intrinsic viscosity of 0.66 was measured at 4500 yd/min (4115 m/min) in equipment essentially as described above and illustrated in FIG.
The fibers were spun using a pack pressure of 3500 psig through a spinneret block at 298°C and a spinneret capillary with a diameter (D) of 9 mils and a length (L) of 50 mils at a winding speed of 1.02 denier/filament. 68
A filament flat yarn (circular cross section) is formed. The discharging filament is protected by a hollow tube approximately 2 inches long and then exposed to a radially inwardly flowing air stream at room temperature at a rate of 25 standard cubic feet per minute (SCFM). The set yarn is contacted with a finish roll, the finish is the same as described in Example 1 of Burks and Cooke, U.S. Pat. interlaced and wound. It has good dyeability (RDDR 0.1), amorphous modulus (M _A ) of 32.4 g/denier, modulus (M) of 51.4 g/denier, and boiling shrinkage of only 3.6%. It's worth attention. Thermal stability is excellent as shown by the dry heat shrinkage (S ₂ ) after boiling of only 0.3%. The modulus (M ₂ ) after boiling is 54.5 grams/
denier, so the difference ΔM between M and M ₂ is only about 3 grams/denier. X value (difference M _o
- M _A ) is about 19 grams/denier, or 5
Between 25 and 25. The shrinkage modulus (M _S ) is 3.22 grams/denier. Crystal size (CS) is 71
and the density of the polymer (ρ) is 1.3707,
Therefore CS<1430(ρ−1.335), i.e. CS>50
It is. Birefringence (△) is 0.0883. Example 2 A 68 filament flat yarn of 1.52 denier/filament with good dyeability and other properties was prepared with a polymer having an intrinsic viscosity of 0.65, a block temperature of 296°C, and a pack pressure of 4900 psig.
, and the filament produced has a length of about 4
protected by a hollow tube of 50 inches
It was spun as in Example 1, except that it was cooled with air at standard cubic feet per minute. The shrinkage is 4.7%, and the thermal stability is excellent ( _S2 elongation 0.2). Example 3 40 filament yarn with 1.92 denier/filament and good properties, with intrinsic viscosity 0.65
was spun essentially as in Example 1, but using a block temperature of 295°C, a pack pressure of 3800 psig, and a spinneret capillary of 12 mils in diameter and 17 mils in length, and the resulting filaments were: 30 downwards from the spinneret by a cross-flow of air at a rate of 41 standard cubic feet per minute.
Cooled down to an inch long distance. The polymer contained 0.3% by weight titanium dioxide pigment. Many of the properties of the polyester yarn of the present invention (Example 3), such as shrinkage (S), thermal stability ( _S2 ), modulus and elongation, are better than those of cellulose acetate than ordinary (i.e. conventional) polyesters. To show a closer approximation, some of the properties of the flat polyester yarn of Example 3 were compared with those of the prior art drawn polyester yarn (control) and the prior art cellulose acetate yarn.
Compare in table. On the other hand, polyester yarns have excellent strength and, importantly, in contrast to cellulose acetate, their strength does not decrease even when wet. The yarn of Example 3 has an RDDR of 2-3 times that of regular polyester and can be dyed using commercial pressure dyeing equipment commonly used for cellulose acetate without a carrier at reasonable speeds. It can be dyed by boiling. This is in contrast to ordinary polyester, which dyes slowly and in practice using high pressure equipment. Cellulose acetate is much easier to dye than either of these polyester yarns and is approximately
Can be dyed at 70℃. The modulus of regular polyester decreases by almost 50% when the yarn is boiled, whereas the modulus of the yarn of Example 3 is essentially the same before and after boiling. The high shrinkage of regular polyester is a serious economic disadvantage in fabric processing, and the lack of thermal stability (high
_S2 ) may cause customer dissatisfaction. The shrink tension of the yarn of Example 3 is significantly lower than that of regular polyester, which is important in fabric finishing.

[Table] It becomes sea urchin.
Example 4 Does not contain titanium dioxide, 3.20 denier/
A 34 filament flat yarn of filaments and having similar good properties was spun more or less as in Example 3, but using two spinnerets giving 17 filaments each and cooled by cross-flow air at a rate of 31 standard cubic feet per minute, with a block temperature of 292°C and a pack pressure of 4500 psig.
The polymer was spun through a spinneret capillary with a diameter of 10 mils and a length of 40 mils. Example 5 A 34 filament flat yarn of 1.49 denier/filament containing 0.2% titanium dioxide was prepared using the method of Holland, US Pat. No. 2,939,201.
The filament has a trilobal cross-section with a modification ratio of 1.75, as described in U.S. Pat. No. 3,859,031 to Hawkins, and A plug with a hole drilled in it is inserted into the counterbore of the spinneret, and the restriction on the hole in the plug insertion part is the size of the capillary used in Example 1, and the block temperature is
The yarn was spun essentially as in Example 3, except that the temperature was 302°C, the pack pressure was 2200 psig, the air flow rate was 44 standard cubic feet per minute, and a different finish was used. The yarn properties were good as shown in Table 2. EXAMPLE 6 A 34 filament flat yarn of 3.88 denier/filament was prepared with the filaments having an octalobal cross section and a modification ratio as described in McKay U.S. Pat. No. 3,846,969.
1.2, Cobb U.S. Patent No. 3095607
Using a metering plate as described in the issue, using a 15 mil diameter and 72 mil length capillary, above the bottom plate containing an orifice of appropriate design for the filament of the octalobal, and at the block temperature. 296℃, pack pressure is 3700psig, and air flow rate is
It was spun in essentially the same manner as in Example 3, except that the polymer was 31 standard cubic feet per minute and contained no titanium dioxide. In Example 7, the normalized modulus (M _o ) is larger than the modulus (M) because a low viscosity polymer is used, but the amorphous modulus and dyeability of the yarn are similar to those in the other examples. It will be noted that they are the same. Example 7 A 34 filament flat yarn was spun essentially as in Example 4, but using a lower intrinsic viscosity (0.59) polymer and 0.9% titanium dioxide pigment, a block temperature of 290°C,
1100 psig pack pressure, 20 mil diameter and 80 length
A 2.16 denier filament was produced using a mill spinneret capillary, 19 standard cubic feet/min/bundle of crossflow air, and different finishes. Example 8 1.84 denier/40 with good properties of filament
The filament flat yarn was prepared with a high polymer intrinsic viscosity (0.67), a block temperature of 298°C, a pack pressure of 3200 psig, a spinneret capillary as in Example 4, and a 31 standard cubic feet/ The yarn was spun as in Example 3, except that 100% of air was used. Example 9 A 40 filament flat yarn was prepared with an intrinsic viscosity of
4750 yd/min (4343m/min) from 0.65 polymer
A filament of 1.86 denier was obtained having the useful properties shown in Table 2. Its dyeability is not as good as that of circular yarns of the same denier and lower amorphous modulus spun at slower speeds. Example 10 80 filament flat yarn of 1.88 denier/filament was spun at 5000 yards/min (4572 m/min).
The fibers were otherwise spun essentially as in Example 3, except that the pack pressure was 4200 psig. Its properties are shown in Table 2. Example 11 80 filament flat yarn of 1.86 denier/filament was spun at 4500 yards/min (4115 m/min).
from a 0.65 intrinsic viscosity polymer with 0.3% titanium dioxide (min) through a spinneret capillary of 15 mils in diameter (D) and 60 mils in length (L) using a spinneret block at 290°C and a pack pressure of 3400 psig. , but otherwise spun essentially as in Example 1, except that the air flow rate was 17.5 standard cubic feet/min/bundle and a different finish was used. Its properties are shown in Table 2. The strength is 3.71 g/denier, which is very good. Example 12 Poly(ethylene terephthalate) was prepared from ethylene glycol, terephthalic acid and 2-ethyl-2-(hydroxymethyl)-1,3-propanediol in an amount of 0.001146 moles per mole of terephthalic acid, and the block temperature was 293°C. and the pack pressure was 7200 psig, and the resulting filament was cooled by crossflow air at a rate of 37.5 standard cubic feet per minute over a distance of up to 54 inches below the spinneret. A 40 filament flat yarn of 1.83 denier/filament was spun as in Example 3. Compared to the yarn of Example 3, the strength and birefringence are lower, but the elongation is higher and the yarn shows good dyeability. However, the strength of 2.14 g/denier is greater than that of acetate. The longitudinal uniformity and filament-to-filament uniformity of these flat filament yarns are
Shown in the table. The yarns of Examples 1-4 and 11 are particularly preferred for the production of fabric structures requiring good dyeing uniformity, such as taffeta and other closely woven fabrics. Example 6 has acceptable uniformity, but _a slightly higher differential birefringence _Δ95-5 than required for good textile processability. Other filament yarns may be acceptable for textile and home furnishing end uses where dye uniformity requirements are not as critical as in, for example, taffeta. These flat yarns are direct-use yarns, i.e., they are in contrast to currently commercially available partially oriented yarns that are already draw-textured before being used in the fabric.
It can be used in textile fabrics without stretching, annealing or heat setting. These flat yarns exhibit useful physical properties, including dyeability and thermal stability, shrinkage, shrinkage tension, and modulus before and after shrinkage, that are significantly different from currently commercially available, as-manufactured polyester flat yarns. It has a combination of Modification of the flat yarn can be carried out depending on the desired end use. The yarns of the present invention respond favorably to air jet texturing and provide looped yarns while retaining good dyeability.
On the other hand, dyeability is reduced if stretching is done as part of the texturing operation. The yarns can be crimped, if desired, mechanically, such as by knitting-unknitting, gear crimping, stuffer boxing, and other methods.

【table】

【table】 [Brief explanation of the drawing]

FIG. 1 illustrates a typical process for high speed spinning for use in making yarns according to the present invention. Figure 2 shows the boiling shrinkage (S) of the poly(ethylene terephthalate) yarn of the example in y
1 is a graph plotting on the x-axis the spinning speed in m/min used to produce such a yarn. FIG. 3 is a circuit diagram for use in conjunction with uniformity testing (IEU) on continuous filament yarns.

Claims (1)

[Scope of Claims] 1. (1) A flat yarn consisting of continuous filaments of poly(ethylene terephthalate) of 1 to 4 denier/filament, the yarn comprising: (2) an intrinsic viscosity [η] of the filament of 0.56 to 4;
0.68; (3) the relative disperse dye rate (RDDR) is at least 0.09; and (4) the modulus (M) measured on the as-produced yarn and boiled in water for 60 minutes at atmospheric pressure. The modulus (M ₂ ) measured later was 30~
65 g/denier and the difference (△M) between the modulus (M) measured on the as-produced yarn and the modulus (M ₂ ) measured after boiling in water for 60 minutes at atmospheric pressure is 7 g/denier. (5) Amorphous modulus (M _A ) is 28 to 38.
g/denier, where the amorphous modulus is expressed by the formula M _A = (0.65/[η]) ^0.3 M-X [where X is the formula ^X = 530 (ρ-1.335) (0. 65/[η]) ^{0.3 ,} and the value of (6) has a boiling shrinkage (S) of 2% to 6%, (7) has thermal stability such that the shrinkage value S ₂ is less than 1%, and (8) has a density of 1.35 to 6%. 1.38 g/cm ³ , (9) crystal size (CS) is about 50 to about 90 Å,
and a value dependent on the density (ρ) of poly(ethylene terephthalate) according to at least the formula CS1430(ρ−1.335) Å. 2. The flat yarn according to claim 1, having a shrinkage modulus (M _S ) of 1.5 to 3.5 g/denier. 3. The flat yarn according to claim 1 or 2, having a boiling shrinkage (S) of about 2% to about 4%. 4. The flat yarn according to any one of claims 1 to 3, having a birefringence of about 0.045 to about 0.09. 5 Claims in which the difference (ΔM) between the modulus (M) measured on the as-produced yarn and the modulus (M ₂ ) measured after boiling in water for 60 minutes at atmospheric pressure is 5 g/denier or less 1st~
4. The flat yarn according to any one of Item 4. 6. A flat yarn according to any one of claims 1 to 5, having a relative disperse dye dyeing rate (RDDR) of at least 0.11. 7. According to any one of claims 1 to 6, the denier per filament is 1 to 2.
Flat yarn. 8 Amorphous modulus (M _A ) is 28-36.5
Flat yarn according to any one of claims 1 to 7, which is g/denier. 9. The flat yarn according to any one of claims 1 to 8, having a strength of 2.0 to 4.0 g/denier. 10. The flat yarn according to any one of claims 1 to 9, having an elongation of 40 to 125%. 11 Amorphous modulus (M _A ) is 28-35
g/denier Claims 1 to 10
A flat yarn according to any of paragraphs. 12. The flat yarn of any of claims 1 to 11, having a denier variation (DS) of about 8.1% or less. 13. The flat yarn of any of claims 1-12 having a draw tension variation (DTV) of less than about 1.2%. 14 Interfilament elongation uniformity (IEU) is 12.5
%. Flat yarn according to any one of claims 1 to 13. 15 Differential birefringence (△ _95-5 ) is expressed by the formula △ _95-5 △/
20 + 0.0055, where Δ is from about 0.045 to about 0.09. Flat yarn according to any one of items 1 to 14. 16. Flat yarn according to any one of claims 1 to 15, having a yield strength of 0.7 to 1.2 g/denier, measured by strength at 167% elongation ( _T7 ).