JP2002509996A - Improving comfort by mixing denier - Google Patents

Abstract

(57) Summary The fiber comfort properties of scalloped oval cross-section longitudinally grooved fibers are modified as a mixture of different dpf and with chain branching, so that filaments of different dpf are drawn simultaneously. It is improved by providing such fibers using a cationically dyeable alkali metal sulfonate isophthalate salt copolyester which can be prepared.

Description

DETAILED DESCRIPTION OF THE INVENTION

TECHNICAL FIELD The present invention relates to a polyester which is a cationically dyeable copolyester composition having an oval cross section decorated with scallops and having the property of being modified by chain branching and capable of being stretched simultaneously. The present invention relates to improved comfort by mixing denier per filament of fiber, and to such a drawing method and products obtained therefrom.

BACKGROUND OF THE INVENTION Polyester is commercially produced on a large scale, primarily from poly (ethylene terephthalate), for processing into shaped articles such as fibers. Synthetic polyester yarns are known and have been used commercially for decades. It is W. H. First proposed by Carothers in US Pat. No. 2,071,251 and then in US Pat. No. 2,465,319 to Winfi
eld and Dickson have proposed poly (ethylene terephthalate), the most widely manufactured and ever used synthetic polymer for textile fibers, and often referred to as the homopolymer PET. Homopolymer PET
Are generally preferred over copolymers because of their lower cost and because their properties are perfectly suited or more preferred for most end uses. However, homopolymer PET requires, for example, special dyeing conditions (high temperatures requiring overpressure) that are not required for nylon fibers, and thus copolyesters have been proposed and for some purposes It is known to be used commercially, for example, Griffeing and Remi
ngton in US Pat. No. 3,018,272, and Hanse
No. 5,171,309 (DP-6335) and US Pat.
No. 250,245 (DP-6335-B) is a cationically dyeable copolyester.

[0003] Polyester fibers are either (1) continuous filaments, or (2) fibers that are discontinuous, the latter often being referred to as staple fibers or cut fibers, and are first extruded by extrusion. Manufactured by forming polyester filaments, and the filaments are processed in the form of continuous polyester filament tows before being converted to staples. An important step in the processing of continuous polyester filaments is "stretching" to increase the orientation of long chain polyester molecules, thereby improving the properties of the filament.

[0004] Primarily, the challenge for synthetic fiber manufacturers is to replicate the advantageous properties of natural fibers, the most common of which are cotton and wool fibers. Most polyester cut fibers are homopolyester PET with a circular cross section and are blended with cotton. Homopolymer PET is hydrophobic, whereas cotton absorbs moisture,
And cotton fabrics have been favored by many over synthetic polymer fabrics. That is because they were convinced that many cotton fabrics were more comfortable to wear than most fabrics of most synthetic polymer fibers, as described above, which were primarily of circular cross-section. Circular cross-section filaments are the easiest and most economical synthetic filaments to spin and dye, which are more expensive to manufacture and more expensive to dye because of the increased surface area This is the reason why practically all synthetic filaments except the special filament have a circular cross section.

[0005] Over the years, homopolymer PET fibers of generally scalloped oval cross section with grooves extending along the length of the fiber have been described by EI du Pont de Nemours.
and offers a significant advantage over both cotton and homopolymer PET fibers of circular cross-section due to the enhanced comfort properties provided by this polyester fiber having a (non-circular) cross-section. ing. Their longitudinal grooves increase moisture-wicking over fibers of circular cross-section
And the fact that moisture is sucked up along the fibers instead of being absorbed is an advantage over cotton. However, further advantages are desired,
And it can be obtained by the present invention.

[0006] Recently, US Pat. Nos. 5,591,523 (DP-6255) and US Pat.
No. 26,961 (DP-6365-A) and co-pending application Ser. No. 08 / 662,804, filed Jun. 12, 1996, now granted.
400) and the corresponding International Publication Nos. WO 97/02372, WO
Nos. 97/02373 and WO 97/02374 disclose inventions relating to conversion to sliver in a worsted or woolen system, and finally to a polyester tow suitable for downstream processes in such systems for fabrics and garments. The disclosures of which are hereby incorporated by reference. The present invention has been made in the course of its work and will be described with particular reference to its value in drawing polyester filaments in tow. The tow disclosed in U.S. Pat. No. 5,591,523 consists essentially of polyester filaments of oval cross section decorated with scallops having grooves extending along the length of the filament, and was identified. A mixture of higher denier per filament and lower denier per filament filaments and was suitable for processing in a worsted or woolen system. In addition to tows that are suitable for processing in worsted or woolen systems, it is desirable to provide polyester fibers for processing in cotton spinning systems that are processed completely differently.

[0007] Cotton spinning system processing is performed on cut staple polyester fibers and, of course, on cotton, which is a natural fiber of the same length as the cut fibers of polyester staples. Contrary to processing in a woolen or worsted system, staple fibers are usually sold and packed in compressed bales.
The bail is opened and the fibers on the pneumatic or mechanical system are conveyed to a carding machine. The carding machine subdivides the tufts of fibers and arranges them into parallel webs of fibers that are formed into continuous slivers as they leave the carding machine. The sliver may then be blended in a draw frame with other fibers, such as cotton, and improve the blend and uniformity along the end through one or more additional draw frames. The sliver is then spun into yarn in a spinning system such as an open-end spinner, air jet spinner, or ring spinner. In some cases, the sliver from the draw frame is further spun into yarn in a ring spinning machine to produce a yarn of the appropriate size (yarn count) and degree of twist prior to forming the fabric. Can be changed to roving to reduce sliver weight.

For example, as disclosed in US Pat. No. 5,591,523 (DP-6255), denier (dpf) per filament (of generally oval cross-section decorated with scallops, and) Is desired and is unexpected in Example 1 of that patent, and undrawn (modified with tetraethylorthosilicate) homopoly (ethylene terephthalate) filaments can be spun. Unstretched filaments of different deniers are spun on the same spinning machine without adjusting the specific draw ratio, and then a homogeneous mixture of these spun filaments is simultaneously drawn on the same tow at the same draw ratio and their different draw ratios dpf could provide filaments with different superior properties (Column 6) , Lines 15-29). The present invention elaborates on this surprising finding and extends it to the simultaneous drawing of bundles of mixed filaments not specified in that patent.

SUMMARY OF THE INVENTION In accordance with one aspect of the present invention, there is provided a mixture of copolyester fibers having a generally scalloped oval cross-section having grooves extending along the length of the fibers,
The copolyester is cationically dyeable due to the presence of from about 1 to about 2.5 mole% of an alkali metal salt of 5-sulfoisophthalic acid, and from about 0.05 to about 0.8
Branched, with mole% chain branching, and the mixture is a mixture of fibers having higher denier per filament, and fibers having lower denier per filament, and higher per filament The lower denier is at least 1.2 times the lower denier per filament; such mol% is the molecular weight of the cationically dyeable salt units or the chain branching units at the molecular weight of the polymer's repeating units. Is divided by 100 and multiplied by 100, for example, the repeating unit for 2G-T is ethylene terephthalate. Such a mixture of fibers may be in the form of a mixture of staple (cut) fibers in various forms, including yarns, as well as fabrics and garments as well as the yarns themselves, and polyester fibers include, for example, polyamides (various In any such form in fibers of other synthetic polymers, including nylons and polyolefins, and / or in mixtures with other fibers, such as natural fibers such as cotton. Is understood.

[0010] Although the terms "filament" and "fiber" are used generically herein and are not generally intended to be mutually exclusive, these general terms are referred to as " It is sometimes modified as a term such as "continuous filament" and "staple fiber".

In accordance with another aspect of the present invention, there is provided a method of drawing a mixture of copolyester fibers of generally scalloped oval cross-section having grooves extending along the length of the fibers, the method comprising: The polyester is cationically dyeable due to the presence of about 1 to about 2.5 mole% of the alkali metal salt of 5-sulfoisophthalic acid and has about 0.05 to about 0.8 mole% chain branching. And the mixture is a mixture of fibers having a higher denier per filament and fibers having a lower denier per filament, and wherein the higher denier per filament is At least 1.2 times the lower denier.

[0012] Preferably, the higher denier is at least 1.5 times the lower denier.

As explained in relation to the stress-strain curve in the present example, no neck stretching has been found, contrary to experience in stretching filaments of homopolymer 2G-T.

DETAILED DESCRIPTION It is redundant to repeat what is already disclosed in the art. As shown, preparation of polyester polymers and spinning of filaments from the polymers are generally disclosed in the art. The drawing of polyester filaments is also described in Nature, by Marshall and Thompson.
Vol. 171 (Jan. 3, 1953), pp. 38-39, in " Drawing Synthetic Fibers ", J. Am . Applied Chem. , 4
(April 1954), pp. 145-153, " The Drawing of Terylene ", and Proc. Roy. Soc. (London), Vo
l. A221, pages 541-557, " The Cold Drawing of High Polymers ".

A mixture of generally scalloped, oval cross-section polyester fibers having grooves extending along the length of the fibers has already been disclosed and identified in US Pat. No. 5,591,523. As such, such mixtures are of higher denier and lower denier. The copolyester fibers according to the present invention should be a mixture of fibers having a higher denier per filament and of lower denier per filament, wherein the higher denier per filament is at least one of the lower denier per filament. Should be double;
Denier per filament is often referred to hereinafter as dpf. As described below, a mixture of denier according to the present invention (sometimes referred to as double denier hereinafter) is compared to a fabric of single denier fiber yarn of oval cross section decorated with similar scallops. Provides improved comfort in the fabric. Although the present invention is not limited to any theory, the inventors have determined that, due to the greater spacing between adjacent fibers, our double denier fibers allow for better water wicking and Are similar in cross section but do not fill together as closely as fibers of the same dpf, since we believe that the fibers of the present invention are not all the same dpf. The improvement is illustrated in the following examples in which the size of the higher and lower dpf fibers is varied and the ratio of the higher dpf: lower dpf is varied. However, preferably the higher dpf: the lower dp
The ratio of f should not be too large, and in particular should not exceed about 5: 1.
For the amount of higher and lower dpf fibers, these may be calculated based on the relative number or weight of fibers. As can be seen in Example 2 below, the ratio of the number of light filaments: heavy filaments, 2: 1 (dpf ratio 1: 2), is based on WVT (Water Vapor Transmission) moisture permeability,
And in% moisture in the fabric, the ratio of the number of light filaments: heavy filaments provides a significant improvement over the nearly 4: 1 and higher, so a small number ratio is generally preferred, preferably about 3: 2. 1 or less. On the other hand, it is recognized that other considerations such as the dpf ratio also affect results including yarn twist and fabric construction. However, Example 2A shows that even with a 10.5 to 1 ratio of the number of light filaments to heavy filaments, MVT and 2
This shows a significant improvement in the% moisture after time over the single dpf comparative example. The examples show so-called "nominal denier" for convenience.
This is because many people do not think in terms of yarns, tows, or other fiber bundles with a mixture of denier, and `` nominal denier '' refers to the total denier of the fiber bundle as the tow, yarn, or book of filament. It is divided by the total number of fibers relative to other bundles of fibers referred to in the specification. In recent years, textile operators have shown increasing interest in the lower dpf obtained from natural fibers such as cotton, including interest in subdenier fibers. The textile operator has less than about 3 dpf (3.3 dtex) of textile fiber d.
Although pf is generally preferred, the present invention is applicable to mixtures of copolyester fibers of any dpf.

With respect to the cross section of the fiber, any of the generally oval cross sections decorated with scallops is applicable. U.S. Pat. No. 5,591,523 describes primarily such a cross section with four grooves extending along the length of the fiber, and a fiber cross section with four grooves is disclosed by Gorrafa in U.S. Pat. No. 4,707,467 and U.S. Pat. Nos. 4,634,6 and 488, more than 20 years ago, and by others, including Franklin, and approximately 10 years later by Clark et al.
No. 25, respectively. Fibers of oval cross section decorated with scallops having 6 and 8 grooves are described in US Pat. No. 5,626,961 and 19
No. 08 / 778,462, filed Jan. 3, 1997 and now granted (Aneja DP-6365-A and Loop DP-6550), are each disclosed and decorated with such scallops. Elliptical fiber cross-sections are also considered suitable according to the invention. It is anticipated and contemplated by the present invention that a mixture of cross-sections, especially a mixture of oval cross-sections decorated with scallops varying the number of grooves, will also provide enhanced comfort. The aspect ratio of the scalloped oval fiber cross-section should generally be at least 1.3: 1 to provide sufficient difference from the circular fiber. As the aspect ratio increases, the benefit of the scalloped elliptical cross-section decreases, and therefore aspect ratios of up to about 3: 1 are generally preferred, depending on other factors such as the number of grooves. It is understood that there is also. Similarly, a generally scalloped elliptical cross-section (eg, not a peanut-type cross-section) where the grooves are not located on the elliptical minor axis is generally preferred for some purposes. The groove ratio herein is the minimum thickness of the filament cross section (ie, at the bottom of the groove on the opposite side of the cross section) divided by the maximum thickness of the cross section (ie, at the bulge next to the cross section). For example, d ₁ / b ₁ and d ₂ / b ₂ described in US Pat. No. 5,626,961 referenced above.

[0017] US Patent No. 5,591,523 (Aneja D), all referenced above.
P-6255) and 5,626,961 (Aneja DP-6365).
-A), co-pending application Ser. No. 08 / 662,804 (Aneja DP-640).
0) and 08 / 778,462 (Roop DP-6550), and International Publication Nos. WO 97/02372, 97/02373, and 97/02.
The only polyester fiber specifically disclosed and illustrated in U.S. Pat. No. 374 was that of a homopolymer PET modified with chain branching. For such modified homopolymer PET, the fibers of the present invention provide a copolyester composition that is cationically dyeable by the presence of about 1 to about 2.5 mole% of an alkali metal salt of 5-sulfoisophthalic acid. Things. Cationic dyeable copolyesters are described in the art, for example, in US Pat. No. 3,018,272 to Griffing and Remington and in US Pat. Nos. 5,171,309 (DP-6335) and Hansen et al. 5,250,245
No. (DP-6355-B). These disclosures are incorporated herein by reference. Such cationically dyeable copolyester compositions for fibers according to the present invention are modified with about 0.05 to about 0.8 mol% of chain branching to simultaneously draw filament mixtures of different dpf according to the present invention. And, if desired, the ability to spin different dpf through different capillary orifices in the same spinneret as disclosed in Example V below should be provided. According to the present invention, the amount of chain branching is preferably at least about 0.2, and preferably is up to about 0.3 mol%. Use of chain branching (ie, a polyfunctional polyester-forming intermediate having more than the two essential functional groups required for polymerization, eg, glycols and dibasic acids, both difunctional) Is disclosed in U.S. Pat. No. 4,092, MacLean et al.
299 and 4,113,704; Mead et al., U.S. Pat. No. 3,335.
, 211, Oxford et al., International Publication No. WO 92 / 13,120, Dun.
US SIR H1275 from Can, European Patent Publication EPA2 294,912 to DuPont (Broaddus et al.), US Patent No. 4,833,030 to Reese.
No. 32, 4,966, 740, and 5,034, 174, Good
No. 4,945,151 to Dley et al. and disclosed in the prior art, such as the prior art referenced and cited therein, such as U.S. Pat. No. 3,576,773 to Varginay. . Some of these references used different terminology, such as viscosity enhancers, for added materials to enhance spinning performance, or for other reasons. Many of this prior art is based on draw-textu
high-speed spinning of continuous filament yarns as feed yarns for such rings, and therefore the continuous filaments are amorphous, as is generally the case heretofore, as is generally preferred for drawing in tow form for conversion to cut fibers. Spin-oriented rather than quality, and cut fibers are particularly interesting and preferred by the present invention. A low shrinkage of about 0.5 to about 3% for a mixture of filaments according to the present invention was spun and spun-oriented for use as a feed yarn for drawing false twist, often referred to as POY. Distinguish our drawn filaments from the higher shrink filaments produced by producing the filaments. The shrinkage is the boil-off shrinkage referred to in Knox, U.S. Pat. No. 4,156,071, column 6, bottom line, and can also be measured by Knox in the manner described there. As shown, US Pat. No. 5,591,523 and International Publication No. WO 9
7/02372 already discloses in Example I the co-drawing of tow of mixed poly (modified with tetraethylorthosilicate) homopoly (ethylene terephthalate) filaments, and surprisingly this is satisfactory, It has already been disclosed that it has been possible to achieve drawn filaments without dark dyeing defects.

Test Procedures Most of the test procedures used are well known and / or described in the art. To avoid any doubt, a description of the procedure used is given in the next paragraph.

Units- Measurements were made using conventional US textile fiber units containing denier, which is in units of meters. To match other practices recognized by longstanding practices, D
The dtex and CPcm equivalents of the PF and CPI measurements are shown in parentheses after the actual measurements. However, for tensile measurements (MOD for initial modulus, and TEN for tenacity), the actual measurement in gpd was converted to g / dtex, and these latter are shown in the table, The stress-strain curve shows the original metric tensile test value on the Y-axis.

The Instron mean stress-strain curve was obtained as an average of ten individual filaments of each type taken from the tow bundle as follows. Ten samples of each type of filament were taken from a tow bundle through a magnifying glass (LUXO Illuminated).
Separation using a Magnifier). The denier (DPF) for each filament of each sample filament was measured using a vibrometer (HP Model 201C Audio).
o Oscillator). The sample filaments were mounted one at a time on an Instron (Model 1122 or 1123) and their stress-strain behavior was measured. 10 breaks were recorded for each filament type, and an average of 10 samples was recorded for each filament type, and thus read from the stress-strain curves of the individual filaments, as is easily understood. The values do not necessarily correlate with the tensile properties calculated and listed as an average in the table.

The dimensions for the fiber cross section were obtained using the following procedure. “Fiber M
microscopy Its Technique and Applicat
ions "in JL Sloves (van Nostrand Co.
, Inc. , New York 1958 No. 180-182), the fiber coupons are substantially identical to the Hardy microtome (Har
dy, USDA circa 378, 1933) and sectioned.
The slices were then transferred to a Super FIBERQUANT video microscope system stage (Vashaw Scientific Co., 3597 Parkway).
Lane, Suite 100, Norcross, Georgia 3009
2) and display at the magnification required for the Super FIBERQUANT CRT. Images of individual flakes of one fiber are selected and the critical fiber size is measured. This process is repeated for each filament in that field to create a statistically significant set of samples, the average of which is shown here.

The aspect ratios and groove ratios were calculated as described in an application filed by Anderson et al. On December 17, 1997 (DP-6585-A).

Relative viscosity (LRV) is the viscosity of a polymer dissolved in (hexafluoro-isopropanol containing 100 ppm of 98% reagent grade sulfuric acid) HFIP solvent.
Viscometers are available from a number of commercial vendors (Design Scientific).
Capillary viscometer available from Co., Cannon, et al. The relative viscosity of centistoke is 4.75 wt.% Of the polymer in HFIP solvent compared to the viscosity of pure HFIP solvent at 25 ° C. % Solution at 25 ° C. The H ₂ SO ₄ used to measure LRV breaks the crosslinks, especially silicon in the case of tetraethyl orthosilicate branching.

Non-acid relative viscosity (NRV) is the viscosity of a polymer that was similarly dissolved, measured, and compared in a hexafluoro-isopropanol solvent but without sulfuric acid. Since the acid is not present, the crosslinks remain intact when the NRV is measured.

Delta RV (ΔRV) is an expression used herein to identify the difference between NRV and LRV measured as described above, and the acid used when measuring LRV Represents the amount of cross-links broken by

Performance characteristics for measuring wicking, drying, and moisture transmission rates were measured on fabrics made as follows. A 1.5 inch (38 mm) cut length of staple fiber will result in a 30/1 cc yarn, such as the 22/1 cc shown, and such yarn will be knitted on a 48-feed single jersey, 22-cut machine. It is. The knitted fabric is washed at 160 ° F. (71 ° C.) for 10 minutes with an aqueous solution containing 30 grams of Merpol HCS and 30 grams of tetrasodium pyrophosphate, rinsed for 5 minutes at room temperature, and for 20 minutes 220
3% OWF Sevron Blue GBR 200%, 4% OWF carrier (Intercarrier) at 15 psi (1 Kg / cm ² ) at a temperature (104 ° C.)
9P) 69-gallon containing 5% OWF sodium sulfate, and 25 ml acetic acid (
260 liter) Klauder, Weldon, Giles Model
Dyeed in a 25 PW Beck dyeing machine, rinsed until clear, and about 15 Fahrenheit in a home laundry-type dryer (Kenmore) for 10 minutes.
Dry at 0 degrees (65 ° C.) and press with dry iron (heated to permanent press set). The resulting dyed and finished fabric was evaluated for aesthetics, "feel", and cover, and for performance characteristics, as follows.

[0027] Moisture feed (wicking rate) is the ability of a material to move water by capillary action. A vertically suspended knitted fabric specimen is immersed in water to a given depth.
At specified time intervals, the distance that the water has risen up the specimen is measured and reported. 1 the longer dimension from the sample is parallel to the wale or machine direction
Four inches by 7 inches (2.5 cm by 18 cm) specimens are conditioned at 70 ± 2 degrees Fahrenheit (21 ° C.) and 65 ± 2% relative humidity for a minimum of 16 hours.
One longitudinal end of each specimen is fastened to the support rack in a vertical position, so the other (free) end is placed in a container, where it is 1.8 inches (4.6).
cm) of distilled and desalted water to a depth of 70 ± 2 ° F. (21 ° C.) while simultaneously starting the stopwatch. The height at which the water rises above the level of water in the container is measured at 0, 5, 10 and 30 minute intervals to the nearest 0.1 inch (0.3 cm). For each sample, every time interval on the specimen (
The average height (expressed in inches) in minutes) is reported.

[0028] Drying rate is the ability of a material to evaporate water. Fabric coupons are saturated in water and weighed at specific time intervals while drying. Over time, water loss is measured and reported. 4 inches x 6 inches (
Three 10 cm × 15 cm specimens were tested at 70 ± 2 ° F. (21 ° C.) and 65 ° F.
Conditioned at a relative humidity of ± 2% for a minimum of 24 hours. The sample is weighed and recorded as dry weight. The specimens are placed in water for 10 minutes in a 250 ml beaker filled with normal tap water, often stirring to remove air bubbles. The coupon is removed from the beaker and excess water is removed by hand drawing and blotting between paper towels, making the wet weight equal to twice the dry weight. The specimen is then hung, while the stopwatch is started. Their weight is recorded at 120 minute intervals over 120 minutes. Moisture percentage is calculated as follows:

Water (%) = [(wet weight−dry weight) / dry weight] × 100

The average moisture (%) at each time interval (expressed in minutes) of the specimen for each sample is reported. Thus, "drying rate" is reported in terms of its percent moisture retained, with lower percent moisture indicating a faster drying rate, and faster drying rates are generally preferred.

[0031] Moisture permeability is the flow of water (moisture) dispersed in air through a material that occurs when the humidity is different on both sides of the material. The test specimen is placed in a cup that covers the water, and the entire assembly is weighed in a controlled atmosphere around 24 hours. The increase or loss in weight is determined by the change in weight per unit area of the test piece (g / 24 hours /
Square meters). The method used was the material's breathable ASTM
Same as E-96 standard test method. However, instead of 50% relative humidity, 55
% Relative humidity is used. Only the immersion method (not the drying method) was used.

The degree of crimp was measured as the number of crimps per inch (CPI) after crimping of the tow. The crimp is represented by many peaks and valleys in the fiber. Ten filaments were randomly removed from the tow bundle and placed loosely (one at a time) in the clamp of the fiber length measurement device. The clamp is manually operated, and while it is still in the clamp, it is first moved to close together sufficiently to prevent drawing of the fibers. One end of the fiber is placed in the clamp on the left side of the measuring device and the other end is placed in the right clamp. Rotate the left clamp to remove any twist in the fiber. Move the right clamp support slowly and gently to the right (while stretching the fiber) until all of the slack has been removed from the fiber without removing any crimps. Using a lighted magnifier, count the number of piles on the front and back of the fiber. The right clamp support is then slowly and gently moved to the right until all crimps have just disappeared. Take care not to stretch the fiber. Record this length of fiber. The degree of crimp for each filament is calculated as follows:

[0033] Total number of piles ―――――――――――――――― 2 × length of filament (not crimped)

The average of ten measurements for all ten fibers is recorded against the CPI (crimps per inch) and the metric equivalent is CPcm.

CTU (crimp take-up) is also measured on the tow, and the length of the tow extended to remove the crimp as described in Anderson et al., US Pat. No. 5,219,582. Was divided by the unstretched length (ie, as it was crimped) and expressed as a percentage.

Product defects are divided into three categories in this specification: 1) Equivalent Fabric Defects (EFD) 2) Dark Dye Defects (DDD) 3) Fragments (SPL)

The first two defects (EFD and DDD) are fibers and masses of fibers that dye more heavily than regular fibers. DDD has a diameter of less than four times the normal (drawn) fiber diameter. EFDs have a diameter that is at least four times the normal fiber diameter. Both defects must be longer than 0.25 inches (6.35 mm). The sample is processed on a roller top type card machine. The sliver is stained in light blue and is visually observed under a lighted magnifier. Fibers that stain more intensely than the bulk of the sample are removed and classified as EFD or DDD,
And counted. Each type of defect is reported as the number of defects per 0.1 pound (0.045 Kg) sliver. Debris is too large a fiber or a mass of fibers. To be classified as debris, this defect is also 0.25 inches (6.35 mm)
Must be longer, but their total diameter is 0.0025 inches (0.063
5 mm). The debris is generated when the staple sample is processed on a flat card, with a flat strip lint.
gather). The flat strip lint is visually observed against a black background. Debris is removed, sorted by size, counted, and expressed based on the weight of the sample. For further details see US Pat. No. 5,591,5.
No. 23.

The present invention is further illustrated in the following examples; all parts, percentages, and proportions are by weight unless otherwise indicated, and the polymer formulation by weight is calculated with respect to the weight of the polymer. You.

EXAMPLE 1 The higher denier (heavy) filaments of the copolyester were
Of dimethyl 5-sulfoisophthalate and 0.20% by weight of tetraethylorthosilicate and contains 0.3% by weight of titanium dioxide and has a relative viscosity of 10.5 LRV and 12.9 NRV, thus 2 .4
Manufactured from ethylene terephthalate having a ΔRV. Approximately 4.6 dpf (5
. 1 dtex) filament was melt spun from the copolyester at 274 ° C. by extruding at a rate of 41.6 pounds / hour (18.9 Kg) and wound on bobbins. The shape of the capillary orifice is described in Application No. 08 / 662,804, filed June 12, 1996 by Aneja (DP-6400),
And three diamonds joined together as shown in FIG. 2 to produce an oval cross-section filament decorated with 4-grooved scallops similar to the filaments described therein. The filament is spun from a spinneret containing 450 such capillaries at a draw rate of 1500 yards / minute (about 1370 meters / minute) and as described by Anderson et al. In US Pat. No. 5,219,582. Quenched to 450 filament total denier 2070 (
2300 dtex).

An oval cross-section filament of the same copolyester and also decorated with 4-grooved scallops, but with a lower denier (lighter) filament of about 2.6 dpf (2.9 dtex) Was similarly melt spun. However, 79.3
Extruded at a rate of pounds per hour (36 Kg / hour) and spun from a spinneret containing 1506 capillaries to give a total bobbin denier of about 3,910 (4350 dtex).
506 filaments were provided.

The as-spun properties for both types of filaments are shown in Table 1A,
FIG. 2 shows the stress / strain curve. The dotted line is for light filaments and the continuous line is for heavy filaments.

[0042]

[Table 1]

In order to have a nominal blending ratio of 60% light fiber / 40% heavy fiber based on filament denier and 75% light fiber / 25% heavy fiber based on the number of filaments, 20% of the lower denier filaments Bobbins (78,312 denier (87,013 dtex), number of light filaments 30,120) and 22 bobbins of higher denier filament (45,540 denier (50,
600dtex) and 9900) of heavy filaments were combined in a creel to form a mixed dpf tow for simultaneous drawing. 85 ° C. at 2.7 × draw ratio
The tow was stretched in a spray stretch of water. The tow is then passed through a stuffer box crimping machine and subsequently loosened at 123 ° C. to a nominal denier of about 1.4 dpf (
50,000 denier (55,555 d) of a homogeneous formulation of 1.6 dtex)
tex) of tow, but containing three times as many light fibers as heavy fibers, in an amount of 60/40 by weight light (approximately 1 dpf and 1.1 dtex) filaments and about 40% heavy (approximately 2dpf) and 2.2dtex) filaments, the finish level was 0.20% OWF, and the product was inspected for product defects. The drawn fiber properties are shown in Table IB.

[0044]

[Table 2]

It is clear that the product quality defect levels were all zero defects, so that the product quality was not adversely affected by simultaneously drawing a mixture of as-spun copolyester fibers of different denier. In addition, draw machine throughput did not decrease due to broken filaments or entrainment.

The tow is cut to a 1.5 inch (38 mm) staple length, and the mixed denier staples are threaded (30/1 cc), and the fabric is knitted as described, the fabric is dyed, and Finishing was evaluated for its comfort / performance and other characteristics and compared to a similar fabric obtained from the product of Comparative Example A described below.

COMPARATIVE EXAMPLE A On the other hand, a similar cross-section and approximately 3.2 dpf (3.6 dtex)
Of filaments from a 14-position spinning machine at 92.4 pounds / hour (41.9
(Kg / hr) by melt-spinning from the same copolyester, but otherwise substantially as described for the heavy denier filaments of Example 1, to a total denier of approximately 67,500 (75,000 dtex
).

The tow was stretched, crimped, and relaxed substantially as in Example 1 except that the stretch ratio was 2.6 ×, also all at 1.4 dpf (1.6 dtex). Approximately 29,500 denier (32,800 dtex) stretched tow of the filament was obtained. The properties of both as-spun and drawn filaments are shown in Table IC.

[0049]

[Table 3]

The single denier filament tow was also cut into staples, yarns, the yarns knitted into a knitted fabric, and the knitted fabric was dyed and finished.

Both fabrics had the following nominal properties: weight about 5.53 ounces / square yard (187 g / m ² ) and wale per inch × cost about 29 × 35 (about 11 × 14 / cm).

The moisture delivery (wicking rate) properties were measured on the fabric and compared in FIG. In FIG. 3, single denier fibers plotted as diamonds, Comparative Example A
The values for the double denier fiber fabric of Example 1 are plotted in squares, and the heights are plotted against time (expressed in minutes) as opposed to the values for. FIG. 3 shows the advantage of the fabric from Example 1 in improved comfort as reflected by its higher moisture delivery value. That is, compared to the single denier filament product fabric of Comparative Example A, the mixed denier product fabric of the present invention exhibited very good moisture delivery values.

The fabric drying rates were measured and compared in FIG. 4 on a similar basis.
FIG. 4 shows the fabric from Example 1 as reflected by the increased drying rate for the mixed denier product fabric of the present invention as compared to the single denier filament product fabric of Comparative Example A. Review the excellent comfort provided.

In contrast to the moisture permeability of the fabric of Comparative Example A (1583 grams / 24 hours / m ² ), the fabric from Example 1 also showed excellent moisture permeability (3630 grams / 24 hours / m ² ). .

Example 2 Table II summarizes moisture vapor transmission (WVT) values and% moisture values for fibers prepared substantially as described for Example 1 (identical polymer composition and denier). However, by adjusting the number of higher or lower dpf filament bobbins used in the drawn creel, the number ratio (
(Light filament / heavy filament). Thus, for 2: 1 light: heavy (item D), the number of 1 dpf fibers (light) was twice that of 2 dpf fibers (heavy).

[0056]

[Table 4]

All fabrics of double denier fiber showed improvement in these measurements over the single denier comparative example, with item D showing the greatest improvement.

Example 3 Filaments of different denier were simultaneously spun from different positions on a substantially identical spinning machine as described in Example 1, except that: 2.0
A copolyester with mol% sodium dimethyl 5-sulfoisophthalate is prepared and has a relative viscosity of 10.2 LRV and 12.4 NR.
V (2.2ΔRV). It was melt spun at 272 ° C. It pushed it out of a total of 15 positions at a rate of 80 pounds per hour per position. 9 positions (5 positions on one side of the machine and 4 positions on the other)
Spun the lower denier filaments (via 1506 capillaries per position). Six positions (three on each side) spun higher denier filaments through 711 capillaries at each position. All of the filaments were spun at a withdrawal speed of 1600 yards / minute and collected in cans as tows, a mixture of light and heavy denier filaments of approximately 56,068 (62,300) total denier. The properties of the as-spun filament are shown in Table IIIA, while its stress-strain curve is shown in FIG. 5, as in FIG.

[0059]

[Table 5]

Twenty-six cans of spun feedstock are mixed together for a total of approximately 1.5 million (170
10,000 dtex) of 463,320 filaments of total denier and stretched, crimped, and loosened substantially as in Example 1 to a nominal effective denier of 1.4 (1.6).
dtex) and has a finish level on the fiber of 0.25% by weight, containing approximately 65 denier and heavy denier filaments.
A final toe size of 0000 denier (720,000 dtex) was obtained. The stretching properties are shown in Table IIIB.

[0061]

[Table 6]

A mixture of as-spun copolyester fibers of different deniers, scrutinizing the product against EFD, DDD, and SPL product quality defect levels, all of which register zero defects It is clear that the stretching was not adversely affected. In addition, draw machine throughput did not decrease due to broken filaments or entrainment.

The tow is also cut into staple fibers, into 22 / cc yarns, the yarns are woven into a fabric, the fabric is dyed and finished, otherwise as in Example 1, its comfort / performance And other fabric characteristics were evaluated as described. A surprising feature is the improved performance properties of fabrics obtained from denier fibers mixed against fabrics made from substantially single denier, which would be relevant here Met.

COMPARATIVE EXAMPLE B On the other hand, a similar cross-section, and approximately 3.4 dpf (3.8 dtex)
0.15 wt.% By extruding the filaments at a rate of 92.4 pounds / hour (41.9 Kg / hour) from a spinning machine having a spinneret containing 1506 tubing, each position being a 13-position spinner. Is produced from a copolyester which is similar except that it was used to produce a polymer having a relative viscosity of 10.3 LRV and 12.9 NRV, and thus 2.6 ΔRV at a draw rate of 1500 yards / min. did. The total denier of the tow using 28 cans for creel was approximately 1.9 million (2.1 million dtex). The tow is stretched at a draw ratio of 2.5 ×, and the tow is stretched, crimped and relaxed substantially as in Example 1 except that the filament is 1.4 dpf (1.6 dtex). Of stretched tow of approximately 767,000 denier (852,000 dtex). The properties of the spun and drawn filaments are shown in Table IIIC.

[0065]

[Table 7]

The drawn tow from each of Example III and Comparative Example B is cut into staples, substantially as described, and turned into 22/1 cc yarns, the yarns are knitted into a fabric, and The fabric was dyed and finished. Both fabrics had the following nominal properties: weight about 6.60 oz / square yard (324)
g / m ² ) and wale per inch × cost about 26 × 32 (about 10 × 13 / cm). Drying speed characteristics were measured on the fabric and compared in FIG. In FIG. 6, the single denier fiber plotted as a diamond (similar to the value for Example IV below), the value for the double denier fiber fabric of Example III compared to the value for Comparative Example B is the solid black. And the moisture content (expressed in percent) remaining in the fabric was plotted against time (expressed in minutes). An advantage of the present invention is the superior comfort reflected by the faster drying speed on the fabric of the mixed denier product of the present invention which shows a significant improvement over the fabric of Comparative Example B. Single Denier Comparative Example B (1232
Showed grams / 24 hours / m ²⁾ with respect WVT obtained these were the fabric was also excellent from the double denier yarn (1797G / 24 hours / m ^2).

Example IV In Table IV, the data is summarized for fibers spun substantially as described in Example III, but differing in number percent and denier. % Of the number of light and heavy fibers in the blend is adjusted by changing the number of capillaries and positions in the spinning machine to produce heavier or less heavy or lighter or less lighter filaments Can be. This 85/15 (light /
For heavy) blends, the inventor has determined that at an output of about 80 pounds / hour / end (36 Kg), withdrawal speed of 1800 yards / minute (1650 meters / minute), and for light filaments, Eleven positions of 1506 capillaries were used and four positions with 711 capillaries per end for heavy filaments. The tow was stretched at a 2.3 × draw ratio and processed into staples, yarns, and knitted fabrics substantially as described in Example III. This 2
The fabric obtained from the heavy denier yarn is a single denier comparative example B (1232).
g / 24 hours / m ² ), and excellent moisture permeability (1464 g / 24 hours / m ² ), and excellent drying speed. Excellent drying rates are indicated by open squares in FIG. 6, which correlates with the excellent comfort reflected by these properties.

[0068]

[Table 8]

As shown in the above examples and comparative examples, different deniers of this copolyester (an ethylene terephthalate copolymer made with sodium dimethyl 5-sulfoisophthalate and modified with tetraethyl orthosilicate) It is possible to produce yarns from two different fibers, wherein fibers of significantly different denier are spun on the same spinning machine and then drawn together (in a single tow) to produce filaments of different dpf And the ultimately obtained fabric (and garment) has superior comfort properties which are better than those of fabrics and garments also made from filaments, all of the same denier. Surprisingly, the present inventors have found that.

Example V A mixed filament was melt spun at 272 ° C from the same copolyester used in Example III. Such mixed filaments are a 50/50 mixture of light / heavy filaments, both are scalloped cross-sections, and both are passed through different capillaries in the same spinneret, each containing 1000 capillaries. Simultaneous melt spinning at a total speed of 23.68 pounds / hour (10.75 Kg) and wound on bobbins at 1800 yards / minute (1650 meters / minute). The spinneret has 516 capillaries to produce heavy filaments, each flow area is 0.0003079 square inches (0.1986 square mm), and 484 capillaries to produce light filaments. And each flow area is 0.0002
It was 224 square inches (0.1435 square mm). The smaller capillaries were placed in the five rings (out of nine) of the spinneret, while the larger capillaries were placed in the four outer rings. The shape of the orifice for the tubule was as used in the previous example for the remaining spinning conditions. Table VA shows the properties of the obtained spun filament.

[0071]

[Table 9]

The 68 bobbins of the as-spun mixed filaments were combined to form a denier approximately 126,000 (140,000 dtex) tow. The tow is stretched, crimped and loosened substantially as described in Example IV,
A homogeneous blend of crimped light denier filaments and heavy denier filaments having a finish level of 0.20% (on the fiber) was obtained. Their properties are shown in Table VB and the nominal denier per filament (ie, the total toe bundle denier divided by the number of filaments) was 1.15 dpf.

[0073]

[Table 10]

The product was processed and then probed for product defects, EFD, DDD, and SPL, all of which registered as zero defects, and thus this copolyester of ethylene terephthalate copolymer containing tetraethylsilicate It is clear that the product quality was not adversely affected by the simultaneous drawing of a mixture of as-spun filaments of different denier. And that was surprising, contrary to previous experience in attempting to process mixed denier filaments prepared substantially similarly from homopolymers without chain branching.

[Brief description of the drawings]

FIG. 1 is an enlarged photograph to show a cross section of a mixture of fibers according to the present invention and is described in further detail herein.

FIG. 2 is a single filament stress-strain curve, which is described more specifically in Example I below.

FIG. 3 provides data to show the improvement in moisture delivery (wicking rate) and dyeing rate for a fabric of the mixture according to the invention as compared to a single denier fiber yarn fabric; This will be described more specifically in an example.

FIG. 4 provides data to show the improvement in moisture transfer (wicking rate) and dyeing rate for a fabric of the mixture according to the invention as compared to a fabric of a single denier fiber yarn, and This will be described more specifically in an example.

FIG. 5 is a single filament stress-strain curve, which is described more specifically in Example III below.

FIG. 6 provides data to show the improvement in moisture transfer (wicking rate) and dyeing rate for a fabric of the mixture according to the invention as compared to a single denier fiber yarn fabric; This will be described more specifically in an example.

──────────────────────────────────────────────────続 き Continuation of front page (81) Designated country EP (AT, BE, CH, DE, DK, ES, FI, FR, GB, GR, IE, IT, LU, MC, NL, PT, SE), OA (BF, BJ, CF, CG, CI, CM, GA, GN, ML, MR, NE, SN, TD, TG), AP (GH, GM, KE, LS, MW, SD, SZ, UG, ZW), EA (AM, AZ, BY, KG, KZ, MD, RU, TJ, TM), AL, AM, AU, AZ, BA, BB, BG, BR, BY, CA, CN, CU, CZ, EE, GE, GW, HU, ID, IL, IS, JP, KG, KP, KR, KZ, LC, LK, LR, LT, LV, MD, MG, MK, MN, MX , NO, NZ, PL, RO, RU, SG, SI, SK, SL, TJ, TM, TR, TT, UA, US, UZ, VN, YUF terms (reference) 4L035 AA09 BB31 BB40 BB55 BB91 DD02 DD18 DD19 EE04 EE08 EE20 HH10 JJ05 4L036 MA05 MA20 MA35 MA39 PA03 PA33 UA16 4L045 AA05 BA10 BA57 DA41

Claims (2)

[Claims] 1. A mixture of co-polyester fibers of generally scalloped oval cross-section having grooves extending along the length of the fiber, wherein the co-polyester comprises from about 1 to about 2.5 moles %, Which is cationically stainable due to the presence of an alkali metal salt of 5-sulfoisophthalic acid, and is branched with about 0.05 to about 0.8 mol% chain branching, and A mixture of fibers having a higher denier per filament, and fibers having a lower denier per filament, wherein the higher denier per filament is at least 1.2 times the lower denier per filament A mixture of copolyester fibers, characterized in that: 2. A method of drawing a mixture of copolyester fibers of generally oval cross-section decorated with scallops having grooves extending along the length of the fibers,
The copolyester is cationically dyeable due to the presence of from about 1 to about 2.5 mole% of the alkali metal salt of 5-sulfoisophthalic acid and from about 0.05 to about 0
. Branched with 8 mol% chain branching, and the mixture is a mixture of fibers having a higher denier per filament and a fiber having a lower denier per filament; and The higher denier is at least 1.10 of the lower denier per filament.
A stretching method characterized by a factor of two.