JP2003013333A - Polyester composite uneven yarn - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyester composite uneven yarn suitable for obtaining a fabric assuming an excellent natural feeling and spunized appearance, even a good dry feeling and excellent wrinkle recovery properties. SOLUTION: This polyester composite uneven yarn is obtained by compounding and combining (A) polyester thick and thin fibers with (B) a polyester drawn fibers. The polyester thick and thick fibers (A) have >=80% elongation (ELA), <=50% elastic recovery ratio at 10% elongation (ERA), <=5.89 GPa elongational modulus of elasticity (EMA), >=25% crystallinity (XpA), <=3% boiling water shrinkage percentage (BWSA) and <=0.44 mN/dtex thermal stress at 160 deg.C (TSA). The polyester drawn fibers (B) have <=40% elongation (ELB), >=7.85 GPa elongational modulus of elasticity (EMB), >=5% boiling water shrinkage percentage (BWSB) and >=0.88 mN/dtex thermal stress at 160 deg.C (TSB). The polyester composite uneven yarn has respective peak values (Pmax1 and Pmax2 ) present at 4-10 cm period and 50-150 cm period on a spectrograph obtained by normal tests and the peak value ratio (Pmax1 /Pmax2 ) thereof is 1.0-4.0.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel polyester composite fluff that exhibits excellent natural feel, dry feel and spanize appearance and is excellent in wrinkle recovery.

[0002]

2. Description of the Related Art It has been well known that a non-stretched polyester yarn is incompletely stretched to obtain a fluffy yarn. Naturally, the more the unevenness is emphasized, the more the characteristics such as the texture become stronger, but if the unevenness is emphasized too much, the natural feeling is impaired or the unoriented portion of the low orientation remains. There is a problem that the handling property and the mechanical property are deteriorated due to this.

To solve this problem, Japanese Patent Publication No. 3-77
In Japanese Patent Publication No. 304, there is proposed a fluffy yarn in which the thick portion of the fluffy yarn is in a special dispersed state, and the value of the cycle 50 cm on the spectrograph obtained by the normal test is 1/2 or less of the maximum value as a yarn. ing. Certainly, this fluffy yarn has improved mechanical properties and handleability, but the texture is still insufficient depending on the application, and further improved natural feeling,
It is desired to develop a fluffy yarn having a dry feeling and a spanned appearance.

In order to meet such demands, the present inventors have
Previously, a polyester fluff yarn having a specific dispersion state in the length direction of the yarn was proposed. Although it is true that this fluffy yarn can meet the above requirements, it may be difficult to remove wrinkles when they are wrinkled when worn or stored, and further improvement is necessary. found.

[0005]

SUMMARY OF THE INVENTION The present invention has been made on the basis of the above-mentioned prior art, and its object is to provide an excellent natural feeling, a spanned appearance, a good dry feeling, and a wrinkle recovery property. Another object is to provide a polyester composite fluff that is suitable for obtaining an excellent fabric.

[0006]

According to the research conducted by the present inventors, the object of the present invention is to obtain an elastic recovery rate (ERA) of 50% or more at an elongation (ELA) of 80% or more and 10%. % Or less, the elongation rigidity (EMA) is 5.89 GPa (600 k
g / mm ² ) or less, crystallinity (XpA) is 25% or more,
Boiling water shrinkage (BWSA) is 3% or less, thermal stress (TSA) at 160 ° C is 0.44 mN / dtex (50 mg
/ De) or less polyester thick fibers (A), elongation (ELB) 40% or less, elongation rigidity (EMB) 7.
85 GPa (800 kg / mm ² ) or more, boiling water shrinkage (BWSB) 5% or more, thermal stress (T
SB) is a polyester composite fluff that is a composite blend of a polyester drawn fiber (B) having a SB of 0.88 mN / dtex (100 m / de) or more, and the yarn is on a spectrograph obtained by a normal test. , Cycle 4-10
cm and the peak value (P
_max1 and P _max2 ) and their peak value ratio (P _max1
/ P _max2 ) is 1.0 to 4.0. It has been found that

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below. The polyester in the present invention is mainly intended for polyethylene terephthalate having ethylene terephthalate as a repeating unit, but if necessary, a small amount of the third component (usually 15 mol% or less, preferably 10 mol% based on the total repeating units) is used. The following, particularly preferably 5 mol% or less) may be a copolymerized polyethylene terephthalate-based copolyester, a matting agent,
It may contain other additives. In particular, when a fine pore-forming agent that forms fine pores or fine grooves on the fiber surface or inside the fiber by the alkali weight reduction treatment is contained, it is contained particularly in the polyester on the thick and thin fiber (A) side described later. In such a case, the shape of the holes or grooves is preferable because various effects such as water absorption, natural silk-like feeling, sharpness, and dry touch can be exhibited.

For example, when the sulfonic acid metal salt represented by the following general formula (I) is contained as the fine pore-forming agent, dry feeling is improved and performance similar to cotton can be obtained.

[0009]

[Chemical 2]

In the formula, M and M'are metals, preferably alkali metals, alkaline earth metals, manganese, cobalt and zinc, and M and M'may be the same or different.
R is a hydrogen atom or an ester-forming functional group, and n is 1
Or 2 is shown.

As such a sulfonic acid metal salt, for example, those described in Japanese Patent Publication No. 61-31231 are preferably used. Specifically, sodium 3-carbomethoxybenzenesulfonate-5-carboxylate sodium, 3-
Mention may be made of sodium hydroxyethoxycarbonylbenzenesulfonate-5 magnesium carboxylic acid 1/2.

The metal sulfonic acid salt may be added to the polyester at any stage before melt spinning of the polyester. For example, it may be added to the raw material of the polyester or blended during the synthesis of the polyester. Good. Also,
If the amount of the above compound added is small, the cotton-like feel of the finally obtained polyester fiber will decrease, while if it is large, problems will easily occur during spinning, so 0.5 to 2.5 based on the polyester weight. % By weight, especially 0.6 to 1.2
A range of weight percent is suitable.

The polyester thick fibers (A), which is one of the components of the composite fluff yarn of the present invention and is made of the above polyester, is in a state of being floated by the heat treatment and bears a stress load even when a load is applied in the stretching direction. In order to contribute only to improvement in bulkiness and to suppress the occurrence of wrinkles, the elongation (ELA) thereof is 80% or more, preferably 100 to 200%.
The elastic recovery rate at 10% elongation (ER
A) must be 50% or less, preferably 40% or less, and the elongation rigidity (EMA) is 5.89 GPa (600).
kg / mm ² ) or less, preferably 1.96 to 4.91 G
It is necessary to have Pa (200 to 500 kg / mm ² ), and the crystallinity (XpA) is 25% or more, preferably 36.
The thermal stress (TSA) at 160 ° C should be 0.44 mN / dtex (50 mg / d
e) must be less than or equal to the boiling water shrinkage (BW
SA) must be 3% or less.

The thick polyester fibers having such characteristics are obtained by, for example, using the above polyester at a temperature of 280 to 3
Melt at 00 ℃, melt and discharge from the spinneret, apply an oil agent to the spun yarn that has been cooled and solidified, and use an interlacing device with three or more air injection holes to achieve a pressure of 0.1 to 0.3MP.
After injecting the air of a to impart interlace, it is passed through a preheating roller and a stretching roller set to a glass transition temperature of polyester or lower (preheating roller take-up speed:
1500-2500 m / min, draw ratio: 1.1-1.
Wind up 5) on a winder once. Then, the obtained drawn yarn (unevenly drawn yarn) is fed at a speed of 500 to 1400 m / min.
Preheating roller heated to 70 to 110 ° C. and 170 to
0.8 ~ after passing through the non-contact heater set to 240 ° C
It can be obtained by heat setting at a draw ratio of 1.1 times (a relaxation heat set is obtained at a draw ratio of 1 or less).

The apparent single fiber fineness of thick and thin fibers (average of fine and thin fibers in the length direction) is not particularly limited, but a range of 1.5 to 5.0 dtex is suitable.
On the other hand, there is no particular limitation on the cross-sectional shape of the single fiber, and a natural cross-sectional appearance that is the object of the present invention can be achieved even with a round cross-section, but a triangular cross-section provides a more dry feeling and a spanize appearance. Is preferable because it can

Next, the polyester stretched fiber (B), which is the other component constituting the composite fluff yarn of the present invention, mainly bears the load in the stretching direction and maintains the shape stability and the stability in the post-processing step. Therefore, the elongation (ELB) must be 40% or less, preferably 30% or less, and the elongation rigidity (EM)
B) is 7.85 GPa (800 kg / mm ² ) or more, preferably 8.83 to 14.7 GPa (900 to 1500)
It should be kg / mm ² ). Also, in order to develop good bulkiness by heat treatment, the boiling water shrinkage (BWSB)
Should be 5% or more, preferably 7 to 20%,
Furthermore, since the polyester thick and thin fibers (A) are not stressed when they are heat set with a pin tenter or the like after being made into a fabric, the deterioration of the texture is suppressed, so that the thermal stress (TSB) at 160 ° C. is 0. .88 mN / dtex (1
00 mg / de) or more, preferably 1.76 mN / dt
It must be ex (200 mg / de) or more.

The stretched polyester fiber having such characteristics may be adjusted, for example, by appropriately adjusting the stretch temperature and the stretch ratio when the unstretched fiber made of the above-mentioned polyester is stretched. For example, the elongation and rigidity may be adjusted by the draw ratio, and the boiling water shrinkage may be adjusted by the heat setting condition at the time of drawing. Especially when high shrinkage is desired, no plate stretching or the like is suitable. The thermal stress can be adjusted by the draw ratio, the heating temperature during the drawing, and the spinning speed of the undrawn fiber. However, if the spinning take-up speed is too high, the thermal stress after stretching may not be increased in some cases, so 2500 m / min or less, preferably 17 m / min.
It is preferable to draw an undrawn fiber having a low spinning speed of 00 m / min or less. As another method of adjusting these characteristics, there is a method of copolymerizing a polyester with a third component,
For example, by copolymerizing an isophthalic acid component, a product having a high shrinkage property can be easily obtained.

The single fiber fineness of the drawn fiber is not particularly limited, but usually a range of 3.5 to 7 dtex, which is higher than the single fiber fineness of the thick and thin fibers, is suitable. On the other hand, although the cross-sectional shape of the single fiber is not particularly limited, a round cross section is usually adopted.

The composite fluff yarn of the present invention is a composite mixture of the above polyester thick and thin fibers (A) and polyester stretched fibers (B). Any method that can be adopted, for example, by passing both of them through an air injection nozzle to be entangled, so that they can be combined and handled as one yarn, may be used. However, in this case, it should be noted that it is necessary to avoid thermally deforming the yarn, for example, false twist crimping, and the wrinkle recovery effect cannot be obtained by such a method. The reason is that firstly, the fibers (A) and (B) are formed by heat treatment, stretching, twisting, etc. in the false twist crimping process.
Of the fine fibers (A) with different physical properties, especially having unstretched parts
The elongation of the steel is reduced, the thermal stress is increased, the elastic recovery rate is improved, and the sluggish elongation property is lost.
The contraction rate of the drawn fiber (B) becomes low and approaches the thick and thin fiber (A), so that the physical properties required for the fibers (A) and (B) of the present invention are deviated. When crimps are applied to the thick and thin fibers (A) appearing on the surface relatively, the yarns entangled with the adjacent yarns or the resistance increases, and the yarns that are misaligned in the woven structure when formed into a fabric such as a woven fabric It is presumed that it is difficult for the position to return to its original position and wrinkles are likely to occur.

In the case of compounding by air injection, the air may be applied in a direction perpendicular to the yarn or along the traveling direction of the yarn. According to the former, a product having relatively excellent gloss is obtained. The latter, on the other hand, gives a product with a relatively soft texture. However, in the latter case, when processing with an excessively large overfeed, a large number of loops are generated, which hinders the recovery of wrinkles. Therefore, it is generally preferable to use 10% at most.

Further, an air feed process may be carried out by providing an overfeed difference between the fibers (A) and (B), but if too much difference is made, a large number of loops are likely to occur, so usually it is almost the same. The overfeed rate of is adopted.

The composite ratio of the thick and thin fibers (A) and the drawn fibers (B) may be appropriately selected and set according to the purpose, but each fiber is present in an amount of at least 20% by weight, preferably A / B. The weight ratio of 45/55 to 70/30 is suitable for achieving the object of the present invention, and the effect of the present invention is more likely to occur particularly when the amount of the thick and thin fibers (A) is larger. 55/45 to 70/3 in the weight ratio of A) / (B)
0 is particularly preferred. Up to now, each of the thick and thin fibers (A) and the drawn fibers (B) has been described by using one yarn as an example.
Of course, two or more yarns may be used, and in short, any number of yarns may be used as long as they satisfy the physical properties required by the present invention. Furthermore, a third yarn which does not satisfy the above physical properties according to the present invention may be added to form a composite. For example, metal-plated fibers or fibers mixed with carbon particles may be combined to impart conductivity, but if the proportion of such fibers becomes too large, the improvement of wrinkle recovery, which is the object of the present invention, is insufficient. Therefore, it is desirable that the combined use ratio is at most 30%.

Next, the spectrograph referred to in the present invention means a Worcester spectrograph developed by Zuelvega of Switzerland, the measurement condition is a normal test, and the measurement speed is 400 m / min. This Worcester spectrograph enables rapid analysis of plaque content, and is particularly useful for knowing the pitch of plaques. For details, see “Mura's Theory and Practice” No. 255 published by The Textile Machinery Society. See page 372.

Examples of spectrographs of the composite fluff of the present invention and the conventional fluff are shown in FIGS. 1 and 2 and will be described in detail with reference to the drawings. Here, FIG. 1 is a spectrograph of the composite plaque obtained in Example 1 of the present invention described later, while FIG. 2 is a spectrograph of a conventional plaque. Comparing FIG. 1 and FIG. 2, it can be seen that there is a characteristic difference in the number of peaks. That is, the composite plaque of the present invention has a plaque cycle of 50 to 150 c.
Since the spots are dispersed so that there are local maximums at two points, a long portion of m and a short portion of 4 to 10 cm, it is more natural than the conventional fluff yarn that has no local maximum in the long period region. It turned out to have a nice spanish appearance.

That is, in the present invention, the period of 4 to 10c is set on the spectrograph obtained by the normal test.
m, preferably 5-8 cm, with a period of 50-150 cm,
Preferably, peak values (P _max1 , P _max2 ) are present in the range of 80 to 120 cm, and the peak value ratio (P _max1 / P _max2 ) is 1.0 to 4.0, preferably 1.
It is important that it is 5 to 2.0. Or had only the peak value is one, or, or a position outside the range of the peak value, and further, the peak value ratio (P _{ma x1} / P
_{When the max2} ) is out of the above range, the random dispersibility of the thick part is lowered and the natural feeling is lowered, or the dry feeling and the spanize appearance are lowered, and the object of the present invention cannot be achieved. .

The period 20c on the spectrograph
Ratio of value P _{20 at} m to peak value P _max1 (P _max1 / P ₂₀ ).
Is in the range of 1.5 to 4.0, preferably 2.0 to 3.0, which is desirable because it further improves the natural feel, dry feel, and appearance of spanize.

If the thickness of the thick portion of the thick fiber (A) is too long, the natural appearance of the fabric tends to be deteriorated. On the other hand, if it is too short, the characteristics as a fluffy yarn are difficult to develop. , 1 to 15 mm, particularly 3 to 10 mm. Further, the Worcester normal U% as a composite yarn is 3.5% or more, preferably 4.5 to
It is preferable to be in the range of 8.0% from the viewpoint that both the feeling of unevenness when touching the fabric and the natural feeling of appearance can be made compatible.

The total fineness of the composite fluff is not particularly limited, but the range of 40 to 250 dtex is suitable.

In order to manufacture a fabric using the polyester composite fluff yarn of the present invention described above, appropriate twisting may be performed as necessary and woven or knit into a desired structure. The obtained cloth is subjected to an alkali weight reduction treatment, if necessary, to obtain an excellent spanize appearance, a natural feeling, and a dry feeling that cannot be exhibited by a conventional woven or knitted product, and a wrinkle-resistant one is obtained. Therefore, it is preferable.

In the present invention, it is not preferable to weave and knit into a complicated structure, since it is intended to have a spanish appearance, a natural feeling, and a dry feeling. Woven knitting with a variable texture, satin weave or the like is preferable. Further, the proportion of the fluff yarn of the present invention in the cloth does not necessarily have to be 100%, but in order to obtain an excellent spanned appearance, natural feeling, dry feeling, and wrinkle recovery property, the higher the ratio, the better. .

[0031]

EXAMPLES The present invention will be described in more detail below with reference to examples. Each measurement item in the examples was measured by the following method.

Elongation (EL) It was measured according to JIS L 1013.

Elastic recovery rate at 10% elongation (ER) According to JIS L 1013, the sample length is 25 cm.
As an initial load, 0.29 mN per 1 dtex (1/30 g per denier) is applied and both ends are gripped and fixed by an air chuck. The measurement condition is 1 at a tensile speed of 20% / min.
After elongation by 0%, the return speed is reduced to 20% / min and returned to the initial load point. The measurement was performed three times and the average value was calculated. Elastic recovery rate at 10% elongation = (elongation at 10% elongation−residual elongation) / 10% elongation at 10% elongation × 100

Elongational rigidity (EM) Measured using a constant-speed elongational tensile tester and a recording device linked thereto. The sample length is 25 cm and the initial load is 1 dt.
Both ends are fixed by an air chuck while being applied with 0.29 mN per ex (1/30 g per denier). The measurement condition is to draw a tangent line to the most inclined curve part from the initial load drawing curve diagram at a pulling speed of 20% / min, and read the stress at 100% elongation. The measurement was performed 5 times and the average value was calculated. Elongation rigidity (EM) = 10 x 100 x 1% Stress at extension x Sample specific gravity / fineness (dtex)

Boiling water shrinkage (BWS) A sample is made by rotating the sample 10 times with a measuring machine (1.125 m per lap). Next, a light load of 0.29 mN per 1 dtex (1/30 g per denier) is applied to measure the length of the ridge. Next, remove the light load, wrap it in gauze to prevent shrinkage, put it in a wire netting basket and soak it in boiling water for 30 minutes, then take it out, remove the moisture with a cloth, dry it naturally, and apply a light load again Measure the length. The boiling water shrinkage was calculated from the following formula, and the measurement was performed at n = 5 to obtain the average value. Shrinkage rate of boiling water (BWS) = (length before immersion−length after natural drying) / length before immersion × 100

Thermal stress (TS) (at 160 ° C.) A thermal stress measuring device and a recording device linked thereto are used for measurement. A 5 cm ring is made from the material using a sampling jig. Next, set the thermal stress measuring device and the recording device at 20 ° C to 300 ° C,
Prepare a state in which a stress range of 0 to 196 mN (0 to 20 g) can be measured, and hang a 5 cm sample of the sample previously sampled on the upper and lower hooks of the thermal stress measuring instrument to 1 dtex.
After applying an initial load of 0.29 mN (1/30 g per denier), the measurement of thermal stress is started. Temperature rising rate is 300 ℃
/ 120 seconds. The measurement is completed when the temperature is raised to 300 ° C. The measurement is performed 3 times. Thermal stress (160 ℃) is 16
The stress at 0 ° C. was read and converted into stress per 1 dtex.

Crystallinity (Xp) The specific gravity of the sample was measured with a density gradient tube (n-pentane: specific gravity 0.683 and carbon tetrachloride: specific gravity 1.599) and calculated from the following formula. Crystallinity (Xp) = d _k (d−d _a ) / d (d _k −d _a ) ×
100 ^{_{However, d k = 1.47g / cm 3}} , d a = 1.331g /
cm ³ , d = Density of sample (g / cm ³ )

[Example 1] Intrinsic viscosity (measured with an ortho-chlorophenol solution at 35 ° C) containing 0.75% by weight of sodium alkylsulfonate having 7 to 20 carbon atoms and having 8 average carbon atoms was 0. 64 polyethylene terephthalate is melted and discharged from the spinneret, the discharged yarn is cooled and solidified, and then an oil agent is applied, and then an interlace is applied by using an air with a pressure of 0.15 MPa with an interlacing device having 3 nozzles. After that, it was drawn at a speed of 2250 m / min, unevenly drawn at a speed of 3030 m / min, and wound as a thick fiber (cross-sectional shape: triangular) having 120 decitex / 36 filaments.

On the other hand, polyethylene terephthalate having an intrinsic viscosity (measured with an orthochlorophenol solution at 35 ° C.) of 0.64 obtained by copolymerizing 10 mol% of isophthalic acid was melted and discharged from the spinneret, and the discharged yarn was cooled and solidified. After applying an oil agent and winding it once at a spinning speed of 1200 m / min, a preheating roller temperature of 85 ° C., a heat set heater (contact type) temperature of 170 ° C., a stretching ratio of 3.1 times, a stretching speed of 1200 m / min.
It was wound as drawn fiber (B) (cross-sectional shape: round) of 55 decitex / 12 filament in minutes. The obtained stretched fiber has an elongation (ELB) of 30% and an elongation rigidity (EM
B) was 11.77 GPa (1200 kg / mm ² ), the boiling water shrinkage (BWSB) was 17%, and the thermal stress (TSB) at 160 ° C. was 4.4 mN / dtex.

The obtained thick and thin fibers were heated at a preheating roller temperature of 110 ° C. and a heat set heater (non-contact type) temperature of 230.
After heat treatment for relaxation at ℃, relaxation rate of 2% and speed of 600 m / min, the yarn is combined with the drawn fiber (B) and mixed and entangled with an air entanglement nozzle to form a composite yarn, which is then wound on a winder to obtain 175.
A composite filament of decitex / 48 filament was obtained. The elongation (ELA) of the thick and thin fibers (A) after the relaxation heat treatment is 120%, and the elastic recovery rate (ERA) at 10% elongation is 30.
%, Elongation rigidity (EMA) is 3.95 GPa (400 k
g / mm ² ), crystallinity (XpA) 40%, boiling water shrinkage (BWSA) 1%, thermal stress at 160 ° C. (TS
A) was 0.18 mN / dtex (20 mg / de).

The obtained fluff yarn is used as a warp yarn and a weft yarn,
The fabric was woven in a habutae, and subjected to scouring, heat setting, alkali weight reduction processing (weight reduction rate 15%), and dyeing according to a conventional method to obtain a plain dyed fabric. The evaluation results are shown in Table 4.

Each of the evaluation items regarding the feeling was a sensory evaluation by five skilled panelists, and those judged to be extremely good by all (good) and those judged by 3 or more to be good (good) ) Those who were judged to be defective by three or more people were ranked as (impossible) in three stages.

As for the evaluation of wrinkle recovery, the fabric was inserted into a device as shown in FIG. 2 in a cylindrical shape, and a weight was placed on the fabric for 3 hours, and then the weight was removed and left for 30 minutes. The degree of wrinkles is scored according to the criteria shown in Table 1.

[0044]

[Table 1]

[Examples 2 and 3, Comparative Examples 1 to 6] Using the thick and thin fibers (A) having the properties shown in Table 2, the range of peak periods on the spectrograph obtained by the normal test in the composite fluff, The same procedure as in Example 1 was carried out except that the peak intensity ratio and U% were set as shown in Table 3. The results are also shown in Table 4.

[0046]

[Table 2]

[Examples 4 to 5 and Comparative Examples 7 to 8] The same procedure as in Example 1 was performed except that the physical properties of the thick and thin fibers (A) and the drawn fibers (B) were as shown in Table 3. . The results are shown in Table 4.
Are shown together with.

[0048]

[Table 3]

[0049]

[Table 4]

[0050]

It has been conventionally known that wrinkle recovery can be improved by twisting the yarn with a strong twist, but the feeling of the twist is very special due to a strong sharpness, a hard touch, and an uneven textured appearance. Not only does it become a woven fabric, but there are problems such as high cost for strong twisting and difficulty in weaving due to torque generation.

According to the composite fluff of the present invention, a woven fabric excellent in wrinkle recovery can be obtained even when untwisted or sweet twist of 600 t / m or less at most, and it is not found in conventional polyester fluff. A fabric with a natural feel, a dry feel to the touch, and a spanize appearance can be obtained.
When the polyester contains a micropore-forming agent, it is possible to obtain a cotton fabric which is excellent in characteristics such as bathochromic property, sweat absorbing property, and comfort when worn, and its industrial value is extremely high. Is large.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of a spectrograph of a polyester composite fluff yarn of the present invention.

FIG. 2 is a perspective view of a wrinkle recovery measuring device used in Examples.

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 4L035 BB31 BB89 BB91 DD07 DD12                       FF10                 4L036 MA05 MA20 MA24 MA39 PA33                       PA42 PA46 UA02 UA06

Claims (7)

[Claims] 1. An elongation (ELA) of 80% or more, an elastic recovery rate (ERA) at 10% elongation of 50% or less, an elongation rigidity (EMA) of 5.89 GPa or less, and a crystallinity (XpA).
Is 25% or more and boiling water shrinkage (BWSA) is 3% or less, 1
Thermal stress (TSA) at 60 ℃ is 0.44mN / dt
Ext or less polyester thick fibers (A) and elongation (EL
B) is 40% or less, elongation rigidity (EMB) is 7.85G
Pa or more, boiling water shrinkage (BWSB) is 5% or more, 160
Thermal stress (TSB) at ℃ 0.88mN / dtex
It is a polyester composite fluff yarn obtained by composite-mixing the above polyester stretched fiber (B), and the yarn has a period of 4 to 1 on a spectrograph obtained by a normal test.
The peak value (P
_max1 and P _max2 ) and their peak value ratio (P _max1
/ P _max2 ) is 1.0 to 4.0. 2. The ratio (P _max1 / P ₂₀ ) of the value P ₂₀ at a period of 20 cm and the peak value P _max1 on the spectrograph obtained by the normal test is 1.5 to 4.0. Polyester composite fluff yarn. 3. A Worcester normal U as a yarn having a thick portion length of 1 to 15 mm of a monofilament having a thickness in the length direction.
% Is 3.5% or more, The polyester composite fluff yarn according to claim 1 or 2. 4. The polyester composite fluff yarn according to claim 1, wherein the composite mixed fiber is applied by an air jet entanglement device, and the air temperature at that time is room temperature. 5. The polyester composite fluff yarn according to any one of claims 1 to 4, wherein the cross-sectional shape of the polyester thick and thin fibers (A) is triangular. 6. The polyester composite fluff yarn according to claim 1, wherein the polyester thick fibers (A) contain a fine pore forming agent. 7. The polyester composite fluff yarn according to claim 1, wherein the fine pore forming agent is a metal salt compound represented by the following general formula. [Chemical 1] [In the formula, M and M ′ are metals, R is a hydrogen atom or an ester-forming functional group, and n is 1 or 2.]