JPH09296325A - Conjugated fiber and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a conjugated fiber, hardly developing elastic crimps with a mechanical stress and having a high developing force of latent crimps when heat-treating the fiber with a small dependence of the latent crimp development on load when developing thereof and provide a method for producing the conjugated fiber. SOLUTION: This conjugated fiber comprises crimps having 8-30% percentage of the crimps and 10-30 crimps/25mm and is capable of developing three dimensional type crimps having 15-35% percentage of the crimps and 20-40 crimps/25 mm number of the crimps by heat treatment thereof at 160 deg.C for 60sec under 0.5mg/d load. The conjugated fiber is obtained by carrying out the melt extrusion of a copolyester containing 1-30mol% ethylene oxide adduct to neopentyl glycol copolymerized as a glycol component as a highly shrinkable component with a polyester comprising ethylene terephthalate recurring unit as a low shrinkable component, performing the conjugated spinning thereof into a side-by- side or an eccentric sheath core type, heat-treating the resultant conjugated fiber at 170-180 deg.C drawing treating temperature at a constant length and imparting crimps having 10-30 crimps/25mm and 8-30% percentage of the crimps thereto with a stuffing type crimping apparatus.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a polyethylene terephthalic acid-based polyester composite fiber (referred to as polyester composite fiber) and a method for producing the same. More specifically, it relates to a latent crimp-developing polyester conjugate fiber and a method for producing the same. Currently, polyethylene terephthalic acid type polyester fiber (referred to as polyester fiber) has excellent mechanical properties, chemical stability, thermal stability, cost merit, recyclability, etc., and is used as a general-purpose polymer for general clothing and industrial materials. Widely used.

[0002] Polyester fibers are used as continuous long fibers in woven fabrics, tire cords, fishing lines, fishing nets, etc. and cut into appropriate lengths to form short fibers. There are cases where it is widely used for such purposes. When used as a fiber aggregate in the field of short fibers, it is used for industrial materials, especially for pad materials, sanitary materials, etc., formation of card web, operability at the time of nonwoven fabric production,
There is a demand for fibers for stretchable non-woven fabric substrates having excellent elongation recovery. In addition, when a spun yarn is made into a stretchable woven fabric, fibers having excellent stretchability are required.

[0003]

2. Description of the Related Art Conventionally, a polyester composite fiber having latent crimp developability has been known as a stretchable nonwoven fabric or knitted fabric. For example, JP-A-3-161519 describes a composite fiber in which a polyethylene terephthalate-based polyester copolymerized with isophthalic acid and a polyester substantially composed of a polyethylene terephthalate unit are combined, and JP-A-3-161519. -150429 has 2,2-
There is a description of a conjugate fiber composed of a copolyester obtained by copolymerizing bis [4- (2-hydroxyethoxy) phenyl] propane and isophthalic acid and a polyester substantially composed of polyethylene terephthalate units.

However, in such a composite fiber,
According to the results of studies by the present inventors, the latent crimp development due to heat treatment has a large load dependency, and the crimp that develops under a high load decreases. That is, in the case of a fiber aggregate, sufficient crimps are not developed due to the restraint inside the fiber aggregates to the fibers when the crimps are developed by the heat treatment, and the crimps for obtaining a satisfactory elongation recovery of the substrate are obtained. Can't give.
Further, crimps (= elastic crimps) due to stress in the fiber axis direction are likely to appear, which is a process that is generally performed when a fiber is made into an aggregate, and when a card web is produced by a card opening machine. Since elastic crimps develop due to mechanical stress, uniform spread on the cylinder of the card spreader is hindered, and the texture of the card web is poor when the spread web is scraped by the fly comb. Become. Further, since the crimping form changes from a mechanical type to a three-dimensional type due to the development of elastic crimps, the tear strength of the web is lowered, the card web is easily torn, and the workability is lowered.

[0005]

DISCLOSURE OF THE INVENTION The inventors of the present invention have eliminated the above-mentioned conventional drawbacks, have excellent latent crimp expression even under restraint, and have little elastic crimp expression due to mechanical stress, The present invention has been completed as a result of intensive research aimed at providing a composite fiber having excellent elongation recovery in the case of a nonwoven fabric, spun yarn or a woven fabric using the same as a fiber assembly.

[0006]

[Chemical formula 1]

Secondly, it has a mechanical crimp having a crimping degree of 8 to 30% and a crimping number of 10 to 30/25 mm, and 0.5.
Three-dimensional crimps developed by heat treatment at 160 ° C. for 60 seconds under mg / d load have a crimp degree of 10 to 40% and a crimp number of 10 to 40.
The composite fiber according to the first aspect, characterized in that

The third one is the composite fiber according to the first or second aspect, which has a cut length of 10 to 150 mm and a fineness of 0.3 to 8 denier.

Fourthly, a copolymerized polyester obtained by copolymerizing 5 to 30 mol% of neopentyl glycol ethylene oxide adduct represented by [Chemical Formula 1] as a glycol component or Neo represented by [Chemical Formula 1] Polyester copolymerized with pentyl glycol ethylene oxide adduct and polyester not containing neopentyl glycol ethylene oxide adduct are mixed, and neopentyl glycol ethylene oxide adduct is added as a glycol component in the whole polyester. The polyester containing 5 to 30 mol% of the product as the high shrinkage component and the polyester having polyethylene terephthalate as the main repeating unit as the low shrinkage component are melted at a temperature 10 to 30 ° C. higher than the melting point of each component, Composite spinning into a buy-side type or an eccentric sheath core type After heat-treating at a processing temperature of 160-190 ° C for a fixed length, a press-type crimping device is used to impart mechanical crimps with a crimp number of 10 to 40/25 mm and a crimp degree of 10 to 40%. The method for producing a conjugate fiber is characterized in that the composite ratio represented by the weight of shrinkage component: the weight of low shrinkage component is 30 to 70:70 to 30.

More specifically, the high-shrinkage component contains 90 mol% or more of terephthalic acid as an acid component and 95-70 mol% of ethylene glycol as a glycol component, and neopentyl glycol represented by [Chemical Formula 1]. Copolymerized polyester obtained by copolymerizing 5 to 30 mol% of ethylene oxide adduct (hereinafter referred to as copolymerized polyester) or [Chemical Formula 1]
By mixing a polyester copolymerized with a neopentylglycol ethylene oxide adduct and a polyester containing no neopentylglycol ethylene oxide adduct, the total content of neopentylglycol ethylene oxide adduct is A polyester mixture containing 5 to 30 mol% of the glycol component of the polyester (hereinafter referred to as a polyester mixture. The above-mentioned copolymerized polyester and polyester mixture are collectively referred to as neopentyl glycol ethylene oxide adduct copolymerized polyester-containing). Polyester terephthalate as a main repeating unit as a low shrinkage component, and a polyester containing no neopentyl glycol ethylene oxide adduct of [Chemical Formula 1] is a side-by-side type or eccentric Shi High shrinkage component weight placed on the core type: composite ratio represented by low shrinkage component weight 30-7
The composite fiber is 0:70 to 30, and the crimp degree is 8 to 3.
It has a mechanical crimp of 0% and the number of crimps is 10 to 30/25 mm, and a three-dimensional crimp developed by heat treatment at 160 ° C. for 30 seconds under a load of 0.5 mg / d has a crimp degree of 10. It is a composite fiber having 40% and a crimp number of 10 to 40/25 mm, and a method for producing the composite fiber.

The copolymerized polyester having a high shrinkage component in the present invention has a copolymerization ratio of neopentyl glycol ethylene oxide adduct represented by [Chemical Formula 1] in the composition of 5 to 30 mol%. The content of the neopentyl glycol ethylene oxide adduct represented by [Chemical Formula 1] in the polyester mixture is 5 to 30 mol% based on the glycol components of all the polyesters mixed. The copolymerized polyester and the polyester mixture have higher amorphousness due to the difference in the molecular structure of the glycol component compared with polyethylene terephthalate, which is the main low-shrinkage component of the present invention, and the heat shrinkage rate when used as a fiber component. A high fiber is obtained. When a fiber is made of a single component, the shrinkage rate of ordinary polyethylene terephthalate fiber at 160 ° C. dry heat is 1 although it depends on the spinning conditions.
5% or less, while the copolyester and the polyester mixture, which are high shrinkage components of the present invention, are 160%.
The shrinkage ratio in dry heat at 0 ° C is as high as 20 to 95%.

The conjugate fiber of the present invention is a high shrinkage component glyco-
The neopentylglycol ethylene oxide adduct represented by [Chemical Formula 1] is used as the component, but if the content is less than 5 mol%, the heat shrinkability is lowered and the latent crimp developability is insufficient. On the other hand, if it exceeds 30 mol%, the drawability is lowered in the drawing process after spinning and the operability is deteriorated.
In addition, the latent crimp developability is increased, the number of crimps after heat treatment is increased, and preferable entanglement between fibers is impeded, resulting in poor stretchability when used as a nonwoven fabric. In addition to tetraphthalic acid, isophthalic acid, etc. can be used as the acid component of the highly shrinkable polyester, but when the copolymerization ratio of tetraphthalic acid is 90 mol% or less, it is elastic due to the load applied to the composite fiber. The content of tetraphthalic acid increases because the appearance of crimps becomes large, and crimps develop due to the opening process, carding process, etc. before the latent crimps are developed by heat treatment and the card web has a poor texture. The ratio is 90 mol% or more, preferably 95 mol% or more, and most preferably 100 mol%.

In the present invention, the composite ratio of the high shrinkage component neopentylglycol ethylene oxide adduct copolymerized polyester-containing polyester and the low shrinkage component neopentylglycol ethylene oxide adduct-free polyester is side-by-side. 50:50 for the side type
Can be changed within a range not to impair the intended effects of the present invention, 30:70 to 70:30, preferably 40:
60 to 40:60 is preferable. Also in the case of the eccentric sheath core type, the composite ratio of the core component of the neopentyl glycol ethylene oxide adduct copolyester-containing polyester to the sheath component not containing neopentyl glycol ethylene oxide adduct is It can be changed around 50:50 within a range that does not impair the intended effects of the present invention.
0:70 to 70:30, preferably 40:60 to 40:
60 is good.

It is preferable that the cross section of the fiber has a modified cross section or a hollow cross section so that when it is made into an aggregate, functions such as bulkiness, texture, and water movement due to capillary phenomenon are imparted. Further, in order to impart antistatic property, flame retardant property, antibacterial property, deodorant property, easy-feeling property, etc., a surface modifier, an additive and a third component are optionally blended within a range that does not impair the intended effects of the present invention. be able to.

The conjugate fiber of the present invention is melted at a temperature higher than the melting point by 10 to 30 ° C. by a well-known polyester two-component spinning device, and is joined immediately before the orifice to be composite-spun. The intrinsic viscosity of the polyester containing the high-shrinkage component neopentylglycol ethylene oxide addition copolymerized polyester and the low-shrinkage component neopentylglycol ethylene oxide adduct is:
From the stability of polymer discharge from the spinning nozzle during melt spinning, it is preferable to set so that the difference in melt viscosity during melting is 500 poise or less at the same temperature which is 10 to 30 ° C. higher than the melting point. The melt viscosity difference is more preferably 100 poise or less, and further preferably 10 poise or less. The melt spun yarn may be cooled by either uniform cooling or asymmetric cooling as long as the effects of the present invention are not impaired. After cooling and drawing, the undrawn yarn thus obtained is subjected to two-stage drawing or three-stage drawing. For example, the first stage has a tow temperature of 50 ° C. or more and 100 ° C. or less and a breaking draw ratio (MDR) of 0.70.
~ 0.75 times. The second stage is MDR 0.80-0.
Perform at 85 times. Further, in order to adjust the physical properties to the intended use, the stretching in the third step is 0.9 to 0.95 times the MDR. After the steps of stretching, oiling, and mechanical crimping, the product is cut to a predetermined cut length (10 to 150 mm) and manufactured, but the two-stage stretching or three-stage stretching is a constant length heat treatment or restriction at a processing temperature of 160 to 190 degrees. It is necessary to perform shrinkage heat treatment. The composite fiber of the present invention obtained by the combination of the high-shrinkage component neopentylglycol ethylene oxide addition copolymerized polyester-containing polyester and the low-shrinkage component neopentylglycol ethylene oxide adduct-free polyester is When the latent crimp developability is high and the heat treatment by the constant length during stretching is not performed or the constant length heat treatment is performed at a temperature of 160 ° C. or less, the crimp degree of the latent crimp developed during the heat treatment becomes too large. In that case, preferable entanglement between fibers is hindered, and the stretchability of the aggregate becomes poor. When the temperature of the constant length heat treatment is 190 ° C. or higher, the latent crimp developability is lowered and the fiber assembly is inferior in elongation recovery. As a method of heat treatment of a constant length, a method of performing heat treatment at 160 to 190 degrees with a heat source such as a hot plate or a pressurized steam between rollers having a constant rotation speed ratio, and a constant rotation speed ratio. Hot roller top 160 ~
There is a method such as performing heat treatment at 190 ° C.

Further, in the conjugate fiber of the present invention, the raw cotton before heat treatment in the mechanical crimping step has a mechanical crimp form, and the crimping degree (CI) is 8% or more, more preferably 10% or more, 30
%, The number of crimps (CN) is required to be 10 pieces / 25 mm or more, more preferably 10 pieces / 25 mm or more and 30 pieces / 25 mm or less. When the crimping degree is less than 8% and the number of crimps is less than 10 pieces / 25 mm, uniform opening is not performed during opening processing when forming short fibers into an aggregate, and unevenness occurs in the opening web. The crimp degree exceeds 30% and the number of crimps is 30.
If the number exceeds 25 mm, the texture of the card web after card opening will deteriorate. The crimp degree is less than 8%, the number of crimps is 10 /
If it is less than an inch, the web is easily broken and it becomes difficult to handle the web.

The composite fiber of the present invention has a specific resistance value (log Ω) of 9 or less, preferably 8 or less, due to the use of an antistatic agent or the like. If the specific resistance value exceeds 10, undesirably, problems such as static electricity winding around the card machine and uneven web density occur during the fiber-opening process.

The fineness of the polyester fiber of the present invention is 0.3 denier or more, 8 from the texture of the product and the card openability.
It is preferably not more than denier, preferably 0.5.
Denier or more and 5 denier or less, more preferably 1 denier or more and 4 denier or less. If it is less than 0.3 denier or exceeds 8 denier, the texture of the product and the openability of the card will be deteriorated, and it cannot be used in the present invention.

The cut length of the fiber for wadding of the fiber of the present invention is not particularly limited, but it is possible to open the fiber with a known ordinary card and easily maintain the binding property, and it is preferably 10 to 150 mm, preferably 25.
１２０120 mm. If the cut length is other than this, the card opening property is poor and there is a drawback that the quality of the yarn is deteriorated.

The conjugate fiber of the present invention has a crimp occurrence number (CN) of 1 after heat treatment at 160 ° C. under a load of 0.5 mg / d.
It is necessary that 0 to 40 pieces / 25 mm and crimping degree (CI) be 10 to 35%. 0.5 mg / d at 160 ° C
If the number of crimp occurrences after heat treatment under 10 load is less than 10 pieces / 25 mm, the entanglement of fibers in the nonwoven fabric is insufficient and the binding force inhibits latent crimp after heat treatment, resulting in satisfactory elongation recovery. I can't get it. On the other hand, if the number exceeds 40/25 mm, the crimp is too fine and the value as crimped fiber is reduced. When the crimping degree (CI) is less than 10% or more than 40%, the width of expansion and shrinkage due to the crimping is small, and it is too large, and the elongation recovery is low. The preferred crimp occurrence number (CN) is 20 to 50 pieces / 25 mm, and the crimp degree (CI) is 1.
5 to 35%.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention are shown below.
A copolymerized polyester using neopentyl glycol ethylene oxide adduct represented by [Chemical Formula 1] as a glycol component in an amount of 30 mol%, ethylene glycol in an amount of 70 mol%, and terephthalic acid as an acid component is a highly shrinkable component. Using polyethylene terephthalate composed of ethylene terephthalate repeating units as the low shrinkage component, spinning was performed at a spinneret temperature of 285 ° C., a single hole discharge rate of 1.2 g / min, and a spinning speed of 600 m / min. First stage stretching temperature 80 ° C, first stage stretching ratio 4.5 times (MDR x 0.7
5), followed by a second-stage drawing temperature of 175 ° C., a second-stage draw ratio of 4.8 times (MDR × 0.80), a fixed length heat treatment, and a filament crimping machine mechanical crimping machine. It is given and cut with an Eastman cutter to shorten the fiber, fineness 2.5 denier, fiber length 51 mm, composite ratio 5
The composite fiber of the present invention is obtained as a 0:50 side-by-side type fiber.

[0022]

Examples are shown below. The methods for measuring the characteristic values and the like in the examples and the text are as follows. (1) Intrinsic viscosity Using para-chlorophenol solvent, 2
Measured by a conventional method at 5 ° C (2) Fineness Measured by the method of JIS-L1015-7-5 (3) Number of crimps (CN) Measured by the method of JIS-L1015-7-12 (4) Crimpness ( CI) Measured by the method of JIS-L1015-7-12 (5) Measurement of specific resistance value, conductivity of 2g of sample fiber left in standard condition (temperature 20 ± 2 ° C, relative humidity 65 ± 2%) for 4 hours or more The electric resistance value (Ω) was measured 2 minutes after the fiber was put on the sample table with a measuring machine and the heavy-duty electrode was placed on the sample table. (6) 50% elongation recovery rate A test piece of 50 mm x 200 mm was attached to a constant speed extension type tensile tester with a self-recording device as a gripping width, and was attached at 100 mm in the fiber orientation direction by a card, and a pulling speed of 500 / min. With 50mm pull back to the original position at the same speed,
After drawing a load-elongation curve and extending 50 mm, the elongation (a) at the returning position is used to express the 50% elongation recovery rate by the following formula. 50% elongation recovery rate = (50-a) / 50) × 100 (7) Unit weight test piece cut into 20 cm × 20 cm for 24 hours or more, standard condition (temperature 20 ± 2 ° C., relative temperature 65 ± 2% RH) Then, the sample is weighed with a weight balance and the weight per unit area (1 cm ² ) (g / cm ² ) is shown. (8) Thickness DIAL GAUGE (compression plate φ30 made by OZAKI
mm, 80 g) and measure the thickness of the sample at arbitrary 5 points, and take the average value. (9) Measurement of the number of crimp occurrences under load, and using a frame with a stainless steel clip, clamp the upper end of the sample fiber in the clip and hang it. Then, a load of 0.5 mg per 1 d of fineness is applied to the lower end of the sample, and the sample is placed in a circulating heat dryer heated to 160 ° C. for 60 seconds, and then the crimp number (C
N) and crimping degree (CI) are defined in JIS-L1015-7
It is measured by the method of -12. (10) Observe the occurrence of elastic crimps, hold the upper end of the sample fiber between the clips using a stand with a stainless steel clip, and hang it. And 3.0g per 1d of fineness at the bottom of the sample
Apply a load of and leave for 1 minute. Then, the change in crimp form of the sample before and after the unloading and the load is visually compared. (11) Evaluation of card web texture, sample raw cotton was set on a single doffer type card machine manufactured by Ikegami Seisakusho, and cylinder (634 mm) rotation speed 270 rpm, doffer
(634 mm) A cardweap sample was prepared under the conditions of a doffing speed of 40 m / min at a rotation speed of 14.1 rpm, the cardweap was spread on a black paper, and the texture was visually evaluated.

[0023]

Examples 1 to 3 and Comparative Examples 1 and 2 (Inventive conjugate fiber) A stainless steel autoclave was used as a highly shrinkable copolymerized polyester, and 100 mol% of terephthalphthalic acid was used as a dibasic acid component. 70 mol% of ethylene glycol and 30 mol% of neopentyl glycol ethylene oxide adduct represented by [Chemical Formula 1] were used as a glycol component, and 0.05 mol% of antimony trioxide (as an acid component) was used as a catalyst. Was used for polycondensation by the direct esterification method. This copolymer had an intrinsic viscosity of 0.72 [highly shrinkable component of Example 1]. Similarly, 50 mol% of ethylene glycol as a glycol component and neopentylglycol represented by [Chemical Formula 1] is used.
50 mol% of ethylene oxide adduct [highly shrinkable component of Comparative Example 1], 80 mol% of ethylene glycol and 20 mol% of neopentyl glycol ethylene oxide adduct represented by [Chemical Formula 1] [Example 2] High shrinkage component of
95 mol% of ethylene glycol, 5 mol% of neopentyl glycol ethylene oxide adduct represented by [Chemical formula 1] [highly shrinkable component of Example 3], and 99 mol% of ethylene glycol [Chemical formula 1] A copolymerized polyester having 1 mol% of neopentylglycol ethylene oxide adduct represented by the formula [Highly shrinkable component of Comparative Example 2] was obtained. As the low shrinkage component polyester, the intrinsic viscosity (I
V) = 0.63 polyester resin pellets (RD-
730: manufactured by Toyobo Co., Ltd.) and a composite ratio at a nozzle spinneret temperature of 285 ° C. from a round-section spinneret hole, a high-shrinkage component: low-shrinkage component = 50: 50 and a discharge rate of 1.2 g / min. Was extruded at a speed of 600 m / min to obtain a side-by-side type undrawn yarn. Further, a composite ratio using the high shrinkage component of [Example 1], high shrinkage component: low shrinkage component = 20: 80 [Comparative Example 3], 30:70 [Example 4], 70:30 [Example 5], 80:20 [Comparative Example 4] 1.2 g / min, extrusion rate 600 at hole discharge speed
A side-by-side type undrawn yarn was obtained at a speed of m / min.

As the dibasic acid component of the high shrinkage component, 95 mol% of terephthalphthalic acid and 5 mol% of isophthalic acid,
70 mol% of ethylene glycol as a glycol component
And 30 mol% of neopentyl glycol ethylene oxide adduct represented by [Chemical Formula 1] [Example 6] 90 mol% of terephthalphthalic acid, 10 mol% of isophthalic acid and glyco as dibasic acid components -70% by mole of ethylene glycol and 30% by mole of neopentylglycol ethylene oxide adduct as a phenol component [Example 7] 85 mol% of terephthalphthalic acid and isophthalic acid as dibasic acid components Polymerization using 15 mol%, 70 mol% of ethylene glycol as a glycol component and 30 mol% of neopentyl glycol ethylene oxide adduct represented by [Chemical Formula 1] [Comparative Example 5] was similarly polymerized. Extrude at a hole discharge rate of 1.2 g / min 60
A side-by-side type undrawn yarn was obtained at a speed of 0 m / min.

The composite ratio spinneret was changed to an eccentric sheath core type [Example 1], and spinning was carried out at a composite ratio of 50:50 using the high shrinkage component and low shrinkage component, and a hole of 1.2 g / min was formed. An extruded sheet was wound at a discharge speed of 600 m / min to obtain a sheath-core type undrawn yarn. [Example 8] Also, using the high shrinkage component of [Comparative Example 1], the high shrinkage component of [Comparative Example 1]: Polyester resin pellets (RD-73)
0: manufactured by Toyobo) with a mixing ratio of 10: 7 [high-shrinkage component of Example 9], 1: 9 [high-shrinkage component of Example 10], 1:
49 [highly shrinkable component of Comparative Example 9] to obtain a polyester mixture, each having a high shrinkage component and a composite ratio of 50:
Spinning was performed at 50, extrusion was performed at a hole discharge rate of 1.2 g / min, and winding was performed at a speed of 600 m / min to obtain a side-by-side type undrawn yarn.

These unstretched yarns were stretched at a first stage draw ratio of 0.75 times MDR and a first stage draw temperature of 80 ° C., and a second stage draw ratio was set to 0. 80 times,
The second stage heat treatment is performed at a constant length heat treatment temperature of 175 ° C., and after a mechanical crimp is applied by an indentation type crimper, a fiber length of 51 mm is cut with an Eastman cutter to obtain a fineness of 2.5 d and a fiber length of 51 mm. Raw cotton of each Example and Comparative Example was obtained. Also, using the undrawn yarn of [Example 1] as the fiber in which only the second stage constant length heat treatment temperature was changed to 155 ° C [Comparative Example 7] and the fiber changed to 195 ° C [Comparative Example 8], and the mechanical winding [Comparative Example 9] and [Comparative Example 10] were prepared by changing the stuffing box pressure under the condition of shrinkage. [Table 1] shows the measurement results of the number of crimp occurrences and the occurrence of elastic crimps under load.

[0027]

[Table 1]

[0028]

[Examples 1 to 10],

[Comparative Examples 1 and 2] (Stretchable non-woven fabric using the composite fiber of the present invention) Raw cotton is card-opened to form a card web, which is laminated with a cross layer and the fiber is laid with a needle punch. Entangle, 160
Heat treatment for 60 seconds at ℃, basis weight 97-100g / m
^2. A stretchable nonwoven fabric having a thickness of 0.9 to 0.95 was prepared.
Table 1 shows the results of evaluation of the card web formation and the 50% elongation recovery in the fiber axis direction of the non-woven fabric.

[Table 1] shows that [Examples 1 to 10] are composite fibers that do not develop elastic crimps due to stress and develop the crimps necessary for a stretchable nonwoven fabric during heat treatment under load. It was excellent in card web formation and elongation recovery rate.

[0030]

EFFECT OF THE INVENTION The conjugate fiber of the present invention is a fiber in which the occurrence of elastic crimp due to mechanical stress is small, the latent crimp developing power at the time of heat treatment is high, and the load dependency upon latent latent crimp expression is small. It is a composite fiber that is suitable for non-woven fabric applications with good stretchability by utilizing shrinkage. Even when used as a spun yarn, it is possible to impart preferable stretchability to a woven fabric. Further, it is also useful as a cotton pad or a cushioning material.

Claims (4)

[Claims] 1. A side composed of a high shrinkage component and a low shrinkage component, which develops crimp due to a difference in shrinkage between the two components during heat treatment.
In the bi-side type or eccentric sheath core type polyester composite fiber, a copolymer of neopentyl glycol ethylene oxide adduct represented by [Chemical Formula 1] as a glycol component in an amount of 5 to 30 mol% Polyester or neopentylglycol represented by [Chemical Formula 1]
A polyester obtained by copolymerizing a ruthenium oxide adduct and a polyester not containing a neopentylglycol ethylene oxide adduct are mixed, and the neopentylglycol ethylene oxide adduct is 5% as a glycol component in the total polyester. -30% by mole of polyester is used as the high shrinkage component, and the composite ratio represented by high shrinkage component weight: low shrinkage component weight is 30 to 70:70 to 30.
Is a composite fiber. [Chemical formula 1] 2. A crimp degree of 8 to 30% and a crimp number of 10 to 3
Three-dimensional crimps having a mechanical crimp of 0/25 mm and developed by heat treatment at 160 ° C. × 60 seconds under a load of 0.5 mg / d, the crimping degree is 10 to 40%, and the crimping number is 10 to 10. 40 pieces / 25
The composite fiber according to claim 1, wherein the composite fiber is mm. 3. The composite fiber according to claim 1, which has a cut length of 10 to 150 mm and a fineness of 0.3 to 8 denier. 4. A copolymerized polyester obtained by copolymerizing neopentylglycol ethylene oxide adduct represented by [Chemical Formula 1] as a glycol component in an amount of 5 to 30 mol%, or neopentylglycol represented by [Chemical Formula 1]. Polyester copolymerized with ethylene oxide adduct,
A polyester containing no neopentyl glycol ethylene oxide adduct as a glycol component in the total polyester and containing 5 to 30 mol% of neopentyl glycol ethylene oxide adduct as a highly shrinkable component , Polyethylene terephthalate as a low shrinkage component is melted at a temperature 10 to 30 ° C. higher than the melting point of each component as a low shrinkage component, and side-by-side type or eccentric sheath core type composite spinning is performed. Then, after performing a constant length heat treatment at a treatment temperature of 160 to 190 ° C. in the stretching step, the number of crimps is set to 10 by a press type crimp imparting device.
Mechanical crimps of 40/25 mm and a crimping degree of 10 to 40% are applied, and a composite ratio represented by high shrinkage component weight: low shrinkage component weight is 30 to 70:70 to 30 Fiber manufacturing method.