JPH08209451A - Polyester conjugated fiber - Google Patents

Abstract

PURPOSE: To obtain woven, knitted or nonwoven fabrics which are suitably used as a base cloth and a wadding for medical and hygienic purposes because of their excellent stretchability and elastic recovery using latently crimpable conjugated fibers. CONSTITUTION: Polyester and copolyester prepared by copolymerizing a compound having a norbornene skeleton represented by formulas I and II (X1 , X2 , X3 and X4 are each CH2 OH or a COOR or a COOR<1> where R and R<1> are each a lower alkyl; (m) is 0 or 1) with a polyethylene terephthalate or a polybutylene terephthalate are conjugate-spun into a yarn of an eccentric side-by-side cross section and drawn. Then, the drawn yarn is mechanically crimped at a rate of 12 or less crimps/25mm, and cut to form short-cut fibers of the conjugated yarn. The short-cut fibers are curded, spun and the spun yarns are woven or knitted, or curd webs are interlaced by water flow to give nonwoven fabric. Then, the woven, knitted or nonwoven fabric is subjected to crimp-developing treatment to reveal spiral crimps of 40 or more crimps/25mm at 130 deg.C.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyester fiber having excellent stretchability and suitable for obtaining a non-woven fabric having a small bulkiness. More specifically, it relates to a composite fiber having a latent crimping ability suitable for obtaining a stretchable non-woven fabric having a good fitting property for a poultice or padding by mixing with a normal polyester fiber or the like.

[0002]

2. Description of the Related Art Stretchable woven fabrics, knitted fabrics, non-woven fabrics, etc. are very useful as base fabrics for clothing represented by sports clothing and medical hygiene agents such as padding and poultices. Has been used in large amounts in. For these applications, fibers that are excellent in stretchability and elastic recovery from the demands of functionality and fitting properties and that can easily reduce the bulkiness when formed into woven fabrics, knitted fabrics, nonwoven fabrics, etc. are required. ing.

It has been proposed to use false twisted textured yarns, conjugate type filaments, latently crimped conjugate fibers and the like in order to impart stretchability and elastic recovery to a nonwoven fabric. ing. However, these have some drawbacks. That is, when a false twisted yarn is used, it is difficult to obtain a non-woven fabric having poor card passage properties and uniformity due to strong crimping. Further, when a conjugate type filament is used, since the fibers are oriented in one direction, the directionality of stretchability is remarkable, and it may be difficult to put into practical use depending on the field of use.

Further, when the latently crimpable conjugate fiber is used, it is good in terms of uniformity, elastic recovery and directionality, but in the conventional latently crimpable filament, the fiber physical properties after the crimping heat treatment are excellent. Fabrics that are greatly degraded or cured,
The texture and flexibility of the non-woven fabric were sometimes greatly impaired. The reason for this is that the conventional conjugate fiber has a small shrinkage stress even if it has a large shrinkage ratio, so that almost no crimp is exhibited by tensioning such as a fabric or a non-woven fabric, and the stretchability and elastic recovery property are very high. One of the reasons is that you can only get scarce things. Further, since many conventional spiral crimps have already been developed in the conventional conjugate fiber before the crimp development treatment (heat treatment), the conjugate fiber becomes lumps or spots during cutting and carding. And it can be cited as the cause of many troubles.

In order to suppress the development of crimps before the crimp development treatment, it has been proposed and practiced to impart heat history to the fibers together with the shrink treatment during the fiber production. However, according to this method, the shrinkage ability of the fiber is reduced and the expression of the above-mentioned crimps is suppressed, but the expression of the latent crimps due to the subsequent crimp expression treatment is significantly reduced, which is required. It is very difficult to obtain a non-woven fabric having excellent stretchability and elastic recovery.

[0006] Thus, when the crimp developability after crimp revealing treatment is emphasized, the processability and productivity of cutting, carding and the like are lowered, and the processability and productivity are reduced. When the importance is placed on it, the crimp developability after the crimp manifestation treatment decreases, and the latent crimp performance that simultaneously satisfies both processability, productivity and crimp developability after the crimp develop treatment. The fact is that a composite fiber having the above has not been proposed yet.

[0007]

SUMMARY OF THE INVENTION The object of the present invention is to satisfy both the processability, the elimination of the deterioration of productivity and the expression of crimps after the crimp expression treatment, and the elasticity and elasticity. It is an object of the present invention to provide a polyester composite fiber having latent crimping performance capable of obtaining a fabric and a non-woven fabric having excellent recoverability.

[0008]

According to the present invention, the above object is to provide a polyethylene terephthalate-based polyester or a polybutylene terephthalate-based polyester copolymerized with a compound having a norbornane skeleton, and a polyester. Are eccentrically joined, and the number of latent crimps at 130 ° C. is 40/25 mm or more, and the number of crimps before crimping is 13/25 mm or less. It is achieved by providing a polyester composite fiber.

In the present invention, the "compound having a norbornane skeleton" is a compound represented by the following formula I or formula II.

[0010]

Embedded image (In the formula, X ₁ and X ₂ are respectively CH ₂ OH or C
Represents OOR, R represents a lower alkyl group, and m represents 0 or 1. )

[0011]

[Chemical 4] (In the formula, X ₃ and X ₄ are respectively CH ₂ OH or C
Represents OOR ', and R'represents a lower alkyl group. )

Specific examples of the compound represented by the formula I include:
Norbornane-2,3-dimethanol, norbornane-
2,3-Dicarboxylic acid and its diester, perhydro-1,4: 5,8-dimethanonaphthalene-2,3-dimethanol, perhydro-1,4: 5,8-dimethanonaphthalene- Examples thereof include 2,3-dicarboxylic acid and its diester, and the stereostructure of these compounds may be either cis isomer or trans isomer, or a mixture thereof.
In addition, the alicyclic structure part thereof may be an endo-form or an exo-form. It may be a mixture thereof.

Specific examples of the compound represented by the formula II include tricyclodecane dimethanol, tricyclodecane dicarboxylic acid and diesters thereof, and a mixture thereof may be used. Further, the alicyclic structure part thereof may be an endo-form, an exo-form, or a mixture thereof. In addition, R and R ′ in the formulas I and II are
The lower alkyl group refers to an alkyl group having 1 to 4 carbon atoms.

The copolymerization amount of these compounds is 5 to 15 mol%, preferably 8 to 13 mol% of the dicarboxylic acid component constituting the polyethylene terephthalate polyester or polybutylene terephthalate polyester. . When the copolymerization amount is less than 5 mol%, the decrease in the crystallinity of the polyester and the increase in the shrinkage ratio are insufficient, and it is not possible to obtain a conjugate fiber having the desired latent crimping performance. On the other hand, when the copolymerization amount exceeds 15 mol%,
The polymerizability of the polyester is lowered, and a crystalline polyester cannot be obtained. Even if it is obtained, the melting point of the polyester is lowered and it becomes impractical in terms of heat resistance and the like.

As the amount of copolymerization of the compound increases, the crystallinity and melting point of the polyester decrease, but the shrinkage rate of the composite fiber containing the polyester as a component increases. It may be changed within the copolymerization amount range.

Polyethylene terephthalate type polyester or polybutylene terephthalate type polyester obtained by copolymerizing these compounds (hereinafter referred to as "A polymer").
May be referred to as)) containing 70 mol% or more of polyethylene terephthalate or polybutylene terephthalate, or a unit of polyethylene terephthalate or polybutylene terephthalate obtained by copolymerizing the compound. The remaining copolymerization component may be isophthalic acid, phthalic acid, naphthalenedicarboxylic acid, biphenyldicarboxylic acid, 4,4′-diphenyletherdicarboxylic acid, 4,4′-diphenylmethanedicarboxylic acid, 4, 4'-diphenylsulfone dicarboxylic acid,
4,4'-diphenylisopropylidenedicarboxylic acid,
1,2-Diphenoxyethane-4 ′, 4 ″ -dicarboxylic acid, anthracene dicarboxylic acid, 2,5-pyridinedicarboxylic acid, diphenylketone dicarboxylic acid, aromatic dicarboxylic acid such as sodium sulfoisophthalate; malonic acid, succinic acid , Adipic acid, azelaic acid, sebacic acid and other aliphatic dicarboxylic acids; decalin dicarboxylic acid, cyclohexanedicarboxylic acid and other alicyclic dicarboxylic acids; β-
Hydroxycarboxylic acids such as hydroxyethoxybenzoic acid, p-oxybenzoic acid, hydroxypropionic acid and hydroxyacrylic acid; or ester-forming derivatives thereof; aliphatic lactones such as ε-caprolactone; trimethylene glycol, tetramethylene glycol -, Hexamethylene glycol, neopentyl glycol, diethylene glycol, polyethylene glycol, and other aliphatic diols; hydroquinone, catechol, naphthalene diol
, Resorcin, bisphenol A, bisphenol A
Aromatic diol such as ethylene oxide adduct of bisphenol S, bisphenol S, ethylene oxide adduct of bisphenol S; alicyclic diol such as cyclohexane dimethanol
Can be mentioned. These copolymer components are 1
Only one species may be used, or two or more species may be used.

Further, the polyethylene terephthalate-based polyester or the polybutylene terephthalate-based polyester contains trimellitic acid, trimesic acid, pyromellitic acid, and trimellitic acid within a range in which the polyester is substantially linear. Polyvalent carboxylic acids such as carballylic acid; glycerin, trimethylolethane, trimethylolpropane,
A polyvalent alcohol such as pentaerythritol may be contained.

The intrinsic viscosity [η] _A of the A polymer measured in a phenol / tetrachloroethane mixed solvent (weight ratio 1/1) is preferably in the range of 0.55 to 0.80. When the intrinsic viscosity is less than 0.55, the strength of the composite fiber is remarkably deteriorated. On the other hand, when the intrinsic viscosity exceeds 0.80, the texture of the nonwoven fabric obtained from the composite fiber becomes hard, which is not practical.

The A polymer can be produced by any method. For example, terephthalic acid may be directly esterified with ethylene glycol, tetramethylene glycol or 1,4-butanediol, or a lower alkyl ester of terephthalic acid such as dimethyl terephthalate may be reacted with ethylene glycol or tetraglycol. The first-step reaction in which a glycol ester of terephthalic acid and / or its low polymer is formed by transesterification with methylene glycol, and a polycondensation reaction by heating the reaction product under reduced pressure. In the production by the second step reaction, the compound having a norbornane skeleton may be copolymerized in a desired amount.

The other polyester constituting the conjugate fiber of the present invention (hereinafter sometimes referred to as B polymer) is a polyester which is not copolymerized with a compound having a norbornane skeleton, and its kind is not particularly limited. , Polyethylene terephthalate, polybutylene terephthalate, or those containing 80 mol% or more of these units. A polyester obtained by copolymerizing a copolymer component other than the above-mentioned compound having a norbornane skeleton may be used.

The intrinsic viscosity [η] _B of the B polymer measured in a phenol / tetrachloroethane mixed solvent (weight ratio 1/1) is in the range of 0.50 to 0.75. It is preferable in the conjugation with the A polymer.

The difference in intrinsic viscosity between the A polymer and the B polymer is [η] _A > in consideration of the spinnability of the composite fiber.
[Η] _B is preferable, and [η] _A −
It is preferable that [η] _B = 0.005 to 0.06. When the intrinsic viscosity [η] _{A of the A} polymer is the same as or smaller than the intrinsic viscosity [η] _{B of the} B polymer, crimps appear more than necessary after stretching, and the latent crimpability becomes poor. There are cases. Further, if the difference is too large, skewing may occur during spinning, and stains on the spinneret, yarn breakage, and fluff may occur, which is not preferable.

The conjugate fiber of the present invention comprises an A polymer and a B polymer which are eccentrically joined by a composite spinning process, and develops a spiral crimp by a relaxation heat treatment, which is a crimp expressing heat treatment. A composite fiber having latent crimping ability. The composite form is not particularly limited, but is an eccentric core-sheath type,
The side-by-side type is used, and the side-by-side type is preferable in consideration of the crimp developability. Further, the cross section of the fiber is not particularly limited, and may be any of a round cross section, a tri-octagon cross section, a flat cross section, a T-shaped cross section, a U-shaped cross section, and the like. Further, these may be hollow fibers or solid fibers.

In order to produce such eccentrically joined composite fibers, conventionally known spinning and drawing methods can be used as they are.

A polymer constituting the conjugate fiber of the present invention
Has a specific molecular structure that it is easily oriented by using a compound having a norbornane skeleton as a copolymerization component, but is difficult to crystallize. Therefore, the single fiber composed of the A polymer has a large shrinkage ratio. Nevertheless, it also has the same large contraction stress as polyethylene terephthalate fiber. By using the A polymer having such a performance as one component of the composite fiber, it is possible to obtain a composite fiber having a spiral crimp developing ability of 40 pieces / 25 mm or more when heat-treated at 130 ° C.

The composite fiber of the present invention has a thickness of 130 as described above.
The number of crimps after spinning / stretching, that is, the number of crimps before the crimp development treatment is 13/2 even though it has a spiral crimp development ability of 40/25 mm or more when heat treated at ℃.
It is 5 mm or less, particularly 10 pieces / 25 mm or less, and there is no need to perform heat treatment for suppressing the number of crimps, which has been conventionally performed, and therefore, the occurrence of crimps after the crimping treatment is reduced. Therefore, a non-woven fabric having excellent elastic recovery and stretchability can be obtained. The conjugate fiber of the present invention has a very small number of crimps before the crimp expression treatment,
The above heat treatment may be performed in order to bring the number of crimps closer to zero.

In order for such a composite fiber to have such crimping performance, the composite ratio (weight ratio) of A polymer and B polymer is A / B = 2/1 to 2/3, preferably 4 /. 3-1
It is / 1. When it is out of this range, the above-mentioned specific crimping performance is hard to be exhibited. Further, the average fineness of the composite fiber can be appropriately set depending on the application. For example, when obtaining a non-woven fabric such as a poultice, the average fineness is 1.5 to
It is preferably in the range of 2.5 denier. If the average fineness exceeds 2.5 denier, the texture will be poor when made into a non-woven fabric, while if it is less than 1.5 denier, the card will not pass easily when made into a web. The nep spots on the web are large.

When a nonwoven fabric is prepared from the composite fiber thus obtained, it is subjected to a cutting process and a card process, but the composite fiber of the present invention has 13 crimps after spinning and drawing.
Since it is very small as 25 / mm or less, neps and unopened portions are unlikely to occur in such a step, and a non-woven fabric having a high degree of uniformity can be obtained.

The composite fiber of the present invention may be subjected to a carding process after spinning and drawing, but in order to further improve the card passing property, mechanical crimping in the range of 8 to 18 fibers / 25 mm is required. It may be applied. The method of applying the mechanical crimp may be carried out by an ordinary method using a press crimping machine or the like.

The composite fiber of the present invention may contain modifiers such as a matting agent, a gloss improving agent, an antistatic agent, a flame retardant and a softening / smoothing agent.

Although the conjugate fiber of the present invention has a high latent crimping capacity, it has a very small number of crimps in the fiber after spinning and drawing, so that nep or unopened portion is generated in the carding step. However, a non-woven fabric having a high number of crimps and a high elasticity and high elastic recovery property of 40 crimps / 25 mm or more can be obtained by heat-treating the non-woven fabric. The heat treatment temperature is preferably 120 ° C. or higher, and the higher the heat treatment temperature, the greater the number of crimps that develop. However, considering various physical properties of the resulting nonwoven fabric, the heat treatment temperature may be in the range of 130 to 180 ° C. preferable. The heat treatment temperature in this case refers to the temperature in the dry hot air treatment, but when it is difficult to uniformly heat the nonwoven fabric, under a humidity such as steam,
For example, the crimp can be developed by heating to 90 ° C. The composite fiber of the present invention may be mixed with other fibers to form a non-woven fabric, in which case a non-woven fabric having high stretchability and high elastic recovery can be obtained by appropriately selecting the non-woven fabric manufacturing conditions.

[0032]

The present invention will be described in detail below with reference to Examples.
The present invention is not limited to these examples.
In addition, each measured value in an Example is measured by the following method. (1) Intrinsic viscosity of each polymer ([η] dl / g) Phenol / tetrachloroethane mixed solvent (weight ratio 1 /
In 1), it was measured at 30 ° C. (2) Measurement of the number of crimps before crimp development treatment (pieces / 25 mm) Single yarn is taken out and 25 mm under a load of 2 mg / denier
The number of crimps in between was measured. The average value of 20 single yarns was taken as the number of spiral crimps. (3) Measurement of the number of crimps after crimping treatment (pieces / 25 mm) 120 ° C. at 130 ° C. under a load of 1 mg / denier on the drawn yarn.
Second dry hot air treatment was performed to develop crimps, and the number of crimps for 25 mm was measured. The average value of 20 drawn yarns was taken as the number of crimps.

Example 1 As a polymer A, norbornane-2,3-dimethano-
Polyethylene terephthalate ([η] _A = 0.670) copolymerized with 10 mol% of ethylene, and polyethylene terephthalate ([η] _B = 0.600) as B polymer, A side-by-side type composite fiber having a ratio of 1/1 was obtained at a spinning temperature of 297 ° C. and a take-up speed of 1000 m / min. The obtained spun yarn was subjected to a maximum draw ratio of 0.
Stretched at a stretch ratio of 8 times to obtain 5250 denier / 252.
A 0 filament drawn yarn was obtained. The number of spiral crimps of the drawn yarn was 8.5 / 25 mm. On the other hand, the drawn yarn obtained was subjected to mechanical crimping of 12 pieces / 25 mm to obtain 51 mm.
When the card treatment was performed after cutting, the card passability was good and no nep or unopened portion was generated. When a spun yarn was prepared using the yarn after passing through the card of the drawn yarn which was not mechanically crimped, and subjected to crimp expression treatment at 130 ° C., a large number of crimps were expressed, which was excellent. The yarn had elasticity and elastic recovery. Further, the weight ratio of the fiber after passing through the card and the polyethylene terephthalate fiber is 2: 1.
Then, a nonwoven fabric having a basis weight of 60 g / m ² was prepared by hydroentangling.
When this nonwoven fabric was subjected to dry hot air treatment at 140 ° C. for 5 minutes, an area shrinkage of 41.6% was confirmed, and these nonwoven fabrics were good in both stretchability and elastic recovery.

Examples 2 to 4 Drying was carried out in the same manner as in Example 1 except that the intrinsic viscosity of the B polymer was changed as shown in Table 1 and the drawn yarn was heat-treated at 75 ° C. with 0% shrinkage treatment. Hot air treatment was performed to develop crimps. The results are shown in Table 1. Further, in the same manner as in Example 1, the drawn yarn that had been heat-treated at 75 ° C. was mechanically crimped to obtain raw cotton and subjected to card treatment. No unopened part was generated. Further, the weight ratio of the yarn after passing the card of the non-machined crimped yarn and the polyethylene terephthalate fiber is 2: 1.
Then, a nonwoven fabric having a basis weight of 60 g / m ² was prepared by hydroentangling.
When this nonwoven fabric was subjected to dry hot air treatment at 140 ° C. for 5 minutes, an area shrinkage of about 30 to 60% was confirmed, and these nonwoven fabrics were good in both stretchability and elastic recovery.

Example 5 12 yarns / 25 were obtained in the same manner as in Example 4 except that the shrinking treatment after stretching was changed to 5%.
When the raw cotton was obtained by subjecting the raw cotton to a mechanical crimping of mm, the card passing property was good, and no nep or unopened portion was generated. The fiber after passing through the card and the polyethylene terephthalate fiber were hydroentangled at a weight ratio of 2: 1 to prepare a nonwoven fabric having a basis weight of 60 g / m ² . 14 on this non-woven fabric
When subjected to hot air treatment at 0 ° C. for 5 minutes, an area shrinkage of 52.0% was confirmed, and these nonwoven fabrics were good in both stretchability and elastic recovery.

Comparative Examples 1-2 In Example 1, norbornane-2,3-dimethano-
Copolymerization amount of 0.5 mol% (Comparative Example 1), 30 mol%
The composite fiber was spun and stretched in the same manner except that it was changed to (Comparative Example 2). The fiber of Comparative Example 2 was difficult to draw, and a satisfactory drawn yarn could not be obtained. The number of crimps of the drawn yarn of Comparative Example 1 was 2.1 pieces / 25 mm. 10. The drawn yarn was subjected to a dry hot air treatment at 130 ° C. for 120 seconds under a load of 1 mg / denier to develop crimps.
It was 4 pieces / 25 mm. 12 pieces / 2 in the obtained drawn yarn
After mechanical crimping of 5 mm and cutting to 51 mm, a card treatment was carried out. As a result, good card passing property was observed and no nep or unopened portion was generated, but fibers after passing the card. The non-woven fabric prepared by hydroentangling polyethylene and polyethylene terephthalate fiber at a weight ratio of 2: 1 has an area shrinkage rate of about 9.8% even when subjected to dry hot air treatment at 140 ° C. for 5 minutes. ,
Both stretchability and elastic recovery were poor.

Example 6 In Example 1, norbornane-2,3-dimethano-
The conjugate fiber was spun and drawn in the same manner except that tricyclodecane dimethanol was used instead of the resin. The number of spiral crimps of the drawn yarn was 0/25 mm. When the drawn yarn was subjected to a dry hot air treatment at 130 ° C. for 120 seconds under a load of 1 mg / denier to develop crimp, 74.3
The number was 25 / mm. On the other hand, when the obtained drawn yarn was subjected to mechanical crimping of 12 yarns / 25 mm and cut to 51 mm and then subjected to carding, the card passing property was good and no nep or unopened portion was generated. There wasn't. Further, the fibers after passing through the card of the drawn yarn not subjected to mechanical crimping and the polyethylene terephthalate fibers were hydroentangled at a weight ratio of 2: 1 to prepare a nonwoven fabric having a basis weight of 60 g / m ² . 140 on this non-woven fabric
When subjected to dry hot air treatment at 5 ° C for 5 minutes, 62.2%
Area shrinkage was confirmed, and these nonwoven fabrics were good in both elasticity and elastic recovery.

Examples 7 to 9 Drying was carried out in the same manner as in Example 1 except that the intrinsic viscosity of the B polymer was changed as shown in Table 1 and the drawn yarn was heat-treated at 90 ° C. with 0% shrinkage treatment. Hot air treatment was performed to develop crimps. The results are shown in Table 1. Further, in the same manner as in Example 1, the heat treated drawn yarn was subjected to mechanical crimping of 12 yarns / 25 mm to obtain raw cotton and subjected to card treatment. There was no nep or unopened part. Further, the non-mesh crimped drawn yarn after passing through the card and the polyethylene terephthalate fiber were hydroentangled at a weight ratio of 2: 1 to prepare a nonwoven fabric having a basis weight of 60 g / m ² . When this non-woven fabric was subjected to dry hot air treatment at 140 ° C. for 5 minutes, an area shrinkage of about 40 to 57% was confirmed, and these non-woven fabrics were good in both elasticity and elastic recovery.

Example 10 A stretched yarn which was heat treated in the same manner as in Example 9 except that the shrinking treatment after stretching was changed to 5% was subjected to mechanical crimping to obtain raw cotton, and subjected to card treatment. As a result, the card passage property was good, and no nep or unopened portion was generated. The fiber after passing through the card and the polyethylene terephthalate fiber were hydroentangled at a weight ratio of 2: 1 to prepare a nonwoven fabric having a basis weight of 60 g / m ² . When this non-woven fabric was subjected to dry hot air treatment at 140 ° C. for 5 minutes, an area shrinkage of 45.2% was confirmed, and these non-woven fabrics were good in both elasticity and elastic recovery.

Comparative Examples 3 to 4 The same as Example 7 except that the copolymerization amount of tricyclodecane dimethanol was changed to 0.5 mol% (Comparative Example 3) and 30 mol% (Comparative Example 4). The composite fiber was spun and drawn. The fiber of Comparative Example 4 was difficult to draw, and a satisfactory drawn yarn could not be obtained. The number of crimps of the drawn yarn of Comparative Example 3 was 0/25 mm. 1 mg / in this drawn yarn
When a dry hot air treatment was performed at 130 ° C. for 120 seconds under a load of denier to develop crimps, 21.0 pieces / 25
mm. The drawn yarn thus obtained was mechanically crimped at 12 yarns / 25 mm, cut into 51 mm, and then subjected to carding. As a result, card passing was good and no nep or unopened portion was generated. However, the non-woven fabric prepared by hydroentangling the fiber after passing the card and the polyethylene terephthalate fiber at a weight ratio of 2: 1 has an area even if subjected to dry hot air treatment at 140 ° C. for 5 minutes. The shrinkage ratio was about 11.4%, and both stretchability and elastic recovery were poor.

Comparative Example 5 In Example 1, norbornane-2,3-dimethano-
5-sodium sulfoisophthalic acid instead of 2.
The composite fiber was spun and drawn in the same manner except that 5 mol% and 5.0 mol% of isophthalic acid were used. The obtained spun yarn was drawn in a warm water bath at 75 ° C. at a draw ratio of 0.85 times the maximum draw ratio to obtain a drawn yarn of 4,500 denier / 2160 filaments. The number of spiral crimps of the drawn yarn was 19.2 / 25 mm. 12 for the obtained drawn yarn
After mechanical crimping of 25 mm / piece and cutting to 51 mm,
Card processing was performed, but many neps and unopened portions were generated. On the other hand, the stretched yarn not subjected to the mechanical crimp has 90
Heat treated at ℃, the number of crimps reduced to 8 pieces / 25mm, 12m / 25mm mechanical crimps applied to 51m
After being cut into m, a card treatment was carried out. As a result, the card passing property was satisfactory. The fiber after passing through the card and the polyethylene terephthalate fiber were hydroentangled at a weight ratio of 2: 1 to prepare a nonwoven fabric having a basis weight of 60 g / m ² . This non-woven fabric was treated with dry hot air at 150 ° C for 5 minutes.
The area shrinkage was only%, and the nonwoven fabric was poor in both elasticity and elastic recovery.

[0042]

[Table 1]

[0043]

The composite fiber of the present invention has a very small number of spiral crimps of 13 pieces / 25 mm or less in the state after spinning / drawing, so that the processability during carding is good and nep or unopened fiber is obtained. Since no part is generated and the crimp development ability by the subsequent heat treatment is excellent, it becomes possible to make the nonwoven fabric or the woven or knitted fabric rich in stretchability and elastic recovery.

Claims (4)

[Claims] 1. A polyethylene terephthalate-based polyester or a polybutylene terephthalate-based polyester copolymerized with a compound having a norbornane skeleton, and the polyester are eccentrically bonded to each other, and the latent winding at 130 ° C. A polyester composite fiber having a number of crimps of 40/25 mm or more and having a crimp number of 13/25 mm or less before crimping. 2. A polyethylene terephthalate-based polyester or a polybutylene terephthalate-based polyester obtained by copolymerizing a compound having a norbornane skeleton, and the polyester are eccentrically joined, and 40 pieces at 130 ° C. / 25 mm or more, which is a conjugate fiber having a latent crimping ability to develop a spiral crimp, and the number of crimps after the crimping treatment is 40/25 mm or more. 3. The polyester conjugate fiber according to claim 1 or 2, wherein the compound having a norbornane skeleton is a compound represented by the following formula I. Embedded image (In the formula, X ₁ and X ₂ are respectively CH ₂ OH or C
Represents OOR, R represents a lower alkyl group, and m represents 0 or 1. ) 4. The compound having a norbornane skeleton is a compound represented by the following formula II.
Alternatively, the polyester conjugate fiber according to claim 2. Embedded image (In the formula, X ₃ and X ₄ are respectively CH ₂ OH or C
Represents OOR ', and R'represents a lower alkyl group. )