JP2004263314A - Conjugate yarn having excellent processability and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polytrimethylene terephthalate(PTT)-based conjugate yarn whose breakage is eliminated, when false-twisted, and which eliminates a non-untwisting state and knot-like defects, when the obtained false-twisted yarn is used as the warp and/or weft of a lining fabric. <P>SOLUTION: This PTT-based conjugate yarn comprising the group of single fibers each prepared by sticking polytrimethylene terephthalate as at least one of components constituting the single fiber to a polyester as the other component in a side-by-side type or an eccentric sheath-core type is characterized in that the intrinsic viscosity of the polytrimethylene terephthalate is 0.6 to 1.6 dl/g and that the number of produced mustache-like signals having heights of ≥5% based on an average dtex value is ≤10, when the changes of fineness (normal method) are measured over a conjugate fiber length of 1,000 m. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

フルスケール±１２．５％で測定されたＵ％チャートで、平均繊度に対して太デシテックス方向に５％を越えるヒゲ状シグナルをコブ状単糸として、測定糸長１０００ｍに存在するコブ状単糸の数を測定した。
【００３９】
（３）交絡度（ＣＦ）
エンタングルメントテスター（Ｒｏｔｈｓｃｈｉｌｄ社製）：Ｒ２０７２型を用い、糸速度５ｍ／分でトリップレベル１５ｃＮおよび５０ｃＮにて、各々触針トリップ回数３０回を測定し、交絡度を求めた。
（４）紡糸安定性
１錘当たり８エンドの紡口を装着した溶融紡糸−連続延伸機を用いて、各実施例ごとに２日間の溶融紡糸−連続延伸を行った。
この期間中の糸切れの発生回数と、得られた複合繊維パッケージに存在する毛羽の発生頻度（毛羽発生パッケージの数の比率）から以下のように判定した。
◎ ： 糸切れ０回、毛羽発生パッケージ比率 ５％以下
○ ： 糸切れ２回以内、毛羽発生パッケージ比率 １０％未満
× ： 糸切れ３回以上、毛羽発生パッケージ比率 １０％以上
【００４０】
（５）仮撚加工性
下記条件で仮撚加工を行い、９６錘／台で仮撚加工を連続して実施した際の１日当たりの糸切れ回数で解じょ性、仮撚加工性を評価した。

フィードローラー以降、ヒーター中で糸切れした回数で、以下のように判定した。
◎：糸切れ回数が１０回／日・台未満で非常に良好
○：糸切れ回数が１０〜３０回／日・台で良好
×：糸切れ回数が３０回／日・台を越え、工業的生産が困難
【００４１】
（６）加工糸品位
織物の調整
織物の作成は以下のように行った。経糸に５６ｄｔｅｘ／２４ｆのＰＴＴ単一の繊維（旭化成「ソロ」）の無撚糊付け糸を用い、緯糸に本発明の各実施例および比較例の５６ｄｔｅｘ／２４ｆ複合繊維を用いて平織物を作成した。

得られた生機を、オープンソーパーにて９５℃で連続精練後、１２０℃でシリンダー乾燥した後、液流染色機にて１２０℃で染色を行った。次いで、１７５℃で仕上、幅だし熱セットの一連の処理を行った。
【００４２】
布帛評価
得られた織物を、熟練した検査技術者が検査し、緯の染め品位を以下のように判定して加工糸の品位を評価した。
◎ ： 未解撚や節状欠点がなく、極めて良好
○ ： 未解撚や節状欠点が少なく、良好
× ： 未解撚や節状欠点が多数あり、不良
（７）総合評価
◎ ： 紡糸性、仮撚加工安定性、織物品位共に極めて良好
○ ： 紡糸性、仮撚加工安定性、織物品位共に良好
× ： 紡糸性、仮撚加工安定性、織物品位のいずれかが不良
【００４３】
【実施例１〜４、比較例１】
本実施例では、高固有粘度粉体の含有率の効果について説明する。
一方の成分として、酸化チタンを０．４重量％含む平均固有粘度［η］＝１．３０ｄｌ／ｇのＰＴＴペレットを用いた。
このＰＴＴペレットに、２４メッシュのフィルターを通過する固有粘度［η］＝１．５０ｄｌ／ｇ（平均固有粘度の１．１５倍）の粉体の含有率を表１に示すように異ならせて押出を行った。他方の成分として酸化チタンを０．４重量％含む平均固有粘度０．９２のＰＴＴペレット用いた。
これらを図４のような紡糸機で、マードック型スクリューを装着した押出機を用い、溶融時の押出温度を２７０℃で、且つせん断速度２０２（１／秒）の条件で溶融して、紡口より吐出し紡糸した。冷却固化したフィラメントを、３対のゴデットロールを有する巻取機を用いて、５６ｄｔｅｘ／２４フィラメントＰＴＴ複合繊維を製造した。
【００４４】
本実施例における紡糸条件は、以下のごとくである。

【００４５】

得られたＰＴＴ系複合繊維を、先に示した加工条件で仮撚して、仮撚加工糸を得た。紡糸性、仮撚加工性及び仮撚加工糸の品位を表１に示す。
表１から明らかなように、高固有粘度の粉体含有率が本発明の範囲であれば、良好な紡糸性、仮撚加工性及び、仮撚加工糸の品位を有していた。
【００４６】
【表１】

【００４７】
【実施例５〜７、比較例２〜５】
本実施例では、溶融押出条件の効果について説明する。
実施例２に示す、高固有粘度粉体含有のＰＴＴペレットを用いて溶融押出を行うにあたり、スクリュー型式、押出温度及びせん断速度を表２に示すように異ならせて押出を行った。
得られたＰＴＴ系複合繊維を、実施例１と同様にして仮撚加工糸を得た。紡糸性、仮撚加工性及び仮撚加工糸の品位を表２に示す。
表２から明らかなように、本発明の溶融押出条件により、良好な紡糸性、仮撚加工性及び良好な品位の仮撚加工糸が得られた。
【００４８】
【表２】

【００４９】
【発明の効果】
本発明によれば、ＰＴＴ系複合繊維を仮撚する際の糸切れを解消し、且つ得られた仮撚加工糸を裏地織物の経糸及び／又は緯糸に使用した際に、未解撚や節状欠点を解消することが可能である。
また、本発明によれば、優れた品位とソフトな風合い及び際立ったストレッチ特性を発現可能な、ＰＴＴ系複合繊維及びそれを工業的に安定に製造する製造法が提供される。
【図面の簡単な説明】
【図１】「コブ」状単糸の一例を示す模式図である。
【図２】「コブ」状単糸が多数存在する、ＰＴＴ系複合繊維のＵ％チャートの一例を示す概略図である。
【図３】「コブ」状単糸が存在しない、ＰＴＴ系複合繊維のＵ％チャートの一例を示す概略図である。
【図４】本発明の製造方法に用いる複合紡糸設備の模式図である。
【符号の説明】
１：ポリマーチップ乾燥機
２：押出機
３：ポリマーチップ乾燥機
４：押出機
５：ベンド
６：ベンド
７：スピンヘッド
８：スピンパック
９：紡糸口金
１０：マルチフィラメント
１１：非送風領域
１２：冷却風
１３：仕上げ剤付与装置
１４：第１ゴデットロール
１５：第２ゴデットロール
１６：第３ゴデットロール
１７：複合繊維パッケージ[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a polytrimethylene terephthalate-based composite fiber suitable for use in a processed yarn fabric and a method for producing the same. More specifically, when untwisting and knot-like defects occur when the obtained false twisted yarn is used for warp and / or weft of woven fabric, the yarn breakage during false twisting of the composite fiber is eliminated. In addition, the present invention relates to a polytrimethylene terephthalate-based composite fiber capable of exhibiting excellent quality, a soft touch and outstanding stretch properties, and a method for industrially stably producing the same.
[0002]
[Prior art]
In recent years, among knitted fabrics, stretch knitted fabrics having a stretch property have been strongly demanded from the viewpoint of wearing.
In order to satisfy such a demand, for example, a large number of knitted fabrics provided with stretchability by mixing polyurethane fibers are used.
However, polyurethane fibers have problems such that the dyeing process is complicated because they are not easily dyed by polyester dyes, and the fibers are embrittled during long-term use, and the performance is reduced.
For the purpose of avoiding such drawbacks, application of crimped yarn of polyester fiber instead of polyurethane fiber has been studied.
[0003]
In recent years, PTT-based crimped yarns have been proposed, focusing on the elongation and recovery of polytrimethylene terephthalate (hereinafter, referred to as PTT).
In particular, many latently crimped fibers have been proposed in which two types of polymers are bonded side-by-side or eccentrically to develop crimp after heat treatment.
Patent Literature 1 to Patent Literature 10 and the like are cited as prior arts relating thereto.
These include side-by-side type bicomponent composite fibers using PTT for at least one component, or PTT having different intrinsic viscosities for both components, and eccentric sheath-core composite fibers (hereinafter, both types). And PTT-based composite fibers). This PTT-based conjugate fiber is characterized by having a soft feel and good crimp development characteristics. These prior arts describe that they have stretchability and elongation recovery properties, and can be applied to various stretch knitted fabrics or bulky knitted fabrics by utilizing these characteristics.
[0004]
Patent Documents 4, 11 and 9 disclose a PTT-based composite having high crimpability and excellent elongation recovery by using a high-viscosity PTT having an intrinsic viscosity of 0.8 to 2 as one component. It is proposed that a fiber be obtained. In order to produce a PTT polymer having a high intrinsic viscosity, industrially, a low-viscosity polymer having an intrinsic viscosity of about 0.5 to 0.7 dl / g is produced as pellets by a melt polymerization method, and then about 0.2 wt. Generally, a two-stage method of producing a polymer having a high viscosity of 8 dl / g or more is employed.
The reason is that, in the melt polymerization of PTT, if it is desired to obtain a polymer having an intrinsic viscosity of about 0.8 dl / g or more in a one-step method, it is necessary to employ polymerization conditions at a high temperature for a long time. This is because the thermal decomposition of the polymer becomes remarkable, and it becomes difficult to produce a polymer industrially safely and stably due to an increase in by-products such as trimethylene glycol cyclic dimer and generation of coloring due to the thermal decomposition.
[0005]
In the two-stage method employing the solid-state polymerization method, generation of by-products and pyrolysis gas is reduced, and a PTT polymer having a desired intrinsic viscosity can be easily obtained.
However, according to our study, the low-viscosity PTT polymer obtained by melt polymerization has a characteristic that the polymer is easily crushed due to the high crystallinity of PTT. When the pellets are crushed, a large amount of so-called powder having a size of about 24 mesh or less is generated. When pellets containing such a powder are subjected to solid-phase polymerization, a difference occurs in the degree of polymerization reached between the powder and the pellet. That is, it was found that the intrinsic viscosity of the powder was 1.1 times or more higher than the average intrinsic viscosity of the pellet.
When a PTT polymer containing such a powder having a high intrinsic viscosity is used as one component of the side-by-side type or the eccentric sheath-core type composite fiber, yarn breakage occurs frequently during spinning, and the spinnability is impaired. In addition, it was revealed that a "cob" -like single yarn was generated in the obtained composite fiber.
[0006]
FIG. 1 shows a schematic diagram of an optical micrograph of a “cob” -shaped single yarn.
When the U% measurement is performed on the conjugate fiber including the "cob" -shaped single yarn, the "cob" portion is detected as a mustache signal of 5% or more with respect to the average denier.
FIG. 2 shows a part of an example of a U% chart in which a beard signal is detected.
FIG. 3 shows a part of an example of the U% chart in which the beard signal has been eliminated.
Although the reason for the occurrence of the "cob" -shaped single yarn is not clear, the powder with a high intrinsic viscosity is discharged from the spinning hole with no melting or high melting viscosity, without being drawn even in subsequent drawing or drawing false twisting processing It is presumed to be present in the conjugate fiber.
The inventors of the present invention have found that when false-twisting a composite fiber containing such a "cob" -like single yarn, not only yarn breakage occurs during processing but also untwisting defects occur in the false-twisted yarn. It became clear by. Such a problem is not disclosed at all in the prior art.
[0007]
Patent Document 4 discloses a conjugate fiber having a fineness variation of U%, but it was impossible to detect a beard signal because the measured yarn length was only 50 m. Further, Patent Documents 1 and 5 disclose that a high-quality woven fabric can be obtained from a conjugate fiber. However, such a problem is not considered at all because there is no use as a false twisted yarn. .
Further, as proposals regarding powders contained in PTT pellets, Patent Documents 12 and 13 disclose proposals for reducing the content of a polymer whose melting point is higher than the average melting point by 3 ° C. or more, and proposals for reducing the amount of powder. Have been. However, there is no disclosure at all about the existence of a powder having a high intrinsic viscosity with respect to the average degree of polymerization or the influence on the false twisting property of the powder.
Therefore, a PTT-based conjugate fiber comprising PTT as one component, which does not cause yarn breakage during false twisting and does not cause untwisted defects in the false twisted yarn, and a stable production method thereof The emergence of was strongly desired.
[0008]
[Patent Document 1]
JP-B-43-19108
[Patent Document 2]
JP 2000-239927 A
[Patent Document 3]
JP 2000-256918 A
[Patent Document 4]
JP 2001-55634 A
[Patent Document 5]
JP 2001-131837 A
[Patent Document 6]
European Patent No. 1059372
[Patent Document 7]
U.S. Pat. No. 6,306,499
[Patent Document 8]
JP 2001-40537 A
[Patent Document 9]
JP-A-2002-61031
[Patent Document 10]
JP-A-2002-54029
[Patent Document 11]
JP 2001-288621 A
[Patent Document 12]
JP-A-11-226944
[Patent Document 13]
JP-A-11-226947
[0009]
[Problems to be solved by the invention]
An object of the present invention is to eliminate breakage during false-twisting of PTT-based composite fibers, and to use untwisted or knotted yarn when using the obtained false-twisted yarn for warp and / or weft of a lining fabric. It is to eliminate the shape defect.
An object of the present invention is to provide a PTT-based conjugate fiber capable of exhibiting excellent quality, a soft feel and outstanding stretch properties when false-twisted yarn is used, and a method for industrially stably producing the same.
[0010]
[Means for Solving the Problems]
The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, by specifying the number of knotted single yarns contained in the single yarn constituting the composite fiber, good false twisting processability and excellent quality have been achieved. It was found that a false twisted yarn was obtained, and the present invention was completed.
That is, the first invention of the present invention relates to a method for producing a single yarn, wherein at least one component is a polytrimethylene terephthalate and the other component is a polyester composed of a side-by-side type or an eccentric sheath. A composite fiber comprising a group of single yarns bonded to a core mold, wherein the intrinsic viscosity of polytrimethylene terephthalate is 0.6 to 1.6 dl / g, and the fineness varies U% over a composite fiber yarn length of 1,000 m (normal method) Is a polytrimethylene terephthalate-based composite fiber, characterized in that the number of mustache signals whose decitex is 5% or more higher than the average value when measured is 10 or less.
[0011]
A second invention of the present invention comprises a single yarn group in which two polyester components are bonded in a side-by-side type or an eccentric sheath-core type, and has an average intrinsic viscosity of 0.1 as at least one component constituting the single yarn. The production of polytrimethylene terephthalate-based composite fibers, characterized by simultaneously satisfying the following requirements (A) and (B) when producing composite fibers using the polytrimethylene terephthalate pellets of 6 to 1.6: Is the way.
(A) having an intrinsic viscosity that is 1.1 times or more higher than the average intrinsic viscosity of the high-viscosity component, and having a content of powder passing through a 24 mesh filter of 2% by weight or less,
(B) Melting is performed at an extrusion temperature of 250 to 280 ° C. and a shear rate of 40 to 200 (1 / second) during melt extrusion.
[0012]
Hereinafter, the present invention will be described in detail.
In the present invention, two polyester components are side-by-side type, or a composite fiber composed of a single yarn group bonded to an eccentric sheath-core type, at least one component constituting the single yarn is PTT, The target is a PTT-based composite fiber in which the other component is made of another polyester.
That is, a combination of PTT and another polyester or a combination of PTTs is targeted.
At least one of the single yarns constituting the PTT-based composite fiber in the present invention is a PTT homopolymer or a copolymerized polytrimethylene terephthalate containing 10 mol% or less of other ester repeating units.
[0013]
Representative examples of the copolymer component include the following.
Examples of the acidic component include aromatic dicarboxylic acids such as isophthalic acid and 5-sodium sulfoisophthalic acid, and aliphatic dicarboxylic acids such as adipic acid and itaconic acid. Examples of the glycol component include ethylene glycol, butylene glycol, polyethylene glycol and the like. Hydroxycarboxylic acids such as hydroxybenzoic acid are also examples. A plurality of these may be copolymerized.
[0014]
Other polyester components of the single yarn constituting the PTT-based composite fiber include, in addition to PTT, polyethylene terephthalate (hereinafter, referred to as PET), polybutylene terephthalate (hereinafter, referred to as PBT), or copolymerized with the third component. Used.
Representative examples of the copolymer component include the following.
Examples of the third component include aromatic dicarboxylic acids typified by isophthalic acid and 5-sodium sulfoisophthalic acid, and aliphatic dicarboxylic acids typified by adipic acid and itaconic acid. Examples of the glycol component include ethylene glycol, butylene glycol, polyethylene glycol and the like. Hydroxycarboxylic acids such as hydroxybenzoic acid are also examples. A plurality of these may be copolymerized.
[0015]
The method for producing the PTT polymer used in the present invention may be a known method. A one-step method in which the degree of polymerization is equivalent to a predetermined intrinsic viscosity only by melt polymerization, or a degree of polymerization is increased by melt polymerization until a certain intrinsic viscosity is reached, and then to a degree of polymerization equivalent to the predetermined intrinsic viscosity by solid phase polymerization This is a two-step method.
The latter two-stage method combining solid phase polymerization is preferred from the viewpoint of reducing the content of by-products such as cyclic dimers.
The PTT polymer used in the present invention preferably has a trimethylene terephthalate cyclic dimer content of 2.5% by weight or less. More preferably, the content of trimethylene terephthalate cyclic dimer is less than 1.1% by weight. A more preferred trimethylene terephthalate cyclic dimer content is 1.0% by weight or less.
[0016]
In the present invention, it is necessary that polytrimethylene terephthalate, which is at least one component constituting the single yarn, has an intrinsic viscosity of 0.6 to 1.6 dl / g.
When the intrinsic viscosity of PTT is less than 0.6 dl / g, the obtained false twisted yarn has low crimping performance and insufficient stretchability and stretchback property. If the intrinsic viscosity of PTT exceeds 1.6 dl / g, the melt viscosity during spinning becomes extremely high, and breakage occurs during spinning, making stable spinning difficult.
The preferred intrinsic viscosity of PTT is 0.8 to 1.4 dl / g.
In the present invention, the difference in intrinsic viscosity between the two polyester components is preferably 0.05 to 0.8 dl / g.
By having such an intrinsic viscosity difference, even if the false twisted yarn is greatly constrained in the knitted fabric, excellent stretchability and stretchback property can be exhibited.
[0017]
The average intrinsic viscosity of the PTT-based composite fiber in the present invention is preferably in the range of 0.6 to 1.2 dl / g.
If it is less than / g, the strength of the obtained composite fiber is low, the mechanical strength of the fabric is reduced, and its use in sports applications and the like that require strength is restricted.
If the average intrinsic viscosity exceeds 1.2 dl / g, thread breakage occurs during the production of the conjugate fiber, and stable production becomes difficult.
A more preferred average intrinsic viscosity is 0.8 to 1.2 dl / g.
In the present invention, it is more preferable that both components constituting the single yarn are PTT. If both components are PTT, the stretch-back property of the false twisted yarn becomes more excellent, which is preferable.
[0018]
In the present invention, the mixing ratio of the two polyester components in the cross section of a single yarn is preferably such that the ratio of the high-viscosity component to the low-viscosity component is 40/60 to 70/30.
When the ratio of the high viscosity component is less than 40%, the yarn strength becomes less than 2 cN / dtex, and the tear strength of the fabric becomes insufficient. On the other hand, when the ratio of the high-viscosity component is more than 70%, the crimping performance decreases. A more desirable compounding ratio is 45/55 to 65/35.
In the present invention, a composite fiber composed of a single yarn group bonded to a side-by-side type or an eccentric sheath-core type, and when a fineness variation U% (normal method) is measured over a composite fiber yarn length of 1,000 m, It is necessary that the number of mustache signals whose decitex is higher than the average value by 5% or more is 10 or less.
[0019]
The whisker signal specified in the present invention indicates the number of knotted single yarns. The knotted single yarn can be easily obtained by a method of measuring the fineness variation U% in a normal mode described later. However, there are other methods such as a method of providing a narrow slit and passing a conjugate fiber between them. Can be confirmed. The bumpy single yarn can be observed with an optical microscope.
The knotted single yarn has a diameter of at least twice the average diameter of the single yarn and a length of 0.5 to 5 mm. When such a bumpy single yarn is present, when the fineness variation U% is measured by a normal method, a signal whose decitex is 5% or more higher than the average value is detected.
[0020]
If the diameter is smaller than this, yarn breakage and untwisting defects do not occur in false twisting. If the length is longer than this, yarn breakage occurs during spinning and is not included in the conjugate fiber.
If the number of the knotted single yarns exceeds 10/1000 m, yarn breakage occurs when passing through running guides, twister belts, disks, etc. during false twisting, and industrially stable false twisting. Becomes difficult. Further, untwisted portions remain in the false twisted yarn, which causes defects such as abnormal dot-like dyeing in knitted fabrics.
The content of the knotted single yarn is preferably 5 pieces / 1000 m or less, more preferably 2 pieces / 1000 m or less. Of course, 0 / 1000m is most preferable.
[0021]
It is preferable that the PTT-based conjugate fiber of the present invention is provided with light entanglement. The light confounding has a confounding degree (CF) of 2 to 50 pieces / m at a measured strength (trip level) of 15 cN, and a confounding degree (CF) of 0 to 2 pieces / m at a measured strength of 50 cN. Indicates confounding.
The confounding strength can be easily measured by setting the set stylus trip level in the measurement of the confounding degree (CF).
When the set value of the measured tenacity (trip level) is as small as 15 cN, the PTT-based conjugate fiber of the present invention has a large number of entanglements of 2 to 50 pieces / m in the measured degree of entanglement (CF). However, when the set value of the measurement strength is as large as 50 cN, the measured confounding degree (CF) is 0 to 2 pieces / m.
[0022]
In other words, the lightly entangled material is excellent in handleability such as depackaging of the PTT-based composite fiber from the package and the pan, and the untwisted yarn is not untwisted in the false twisting process because the entanglement is released. The effect of preventing twisting or the like is obtained.
The preferred confounding strength is a confounding degree (CF) of 2 to 20 pieces / m at a measured strength of 15 cN, and a confounding degree (CF) of 0 pieces / m at a measured strength of 50 cN.
The fineness and single yarn fineness of the PTT-based composite fiber of the present invention are not particularly limited, but the fineness is 20 to 300 dtex and the single yarn fineness is 0.5 to 20 dtex.
Further, the cross-sectional shape of the single yarn is not particularly limited, and may be a round, elliptical, Y, W-shaped irregular cross-section, a hollow cross-sectional shape, or the like.
The PTT-based composite fiber of the present invention includes a matting agent such as titanium oxide, a heat stabilizer, an antioxidant, an antistatic agent, an ultraviolet absorber, an antibacterial agent, various pigments, and the like, as long as the effects of the present invention are not impaired. May be contained or copolymerized.
In particular, when an inorganic substance such as titanium oxide is contained, it is preferable to use a fine particle having a particle size of 0.01 to 5 μm to reduce the fineness variation U% (normal method) over a composite fiber yarn length of 1000 m. When measured, the number of mustache signals whose decitex is 5% or more higher than the average value is preferable to be 10 or less.
The content of the inorganic substance referred to here is preferably contained in the resin constituting the conjugate fiber, and may be both or one of the PTT resin and the other component resin. The content is preferably from 0 to 7% by weight. When both are contained, a matting effect can be expected in the case of titanium oxide, and when it is contained in one of the two, it is preferable to use a specially shaped cross-section, since it gives a feeling of strange gloss.
[0023]
Hereinafter, the manufacturing method according to the second invention of the present invention will be described.
In the production method of the present invention, it is necessary to spin using PTT pellets having an intrinsic viscosity of 0.6 to 1.6 dl / g.
When the intrinsic viscosity of the PTT pellet is less than 0.6 dl / g, the breaking strength of the obtained conjugate fiber becomes about 2 cN / dtex or less, and the usage application as a fabric is limited. If the intrinsic viscosity of the PTT pellet exceeds 1.6 dl / g, the melt viscosity of the PTT becomes extremely high, melt kneading becomes insufficient, and it becomes difficult to eliminate the bumpy single yarn.
In the production method of the present invention, the powder contained in the PTT pellets has an intrinsic viscosity of 1.1 times or more than the average intrinsic viscosity of the high-viscosity component, and contains a powder passing through a 24 mesh filter. It is important that the ratio be 2.0% by weight or less.
If the powder content exceeds 2.0% by weight, it is difficult to eliminate the occurrence of the bumpy single yarn, no matter how the temperature and the kneading conditions are adjusted during melting. The powder content is preferably as small as possible, and is preferably 1.0% by weight or less. Most preferably, it is not contained.
[0024]
In the production method of the present invention, it is necessary to melt at an extrusion temperature of 250 to 280 ° C. during melt extrusion and at a shear rate of 40 to 200 (1 / second) applied to the polymer during melting.
If the temperature at the time of melt extrusion is lower than 250 ° C., no matter how high the shear rate is, generation of the bumpy single yarn is not eliminated.
When the temperature at the time of melt extrusion exceeds 280 ° C., the molecular weight of PTT having a high degree of polymerization is significantly reduced, and coloring or decomposition gas is generated due to thermal decomposition. The preferred melt extrusion temperature is 255-275 ° C.
Shear during melt extrusion is applied between the barrel and the screw of the extruder.
[0025]
The extruder shear rate is calculated by the following equation.
Shear rate (1 / sec) = π x D x n / 60 · C
Here, D is the barrel inner diameter (mm) of the extruder, n is the screw rotation speed (times / minute), and C is the clearance (mm) between the barrel and the screw.
In the production method of the present invention, if the shear rate is less than 40 (1 / sec), it is difficult to eliminate the occurrence of the bumpy single yarn even at a high melting temperature.
When the shear rate exceeds 200 (1 / second), the generation of the bumpy single yarn is eliminated, but the shear heat generation of the polymer becomes excessive, resulting in a sharp decrease in molecular weight and coloring. A preferred shear rate is 50 to 150 (1 / second).
[0026]
Hereinafter, a specific method for producing the conjugate fiber of the present invention will be described with reference to the drawings.
FIG. 4 is a schematic diagram of a composite spinning facility used in the production method of the present invention.
First, PTT pellets obtained by drying one of the components in the dryer 1 to a moisture content of 20 ppm or less are supplied to the extruder 2 set to a temperature of 250 to 280 ° C. and melted. The other component is similarly melted by the dryer 3 and the extruder 4.
A known screw is mounted on the extruder 2 and the extruder 4, and a necessary shear rate is given by adjusting the screw shape and the screw groove depth.
As the shape of the screw, a full flight type, a Murdoch type or a dalmage type at the tip is employed. More preferably, the extruder 2 employs a screw having a Murdoch-type tip.
[0027]
The molten PTT is then sent to spin head 7 set at 250 to 280 ° C. via bends 5 and 6 and separately metered by a gear pump. Thereafter, the two types of components are joined by a spinneret 9 having a plurality of holes attached to the spin pack 8 and bonded side-by-side, and then extruded as a multifilament 10 into a spinning chamber.
The optimum temperature of the extruder and the spin head is selected from the above range according to the limiting viscosity and the shape of the PTT pellet.
The PTT multifilament 10 extruded into the spinning chamber passes through a non-blowing region 11 having a length of 50 to 300 mm, is cooled and solidified to room temperature by a cooling air 12, applies a finishing agent, and rotates at a predetermined speed. After being taken up by the first godet roll 14, without being wound once, and then continuously stretched with a second godet roll (in this drawing, a heated godet roll) 15, after being stretched and heat-treated by the third godet roll 16, It is wound as a composite fiber package 17 having a predetermined fineness by a winder.
[0028]
Before the solidified multifilament 10 comes into contact with the take-off godet roll 14, a finishing agent is applied by the finishing agent applying device 13. A water-based emulsion type is used as the finishing agent to be applied.
The concentration of the aqueous emulsion of the finishing agent is 10% by weight or more, preferably 15 to 30% by weight.
Two or more godet rolls are used. For example, in FIG. 4, a pair of pretension rolls may be provided before the take-off godet rolls.
Between two pairs of godet rolls, stretching is performed 1.2 to 3 times by changing the peripheral speed of the godet rolls.
[0029]
In stretching, the temperature of the first godet roll is 50 to 90 ° C, preferably 55 to 70 ° C. The drawn yarn is subjected to necessary heat treatment by a second godet roll. The temperature of the heat treatment is 80 to 160 ° C, preferably 100 to 140 ° C. Heat treatment is performed in a tension state between the second godet roll and the third godet roll. The third godet roll may be a heated godet roll or may be non-heated. If necessary, a confounding device may be provided before the first godet roll or after the third godet roll to perform confounding.
Alternatively, a two-stage method may be employed in which after the finish is applied, the fiber is once wound as undrawn fiber and drawn by a drawing machine or the like.
[0030]
As the false twist processing of the PTT-based composite fiber of the present invention, generally used processing methods such as a pin type, a friction type, a nip belt type, and an air false twist type are employed. The false twist heater may be either one heater false twist or two heater false twist, but in order to obtain high stretchability, one heater false twist is more preferable. The temperature of the false twist heater is preferably set such that the yarn temperature immediately after the outlet of the first heater is 130 to 200 ° C, preferably 150 to 180 ° C, particularly preferably 160 to 180 ° C.
It is preferable that the stretchable stretch ratio of the false twisted yarn obtained by 1-heater false twisting is 100 to 300%, and the stretchable elastic modulus is 80% or more.
If necessary, the yarn may be heat-set by the second heater to form a two-heater false twisted yarn. The temperature of the second heater is preferably in the range of 100 to 210C, and more preferably in the range of -30C to + 50C with respect to the yarn temperature immediately after the outlet of the first heater.
It is preferable that the overfeed rate (second overfeed rate) in the second heater is + 3% to + 30%.
[0031]
The false-twisted yarn obtained by false-twisting the PTT-based conjugate fiber of the present invention has good quality and an expansion / contraction elongation ratio of crimp that is apparent before the boiling water treatment is 50 to 300%. The large crimp that is apparent before the boiling water treatment is an important requirement to guarantee high crimp development and elongation recovery after the boiling water treatment, that is, stretchability and instant recovery, even in a fabric with a large binding force. .
When the false twisted yarn obtained by false twisting the PTT-based conjugate fiber of the present invention is used as the weft of a woven fabric, the yarn has stretchability even before the greige treatment, that is, before the boiling water treatment. This property was not found at all in known false twisted yarns or composite fibers having latent crimpability.
The obtained false twisted yarn is, for example, 3 × 10^-3It is also a great feature that it exhibits a high crimping property of 30% or more as measured by elongation at stretching measured after boiling water treatment under a load of cN / dtex. It is understood that, when compared with a false twisted yarn obtained by false-twisting a fiber of PTT alone under the same conditions as the stretch-elongation ratio of about 10%, extremely high crimp performance is exhibited. Another characteristic of the false twisted yarn is that the elongation recovery speed after boiling water treatment is 20 to 50 m / sec, which is excellent in instantaneous recovery.
[0032]
The elongation recovery speed means a speed at which the crimped yarn is subjected to boiling water treatment without load, then the crimp is elongated to a certain stress, and then the fiber is cut and the fiber is instantaneously recovered. This measuring method was first devised by the present invention, and was able to quantitatively measure the stretchback property.
The fact that the stretch recovery speed is high expresses a quick stretch recovery property, that is, excellent exercise followability when made into clothes. If the elongation recovery speed is 15 m / sec or more in the knitted fabric structure and 20 m / sec or more in the woven fabric structure, a knitted fabric excellent in followability to movement can be obtained. If the value is less than this value, the ability to follow a movement when formed into a fabric is insufficient. The preferred elongation recovery speed is 20 m / sec or more for knitted fabric applications and 25 m / sec or more for woven fabric applications. On the other hand, those having an elongation recovery speed of more than 50 m / sec are difficult to manufacture with the current state of the art.
[0033]
According to this measurement method, the elongation recovery speed of the known polyethylene terephthalate false twisted yarn is about 10 m / sec, and the false twisted yarn of PTT alone fiber is about 15 m / sec. As is apparent from the fact that the elongation recovery speed of the known spandex elastic fiber is about 30 to 50 m / sec, the false twisted yarn obtained by false twisting the PTT composite fiber of the present invention is a spandex yarn. It will be appreciated that it is comparable to elastic fibers.
The PTT-based conjugate fiber of the present invention can be used for a knitted fabric with or without false twisting. As the structure of the woven fabric, various woven structures derived from them, including a plain woven structure, a twill woven structure, and a satin woven structure, can be applied. In the woven fabric, the PTT-based composite fiber of the present invention can be used for only warp, only weft, or both.
These fabrics have a stretch ratio of at least 10%, preferably 15% or more, more preferably 20% or more. When the stretch rate is 10% or more, the object of the present invention is effectively exhibited because the elastic body follows a local and instantaneous movement displacement instantaneously when used in sports clothing or the like.
[0034]
The recovery rate of the woven fabric is preferably 80 to 100%. More preferably, it is 85 to 100%.
Another feature of the present invention is that the elongation stress when elongating the woven fabric is small. For example, when the stress at 10% elongation is 150 cN / cm or less, the feeling of pressure upon wearing is small, which is preferable. More preferably, it is 50 to 100 cN / cm.
The woven fabric using the PTT-based composite fiber of the present invention is suitable for lining applications. For example, when used as a lining for women's clothing or men's clothing, there is no feeling of pressure when flexing, and an excellent feeling of wearing clothes can be obtained. Further, even if an elongation stress is applied to the garment, excellent durability can be obtained without slippage of a seam or the like.
[0035]
When the PTT-based composite fiber of the present invention is used for a woven fabric, it may be untwisted or may be entangled or twisted for the purpose of enhancing convergence. When twist is applied, twist is applied in the same direction as the false twist direction or in a different direction. In this case, the twist coefficient is preferably set to 5000 or less.
The twist coefficient is represented by the following equation.
Number of twists T (times / m) = twist coefficient k / (fineness of false twisted yarn; dtex)^0.5
The PTT-based composite fiber of the present invention may be used alone, or the effects of the present invention can be exhibited even when used in combination with other fibers. The composite may be used as a long fiber or as a short fiber. As other fibers to be composited, for example, synthetic fibers such as other polyester fibers and nylon, acrylic, cupra, rayon, acetate, polyurethane elastic fibers, and natural fibers such as cotton, hemp, silk, and wool are selected. It is not limited to these. The composite may be a long fiber or a short fiber.
[0036]
In addition, in order to obtain a woven fabric in which a conjugate fiber and another fiber are mixed and mixed, a mixed fiber composite yarn is obtained by interlacing the other fiber, drawing false twist after interlace mixing, and then false twisting only one of the fibers. Interlace blending, interlace blending after false twisting both separately, or interlacing blending after either one can be manufactured by various blending methods such as interlace blending after Taslan blending, Taslan blending after interlace blending, and Taslan blending. The mixed fiber composite yarn obtained by such a method is preferably provided with 10 or more entanglements, preferably 15 to 50 entanglements / m.
[0037]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in more detail with reference to Examples and the like, but needless to say, the present invention is not limited to the Examples and the like.
In addition, the measurement method and measurement conditions of the physical properties performed in the examples will be described.
(1) Intrinsic viscosity
The intrinsic viscosity [η] is a value determined based on the definition of the following equation.
[Η] = lim (ηr-1) / C
C → 0
Ηr in the definition is a value obtained by dividing the viscosity at 35 ° C. of a diluted solution of a PTT polymer dissolved in an o-chlorophenol solvent having a purity of 98% or more by the viscosity of the solvent measured at the same temperature, and the relative viscosity and It is defined. C is the polymer concentration expressed in g / 100 ml.
[0038]
(2) Number of bumpy single yarns
U% is measured at the same time as obtaining a fineness variation chart (Diagram Mass) by the following method.

In a U% chart measured at a full scale of ± 12.5%, a whisker-like single yarn having a whisker-like signal exceeding 5% in the thick decitex direction with respect to the average fineness as a whisker-like single yarn, and having a whisker-like single yarn existing at a measuring yarn length of 1000 m Was measured.
[0039]
(3) Degree of confounding (CF)
Entanglement tester (manufactured by Rothschild): R2072 type was used, and the number of trips of the stylus was measured 30 times at trip levels of 15 cN and 50 cN at a yarn speed of 5 m / min to determine the degree of confounding.
(4) Spinning stability
Using a melt spinning-continuous stretching machine equipped with a spinning end having 8 ends per spindle, melt spinning-continuous stretching was performed for 2 days for each example.
The following judgment was made based on the number of occurrences of yarn breakage during this period and the frequency of occurrence of fluff (the ratio of the number of fluff generating packages) present in the obtained composite fiber package.
◎: Thread breaks 0 times, fluff generation package ratio 5% or less
○: Less than 2 times of yarn breakage, fluff generation package ratio less than 10%
×: Thread breaks 3 times or more, fluff generation package ratio 10% or more
[0040]
(5) False twistability
The false twisting process was performed under the following conditions, and the openability and the false twisting processability were evaluated by the number of yarn breaks per day when the false twisting process was continuously performed at 96 weights / unit.

The number of times the yarn was broken in the heater after the feed roller was determined as follows.
：: Very good with less than 10 yarn breaks / day / unit
：: Good when the number of thread breaks is 10 to 30 times / day / unit
×: The number of thread breaks exceeds 30 times / day / unit, making industrial production difficult
[0041]
(6) Processed yarn quality
Fabric adjustment
Fabrication of the fabric was performed as follows. A plain woven fabric was prepared by using a 56 dtex / 24f PTT single fiber (Asahi Kasei "Solo") non-twisted and glued yarn as the warp, and using the 56 dtex / 24f composite fiber of each of Examples and Comparative Examples of the present invention as the weft. .

The obtained greige was continuously scoured at 95 ° C. with an open soaper, dried in a cylinder at 120 ° C., and then dyed at 120 ° C. with a jet dyeing machine. Next, a series of finishing and tentering heat setting processes were performed at 175 ° C.
[0042]
Fabric evaluation
The obtained woven fabric was inspected by a skilled inspection technician, and the quality of the dyed weft was determined as follows to evaluate the quality of the processed yarn.
◎: No untwisting or nodal defects, extremely good
: Good with few untwisted and nodal defects
×: Many untwisted or nodular defects, poor
(7) Comprehensive evaluation
◎: Very good in spinnability, false twisting stability and woven quality
: Good spinnability, false twisting stability, and woven fabric quality
×: Any of spinnability, false twisting stability, and fabric quality are poor.
[0043]
Examples 1-4, Comparative Example 1
In this example, the effect of the content of the high intrinsic viscosity powder will be described.
As one component, a PTT pellet containing 0.4% by weight of titanium oxide and having an average intrinsic viscosity [η] of 1.30 dl / g was used.
The PTT pellets were extruded by passing powders having an intrinsic viscosity [η] of 1.50 dl / g (1.15 times the average intrinsic viscosity) passing through a 24-mesh filter with different contents as shown in Table 1. Was done. As the other component, a PTT pellet containing 0.4% by weight of titanium oxide and having an average intrinsic viscosity of 0.92 was used.
These were melted by a spinning machine as shown in FIG. 4 using an extruder equipped with a Murdoch-type screw, at an extrusion temperature of 270 ° C. at the time of melting and at a shear rate of 202 (1 / second). It was discharged and spun. The cooled and solidified filament was produced into a 56 dtex / 24 filament PTT composite fiber using a winder having three pairs of godet rolls.
[0044]
The spinning conditions in this example are as follows.

[0045]

The obtained PTT-based composite fiber was false-twisted under the processing conditions described above to obtain a false-twisted yarn. Table 1 shows the spinnability, false twisting property and quality of the false twisted yarn.
As is clear from Table 1, when the powder content of the high intrinsic viscosity is within the range of the present invention, the spinning properties, the false twisting properties, and the quality of the false twisting threads were good.
[0046]
[Table 1]

[0047]
Examples 5 to 7, Comparative Examples 2 to 5
In this embodiment, the effect of the melt extrusion conditions will be described.
In performing melt extrusion using the PTT pellets containing a high intrinsic viscosity powder shown in Example 2, extrusion was performed by changing the screw type, extrusion temperature and shear rate as shown in Table 2.
A false twisted yarn was obtained from the obtained PTT-based composite fiber in the same manner as in Example 1. Table 2 shows the spinnability, false twisting property and quality of the false twisted yarn.
As is clear from Table 2, good spinnability, false twisting property and good quality false twisted yarn were obtained by the melt extrusion conditions of the present invention.
[0048]
[Table 2]

[0049]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to this invention, when a PTT-type composite fiber breaks the yarn break at the time of false twisting, and when the obtained false twisting yarn is used for the warp and / or weft of a lining textile, untwisting and a knot are performed. It is possible to eliminate the shape defect.
Further, according to the present invention, there is provided a PTT-based conjugate fiber capable of exhibiting excellent quality, a soft feel and outstanding stretch properties, and a method for industrially stably producing the same.
[Brief description of the drawings]
FIG. 1 is a schematic view showing an example of a “cob” -shaped single yarn.
FIG. 2 is a schematic diagram illustrating an example of a U% chart of a PTT-based conjugate fiber in which a large number of “cob” -shaped single yarns are present.
FIG. 3 is a schematic diagram showing an example of a U% chart of a PTT-based conjugate fiber in which a “cob” -shaped single yarn does not exist.
FIG. 4 is a schematic view of a composite spinning facility used in the production method of the present invention.
[Explanation of symbols]
1: Polymer chip dryer
2: Extruder
3: Polymer chip dryer
4: Extruder
5: Bend
6: Bend
7: Spin head
8: Spin pack
9: Spinneret
10: Multifilament
11: Non-blast area
12: Cooling air
13: Finishing agent application device
14: 1st godet roll
15: Second godet roll
16: Third godet roll
17: Composite fiber package

Claims (6)

At least one component of the single yarn is polytrimethylene terephthalate, and the other component is composed of a single yarn group in which two polyester components composed of polyester are bonded in a side-by-side type or an eccentric sheath-core type. When the intrinsic viscosity of the polytrimethylene terephthalate is 0.6 to 1.6 dl / g, and the variation in fineness U% (normal method) is measured over a length of 1000 m of the composite fiber, the decitex is an average value. A polytrimethylene terephthalate-based conjugate fiber, wherein the number of beard signals generated by 5% or more is 10 or less. The light confounding degree (CF) is 0 to 50 / m at a measuring strength (trip level) of 15 cN, and 0 to 2 / m at a measuring strength of 50 cN. 1. A polytrimethylene terephthalate-based composite fiber. 3. The polytrimethylene according to claim 1, wherein one component is polytrimethylene terephthalate and the other component is polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate or a copolymer thereof. Terephthalate-based composite fiber. The polytrimethylene terephthalate-based composite fiber according to any one of claims 1 to 3, wherein the number of mustache signals generated is 2 or less per 1000 m of yarn length. A polyester yarn comprising a single yarn group in which two polyester components are bonded in a side-by-side type or an eccentric sheath-core type, and at least one component constituting the single yarn has an average intrinsic viscosity of 0.6 to 1.6. A method for producing a polytrimethylene terephthalate-based composite fiber, wherein the following requirements (A) and (B) are simultaneously satisfied when producing a composite fiber using methylene terephthalate pellets.
(A) having an intrinsic viscosity that is 1.1 times or more higher than the average intrinsic viscosity of the high-viscosity component, and having a content of powder passing through a 24 mesh filter of 2% by weight or less,
(B) Melting is performed at an extrusion temperature of 250 to 280 ° C. and a shear rate of 40 to 200 (1 / second) during melt extrusion. The method for producing a polytrimethylene terephthalate-based composite fiber according to claim 5, wherein a Murdoch screw is used as the melt extrusion screw.

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