JP3919923B2 - Method for producing polyester low shrinkable ultrafine fiber - Google Patents

Description

ただし、Ａ、Ｂ、Ｃは、それぞれ第１ローラ、第２ローラ、第３ローラの温度（℃）、Ｍは、第１ローラと第２ローラ間の延伸倍率、Ｎは、第２ローラと第３ローラ間のリラックス率（％）を示す。
【０００９】
【発明の実施の形態】
以下、本発明について詳細に説明する。
本発明は、溶融紡糸した糸条を第１〜第３ローラで引き取った後、巻き取る３ローラ式のスピンドロー装置を用い、紡糸速度2500ｍ／分以上の高速で行い、かつ各ローラを特定の温度条件を満たすものとし、第１ローラと第２ローラ間で延伸熱処理したものを第２ローラと第３ローラ間でリラックス熱処理することにより低収縮性の極細繊維を得るものである。
【００１０】
本発明においては、３ローラ式のスピンドロー装置を用い、紡糸速度2500ｍ／分以上の高速で行う必要がある。２ローラ方式の装置では、かなりの高温で熱処理する必要があり、繊維の融着や糸切れが生じ、操業性よく製造することができない。また、４ローラ以上のスピンドロー装置では、目的とする低収縮性の極細繊維を得ることはできるが、設備コスト、メンテナンスコストが増加するため好ましくない。
【００１１】
さらに、2500ｍ／分未満の紡糸速度では、生産性が低下するのみならず、繊維同士の密着が生じ、巻き取りが困難となる。紡糸速度の上限は特に限定されるものではないが、3000〜4000ｍ／分程度とすることが好ましい。なお、本発明でいう紡糸速度は、第１ローラの速度である。
【００１２】
そして、本発明においては、溶融紡糸した糸条をまず始めに引き取る第１ローラの温度を７５〜９５℃、第２ローラの温度を１１０〜１３０℃として、第１ローラと第２ローラの間で１．３５〜１．５０倍の延伸を施す。
【００１３】
第１ローラの温度が７５℃未満では、延伸時の熱量が不足し、得られる繊維は延伸斑が生じ、染色斑の原因となる。一方、９５℃を超えると単糸切れが生じ、得られる繊維は毛羽が生じる。
第２ローラ温度が１１０℃未満であると、第２ローラでの熱処理が不十分となるため、第３ローラで熱処理しても沸水収縮率を2.0 ％以下とすることができず、一方、１３０℃を超えると、収縮率が下がりすぎ、第２ローラと第３ローラ間でのリラックス熱処理が十分に行われないために、沸水収縮率を2.0 ％以下とすることができない。
【００１４】
第１ローラと第２ローラ間で施す延伸の倍率が１．３５未満では、得られる極細繊維の沸水収縮率が2.0 ％を超え、１. ５０を超えると単糸切れが生じ、得られる繊維は毛羽が生じたものとなる。
【００１５】
そして、第３ローラ温度を１４０〜１８０℃とし、第２ローラと第３ローラ間でリラックス率３〜８％でリラックス熱処理を行う。
第３ローラ温度が１４０℃未満では、熱量が不十分であり、得られる極細繊維の沸水収縮率が2.0 ％を超え、１８０℃を超えると繊維の融着や糸切れが生じ、操業性が悪化する。
【００１６】
そして、第２ローラと第３ローラ間のリラックス率が３％未満では、得られる極細繊維の沸水収縮率が2.0 ％を超え、目的とする低収縮性極細繊維が得られず、８％を超えるとローラ上での糸揺れが大きくなり、ローラ巻き付き等により糸切れが多発し、巻き取りが困難になる。
【００１７】
本発明においては、熱処理効果を上げ、糸のローラ上でのスリップ防止、糸揺れ防止の点から、各ローラに複数回ラップするのが好ましい。
【００１８】
本発明は、以上のような方法により、製編織すればソフト感に優れた織編物となる、沸水収縮率0.5 〜2.0 ％、単糸繊度１ｄ以下、トータル繊度30〜130 ｄの低収縮性極細繊維を得ることができるものである。
【００１９】
極細繊維の沸水収縮率が0.5 ％未満であると、ソフト感に優れた織編物を得ることができるが、沸水収縮率を下げるためにより高温で熱処理したり、リラックス率を大きくする必要があり、安定した生産が困難になる。また、2.0 ％を超えると熱処理による収縮が大きくなり、この繊維よりなる布帛はソフト感に劣るものとなる。
【００２０】
また、単糸繊度が１ｄを超えると、製編織した布帛はソフト感に劣るものとなる。単糸繊度の下限は特に限定されるものではないが、0.3 ｄ程度とすることが好ましい。
【００２１】
さらにトータル繊度が30ｄ未満であると、種々の工程通過時に糸切れなどが多発し、130 ｄを超えると高速スピンドロー法により製造する際に、延伸斑が発生する。
【００２２】
本発明におけるポリエステルとは、主にエチレンテレフタレート単位を主たる繰り返し単位とするポリエステルをいうが、その性質を本質的に変えない範囲で、第３成分として、例えば、イソフタル酸、５−ナトリウムスルホイソフタル酸等のジカルボン酸、プロピレングリコール、1,4 −ブタンジオール、ジエチレングリコール、ポリエチレングリコール等のジオール類を共重合したコポリエステルでもよく、また、これらのポリエステルに艶消し剤、安定剤、着色剤、難燃剤、表面改質剤等を添加したものでもよい。
【００２３】
また、極細繊維は、単一成分のポリエステルで構成しても、複数成分のポリエステルを用いて、サイドバイサイド構造や芯鞘構造等のものとしてもよく、断面形状は、丸断面に限定されず、三角断面等の異形断面や中空断面でもよい。
【００２４】
【実施例】
次に、本発明を実施例により具体的に説明する。
なお、実施例における物性値の測定や評価は次のように行った。
１．沸水収縮率（１００Ｗ）
得られた繊維に１００ｍｇ／ｄの荷重をかけて、試料長Ｌ₀ を測定した後、試料を無荷重の状態で３０分間沸水処理し、再び１００ｍｇ／ｄの荷重をかけて試料長Ｌ₁ を測定し、次式で算出した。
１００Ｗ（％）＝〔（Ｌ₀ −Ｌ₁ ）／Ｌ₀ 〕×１００ ２．強伸度
島津製作所社製オートグラフＡＧＳ１００Ｇを用い、試料長４０ｃｍ、引張速度５０ｃｍ／分で測定した。
３．布帛の風合
得られた繊維を300 Ｔ／ｍに加撚し、糊付け（３０℃）、乾燥（８５℃）して整経した後、製織し（織密度：経110 本／2.54cm、緯78本／2.54cm）、97℃の熱水でリラックス精練し、160 ℃で仕上げ熱処理を施して平織物を得た。
この織物の柔軟性を手触りで５段階評価し、最も柔軟性に優れているものを５とした。
４．ウースター斑
ＺＥＬＬＷＥＧＥＲ ＵＳＴＥＲ社のＵＳＴＥＲ ＴＥＳＴＥＲ ＵＴ−１を使用し、糸速度２５ｍ／分、チャート速度５ｃｍ／分で測定し、２％未満を◎、２〜３％未満を○、３〜４％未満を△、４％以上を×とした。
５．毛羽
目視にてパッケージの外観検査を行い、表面の毛羽数が０個を◎、１〜３個を○、４〜６個を△、７個以上を×とした。
【００２５】
実施例１
極限粘度（フェノールと四塩化エタンとの等重量混合物を溶媒として、20℃で測定した）0.68のＰＥＴを305 ℃で溶融し、24.3ｇ／分の吐出量で紡糸口金（168 孔）を用いて紡糸し、第１ローラ（88℃、速度3200ｍ／分（紡糸速度））に7.5 回ラップした後、第２ローラ（120 ℃、速度4600ｍ／分）に7.5 回ラップし、第１ローラと第２ローラ間で1.437 倍の延伸を施した。続いて、第３ローラ（170 ℃、速度4370ｍ／分）に7.5 回ラップし、第２ローラと第３ローラ間で５％のリラックス熱処理を施し、4380ｍ／分で巻き取った。
トータル繊度50.0ｄ、単糸繊度0.30ｄ、強度4.42ｇ／ｄ、伸度42.1％、100W 1.2％、ウースター斑評価が◎の低収縮性極細繊維を得た。
パッケージの外観、得られた繊維を製織した布帛の風合の評価結果を表１に示す。
【００２６】
実施例２〜１１、比較例１〜１０
第１〜第３ローラの温度、第１ローラと第２ローラ間での延伸倍率、および第２ローラと第３ローラ間でのリラックス率を表１に示すように種々変更した以外は、実施例１と同様に行い、低収縮性極細繊維を得た。
得られた繊維のトータル繊度、単糸繊度、強度、伸度、100W、ウースター斑評価及びパッケージの外観、繊維を製織した布帛の評価結果を表１に示す。
【００２７】
実施例12
吐出量を48.6ｇ／分に変更した以外は、実施例１と同様に行い、低収縮性極細繊維を得た。
得られた繊維のトータル繊度、単糸繊度、強度、伸度、100W、ウースター斑評価及びパッケージの外観、繊維を製織した布帛の評価結果を表１に示す。
【００２８】
実施例13
吐出量を58.3ｇ／分に変更し、紡糸孔が300 個の紡糸口金より紡糸した以外は、実施例１と同様に行い、低収縮性極細繊維を得た。
得られた繊維のトータル繊度、単糸繊度、強度、伸度、100W、ウースター斑評価及びパッケージの外観、繊維を製織した布帛の評価結果を表１に示す。
【００２９】
比較例11
紡糸孔が48個の紡糸口金より紡糸した以外は、実施例１と同様に行い、低収縮性極細繊維を得た。
得られた繊維のトータル繊度、単糸繊度、強度、伸度、100W、ウースター斑評価及びパッケージの外観、繊維を製織した布帛の評価結果を表１に示す。
【００３０】
【表１】

【００３１】
表１より明らかなように、実施例１〜13では、低収縮性で斑のない極細繊維を一工程法により操業性よく生産することができ、これらの極細繊維からなる布帛は、柔軟性に優れた風合を有するものであった。
一方、比較例１は、第１ローラの温度が低かったため、得られた繊維は延伸斑が生じた。比較例２は、第１ローラの温度が高すぎたため、得られた繊維は延伸斑と毛羽が生じた。比較例３は、第２ローラの温度が低かったため、比較例４は第２ローラの温度が高かったため、比較例５は第３ローラの温度が低かったため、得られた繊維は、沸水収縮率が2.0 ％を超えるものであった。比較例６は、第３ローラの温度が高かったため、ローラ上で繊維が焦げつき、糸切れが多発して巻き取れなかった。比較例７は、第１ローラと第２ローラ間での延伸倍率が低すぎたため、得られた繊維は、沸水収縮率が2.0 ％を超えるものであった。比較例８は、第１ローラと第２ローラ間での延伸倍率が高すぎたため、得られた繊維は、毛羽が生じた。比較例９は、第２ローラと第３ローラ間でのリラックス率が低すぎたため、得られた繊維の沸水収縮率が2.0 ％を超えるものであった。比較例１０は、第２ローラと第３ローラ間でのリラックス率が高すぎたため、ローラ上での糸揺れが大きく、巻き付きにより糸切れが多発して巻き取れなかった。そして、比較例１〜５、７〜９で得られた繊維からなる布帛は、柔軟性に劣るものであった。比較例１１は、得られた繊維の単糸繊度が１ｄを超えるものであったため、この繊維からなる布帛は、柔軟性に劣るものであった。
【００３２】
【発明の効果】
本発明によれば、沸水収縮率の低い、低収縮性極細繊維を操業性よく生産することができ、この繊維を製編織すれば、獣毛調のソフトな風合に優れた布帛を得ることが可能となる。[0001]
BACKGROUND OF THE INVENTION
TECHNICAL FIELD The present invention relates to a method for producing a polyester low-shrinkable ultrafine fiber capable of obtaining a woven or knitted fabric having a soft texture with a soft feeling.
[0002]
[Prior art]
Polyester microfibers made of polyethylene terephthalate (PET) and having a single yarn fineness of 1 denier or less are suitably used for animal hair-like woven or knitted fabrics that are rich in soft feeling and drape.
In recent years, as the texture required for woven and knitted fabrics has diversified, there has been a demand for woven and knitted fabrics with a softer feel. It is requested.
[0003]
As a method of producing low-shrinking ultrafine fibers, a method of relaxing heat treatment of a yarn produced by a normal high-speed spinning method (POY method) and a method of heat-treating at a high temperature in a spin draw method (SDY method) are adopted. .
[0004]
However, in the former case, in order to obtain ultrafine fibers having a low boiling water shrinkage, it is necessary to heat treat the fibers obtained by the POY method at a high temperature of 200 ° C. or higher with a relaxation rate of nearly 10%. Heat treatment under such conditions of high temperature and high relaxation rate causes many broken yarns, stable production cannot be achieved, and boiling water shrinkage rate is sufficiently low (boiling water shrinkage rate 2.0% or less), and ultrafine fibers cannot be obtained. It was.
[0005]
Also in the latter case, by setting the heat treatment roller temperature to 200 ° C. or higher, it is possible to obtain ultrafine fibers having a boiling water shrinkage of about 3.0%, but obtaining low shrinkage ultrafine fibers having a boiling water shrinkage of 2.0% or less. I couldn't.
[0006]
There is a strong demand to produce such ultra-shrinkable fibers with a boiling water shrinkage of 2.0% or less in a one-step method from the viewpoint of simplifying the production process and reducing production costs, but a production method that is still satisfactory is proposed. It has not been.
[0007]
[Problems to be solved by the invention]
The present invention solves the above-mentioned problems, and can produce ultrafine fibers having a boiling water shrinkage of 2.0% or less, which becomes a woven or knitted fabric excellent in soft feeling when knitted or woven, with good operability and low cost by a one-step method. It is a technical problem to provide a manufacturing method that can be used.
[0008]
[Means for Solving the Problems]
The inventors of the present invention have reached the present invention as a result of intensive studies in order to solve the above problems.
That is, the present invention uses a three-roll type spin draw device that takes up the melt-spun yarn with the first to third rollers and then winds it up, using a spinning speed of 2500 m / min or more, and a single yarn fineness of 1 d or less. Polyester low characterized by satisfying the conditions of the following formulas (1) to (6) when producing a low shrinkable polyester ultrafine fiber having a fineness of 30 to 130 d and a boiling water shrinkage of 0.5 to 2.0% The gist of the manufacturing method of the shrinkable ultrafine fiber.

Where A, B, and C are the temperatures (° C.) of the first roller, the second roller, and the third roller, respectively, M is the draw ratio between the first roller and the second roller, and N is the second roller and the second roller. The relaxation rate (%) between 3 rollers is shown.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail.
In the present invention, a melt-spun yarn is taken up by the first to third rollers and then wound up, and then a three-roll type spin draw device is used, and the spinning speed is 2500 m / min or more. It is assumed that the temperature condition is satisfied, and a low heat-shrinkable ultrafine fiber is obtained by relaxing heat treatment between the first roller and the second roller and relaxing heat treatment between the second roller and the third roller.
[0010]
In the present invention, it is necessary to use a three-roller type spin draw apparatus at a spinning speed of 2500 m / min or more. In the two-roller type apparatus, it is necessary to perform heat treatment at a considerably high temperature, fiber fusion or thread breakage occurs, and it cannot be manufactured with good operability. In addition, in a spin draw apparatus having four or more rollers, the desired low-shrinkable ultrafine fiber can be obtained, but it is not preferable because the equipment cost and the maintenance cost increase.
[0011]
Furthermore, when the spinning speed is less than 2500 m / min, not only the productivity is lowered, but also the fibers are brought into close contact with each other and winding becomes difficult. The upper limit of the spinning speed is not particularly limited, but is preferably about 3000 to 4000 m / min. The spinning speed referred to in the present invention is the speed of the first roller.
[0012]
In the present invention, first, the temperature of the first roller for picking up the melt-spun yarn is 75 to 95 ° C., and the temperature of the second roller is 110 to 130 ° C. between the first roller and the second roller. 1.35 to 1.50 times stretching is applied.
[0013]
When the temperature of the first roller is less than 75 ° C., the amount of heat at the time of stretching is insufficient, and the resulting fiber has stretch spots and causes stain spots. On the other hand, when the temperature exceeds 95 ° C., single yarn breakage occurs, and the resulting fiber has fluff.
When the temperature of the second roller is less than 110 ° C., the heat treatment with the second roller becomes insufficient, so that the boiling water shrinkage rate cannot be reduced to 2.0% or less even with the heat treatment with the third roller. If it exceeds ° C., the shrinkage rate is too low, and the relaxation heat treatment between the second roller and the third roller is not sufficiently performed, so that the boiling water shrinkage rate cannot be made 2.0% or less.
[0014]
When the draw ratio applied between the first roller and the second roller is less than 1.35, the boiling water shrinkage of the resulting ultrafine fiber exceeds 2.0%, and when it exceeds 1.50, single yarn breakage occurs, Fluff is produced.
[0015]
Then, the third roller temperature is set to 140 to 180 ° C., and the relaxation heat treatment is performed between the second roller and the third roller at a relaxation rate of 3 to 8%.
If the temperature of the third roller is less than 140 ° C, the amount of heat is insufficient, and the boiling water shrinkage of the resulting ultrafine fiber exceeds 2.0%, and if it exceeds 180 ° C, fiber fusion or yarn breakage occurs, resulting in poor operability. To do.
[0016]
If the relaxation rate between the second roller and the third roller is less than 3%, the boiling water shrinkage of the resulting ultrafine fiber exceeds 2.0%, and the desired low-shrinkable ultrafine fiber cannot be obtained, exceeding 8%. As a result, the yarn swaying on the roller becomes large, and thread breakage occurs frequently due to winding of the roller, making winding difficult.
[0017]
In the present invention, it is preferable to wrap each roller a plurality of times from the viewpoint of increasing the heat treatment effect and preventing slippage of the yarn on the roller and prevention of yarn swinging.
[0018]
The present invention provides a woven or knitted fabric excellent in soft feeling when knitted and woven by the above-described method. Boiling water shrinkage 0.5 to 2.0%, single yarn fineness 1d or less, total shrinkage 30 to 130d, low shrinkage ultrafine A fiber can be obtained.
[0019]
When the boiling water shrinkage of the ultrafine fibers is less than 0.5%, a woven or knitted fabric with excellent soft feeling can be obtained, but it is necessary to heat-treat at a higher temperature or increase the relaxation rate to lower the boiling water shrinkage, Stable production becomes difficult. On the other hand, if it exceeds 2.0%, shrinkage due to heat treatment increases, and the fabric made of this fiber is inferior in soft feeling.
[0020]
On the other hand, when the single yarn fineness exceeds 1d, the woven and knitted fabric is inferior in soft feeling. The lower limit of the single yarn fineness is not particularly limited, but is preferably about 0.3 d.
[0021]
Further, when the total fineness is less than 30 d, yarn breakage occurs frequently when passing through various processes, and when it exceeds 130 d, stretch spots occur during production by the high-speed spin draw method.
[0022]
The polyester in the present invention refers to a polyester mainly composed of ethylene terephthalate units as a main repeating unit. However, as the third component, for example, isophthalic acid, 5-sodium sulfoisophthalic acid, as long as the properties are not essentially changed. Copolyesters obtained by copolymerizing diols such as dicarboxylic acids such as propylene glycol, 1,4-butanediol, diethylene glycol, and polyethylene glycol may also be used, and matting agents, stabilizers, colorants, and flame retardants for these polyesters. Further, a material to which a surface modifier or the like is added may be used.
[0023]
Further, the ultrafine fiber may be composed of a single component polyester or a multicomponent polyester, and may have a side-by-side structure, a core-sheath structure, or the like. It may be an irregular cross section such as a cross section or a hollow cross section.
[0024]
【Example】
Next, the present invention will be specifically described with reference to examples.
In addition, the measurement and evaluation of the physical property values in the examples were performed as follows.
1. Boiling water shrinkage (100W)
After applying a load of 100 mg / d to the obtained fiber and measuring the sample length L ₀ , the sample was treated with boiling water for 30 minutes in an unloaded state, and again the sample length L ₁ was applied by applying a load of 100 mg / d. Measured and calculated by the following formula.
100 W (%) = [(L ₀ −L ₁ ) / L ₀ ] × 100 Using an autograph AGS100G manufactured by Shimadzu Corporation, the sample length was 40 cm and the tensile speed was 50 cm / min.
3. The fibers obtained by the texture of the fabric are twisted to 300 T / m, glued (30 ° C.), dried (85 ° C.) and warped, and then woven (woven density: warp 110 warps / 2.54 cm, weft 78 pieces / 2.54 cm), relaxed and scoured with hot water at 97 ° C, and finished with heat treatment at 160 ° C to obtain a plain fabric.
The flexibility of this fabric was evaluated by touch on a five-point scale, with 5 being the most flexible.
4). Use Wooster spotter ZELLWEGER USTER's USTER TESTER UT-1, measured at a yarn speed of 25 m / min and a chart speed of 5 cm / min, less than 2% ◎, less than 2-3% ○, less than 3-4% Δ, 4% or more was marked as x.
5. The appearance of the package was visually inspected, and the number of fluffs on the surface was 0, 1 to 3 was ◯, 4 to 6 was Δ, and 7 or more were X.
[0025]
Example 1
Intrinsic viscosity (measured at 20 ° C using an equal-weight mixture of phenol and ethane tetrachloride as a solvent) 0.68 PET was melted at 305 ° C and discharged using a spinneret (168 holes) at a discharge rate of 24.3 g / min. Spin and wrap 7.5 times on the first roller (88 ° C, speed 3200m / min (spinning speed)), then wrap 7.5 times on the second roller (120 ° C, speed 4600m / min). The roller was stretched 1.437 times. Subsequently, it was wrapped 7.5 times on a third roller (170 ° C., speed 4370 m / min), subjected to a 5% relaxation heat treatment between the second roller and the third roller, and wound at 4380 m / min.
A low-shrinkable ultrafine fiber having a total fineness of 50.0d, single yarn fineness of 0.30d, strength of 4.42g / d, elongation of 42.1%, 100W of 1.2%, and Wooster spot evaluation of ◎ was obtained.
Table 1 shows the appearance of the package and the evaluation results of the texture of the fabric woven from the obtained fibers.
[0026]
Examples 2-11, Comparative Examples 1-10
Example 1 except that the temperature of the first to third rollers, the stretch ratio between the first roller and the second roller, and the relaxation rate between the second roller and the third roller were variously changed as shown in Table 1. 1 was performed to obtain a low-shrinking ultrafine fiber.
Table 1 shows the total fineness, single yarn fineness, strength, elongation, 100 W, Worcester spot evaluation, appearance of the package, and evaluation results of the fabric woven with the fibers.
[0027]
Example 12
Except having changed the discharge amount to 48.6 g / min, it carried out similarly to Example 1 and obtained the low shrinkable ultrafine fiber.
Table 1 shows the total fineness, single yarn fineness, strength, elongation, 100 W, Worcester spot evaluation, appearance of the package, and evaluation results of the fabric woven with the fibers.
[0028]
Example 13
A low-shrinkable ultrafine fiber was obtained in the same manner as in Example 1 except that the discharge rate was changed to 58.3 g / min and spinning was performed from a spinneret having 300 spinning holes.
Table 1 shows the total fineness, single yarn fineness, strength, elongation, 100 W, Worcester spot evaluation, appearance of the package, and evaluation results of the fabric woven with the fibers.
[0029]
Comparative Example 11
A low-shrinkable ultrafine fiber was obtained in the same manner as in Example 1 except that spinning was performed from a spinneret having 48 spinning holes.
Table 1 shows the total fineness, single yarn fineness, strength, elongation, 100 W, Worcester spot evaluation, appearance of the package, and evaluation results of the fabric woven with the fibers.
[0030]
[Table 1]

[0031]
As is apparent from Table 1, in Examples 1 to 13, ultrafine fibers having low shrinkage and no spots can be produced with good operability by a one-step method, and the fabric made of these ultrafine fibers is flexible. It had an excellent texture.
On the other hand, in Comparative Example 1, since the temperature of the first roller was low, the obtained fiber had stretch spots. In Comparative Example 2, since the temperature of the first roller was too high, the obtained fiber had stretch spots and fluff. In Comparative Example 3, the temperature of the second roller was low. Therefore, in Comparative Example 4, the temperature of the second roller was high. Therefore, in Comparative Example 5, the temperature of the third roller was low. It was over 2.0%. In Comparative Example 6, since the temperature of the third roller was high, the fiber was burned on the roller, yarn breakage occurred frequently, and could not be wound. In Comparative Example 7, since the draw ratio between the first roller and the second roller was too low, the obtained fiber had a boiling water shrinkage rate exceeding 2.0%. In Comparative Example 8, since the draw ratio between the first roller and the second roller was too high, the obtained fiber was fuzzy. In Comparative Example 9, since the relaxation rate between the second roller and the third roller was too low, the boiling water shrinkage rate of the obtained fiber exceeded 2.0%. In Comparative Example 10, since the relaxation rate between the second roller and the third roller was too high, the yarn swayed on the roller was large, and many yarn breaks occurred due to wrapping, and could not be wound. And the fabric which consists of a fiber obtained by Comparative Examples 1-5 and 7-9 was inferior to a softness | flexibility. In Comparative Example 11, since the single yarn fineness of the obtained fiber exceeded 1d, the fabric made of this fiber was inferior in flexibility.
[0032]
【The invention's effect】
According to the present invention, low shrinkage ultrafine fibers having a low boiling water shrinkage ratio can be produced with good operability, and if these fibers are knitted or woven, a fabric excellent in soft texture of animal hair can be obtained. Is possible.

Claims (1)

The melt-spun yarn is taken up by the first to third rollers, and then wound using a three-roll type spin draw device, the spinning speed is 2500 m / min or more, the single yarn fineness is 1 d or less, the total fineness is 30 to 130 d, Production of low-shrinkage polyester ultrafine fiber having a boiling water shrinkage of 0.5 to 2.0%, which satisfies the conditions of the following formulas (1) to (6): Method.

Where A, B, and C are the temperatures (° C.) of the first roller, the second roller, and the third roller, respectively, M is the draw ratio between the first roller and the second roller, and N is the second roller and the second roller. The relaxation rate (%) between 3 rollers is shown.