JPH07292516A - Polyester sheath-core conjugate fiber and method for producing the same - Google Patents

Abstract

PURPOSE:To obtain a polyester sheath-core conjugate fiber exhibiting a multicolor expression effect comprising different color tones and different color concentrations. CONSTITUTION:A method for producing the polyester sheath-core conjugate fiber comprises semi-drawing an undrawn conjugate fiber comprising two kinds of polyesters having different dyeabilities as the sheath component and the core component, respectively, to form thick and thin parts in the conjugate fiber in the longitudinal direction, subjecting the semi-drawn conjugate fiber to an alkali weight-reducing treatment to decompose and remove at least the sheath component at the thick parts of the fiber to expose the core parts, or further dyeing the exposed parts and the other parts into different colors.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a polyester sheath core composite fiber and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, as a means for expressing multicolors of textile products, cotton-like dyeing is performed, and fibers having different hues and concentrations are mixed by blending cotton or blended spinning, or yarn-dyed ones are mixed and twisted. , Mixed weaving, mixed knitting, or mixed with spun yarn and fibers with different dyeability before dyeing to create multicolored expressions such as cine, melange, chambre, stonewashing, bleaching, etc. It is obtained by special processing such as fibrillation or ring dyeing of only the fiber surface layer, which is partially decolorized on the surface by physical or chemical treatment. There are problems that it is complicated, the cost is high, and the processing lot is large.

Further, there is a thick and thin fiber which gives a marbling effect as a means for making the fiber itself multicolored. As such a thick and thin fiber, a sheath core composite fiber having a large and thin size obtained by spinning a sheath core composite fiber with two components having different dyeing properties, and stretching this under conditions giving a large thickness is disclosed in JP-A-55-116812. Are known. However, the conventionally known thick and thin composite fibers have a dyeing property mainly dependent on the dyeing property of the polymer in the thick part and the sheath part of the detail, and although the marbling effect due to the dyeing density is obtained, they lack the variety. It was a thing.

[0004]

DISCLOSURE OF THE INVENTION In the present invention, as a result of studying thick and thin sheath core composite fibers, a polyester sheath core composite fiber exhibiting a variety of multicolor expression effects which has never been known has been found. Therefore, an object of the present invention is to provide a polyester sheath core conjugate fiber having a multicolor expression effect of different hues and different concentrations.

[0005]

The present invention is a composite fiber in which one of two kinds of polyesters having different dyeing properties is arranged in a sheath portion and the other is arranged in a core portion. , And at least a part of the core portion of the thick portion is exposed polyester sheath core composite fiber,
And, unstretched composite fibers having one of two polyesters having different dyeing properties as a sheath component and the other as a core component are semi-stretched to form a thin fiber in the fiber axis direction, and then alkali weight reduction treatment is performed. And a sheath component of at least a thick part of the fiber is decomposed and removed.

In the sheath core conjugate fiber of the present invention, preferably, a modified polyester having different dyeability is used in the sheath portion,
Polyester sheath core composite, which is a composite fiber in which unmodified polyester is arranged in the core part, has a thickness in the fiber axis direction, and at least a part of the core part of the thick part is exposed A fiber, preferably, a modified polyester having a different dyeability as a sheath component, and an unstretched composite fiber having an unmodified polyester as a core component is semi-stretched to form a thin fiber in the fiber axial direction, and then an alkali It is manufactured by decomposing and removing the sheath component of at least the thick part of the fiber by weight reduction treatment.

2 constituting the sheath core composite fiber of the present invention
One type of polyester has different dyeability, one is a modified polyester that is dyeable to cationic dyes and acid dyes or is easily dyed to disperse dyes, and the other is non-dyeable to cationic dyes and acid dyes. A typical polyester is an unmodified polyester having a property of being non-easy to disperse dyes. The modified polyester is
Dyeable or easily dyeable polyester containing ethylene terephthalate as a main repeating unit and unmodified polyester is a polyester containing ethylene terephthalate or butylene terephthalate as a main repeating unit. As the modified polyester, cationic polyester dyeable or acid dye dyeable or disperse dye easily dyeable modified polyester is used, and the modified polyester is unmodified on the sheath part from the viewpoint of ensuring strength and easily providing multicolor expression. It is preferable that the polyester is arranged in the core portion.

As the cationic dye dyeable modified polyester, ethylene terephthalate obtained by a known method is copolymerized with an acid group-containing ester forming compound such as a metal salt sulfonate group such as sodium sulfoisophthalic acid and sodium sulfonaphthalenedicarboxylic acid. The modified polyester, preferably a modified polyester obtained by copolymerizing ethylene terephthalate with 1.5 to 3.5 mol% of 5-sodium sulfoisophthalic acid is used.

As the acid dye dyeable modified polyester, ethylene terephthalate obtained by a known method is used together with an amino alcohol such as N-alkyl-substituted diethanolamine and a base-containing ester-forming compound such as tertiary amino-containing glycol. Polymerized modified polyester, modified polyethylene terephthalate with a homopolymer or copolymer of vinyl pyridine is used.

Further, as the disperse dye easily dyeable modified polyester, a modified polyester obtained by copolymerizing ethylene terephthalate obtained by a known method with an ester-forming compound such as isophthalic acid, adipic acid or polyoxyalkylene glycol is used.

Examples of the unmodified polyester include polyethylene terephthalate and polybutylene terephthalate. The unmodified polyester may contain less than 5 mol% of a copolymerization component or a blending component, but polyethylene terephthalate is particularly preferable. Is used.

The composite ratio of the sheath portion and the core portion in the fiber cross section of the sheath core conjugate fiber is preferably 1/3 to 1/1 in terms of the area ratio of the sheath portion / core portion. When the thickness of the sheath portion is too small, the coloring with the dye is dimmed, and when the thickness is too large, it is difficult to obtain thick and thin, and it becomes difficult to secure the strength when the core portion is exposed.

The cross-sectional shape of the sheath core conjugate fiber of the present invention may be any of a round cross section, a triangular cross section, a multilobe cross section, and an irregular cross section, and the shape, number and position of the core are not particularly limited. Not done. The sheath core conjugate fiber of the present invention has a thickness called so-called thick and thin in which the fineness is changed in the fiber axis direction, and at least the whole or a part of the core portion of the thick sheath core conjugate fiber. Is exposed. From the viewpoint of multicolor expression, it is preferable to expose a part of the thick core portion rather than to expose the entire thick core portion, but the degree of exposure of the thick core portion is appropriately selected according to the purpose. Further, the core portion other than the thick portion may be exposed if necessary, but it is preferable to limit the exposure to a part of the core portion other than the thick portion.

Further, in the sheath core composite fiber of the present invention, the sheath portion and the exposed core portion and the thick portion and the detail may be colored in different colors, respectively, and the coloring constitutes the sheath portion and the core portion, respectively. On the basis of the dyeing property of the polyester and the thickening property of the thick part, it is expressed in multiple colors by combining any hue and shade of a cationic dye and a disperse dye, an acid dye and a disperse dye, or a disperse dye and a disperse dye. For example, in dyeing, the sheath part is colored with a cationic dye, the thick part is colored with a darker color with a cationic dye, and the exposed core part of the thick part is colored with a disperse dye in a different hue from the cationic dye, or with only a cationic dye. Provides various coloring effects such as leaving the exposed core area white.

The polyester sheath core conjugate fiber of the present invention is preferably produced as follows. The polyester used in the present invention is a modified or unmodified polyester having different dyeability from each other, and the modified polyester is used as a sheath component and the modified polyester is used as a core component. A dyeable or disperse dye easily modified polyester is used as a sheath component, and an unmodified polyester is used as a core component.

Using the modified and unmodified polyesters as the sheath component and the core component, respectively, and spinning at a predetermined composite ratio by a known sheath core composite spinning method, an unstretched composite fiber having a sheath core composite structure is used. Need to be fine fibers. The unstretched conjugate fiber used has a spinning speed of 1500 to 250 in order to form a good thickness difference.
The unstretched conjugate fiber obtained at 0 m / min is preferable.

In order to obtain thick and thin fibers, the unstretched composite fiber is semi-stretched at a stretch ratio of about half the maximum draw ratio of the fiber, preferably 0.45 to 0.60 times the maximum draw ratio.
Preferably, the stretching is divided into two stages and the two stages are stretched to form thick and thin fibers in the fiber axis direction. The degree of dispersion of the thick portion, the length of the thick portion, and the size of the thick portion in the thick and thin formation are adjusted by setting an appropriate combination of the first stretching and the second stretching in the two-stage stretching.

Preferred embodiments for producing the thick and thin fibers used in the present invention are listed below. The main repeating unit is ethylene terephthalate, a modified polyester obtained by copolymerizing 1.5-3.5 mol% of 5-sodium sulfoisophthalic acid is placed in the sheath part, and polyethylene terephthalate is placed in the core part, and the spinning speed is 1500-500. An unstretched composite fiber obtained by spinning at 2500 m / min was used under the following conditions (1) to (4)
Stretch.

(1) TDR = MDR × (0.45-0.
60) = DR ₁ × DR ₂ (2) DR ₁ = MDR × (0.40 to 0.55) (3) HRT ≦ Tc (4) Tg ≦ HPT ≦ Tc where TDR is the total draw ratio and MDR is the maximum. Draw ratio, D
R ₁ is the first draw ratio, DR ₂ is the second draw ratio, HRT is the first draw temperature, HPT is the second draw temperature, Tc is the crystallization temperature, Tg is the glass transition temperature, and each temperature is in ° C. is there.

The thick and thin conjugate fiber may be in any yarn form such as spun yarn, multifilament yarn or further false twisted yarn. In the present invention, the thick and thin composite fibers, it is also possible to alkali weight reduction treatment in the form of yarn, but after weaving, knitting, woven polyester fiber in the form of a woven fabric or knit,
It is preferable to carry out the alkali weight reduction treatment by the weight reduction processing usually applied to knitted fabrics.

Prior to the alkali weight loss treatment, a raising treatment can be applied. Not only a raising effect is imparted by raising treatment such as paper raising, thistle raising, and needle cloth raising, but also damage to the sheath portion of the surface of the thick and thin composite fibers. The addition promotes the decomposition and removal of the thick portion and the sheath portion of the detail by the alkali in the alkali weight reduction treatment, so that the multicolor expression is further improved.

For the alkali weight reduction treatment, known methods and conditions using an alkali metal hydroxide such as sodium hydroxide are applied, and any method such as suspension weight loss, liquid flow weight loss, pad weight loss is used. In the present invention, the alkali weight reduction treatment decomposes and removes at least the sheath component of the thick composite fiber. When the sheath component is decomposed and removed by the alkali weight reduction treatment, at least the sheath component in the thick portion is decomposed and removed so that at least a part of the core portion in the thick portion is exposed. This alkali reduction treatment needs to be performed within a range in which all the sheath components are not decomposed and removed.

In the alkali weight reduction treatment, the sheath component in the thick portion can be selectively removed to expose the core portion, and at a weight loss rate of 15 to 50 wt%, the ratio of the portion having different dyeability on the fiber surface can be arbitrarily set. Can be changed to.

The thick and thin composite fiber treated with alkali is subjected to a coloring treatment with a cationic dye or an acid dye and / or a disperse dye according to the dyeing properties of the polyester as the sheath component and the core component, and the sheath portion, exposed core portion and The thick part and the details are colored differently. In addition, it is possible to perform various colorings such as leaving the exposed core portion dyed in one-side dyeing such as leaving white, and in some cases, uniformly dyeing the whole.

As a coloring method, known methods and devices such as dyeing, printing or a combination of dyeing and printing, and discharge printing and printing in printing are applied according to the form of the fiber, and are not particularly limited. Absent.

[0026]

EXAMPLES The present invention will be specifically described below with reference to examples.

(Example 1) A cationic dye dyeable modified polyethylene terephthalate prepared by copolymerizing 3.5 mol% of 5-sodium sulfoisophthalic acid was used as a sheath component, and polyethylene terephthalate was used as a core component. Semi-dal 100d / 48f with short thick parts and high dispersion obtained by spinning and semi-drawing into a round cross section with core component = 1/2
The thick and thin composite fiber multifilament yarn of was woven under the following conditions and subjected to alkali weight reduction treatment and coloring treatment.

Woven warp yarn: Semi-dull 100d / 48f, 300T / MS
Twist, 70 threads / 3 threads / dimension Weft: Semi-dull 100d / 48f, 2000T / MS
Twist, Z twist, 2 twists, 20 twists / inch Texture: plain weave

Coloring treatment (a) greige → refining (boiling water) → relaxing (11
0 ℃) → Intermediate set (190 ℃) → Weight loss (Condition A) → Dyeing (Condition B) (b) Raw machine → Refining → Relax → Intermediate set → Weight loss → Dyeing (Condition C) (C) Raw machine → Refining → Relax → Intermediate set → Weight loss → Printing (Condition D) (d) Giving machine → Paper raising → Refining → Relaxing → Intermediate set → Weight loss → Dyeing (Condition B)

Condition A (weight reduction) Weight reduction method: hanging weight reduction NaOH 15 g / l boiling x 60 minutes, (weight reduction rate 25%)

Condition B (Dyeing) Dye: No. 1 Kayacryl Blue 3RLED 1% owf (vs. fiber weight) (Cationic dye manufactured by Nippon Kayaku Co., Ltd.) No. 2 Kayacryl Blue 3RLED 1% owf (Cationic dye manufactured by Nippon Kayaku Co., Ltd.) Dynicx Red NSE 1% owf (Disperse dye manufactured by Mitsubishi Kasei Hoechst Co., Ltd.)

No. 3 DIANICS RED NSE 1% owf (Disperse dye manufactured by Mitsubishi Kasei Hoechst Co., Ltd.) DIANIX BLUE BGSF 1% owf (Disperse dye manufactured by Mitsubishi Kasei Hoechst Co., Ltd.) pH: Prepare a dye bath to pH 5 with acetic acid Bath ratio: 1:30, 130 ℃ x 60 minutes

Condition C (dying dyeing) Dye: Same as condition B Bath ratio: 1: 8 Temperature rising speed: 80 ° C. to 3 ° C./min

Condition D (dyeing and printing) Ground dyeing: Dye: Kayacryl yellow 3GSED 0.5%
owf (Cationic dye manufactured by Nippon Kayaku Co., Ltd.) Bath ratio 1:30, 120 ° C x 60 minutes Printing: Overprinting each pattern of flowers, leaves, and ground with the following dyes: Dye: Hana 1 Dynicx Red NSE 1% (Disperse dye manufactured by Mitsubishi Kasei Hoechst Co., Ltd.) Hana 2 Dynicx Yellow ACE 1% (Disperse dye manufactured by Mitsubishi Kasei Hoechst Co., Ltd.) Hana 3 Kayacryl Red GRLED 1% (Cationic dye manufactured by Nippon Kayaku Co., Ltd.)

Leaf Diamond Blue BGSF 1% (disperse dye manufactured by Mitsubishi Kasei Hoechst Co., Ltd.) Earth Diamond Blue BGSF 0.05% (disperse dye manufactured by Mitsubishi Kasei Hoechst Co., Ltd.) Diamond Red NSE 0.1% ( Mitsubishi Kasei Hoechst Co., Ltd. disperse dye) After printing, high-pressure steam 120 ℃ × 30 minutes treatment

The coloring results of the woven fabric obtained by the coloring treatments of (a) to (d) were as follows. No. in (a). In No. 1, the details were dyed blue and the exposed core of the thick part was left white, resulting in a stonewash-like multicolored expression of jeans. In addition, No. Two
The result was a deep melange tone with blue purple in the details and red in the thick exposed core, making it look purple as a whole. Furthermore N
o. In No. 3, a level dyeing with little difference in purple details and thick area was obtained. These are soft and supple luxury products with a dry touch and swelling. In Nos. 1 and 2, multicolor expressions excellent in designability were obtained.

(B) No. In No. 1, a multicolored expression with a high design was obtained by a stonewash-like mixed color from light to dark due to the synergistic effect with the spot dyeing effect. In addition, No. In No. 2, similarly, a melange effect having a high design property in which a mixture of hues close to a complementary color relationship of light to dark colors is arranged was obtained. No. No. 3 was limited to the usual expression of spot dyeing.

In (c), the following color arrangement was obtained, and multicolor expression excellent in designability and commercialability was obtained as a whole. Flower 1: As a whole, a reddish orange color was exhibited, and a deep multicolored expression in which reds were independently arranged in the reddish orange was obtained. Flower 2: A deep solid yellow color was obtained. Flower 3: A cine-like expression was obtained in which the details were orange and the thick exposed core was left white. Leaf: As a whole, it had a bluish green color, and the exposed core portion in the thick part was dyed in blue to give a deep multicolored expression. Ground: Beige as a whole, and the exposed core of the thick part was a multicolored expression with a rich purple design.

In (d), the same hue as in (a) was mixed, but due to the effect of brushing, a multicolored expression with a peach texture and rich in design was obtained with a different feeling of mixing. .

(Example 2) Polyethylene terephthalate was used as the core component, and polyethylene terephthalate was used as the sheath component, using a cationic dye dyeable modified polyethylene terephthalate obtained by copolymerizing 2.25 mol% of 5-sodium sulfoisophthalic acid and 5.0 mol% of adipic acid. The bright part 15 with a thick part obtained by spinning and semi-drawing into a circular cross section with a sheath component / core component = 1/1
0d / 48f thick and thin composite fiber multifilament yarn,
The cloth was woven under the following conditions and subjected to alkali reduction treatment and coloring treatment.

Woven warp yarn: Bright 150d / 48f, 1000T / MS
Twist, 55 feathers / 3 threads / dimension Weft: Bright 150d / 48f, 1000T / MS
Twist, 115 strands / inch Structure: 2/24 Twill weave Coloring machine → Refining (boiling) → Liquid flow relaxation (110
℃) → Intermediate set (190 ℃) → Weight loss (condition E) → Dyeing (condition F)

Condition E (weight reduction) Weight loss method: Suspended weight loss NaOH: 10 g / l Boiling x 0, 45, 60 minutes (weight reduction rate 0, 25, 35 wt
%) Condition F (dyeing) Same as condition B of Example 1, but the dyeing temperature is 120 ° C.
I chose

The coloring results of the woven fabric obtained by the coloring treatment are as follows. No. In No. 1, when the weight loss rate is 0 wt%, the whole is blue, the thick part and the details are both blue, and the weight loss rate is 2
When the amount is 5 wt%, the whole is slightly pale blue, and the thick portion remains white, and the details are blue. When the weight reduction rate is 35 wt%, the entire is pale blue, the thick portion remains white, the details are blue. In 2, when the weight loss rate is 0 wt%, the whole is purple, and the thick portion and the detail are both purple. When the weight loss rate is 25 wt%, the entire is reddish purple, the thick portion is red, the detail is purple, and the weight loss rate is 35 wt%. In the case of No. 2, the whole is a reddish purple, the thick part is red, and the details are reddish purple. In 3, the weight loss rate is 0-35w
At t%, all were purple, and both the thick part and the details were purple.

The thick and thin composite fibers constituting this woven fabric are of a type in which the thick portion has a longer length. In No. 1, the thick white part left behind, which was not possible with ordinary thick and thin fibers, produced a multicolored expression rich in design. In addition, No. In No. 2, similarly, a thick slab-like expression was added to the effect of mixing different colors, and a woven fabric with high commercial characteristics and high design was obtained. No. In No. 3, it was dyed uniformly. In particular, those with a weight loss rate of 25 wt% and 35 wt% had excellent feel characteristics of the thick and thin composite fibers, a feeling of swelling and a dry touch, and were highly commercialized with excellent drapeability. .

The thick and thin composite fibers used had extremely excellent strength even after the alkali reduction treatment, as compared with the conventional thick and thin fibers.

(Example 3) A cationic dye dyeable modified polyethylene terephthalate prepared by copolymerizing 2.0 mol% of 5-sodium sulfoisophthalic acid was used as a sheath component, and polyethylene terephthalate was used as a core component. With a core component = 1/2, a circular cross-section was spun at a temperature of 285 ° C, and was drawn at a take-up speed of 1800 m / min, a first stage draw ratio of 1.595, a temperature of 115 ° C, and a second stage draw ratio of 1.
015, fineness unevenness obtained by two-stage drawing at a temperature of 120 ° C. 0.6
% Of thick semi-composite fiber multifilament yarn with 50% / 24% of the thick part dispersed therein was subjected to alkali weight reduction treatment at a weight reduction rate of 20 wt% in an aqueous solution of NaOH 9.9 g / l under boiling.

When this yarn was dyed with the same red cationic dye as used in Example 1, the exposed core part of the thick part of the fiber remained white, the other part was red, and it was further dyed with a blue disperse dye. However, the exposed core part of the thick part of the fiber was blue, and the other part was reddish purple, and a multicolor expression yarn was obtained.

[0048]

EFFECTS OF THE INVENTION According to the present invention, the cost is low because the fiber itself can be used for multicolor expression without requiring a process for mixing fibers and special dyeing processing conditions.
The same alkali reduction processing and dyeing finishing processing as those applied to ordinary polyester are applied to the process, and it is possible to express extremely multiple colors compared to conventional products, and the thick and thin effects are synergized, which is excellent. It is possible to obtain a textile product that has a good texture and is rich in design. Further, the present invention is economically advantageous because it is possible to obtain a textile product with high productivity even in a small processing lot.

The present invention includes the following embodiments. (1) A composite fiber in which a modified polyester having different dyeability is arranged in the sheath part and an unmodified polyester is arranged in the core part, and the composite fiber has a large and small thickness in the fiber axis direction and at least the thick core part is exposed. Polyester sheath core composite fiber characterized by being (2) The polyester sheath core conjugate fiber according to (1), wherein the modified polyester is a modified polyester that is dyeable with a cationic dye or an acid dye or is easily dyeable with a disperse dye.

(3) The cationic dye-dyeable modified polyester has ethylene terephthalate as a main repeating unit and contains 5-sodium sulfoisophthalic acid in an amount of 1.5 to 3.
The polyester sheath core conjugate fiber according to (2), which is a modified polyester copolymerized with 5 mol%. (4) The polyester sheath core conjugate fiber according to (1), wherein the sheath portion and the exposed core portion, and the thick portion and the details are respectively colored in different colors.

(5) An unstretched composite fiber containing a modified polyester having a different dyeability as a sheath component and an unmodified polyester as a core component is semi-stretched to form a thin fiber in the fiber axis direction, and then an alkali weight loss is performed. A method for producing a polyester sheath core composite fiber, which comprises treating and decomposing and removing at least a thick sheath component of the fiber. (6) A non-stretched composite fiber having a sheath component of a modified polyester that is dyeable with a cationic dye or an acid dye or easily dyed with a disperse dye and a core component of an unmodified polyester is 0.45 to 0.60 at a maximum elongation ratio. (5) The method for producing a polyester sheath core conjugate fiber according to (5), which comprises drawing in two stages.

(7) Cationic dye As a dyeable modified polyester, the main repeating unit is ethylene terephthalate, and 5-sodium sulfoisophthalic acid is added in an amount of 1.5 to 5.
The method for producing a polyester sheath core conjugate fiber according to (6), which uses a modified polyester copolymerized with 3.5 mol%.

(8) Cationic dye or acidic dye A modified polyester dyeable or easily disperse dye is used as a sheath component, and an unmodified polyester is semi-stretched to form a thin fiber in the axial direction of the fiber, and then alkali weight loss is performed. At least the sheath component of at least the thick portion of the fiber is decomposed and removed by treatment, and then colored with a cationic dye or an acidic dye and / or a disperse dye to color the sheath portion and the exposed core portion and the thick portion and the detail with different colors. A method for producing a polyester sheath core composite fiber, comprising: (9) The method for producing a polyester sheath core composite fiber according to (8), wherein a raising treatment is performed prior to the alkali weight reduction treatment.

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[Procedure amendment]

[Submission date] October 24, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0015

[Correction method] Change

[Correction content]

The polyester sheath core conjugate fiber of the present invention is preferably produced as follows. The polyester used in the present invention is a combination of modified and unmodified polyesters having different dyeing properties. The modified polyester is a sheath component, the unmodified polyester is a core component, or the modified polyester having a high degree of modification is a sheath component, and the modified degree is The modified polyester having a small value of (4) is used as the core component, but preferably, the modified polyester which is dyeable with a cationic dye, dyeable with an acid dye or easily dyed with a disperse dye is used as the sheath component, and the unmodified polyester is used as the core component.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0028

[Correction method] Change

[Correction content]

Woven warp yarn: Semi-dull 100d / 48f, 300T / MS
Twist, 70 threads / 3 threads / dimension Weft: Semi-dull 100d / 48f, 2000T / MS
Twist, Z twist, 2 twists, 120 twists / inch Texture: plain weave

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0031

[Correction method] Change

[Correction content]

Condition B (Dyeing) Dye: No. 1 Kayacryl Blue 3RLED 1% owf (vs. fiber weight) (Cationic dye manufactured by Nippon Kayaku Co., Ltd.) No. 2 Kayacryl Blue 3RLED 1% owf (Cationic dye manufactured by Nippon Kayaku Co., Ltd.) Dynicx Red NSE 1% owf (Disperse dye manufactured by Mitsubishi Kasei Hoechst Co., Ltd.)

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location D06P 3/52 Z 3/87 C D06Q 1/00 // D06M 101: 32 (72) Inventor Kawashima Nori 2 2-1, Ushikawa-dori, Toyohashi-shi, Aichi Sanryo Rayon Co., Ltd. Toyohashi Plant

Claims (2)

[Claims] 1. A composite fiber in which one of two kinds of polyesters having different dyeing properties is arranged in a sheath portion and the other is arranged in a core portion, and has a large and small thickness in the fiber axis direction, and at least a thick portion. A polyester sheath core composite fiber, which is characterized in that a part of its core is exposed. 2. An unstretched composite fiber having one of two polyesters having different dyeing properties as a sheath component and the other as a core component is semi-stretched to form a thick and thin fiber in the fiber axis direction,
A method for producing a polyester sheath core composite fiber, which comprises decomposing and removing at least a thick sheath component of the fiber by alkali reduction treatment.