JP2935008B2 - Polyester core-sheath composite fiber and method for producing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyester core-sheath type composite fiber and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, as a means for expressing multicolors of a textile product, cotton-dyed and mixed fibers having different hues and densities by blended cotton or mixed spinning, or yarn-dyed dyed fibers are mixed and twisted. , Mixed weaving, knitting, or mixed with spun yarn and fibers with different dyeability before dyeing to create multi-color expression such as cine, melange, chambre, stonewashing, bleaching, etc. It is obtained by special processing such as fibrillation or ring-dyed coloring of the fiber surface layer only, which has been 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. Then, as such a thick and thin fiber, a core-sheath type composite spinning with two components having different dyeing properties,
Using a frictional force between the yarn and the roller surface on a take-up roller heated to a high temperature, a random stretching unevenness is generated between all the constituent filament fibers to form a thick and thin shape, and further alkali reduction treatment is performed to form a composite. A polyester core-sheath type composite fiber is known in which the sheath component of at least the thick part of the fiber is decomposed and removed, and the respective dyeing properties of the exposed core part and sheath part are exhibited. However, this thick and thin composite fiber was not sufficiently developed to satisfy the dyeing property of the core, although the effect of multicolor expression of the hue and density of marbling tone was obtained.

[0004]

DISCLOSURE OF THE INVENTION As a result of studying thick and thin core-sheath type composite fibers, the present invention has found a polyester core-sheath type composite fiber which exhibits a wide variety of multicolor expression effects which have never been known. SUMMARY OF THE INVENTION It is an object of the present invention to provide a polyester core-sheath type conjugate fiber that exhibits a clear multicolor expression effect of different hues and different concentrations.

[0005]

[Wherein DR is the draw ratio, MDR is the maximum draw ratio of the undrawn yarn, P ₁ T is the temperature (° C.) of the first friction resistance pin in the drawing region, and P ₂ T is the temperature of the second friction resistance pin ( C), Tc represents the crystallization temperature (°C) of the undrawn yarn, and Tg represents the glass transition temperature (°C) of the undrawn yarn]

[0006]

[0007]

The two polyesters constituting the core-sheath type composite fiber of the present invention have different dyeing properties, one of which is a dye having a dyeability for a cationic dye or an acid dye or an easily dyeing property for a disperse dye. Typical polyesters are polyesters, and the other are unmodified polyesters which are non-dyeable to cationic dyes and acid dyes or non-easy dyeing to disperse dyes.

The modified polyester is a polyester which has ethylene terephthalate as a main repeating unit and is modified to be dyeable or easily dyeable, and the unmodified polyester is
A polyester containing ethylene terephthalate or butylene terephthalate as a main repeating unit. As the modified polyester, a modified polyester that is dyeable with a cationic dye, dyeable with an acid dye, or easily dyed with a disperse dye is used. From the viewpoint of ensuring strength and easily providing multicolor expression, the modified polyester is unmodified on the sheath part. 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 5-sodium sulfoisophthalic acid in an amount of 1.5 to 3.5 mol %.

As the acid dye dyeable modified polyester, ethylene terephthalate obtained by a known method may be used together with an amino alcohol such as an N-alkyl-substituted diethanolamine or a base-containing ester-forming compound such as a tertiary amino-containing glycol. Polymerized modified polyesters, modified polyethylene terephthalates mixed with homopolymers or copolymers of vinylpyridine are 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.

Specific examples of the unmodified polyester include polyethylene terephthalate and polybutylene terephthalate, and the unmodified polyester may contain less than 5 mol% of a copolymerization component or a blending component. Polyethylene terephthalate is preferably used.

The composite ratio of the sheath portion to the core portion in the fiber cross section of the core-sheath type composite fiber is 1/3 to 1/1 in terms of the area ratio of the sheath portion/the core portion.
Is preferred. When the thickness of the sheath portion is too small, the coloring with the dye is lightened, and when the thickness is too large, it becomes difficult to secure the strength when the core portion is exposed.

The core-sheath type composite fiber of the present invention may have any cross-sectional shape, such as a round cross section, a triangular cross section, a multilobe section, or an atypical cross section, and the shape, number and position of the core are also particularly limited. It is not done. The core-sheath type composite 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 the variation coefficient CV of the thickness unevenness of the entire yarn is 5 to 7%, It is necessary that the frequency X value of thickness unevenness having a thickness variation rate of 15% or more with respect to the average value is 2 to 4 pieces/m.

The variation coefficient CV of the thickness unevenness of the entire yarn is 5 to 7%.
As a result, so-called slab-like spots are formed in which the thick parts of the constituent fibers are concentrated, and a clearer multicolor expression is provided. If the coefficient of variation CV is less than 5%, the thick portions of each fiber will be dispersed and the spots will not be noticeable, and even if a marbling effect due to multicolor dyeing or dyeing is obtained in the dyeing after the alkali reduction treatment, a clear multicolored expression is obtained. If it is not obtained and exceeds 7%, unnatural spots are formed, and streak-like spots in details are conspicuous and the quality is poor.

Here, the variation coefficient CV of thickness unevenness is a Worcester normal value under the conditions of a yarn speed of 8 m/min and a chart speed of 50 cm/min using Eve Nestester KET-80C manufactured by Keiki Kogyo Co., Ltd. It is a value obtained by measurement and serves as an index showing the magnitude of deviation from the average value.

Further, the variation rate of the thickness with respect to the average value is 15
If the frequency X value of the thickness unevenness is more than 2%/m, the dyed part of the core becomes unclear in the dyeing after the alkaline reduction treatment, and a sufficient multicolor effect cannot be obtained. Beyond, the dyed part of the details becomes unclear. This frequency X value was obtained by calculating the number of locations showing a thickness of 15% or more of the average thickness between 8 m of the yarn length of the chart obtained under the same conditions as the measurement conditions of the coefficient of variation CV It is the number converted to the number of, and represents the frequency of thickness unevenness.

At least the whole or part of the thick core of the core-sheath type composite fiber of the present invention 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, although the core portion of the details other than the thick portion may be exposed as necessary, it is preferable to limit the exposure of a part of the details other than the thick portion.

The core-sheath type composite fiber of the present invention is preferably produced as follows. The polyester used in the production method of the present invention is a combination of modified and unmodified polyesters having different dyeability, wherein 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. , A modified polyester having a small modification degree as a core component or a modified polyester as a sheath component,
Other modified polyester is used as a core component, but preferably,
A modified polyester dyeable with a cationic dye or an acid dye or easily disperse dye is used as a sheath component, and an unmodified polyester is used as a core component.

The modified and unmodified polyesters are used as a sheath component and a core component, respectively, and preferably, the sheath component and the core component are mixed in such a ratio that the area ratio of the sheath/core is 1/3 to 1/1. An unstretched yarn having a core-sheath composite structure obtained by spinning by a known core-sheath composite spinning method is used to make a thick fiber.
The composite spinning unstretched yarn used has a spinning speed of 1500 to 2500 m/m in order to form a good thickness difference.
It is preferably an undrawn yarn obtained under the in condition.

When the spinning speed is less than 1500 m/min,
Although the natural stretching area is large and a good difference in thickness can be obtained,
Since the thick portion has a low orientation, the breaking strength during alkali weight reduction treatment is significantly reduced, and the quality and process stability are impaired.
If it exceeds 2500 m/min, the naturally stretched region becomes small and a good difference in thickness cannot be obtained.

In the production method of the present invention, in order to form the thick portion and the fine portion in a dispersed manner, the unspun composite spun yarn needs to be stretched at a half draw ratio of the maximum draw ratio, that is, half drawn. Yes, preferably maximum draw ratio 0.45
By performing hot pin drawing at a magnification of ˜0.60 times, a thick and thin shape is formed in the fiber axis direction. The temperature of the first friction resistance pin in the hot pin drawing is set to the crystallization temperature of the undrawn yarn or lower, or a second friction resistance pin is further provided and the temperature of the second friction resistance pin is set to the glass transition temperature or higher and the crystallization temperature or lower. Temperature and
Heat-treat to give the desired shrinkage.

The degree of dispersion of the thick portion, the length of the thick portion, and the size of the thick portion in the formation of the thick and thin portions are adjusted by setting an appropriate combination of the draw ratio and the temperature of the first friction resistance pin.

The thick and thin core-sheath type conjugate fiber may be in any yarn form such as spun yarn, multifilament yarn, or false twisted yarn. In the manufacturing method of the present invention,
The thin core-sheath type composite fiber can be alkali weight-reduced in the form of yarn, but after weaving and knitting, the weight loss that is usually applied to the woven fabric and knitted fabric of polyester fiber in the form of woven fabric and knitted fabric. It is preferable to carry out alkali weight loss treatment in the processing.

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 the sheath portion of the core-sheath type composite fiber surface By imparting damage, the decomposition and removal of the thick part and the sheath part of the detail by the alkali in the alkali weight loss treatment are promoted, so that the multicolor expression is further improved.

For the alkali weight loss treatment, known methods and conditions using an alkali metal hydroxide such as sodium hydroxide are applied, and any treatment method can be used. In the present invention, at least the sheath component of the thick thin-sheath type composite fiber is decomposed and removed by the alkali reduction treatment. In the decomposition and removal of the sheath component by the alkali 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 of the sheath components are not decomposed and removed.

In the alkali weight loss treatment, the sheath component in the thick portion can be selectively removed to expose the core portion,
It is possible to arbitrarily change the ratio of the portions having different dyeability on the fiber surface at the weight loss rate of 15 to 50 wt %.

The alkali-sheathed core-sheath type composite fiber is dyed with a cationic dye or an acid dye and/or a disperse dye according to the dyeability of the sheath component and the polyester of the core component, and the sheath part and the exposed core part are then treated. The thick portion and the details can be colored in different colors. In addition, it is possible to carry out various coloring such as leaving the exposed core portion dyed in one-sided printing such as leaving white, or in some cases uniformly dyeing the whole.

As the dyeing method, known methods and devices such as dip dyeing, printing or a combination of dipping and printing, discharge printing in printing, and dye-proofing are applied depending on the form of the fiber, and are not particularly limited. Absent.

[0031]

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

(Example 1) Intrinsic viscosity 0.72, density 1.
Intrinsic viscosity of 0.58, which is obtained by copolymerizing polyethylene terephthalate having 38 g/cm ³ and a melting point of 256° C. as a core component and 2.0 mol% of 5-sodium sulfoisophthalic acid.
A cationic dye dyeable modified polyethylene terephthalate having a density of 1.38 g/cm ³ and a melting point of 252° C. is used as a sheath component, and a spinning temperature of 285 is obtained with a nozzle having 48 nozzle holes.
C., composite ratio (area ratio) sheath/core=1/2, and spinning was performed on a round cross section at a take-up speed of 1800 m/min to obtain an undrawn yarn having a 174 denier (d) and a maximum draw ratio of 3.3.

This undrawn yarn was drawn at a draw ratio of 1.736, a first friction resistance pin temperature of 58° C. and a second friction resistance pin temperature of 10.
Stretched at 6° C., semi-dal, 100 d/48 f, breaking strength 2.3 g/d, breaking elongation 70%, boiling water shrinkage 45%,
Average deviation rate 5.1%, variation coefficient of thickness unevenness CV 6.2%,
A slab-like thick thin-core-sheath type composite fiber multifilament stretched yarn having a frequency X value of thickness unevenness with a variation rate of thickness of 15% or more with respect to an average value of 2.8/m was obtained. Further, this drawn yarn was woven under the following conditions and subjected to alkali weight reduction treatment and dyeing treatment.

Weaving: Warp: Semi-dull 100d/48f, 300T/M(S
(Twist), 70 threads/3 threads/dimension Weft: Semi-dull 100d/48f, 2000T/M(S
Twist, Z twist, 2 twists), 120 twists/inch Texture: plain weave

Treatment process: greige→refining (boiling water)→relaxation (110° C.)
→ Intermediate set (190℃) → Alkali weight loss →
staining

Alkali weight loss: Weight loss method: Hanging weight loss NaOH: 15 g/l Boiling x 60 minutes, (weight loss rate 25%) Dyeing: Dye: Kayacryl blue 3RLED 1%owf (vs. fiber weight) (Nippon Kayaku Co., Ltd.) Cationic dye) Dye: Dynics Red NSE 1%owf (Disperse dye manufactured by Mitsubishi Kasei Hoechst Co., Ltd.) Bath ratio: 1:30, 130°C x 60 minutes

The dyeing result of the woven fabric obtained by the dyeing treatment is that when dyed only with the dye, the details are dyed in blue, the exposed core of the thick part is left white, and the conventional thick marbled composite fiber The resulting clear thick part was left white, and a multicolor expression rich in design was obtained. Also, when dyed with a dye or dye, the details are blue-violet and the thick exposed core is red. It was a thing. These dyed woven fabrics also had an excellent swelling feeling and a dry touch that the thick and thin fibers had, and were rich in drape.

(Comparative Example 1) Intrinsic viscosity 0.72, density 1.
Intrinsic viscosity of 0.58, which is obtained by copolymerizing polyethylene terephthalate having 38 g/cm ³ and a melting point of 256° C. as a core component and 2.0 mol% of 5-sodium sulfoisophthalic acid.
A cationic dye dyeable modified polyethylene terephthalate having a density of 1.38 g/cm ³ and a melting point of 252° C. is used as a sheath component, and a spinning temperature of 285 is obtained with a nozzle having 48 nozzle holes.
C., composite ratio (area ratio), sheath/core=1/2, and spinning in a round cross section at a take-up speed of 1800 m/min to obtain an undrawn yarn having 162d and a maximum draw ratio of 3.3.

The unstretched yarn was drawn at the first stage draw ratio of 1.595.
Fold, second stage draw ratio 1.015 times, first stage draw temperature 11
Stretching at 5° C., second stage drawing zone temperature 120° C., semi-dal, 100 d/48 f, breaking strength 1.9 g/d, breaking elongation 78%, boiling water shrinkage rate 18%, average deviation rate 2.0%, Variation of thickness variation coefficient CV 2.4%, variation rate of thickness with respect to average value is 15% or more Frequency of thickness variation X value is 0/m Thick core-sheath type composite fiber multifilament drawn yarn It was Further, this drawn yarn was woven under the same conditions as in Example 1,
Alkali weight loss treatment and dyeing treatment were performed.

The dyeing result of the woven fabric obtained by the dyeing treatment shows a multicolor expression of the stonewash of jeans when dyed only with the dye, and when it is dyed with the dye and the dye, it looks purple as a whole. Although it showed a melange-like multicolor expression, it remained white and the clarity of each color was not sufficient.

(Comparative Example 2) Intrinsic viscosity 0.72, density 1.
Intrinsic viscosity of 0.58, which is obtained by copolymerizing polyethylene terephthalate having 38 g/cm ³ and a melting point of 256° C. as a core component and 2.0 mol% of 5-sodium sulfoisophthalic acid.
A cationic dye dyeable modified polyethylene terephthalate having a density of 1.38 g/cm ³ and a melting point of 252° C. is used as a sheath component, and a spinning temperature of 285 is obtained with a nozzle having 48 nozzle holes.
C., composite ratio (area ratio) sheath/core=1/2, and spinning was performed on a round cross section at a take-up speed of 1800 m/min to obtain an undrawn yarn with 241d and a maximum draw ratio of 3.4.

This unstretched yarn was drawn at the first stage draw ratio of 1.011.
Fold, second stage draw ratio 2.380 times, first stage draw temperature 85
C., the second stage drawing zone temperature is 145.degree.
100d/48f, breaking strength 5.0g/d, breaking elongation 2
8%, boiling water contraction rate 12%, average deviation rate 0.7%, variation coefficient CV of thickness unevenness CV 0.8%, frequency variation X value of thickness variation of 15% or more of thickness variation rate with respect to average value is 0 An ordinary core-sheath type composite fiber multifilament stretched yarn having a number of K/m was obtained. Furthermore,
The drawn yarn was woven under the same conditions as in Example 1 and subjected to alkali weight reduction treatment and dyeing treatment.

The coloring result of the woven fabric obtained by the dyeing treatment is as follows: when dyed only with the dye, the whole is colored blue, and when dyed with the dye and the dye, it is colored violet as a whole, No discoloration or contrast effect was observed.

[0044]

EFFECTS OF THE INVENTION The polyester core-sheath type composite fiber according to the present invention is a slab-like thick and thin fiber, so that it is possible to express an extremely clear multicolor as compared with a conventional product, and further, the thick and thin effect. By being synergized with each other, it is possible to obtain a textile product having a good texture and rich in design. In addition, the polyester core-sheath type composite fiber according to the present invention is a material that is economically advantageous because it can provide a fiber product with high productivity and multicolor expression even in a small processing lot.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁶ Identification code FI D06M 101:32 D06M 5/02 G (56) References JP-A-55-116819 (JP, A) JP-A-2-221416 ( JP, A) JP-A-7-292516 (JP, A) JP-A-7-173766 (JP, A) JP-A-63-75133 (JP, A) JP-B 1-37512 (JP, B2) (58) ) Fields surveyed (Int.Cl. ⁶ , DB name) D06M 11/38 D01F 8/14 D01F 6/62 303

Claims (3)

(57) [Claims] 1. A composite fiber in which one of two polyesters having different dyeability is arranged in a sheath portion and the other in a core portion, which has a large and small thickness in the fiber axis direction, and as a whole yarn. The variation coefficient CV of the thickness unevenness is 5 to 7%, and the frequency X value of the thickness unevenness having a thickness variation rate of 15% or more with respect to the average value is 2 to 4/m, and at least the thick portion of the composite fiber Part of the core of the
Polyester core-sheath type composite fiber characterized by that. 2. A composite spun unstretched yarn having one of two polyesters having different dyeability as a sheath component and the other as a core component is hot-pin stretched under the following conditions (1) to (3). After forming a thick and thin fiber in the fiber axis direction , alkali weight reduction treatment
A method for producing a polyester core-sheath type composite fiber, which comprises decomposing and removing a sheath component of at least a thick part of a composite fiber. (1) MDR×0.45≦DR≦MDR×0.60 (2) P ₁ T≦Tc (3) Tg≦P ₂ T≦Tc [wherein DR is the draw ratio and MDR is the undrawn yarn Maximum draw ratio, P ₁ T is the temperature (° C.) of the first friction resistance pin in the drawing region, P ₂ T is the temperature of the second friction resistance pin (° C.), Tc is the crystallization temperature (° C.) of the undrawn yarn, Tg represents the glass transition temperature (°C) of the undrawn yarn] 3. A composite spun undrawn yarn, wherein the composite ratio of the sheath portion and the core portion in the fiber cross section is 1/3 in terms of the sheath portion/core portion area ratio.
~ 1/1, spinning speed 1500-2500 m/m
The method for producing a polyester core-sheath composite fiber according to claim 2, wherein the undrawn yarn obtained under the condition of in is used.