KR20190005159A - Core-sheath composite fibers and fabrics thereof - Google Patents

Abstract

The present invention discloses a core-sheath composite fiber, wherein the sheath component is polyamide, and the core component is a usable polyester, wherein the stretching viscosity (M) of the polyamide in the fiber and the stretching viscosity N) satisfies the condition of MN? 0 Pa.s under the same temperature of not less than 255 占 폚. The fibers are not only exceptionally lightweight through post-reduction treatment, but also have excellent washing fastness after dyeing.

Description

Core-sheath composite fibers and fabrics thereof

The present invention relates to a core-sheath composite fiber having good dye fastness and excellent dyeing effect and a fabric containing the fiber.

In general, when selecting sportswear, it should not only look good when worn, but should also be as low in weight as possible, and should not worry about sweating. Therefore, there is a higher demand for light weight of the fabric of the dress, especially the fabric for sportswear, and hygroscopic performance. Although the natural fibers have good hygroscopicity and are comfortable to wear, the lightweighting ratio of the natural fibers is too low to satisfy the lightness required in sports, and may cause a predetermined weight to the human body during exercise. In the synthetic fiber direction, the light weight of the fiber is realized through the method of post-eluting mainly the hollow fiber or the composite fiber; A chemical method of copolymerizing or blending with a hygroscopic material, or a method in which the hygroscopicity of the fiber is realized through roughening of the surface of the fiber, a step of releasing the cross-section, a physical method of porous or hollow fiber structure, Use it directly.

Chinese patent CN1284140A discloses a polyamide composition multifilament yarn having a cross-sectional shape of C type and a hollow cross-section having a porosity of 15% or more. Although the polyamide fiber itself can satisfy the requirements of the sports fabric in terms of moisture absorption and comfort, the polyamide fiber has a low degree of molding because the polyamide single component yarn is cooled , A hollow ratio that is less than about 25% is determined, so there is no definite lightweight feeling and there is no apparent effect in reducing the weight of clothes.

Chinese patent CN101748512A discloses a polyester conjugated fiber having a cis-core structure in which the polymer of the sheath layer is polyester or polyamide and the polymer of the core layer is an alkaline-soluble copolyester. Although the fibers may also have a light weight and hygroscopicity after the weight loss, the polyamide can not be stretched sufficiently due to the affinity between the polyester and the polyamide and the viscosity difference due to the spinning temperature, and the fibers and the subsequent fabric are dyed with an acidic dye for polyamide The washing fastness is lowered, and the dyeing effect is poor.

An object of the present invention is to provide a core-sheath type conjugate fiber comprising a polyamide as a sheath component and a usable polyester as a core component. The fiber can obtain a hollow polyamide fiber having good light weight and good hygroscopicity after weight reduction, and has a good dyeing effect after dyeing polyamide with an acid dye and has excellent washing fastness. The fibers of the present invention can be applied to the manufacture of fabrics, and the fabrics after weight reduction are well-suited to be used as sportswear fabrics.

The technical solution of the present invention is as follows.

The sheath component in the core-sheath composite fiber is polyamide, and the core component is an available polyester. The stretched viscosity (M) of the polyamide in the fiber and the stretched viscosity (N) of the usable polyester satisfy a condition of M-N? 0 Pa.s, preferably M-N? 100 Pa.s, at the same temperature of 255 ° C or higher.

The weight ratio of the polyamide and the usable polyester in the fibers is preferably 70:30 to 30:70.

It is preferable that 5-sodiosulfo isophthalic acid is contained in an amount of 0.3 to 0.5 wt% of the total amount of the polyester calculated as the S element among the usable polyesters.

In the cross-section of the fiber, the polyamide as the sheath component is preferably C-type or U-shaped.

The present invention further discloses a fabric containing the core-sheath type conjugate fiber.

(Effects of the Invention)

The fibers of the present invention are not only excellent in light weight and hygroscopic property but also excellent in dyeing effect after dyeing and in washing fastness.

1 is a cross-sectional view of a core-sheath composite fiber according to the present invention.
Fig. 2 is a cross-sectional view of the core-sheath composite fiber of the present invention after the weight reduction treatment. Fig.

The core component of the core-sheath conjugated fiber of the present invention is composed of the available polyesters, the sheath component is composed of polyamide, and after the weight reduction, a polyamide fiber having a hollow, C-shaped or U- can do.

Relative to the polyamide fibers formed through direct release or hollow spinnerets, elution of the available polyesters after core-cis complex spinning can result in relatively large porosity, resulting in a distinct lightweight effect . In the spinning process through the direct release or hollow radiation plate, the final lightweight effect is affected because the polymer extruded from the spinnerets offsets the formation of voids to a very large extent due to the expansion action.

The compatibility and the spinning temperature are different in the composite spinning of the polyamide and the useable polyester in the prior art, so that the polyamide can not be stretched sufficiently, so that the composite fiber and the subsequent fabric are made acidic After dyeing with the dye, the wash fastness is reduced and the dyeing effect is not good.

The present invention relates to a process for producing a polyamide composite yarn in a process of composite spinning of polyamide by setting the stretching viscosity (M) of the polyamide to be greater than or equal to the stretching viscosity (N) The polyamide can be stretched under tension, and the orientation of the polyamide is not inhibited, so that the molecular orientation can be sufficiently achieved. The fully drawn polyamide part has good washing fastness after dyeing and excellent dyeing effect. If the polyamide is not fully oriented or only partially oriented, the space to which the dye is attached after the dyeing becomes large, resulting in the dropout of the dye in subsequent washing of the fiber and fabric, resulting in poor wash fastness .

If the stretching viscosity of the polyamide is M and the stretching viscosity of the usable polyester is N, that is, at the same temperature of 255 占 폚 or more, M-N? 0 Pa.s, preferably M-N? 100 Pa.

The weight ratio of the polyamide to the usable polyester in the core-cis composite fiber of the present invention can be arbitrarily changed within a known range. In order to obtain a polyamide fiber having better lightness after weight loss, the weight composite ratio is preferably 70:30 to 30:70, and more preferably 60:40 to 40:60.

The polyamide may be nylon 6, nylon 66, modified copolymers thereof, or the like.

The usable polyester is mainly formed by copolymerization of an aromatic dibasic acid or its esterified product, an aliphatic diol and a 5-sodiosulfoisophthalic acid type. Further, a polyalkylene glycol copolymerization component may be further contained in the usable polyester.

The sulfonic acid group is a polar hydrophilic group and has an electron withdrawing effect. The introduction of a 5-sodiosulfoisophthalic acid compound changes the regularity of the polyester molecular chain, and the progress of the alkali solution penetration and alkali reduction process . It is preferable that the 5-sodiosulfoisophthalic acid compound accounts for 0.3 to 0.5 wt% of the total amount of the usable polyester calculated as the S element.

However, due to the steric hindrance formed by the sulfonic acid salt compound and the polarity effect, the viscosity of the polyester melt may be increased, which may affect the spinnability. Therefore, when the soft segment polyalkylene glycol is introduced into the polyester, the rigidity of the polyester molecule can be remarkably improved, the bagability of the polyester can be improved, and the elution performance of the polyester can be further improved have.

The aromatic dibasic acid or its esterified product is preferably terephthalic acid, and the aliphatic diol is preferably ethylene glycol, and the polyalkylene glycol is preferably polyethylene glycol.

In the cross section of the core-sheath composite fiber of the present invention, it is preferable that the sheath component polyamide is C type or U type.

The present invention further discloses fabrics containing the core-sheath conjugated fibers. A fabric made from 100% of the core-sheath composite fibers may have a lightweight ratio of 30% or more after the weight reduction process.

The core-sheath composite fiber of the present invention can be produced by using a spinning method well known in the art. For example, a polyamide chip satisfying the viscosity difference of the present invention is melted at a constant weight ratio, and a composite radial plate is injected, spun and wound to obtain a nylon composite filament. The weight ratio is preferably 70:30 to 30:70, and more preferably 60:40 to 40:60.

The spinning method may be a one-step molding method or a two-step molding method in which a pre-spinning and a stretching and twisting are performed.

The present invention also relates to a fabric containing at least said core-sheath conjugated fiber, and the fabrication method of the fabric may use a method known in the prior art. After obtaining the fabric, the leachable treatment may be carried out under suitable alkali dissolution conditions to obtain a lightweight fabric. When the remaining polyamide fibers after the reduction are observed, the cross-sectional shape of the polyamide fibers can be observed, and preferable cross-sectional shapes of the polyamide fibers are C type or U type.

If the fabric is entirely made of core-sheath composite fibers, after weight reduction, the preferred weight of the fabric in the preferred technique can reach 30% or more before weight loss.

In the case of the weight loss treatment, a conventional treatment process may be used. In general, the treatment is carried out in a NaOH solution having a concentration of 1% to 5% and a bath ratio of 100 to 200.

Formally, since the stretching viscosity of the polyamide in the core-sheath composite fiber of the present invention is greater than or equal to the stretching viscosity of the available polyester, the polyamide can be stretched sufficiently during the spinning process, After removal, it is possible to obtain a polyamide fiber excellent in light weight, hygroscopic property, excellent dyeing effect and excellent dye fastness, and a fabric containing the fiber.

The test method of the parameter handled in the present invention is as follows.

1. Weight of each component in the core-sheath composite fiber

(1) Test method of polyamide: The core-sheath composite fiber was placed in a 1% NaOH solution and subjected to weight loss treatment at a ratio of 1: 100. After the weight loss was completed, the polyamide was obtained and weighed after drying .

(2) Test method of available polyester: The core-sheath composite fiber was treated according to GB-T2910.7-2009, and after the polyamide was completely dissolved, the used polyester was obtained and dried and weighed.

2. Content of 5-sodiosulfoisophthalic acid-type compounds in the polyesters used

The content of sulfur element was measured by an elemental analyzer for the usable polyester after drying obtained in Test Method 1 (2), and the content of 5-sodiosulfoisophthalic acid compound after conversion was obtained. The final result was taken as the mean value of the 5 tests.

3. Drawing viscosity

The shear viscosities of the polyamide and the usable polyester were tested at the same temperature of 255 ° C or higher using a capillary rheometer and the polyamide and the usable polyester obtained in Test Method 1 were respectively sampled, Zero shear viscosity was obtained and the stretching viscosity was three times the viscosity at zero shear.

4. Cross-sectional shape of core-sheath composite fiber

SEM photographs were used to observe the cross-sectional shape of the fibers.

5. Wash fastness

Tested according to JIS0844-2011 and GB-T3921-2008 standards.

6. Weight loss rate of fabric

A fabric was prepared from the core-sheath composite fiber of the present invention, and a predetermined amount of fabric was immersed in a NaOH solution having a concentration of 1% to 5% and a bath ratio of 100 to 200, and then the weight of the final weight- When no further changes were to be ensured, the remaining fabric was taken out, dried and weighed.

Weight loss ratio = (weight before weight loss - residual weight after weight loss) / weight before weight loss × 100%.

7. Light weight ratio of fabric

The fabrics were prepared from the core-sheath conjugate fiber of the present invention, the fabric of a predetermined area was taken out to completely remove the used polyester after the reduction, and the weight after weighing the fabric after weight reduction was designated as M1. The diameters of amide single fibers were observed; The same diameter and same component polyamide fibers were weighed and weaved under the same weaving conditions, and the weighed weights of the same area were M2. The calculation of the lightweight ratio of the fabric is as follows:

Lightweight ratio of fabric = (M2-M1) / M2 100%.

Hereinafter, the present invention will be described in more detail with reference to examples.

Example 1

The nylon 6 (N6) of 70wt% and the usable polyester chips of 30wt% were preliminarily crystallized and dried so that the water content was 100ppm or less. Each of the chips was put into a bin, Cis-type composite spinning pack under the condition that the temperature is controlled at about 290 占 폚 by a spinning manifold, and the as- spun conjugated fiber was spinned and cured by cooling under conditions of a cross air jet speed of 40 m / min, and then uniformly oiled to the fiber through an oil ring nozzle to aggregate the fibers and reduce friction. The oil feed rate was 1.0%.

After the fibers having been collected by the oiling ring passed through the spinning tube and entangled through the preliminary entangling machine, the filaments entered the first heat roller 1HR (at a temperature of 80 캜), wound 6 times on the first heat roller, The sheet was allowed to enter the second heat roller 2HR and was also wound six times (the temperature was 160 DEG C), and the draw ratio between the first heat roller and the second heat roller was 2.50. After the stretched fibers were entangled with each other through the primary entangling machine under the second heat roller, the fibers were wound into two layers of rollers 3GR and 4GR to be wound into a finished product spinning cradle FDY. The winding speed of the take-up machine was 5000 m / min, and the composite fiber 66 Den / 36f was obtained.

The elongation viscosities of nylon 6 and available polyesters at 290 ° C were 588 Pa s and 0 Pa s, respectively. The content of 5-sodiosulfoisophthalic acid as the S element was 0.3 wt% calculated from the S element, and the cross-section of the fiber was observed by SEM. As a result, the nylon 6 formed a U-shape outside the usable polyester. The fabric was obtained using all of the obtained core-sheath composite fibers and the fabric was weighed in a NaOH solution having a concentration of 1% and a bath ratio of 150 for 25 minutes. The weight loss rate of the fabric was 31.0%, the light weight ratio was 30.1 %. After dyeing the fabrics, the fastness to washing tested in JIS standard and GB standard was 4 ~ 5.

Example 2

60 wt% of nylon 6 (N6) and 40 wt% of a usable polyester chip were spinned in the same manner as in Example 1 to obtain a composite fiber 66Den / 36f.

The elongation viscosities of nylon 6 and available polyesters at 290 ° C were 688 Pa · s and 588 Pa · s, respectively, and the difference in drawing viscosity was 100 Pa · s. The content of 5-sodiosulfoisophthalic acid as the S element was 0.5 wt% calculated from the S element, and the cross-section of the fiber was observed by SEM. As a result, nylon 6 formed C type outside the usable polyester. The fabric was obtained using all of the obtained core-sheath composite fibers and the fabric was weighed in a NaOH solution having a concentration of 1% and a bath ratio of 150 for 30 minutes. The weight loss rate of the fabric was 43.0% and the light weight ratio was 41.2 %. After dyeing the fabrics, the fastness to washing tested in JIS standard and GB standard was 4 ~ 5.

Example 3

50 wt% of nylon 6 (N6) and 50 wt% of a usable polyester chip were spun in the same manner as in Example 1 to obtain a composite fiber 66Den / 36f.

The nylon 6 and the available polyester were tested at 290 ° C, respectively, and found to be 864 Pa · s and 588 Pa · s, respectively, and the difference in drawing viscosity was 276 Pa · s. The content of 5-sodiosulfoisophthalic acid as the S-element was found to be 0.4 wt% based on the element S, and the fiber cross-section was observed by SEM. As a result, the nylon 6 formed a U-shape outside the usable polyester. The fabric was obtained using all of the obtained core-sheath composite fibers and the fabric was weighed in a NaOH solution having a concentration of 1% and a bath ratio of 150 for 35 minutes. The weight loss rate of the fabric was 53.3% and the light weight ratio was 51.2 %. After dyeing the fabrics, the fastness to washing tested in JIS standard and GB standard was 4 ~ 5.

Example 4

70% by weight of nylon 66 (N6) and 30% by weight of a usable polyester chip were spun in the same manner as in Example 1 to obtain a composite fiber 66Den / 36f.

The nylon 66 and the usable polyester were tested at 290 占 폚, respectively, and found to have a tensile viscosity of 1035 Pa · s and 588 Pa · s, respectively, and a difference in drawing viscosity of 447 Pa · s. The content of 5-sodiosulfoisophthalic acid as the S element was 0.5 wt% calculated from the element S, and the cross-section of the fiber was observed by SEM. As a result, the nylon 6 formed a U-shape outside the usable polyester. The fabric was obtained using all of the obtained core-sheath composite fibers and the fabric was weighed in a NaOH solution having a concentration of 1% and a bath ratio of 150 for 25 minutes. The weight loss rate of the fabric was 32.1%, the light weight ratio was 31.5 %. After dyeing the fabrics, the fastness to washing tested in JIS standard and GB standard was 4 ~ 5.

Example 5

60% by weight of nylon 6 (N6) and 40% by weight of a usable polyester chip were spun in the same manner as in Example 1 to obtain a composite fiber 66Den / 36f.

The elongation viscosities of nylon 6 and available polyesters at 260 ° C were 1521 Pa · s and 1191 Pa · s, respectively, and the difference in drawing viscosity was 330 Pa · s. The content of 5-sodiosulfoisophthalic acid as the S element was 0.5 wt% calculated from the S element, and the cross-section of the fiber was observed by SEM. As a result, nylon 6 formed C type outside the usable polyester. The fabric was obtained using all of the obtained core-sheath composite fibers and the fabric was weighed in a NaOH solution having a concentration of 1% and a bath ratio of 150 for 30 minutes. The weight loss rate of the fabric was 43.0% and the light weight ratio was 41.2 %. After dyeing the fabrics, the fastness to washing tested in JIS standard and GB standard was 4 ~ 5.

Example 6

60% by weight of nylon 6 (N6) and 40% by weight of a usable polyester chip were spun in the same manner as in Example 1 to obtain a composite fiber 66Den / 36f.

The extruded viscosities of nylon 6 and available polyesters at 270 ° C were 1248 Pa.s and 933 Pa s, respectively, and the difference in drawing viscosity was 315 Pa s. The content of 5-sodiosulfoisophthalic acid as the S element was 0.5 wt% calculated from the S element, and the cross-section of the fiber was observed by SEM. As a result, nylon 6 formed C type outside the usable polyester. The fabric was obtained using all of the obtained core-sheath composite fibers and the fabric was weighed in a NaOH solution having a concentration of 1% and a bath ratio of 150 for 30 minutes. The weight loss rate of the fabric was 43.0% and the light weight ratio was 41.2 %. After dyeing the fabrics, the fastness to washing tested in JIS standard and GB standard was 4 ~ 5.

Example 7

60% by weight of nylon 6 (N6) and 40% by weight of a usable polyester chip were spun in the same manner as in Example 1 to obtain a composite fiber 66Den / 36f.

The elongation viscosities of nylon 6 and available polyesters at 280 ° C were 1035 Pa · s and 735 Pa · s, respectively, and the difference in drawing viscosity was 300 Pa · s. The content of 5-sodiosulfoisophthalic acid as the S element was 0.5 wt% calculated from the S element, and the cross-section of the fiber was observed by SEM. As a result, nylon 6 formed C type outside the usable polyester. The fabric was obtained using all of the obtained core-sheath composite fibers and the fabric was weighed in a NaOH solution having a concentration of 1% and a bath ratio of 150 for 30 minutes. The weight loss rate of the fabric was 43.0% and the light weight ratio was 41.2 %. After dyeing the fabrics, the fastness to washing tested in JIS standard and GB standard was 4 ~ 5.

Comparative Example 1

70 wt% of nylon 6 (N6) and 30 wt% of a usable polyester chip were spun in the same manner as in Example 1 to obtain a composite fiber 66Den / 36f.

The elongation viscosities of nylon 66 and available polyesters at 290 ° C were 528 Pa s and 588 Pa s, respectively, and the difference in drawing viscosity was -60 Pa s. The content of 5-sodiosulfoisophthalic acid as the S element was 0.5 wt% calculated from the S element, and the cross-section of the fiber was observed by SEM. As a result, nylon 6 formed C type outside the usable polyester. The fabric was obtained using all of the obtained core-sheath composite fibers and the fabric was weighed in a NaOH solution having a concentration of 1% and a bath ratio of 150 for 25 minutes. The weight loss rate of the fabric was 32.2% and the light weight ratio was 31.5 %. After dyeing the fabrics, the fastness to rinsing tested under the JIS standard was 1 to 2, and the fastness to rinsing tested under the GB standard was 1.

Item Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Comparative Example 1 Sis component N6 N6 N6 N66 N6 N6 N6 N6 Content of S element (wt%) in the available polyesters 0.3 0.5 0.4 0.5 0.5 0.5 0.5 0.5 Cis / core weight ratio 70/30 60/40 50/50 70/30 60/40 60/40 60/40 70/30 Shape component shape on fiber cross section U type C type U type U type C type C type C type C type Weight loss rate% 31.0 43.0 53.3 32.1 43.0 43.0 43.0 32.2 Lightweight rate% 30.1 41.2 51.2 31.5 41.2 41.2 41.2 31.5 Stretching viscosity measurement temperature (캜) 290 290 290 290 260 270 280 290 The stretching viscosity (Pa.s) 588 688 864 1035 1521 1248 1035 528 The stretching viscosity (Pa.s) of the usable polyester 588 588 588 588 1191 933 735 588 The difference in drawing viscosity (Pa.s) 0 100 276 447 330 315 300 -60 Wash fastness (JIS standard) 4 to 5 4 to 5 4 to 5 4 to 5 4 to 5 4 to 5 4 to 5 1 to 2 Wash fastness (GB standard) 4 to 5 4 to 5 4 to 5 4 to 5 4 to 5 4 to 5 4 to 5 1st grade

Claims (6)

In the core-sheath conjugated fiber wherein the sheath component is polyamide and the core component is the available polyester,
(M) of the polyamide in the fiber and the drawn viscosity (N) of the usable polyester satisfy the condition of MN? 0 Pa.s at the same temperature of not lower than 255 占 폚. The method according to claim 1,
Lt; RTI ID = 0.0 > 255 C < / RTI > 3. The method according to claim 1 or 2,
Wherein the weight ratio of the polyamide to the reactive polyester in the fiber is 70:30 to 30:70. 3. The method according to claim 1 or 2,
Wherein the content of 5-sodiosulfoisophthalic acid is 0.3 to 0.5 wt% of the total amount of polyester, calculated as S element among the available polyesters. 3. The method according to claim 1 or 2,
Wherein the polyamide as the sheath component is C type or U type in the cross section of the fiber. The use of said core-sheath composite fibers in fabrics of claim 1.

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