JP2007016336A - Latent-crimped polyester conjugate fiber - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a latent-crimped polyester conjugate fiber providing a stretchable woven fabric providing very good dyed quality, and having both of soft feeling with bulking, and drape with massive feeling. <P>SOLUTION: The latent-crimped polyester conjugate fiber is a conjugate fiber in which each single filament constituting a multifilament has a cross section shape obtained by cladding two kinds of polyester components having different viscosities in a side-by-side shape. The low-viscosity polyester component contains 1.5-8.0 mass% ceramic fine particles having 0.2-2.0 μm average particle diameter and ≥3.5 g/cm<SP>3</SP>density. The content of the ceramic fine particles in the high-viscosity polyester component is ≤0.5 mass%. The recovery stress of the crimp of the multifilament is ≥0.010 cN/dtex. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a latently crimped polyester composite fiber suitable for obtaining a stretch woven or knitted fabric excellent in soft texture and dyeability with a feeling of swelling, and having excellent drapeability with a feeling of weight.

  Polyesters represented by polyethylene terephthalate have excellent mechanical and chemical properties and are used in a wide range of fields. As one of the applications, in order to obtain a woven or knitted fabric having a stretch function, two types of polyesters having different heat shrinkage characteristics are joined to a side-by-side type, and the potential to develop crimp performance by heat received during processing after weaving It is well known to use crimped conjugate fibers.

  Such a fiber having latent crimpability is a fiber suitable for expressing a soft texture by imparting a bulkiness to the woven or knitted fabric by expressing crimp after weaving and knitting, giving a feeling of swelling. It is.

  On the other hand, there are applications that require a heavy feeling and drapeability of the fabric, and in recent years, there is a demand for high stretch properties in such applications. Therefore, there is a demand for a fiber that has high crimp performance and a feeling of weight, and that exhibits good drapeability when made into a fabric. However, when a conventional latent crimp yarn is made into a fabric, it is bulky. Therefore, it lacks a feeling of weight, and when crimping is manifested, there is a constraint between single yarns, and since the resistance in the shear direction increases when it is made into a fabric, it is not suitable for woven or knitted fabrics that require drapeability. Yes, the use was limited.

In order to solve the above problem, Patent Document 1 proposes a polyester composite fiber having a latent crimping performance in which ceramic fine particles are highly contained in a polyester component having a higher melt viscosity. Since this composite fiber has a high crimp performance and a feeling of weight, when it is made into a fabric, it exhibits a good feeling of swelling and drape. However, since this composite fiber contains a high amount of ceramic fine particles in the high-viscosity polyester component, a dyeing color difference may occur when dyeing, and dyed streaks may occur in the resulting fabric. .
JP 2000-345433 A

  The present invention solves the above-described problems, can produce a fabric having good dyeing quality without causing a color difference in dyeing, and has a stretchy soft texture and a heavy drape. It is an object of the present invention to provide a latent crimpable polyester composite fiber capable of obtaining a woven fabric.

  As a result of intensive studies to solve the above problems, the present inventors have reached the present invention.

That is, the present invention is a composite fiber in which each single yarn constituting the multifilament has a cross-sectional shape in which two types of polyester components having different viscosities are bonded to each other side by side, and the low-viscosity polyester component is an average. Contains 1.5 to 8.0% by mass of ceramic fine particles having a particle size of 0.2 to 2.0 μm and a density of 3.5 g / cm ³ or more, the high-viscosity polyester component has a content of ceramic fine particles of 0.5% by mass or less, and The summary is a latent crimpable polyester composite fiber characterized in that the crimp recovery stress of the filament is 0.010 cN / dtex or more.

  According to the latently crimpable polyester composite fiber of the present invention, by knitting or weaving, it has a soft texture with a feeling of swelling, has a heavy drape, and has excellent dyeing quality. A woven or knitted fabric can be obtained, and is particularly suitable for apparel applications.

  Hereinafter, the present invention will be described in detail.

  The latent crimpable polyester composite fiber (hereinafter simply referred to as a composite fiber) of the present invention is composed of two types of polyester components having different viscosities, and the polyester component has an ethylene terephthalate repeating unit of 90% or more. It is preferably substantially composed mainly of polyethylene terephthalate (PET).

  The two types of polyesters having different viscosities preferably exhibit a difference in melt viscosity at the time of spinning in order to develop crimp when formed into fibers, and the difference in melt viscosity between the high viscosity polyester component and the low viscosity polyester component is: When measured under the conditions of a temperature of 280 ° C. and a shear rate of 1000 / S, it is preferably 100 poise or more, and more preferably a difference of 500 to 1500 poise in order to develop sufficient crimp.

  If the difference in melt viscosity between the two polyester components is less than 100 poise, the heat shrinkability of both components is approximated, and the desired crimping performance may not be sufficiently exhibited, which is not preferable. On the other hand, if the difference in melt viscosity between the two polyester components exceeds 1500 poise, the spinning operability tends to be lowered, and the dyeing color difference is likely to occur, which may lower the dyeing quality.

  As described above, in order to provide a difference in viscosity between the two polyester components, the high-viscosity polyester component needs to have higher heat shrinkability than the low-viscosity polyester component. Good. For example, as copolymerization components, dicarboxylic acid components such as isophthalic acid, 5-sodium sulfoisophthalic acid, naphthalene dicarboxylic acid, adipic acid, 1,4-butanediol, propylene glycol, diethylene glycol, 1,4-cyclohexanedimethanol, etc. Examples thereof include a diol component and an EO adduct of bisphenol A.

  In addition, both polyester components contain small amounts of other components such as matting agents, antioxidants, UV absorbers, pigments, flame retardants, antibacterial agents, and conductivity-imparting agents, as long as the essential properties are not impaired. It may be.

  The degree of polymerization of these two types of polyester components can be selected from the range used for ordinary melt spinning, and those having an intrinsic viscosity in the range of 0.4 to 0.8 are preferred.

The low-viscosity polyester component has an average particle size in the range of 0.2 to 2.0 μm and contains 1.5 to 8.0% by mass of ceramic fine particles having a density of 3.5 g / cm ³ or more, and more preferably 1.5 to 6.0% by mass. Is preferred.

  By containing these fine particles, the weight feeling of the fiber is increased, and at the same time, the fine particles are partially exposed on the fiber surface, thereby reducing the surface frictional resistance. It becomes possible to express a good drape feeling.

  When both of the polyester components contain a large amount of fine particles in a high-viscosity polyester component whose orientation is further promoted, the frequency of occurrence of secondary condensation of the fine particles increases. It is easy to generate | occur | produce and the quality of the fabric using this fiber will fall easily. Therefore, by incorporating fine particles into the low-viscosity polyester component, the physical properties are governed (specified) by the high-viscosity polyester component, and by suppressing secondary condensation of the fine particles with the low-viscosity polyester component, strength, elongation, etc. A fiber having stable physical properties and stable dyeing quality can be obtained.

  The ceramic fine particles used in the present invention are those obtained by atomizing a nonmetallic inorganic material obtained through processes such as molding and firing, and are typically inorganic oxide fine particles such as titanium oxide and silicon oxide. From the viewpoint of operation and quality, it is preferable that the surface tension at the interface with the material is small and hardly aggregates at the time of melting.

  The ceramic fine particles are required to have an average particle size in the range of 0.2 to 2.0 μm. The average particle size means that after finely dispersing ceramic fine particles in an ethylene glycol solution, using a laser diffraction particle size distribution analyzer SALD-2000J manufactured by Shimadzu Corporation, volume distribution standard conversion, refractive index 1.70-0.20i The measurement is performed under the following conditions.

  When the ceramic fine particles having an average particle diameter in this range are partially exposed on the fiber surface, the fiber surface slips better. If the average particle size is smaller than this range, the effect of modifying the fiber surface is poor. On the other hand, if it is larger than this range, the particles are locally exposed to a large extent, resulting in an increase in frictional resistance. Further, since the particles are localized, yarn breakage occurs due to stress bias during spinning, Operational problems such as fluffing occur.

Further, the density of the ceramic fine particles is 3.5 g / cm ³ or more. If the density is lower than 3.5 g / cm ^{3, the} effect of increasing the density of the fiber is poor, and if it is included in a large amount to increase the density, yarn breakage may occur during spinning, fluffing may occur during stretching, processing, etc. There is a problem in operability, which is not preferable. The upper limit of the density of the ceramic fine particles is not particularly limited, but is preferably about 5.0 g / cm ^{3 in} consideration of trouble due to aggregation and operability.

  Next, the content of the ceramic fine particles is 1.5 to 8.0 mass%, preferably 1.5 to 6.0 mass%, based on the total mass of the low-viscosity polyester component. When the content is less than 1.5% by mass, the effect of imparting a feeling of weight and reducing surface friction becomes poor. On the other hand, when the content exceeds 8.0% by mass, yarn breakage and fluff are likely to occur during spinning and drawing, resulting in a fiber having a deteriorated quality, and the dyed quality of the obtained fabric is also inferior.

  The ceramic fine particles can be added at the time of melting the polyester during polymerization or spinning, but it is preferable to add at the time of polymerization in consideration of preventing aggregation and dispersing more uniformly.

  The high-viscosity polyester component may contain a small amount of ceramic fine particles similar to the low-viscosity polyester component, but the content is 0.5% by mass or less. If it exceeds 0.5% by mass, aggregation of ceramic fine particles is likely to occur in the high-viscosity polyester component, resulting in a dyeing color difference.

  The composite fiber of the present invention has a crimp recovery stress of 0.010 cN / dtex or more, and preferably 0.015 to 0.020 cN / dtex. When the crimp recovery stress is less than 0.010 cN / dtex, the crimp development performance is inferior, and even if crimps are developed after forming the fabric, a fabric having poor stretchability is obtained. On the other hand, when the crimp recovery stress exceeds 0.020 cN / dtex, when trying to obtain such a yarn, the spinning operability deteriorates, and the dyeability tends to decrease.

  The crimp recovery stress in the present invention is obtained by staking a multifilament (fiber) 5 times with a measuring machine having an outer circumference of 1 m, making it double, and applying a load of 1/6800 cN / dtex for 30 minutes. After 30 minutes of boiling water treatment and drying, the tensile speed of the universal tensile tester Tensilon RTC1210 manufactured by Orientec Co., Ltd. was increased to 100 mm / min, and the sample was stretched to a stress of (fineness x 2) cN and recovered at the same speed. A perpendicular is drawn from the maximum stress point at the time, and the stress measurement value at the intersection of the stress recovery curve and the line drawn to the stress curve side at an angle of 45 degrees from the intersection with the stress 0 cN line is read.

  Both polyester components exhibit a shape bonded to the side-by-side type in a cross-sectional shape cut perpendicularly to the longitudinal direction of the composite fiber, but the joint surfaces of both polyester components may be linear shapes, It may have a curved shape.

  And the composite ratio of both polyester components is preferably in the range of 40/60 to 60/40 in mass ratio in order to obtain good crimping performance. If it is out of this range, sufficient crimping performance may not be exhibited, which is not preferable.

  The composite fiber of the present invention preferably has a single yarn fineness of 1 to 10 dtex and a single yarn number of 5 to 100, and it is preferable to select appropriately in accordance with the application within these ranges.

  Next, the manufacturing method of the composite fiber of this invention is demonstrated. The conjugate fiber of the present invention can be produced by a usual conjugate spinning type melt spinning machine. First, both polyester components are merged to form a side-by-side type on the back surface of the spinneret, and discharged from the same spinning hole for spinning. In this case, the spinning temperature is appropriately selected depending on the melt viscosity of both polyester components, but is usually preferably in the range of 280 to 310 ° C. The spinning yarn is cooled and solidified, and then a spinning oil is applied and taken up at a speed of 1000 to 4000 m / min. Thereafter, the composite fiber of the present invention can be obtained by winding it once and subjecting it to hot drawing by a drawing machine, or by drawing the taken yarn continuously after spinning.

  The draw ratio in the above production method is preferably selected as appropriate depending on the residual elongation of the fiber at the time of drawing, and is preferably selected so that the residual elongation after drawing is in the range of 15 to 40%. If the residual elongation is higher than this range, sufficient crimping performance will not be expressed, and if the residual elongation is lower than this range, there is a problem in operation such as the occurrence of single yarn breakage during drawing, which is preferable. Absent.

Next, the present invention will be specifically described with reference to examples. In addition, the measuring method and evaluation method of the physical property in an Example are as follows.
(a) Melt viscosity Measured using a flow tester CFT-500 manufactured by Shimadzu Corporation under conditions of a temperature of 280 ° C. and a shear rate of 1000 / S.
(b) Crimp recovery stress Measured by the method described above.
(c) Evaluation of stretch property, drape property, and dyeing quality The resulting composite fiber (56dtex / 48f, 56dtex / 12f) was subjected to 1100 T / M twist (S twist, twist coefficient K11000), followed by 80 ° C, 40 Vacuum heat setting was performed under the condition of minutes. Using this yarn as the weft, using a warp yarn of 110 dtex / 24 filament PET, weaving a plain weave fabric with a warp density of 78 / 2.54 cm and a weft density of 57 / 2.54 cm, and dyeing under the following conditions Went.
The obtained fabric was subjected to sensory evaluation by 10 panelists. Each performance was evaluated in 10 stages (10 is the most excellent), and an average value of 10 of these evaluation values was obtained and evaluated in the following 4 stages. ◎ and ○ were accepted.
◎ Very good: Average value is 8 points or more ○ Good: Average value is 6 points to less than 8 points Δ Slightly inferior: Average value is 5 points to less than 6 points × Inferior: Average value is less than 5 points Dianix Blue UN-SE (1% omf) was used, and staining was performed at a bath ratio of 1:20 and 130 ° C. for 30 minutes. At this time, the relaxation condition was 130 ° C. × 30 minutes (liquid flow dyeing machine), the preset condition was 190 ° C. × 40 seconds, and the final set condition was 170 ° C. × 30 seconds.

Example 1
As a high-viscosity polyester component, titanium dioxide fine particles with a density of 3.9 g / cm ³ and an average particle diameter of 0.7 μm are added during polymerization, and a PET with a melt viscosity of 2200 poise with a content of titanium dioxide fine particles of 2.0 mass% is used. It was. As the low-viscosity polyester component, PET having a melt viscosity of 1700 poise containing 0.3% by mass of titanium dioxide fine particles similar to the high-viscosity polyester component was used.
Equal mass of both polyester components are fed to a compound spinning type melt extruder, melted at a spinning temperature of 295 ° C, and both components are merged at the back of a spinneret with 24 spinning holes, and joined to a side-by-side mold for spinning. After cooling and solidification, the yarn was collected while applying a spinning oil agent, and was wound off by a take-off machine through a take-up roller having a surface speed of 3250 m / min.
Next, the obtained fiber was supplied to a drawing machine and drawn 1.47 times through a roller having a surface temperature of 85 ° C. and a hot plate having a temperature of 165 ° C. to obtain a composite fiber of 110 dtex / 24 filament.

Examples 2-6, Comparative Examples 1-5
A composite fiber was obtained in the same manner as in Example 1 except that the melt viscosity of both polyester components and the content of titanium dioxide fine particles of the low viscosity polyester component were variously changed as shown in Table 1.

  Table 1 shows the evaluation results of the composite fibers and fabrics obtained in Examples 1 to 6 and Comparative Examples 1 to 5.

  As is apparent from Table 1, the composite fibers of Examples 1 to 6 all have high crimp recovery stress, and the fabric obtained from these fibers has high stretchability, excellent dyeing quality, and good drapeability. It was something that had both.

On the other hand, since the conjugate fiber of Comparative Example 1 has no difference in viscosity between the two polyester components, there was no crimp recovery stress, and the resulting woven fabric was poor in stretchability. Since the composite fiber of Comparative Example 2 has a small content of ceramic fine particles (titanium dioxide fine particles), the resulting fabric lacked drapeability. Moreover, since the composite fiber of Comparative Example 3 had a large content of titanium dioxide fine particles, fluff frequently occurred during stretching, and the resulting woven fabric was inferior in dyeing quality. Since the conjugate fiber of Comparative Example 4 did not contain ceramic fine particles, the resulting fabric had poor drapeability. Furthermore, since the conjugate fiber of Comparative Example 5 contained titanium dioxide fine particles in a high-viscosity polyester component, the resulting fabric had a dyeing color difference and was inferior in dyeing quality.

Claims (2)

Each single yarn constituting the multifilament is a composite fiber having a cross-sectional shape in which two types of polyester components having different viscosities are bonded to each other side by side, and the low-viscosity polyester component has an average particle size of 0.2 to 2.0. It contains 1.5 to 8.0% by mass of ceramic fine particles with μm and density of 3.5g / cm ³ or more, high viscosity polyester component contains 0.5% by mass or less of ceramic fine particles, and crimp recovery stress of multifilament A latent crimpable polyester composite fiber characterized by having a crease of 0.010 cN / dtex or more. The latent crimpable polyester composite fiber according to claim 1, wherein a difference in melt viscosity (measured at a temperature of 280 ° C and a shear rate of 1000 / S) between the low viscosity polyester component and the high viscosity polyester component is 500 to 1500 poise.