JP4783068B2 - Polyester composite fiber - Google Patents

Description

  The present invention is a composite fiber having a single yarn shape in which two types of polyester components having different viscosities are bonded together, and has a latent crimping performance, so that it has excellent stretch back properties when formed into a woven or knitted fabric. The present invention relates to a polyester composite fiber that has a firmness and stiffness, and that can obtain a fabric having a good quality without swelling and texture.

  Polyesters represented by polyethylene terephthalate have excellent mechanical and chemical properties and are used in various applications in the fiber field. As one of these applications, in order to obtain a woven or knitted fabric having stretch performance, two types of polyesters with different heat shrinkage characteristics are joined to the side-by-side type, and crimp performance is expressed by the heat received during processing after weaving and knitting. The composite fiber which has the latent crimp property which is used is used (for example, refer patent document 1, 2).

  Such a latently crimped fiber becomes bulky when it develops crimps after weaving and knitting, can give the woven or knitted fabric a feeling of swelling, and can also impart stretch performance and a soft texture. These latently crimpable fibers can be used alone after being processed into a woven or knitted fabric, but they can also be combined and used as processed yarns by mixing or entanglement with other various fibers, and combined. It becomes possible to give the above-mentioned performance while taking advantage of the properties of the partner fiber, and it is used for many purposes.

In recent years, there has been a growing demand for composites of such fiber materials, and in addition to the above-described performance, there is a demand for latent crimpable fibers that can obtain a higher-quality fabric.
Japanese Patent Laid-Open No. 11-241229 JP 2000-212838 A

  The present invention solves the above-mentioned problems, can give excellent stretch back properties, firmness and stiffness when made into a woven or knitted fabric, and also has a good quality with no wrinkles in addition to the feeling of swelling. The polyester composite fiber which can obtain the fabric of this is provided.

  The inventors of the present invention have arrived at the present invention as a result of intensive studies to solve the above problems.

That is, the present invention comprises 2,2-bis {4- (Β-hydroxyethoxy) phenyl} propane and a sulfonic acid base compound or isophthalic acid component in a total amount of 5 to 20 mol% and a high viscosity polyester component and ethylene terephthalate. A composite fiber satisfying the following (1) in which a low-viscosity polyester component as a main repeating unit is bonded to each other in a side-by-side type or an eccentric core-sheath type, satisfying the following (1), and spirally crimped by boiling water treatment And the number of crimps (Y) of spiral crimps developed by boiling water treatment at 100 ° C. for 15 minutes is 20 peaks / cm or more, and the crimp rate (X) and is the ratio (X / Y) is 1.5 or less, and abstracts a polyester composite fiber characterized by fineness is 0.7~1.5dtex Is shall.
(1) 0.05 ≦ [η] A− [η] B ≦ 0.30
However, [η] A is the intrinsic viscosity of the high viscosity polyester component, and [η] B is the intrinsic viscosity of the low viscosity polyester component .

  The polyester conjugate fiber of the present invention can give excellent stretch back properties, elasticity and stiffness when it is made into a woven or knitted fabric, and furthermore, it can obtain a fabric of good quality that has no wrinkles in addition to a feeling of swelling. Is possible.

  Hereinafter, the present invention will be described in detail.

  The conjugate fiber of the present invention is a conjugate fiber having a single yarn shape in which two types of polyester components (high viscosity polyester component and low viscosity polyester fiber) having different viscosities are bonded to each other in a side-by-side type or an eccentric core-sheath type. is there.

  That is, each single yarn constituting the composite fiber is a cross-sectional shape in which two types of polyester components are bonded to a side-by-side type or an eccentric core-sheath type. The side-by-side type refers to FIG. As shown in Fig. 1, there are two types of polyester components that are bonded together in a straight line, and the bonded surfaces are bonded almost equally, and those in which the bonded surfaces are curved and bonded as shown in Fig. 1 (B). Can be mentioned. As shown in FIG. 2, the eccentric core-sheath type means that one component is a sheath and the other component is a core, and the centers of the core portion and the sheath portion do not coincide. In the present invention, the sheath part is preferably a high viscosity component and the core part is preferably a low viscosity component.

  In the conjugate fiber of the present invention, the difference between the intrinsic viscosity [η] A of the high-viscosity polyester component and the intrinsic viscosity [η] B of the low-viscosity polyester component ([η] A− [η] B) is 0.05 to 0.3 is preferable, and 0.07 to 0.25 is particularly preferable.

  Here, the intrinsic viscosity is a value measured at 20 ° C. using a Ubbelohde viscometer after dissolving polyester in a 1: 1 mixed solvent of phenol and tetrachloroethane.

  When [η] A- [η] B is less than 0.05, the expression of crimping performance tends to be insufficient, and it becomes difficult to obtain a fabric having a sufficient swell feeling and stretch performance. On the other hand, when [η] A- [η] B exceeds 0.3, bending is increased when a composite stream of both polyesters is discharged from the spinneret, and the spun polymer (yarn) becomes the spinneret. It tends to be difficult to carry out stable spinning by causing adhesion and cutting.

The high-viscosity polyester component is mainly composed of polyethylene terephthalate (hereinafter, abbreviated as PET) having ethylene terephthalate as a main repeating unit, and the ethylene terephthalate repeating unit may be a PET having 90% or more. preferable. And it is necessary for PET to contain 2,2-bis {4- (Β-hydroxyethoxy) phenyl} propane and a sulfonate group compound or an isophthalic acid component.

By containing 2,2-bis {4- (Β-hydroxyethoxy) phenyl} propane and a sulfonate group compound or an isophthalic acid component , the high-viscosity polyester component has a high thermal shrinkage rate, and the low-viscosity polyester component It is possible to increase the difference in heat shrinkage ratio between the fibers, and as a result, it is possible to increase the latent crimp ratio of the entire fiber. In other words, it is possible to increase the latent crimp rate without increasing the intrinsic viscosity difference between the high-viscosity polyester component and the low-viscosity polyester fiber. Can be produced with good operability.

The total content of 2,2-bis {4- (B-hydroxyethoxy) phenyl} propane, sulfonate group compound and isophthalic acid needs to be in the range of 5 to 20 mol% in the high viscosity polyester component. In particular , it is preferably 6 to 15 mol%. In order to contain these components, it is preferable that they are copolymerized with PET, but they may be blended (mixed).

  If the content is less than 5 mol%, a sufficient effect of improving the latent crimp performance cannot be obtained. On the other hand, if the content exceeds 20 mol%, the spinnability is impaired or the fiber strength is impaired. It is not preferable.

  Among them, 2,2-bis {4- (B-hydroxyethoxy) phenyl} propane is preferably contained in the high-viscosity polyester component in an amount of 2 mol% or more because it has a large effect of improving heat shrinkability. It is preferable to contain more than mol%.

  As the sulfonate group compound, 5-sodium sulfoisophthalic acid is particularly preferable. The content of the sulfonate group compound is preferably 1 mol% or more, and the content of isophthalic acid is preferably 2 mol% or more.

  The low-viscosity polyester component that constitutes the conjugate fiber of the present invention is not particularly limited as long as it is mainly composed of PET, but it should be a PET in which the repeating unit of the ethylene terephthalate component is 95% or more. Is preferred. In order to make the heat shrinkability lower than that of the high-viscosity polyester component, those containing components that greatly inhibit crystallinity, or 2,2-bis {4- (B- Those containing hydroxyethoxy) phenyl} propane, sulfonate group compounds, isophthalic acid and the like are not preferred.

  In addition, both polyester components contain a small amount 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. You may do it.

  Furthermore, the ratio of both polyester components in the composite fiber is preferably in the range of 40/60 to 60/40 by mass ratio. By setting it within this range, the number and size of crimps developed by post-processing are sufficient, and excellent latent crimpability can be obtained.

Next, the single yarn fineness of the composite fiber of the present invention needs to be 0.7 to 1.5 dtex. If the single yarn fineness exceeds 1.5 dtex , the resulting fabric tends to be inferior in softness. On the other hand, if the single yarn fineness is less than 0.7 dtex , the expression of crimping performance tends to be insufficient, and it tends to be difficult to obtain a fabric having sufficient swell and stretch performance. The yarn tends to adhere to the spinneret at the time of spinning, and it is difficult to perform stable spinning. By setting it to 0.7 to 1.5 dtex, it is possible to obtain a fabric having both a soft feeling and a swelled feeling that are not conventionally provided, and it is possible to obtain fibers with good operability.

  The composite fiber of the present invention has a latent crimping performance that develops spiral crimps by boiling water treatment, and the number of crimps (Y) of spiral crimps that emerges by boiling water treatment at 100 ° C. for 15 minutes. It is 20 peaks / cm or more, and the ratio (X / Y) to the crimp rate (X) is 1.5 or less.

  That is, the conjugate fiber of the present invention expresses a spiral crimp by boiling water treatment, and the spiral crimp refers to a crimp that has a three-dimensional spiral structure. And the number of crimps (Y) of the spiral crimp which develops by boiling water treatment for 15 minutes at 100 ° C. is 20 peaks / cm or more, and preferably 25-40 peaks / cm.

  If the number of crimps (Y) is less than 20 peaks / cm, the resulting fabric will have poor stretch-back properties, elasticity and stiffness, making it difficult to obtain a fabric having sufficient performance. In addition, being excellent in stretch-back property means that the recovery speed when instantaneously returning to the original dimension immediately after releasing the stress after applying the stress to the fabric and stretching is high.

  Further, the number of crimps (Y) (mountain / cm) after boiling water treatment in the present invention is determined by the following method. First, the fiber is cut to a length of 7 cm to make a sample, immersed in boiling water in a free state, and subjected to boiling water treatment at 100 ° C. for 15 minutes. After the treatment, the fiber is taken out and immediately immersed in water at 20 ° C. for 1 minute. Thereafter, the fiber is taken out and naturally dried for 5 hours in a free state. After the drying, when the fiber is applied to the sample plate, the fiber is stretched to a length twice as long as measured in a free state, covered with a slit plate having a width of 2 cm, and observed with a microscope, and the number of peaks is read. Measurement is performed twice with one sample, 10 samples are measured, and an average of these measured values (n = 20) is obtained.

  Furthermore, the ratio (X / Y) of the number of crimps (Y) to the crimp rate (X) is 1.5 or less, and preferably 1.0 or less.

  In the present invention, the number of crimps (Y) is set to 20 or more and X / Y is set to 1.5 or less, whereby the resulting fabric is excellent in stretch back property, and has a smooth and high-quality surface quality. Can be obtained. When X / Y exceeds 1.5, since the number of crimps is small with respect to the crimping rate, the surface state of the resulting fabric cannot obtain a smooth surface feeling, and the surface quality is inferior.

The crimp rate (X) (%) after boiling water treatment in the present invention is determined by the following method. The fiber that has been cut 10 times with a measuring scale is immersed in boiling water in a free state and subjected to boiling water treatment at 100 ° C. for 30 minutes. After the treatment, the fiber having a length a is taken out, air-dried for 30 minutes in a free state, a length b is measured by applying a load of 2.27 × 10 ⁻³ cN / dtex, and calculated from the following formula.
Crimp rate (X) (%) = [(ba) / b] × 100

  The polyester composite fiber of the present invention preferably has a boiling water shrinkage of 3 to 12%. By setting the boiling water shrinkage to 3 to 12%, the obtained fabric is excellent in soft feeling in addition to the above-mentioned texture. When the boiling water shrinkage rate exceeds 12%, the resulting fabric shrinks so that the coarse and rigid feeling becomes obvious and the soft feeling tends to be poor. On the other hand, if the boiling water shrinkage is less than 3%, the resulting fabric tends to have poor swell and stretch back properties.

In addition, the boiling water shrinkage rate in this invention is calculated | required with the following method. A load of 0.18 cN / dtex is applied to the fiber that has been cut 10 times with a measuring instrument, and the original length L0 is measured. Next, the load is removed, a load of 1/6000 cN / dtex is applied and immersed in boiling water, and boiling water treatment is performed at 100 ° C. for 15 minutes. After the treatment, the fiber is taken out and immediately immersed in water at 20 ° C. for 1 minute. Thereafter, the fiber is taken out and naturally dried for 5 hours in a free state. After drying, apply a load of 3.5 cN / dtex to the fiber, wait 30 seconds, measure the length L1 after treatment, and obtain the boiling water shrinkage from the following formula.
Boiling water shrinkage (%) = [(L0−L1) / L0] × 100

  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, on the back of the spinneret, two types of polyester components are merged into a side-by-side type or an eccentric core-sheath type, discharged from the same spinning hole, and spun. In this case, the spinning temperature is appropriately selected depending on the intrinsic viscosity of the polyester component, but is usually preferably in the range of 280 ° C to 310 ° C. The spun yarn is cooled and solidified, then applied with a spinning oil agent, taken up at a speed of 1000 to 4000 m / min, taken up once, and then subjected to heat drawing by a drawing machine in a separate process, or taken up yarn The composite fiber of the present invention can be obtained by hot drawing continuously after spinning without stripping the strip once. The draw ratio in the above production method is appropriately selected 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%.

  And although the composite fiber of this invention can be used as a warp and a weft as it is, you may mix and use with other yarn. Moreover, a false twist process may be given and a false twist mixed fiber may be sufficient. Moreover, a real twist may be given, a real twist mixed fiber may be sufficient, and what combined these may be sufficient.

  The conjugate fiber of the present invention exhibits latent crimping performance by boiling water treatment. However, in consideration of workability such as process passability, it is made into a fabric by weaving or the like, and then subjected to boiling water treatment to perform latent crimping. It is preferable to develop performance. Among these, it is preferable to express in the alkali weight loss treatment step or the dyeing step.

Hereinafter, the present invention will be described more specifically with reference to examples. In the examples, measurement and evaluation were performed as follows.
(1) Intrinsic viscosity It was measured by the method described above.
(2) Fabric texture The obtained composite fiber (56dtex / 48f, 56dtex / 12f) is subjected to 1500 T / M twisting (S twist, twisting coefficient K11000), followed by vacuum heat setting at 80 ° C for 40 minutes. went. Weaving a plain weave fabric with a warp density of 110 / 2.54cm and a weft density of 80 / 2.54cm using this yarn as warp and weft, and after scouring, it is treated in boiling water at 100 ° C for 15 minutes to reduce latent crimps. It was allowed to develop and then air-dried to obtain a woven fabric. The composite fiber obtained was 110dtex / 24f. Same as above except that it was twisted at 1100T / M and changed to a plain weave with a warp density of 78 / 2.54cm and a weft density of 57 / 2.54cm. A woven fabric was obtained.
The obtained woven fabric was evaluated by touch using a panel. Each of stretch back property, surface quality (smoothness without wrinkles), soft feeling, elasticity and stiffness was evaluated in 10 grades of 1 to 10 points (10 points were the best).

Examples 1-2 and Comparative Examples 1-7
As a high viscosity polyester component, 2,2-bis {4- (Β-hydroxyethoxy) phenyl} propane (hereinafter referred to as BP-A / EO), isophthalic acid (IPA), 5-sodium sulfoisophthalic acid ( A copolymerized PET having a SIP content (copolymerization amount) shown in Table 1 and having the intrinsic viscosity shown in Table 1 was used. As the low viscosity polyester component, PET having the intrinsic viscosity shown in Table 1 was used.
Equal amounts of both polyester components were fed to a compound spinning type melt extruder, melted at a spinning temperature of 295 ° C., both components were merged at the back of a spinneret having a spinning hole, joined to a side-by-side mold, and spun. After spinning and solidifying the spun yarn, the yarn was converged while applying an oil agent, and was taken up with a take-up machine through a take-up roller having a surface speed of 3000 m / min.
Next, the obtained fiber was supplied to a drawing machine, drawn at a draw ratio of 1.6 times through a roller having a surface temperature of 85 ° C. and a hot plate having a temperature of 170 ° C., and wound up.
The obtained conjugate fiber exhibited a cross-sectional shape of the bonded surface shown in FIG. 1 (B), and each filament configuration was as shown in Table 1.

  Table 1 shows the crimped number Y, crimped rate / crimped number (X / Y), boiling water shrinkage rate, and fabric texture evaluation results of the obtained composite fiber.

As is clear from Table 1, the composite fibers of Examples 1 and 2 were obtained because the crimp number Y, the crimp rate / crimp number (X / Y), and the boiling water shrinkage rate were appropriate values. The obtained fabric was excellent in stretch back property, surface quality, softness, and elasticity.
On the other hand, since the composite fibers of Comparative Examples 1 to 4 had a single yarn fineness outside the range of 0.7 to 1.5 dtex, the obtained fabric was inferior in soft feeling and surface quality. Since the composite fibers of Comparative Examples 5 and 6 had a crimp number Y of less than 10 and a crimp ratio / crimp number (X / Y) of more than 1.5, the stretch back property, surface quality, Both were inferior. Moreover, since the conjugate fiber of Comparative Example 7 had a crimp ratio / crimp number (X / Y) of more than 1.5, the resulting fabric was inferior in surface quality.

It is a cross-sectional schematic diagram of the single fiber which shows one embodiment (side-by-side type) of the composite shape of the composite fiber of this invention. It is a cross-sectional schematic diagram of the single fiber which shows one embodiment (eccentric core-sheath type) of the composite shape of the composite fiber of this invention.

Claims (1)

2,2-bis {4- (Β-hydroxyethoxy) phenyl} propane and a sulfonate group compound or isophthalic acid component in a total amount of 5 to 20 mol%, a high viscosity polyester component and ethylene terephthalate as a main repeating unit A latently crimped composite fiber that satisfies the following (1), which has a single yarn shape in which the viscosity polyester components are bonded to each other in a side-by-side type or an eccentric core-sheath type, and exhibits a spiral crimp by boiling water treatment The number of crimps (Y) of the spiral crimps produced by boiling water treatment at 100 ° C. for 15 minutes is 20 peaks / cm or more, and the ratio to the crimp rate (X) (X / A polyester composite fiber characterized in that Y) is 1.5 or less and the single yarn fineness is 0.7 to 1.5 dtex .
(1) 0.05 ≦ [η] A− [η] B ≦ 0.30
However, [η] A is the intrinsic viscosity of the high viscosity polyester component, and [η] B is the intrinsic viscosity of the low viscosity polyester component.