JP2011026762A - High shrinkage fiber - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high shrinkage fiber exhibiting high shrinkage in boiling water, and providing high density when used for a woven fabric. <P>SOLUTION: The high shrinkage fiber includes a nylon MXD6 polymer and a nylon 6 polymer in a weight ratio of 35:65 to 70:30, and has a breaking strength of >4.00 cN/dtex. In a preferable embodiment, the weight ratio of the nylon MXD6 polymer to the nylon 6 polymer is 45:55 to 55:45. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a highly shrinkable fiber having high shrinkage performance and capable of obtaining a high density when used as a woven fabric.

  In recent years, in the development of high-density fabrics, there has been a demand for fibers that exhibit high shrinkage performance by heat treatment. And, when heat treatment is applied to a woven fabric made of such highly shrinkable fibers, the highly shrinkable fibers contract, thereby clogging the eyes between the warp and the weft, and providing appropriate elasticity, stiffness and resilience. A high-density woven fabric can be obtained.

  As such a highly shrinkable fiber, a highly shrinkable polyester filament is used, but the texture after shrinkage is hard, and there is a problem in comfort as a clothing application.

  Japanese Patent Laid-Open No. 3-64516 discloses a highly shrinkable nylon fiber having a boiling water shrinkage of 15% or more. However, this fiber is for blending with other fibers to make a different shrinkage mixed yarn, and even if heat treated to the woven fabric of this fiber, the shrinkage stress is small, so it does not shrink sufficiently, A high density fabric could not be obtained.

  JP-A-8-209444 discloses a highly shrinkable nylon fiber having a boiling water shrinkage of 30% or more. However, since the polymer used for producing the fiber is produced by copolymerization, there is a problem that it takes time and effort to produce the copolymer and the cost is increased.

Japanese Patent Laid-Open No. 3-64516 JP-A-8-209444

  The present invention has been made in order to solve the disadvantages of the prior art, and an object of the present invention is to provide a highly shrinkable fiber which has a high boiling water shrinkage ratio and can obtain a high density when used as a woven fabric. And

  In order to achieve the above object, the present invention is a fiber made of nylon MXD6 polymer and nylon 6 polymer, each having a weight ratio of 35:65 to 70:30 and a breaking strength of 4.00 cN / dtex or more. The first aspect is a highly shrinkable fiber characterized by the above. Nylon MXD6 referred to here is a crystalline polyamide obtained from a polymerization reaction of metaxylenediamine and adipic acid.

  Moreover, as a preferable aspect of the present invention, there may be mentioned those having a weight ratio of nylon MXD6 polymer to nylon 6 polymer of 45:55 to 55:45 in the high shrinkage fiber.

The highly shrinkable fiber of the present invention exhibits high shrinkage performance when nylon MXD6 polymer and nylon 6 polymer are mixed in a weight ratio of 35:65 to 70:30, respectively. Moreover, since moderate intensity | strength is hold | maintained, weaving property is favorable and it has the high tearing strength as a textile fabric. Furthermore, it has a good texture not found in polyester high-density fabrics.

  In addition, since a polymer mixture is used instead of copolymerization, a copolymerization step is not required, and labor and cost for copolymerization can be reduced.

  Among the highly shrinkable fibers of the present invention, those having a weight ratio of nylon MXD6 polymer and nylon 6 polymer of 45:55 to 55:45, respectively, have a particularly high boiling water shrinkage ratio. When applied, it makes it possible to obtain a higher density fabric.

Hereinafter, the present invention will be described in detail.
The polymer mixture used in the present invention needs to be a mixture of nylon MXD6 polymer and nylon 6 polymer in a weight ratio of 35:65 to 70:30, respectively. Using this as a raw material, highly shrinkable fibers can be obtained. If the nylon MXD6 polymer is less than 35% by weight or more than 70% by weight, a fiber having a high boiling water shrinkage cannot be obtained.

  The polymer mixture used in the present invention particularly preferably has a weight ratio of nylon MXD6 polymer to nylon 6 polymer of 45:55 to 55:45. If the weight ratio is 45:55 to 55:45, since the boiling water shrinkage (%) is particularly large, a higher-density fabric can be obtained.

  The nylon 6 polymer preferably has a relative viscosity of 2.2 or more from the viewpoint of stable operability of melt spinning. More preferably, the relative viscosity is 2.4 or more, and particularly preferably the relative viscosity is 2.7 or more. The upper limit of the relative viscosity is not particularly limited, but up to 3.5 is sufficient from the viewpoint of stable operability of melt spinning.

  The nylon MXD6 polymer preferably has a relative viscosity of 2.1 or more from the viewpoint of stable operability of melt spinning. More preferably, the relative viscosity is 2.3 or more, and particularly preferably the relative viscosity is 2.5 or more. The upper limit of the relative viscosity is not particularly limited, but up to 3.3 is sufficient from the viewpoint of stable operability of melt spinning.

  The moisture content (ppm) of the nylon 6 polymer and nylon MXD6 polymer is not particularly limited and can be determined as appropriate. From the viewpoint of spinning operability, it is preferable to use one having a water content of 500 ppm or less during spinning. More preferably, it is 300 ppm or less, Most preferably, it is 200 ppm or less.

  The polymer preferably contains inorganic particles in order to improve spinning operability. There are many inorganic particles for this purpose, and examples include titanium oxide, zinc oxide, magnesium carbonate, silicon oxide, calcium carbonate, and alumina. If there is no problem in spinning operability, the inorganic particles to be added are not particularly limited, but titanium oxide is preferably used from the viewpoint of dispersibility and cost performance. It is preferable to add inorganic particles in an amount of 0.1% to 3.0% by weight, particularly preferably 0.3% to 1.0% by weight, based on the yarn weight.

  When the inorganic particles are used, the average particle size of the powder or particles is preferably 0.01 μm to 10 μm, particularly preferably 0.05 μm to 2 μm. Within this range, the particles are less likely to agglomerate, so that yarn unevenness is less likely to occur and a stable strength can be obtained.

The mixing method of nylon 6 polymer and nylon MXD6 polymer is not particularly limited. For example, nylon 6 polymer and nylon MXD6 polymer chips may be mixed or kneaded in a container.

  The spinning method and the twisting method for obtaining the fiber of the present invention are not particularly limited. After spinning by the conventional method, it is possible to appropriately determine a twisting method, a spinning direct drawing method, or the like. Also, the stretching method is not particularly limited, and can be appropriately determined such as single-stage stretching or multi-stage stretching.

  The spinning conditions can be appropriately determined from the viewpoint of the relative viscosity of the polymer and the operability. The following example is introduced as an example. A nylon 6 polymer having a relative viscosity of 3.0 and a nylon MXD6 polymer having a relative viscosity of 2.7 are mixed to produce a polymer mixture. The polymer mixture is melt-spun by a conventional method to obtain an undrawn yarn. In this case, the extrusion temperature (° C.) is preferably 280 ° C. to 295 ° C., particularly preferably 283 ° C. to 292 ° C. The spinning winding speed (m / min) is preferably 500 m / min to 2000 m / min, and particularly preferably 800 m / min to 1700 m / min.

  There are no particular limitations on the conditions for drawing after spinning by the conventional method. One-stage stretching, multi-stage stretching, roller heater / roller heater stretching, roller heater / plate heater stretching, and the like can be appropriately determined.

  As an example, in the case of untwisting an undrawn yarn obtained by melt spinning by the conventional method, if a roller heater and a plate heater are used, the roller heater is preferably 60 ° C to 90 ° C, particularly 70 ° C to 85 ° C. preferable. The plate heater is preferably from 130 ° C to 170 ° C, particularly preferably from 145 ° C to 160 ° C.

  The draw ratio is preferably set according to the spinning speed (m / min). By determining the spinning speed and the draw ratio in a well-balanced manner, the strength and elongation of the obtained fiber can be adjusted, and a fiber excellent in weaving property can be obtained. For example, when the spinning speed is 1500 m / min, the draw ratio is preferably 2.0 times to 2.4 times, and particularly preferably 2.1 times to 2.3 times.

  The stretching speed (m / min) is preferably 500 m / min to 1000 m / min, and particularly preferably 600 m / min to 900 m / min from the viewpoint of operability. Further, it is preferable to set the spindle rotation speed (rpm) to a value corresponding to the stretching speed. By appropriately determining the number of spindle rotations corresponding to the drawing speed, the number of twists becomes appropriate, and good operability and good shrinkage performance can be obtained. The spindle rotational speed (rpm) is preferably 8 to 12 times the stretching speed (m / min).

  The fineness (dtex) of the fiber of the present invention is not particularly limited, and can be appropriately determined within a range where spinning is possible. For the production of a high-density fabric, the total fineness of warp and weft is preferably 30 dtex to 300 dtex. More preferably, it is 40 dtex-200 dtex, Most preferably, it is 50 dtex-150 dtex. However, when the fineness is too small, the shrinkage performance as a yarn is low, and therefore it is preferable to have a fineness that can sufficiently shrink.

  The single yarn fineness (dtex) and the number of filaments of the fiber of the present invention are not particularly limited, and can be appropriately determined within a range where spinning is possible. Either multifilament or monofilament can be determined as appropriate, but when used as a highly shrinkable woven fabric, a multifilament is preferred because high denseness can be obtained. The single yarn fineness of the multifilament is preferably 1 dtex to 6 dtex, and particularly preferably 2 dtex to 4 dtex.

  The cross-sectional shape of the fiber of the present invention is not particularly limited. From the viewpoint of spinning operability, a round cross section is preferable.

The fiber of the present invention needs to have a breaking strength (cN / dtex) of 4.00 cN / dtex or more. Preferably it is 4.30 cN / dtex or more, and particularly preferably 4.60 cN / dtex or more. High fiber strength makes it possible to weave at high density without causing yarn breakage. When the breaking strength is less than 4.00 cN / dtex, when weaving at a high density, the yarn breaks, and good weaving properties cannot be obtained.

The fiber of the present invention preferably has a breaking elongation (%) of 25% to 55%. More preferably, it is 25% to 45%, particularly preferably 30% to 40%. If it is said breaking elongation, weaving operativity will become favorable.

The fiber of the present invention preferably has a heat shrinkage stress (cN / dtex) of 0.15 cN / dtex or more. More preferably, it is 0.20 cN / dtex or more, and particularly preferably 0.25 cN / dtex or more. If the thermal shrinkage stress is in the above range, a higher density fabric can be obtained by shrinking with a high shrinkage stress when shrinkage processing is performed.

One method for obtaining a high-density fabric using the fiber of the present invention will be introduced below.
The weaving method and weaving structure when weaving the fiber of the present invention are not particularly limited, and can be appropriately determined from the viewpoints of weaving property and design property.

The shrinkage processing method of the woven fabric is not particularly limited and can be appropriately determined. It is preferable to immerse in the hot water while applying a constant tension to the green machine after weaving. At that time, the hot water temperature is 90 ° C. to 100 ° C., the water immersion time is 5 minutes to 30 minutes, and shrinkage is applied while applying a tensile tension of 0.05 cN / dtex to 0.20 cN / dtex in each of the warp direction and the weft direction. It is preferable.

For the high-density fabric after shrinkage processing, the tear strength (N) is preferably 20 N or more in the warp cutting direction and 15 N or more in the weft cutting direction, and has a tear strength in the warp cutting direction. It is particularly preferable that the tear strength in the weft cutting direction is 25N or more and 20N or more. If the tear strength is large, a highly durable high-density fabric can be obtained even after shrinkage processing.

Hereinafter, the present invention will be described in more detail with reference to examples. In addition, this invention is not limited to the Example described below.

A. Measurement of relative viscosity Relative viscosity is measured using an automatic viscosity measuring apparatus (SS-600-L1 type) manufactured by Shibayama Scientific Machinery. The polymer is dissolved at a concentration of 1 g / dl using 95.8% concentrated sulfuric acid as a solvent, and measurement is performed at 25 ° C. in a thermostatic bath.

B. Measurement of breaking strength and breaking elongation Using an AGS-1KNG autograph tensile tester manufactured by Shimadzu Corporation under the conditions of a sample yarn length of 20 cm and a constant speed tensile speed of 20 cm / min according to JIS-L-1013. The value obtained by dividing the maximum value of the load on the load-elongation curve by the fineness is defined as the breaking strength (cN / dtex), and the elongation at that time is defined as the breaking elongation (%).

.
C. Calculation of boiling water shrinkage The method of calculating boiling water shrinkage is as follows. First, the fiber is folded, and a load of 0.2 g is hung on the folded position. After standing at room temperature for 10 minutes and measuring the fiber length,
Soak for 0 minutes. After taking out from boiling water for 10 minutes at room temperature, the fiber length after shrinkage is measured. The boiling water shrinkage Δw can be obtained by the following equation.
Δw = [(L0−L1) / L0] × 100 (%)
L0: Fiber length before shrinkage with a load of 0.2 g L1: Fiber length after shrinkage with a load of 0.2 g applied

D. Measurement of heat shrinkage stress The heat shrinkage stress is measured using a KE-II type shrinkage stress measuring device manufactured by Kanebo Engineering. Measures the thermal contraction force when heated from room temperature at a heating rate of 120 ° C / min by applying an initial load of fineness x 2/30 (cN) to a sample with a thread end tied as a 5 cm long loop. To do. The highest point of the measured thermal contraction force is defined as the peak (cN) of thermal contraction force, and the temperature at that time is defined as the thermal contraction force peak temperature (° C.). A value obtained by dividing the maximum value of the heat shrinkage force by twice the fiber fineness is defined as heat shrinkage stress (cN / dtex).

E. Evaluation of weaving Weaving length when weaving plain weave fabric at a rotation speed of 300 rpm using a Sulzer loom, and we have to stop because we cannot maintain normal weaving due to the occurrence of fluff and yarn breakage Measure. A longer weaving length means better weaving. A weaving length of 500 m or more is regarded as good weaving property, and a weaving length of less than 500 m is regarded as poor weaving property.

F. Cover factor The cover factor is the following formula {total fineness of yarn (dtex)} ^1/2 × {woven fabric density (pieces / 2.54 cm)}
It is expressed by the sum of the cover factors calculated for each warp and weft. A large cover factor means that the area of the yarn occupying the area of the fabric is large, and it can be said that the denseness of the fabric is high.

G. Shrink performance evaluation (cover factor change)
The shrinkage performance of the fabric is evaluated by the change amount of the cover factor. The cover factor change amount is expressed by the following formula CF1-CF0
CF0: Cover factor before contraction processing CF1: Expressed by a cover factor after contraction processing while applying a constant tension of 0.10 cN / dtex in each of the warp direction and the weft direction. When the amount of change in the cover factor is large, it means that the fabric is greatly shrunk by the shrinking process, and it can be said that the shrinkage performance is high. A cover factor change amount of 400 or more is regarded as good shrinkage performance, and a cover factor change of less than 400 is regarded as poor shrinkage performance.

H. Measurement and evaluation of tear strength after shrinkage processing of woven fabric According to A-1 method (single tongue method) described in JIS-L-1096, using a tear strength tester made by Orientec, the short side of the sample side of 5 cm x 25 cm A 10 cm long cut is made in the center at right angles to the sides, and the tensile strength (N) in the warp cutting direction and the tearing strength (N) in the weft cutting direction after shrinkage processing are measured at a pulling speed of 10 cm / min.
If the tear strength in the warp cutting direction is 20 N or more and the tear strength in the weft cutting direction is 15 N or more, the tear strength is good, the tear strength in the warp cutting direction is less than 20 N, or the tear strength in the weft cutting direction is less than 15 N Judged as poor tear strength.

[Example 1]
Nylon 6 polymer chips having a relative viscosity of 3.0 each containing 0.4% by weight of titanium oxide and nylon MXD6 polymer chips having a relative viscosity of 2.7 were vacuum dried.
The moisture content after drying was 130 ppm for nylon 6 polymer and 80 ppm for nylon MXD6 polymer.

  And each polymer was put into one bag so that it might become a weight ratio of 50:50, and it stirred and mixed uniformly. This was melt-spun with a conventional method using a 24-hole spinneret at a spinning temperature of 290 ° C. and a spinning speed of 1500 m / min to obtain an undrawn yarn.

  Thereafter, the undrawn yarn was drawn at a drawing speed of 800 m / min, a spindle rotation speed of 8000 rpm, a roller heater temperature of 85 ° C., a plate heater temperature of 150 ° C., and a draw ratio of 2.2 times to obtain a drawn yarn. When the yarn quality of the drawn yarn was measured, the fineness was 82.9 dtex, the strength was 4.45 cN / dtex, the elongation was 35.3%, and the boiling water shrinkage was 52.7%.

  Then, using the above-mentioned drawn yarn as weft and the warp yarn using homopolyethylene terephthalate fiber having a fineness of 83.4 dtex and 24 filaments, weaving was performed at a rotational speed of 300 rpm to produce a plain weave machine. The raw machine had a warp density of 106 yarns / 2.54 cm, 94 weft yarns / 2.54 cm, and a weaving length of 896 m.

  The green machine was subjected to shrinkage by soaking in 97 ° C. hot water for 20 minutes while applying a constant tension of 0.10 cN / dtex in each of the warp direction and the weft direction. When the fabric density after shrinkage processing was measured, the warp density was 134 / 2.54 cm, and the weft density was 101 / 2.54 cm. When the tear strength after shrinkage processing was measured, the tear strength (N) in the warp cutting direction was 23.2 N, and the tear strength (N) in the weft cutting direction was 17.2 N. Moreover, while having softness, there was moderate firmness and stiffness, and it had a good texture.

<Evaluation of boiling water shrinkage performance due to difference in mixing ratio between nylon 6 and nylon MXD6>
[Examples 2 and 3, Comparative Examples 1 to 4]
Various evaluations were performed on fibers obtained by melt spinning and twisting according to the method described in Example 1 except that the mixing ratio of the nylon 6 polymer and the nylon MXD6 polymer was changed. The results are shown in Table 1.

  In Comparative Examples 1 and 2, since the mixing ratio of the nylon MXD6 polymer was too small, the boiling water shrinkage rate was poor. Accordingly, the shrinkage performance was also low, and a high-density fabric was not obtained. In Comparative Examples 3 and 4, since the mixing ratio of the nylon MXD6 polymer was too large, the shrinkage performance was poor, and a high-density fabric was not obtained. On the other hand, Examples 1 to 3 according to the present invention had a good boiling water shrinkage ratio, high shrinkage performance, and a high-density fabric could be obtained. Moreover, while having softness, there was moderate firmness and stiffness, and it had a good texture.

<Weaving performance evaluation based on fiber strength>
[Examples 4 and 5, Comparative Examples 5 and 6]
Except for changing the fiber strength by changing the relative viscosity, fibers were produced by the method described in Example 1, and weaving performance evaluation and tear strength evaluation after shrinkage processing were performed. The results are shown in Table 2.

  Comparative Examples 5 and 6 had poor weaving properties because of low fiber strength. On the other hand, since Examples 4 and 5 according to the present invention had sufficient strength, good weaving properties could be obtained. The tear strength after shrinkage processing was also good.

  As described above, the highly shrinkable fiber of the present invention has characteristics such as a high boiling water shrinkage ratio and high shrinkage performance, and is suitable for use in a highly shrinkable fabric.

Claims (2)

High shrinkage characterized by fibers composed of nylon MXD6 polymer and nylon 6 polymer, each having a weight ratio of 35:65 to 70:30 and a breaking strength (cN / dtex) of 4.00 cN / dtex or more fiber. The high shrinkage fiber according to claim 1, wherein the weight ratio of the nylon MXD6 polymer to the nylon 6 polymer is 45:55 to 55:45.