JP2007239139A - Composite false-twisted yarn - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a composite false-twisted yarn having characteristics of "no see-through" in wet state and excellent in windbreaking and heat retaining property, and having a spun like feeling like wool and a soft feeling. <P>SOLUTION: The composite false-twisted yarn comprises a sheath yarn and a core yarn, having characteristics at least increasing percentage of crimp of the sheath yarn by moisture absorbing or water absorbing. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a composite false twisted yarn in which the crimping rate reversibly changes greatly depending on humidity or water absorption.

  It has been well known that natural fibers such as cotton, wool and feathers reversibly change in form and crimp rate due to changes in humidity. Studies have been conducted for a long time to provide a function for synthetic fibers, and proposals for side-by-side type composite fibers of nylon 6 and modified polyethylene terephthalate have already been made in Patent Documents 1 and 2, etc. These known composite fibers have not been put to practical use because the reversible crimp rate change due to humidity change is small.

  Thereafter, Patent Documents 3 and 4 and the like with improved heat treatment conditions have been proposed. Furthermore, the thing which applied the said prior art, such as patent documents 5-8 is proposed. However, in the above-described conventional technology, the change in the crimp rate becomes small after passing through processes such as dyeing and finishing, and the actual situation is that the practical level has not been reached.

  On the other hand, in Patent Document 9, an attempt is made to improve the above-mentioned problem by using a polyamide component and a polyamide component having a high moisture absorption rate, such as nylon 4, in which the polyester component and the polyamide component are joined in a flat shape. However, nylon 4 has poor yarn-making stability, the crimping performance is lowered after heat treatment, and there is a limit in practical use even for such a composite fiber.

  On the other hand, a spun-like swelled fiber has been studied. For example, Patent Document 10 discloses a method of obtaining a frosted fiber by entanglement treatment of two types of yarn spun by spinning blending and then heat treatment. Further, Patent Document 11 uses a method of spinning and blending using two types of polymers having different dyeability, and Patent Document 12 describes blending two types of yarns having different orientations in a drawing process. In addition, a method for obtaining a wrinkle appearance using a difference in light and dark dyeing properties is disclosed. With the blended yarns based on these proposals, it is possible to obtain a spun-like woven or knitted fabric with tone or frosting, but it is impossible to obtain swelling like wool. Furthermore, the above-mentioned mixed yarn does not have a characteristic that crimps change depending on humidity like wool.

  In recent years, demand characteristics have diversified, and “transparent” has become a problem. In other words, when ordinary woven or knitted fabrics made of synthetic fibers or natural fibers are used for swimming wear, sports wear, etc., the fabric becomes easy to be “translucent” by being wet by water or rain, and at that time wind resistance and heat retention There is also a problem that decreases.

Japanese Examined Patent Publication No. 45-28728 Japanese Patent Publication No.46-847 JP 58-46118 A JP 58-46119 A Japanese Patent Laid-Open No. 61-19816 JP 2003-82543 A JP 2003-41444 A JP 2003-41462 A JP-A-3-213518 JP 49-72485 A JP 50-116708 A JP-A-9-316744

  The present invention has been made against the background of the above-described conventional technology, and its purpose is to have a property of “not transparent” even when wet with water, and has excellent windproof properties and heat retaining properties, and also has a splint like wool. An object of the present invention is to provide a composite false twisted yarn that has a feeling of swelling and a soft texture.

  According to the inventor's research, the above object is a composite false twisted yarn composed of a sheath yarn and a core yarn, and at least the sheath yarn is made of a fiber whose crimp rate is increased by moisture absorption or water absorption. It has been found that this can be achieved by a composite false twisted yarn characterized by

  According to the present invention, it is possible to provide a composite false twisted yarn that has a property of “not transparent” even when wet with water and further exhibits windproof properties and heat retaining properties. In other words, the composite false twisted yarn of the present invention is not only spun and swelled, soft and excellent in texture, but also has the effect of new functionality that conventional composite false twist yarn does not have. It is what you play.

  The composite false twisted yarn of the present invention is a composite false twisted yarn composed of a sheath yarn and a core yarn. As a result, it is possible to obtain a soft texture with a span-like swell feeling like wool that cannot be obtained with a false twisted yarn composed of a single fiber.

  It is preferable that there is a difference in average yarn length between the fibers constituting the sheath yarn and the fibers constituting the core yarn. That is, the average yarn length of the fibers constituting the sheath yarn is preferably 5 to 20% longer than the average yarn length of the fibers constituting the core yarn, and more preferably 8 to 15% longer. At that time, in the composite false twisting process, the fibers constituting the sheath yarn are mainly arranged in the sheath part of the composite false twisted yarn, and the fibers constituting the core yarn are mainly arranged in the core part. By doing so, it becomes possible to express a finer fine texture. Moreover, the handleability in the knitting and knitting process is improved, and a softer texture can be obtained. When the yarn length difference between the fibers constituting the sheath yarn and the fibers constituting the core yarn is less than 5%, it is not preferable because the texture of the resulting fabric is hardly spun-like. On the other hand, if the yarn length difference exceeds 20%, the texture of the resulting fabric tends to be fluffy, and yarn breakage frequently occurs during false twisting, which is not preferable.

  In the composite false twisted yarn of the present invention, it is important that at least the sheath yarn is a composite false twisted yarn composed of fibers whose crimp rate increases due to moisture absorption or water absorption. The inventors of the present invention have a composite false-twisted yarn having such a configuration, in which the fabric is not “translucent” even when wet, and the fabric is clogged, and is excellent in windproof and heat retaining properties. I found out. Even when wet, it has a feeling of swelling.

  In the present invention, it is desirable that at least the fiber having an increased crimp rate used for the sheath yarn is a composite fiber having a fiber cross-sectional shape in which a polyester component and a polyamide component are joined.

  The polyamide component is not particularly limited as long as it has an amide bond in the main chain, and examples thereof include nylon 4, nylon 6, nylon 66, nylon 46, nylon 12, and the like. Nylon 6 and nylon 66 are particularly preferable from the viewpoints of performance and versatility. The polyamide component may be copolymerized with other components based on these.

  On the other hand, examples of the polyester component include polyethylene terephthalate, polytrimethylene terephthalate, and polybutylene terephthalate. Among these, polyethylene terephthalate is more preferable from the viewpoint of cost and versatility.

  According to the study by the present inventors, depending on the polymer configuration of the above-mentioned composite fiber, in particular, the polyester component, it is a composite fiber composed of a polyester component and a polyamide component. It was found that processability was obtained. That is, the polyester component is a modified polyester in which 5-sulfoisophthalic acid, which will be described later, is copolymerized, and in this case, the modified polyester preferably has an appropriate intrinsic viscosity. Specifically, the viscosity of the polyester component increases due to the effect of molecular crosslinking with 5-sulfoisophthalic acid, and the component dominates the spinnability and false twist processability, but greatly reduces the intrinsic viscosity of the polyester component. Thus, it is possible to obtain spinnability and false twist workability such as a yarn composed only of the above-mentioned polyamide component, and it is possible to easily obtain a composite false twist yarn having a crimp rate increased by moisture absorption or water absorption according to the present invention. . However, if the intrinsic viscosity of the polyester component is too low, the yarn-forming property is lowered and fluff is likely to occur, which is not preferable in terms of industrial production and quality. For this reason, the intrinsic viscosity is preferably 0.30 to 0.43, and more preferably 0.35 to 0.41.

Moreover, in the above modified polyester, if the copolymerization amount of 5-sodium sulfoisophthalic acid is too small, exfoliation is likely to occur at the bonding interface between the polyamide component and the polyester component, while excellent crimp characteristics are obtained. It is not preferable. Conversely, if the copolymerization amount of 5-sodium sulfoisophthalic acid is too large, crystallization of the polyester is difficult to proceed in the drawing heat treatment and false twisting process, so that the composite false twisted yarn having a high crimp ratio and having a high crimp rate is obtained. When the stretching heat treatment temperature and false twisting temperature are increased in order to promote crystallization, yarn breakage frequently occurs, which is not preferable. For this reason, the copolymerization amount of 5-sodium sulfoisophthalic acid is preferably 2.0 to 4.5 mol%, and more preferably 2.3 to 3.5 mol%.
In addition, both components demonstrated above may contain pigments, such as a titanium oxide and carbon black, a well-known antioxidant, an antistatic agent, a light-resistant agent, etc., respectively.

  As a composite form of the polyamide component and the polyester component in the composite fiber, a form in which both components are joined in a side-by-side manner is preferable from the viewpoint of crimp development. The cross-sectional shape of the composite fiber may be a circular cross-section or a non-circular cross-section. For example, a triangular cross-section or a square cross-section can be adopted as the non-circular cross-section. In addition, a hollow part may exist in the cross section of the said composite fiber.

  The ratio of the polyester component to the polyamide component in the fiber cross section is preferably 30/70 to 70/30, more preferably 60/40 to 40/60, based on the area.

  Furthermore, in order to obtain the characteristics that the crimp rate increases due to a spun-like texture and water absorption / moisture absorption, the breaking elongation of the sheath yarn is preferably 60 to 350%, and preferably 100 to 300%. More favorable results are given. If the elongation at break exceeds 350%, the yarn length difference from the core component tends to exceed 20%, the texture surface tends to be fluffy, and the yarn breakage tends to occur frequently during composite false twisting. On the other hand, if the elongation at break is less than 60%, the yarn length difference is likely to be less than 5%, it becomes difficult to obtain a spun-like texture, and furthermore, the increase in the crimp rate due to moisture absorption is also not preferred.

  In order to produce the above-mentioned composite fiber, for example, as described in JP-A No. 2000-144518, the high-viscosity component side and the low-viscosity side discharge holes are separated and the high-viscosity side discharge linear velocity is reduced. It can be obtained by using a spinneret (with a larger discharge cross-sectional area), allowing molten polyester to pass through the high-viscosity discharge holes, allowing molten polyamide to pass through the low-viscosity discharge holes, joining them, and cooling and solidifying. At this time, it is preferable to wind at a high speed without performing a drawing heat treatment, and a spinning speed of 1000 to 4500 m / min is preferably obtained. When the spinning speed is less than 1000 m / min, the breaking elongation of the resulting composite fiber becomes too high, which is not preferable. On the other hand, when the spinning speed exceeds 4500 m / min, yarn breakage occurs frequently during spinning.

  On the other hand, as the core yarn, for example, a single component of polyester, a composite fiber composed of the same composition as the sheath yarn, a composite fiber composed of polyethylene terephthalate and polytrimethylene terephthalate, or a composite fiber composed of polyethylene terephthalate and polybutylene terephthalate Can be used. However, a polyester single component is preferable from the viewpoint of cost. In this case, polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, or the like can be used as the polyester, but polyethylene terephthalate is more preferable from the viewpoint of cost.

  The total fineness of the composite false twisted yarn of the present invention can be 40 to 200 dtex, and the single yarn fineness of the core yarn and sheath yarn can be 1 to 6 dtex.

  As a method for producing the composite false twisted yarn of the present invention, the core yarn and sheath yarn described above are aligned, preferably air entangled, and composite false twist processing is performed with a known false twist processing machine. It can be manufactured by doing. At that time, a disk type or belt type false twisting device can be used as the false twisting device.

The composite false twisted yarn of the present invention can be used alone, as well as mixed or combined with other fibers.
Of course, the composite false twisted yarn of the present invention and the natural fiber can be further effective, and further combined with urethane or polytrimethylene terephthalate to give further stretchability. It doesn't matter.

  The composite false twisted yarn of the present invention can be used for various applications for clothing. For example, various sportswear, inner materials, uniforms, etc. require comfort such as permeation resistance, wind resistance, and heat retention. Can be used particularly preferably.

  Hereinafter, the present invention will be described more specifically with reference to examples. In addition, each item in an Example was measured with the following method.

(1) Intrinsic viscosity of polyamide and polyester Polyamide was measured at 30 ° C. using m-cresol as a solvent. The polyester was measured at 35 ° C. using orthochlorophenol as a solvent.

(2) Spinnability ○: Continuous spinning is performed for 10 hours, and the yarn breakage is 0 to 1 time, and the spinnability is good.
Δ: Spinning is performed continuously for 10 hours, and the yarn breakage is slightly worse, 2 to 4 times.
X: Spinning is carried out continuously for 10 hours, and the yarn breakage is extremely poor, with 5 or more yarn breaks.

(3) Strength (cN / dtex), elongation (%)
After leaving the fiber sample in a room maintained at a constant temperature and humidity of 25 ° C. and 60% humidity for a whole day and night, the sample length of 100 mm was set on a tensile tester Tensilon manufactured by Shimadzu Corporation, and the speed was 200 mm / min. The strength and elongation at break were measured.

(4) Interfacial exfoliation between polyamide component and polyester component A 1070-fold color cross-sectional photograph of an arbitrary cross section of the composite fiber was taken, and the situation of interfacial exfoliation between the polyamide component and the polyester component in the filament was investigated.
○: There was almost no peeling (0 to 1) at the interface.
Δ: Peeling at the interface was present in 2 to 10 filaments.
X: Peeling at the interface was present in almost all filaments.

(5) Crimp rate DC, crimp rate HC after water immersion, and their difference ΔC
An undrawn yarn used for the sheath yarn was made into a 2700 dtex case and treated in boiling water for 30 minutes under a light load of 6 g (2.2 mg / dtex). The moisture was removed by lightly removing with a filter paper, followed by drying at 100 ° C. for 30 minutes under a load of 6 g (2.2 mg / dtex). Furthermore, this casserole was heat-treated at 160 ° C. for 1 minute under a load of 6 g (2.2 mg / dtex) to obtain a measurement sample.
(A) Crimp rate DC (%)
The measurement material (cassette) subjected to the above treatment was treated under a load of 6 g (2.2 mg / dtex) for 5 minutes, and then this skein was taken out and further 600 g (total 606 g: 2.2 mg / dtex + 220 mg / dtex). ) And left for 1 minute to determine the length L0 of the case. Next, the load of 600 g was removed, and the load was left for 1 minute under a load of 6 g (2.2 mg / dtex), and the length L1 was determined. The crimp rate DC was determined from the following calculation formula.
DC (%) = (L0−L1) / L0 × 100
(B) Crimp rate HC (%) after water immersion
Using the same case after obtaining the crimp rate DC, it was treated in water (room temperature) for 10 hours under a load of 6 g (2.2 mg / dtex). The casserole was wiped off with a filter paper, and a load of 600 g (total 606 g: 2.2 mg / dtex + 220 mg / dtex) was further applied and left for 1 minute to determine the length L2 of the casserole. Next, the load of 600 g was removed, and the product was left for 1 minute under a load of 6 g (2.2 mg / dtex), and the length L3 was determined. The crimp rate DC after water immersion was calculated | required from the following formula.
HC (%) = (L2-L3) / L2 × 100
(C) ΔC (%)
The difference ΔC between the above-described crimp rate DC and the crimp rate HC after water immersion was determined by the following equation.
ΔC (%) = HC (%) − DC (%)

(6) Composite false twist processability: Performs a continuous composite false twist process for 10 hours, and the yarn breakage is 0 to 1 time, and the yarn production is good.
(Triangle | delta): A continuous composite false twist process is performed for 10 hours, and a thread breakage is 2-4 times.
X: A continuous composite false twisting process is performed for 10 hours, and the yarn breakage is extremely poor with 5 or more yarn breaks.

(7) Difference in the length of the fibers constituting the core yarn and sheath yarn A load of 0.176 cN / dtex (0.2 g / de) is applied to one end of a 50 cm composite false twisted yarn, and it is suspended vertically. Were marked at intervals of 5 cm. The load was removed, and the marking portion was cut accurately to prepare 10 samples. Ten fibers (filaments) in the sheath part and fibers (filaments) in the core part are each taken out from the sample, and each single yarn is multiplied by a weight of 0.03 cN / dtex (1/30 g / de) to obtain a vertical Hang it on and measure the length of each. The above-mentioned measurement was performed on 10 samples, and the average value of each of the samples was La (sheath portion yarn length) and Lb (core portion yarn length), and the yarn length difference was calculated by the following formula.
Yarn length difference = (La−Lb) / La × 100%

(8) Change in shape of cylinder knitting A composite false twisted yarn was knitted in a cylinder, boiled with a cationic dye, set in a dry heat at 160 ° C. for 1 minute after washing with water, and used as a measurement sample. Water is dropped onto this tubular knitting, and the situation of the water dripping part and its surroundings is investigated with a side photograph (magnification 200) of the tubular knitting. Was judged.
(A) Stitch change ○: The stitch is remarkably shrunk by water dripping (the voids are reduced).
X: The stitch is rather elongated by water dripping (the voids are widened).
(B) Opaque feeling ○: The sense of transparency is lowered and the opacity is increased by dripping water.
X: The sense of transparency is increased by dripping water, and the transparency is increased (the opacity is decreased).

(9) Texture The composite false twisted yarn was knitted in a cylinder, boiled with a cationic dye, set in a dry heat at 160 ° C. for 1 minute after washing with water, used as a measurement sample, and evaluated by its tactile sensation.
○: The texture is span-like, swelled and soft.
X: The texture is not spanlike.

[Example 1]
Nylon 6 having an intrinsic viscosity [η] of 1.3 and modified polyethylene terephthalate copolymerized with 3.0 mol% of 5-sodium sulfoisophthalic acid having an intrinsic viscosity [η] of 0.39 are each 270 ° C. Melted at 290 ° C., formed a side-by-side type composite yarn at a discharge rate of 8.3 g / min using a composite spinneret described in JP-A-2000-144518, and applied cooling solidification / oil agent After that, the yarn was wound at a speed of 1000 m / min to obtain an undrawn yarn of 167 dtex 24 fil.

Next, a polyethylene terephthalate having an intrinsic viscosity [η] of 0.64 and containing 0.3% by weight of titanium oxide is melted at 300 ° C., and a discharge amount using a spinneret having 12 discharge holes having a hole diameter of 0.30Φ is used. After extruding at 40.3 g / min and cooling and solidifying, an undrawn yarn having a winding speed of 3300 m / min and winding of 122 dtex 24 fil was obtained. The obtained undrawn yarn had a strength of 2.5 cN / dtex and an elongation of 135%.
The above-mentioned two types of undrawn yarns are gathered, entangled with air (interlace (IL) treatment), composite false twisted using a friction type false twisting machine under the following conditions, and combined with 186 dtex 36 fil. A twisted yarn was obtained. The results are shown in Table 1.

(False twisting conditions)
・ Machining speed 300m / min ・ Machining magnification 1.55
・ Processing temperature 140 ℃ (non-contact heater (effective length 90cm) used)
・ D / Y 1.8
-Entanglement treatment OF: 0.5%, IL pressure: 2.0 kg / cm ²

[Examples 2-6, Comparative Examples 1-3]
A composite false twisted yarn was obtained in the same manner as in Example 1 except that the composite false twist processing temperature (heater) temperature was changed as shown in Table 1. The results are shown in Table 1.

[Examples 7 to 12, Comparative Examples 4 to 6]
A composite false twisted yarn was obtained in the same manner as in Example 1 except that the spinning speed was changed as shown in Table 1. The results are shown in Table 1.

[Examples 13 to 14, Comparative Examples 7 to 8]
A composite false twisted yarn was obtained in the same manner as in Example 1 except that the copolymerization amount of 5-sulfoisofluric acid as the modified polyester component was changed as shown in Table 1. The results are shown in Table 1.

[Examples 15 to 16, Comparative Examples 9 to 10]
A composite false twisted yarn was obtained in the same manner as in Example 1 except that the intrinsic viscosity [η] of the modified polyester component was changed as shown in Table 1. The results are shown in Table 1.

  In Examples 1 to 16, in the composite false twisted yarn, it was confirmed that the crimp rate of the sheath yarn increased due to moisture absorption or water absorption as in the case of the undrawn yarn.

  According to the present invention, it is possible to provide a composite false twisted yarn that has a property of “not transparent” even when wet with water and further exhibits windproof properties and heat retaining properties. In other words, the composite false twisted yarn of the present invention is not only spun-like and swelled, soft and excellent in texture, but also has a new function that conventional composite false twisted yarn does not have. And its industrial value is extremely high.

Claims (4)

  A composite false twisted yarn composed of a sheath yarn and a core yarn, wherein at least the sheath yarn is made of a fiber whose crimp rate is increased by moisture absorption or water absorption.   The composite false twisted yarn according to claim 1, wherein the average yarn length of the fibers constituting the sheath yarn is 5 to 20% longer than the average yarn length of the fibers constituting the core yarn.   The fibers according to claim 1 and claim 2, wherein the fiber whose crimp rate increases by moisture absorption or water absorption is a composite fiber having a fiber cross-sectional shape in which a polyester component and a polyamide component are joined. Composite false twisted yarn.   The polyester component is a modified polyester in which 5-sodium sulfoisophthalic acid is copolymerized in an amount of 2.0 to 4.5 mol% based on the acid component, and its intrinsic viscosity (IV) is 0.30 to 0.43. The composite false twisted yarn according to claim 3.