JPWO2016104278A1 - Highly shrinkable polyamide fiber and blended yarn and woven / knitted fabric using the same - Google Patents

Abstract

Due to the polyamide fiber having high shrinkage characteristics with high heat shrinkage stress (H) and boiling water shrinkage (B), the mixed yarn using the high shrinkage polyamide fiber at least partially has bulkiness and at least partially A woven or knitted fabric using a polyamide fiber and / or mixed yarn having high shrinkage provides a high shrinkage polyamide fiber that can be formed into a high-density woven or knitted fabric having a feeling of swelling and softness. The highly shrinkable polyamide fiber is a mixture of crystalline polyamide and amorphous polyamide, and the weight ratio of each is crystalline polyamide: amorphous polyamide = 90: 10-50: 50, and the boiling water shrinkage ratio (B) is It is characterized by being 20 to 50% and heat shrinkage stress (H) being 0.15 cN / dtex or more.

Description

  The present invention relates to a polyamide fiber having high shrinkage and a blended yarn and a woven or knitted fabric using the polyamide fiber as a part thereof.

  In recent years, there has been active development of sewing products such as woven fabrics using special fibers not found in conventional fibers. Among them, there are many examples using fibers imparted with high shrinkage, for example, mixed yarn obtained by mixing two kinds of fibers having different heat shrinkability, or boiling water or steam after weaving raw yarn with high heat shrinkability. Numerous developments have been made on fabrics that have been improved in texture and surface properties by heat treatment such as to give them a bulky and bulging feel.

  A typical example of fibers imparted with high shrinkage is high-shrinkage polyester fibers, but polyester fibers have a higher Young's modulus than polyamide fibers, so the texture after heat treatment and shrinkage is hard. There was a problem with comfort as clothing. On the other hand, the polyamide fiber has a low Young's modulus and a soft texture, and has excellent properties such as wear resistance. Therefore, the polyamide fiber is suitably used for clothing applications. A lot of development has been done.

  For example, Patent Document 1 discloses a highly shrinkable polyamide fiber having a boiling water shrinkage ratio of 15% or more. Patent Document 2 discloses a highly shrinkable polyamide fiber having a shrinkage stress of 220 to 400 mg / d. Patent Document 3 discloses a highly shrinkable polyamide fiber having a shrinkage stress of 0.15 cN / dtex or more.

Japanese Unexamined Patent Publication No. 3-64516 Japanese Unexamined Patent Publication No. 2000-73231 Japanese Unexamined Patent Publication No. 2007-100300

  However, the high-shrinkage polyamide fiber disclosed in Patent Document 1 is for blending with other fibers to form a different-shrinkage mixed yarn, but even if the boiling water shrinkage rate (B) is high. When the heat shrinkage stress (H) was low, the fiber was not sufficiently shrunk, and a mixed yarn with bulkiness and a feeling of swelling could not be obtained. In addition, even when heat treatment is applied to a fabric using a high-shrinkage polyamide fiber having a high boiling water shrinkage ratio (B) and a low heat shrinkage stress (H), the heat shrinkage stress (H) is small, so that it does not shrink sufficiently. It was not possible to obtain a high-density fabric with bulkiness and swell.

  The high-shrinkage polyamide fibers disclosed in Patent Documents 2 and 3 have poor spinnability due to poor compatibility between the polymers in the fibers, and a soft texture is mainstream in clothing applications, and due to high-speed yarn production. Since high-efficiency production is the mainstream, there was a problem that it was not possible to cope with single yarn fineness and high-speed spinning. Since the fineness of the single yarn could not be reduced, a high-density fabric with a feeling of swelling and softness could not be obtained. In addition, 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 production cost is increased.

  Accordingly, the present invention solves the above-mentioned problems, and provides a polyamide fiber having high shrinkage having a high shrinkage characteristic such as heat shrinkage stress (H) and boiling water shrinkage (B), and thereby A woven or knitted fabric using a polyamide fiber and / or a mixed yarn having a high shrinkage at least partially has a bulkiness. It is an object to provide a high-density woven or knitted fabric with a soft feeling.

In order to achieve the above object, the highly shrinkable polyamide fiber of the present invention mainly has the following constitution. That is,
(1) A fiber composed of a crystalline polyamide and an amorphous polyamide, wherein the crystalline polyamide and the amorphous polyamide are compatible, and the respective weight ratios are crystalline polyamide / amorphous polyamide = 90 / 10-10. A high-shrinkage polyamide fiber having a 50/50 boiling water shrinkage ratio (B) of 20 to 50% and a heat shrinkage stress (H) of 0.15 cN / dtex or more.
(2) The high shrinkage polyamide fiber according to (1), wherein the total fineness is 5 to 80 dtex and the single yarn fineness is 0.9 to 3.0 dtex.
(3) The highly shrinkable polyamide fiber according to (1) or (2), wherein the rigid amorphous amount is 20 to 45%.
(4) A blended yarn comprising the highly shrinkable polyamide fiber according to any one of (1) to (3) as a part of the blended yarn.
(5) A woven or knitted fabric characterized by using the highly shrinkable polyamide fiber according to any one of (1) to (3) and / or the mixed yarn according to (4) as a part of the woven or knitted fabric.
It is.

  The highly shrinkable polyamide fiber of the present invention has high heat shrinkage stress (H) and boiling water shrinkage (B) and excellent shrinkage characteristics, and is compatible with crystalline polyamide and amorphous polyamide as constituent components. Therefore, single yarn fineness and high speed spinning can be achieved. The high-shrinkage polyamide fiber having high shrinkage property with high shrinkage stress (H) and boiling water shrinkage ratio (B), the mixed yarn using the high-shrinkage polyamide fiber at least partially has bulkiness, and at least A woven or knitted fabric using a polyamide fiber and / or mixed yarn having a high shrinkage in part can be a high-density woven or knitted fabric having a feeling of swelling and softness.

  The highly shrinkable polyamide fiber of the present invention is a fiber composed of crystalline polyamide and amorphous polyamide. Crystalline polyamide is a polyamide that forms crystals and has a melting point, and is a polymer in which a so-called hydrocarbon group is connected to the main chain via an amide bond, and is composed of polycoupleramide, polyhexamethylene adipamide, polyhexamethylene sebaca. Examples thereof include amide, polytetramethylene adipamide, condensation-polymerized polyamide of 1,4-cyclohexanebis (methylamine) and linear aliphatic dicarboxylic acid, and a copolymer or a mixture thereof. However, it is preferable to use a homopolyamide in terms of easy reproduction of a uniform system and stable function expression.

  Crystalline polyamide is a high molecular weight product composed of diamines and dibasic acids. Specific diamines include tetramethylene diamine, hexamethylene diamine, nonamethylene diamine, undecamethylene diamine, dodecamethylene diamine, 2, 2 , 4-trimethylhexamethylenediamine, 2,4,4-trimethylhexamethylenediamine, bis- (4,4′-aminocyclohexyl) methane, metaxylylenediamine and the like. Dibasic acids include glutaric acid, pimelic acid, adipic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecadioic acid, hexadecadioic acid, hexadecenedioic acid, eicosandioic acid, diglycolic acid, 2, Examples include 2,4-trimethyladipic acid, xylylene dicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, and the like. Any crystalline polyamide may be used for the highly shrinkable polyamide fiber of the present invention, but polycapramide and polyhexamethylene adipamide are preferred from the viewpoints of production cost and fiber strength retention.

  The non-crystalline polyamide in the highly shrinkable polyamide fiber of the present invention is a polyamide which does not form crystals and does not have a melting point, such as a polycondensate of isophthalic acid / terephthalic acid / hexamethylenediamine, isophthalic acid / terephthalic acid / Hexamethylenediamine / bis (3-methyl-4-aminocyclohexyl) methane polycondensate, isophthalic acid / 2,2,4-trimethylhexamethylenediamine / 2,2,4-trimethylhexamethylenediamine polycondensate Polycondensate of terephthalic acid / 2,2,4-trimethylhexamethylenediamine / 2,2,4-trimethylhexamethylenediamine, isophthalic acid / terephthalic acid / 2,2,4-trimethylhexamethylenediamine / 2,2 , 4-Trimethylhexamethylenediamine polycondensate, isophthalic acid / Scan polycondensate of (3-methyl-4-aminocyclohexyl) methane / .omega.-laurolactam, there is a polycondensate of terephthalic acid / bis (3-methyl-4-aminocyclohexyl) methane / .omega.-laurolactam. Also included are those in which the benzene ring of the terephthalic acid component and / or isophthalic acid component constituting these polycondensates is substituted with an alkyl group or a halogen atom. Further, two or more of these amorphous polyamides may be used in combination. The amorphous polyamide used for the highly shrinkable polyamide fiber of the present invention may be any, but a polycondensate of isophthalic acid / terephthalic acid / hexamethylenediamine is preferred from the viewpoints of production cost and fiber shrinkage characteristics.

  The weight ratio of crystalline polyamide to amorphous polyamide in the highly shrinkable polyamide fiber of the present invention is crystalline polyamide / amorphous polyamide = 90/10 to 50/50. When the weight ratio of the amorphous polyamide is less than 10% by weight, the shrinkage characteristics of the heat shrinkage stress (H) and the boiling water shrinkage (B) are reduced. However, when the fabric is made, the fabric does not shrink sufficiently even if heat treatment is performed, and the fabric is soft and has a high density. Can't get. Moreover, when the weight ratio of the amorphous polyamide exceeds 50% by weight, the shrinkage characteristics of the heat shrinkage stress (H) and the boiling water shrinkage (B) become too high, and the density of the fabric after the heat treatment becomes too dense, The texture becomes stiff and inferior in swell and softness. Therefore, it is preferable that it is crystalline polyamide / amorphous polyamide = 80 / 20-60 / 40, and it is more preferable that it is 70 / 30-60 / 40 from both sides of manufacturing cost and the shrinkage | contraction characteristic of a fiber.

  The weight ratio here refers to a peak area (A) of a signal (usually around 3 ppm) derived from hydrogen at the α-position of a carboxyl group that forms an amide bond, as measured by proton NMR of a highly shrinkable polyamide fiber, and an aromatic The repeat ratio of the crystalline polyamide and the amorphous polyamide is determined from the peak area (B) of the signal derived from the aromatic hydrocarbon (usually around 7 ppm) (A = the number of repetitions of the crystalline polyamide × 2 + the number of repetitions of the amorphous polyamide) × 2, B = repetition number of amorphous polyamide × 4). The mass number of the repeating unit of polyamide is measured by performing mass spectrometry on the same highly shrinkable polyamide fiber. The weight ratio is calculated from the product of the obtained repetition ratio and the mass number of each polyamide repeating unit.

  For high-shrinkage polyamide fibers, pigments, heat stabilizers, antioxidants, weathering agents, flame retardants, plasticizers, mold release agents, lubricants, foaming agents, antistatic agents, moldability improving agents are added as necessary. A reinforcing agent or the like may be added.

  The highly shrinkable polyamide fiber of the present invention is a compatible system in which crystalline polyamide and amorphous polyamide are compatible with each other. Judgment of compatible system and incompatible system is based on the result of 3000 times TEM observation, when a phase separation structure of a sea island having a dispersed phase having a diameter of 10 nm or more is observed, an incompatible system, a sea island having a dispersed phase having a diameter of 10 nm or more. When no phase separation structure was observed, it was determined as a compatible system. In compatible systems, during fiber production, when the molten polymer is discharged from the spinneret discharge hole, the swell of the yarn (ballast effect) is small and excellent in spinnability. This makes it possible to spin at a high speed. On the other hand, in the incompatible system, since the ballast effect is large and the spinnability is poor and stable spinning cannot be performed, it is impossible to realize single-fine fine yarn and high-speed spinning.

  The high-shrinkage polyamide fiber of the present invention has a boiling water shrinkage (B) of 20 to 50%. By making such a range, when a blended yarn is produced, when heat-treated with boiling water or steam, a yarn length difference is developed due to a shrinkage difference with a fiber having different shrinkage characteristics, and a bulky blended yarn is produced. can get. In addition, when the woven fabric is produced, it is possible to obtain a high-density woven fabric that is sufficiently contracted and swelled and soft when heat-treated with boiling water or steam. When the boiling water shrinkage (B) is less than 20%, when a blended yarn is produced, the yarn length difference is hardly exhibited even when heat treatment is performed, and sufficient bulkiness cannot be obtained. When the fabric is prepared, it is not sufficiently shrunk even if heat treatment is performed, and a high-density fabric with a feeling of swelling and softness cannot be obtained. When the boiling water shrinkage rate (B) exceeds 50%, when a woven fabric is produced, the dimensional change becomes too large when heat treatment is performed, the fabric density becomes too dense, the texture becomes hard, and the bulge is felt. In addition to being inferior in softness, spots are produced in the way the eyes are clogged at the intersection of the fabrics, resulting in shrinkage spots, resulting in inferior fabric quality. The boiling water shrinkage (B) of the highly shrinkable polyamide fiber is preferably 25 to 45%.

  The highly shrinkable polyamide fiber of the present invention has a heat shrinkage stress (H) of 0.15 cN / dtex or more. The heat shrinkage stress (H) mentioned here is a KE-2 type heat shrinkage stress measuring machine manufactured by Kanebo Engineering Co., Ltd. The fiber yarn to be measured is tied into a loop with a circumference of 16 cm, and the yarn fineness (decitex) The initial load of 1/30 g is applied, the temperature is increased at a rate of 100 ° C./min, and the peak value of the obtained thermal stress curve is measured as the maximum thermal stress (cN / dtex). By making the heat shrinkage stress (H) in such a range, when a mixed fiber is produced, it is bulkier by pulling and contracting fibers having different shrinkage characteristics when heat-treated with boiling water or steam. A blended yarn is obtained. In addition, when fabrics are produced, when they are heat-treated with boiling water, steam, etc., fibers with different shrinkage characteristics are pulled tightly and sufficiently shrunk to obtain a dense fabric with a feeling of swelling and softness. it can. If it is less than 0.15 cN / dtex, the heat-shrinkage stress (H) is not sufficient even when heat treatment is performed, and the yarn length difference is difficult to be obtained and sufficient bulkiness can be obtained. In addition, when a woven fabric is produced, even if heat treatment is performed, the woven fabric is not uniformly contracted and shrinkage spots are generated, and a high-density woven fabric having a feeling of swelling and softness cannot be obtained. The heat shrinkage stress (H) of the highly shrinkable polyamide fiber is preferably 0.20 cN / dtex or more, more preferably 0.25 cN / dtex or more. Also, if the heat shrinkage stress becomes too high, when the woven fabric is produced, the shrinking power becomes too high, and the eyes at the intersection of the woven fabric are clogged too much. Since it becomes easy to generate | occur | produce, there exists a tendency for the quality of the obtained textiles to fall. For this reason, the upper limit of the heat shrinkage stress (H) of the highly shrinkable polyamide fiber is preferably 0.50 cN / dtex.

  It is important that the high-shrinkage polyamide of the present invention exhibits shrinkage characteristics when the boiling water shrinkage (B) and the heat shrinkage stress (H) are within the above ranges. That is, it is important to simultaneously satisfy the boiling shrinkage rate (B) representing the dimensional change when heat-treated with boiling water, steam, or the like, and the heat shrinkage stress (H) representing the power (force) to shrink. By making such a range, when a mixed fiber is produced, when it is heat-treated with boiling water, steam or the like, a yarn length difference from a fiber having a different shrinkage characteristic is developed, and a fiber having a different shrinkage characteristic is further pulled. By shrinking, a bulky mixed yarn can be obtained. In addition, when fabrics are produced, when they are heat-treated with boiling water, steam, etc., fibers with different shrinkage characteristics are pulled tightly and sufficiently shrunk to obtain a dense fabric with a feeling of swelling and softness. it can.

  The highly shrinkable polyamide fiber of the present invention preferably has a total fineness of 5 to 80 dtex. In particular, 8 to 50 dtex is more preferable, and 8 to 40 dtex is more preferable from the viewpoint of the strength and lightness of the fabric when used as a sportswear, down jacket, outer and inner base fabric. Moreover, it is preferable that the single yarn fineness of a highly shrinkable polyamide fiber is 0.9-3.0 dtex. In particular, from the viewpoint of the strength and softness of the fabric when used as a sportswear, down jacket, outer and inner base fabric, 0.9 to 2.0 dtex is more preferable, and 0.9 to 1.3 dtex is more preferable. is there. When the single yarn fineness is 3.0 dtex or more, the fabric is hard and stiff, but when the single yarn fineness is within the above range, the mixed yarn that has been heat-treated with boiling water or steam is used. Even in the used sewn product or high-density woven or knitted fabric, good softness can be obtained when worn and comfortable comfort can be realized.

  The high elongation of the highly shrinkable polyamide fiber of the present invention may be a high elongation that is usually used in the case of apparel. From the viewpoint of high-order processing, the elongation is 25 to 50% and the strength is 2.5 cN / dtex. The above is more preferable.

  The fineness unevenness (U%) in the longitudinal direction of the highly shrinkable polyamide fiber of the present invention is preferably 1.2% or less, and 1.0% or less from the viewpoint of the Yokomura quality of the fabric when used as a woven fabric for clothing. More preferred. More preferably, it is 0.8% or less.

The highly shrinkable polyamide fiber of the present invention preferably has a rigid amorphous amount of 20 to 45%. The rigid amorphous amount is a value calculated as follows. Assuming that the content of crystalline polyamide is 100% using the difference between the heat of fusion and the heat of cold crystallization (ΔHm−ΔHc) obtained from normal DSC measurement and the specific heat difference (ΔCp) obtained from temperature-modulated DSC measurement Based on the formulas (1) and (2), the crystallinity (Xc) and the movable amorphous amount (Xma) were obtained. Furthermore, the rigid amorphous amount (Xra) was calculated from the equation (3). The amount of rigid amorphous was calculated from the average value of two measurements of temperature-modulated DSC and DSC.
Xc (%) = (ΔHm−ΔHc) / ΔHm ⁰ × 100 (1)
Xma (%) = ΔCp / ΔCp ⁰ × 100 (2)
Xra (%) = 100− (Xc + Xma) (3)
Here, ΔHm ⁰ and ΔCp ⁰ are the heat of fusion of the crystalline polyamide constituting the highly shrinkable polyamide fiber and the specific heat difference before and after the Tg of the amorphous polyamide, respectively.

  The rigid amorphous amount of the highly shrinkable polyamide fiber of the present invention depends on the restraining force of the crystal part when the fiber structure is formed and the shrinkability of the amorphous part that has mobility when subjected to heat treatment. By setting the rigid amorphous amount in such a range, a desired boiling water shrinkage rate (B) and heat shrinkage stress (H) can be expressed. By setting the amount of rigid amorphous to 20% or more, a desired heat shrinkage stress (H) can be obtained without deteriorating the shrinkage of the amorphous part having mobility by expressing the restraining force of the crystal part. . Moreover, by setting it as 45% or less, the restraint force of a crystal part expresses and the power (force | strength) which an amorphous part shrink | contracts can be hold | maintained, and desired heat contraction stress (H) can be obtained.

A method for producing the highly shrinkable polyamide fiber of the present invention by melt spinning will be described.
The melting part of melt spinning will be described. In melting crystalline polyamide and amorphous polyamide, a pressure melter method or an extruder method can be used. The crystalline polyamide and amorphous polyamide mixed polymer flowing into the spinning pack is discharged from a known spinneret. Further, the melting temperature and the spinning temperature (so-called temperature keeping temperature around the polymer pipe or spinning pack) are preferably a melting point of polyamide + 20 ° C to a melting point + 60 ° C.

  The method of mixing the crystalline polyamide and the amorphous polyamide includes a chip blending method in which the crystalline polyamide chip and the amorphous polyamide chip are mixed together, and a master in which the crystalline polyamide polymer and the amorphous polyamide polymer are previously mixed by melt kneading. Examples thereof include a chip method and a melt kneading method in which a crystalline polyamide polymer and an amorphous polyamide are kneaded with an extruder during melting. In order to form a compatible system, a master chip method and a melt kneading method that can knead more firmly are preferable. In the melt-kneading, it is more preferable to knead firmly with a short-axis or double-axis extruder. More specifically, it is preferable to use one or more sets of kneading elements (kneading discs, paddles) having a strong kneading action and shearing action for the shape and combination of screw elements that can be used in the present invention. It is preferable that Q / N, which is the ratio of the amount Q (kg / h) and the extruder rotation speed N (rpm), is in the range of 0.01 to 0.03. By setting it as this range, it becomes possible to implement | achieve a compatible system by knead | mixing polymers strongly.

  When mixing the crystalline polyamide and the amorphous polyamide, the compatibility system of the crystalline polyamide and the amorphous polyamide can be further stabilized by adding a compatibilizing agent. Specific examples of the compatibilizer include organic silane compounds such as alkoxysilanes having at least one functional group selected from an epoxy group, an amino group, an isocyanate group, a hydroxyl group, a mercapto group, and a ureido group. A functional epoxy compound etc. are mentioned, These can also be used simultaneously 2 or more types. The blending ratio of the compatibilizer is preferably 0.01 to 10 parts by weight, more preferably 0.1 to 5 parts by weight with respect to 100 parts by weight of the crystalline polyamide. When the added amount is 0.01 parts by weight or more, a compatibility improving effect is obtained, and 10 parts by weight or less is preferable because the melt viscosity of the crystalline polyamide is not significantly increased and the fluidity is not impaired. .

About the manufacturing method process of the highly shrinkable polyamide fiber of the present invention, a method in which a spinning-drawing step is continuously performed (direct spinning drawing method), a method in which an undrawn yarn is wound once and then drawn (two-step method), or Although it can be produced by any method such as a method in which the spinning speed is set to 3000 m / min or higher and the drawing process is substantially omitted (high-speed spinning method), direct spinning from the viewpoint of high-efficiency production and production cost. A one-step method of stretching and high speed spinning is preferred.
The production of melt spinning by the direct spinning drawing method will be exemplified.

  The polyamide yarn discharged from the spinneret is cooled, solidified and lubricated in the same manner as in ordinary melt spinning, and then taken up at 1500 to 4000 m / min by the first godet roller. After stretching at 1.0 to 3.0 times between the dead rollers, the film is wound around the package at 3000 m / min or more, preferably 3500 to 4500 m / min.

  At this time, by appropriately designing the ratio of the peripheral speed between the first godet roller and the second godet roller (stretching ratio) and the winding speed (winder speed), the target polyamide yarn is strongly stretched. The degree can be obtained.

  Moreover, you may implement the extending | stretching which made the fluidity | liquidity of the polymer high by giving a heat stretching with the 1st godet roller as a heating roller. By increasing the fluidity, the amount of rigid amorphous is increased, and the heat shrinkage stress (H) is improved by setting the crystalline polyamide and the amorphous polyamide to an appropriate weight ratio.

  Moreover, the heat shrinkage stress (H) of the yarn can be appropriately designed by performing heat setting using the second godet roller as a heating roller. By performing heat setting after stretching, the boiling shrinkage (B) can be reduced by reducing the amount of movable amorphous. The heat setting temperature is preferably 110 to 180 ° C.

  In addition, it is possible to perform entanglement using a known entanglement device in the process up to winding. If necessary, the number of confounding can be increased by giving confounding multiple times. Furthermore, it is also possible to add an oil agent immediately before winding.

  The blended yarn of the present invention uses at least a part of the highly shrinkable polyamide fiber of the present invention. By blending with a highly shrinkable polyamide fiber and a fiber having different shrinkage characteristics, a yarn length difference appears due to a difference in shrinkage characteristics when heat-treated with boiling water, steam or the like, and a bulky blended yarn can be obtained. The fiber having different shrinkage referred to here is a fiber having a different boiling water shrinkage ratio (B) when heat-treated with boiling water or steam. Although not limited to chemical fibers and natural fibers, examples of chemical fibers include polyamide fibers typified by polycapramide and polyhexamethylene adipamide, polyester fibers typified by polyethylene terephthalate, and polypropylene typified by polypropylene. Polyolefin fiber and the like. For clothing use, polyamide fibers and polyester fibers are preferred. Polyamide fibers are more preferred for sportswear, down jacket, outer and inner applications.

  In addition, the difference in boiling water shrinkage between the highly shrinkable polyamide fiber of the present invention and the fiber having different shrinkage characteristics is preferably 10 to 30% from the viewpoint of soft feeling and swelling. More preferably, the difference in boiling water shrinkage is 15 to 30%.

  In addition, the difference in heat shrinkage stress between the highly shrinkable polyamide fiber of the present invention and the fiber having different shrinkage characteristics is preferably 0.10 to 0.40 cN / dtex in terms of soft feeling and bulge feeling. More preferably, the heat shrinkage stress difference is 0.15 to 0.30 cN / dtex.

  The blended yarn of the present invention can be processed by a known method. As the fiber blending method, air fiber blending, synthetic twisting, composite false twisting and the like can be applied. However, air fiber blending is preferable because the fiber blending is easy to control and the manufacturing cost is low. Examples of the air-mixing method include interlace processing, Taslan processing, and processing using a swirling airflow.

  The woven or knitted fabric of the present invention uses at least a part of the high-shrinkage polyamide fiber and / or mixed yarn of the present invention. By weaving and knitting with high-shrinkage polyamide fibers and fibers with different shrinkage characteristics, when heat-treated with boiling water or steam, etc., the high-shrinkage polyamide fibers shrink sufficiently, and the fibers with different shrinkage characteristics are pulled and shrunk. In addition, a high-density woven or knitted fabric with a feeling of swelling and softness can be obtained.

  The woven or knitted fabric of the present invention can be woven or knitted according to a known method. Moreover, the structure of the woven or knitted fabric is not limited. In the case of a woven fabric, the structure may be any of a plain structure, a twill structure, a satin structure, a changed structure thereof, or a mixed structure, but the texture of the woven fabric has a solid texture. In order to achieve this, a flat structure having many restraint points, a ripstop structure combining a flat structure, a stone structure, and a Nanako structure are preferable. In the case of a knitted fabric, the structure may be any of a round knitted fabric, interlocked fabric, warp knitted fabric half, satin, jacquard, or their modified or mixed tissue, depending on the intended use. However, a half-textured fabric such as a single tricot knitted fabric is preferable from the viewpoint that the knitted fabric is thin and stable and has an excellent elongation rate.

  The use of the woven or knitted fabric of the present invention is not limited, but is preferably used for clothing, and more preferably sports such as down jackets, windbreakers, golf wear, and rain wear. Casual wear and ladies' men's clothing. In particular, it can be suitably used for sportswear and down jackets.

Next, the present invention will be described specifically by way of examples.
A. Melting | fusing point The data processing was implemented in Universal Analysis2000 using TA Instrument Q1000 for a differential scanning calorimeter (DSC). The measurement was carried out under a nitrogen flow (50 mL / min) at a temperature range of −50 to 300 ° C., a temperature increase rate of 10 ° C./min, and a sample weight of about 5 g (caloric data is normalized by weight after measurement). The melting point was measured from the melting peak.

B. Relative Viscosity 0.25 g of a sample was dissolved in 25 ml of sulfuric acid having a concentration of 98% by mass so as to be 1 g / 100 ml, and the flow time (T1) at 25 ° C. was measured using an Ostwald viscometer. Subsequently, the flow time (T2) of only sulfuric acid having a concentration of 98% by mass was measured. The ratio of T1 to T2, that is, T1 / T2, was defined as sulfuric acid relative viscosity.

C. Total fineness and single yarn fineness The total fineness and single yarn fineness were measured according to JIS L1013. A fiber sample is wound 200 times with a measuring instrument having a frame circumference of 1.125 m with a tension of 1/30 (g). It was dried at 105 ° C for 60 minutes, transferred to a desiccator, allowed to cool in an environment of 20 ° C and 55RH for 30 minutes, and the weight per 10,000 m was calculated from the value obtained by measuring the weight of the skein. The total fineness of the fiber was calculated as%. The measurement was performed 4 times, and the average value was defined as the total fineness. The value obtained by dividing the total fineness by the number of filaments was defined as the single yarn fineness.

D. Boiling water shrinkage (B)
The fiber sample is made into a loop of 50 cm, an initial load of 1/30 (g) of the fineness is applied to determine the length A, then freed and immersed in boiling water for 30 minutes, then air-dried, and again 1/1 of the fineness. The length B was determined by applying an initial load of 30 (g), and the boiling water shrinkage (B) was calculated by the following equation.
Boiling water shrinkage (B) (%) = [(A−B) / A] × 100

E. Thermal contraction stress (H)
Using a KE-2 type heat shrinkage stress measuring machine manufactured by Kanebo Engineering Co., Ltd., tying the fiber yarn to be measured into a loop with a circumference of 16 cm, applying an initial load of 1/30 g of the fineness of the yarn, and rising from room temperature to 210 ° C Measurement was performed at a temperature rate of 100 ° C./min, and the peak value of the obtained thermal stress curve was defined as the maximum thermal stress.

F. Rigid Amorphous Amount The measurement method for rigid amorphous amount is the difference between the heat of fusion obtained from normal DSC measurement and the heat of cold crystallization (ΔHm-ΔHc), and the specific heat difference obtained from temperature-modulated DSC measurement (ΔCp). The crystallinity (Xc) and the movable amorphous amount (Xma) were determined based on the formulas (1) and (2), assuming that the crystalline polyamide content was 100%. Furthermore, the rigid amorphous amount (Xra) was calculated from the equation (3). The amount of rigid amorphous was calculated from the average value of two measurements of temperature-modulated DSC and DSC.
Xc (%) = (ΔHm−ΔHc) / ΔHm ⁰ × 100 (1)
Xma (%) = ΔCp / ΔCp ⁰ × 100 (2)
Xra (%) = 100− (Xc + Xma) (3)
Here, ΔHm ⁰ and ΔCp ⁰ are the specific heat difference between the heat of fusion of the crystalline polyamide and the Tg of the amorphous polyamide, respectively.

The measurement conditions for normal DSC and temperature modulation DSC were as follows.
(A) Normal DSC
Data processing was carried out with Universal Analysis 2000 using TA Instrument Q1000 in a differential scanning calorimeter (DSC). The measurement was carried out under a nitrogen flow (50 mL / min) at a temperature range of −50 to 300 ° C., a temperature increase rate of 10 ° C./min, and a sample weight of about 5 g (caloric data is normalized by weight after measurement).

(B) Temperature modulation DSC
Data processing was carried out with Universal Analysis 2000 using TA Instrument Q1000 in a differential scanning calorimeter (DSC). Measurement is under nitrogen flow (50 mL / min), temperature range -50 to 270 ° C., temperature rising rate 2 ° C./min, temperature modulation period 60 seconds, temperature modulation amplitude ± 1 ° C., sample weight about 5 g (caloric data after measurement) Measurement was carried out by standardization by weight).

  This method is a method in which heating and cooling are repeated at a constant cycle and amplitude, and the temperature is increased on average, and the entire DSC signal (Total Heat Flow) is measured in a reversible manner such as glass transition. It can be separated into components (Reversing Heat Flow) and irreversible components (Non-Reversing Heat Flow) such as enthalpy relaxation, curing reaction, and desolvation. However, the melting peak of the crystal appears in both the reversible component and the irreversible component.

G. Weight ratio of crystalline polyamide to amorphous polyamide (a) NMR measurement Tetramethylsilane (TMS) was measured as an internal standard substance (0 ppm) using nuclear magnetic resonance spectroscopy ( ¹ H-NMR). Crystals from the peak area (A) of the signal (usually around 3 ppm) derived from the α-position hydrogen of the carboxyl group forming the amide bond and the peak area (B) of the signal derived from the aromatic hydrocarbon (usually around 7 ppm) The repetition ratio of the crystalline polyamide and the amorphous polyamide is determined (A = the number of repetitions of the crystalline polyamide × 2 + the number of repetitions of the amorphous polyamide × 2, B = the number of repetitions of the amorphous polyamide × 4).

(B) Mass spectrometry Matrix-assisted laser desorption / ionization mass spectrometry (MALDI-MS), time-of-flight mass spectrometry (TOF-MS), time-of-flight matrix-assisted laser desorption / ionization mass spectrometry (MALDI-TOF-MS) The mass number of the repeating unit used was determined.

(C) Weight ratio Weight ratio of crystalline polyamide (%) = (A / 2) × (mass number of crystalline polyamide)
Amorphous polyamide weight ratio (%) = (A / 2−B / 4) × (mass number of amorphous polyamide)

H. Compatibility The yarn is exposed to RuO ₄ vapor and coated to clarify the boundary between the yarn and the embedding resin. Thereafter, it is embedded in a resin, a thin section is produced, and stained with a phosphotungstic acid (PTA) aqueous solution for 15 min. The observation object obtained as described above was observed using a transmission electron microscope (H-7100, manufactured by Hitachi, Ltd.) at an applied voltage of 100 kV. The observation magnification was 3000 times and the fiber cross section was observed. In the TEM observation result, when a phase separation structure of a sea island having a dispersed phase having a diameter of 10 nm or more is observed, an incompatible system (×), when a phase separation structure of a sea island having a dispersion phase having a diameter of 10 nm or more is not observed Was determined to be a compatible system (◯).

I. Spinnability The spinnability of the polyamide yarn is determined by judging that it is a poor spinnability (x) when continuous spinning is performed for 8 hours and the yarn breakage occurs three times or more. In the case of less than the number of times, it was determined that the spinnability was good (◯).

J. et al. Fineness unevenness (U%)
The fiber sample was measured four times at 1 / 2In with ZELLweger Uster USTER TESTER III, sample length: 250 m, measurement yarn speed: 50 m / min, measurement range (12.5% HI), and the average value was measured. The U% value was used.

K. Evaluation of blended yarn (a) Production of sheath yarn Polycaprolactam (N6) having a relative viscosity of 2.70 was used and melt-discharged from a spinneret having 60 nozzle discharge holes at a spinning temperature of 275 ° C. After melt-discharging, the yarn is cooled, lubricated, entangled, taken up with a 2560 m / min godet roller, then stretched 1.7 times, heat-set at 155 ° C., and 80 dtex 60 filament at a winding speed of 4000 m / min. Nylon 6 yarn was obtained. The obtained nylon 6 yarn had a fineness of 78.8 dtex, a strength of 4.0 cN / dtex, an elongation of 59%, a boiling water shrinkage of 10%, and a heat shrinkage stress of 0.09 cN / dtex.

(B) Manufacture of blended yarn The nylon 6 yarn obtained in the above (a) and the polyamide yarn obtained in Examples 1 to 6 and Comparative Examples 1 and 5 were entangled using an interlace processing machine. 2.0 kg / cm ² of entanglement treatment was performed to carry out blending processing to obtain a 113 dtex blended yarn.

(C) Tube Knitted Fabric Fabrication A blended yarn sample was adjusted with a tube knitting machine so as to have a stitch of 50, and a tube knitted fabric was fabricated.
The obtained tubular knitted fabric is scoured at 80 ° C. for 20 minutes, then adjusted to pH 4 with Kayanol Yellow N5G 1% owf and acetic acid, dyed at 100 ° C. for 30 minutes, and then at 80 ° C. for 20 minutes. Fix treatment was performed, and finally heat treatment was performed at 170 ° C. for 30 seconds to improve the texture.

(D) Evaluation of tubular knitted fabric The tubular knitted fabric was subjected to the following five stages for each of the bulky feeling (swelling feeling) by the tactile sensation of skilled technicians (5 persons). The average value of the evaluation points of each engineer was rounded off to one decimal place, 5 points were marked as ◎, 4 points as ◯, 3 points as Δ, and 1-2 points as ×.
5 points: Excellent 4 points: Slightly superior 3 points: Neither of them 2 points: Slightly inferior 1 point: Inferior

L. Textile Evaluation (a) Manufacture of warp Polycaprolactam (N6) having a relative viscosity of 2.70 was used and melt discharged from a spinneret having 20 nozzle discharge holes at a spinning temperature of 275 ° C. After melt-discharging, the yarn is cooled, lubricated, entangled, taken up with a 2560 m / min godet roller, then stretched 1.7 times, heat-set at 155 ° C., and 22 dtex 20 filament at a winding speed of 4000 m / min. Nylon 6 yarn was obtained.

(B) Fabrication of woven fabric Nylon 6 yarn obtained in (a) above is used for warp (90 warp density / 2.54 cm), and polyamide yarn obtained in Examples and Comparative Examples is used for weft. The woven fabric was woven (weighing 40 g / cm ² ).

  The resulting fabric is scoured at 80 ° C. for 20 minutes, then adjusted to pH 4 using Kayanol Yellow N5G 1% owf and acetic acid, dyed at 100 ° C. for 30 minutes, and then subjected to Fix treatment at 80 ° C. for 20 minutes. Finally, heat treatment was performed at 170 ° C. for 30 seconds to improve the texture.

(C) Evaluation of woven fabric The woven fabric was subjected to the following five stages for each of a high density feeling, a soft feeling and a bulging feeling by the tactile feeling of skilled technicians (5 persons). The average value of the evaluation points of each engineer was rounded off to one decimal place, 5 points were marked as ◎, 4 points as ◯, 3 points as Δ, and 1-2 points as ×.
5 points: Excellent 4 points: Slightly superior 3 points: Neither of them 2 points: Slightly inferior 1 point: Inferior

[Example 1]
Polycaprolactam (N6) (relative viscosity ηr: 2.62, melting point 222 ° C.) as a crystalline polyamide and isophthalic acid (6I) / terephthalic acid (6T) / hexamethylenediamine polycondensate as an amorphous polyamide A copolymer having an acid / terephthalic acid copolymer ratio of 7/3, a crystalline polyamide / non-crystalline polyamide weight ratio of 90/10, and a biaxial extruder at 275 ° C. and Q / N = 0.17 [Q is discharge rate (kg / h), N is extruder rotation speed (rpm)] and melt-kneaded, and melt discharge using a spinneret having 26 holes and round discharge holes (spinning temperature 275). ° C). The yarn discharged from the spinneret is cooled and solidified, lubricated, entangled, taken up by a non-heated first goded roller (drawing temperature: room temperature), and heated second godet roller (heat set temperature: 150 ° C.) After being stretched 2.4 times, the package was wound at a winding speed (winder speed) of 4000 m / min to obtain a polyamide yarn of 33 dtex 26 filaments.

[Example 2]
Spinning was carried out in the same manner as in Example 1 except that the weight ratio of the crystalline polyamide / non-crystalline polyamide was 80/20 and the first godet roller was drawn at a stretching temperature of 80 ° C. A polyamide yarn was obtained.

[Example 3]
Spinning was carried out in the same manner as in Example 1 except that the weight ratio of crystalline polyamide / non-crystalline polyamide was 70/30 and the first godet roller was drawn at a stretching temperature of 80 ° C. A polyamide yarn was obtained.

[Example 4]
The weight ratio of crystalline polyamide / non-crystalline polyamide is 50/50, the discharge amount is changed, oiling and entanglement are performed, and then the first goded roller is drawn at a stretching temperature of 120 ° C. Spinning was carried out under the same spinning conditions as in Example 1 to obtain a 44 dtex 26 filament raw yarn.

[Example 5]
Polyhexamethylene adipamide (N66) (relative viscosity ηr: 2.82, melting point 263 ° C.) is used as the crystalline polyamide, and isophthalic acid (6I) / terephthalic acid (6T) / hexamethylene is used as the amorphous polyamide. A polycondensate of diamine and a copolymer having an isophthalic acid / terephthalic acid weight ratio of 7/3, a crystalline polyamide / non-crystalline polyamide weight ratio of 70/30, a spinning temperature of 295 ° C., and a discharge rate After changing, refueling and entanglement, stretched 2.8 times between the first goded roller and heated second goded roller (heat set temperature: 150 ° C) at 80 ° C stretching temperature Spinning was carried out under the same spinning conditions as in Example 1 except that the yarn was taken out to obtain a 44 dtex 26 filament raw yarn.

[Example 6]
The same spinning conditions as in Example 5 except that polyhexamethylene sebacimide (N610) (relative viscosity ηr: 2.82, melting point 219 ° C.) was used as the crystalline polyamide, and the spinning temperature was changed to 275 ° C. Spinning was carried out to obtain a polyamide yarn of 44 dtex 26 filaments.

[Example 7]
Polycaprolactam (relative viscosity ηr: 2.62, melting point 222 ° C.) was used as the crystalline polyamide, and isophthalic acid / isophthalic acid (6I) / terephthalic acid (6T) / hexamethylenediamine polycondensate as the amorphous polyamide. A copolymer having a copolymerization ratio of terephthalic acid of 7/3 is used, the weight ratio of crystalline polyamide / amorphous polyamide is 60/40, and a compatibilizing agent (polyfunctional epoxy compound: bisphenol F type epoxy resin) is 2 % By weight, using a twin screw extruder at 275 ° C., Q / N = 0.177 [Q is discharge rate (kg / h), N is the number of revolutions of the extruder (rpm)] A chip was produced. The obtained master chip was melted and discharged (spinning temperature 275 ° C.) using a spinneret having 26 holes and round holes. The yarn discharged from the spinneret was cooled and solidified, and after refueling, a wound undrawn yarn was obtained once at a take-up speed of 800 m / min. Subsequently, the film was stretched at a magnification of 3.6 times, heat-heated (heat set temperature: 170 ° C.), and wound on a package at 600 m / min to obtain a polyamide yarn of 66 dtex 26 filament by a two-step method. .

[Example 8]
Spinning and drawing were carried out under the same spinning conditions as in Example 7 except that the discharge amount was changed, the spinneret having 10 holes and round holes and the draw ratio was changed to 3.8 times. A polyamide yarn was obtained.

[Example 9]
Spinning and drawing were carried out under the same spinning conditions as in Example 7 except that the discharge amount was changed and the draw ratio was changed to 3.8 times to obtain a polyamide yarn of 88 dtex 26 filaments.

[Example 10]
Polycaprolactam (relative viscosity ηr: 2.62) is used as the crystalline polyamide, and terephthalic acid (6T) / 2,2,4-trimethylhexamethylenediamine polycondensate is used as the amorphous polyamide. Spinning and drawing were performed under the same spinning conditions as in Example 7 except that the weight ratio of the amorphous polyamide was 60/40, to obtain a 66 dtex 26 filament polyamide yarn.

[Example 11]
After being drawn by the first godet roller at a stretching temperature of 140 ° C. and stretched 1.3 times between the heated second godet rollers (heat setting temperature: 150 ° C.), the winding speed (winder) Speed) Spinning was carried out under the same spinning conditions as in Example 4 except that the package was wound at 4400 m / min to obtain a 44 dtex 26 filament raw yarn.

[Comparative Example 1]
Spinning was carried out under the same spinning conditions as in Example 1 except that the weight ratio of crystalline polyamide / amorphous polyamide was 95/5 to obtain a polyamide yarn of 33 dtex 26 filaments.

[Comparative Example 2]
As a crystalline polyamide, a copolymer of polycaprolactam and hexamethylene adipamide having a copolymerization ratio of polycaprolactam and hexamethylene adipamide of 85/15 (relative viscosity ηr: 2.69, melting point 198 ° C. ), A polycondensate of isophthalic acid (6I) / terephthalic acid (6T) / hexamethylenediamine as a non-crystalline polyamide and a copolymer having a copolymerization ratio of isophthalic acid / terephthalic acid of 7/3. The weight ratio of polyamide / amorphous polyamide is 70/30 and Q / N = 0.177 at 275 ° C. using a biaxial extruder, Q is the discharge rate (kg / h), and N is the rotation speed of the extruder (rpm )] To prepare a master chip. Except that the obtained master chip was spun at a different discharge rate, spinning and drawing were performed under the same spinning conditions as in Example 7 to obtain a polyamide yarn of 44 dtex 26 filaments.

[Comparative Example 3]
As a crystalline polyamide, a copolymer of polycaprolactam and hexamethylene adipamide having a copolymerization ratio of polycaprolactam and hexamethylene adipamide of 85/15 (relative viscosity ηr: 2.69, melting point: 198 ° C), and a non-crystalline polyamide is a polycondensate of isophthalic acid (6I) / terephthalic acid (6T) / hexamethylenediamine, with a copolymerization ratio of isophthalic acid / terephthalic acid of 7/3. Example 5 except that the weight ratio of crystalline polyamide / non-crystalline polyamide is 70/30, 2% by weight of a compatibilizer (polyfunctional epoxy compound: bisphenol F type epoxy resin) is added, and the discharge amount is changed. Spinning was carried out under similar spinning conditions to obtain a polyamide yarn having 88 dtex 26 filaments.

[Comparative Example 4]
As a crystalline polyamide, a copolymer of polycaprolactam and hexamethylene adipamide having a copolymerization ratio of polycaprolactam and hexamethylene adipamide of 85/15 (relative viscosity ηr: 2.69, melting point: 198 ° C), and a non-crystalline polyamide is a polycondensate of isophthalic acid (6I) / terephthalic acid (6T) / hexamethylenediamine, with a copolymerization ratio of isophthalic acid / terephthalic acid of 7/3. Spinning was carried out under the same spinning conditions as in Example 5 except that the weight ratio of crystalline polyamide / amorphous polyamide was 70/30, and an attempt was made to obtain a polyamide yarn of 44 dtex 26 filaments.

[Comparative Example 5]
Polycaprolactam (relative viscosity ηr: 2.62, melting point: 222 ° C.) is used as the crystalline polyamide, and polycondensate of isophthalic acid (6I) / terephthalic acid (6T) / hexamethylenediamine is used as the amorphous polyamide. Spinning under the same spinning conditions as in Example 4 except that a copolymer having a copolymerization ratio of isophthalic acid / terephthalic acid of 7/3 was used and the weight ratio of crystalline polyamide / amorphous polyamide was 30/70. And a polyamide yarn of 44 dtex 26 filaments was obtained.

[Comparative Example 6]
Polycaprolactam (relative viscosity ηr: 2.62, melting point: 222 ° C.) and nylon MXD6 (manufactured by Mitsubishi Gas Chemical Co., Ltd., relative viscosity ηr: 2.70, melting point: 237 ° C.) as crystalline polyamide, polycaprolactam / nylon Spinning was carried out under the same spinning conditions as in Example 4 except that the MXD6 weight ratio was 50/50, and a 44 dtex 26 filament polyamide yarn was obtained.

  Table 1 shows polymer compositions and spinning conditions of Examples 1 to 11 and Comparative Examples 1 to 6, Table 2 shows raw yarn characteristics and fabric evaluation results, and Table 3 shows raw yarn characteristics and mixed yarn evaluation results.

  As is apparent from the results in Table 2, the woven fabric using the polyamide yarns of Examples 1 to 11 of the present invention as a part (weft) is subjected to a heat treatment process, so that the weft is caused by a difference in shrinkage between the warp and the weft. A high-density woven fabric that exhibits excellent shrinkage due to a synergistic effect of the shrinking action and the action of the wefts pulling the warp and shrinking, and is suitable for apparel and has a soft and soft feeling.

  As is apparent from the results in Table 3, the blended yarn using part of the polyamide yarns of Examples 1 to 6 of the present invention is subjected to a heat treatment process, so that the core is different from the core yarn and the sheath yarn due to the shrinkage difference. An excellent shrinkage was expressed by a synergistic effect of the action of the yarn shrinking and the action of the core yarn pulling the sheath yarn to shrink, and a bulky mixed yarn was obtained.

  In Examples 1 to 4, by appropriately adjusting the weight ratio of the crystalline polyamide and the amorphous polyamide and making them compatible with each other, by setting an appropriate boiling water shrinkage rate (B) and heat shrinkage stress (H), An excellent bulky mixed fiber was obtained. Moreover, it turns out that the high-density fabric with the feeling of swelling and softness suitable for clothes is obtained.

  In Examples 7-9, it turns out that the high-density fabric with the feeling of swelling and softness suitable for clothes is obtained by setting it as the appropriate total fineness and single yarn fineness.

  In addition, the polyamide yarns of Examples 1 to 11 of the present invention can be obtained by appropriately adjusting the weight ratio of the crystalline polyamide and the amorphous polyamide or by using a compatibilizer such as using a compatibilizer. Achieved finer and higher speed yarn production. Further, it can be seen that the obtained polyamide yarn has a small U% and small unevenness in fineness.

  In Comparative Example 1, since the amorphous polyamide weight ratio was small, the heat shrinkage stress (H) and the boiling water shrinkage rate (B) were both low, and the blended yarn was inferior in bulkiness. Moreover, sufficient density was not obtained, and the fabric was inferior in feeling of swelling.

  In Comparative Examples 2 and 3, since there is a large difference in the solidification rate between the crystalline polyamide and the amorphous polyamide, the compatibility between the crystalline polyamide and the amorphous polyamide is poor, the heat shrinkage stress (H) is low, and sufficient The density was not obtained, and the fabric was inferior in swelling. In particular, the fabric of Comparative Example 3 having a large total fineness was inferior in soft feeling. Further, the obtained polyamide yarn had a high U%, and unevenness in fineness was observed.

  In Comparative Example 4, high-speed spinning of a polyamide yarn having a fine single yarn fineness was attempted. However, since the compatibility between crystalline polyamide and amorphous polyamide is poor, the swelling of the yarn when discharged from the spinneret (ballast) (Effect) was large, the spinnability was very poor, stable yarn could not be produced, and polyamide yarn could not be collected.

  In Comparative Example 5, since the amorphous polyamide weight ratio was large, the boiling water shrinkage ratio (B) was high, and the core yarn was too shrunk in the heat treatment step, which was a bulky mixed yarn unsuitable for clothing. . In addition, the weft yarn contracted too much in the heat treatment process, resulting in an excessively dense density, which was inferior to the bulge and softness.

  In Comparative Example 6, since the polyamide yarn was composed of two types of crystalline polyamide, the heat shrinkage stress (H) was low, sufficient density was not obtained, and the fabric was inferior in swell.

Claims (5)

  A fiber composed of a crystalline polyamide and an amorphous polyamide, wherein the crystalline polyamide and the amorphous polyamide are compatible with each other and the weight ratio thereof is crystalline polyamide / amorphous polyamide = 90/10 to 50/50. A high-shrinkage polyamide fiber having a boiling water shrinkage ratio (B) of 20 to 50% and a heat shrinkage stress (H) of 0.15 cN / dtex or more.   The high shrinkage polyamide fiber according to claim 1, wherein the total fineness is 5 to 80 dtex and the single yarn fineness is 0.9 to 3.0 dtex.   The highly shrinkable polyamide fiber according to claim 1 or 2, wherein the rigid amorphous amount is 20 to 45%.   A high-shrinkage polyamide fiber according to any one of claims 1 to 3 is used as a part of the mixed-fiber yarn.   A woven or knitted fabric comprising the highly shrinkable polyamide fiber according to any one of claims 1 to 3 and / or the mixed yarn according to claim 4 as a part of the woven or knitted fabric.