JP2008133565A - Crimped yarn, and fiber structural product and plaster using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a low-modulus crimped yarn good in elastic recovery, excellent in product grade, satisfying various properties including medicament carrying capacity, chemical resistance and hydrolysis resistance, and having practical durability as well, and to provide a fiber structural product and a plaster comprising the crimped yarn. <P>SOLUTION: The crimped yarn comprises sheath/core-type conjugate fibers with the sheath component consisting of polytrimethylene terephthalate and the core component consisting of a polyester except polytrimethylene terephthalate, wherein the weight fraction of the core component is 20-40 wt.% and the modified cross-section degree of the single filament is 1.5 or less. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a crimped yarn composed of a core-sheath composite fiber in which the sheath component contains polytrimethylene terephthalate (hereinafter sometimes abbreviated as PTT).

  Patches represented by plaster agents, haptic agents, ship agents, and the like are required to have low resistance to bending and stretching and be difficult to peel off when applied to, for example, bending and stretching sites such as elbows and knees. In addition, it is required to follow the movement of the skin even in repeated bending and stretching movements and not to wrinkle. That is, the base material for the patch is required to have low modulus (characteristic that elongates with low stress) and elastic recovery (characteristic that elongates when the stress is removed).

  In order to give the patch such characteristics, synthetic fibers such as polyethylene terephthalate (hereinafter sometimes abbreviated as PET) fibers, or fabrics such as cotton (woven fabric, knitted fabric, non-woven fabric) are used for the patch. As a base fabric (hereinafter sometimes simply referred to as a patch base fabric), a patch in which a drug is carried on the base fabric is used.

  The patch base fabric is required to have low modulus and elastic recovery, and can be applied directly to the skin and touched by the human eye, so the product quality (no roughness, soft touch, low irritation, etc. It is also required that the surface of the base fabric is excellent in tactile sensation and has a good product appearance. And drug-carrying property (the drug is carried and the drug is not smeared on the opposite side of the drug application surface), chemical resistance (the physical properties of the base fabric are not degraded by the drug), hydrolysis resistance (long-term product) Various properties such as storage and heat sterilization treatment are required to prevent the strength of the base fabric from decreasing. Further, of course, practical durability that can maintain the above characteristics is also required by the stretching force and frictional force applied to the movement.

  Conventionally, a knitted fabric made of a PET crimped yarn has been used as a patch base fabric in that the required characteristics as described above can be satisfied.

  However, the knitted fabric made of PET crimped yarn does not always have sufficient followability to the skin movement, and in particular, when affixed to a flexion / extension site, it is applied with the flexion / extension site (elbow, knee) stretched. When attached, the skin may be pulled to feel resistance when bent deeply, and there are also problems such as peeling of the patch when bent repeatedly. This is because PET has a high modulus and has almost no elastic recovery. By increasing the crimp rate of the crimped yarn and adjusting the knitting density low, voids are formed between single fibers and between multifilaments. This is because these properties are expressed by lowering the restraint between the fibers.

  In recent years, there has been a strong demand for comfort when worn, and although improvement in the feel of the base fabric has been sought as well as lower modulus and elasticity recovery of the base fabric, increasing the count to reduce the fineness of the single fiber There is a tendency for crimps to be easily set due to external forces received during the manufacturing process and use of products, and crimped yarns made of PET are naturally limited.

  Then, the base fabric for patch which consists of a knitted fabric containing the crimped yarn of polytrimethylene terephthalate is proposed (refer patent document 1). Certainly, according to the technique of Patent Document 1, a patch fabric having a low modulus and excellent elastic recovery can be obtained by using a crimped yarn made of polytrimethylene terephthalate, which is a polymer excellent in elastic recovery. Can do. However, as an impediment factor because polytrimethylene terephthalate polymer has elastic recoverability, it is possible to delay the recovery after winding the fiber in the spinning, drawing and false twisting processes, thereby avoiding the adverse effects caused by this. This is a new issue. This adverse effect will be described below. Polytrimethylene terephthalate has a crystal structure in which the methylene chain portion is bent and is said to have an extremely low crystal elastic modulus, and the crystal structure itself is easily stretched by the processing tension during spinning, stretching, and false twisting. . That is, it is considered that the delayed recovery property occurs when the crystal structure of PTT is elongated by the processing tension and this is elastically recovered with a time delay. In particular, since high tension is applied in the spinning and drawing processes, the wound yarn is elastically recovered and tightened after the cheese package is formed. In severe cases, the cheese package cannot be pulled out from the winder, In some cases, it must be cut. Although certain improvements can be achieved by reducing the spinning speed, the draw ratio, and increasing the relaxation rate of winding, it has been difficult to completely suppress the tightening phenomenon due to delayed recovery. Moreover, in order to increase the elastic recovery of the polytrimethylene terephthalate fiber, it is preferable to orient molecular chains (amorphous chain and crystal chain) in the fiber axis direction. In some cases, recoverability could not be maximized.

  Further, as a result of the tightening phenomenon, the inner layer fibers are pressed against the outer layer fibers, so that the thickness of the single fiber, the internal structure, or the fibers having spots in the longitudinal direction is also a problem. These are unfavorable because they cause dyeing spots on the base fabric and cause a rough feeling on the surface of the base fabric. In particular, as the patch base fabric is often used as described above, the base fabric with a low knitting density is used. However, it will be embossed as a product defect. Furthermore, the biggest problem is that the spots generated in the fibers due to the winding tightening are gradually deteriorated from the outer layer to the inner layer of the winding package. This causes a stepwise dyeing difference in the patch base fabric, which is fatal when considering industrial production. Polytrimethylene terephthalate has low modulus and elastic recovery that are not found in conventional PET, so it is promising as a patch base fabric, but there are problems in terms of product quality and passability in the manufacturing process. It was.

  On the other hand, polylactic acid is coated with aromatic polyester on the surface of polylactic acid fiber to improve wear resistance and heat resistance, impart practical hydrolysis resistance, and at the same time develop biodegradability in compost treatment A crimped yarn has been proposed (Patent Document 2). Example 4 of Patent Document 2 discloses a short fiber subjected to mechanical crimping, in which the sheath component is made of polytrimethylene terephthalate and contains 50% by weight of polylactic acid as the core component. However, the short fibers disclosed in Example 4 have a certain improvement effect in abrasion resistance, heat resistance and hydrolysis resistance as compared with polylactic acid fibers, but the crimp rate is insufficient, and polytrimethylene The excellent elastic recovery property of the terephthalate polymer was not exhibited. Further, in Patent Document 2, spiral crimps can be expressed by arranging the core component in an eccentric manner, and the degree of occurrence of spiral crimps, wear resistance, and compost treatment can be determined by the eccentricity in the cross section of the single fiber. It is also described that the hydrolyzability in can be controlled. However, the short fibers of Example 4 are arranged eccentrically in spite of being produced with the aim of arranging the core component and the sheath component concentrically using a concentric core-sheath type composite melt spinning apparatus, It has also been suggested that such an unintended core component is likely to be unevenly distributed.

  Patent Document 3 discloses a crimped yarn in which an aromatic polyester having a melting point of 200 ° C. or higher is disposed on the surface of an aliphatic polyester fiber, and the thickness of the aromatic polyester is within a specific range. By this technology, it is excellent in abrasion resistance, heat resistance, and hydrolysis resistance, and a practical level of aliphatic polyester crimped yarn can be obtained. By using polytrimethylene terephthalate as the sheath component, high bulkiness can be expressed by false twisting, and the elastic recovery and flexibility that are the characteristics of the polytrimethylene terephthalate also allow for repeated bending at the composite interface. It is difficult to store strain energy, it is difficult to peel off at the core-sheath interface, and a crimped yarn having high practical durability can be obtained.

However, as described above, the patch base fabric has excellent comfort (low modulus, elastic recovery) at the same time as wearing, as well as various properties such as product quality, drug support, chemical resistance, and hydrolysis resistance. The crimped yarn disclosed in Patent Document 3 was insufficient because it was satisfactory and required to have excellent balance in practical durability.
JP 2002-20272 A (Claims) JP-A-2004-353161 (Claims and Examples) Japanese Patent Laying-Open No. 2005-232627 (Claims)

  The present invention is excellent in low modulus and elastic recovery, at the same time excellent in product quality, satisfying various properties such as drug loading, chemical resistance and hydrolysis resistance, and also has practical durability. It is an object of the present invention to provide a crimped yarn, a fiber structure comprising the crimped yarn, and a patch.

  As a result of further trials on the short fibers of Example 4 of Patent Document 2, the present inventors have found that in addition to the crimping rate, the elastic recoverability is insufficient, and the excellent elastic recoverability of polytrimethylene terephthalate cannot be exhibited. I understood that. And since the form of the fiber is a short fiber, polylactic acid is exposed at the cut surface, and even if a patch base fabric is produced by making a knitted fabric as a spun yarn, making the short fiber a non-woven fabric, In the production process such as the dyeing process and the heat sterilization treatment process, polylactic acid was remarkably hydrolyzed, and the strength decrease before and after the dyeing was so great that it was not practical. As the hydrolysis of the core component proceeds, the interfacial adhesion between the core component and the sheath component decreases, and the phenomenon of interfacial peeling due to external force and white blurring is confirmed. The use was limited to non-dyed applications.

  Further, Patent Document 2 also exemplifies long fiber processed yarn subjected to false twisting and the like. However, when false twisting is applied to the fiber of Patent Document 2, compressive force applied to the single fiber in the false twisting process. As a result, the cross section of the single fiber was deformed, and the crimped yarn had a high degree of irregularity. It was found that the fiber structure thus obtained has streaky spots after dyeing, and has a rough surface due to reduced surface smoothness, resulting in poor quality fiber structures.

  Therefore, as a result of intensive studies on the crimped yarn that is suitably used even in a low-density fiber structure such as a patch base fabric, the present inventors have determined that the sheath component is composed of polytrimethylene terephthalate, and the core component has a specific amount. Polytrimethylene terephthalate is a core-sheath composite fiber containing polyester other than polytrimethylene terephthalate. It was also found to be excellent in practical durability. Further, by selecting the polytrimethylene terephthalate constituting the sheath component, the polyester other than the polytrimethylene terephthalate constituting the core component, the weight fraction of the core component, and the conditions of spinning, stretching, false twisting, The present invention has been completed by succeeding in suppressing the deformation of the cross section during false twisting, which was a problem with crimped yarns composed of core / sheath composite fibers.

  That is, in the present invention, the sheath component comprises polytrimethylene terephthalate, the core component is composed of a core-sheath composite fiber comprising polyester other than polytrimethylene terephthalate, and the core component has a weight fraction of 20 to 40 wt. %, And the degree of irregularity in the cross section of the single fiber is 1.5 or less, and can be achieved by a crimped yarn, a fiber structure comprising the crimped yarn, and a patch.

  According to the present invention, the uniformity of the fiber, which has been a problem of the conventional polytrimethylene terephthalate fiber, can be remarkably improved, and the low modulus property, elastic recovery property, and heat and heat aging resistance of the polytrimethylene terephthalate are improved. A crimped yarn that does not deteriorate the characteristics of polytrimethylene terephthalate such as property can be obtained. Furthermore, since it is a crimped yarn with a small degree of deformity that suppresses deformation of the cross section in the false twisting process, it is possible to obtain a high-quality fiber structure that is excellent in leveling and has no surface roughness.

  Further, the crimped yarn of the present invention has a very low modulus because it is a crimped yarn having high bulkiness and excellent single fiber uniformity even when it is a fine denier crimped yarn having a small single fiber fineness. Therefore, it is possible to provide a knitted fabric having high elastic recovery, good product appearance, and good touch with peach touch.

  The fiber structure of the present invention, when used as a base fabric for a patch, is not only excellent in comfort, adhesion and skin followability during wearing, but also in product quality (no roughness, soft touch and low irritation. It has excellent touch on the surface of the base fabric and a good appearance of the product, etc., and has excellent durability against external forces, drug loading, chemical resistance, and moisture heat aging resistance. For this reason, it is applied to humans or animals for a certain period of time, such as haptics for anti-inflammatory analgesics, plasters, syrups, hot compresses, cold compresses, and tapes used for sports and body protection. It is suitably used as a base material for patches to be discarded.

  The crimped yarn and the fiber structure of the present invention are excellent in low modulus and elastic recovery, product quality, durability against external force, chemical resistance, and moist heat aging resistance. It can use suitably also for the use of. For example, clothing (outdoor wear, golf wear, athletic wear, ski wear, snowboard wear and sportswear such as pants, casual wear such as blousons, coats, winter clothes and rainwear outerwear for women and men, uniforms, etc. ), Bedding materials (clothes, mattresses, skin comforters, kotatsu comforters, cushions, baby comforters, blankets, etc., pillows, skins and covers such as cushions, mattresses and bed pads, hospital, medical, hotel use And baby sheets, and also a sleeping bag, a cradle, a stroller cover, etc., which can be preferably used. And since it is excellent in durability against external force and heat and heat aging resistance, it can be suitably used as interior materials for automobiles, trains and airplanes (for skins such as seats, ceilings, pillars and door trims, BCF car mats). it can.

  In the crimped yarn of the present invention, the sheath component of the single fiber needs to be made of polytrimethylene terephthalate (PTT).

  PTT is a polyester containing a repeating unit composed of a 1,3-trimethylene glycol component and a terephthalic acid component (hereinafter sometimes referred to as a trimethylene terephthalate unit), and the glycol component has 3 carbon atoms. By having a methylene chain, the crystal structure itself expands and contracts with respect to elongation deformation as described above. Therefore, compared with PET and polybutylene terephthalate (PBT), it is preferable because of its extremely low modulus and high elastic recovery. In addition, it has been found by the present inventors that the durability (strength retention) due to PET contrast, wet heat treatment, alkali treatment, etc. is 2 to 4 times, and as a constituent of the crimped yarn of the present invention Is optimal.

  As the PTT, a copolymerized PTT containing other repeating units in addition to the trimethylene terephthalate unit may be adopted. However, in order to take advantage of the characteristics of the PTT, a PTT having a trimethylene terephthalate unit of 90 mol% or more is used. It is preferable to adopt. More preferably, it is 92 mol% or more, More preferably, it is 95 mol% or more.

  In the case of a copolymerized PTT polymer, examples of the copolymer component include, for example, isophthalic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, and 1,5-naphthalenedicarboxylic acid as dicarboxylic acid components. Aromatic dicarboxylic acid components such as acid, 4,4 ′ diphenyl dicarboxylic acid, 4,4 ′ diphenyl ether dicarboxylic acid, 4,4 ′ diphenyl sulfone dicarboxylic acid, 5-sodium sulfoisophthalic acid, succinic acid, adipic acid, suberic acid In addition, aliphatic dicarboxylic acid components such as sebacic acid, dodecanedioic acid, dimer acid, and eicosandioic acid can be used. These acid components can be used singly or in combination of two or more.

  Examples of the glycol component include ethylene glycol, 1,2-trimethylene glycol, neopentyl glycol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, , 2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, diethylene glycol, triethylene glycol, polyalkylene glycol, 2,2′bis (4′-β-hydroxyethoxyphenyl) propane, etc. Can be used. These glycol components may be used alone or in combination of two or more.

  In addition, it is defined that 80 weight% or more of a sheath component is comprised with PTT that a sheath component consists of PTT, Preferably it is 85 weight% or more, More preferably, it is 90 weight% or more. Further, depending on the purpose, other polymers, particles, flame retardants, antistatic agents, antioxidants, ultraviolet absorbers and the like may be contained.

  Further, as a result of the study by the present inventors, if a cyclic dimer (hereinafter referred to as a cyclic dimer) in which two trimethylene terephthalates are connected in a cyclic manner is present in the crimped yarn, It was found that the sex was significantly worsened. This is presumed to be because the cyclic dimer becomes trimethylene terephthalate monomer by hydrolysis and promotes hydrolysis by the catalytic action of the monomer. Therefore, the content of the cyclic dimer in the crimped yarn is preferably 3% by weight or less, more preferably 2.5% by weight, and further preferably 2% by weight or less.

  The PTT constituting the sheath component of the present invention preferably has an intrinsic viscosity of 0.8 to 2 dl / g, which is an index of molecular weight. The higher the molecular weight of PTT, the higher the molecular orientation of PTT in the production process, and the better the elastic recovery of the crimped yarn and the fastness of elastic recovery. However, if the molecular weight is too high, the molecular weight will suddenly drop when melted, resulting in viscosity spots in the polymer, making it difficult to stabilize the melt flow in the spin pack and spinneret, and in the cross section of the core-sheath composite yarn. There may be a problem in the manufacturing process in which components are unevenly distributed. Therefore, the intrinsic viscosity is more preferably 1 to 1.8 dl / g, and further preferably 1.2 to 1.6 dl / g.

  The crimped yarn of the present invention is required to have a core component made of polyester other than polytrimethylene terephthalate. As a result of diligent investigations to make the best use of the characteristics of the PTT polymer and to suppress the tightening that is a demerit of PTT and the accompanying thread spots, the present inventors have surprisingly found that the core component is other than polytrimethylene terephthalate. For the first time, it is possible to suppress delayed recovery, which was a problem with conventional crimped yarns containing PTT, and avoid tightening in the manufacturing process. I found what I could do. Moreover, even when it is a fiber structure, it has been found that it becomes a crimped yarn that is extremely excellent in leveling and excellent in product quality. On the other hand, when the ratio of the core component is 40% by weight or less, the crimped yarn is optimal when it is made into a fiber structure without impairing the characteristics of PTT such as low modulus, high elastic recovery, and hydrolysis resistance. I found out that

  As the polyester other than polytrimethylene terephthalate used for the core component, a conventionally known polyester can be adopted as long as it is a polymer containing a repeating unit composed of a glycol component and a dicarboxylic acid component.

  Polyesters other than polytrimethylene terephthalate are, for example, polyesters composed of a dicarboxylic acid component and a glycol component. As the dicarboxylic acid component, terephthalic acid, isophthalic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid, 1,4-naphthalene. Aromatic dicarboxylic acid components such as dicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 4,4′diphenyldicarboxylic acid, 4,4′diphenyletherdicarboxylic acid, 4,4′diphenylsulfonedicarboxylic acid, 5-sodiumsulfoisophthalic acid, , Succinic acid, adipic acid, suberic acid, sebacic acid, dodecanedioic acid, dimer acid, eicosandioic acid, and other aliphatic dicarboxylic acid components can be used. You may use together.

  Examples of the glycol component include ethylene glycol, 1,3-trimethylene glycol, 1,2-trimethylene glycol, neopentyl glycol, 1,3-butanediol, 1,4-butanediol, and 1,5-pentanediol. 1,6-hexanediol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, diethylene glycol, triethylene glycol, polyalkylene glycol, 2,2′bis (4 ′ -Β-hydroxyethoxyphenyl) propane or the like can be used. These glycol components may be used alone or in combination of two or more.

  Polyesters other than polytrimethylene terephthalate are intended to suppress the delayed recovery of PTT, and need not be a polymer composed of PTT. Since polyester having higher crystallinity and higher dimensional stability tends to suppress delayed recovery, 90 mol% or more of the polyester other than polytrimethylene terephthalate as a core component contains one type of dicarboxylic acid component and one type of polyester. It is preferably composed of a repeating unit composed of a glycol component, more preferably 92 mol% or more, and still more preferably 95 mol% or more.

  The polyester as the core component of the present invention is preferably polyethylene terephthalate (PET) or polylactic acid. It is preferable to arrange PET or polylactic acid as a core component because the uniformity and bulkiness of the crimped yarn obtained in particular are enhanced. The reason why PET or polylactic acid is particularly preferable as the polymer of the core component is not clear, but is presumed to be due to the following reason.

  The sheath component PTT is a polymer having low heat resistance during melt storage. For this reason, an appropriate melting temperature region is narrow and is 245 to 280 ° C. Therefore, when performing composite spinning, at least a spin pack, a base, such as a spinneret, has a flow path for flowing two component polymers at the same temperature, so that the core component exhibits good fluidity in the above temperature range, It is also preferable that the heat resistance during melt storage is high. When PET or polylactic acid is disposed as the core component, the flow temperature of the two-component polymer such as a spin pack and a base, which flows at the same temperature, is easily set in the above range, which makes it easy to suppress thermal decomposition of the PTT polymer, which is preferable. .

  In addition, PET and polylactic acid have a higher glass transition temperature (Tg) than PTT, which affects the solidification point of the spinning line in melt spinning (glass transition temperature, PTT: 48 ° C., PET: 70 ° C., PLA: 58 ° C.), PET, or polylactic acid is preferably used as a core component, since thinning proceeds at the upstream portion of the spinning line where the yarn temperature is high, and it becomes easy to complete the thinning upstream. Due to this effect, the yarn is cooled quickly, and the fluctuation of the solidification point tends to be small. Therefore, in the stage before taking up the spun yarn, the fiber thickness unevenness is small between the single fibers or in the longitudinal direction. Since the internal structure is also uniform, stained spots are less likely to occur.

  And after taking up this spun yarn, even when winding it, PET and polylactic acid have good dimensional stability, so that delayed recovery of PTT can be further suppressed, highly uniform undrawn yarn, Or it is preferable because it is easy to obtain a drawn yarn. A false twisted yarn excellent in uniformity and bulkiness can be obtained by applying false twisting to the highly uniform undrawn yarn or drawn yarn thus obtained, which is preferable.

  In the case of a false twisted yarn consisting of conventional PTT alone, the outer diameter in the length direction of the fiber at the stage of the original yarn (undrawn yarn subjected to false twisting or drawn yarn) was non-uniform, Due to the adverse effects such as the occurrence of crimps due to inter-fiber or longitudinal spots, and the occurrence of fluff depending on the processing magnification, the bulky property could not be fully expressed. The crimped yarn of the present invention can eliminate this adverse effect, and thus is preferably a crimped yarn excellent in both uniformity and bulkiness.

  When the core component of the present invention is PET, a copolymerized PET containing other repeating units in addition to the ethylene terephthalate unit may be employed. The melting point of PET consisting only of ethylene terephthalate units is about 254 ° C., which is higher than PTT (melting point 230 ° C.). For this reason, it is preferable to improve the fluidity | liquidity in the suitable melting temperature area | region of PTT. Specifically, PET having a low molecular weight, a copolymerized PET having a melting point lowered by copolymerizing a bend or bulky component such as isophthalic acid or bisphenol A to a dicarboxylic acid component or a glycol component is preferably used. It is preferable to employ PET having an ethylene terephthalate unit of 90 mol% or more in that the polymer has excellent heat resistance, crystallinity, and dimensional stability, and as a result, it is easy to suppress delayed recovery of PTT. More preferably, it is 92 mol% or more, More preferably, it is 95 mol% or more, Especially preferably, it is 98 mol% or more. And it is most preferable that it is PET with low molecular weight in terms of high fluidity in the melting temperature region of PTT.

  Further, in the case of a copolymerized PET having a melting point lowered by copolymerization, the melting point is preferably 200 ° C. or higher, and is preferably 210 ° C. or higher in terms of excellent dimensional stability and easy suppression of delayed recovery of PTT. Is more preferable, and it is further more preferable that it is 220 degreeC or more.

  When the core component is PET, the intrinsic viscosity, which is an index of molecular weight, is preferably 0.6 dl / g or less, more preferably 0.56 dl / g or less, and 0.53 dl / g or less. Is more preferable. In the core component of the present invention, the intrinsic viscosity of PET is preferably 0.4 dl / g or more, in that the heat resistance of the polymer, the strength of the crimped yarn obtained, and the hydrolysis resistance are increased. It is more preferably 43 dl / g or more, and further preferably 0.46 dl / g or more.

  The core component of the present invention is also preferably made of polylactic acid. Here, the polylactic acid is a polymer having-(O-CHCH3-CO) n- as a repeating unit, and means a polymer obtained by polymerizing lactic acid or its oligomer. Since lactic acid has two types of optical isomers, D-lactic acid and L-lactic acid, the polymer is poly (D-lactic acid) consisting only of D isomer and poly (L-lactic acid) consisting only of L isomer, and There is polylactic acid consisting of both. As the optical purity of D-lactic acid or L-lactic acid in polylactic acid is lowered, the crystallinity is lowered and the melting point is lowered. Since the higher the crystallinity of polylactic acid, the easier the delayed recovery of PTT can be suppressed by the effect of the core component, the optical purity is preferably 90% or more. A more preferred optical purity is 93% or more, a further preferred optical purity is 97% or more, and a particularly preferred optical purity is 99.5% or more. As described above, the optical purity has a strong correlation with the melting point. The optical purity is about 90%, the melting point is about 150 ° C., the optical purity is 93%, the melting point is about 160 ° C., the optical purity is 97%, and the melting point is about 170 ° C. It becomes.

  In addition to the system in which two types of optical isomers are simply mixed as described above, the two types of optical isomer polymers are blended and arranged as a core component, and then subjected to high-temperature heat treatment at 140 ° C. or higher. A stereocomplex in which a racemic crystal is formed is preferable because the melting point can be increased to 220 to 230 ° C. and the crystal structure has a high stability, so that the delayed recovery of PTT can be further suppressed. In this case, the core component refers to a mixture of poly-L lactic acid and poly-D lactic acid, and a blend ratio of 40/60 to 60/40 is preferable because the ratio of stereocomplex crystals can be increased.

  In addition, residual monomers such as lactide are present in polylactic acid, but these low molecular weight residues are preferred because they promote the hydrolyzability of the crimped yarn and reduce durability. Is 1% by weight or less, more preferably 0.5% by weight or less, and still more preferably 0.2% by weight or less.

  The polylactic acid may be a copolymer obtained by copolymerizing components other than lactic acid within a range that does not impair the properties of polylactic acid, for example. The components to be copolymerized include polyalkylene ether glycols such as polyethylene glycol, aliphatic polyesters such as polybutylene succinate and polyglycolic acid, aromatic polyesters such as polyethylene isophthalate, and hydroxycarboxylic acids, lactones, dicarboxylic acids, and diols. An ester bond-forming monomer such as Among these, polyalkylene ether glycol is preferable. However, the higher the crystallinity of polylactic acid, the easier it is to suppress delayed recovery of PTT due to the effect of the core component, so the copolymerization ratio of such copolymerization component is 0.1 to 10 mol% with respect to polylactic acid. It is preferable. Polylactic acid may further contain additives such as particles, crystal nucleating agents, flame retardants, plasticizers, antistatic agents, antioxidants, ultraviolet absorbers, and crosslinking agents as modifiers.

  Here, when the core component of the crimped yarn of the present invention is polylactic acid, the point to be particularly noted is that the heat resistance of polylactic acid is not so high, and thermal decomposition occurs during melting and storage, and the molecular weight tends to decrease. It is. In the melt spinning, drawing process, and false twisting process, oriented crystallization of polylactic acid can be promoted, the crystallinity of polylactic acid is increased, and the delayed recovery of PTT can be further suppressed, so that the molecular weight of polylactic acid is high. preferable. Further, as will be described later, it is preferable to use polylactic acid having a high molecular weight as the core component from the viewpoint of easily suppressing the deformation of the cross section in the false twisting process and avoiding unintentional uneven distribution of the core component.

  Specifically, the weight average molecular weight is preferably 100,000 or more, more preferably 120,000 or more, further preferably 140,000 or more, and particularly preferably 160,000 or more. However, as described above, the weight average molecular weight is preferably 270,000 or less, more preferably 260,000 or less, and 250,000 or less in that the molding process within the proper melting temperature range of PTT is possible. More preferably. The said weight average molecular weight is the value calculated | required by gel permeation chromatography (GPC) using the method as described in an Example, and calculated | required in polystyrene conversion.

  The crimped yarn of the present invention needs to be composed of a core-sheath composite fiber. By forming all of the fiber surface with polytrimethylene terephthalate as a core-sheath composite fiber, a crimped yarn excellent in moisture and heat aging resistance can be obtained. The cross-sectional shape of the crimped yarn may be any of a round cross-section, a polygon cross-section, a multi-leaf cross-section, a hollow cross-section, and other known cross-sectional shapes. Although it may be a structure, it has a round cross section and a single-core core-sheath structure is preferred in that it is more excellent in heat and heat aging resistance, easily improves the bulkiness of the crimped yarn, and is excellent in durability against external force.

  The crimped yarn of the present invention refers to a generally known crimped yarn such as false twisted yarn, bimetal crimped yarn, mechanical crimped yarn, BCF yarn, etc. It is a fiber having bulkiness due to entanglement. The crimped yarn of the present invention is preferably a false twisted yarn because it has higher bulkiness and can easily form a crimped yarn with uniform crimp between single fibers. False twisted yarn is one-twisted to a multifilament in the manufacturing process, heat treated, and then untwisted to express the bulkiness, so that mechanical forces such as twisting and unwinding are easily applied evenly between single fibers. It is preferable because it is easy to obtain a crimped yarn having high bulkiness and high uniformity.

  The crimped yarn of the present invention may be a filament yarn (long fiber), or may be a staple yarn (short fiber) obtained by cutting the crimped yarn into an appropriate length. Is a crimped yarn composed of converged multifilament yarns, so that a fiber structure with high surface smoothness can be obtained, the irritation of the surface of the fiber structure can be reduced, and drug loading It is preferable because it is excellent. Further, the filament yarn is preferable because the core component is not exposed, and the characteristics of polytrimethylene terephthalate which are excellent in moisture and heat aging resistance can be utilized to the maximum, and the moisture and heat aging resistance is excellent.

  In the crimped yarn of the present invention, the weight fraction of the core component needs to be 20 to 40% by weight. In order to suppress the delayed recovery of PTT, the weight fraction of the core component needs to be 20% by weight or more based on the total weight of the single fibers. It is preferable that the core component is contained in an amount of 20% by weight or more, since the uniformity of the crimped yarn is remarkably increased, and it is excellent in leveling even as a high-bulky false twisted yarn. More preferably, it is 22 weight% or more, More preferably, it is 25 weight% or more. Further, in order to make the best use of the characteristics of PTT such as low modulus, elastic recovery, high bulkiness, and hydrolysis resistance, the weight fraction of the core component needs to be 40% by weight or less. Moreover, since the area of the core-sheath interface (interface between the core component and the sheath component) per unit volume of the core component is increased by setting the weight fraction of the core component to 40% by weight or less, the crimped yarn can be bent or Even when deformation such as elongation is applied, or when wet heat treatment is applied in the dyeing step, the core-sheath interface does not peel off, which is preferable because durability against external force is extremely excellent. More preferably, it is 38 weight% or less, More preferably, it is 35 weight% or less.

  In the present invention, as described above, a core-sheath composite yarn is used, and by containing 20 to 40% by weight of a polyester other than polytrimethylene terephthalate as a core component, delayed recovery of PTT is suppressed in the spinning and drawing processes. An undrawn yarn and a drawn yarn excellent in uniformity can be obtained. For this reason, it is possible to maximize the bulkiness in the false twisting process, and to obtain a crimped yarn having both uniformity and bulkiness. As a new merit of these synergistic effects, it is possible to form undrawn yarns and drawn yarns with excellent uniformity, and PTT has excellent elastic recovery, and the outer diameter spots in the fiber length direction become healthy. Even a crimped yarn having a small single fiber fineness can be made into a crimped yarn having a leveling property and a bulky property suitable for practical use.

  That is, a crimped yarn having a small single fiber fineness, generally made of PET, can form a soft touch fabric, but it is a crimped yarn having a high bulkiness due to the crimping due to the processing tension applied in the manufacturing process. Or the thinning becomes unstable in the melt spinning process, and the uniformity of the fiber becomes a problem. On the other hand, the crimped yarn composed of the core-sheath composite fiber of the present invention has a bulky property because it is difficult to loosen due to the elastic recovery characteristics of PTT even if the crimped yarn has a small single fiber fineness. Since the core-sheath composite fiber is good, it is a crimped yarn with good fiber uniformity.

  In addition, when the knitted fabric is configured as a crimped yarn having a smaller single fiber fineness, a knitted fabric having a low modulus and good product quality is obtained by expanding the inter-fiber gap between multifilaments and between the multifilaments. Since the ground is obtained, it is preferable. Therefore, the single fiber fineness is preferably 1.8 dtex or less, more preferably 1.7 dtex or less, and further preferably 1.6 dtex or less. However, if the single fiber fineness is too small, the bulkiness tends to decrease, so the single fiber fineness is preferably 0.1 dtex or more, more preferably 0.3 dtex or more, and 0.5 dtex or more. Is more preferable.

  The crimped yarn of the present invention is preferably a crimped yarn having a high bulky property and having a stretch recovery rate (CR) in the range of 25 to 60%, which is an index representing the bulky property of the crimped yarn. A knitted fabric composed of a crimped yarn having a high CR is preferable because it has a low modulus and is highly elastic. On the other hand, when CR exceeds 60%, the strength of the crimped yarn is lowered, and the process passability may be hindered when forming a knitted fabric. For this reason, CR is more preferably 35 to 57%, further preferably 40 to 55%. CR can be measured based on the method described in Examples. In the crimped yarn of the present invention, since the content of polyester other than polytrimethylene terephthalate constituting the core component is 40% by weight or less, a high bulky property is exhibited without inhibiting the crimping property of PTT. be able to. In addition, since the core component contains 20% by weight or more, a highly uniform crimped yarn can be obtained, so that even with a high bulky crimped yarn as described above, a fiber structure with good leveling and surface quality can be obtained. is there. In order to make CR within the above range, it is preferable to adjust the molecular weight of PTT, the content of the core component, the polyester type and molecular weight of the core component, the spinning speed, false twisting conditions, etc. in the production process.

  Moreover, it is preferable that the 10% stretch elastic recovery rate which is an index of the elastic recoverability of the crimped yarn is 70% or more from the viewpoint that the elastic recoverability of the fiber structure is enhanced. More preferably, it is 80% or more, More preferably, it is 90% or more. The 10% stretch elastic recovery rate of the crimped yarn can be measured based on the method described in Examples. In order to obtain a crimped yarn having a high 10% elongation elastic recovery rate, it is preferable that the core component content is low, the CR is high, and the molecular weight and molecular orientation of PTT are high.

  The crimped yarn of the present invention needs to have an irregularity in the cross section of the single fiber of 1.5 or less. When the degree of irregularity is 1.5 or less, the smoothness of the surface when the fiber structure is formed is improved, and there is no roughness and the fiber structure is soft touch and less irritating. Thus, for the first time, surface quality that can be suitably used for fiber structures used in low-weight applications, such as a patch base fabric, is achieved. In addition, by making the degree of deformity of the single fiber 1.5 or less, the external force applied to the crimped yarn is less likely to concentrate on the core-sheath interface, and the crimped yarn has excellent durability that prevents the core-sheath interface from peeling off. It is preferable because there is a merit that For this reason, the degree of deformity is preferably low, preferably 1.4 or less, more preferably 1.3 or less, further preferably 1.2 or less, and particularly preferably 1.1 or less.

  By the way, it was described above that a false twisted yarn is preferable in order to obtain a crimped yarn having high bulkiness. However, in false twisting, crimping occurs when the heated multifilament is twisted under high tension, and the single fibers that make up the multifilament are densely packed. As a result, the cross section was deformed, and the degree of deformity was likely to increase as described above. And the false twisted yarn whose cross section of the single fiber has been deformed and thus has a high degree of deformity is not a problem when applied to a relatively high weight application such as clothing. It was found that when it is used for an application having a low basis weight such as an agent base fabric, an adverse effect due to an increased degree of deformity becomes obvious. Specifically, there is a problem that the leveling property of the fiber structure is insufficient, or the surface is roughened to irritate the skin.

  In the false twisting process, the yarn temperature is increased or the processing magnification is increased to obtain a crimped yarn having a high CR. In particular, in a crimped yarn composed of a core-sheath composite yarn, a sheath component and a core are obtained. Since the viscoelastic characteristics differ from the components, the cross section was crushed and deformed easily when only one side component was softened. For this reason, it was necessary to devise in order to obtain a crimped yarn composed of single fibers having a small degree of deformity. And as a result of intensive studies by the present inventors in order to relieve the deformation of the cross section in the false twisting process, in addition to making the core component content 40% by weight or less, production conditions such as spinning conditions and false twisting conditions Was found to be a crimped yarn having an irregularity of 1.5 or less for the first time by making the preferred range in the present invention, and the present invention was completed. The reason why it is possible to reduce the degree of deformity of the single fiber due to the low weight fraction of the core component is not certain, but PTT is probably a polymer with extremely excellent elastic recovery, so the weight fraction of the core component is low, that is, PTT When the weight fraction is high, even if the cross-section of the single fiber is deformed densely during false twisting and the cross-section of the single fiber is deformed, the sheath component shows elastic recovery after the compressive force is solved, and the cross-section is relieved It is estimated. Furthermore, it is important that the core component is arranged in the center of the single fiber at the stage of the raw yarn to be used in the false twisting process, so that the compressive force applied by false twist is uniformly dispersed in the sheath component, which is deformed This is preferable because a crimped yarn having a small degree can be obtained. In addition, various conditions in spinning and false twisting, such as forming PTT microcrystals in the raw yarn stage and suppressing the first heater temperature in false twisting to an appropriate temperature, are within the preferred range in the present invention. Thus, for the first time, a crimped yarn having a small degree of deformation is obtained. The higher the molecular weight of PTT, the higher the molecular weight of polylactic acid when the core component is a crimped yarn made of polylactic acid.

  The crimped yarn of the present invention has a small deviation between the center of gravity of the core component and the center of gravity of the single fiber in the single fiber cross section, and the sheath component PTT has a uniform thickness over the outline of the single fiber cross section. It is preferable that they are arranged. This is preferable because durability against external force of the knitted fabric using the crimped yarn, hydrolysis resistance, and surface quality of the base fabric are further improved.

  For such a crimped yarn with a small deviation between the center of gravity of the core component and the center of gravity of the single fiber, the raw yarn composed of the single fiber in which the core component is arranged at the center of the single fiber is subjected to crimping. Can be obtained. However, the core-sheath composite fiber whose sheath component is made of PTT is a raw yarn used for false twisting if the melt spinning conditions, the molecular weight of PTT, or the polyester other than polytrimethylene terephthalate as the core component are insufficiently designed. At this stage, the core component may be unevenly distributed without intention in the cross section of the single fiber. And since PTT is a polymer excellent in elastic recoverability, it has been found that even if the center of gravity of the core component and the center of gravity of the single fiber are slightly shifted, spiral crimp is likely to occur in the single fiber. Of course, for example, it is not a problem if the bimetallic crimped yarn is a bicomponent crimped yarn in which all the single fibers have a uniform spiral crimp, but a two-component polymer is joined. If a single fiber that is highly unevenly distributed exists in the filament, it becomes a crimped yarn in which a single fiber that does not have spiral crimps and a single fiber that has spiral crimps coexist, resulting in a fiber structure. In this case, streaky stained spots are incurred and a rough feeling is given to the surface.

  In addition, when false twisting is performed on a single yarn composed of a single fiber whose core component has been unevenly distributed in the spinning process, the cross-section is likely to be deformed by the compressive force by which the multifilaments in the false twisting process are closely packed. Also, it has a drawback that it is easy to become a crimped yarn having a high degree of deformation. Due to this influence, the compressive force applied to each single fiber is biased, causing crimped spots and thickness spots in the longitudinal direction of the fibers and between the single fibers. Therefore, the crimped yarn including the single fiber in which the core component is unevenly distributed contains a single fiber having a spiral crimp and a single fiber having a large degree of irregularity. When trying to form a body, it appears as a streak after dyeing, or the surface becomes rough and becomes a defect of the product.

  When the distance between the center of gravity of the core component and the center of gravity of the single fiber is increased with respect to the diameter of the single fiber, the bias of elastic recovery in the single fiber cross section increases, and spiral crimp occurs. For this reason, it is preferable that the center-of-gravity dissociation degree calculated by dividing the distance between the center of gravity of the core component and the center of gravity of the single fiber by the diameter of the single fiber in the cross section of the single fiber is 0.1 or less. . It is more preferably 0.08 or less, further preferably 0.06 or less, and particularly preferably 0.04 or less. 0% is ideal and best. The center-of-gravity dissociation degree of the present invention refers to the center-of-gravity dissociation degree of a single fiber of crimped yarn, and can be determined by the method described in the examples.

  As a result of intensive studies by the present inventors, the crimped yarn whose sheath component is PTT for the first time is selected by selecting the production conditions (spin block temperature, discharge linear velocity) in the melt spinning process within a preferable range in the present invention. It was found that the uneven distribution of the core component can be suppressed. Moreover, it turned out that there exists a merit which can suppress uneven distribution of a core component by making content of a core component into a small amount component like this invention, and making content of a sheath component into a large amount component. Further, the degree of dissociation of the center of gravity of the crimped yarn of the present invention can be reduced by selecting the molecular weight of PTT and the type and molecular weight of the polyester constituting the core component within the above-described ranges.

  The sheath component is a core-sheath composite fiber composed of PTT, and the reason why the core component is likely to be unevenly distributed unintentionally is probably because the heat resistance of PTT is not so high as described above, and the molecular weight is lowered during melting storage and the molecular weight distribution. In addition to the fact that the melt shear viscosity tends to change depending on the shear rate and temperature, the heat history received in the polymer pipe, the spin pack, and the spinneret discharge hole in the melt spinning process due to the characteristics of the PTT that the melt shear viscosity easily changes depending on the shear rate and temperature. It is presumed that the melt viscosity of PTT fluctuates even with a slight difference in the shear history, and the melt viscosity distribution tends to occur in the sheath component of the spun yarn.

  From the above, the crimped yarn of the present invention is more preferable as it does not contain a single fiber having a spiral crimp, because the quality of the product in the case of a knitted fabric becomes better. For this reason, in all the single fibers constituting the multifilament, the ratio including the single fibers having spiral crimp is preferably 5% or less, more preferably 4% or less, and more preferably 3% or less. More preferably, it is more preferably 2% or less. 0% is ideal and best. The ratio including the single fiber having the spiral crimp can be measured by the method of the example.

  The crimped yarn of the present invention preferably has 2% or less of Worcester spots (U%), which is an index of thickness spots in the longitudinal direction of the multifilament. Thereby, the leveling property of a knitted fabric can be improved. The Worcester plaque U% is more preferably 1.5% or less, further preferably 1% or less, and most preferably 0.6% or less.

  The crimped yarn of the present invention is preferable because it is a crimped yarn having a small thickness unevenness between single fibers, and is excellent in leveling and has a soft surface without surface roughness. For this reason, the fineness CV%, which is an index of thickness unevenness between single fibers, is preferably 5% or less, more preferably 4% or less, further preferably 3% or less, and further preferably 2% or less. It is particularly preferred that The fineness CV% can be measured by the method of the example.

  Both U% and fineness CV% are indices representing the thickness unevenness of the crimped yarn. The former reflects the thickness unevenness of the multifilament in the longitudinal direction, whereas the latter reflects the cross section of the multifilament. The difference is that it reflects the thickness variation between the single fibers in the direction. For example, as described above, in the case of a crimped yarn composed of a single component of PTT, the single fibers are compressed toward the inner layer by tightening due to delayed recovery, and therefore, the fineness CV% tends to deteriorate step by step. . As a result, the crimped yarns in the inner and outer layers tended to have a dyeing difference in stages.

  The crimped yarn of the present invention includes 20 to 40% by weight of polyester other than polytrimethylene terephthalate as a core component, thereby reducing the thickness unevenness between single fibers by suppressing the delayed recovery of PTT. . In order to further reduce the fineness CV of the crimped yarn of the present invention, the weight fraction of the core component, the type and molecular weight of the polyester constituting the core component are selected within the above-described ranges, and the delayed recovery of PTT is suppressed. It is preferable. At the same time, the preferred range of the melt spinning conditions in the present invention is selected to make a crimped yarn that does not contain a spiral crimped single fiber, or the conditions for drawing and false twisting are set in the preferred range to suppress the occurrence of fuzz and the like. It is also preferable to take measures.

  The lower the modulus of the crimped yarn of the present invention, the lower the modulus of the knitted fabric. Therefore, the modulus of the crimped yarn is preferably 40 cN / dtex or less, more preferably 37 cN / dtex or less, and further preferably 35 cN / dtex or less. On the other hand, if the modulus of the crimped yarn is too low, when the knitted fabric is bent and stretched, the structure of the base fabric may be disturbed due to the binding force between the multifilaments, so The modulus is preferably 20 cN / dtex or more, more preferably 23 cN / dtex or more, and further preferably 25 cN / dtex or more. The modulus of the crimped yarn can be controlled by selecting the content of the core component, the polyester type of the core component, and the molecular weight within a preferable range.

  If the strength of the crimped yarn of the present invention is 1.5 cN / dtex or more, a knitted fabric having a practical level of strength can be formed, and the process passability in the production process is improved, which is preferable. More preferably, it is 1.8 cN / dtex or more, More preferably, it is 2.0 cN / dtex or more. There is no upper limit because the higher the strength of the crimped yarn is, the higher the technical limit is about 4.0 cN / dtex.

  Moreover, if the elongation of the crimped yarn of the present invention is 20 to 60%, it is preferable because the balance between strength and elongation is excellent and the permeability in the production process is increased. More preferably, it is 30 to 50%.

  It is preferable that the boiling water shrinkage of the crimped yarn of the present invention is 2 to 20%. A higher boiling water shrinkage ratio is preferable because the bulkiness is easily exhibited in the dyeing process, steam treatment, and the like. Further, by suppressing the boiling shrinkage rate to an appropriate range, the dimensional stability of the knitted fabric is enhanced, and at the same time, the surface is not coarsely cured and the surface quality is good, which is preferable. The boiling water shrinkage is preferably 3 to 16%, more preferably 4 to 12%.

  Further, the crimped yarn of the present invention preferably has a residual torque of 200 T / m or less. If the residual torque is 200 T / m or less, the warp of the yarn unwound from the cheese is suppressed and the running stability is excellent, so that the knitting property of the knitted fabric is improved. Furthermore, skew, weft, and streak can be suppressed in the resulting knitted fabric, which is preferable. The residual torque is more preferably 150 T / m or less, and still more preferably 100 T / m or less. In addition, if the residual torque is 20 T / m or more, stable production is possible, and the influence on the quality of the final product is slight, which is preferable.

  The crimped yarn of the present invention is preferably used after dyeing because the crimped yarn is excellent in levelness, and is preferable because the bulky property of the crimped yarn is sufficiently manifested during wet heat treatment in the dyeing process. . Of course, it can also be used without staining, but in this case, it is also preferable to perform boiling water treatment or steam treatment for the purpose of revealing the bulkiness. The dyeing process may be performed at any stage, and can be dyed in a cheese shape or a cloth shape with a dyeing machine such as a cheese dyeing machine, a liquid dyeing machine, or a drum dyeing machine. In addition, it may be an original crimped yarn colored by adding an organic and / or inorganic pigment to the core-sheath composite fiber at any stage before melt spinning.

  In addition, the crimped yarn of the present invention is preferable because the hydrolysis resistance increases as the total carboxyl end group concentration decreases. It is preferably 30 eq / ton or less, more preferably 20 eq / ton or less, and even more preferably 10 eq / ton or less. Since cyclic oligomers and residual oligomers such as lactide also generate carboxyl group terminals by hydrolysis, the total carboxyl terminal amount including not only the carboxyl group terminals of the polymer but also those derived from the residual oligomers and monomers is important. In order to obtain a crimped yarn having a low total carboxyl end group concentration, a polymer having a low carboxyl end group concentration can be prepared, a sheath component and / or a core component at the stage of producing a polymer as a raw material of the crimped yarn. It is possible to adopt a method in which an end-blocking agent is contained.

  The terminal blocking agent is not particularly limited as long as it is a compound having a reactive group rich in reactivity with a carboxyl terminal group or a polymer. The crimped yarn of the present invention is excellent in interfacial adhesion between the PTT and the core component, and thus exhibits sufficient durability against external force as it is. For example, in the production process, two or more active hydrogen reactivities in one molecule By adding a terminal blocking agent having a group, the terminal blocking agent reacts with the sheath component and the carboxyl terminal group of the core component, and thus there is a merit that the adhesion at the core-sheath interface is further increased, which is preferable.

  Here, the active hydrogen reactive group is one having reactivity with a COOH end group present at the terminal of a polylactic acid resin or a thermoplastic polyamide resin. For example, a glycidyl group, an oxazoline group, a carbodiimide group, an aziridine group, an imide Group, isocyanate group, maleic anhydride group and the like are preferably used. Among the reactive groups, a glycidyl group, an oxazoline group, a carbodiimide group, an acid anhydride group (a group formed from maleic anhydride (sometimes referred to as a maleic anhydride group), etc.) is preferably used, and in particular, a glycidyl group or a carbodiimide. A group is preferably used.

  If the number of the reactive groups is one or more, the role as a terminal blocking agent can be satisfied. And if it is two or more, the role which improves the adhesiveness of a core-sheath interface can also be satisfy | filled. On the other hand, if there are more than 20 reactive groups in one molecule, the viscosity tends to be excessively increased during spinning and the spinnability tends to decrease. Therefore, the number of active hydrogen reactive groups in one molecule is one. More than 20 and 20 or less are preferable. More preferably, it is 10 or less, and more preferably 3 or less. Moreover, the kind of reactive group in one molecule may include a plurality.

  For example, when a terminal blocker having a reactive group is a copolymer obtained by graft copolymerization of a side chain having a reactive group on the main chain of the polymer, a large number of functional groups may be introduced into one molecule. In addition to being possible, the thermal properties such as the melting point are generally stable, which is preferable. The polymer to be the main chain to which this reactive group is grafted can be arbitrarily selected, but for ease of synthesis, polyester polymer, polyacrylate, polymethyl methacrylate, poly (alkyl) meta. It can be appropriately selected from the group of acrylate polymers such as acrylate, polystyrene polymers, polyolefin polymers and the like.

  Among end-capping agents that can be used in the present invention, those having a glycidyl group include, for example, a polymer having a monomer unit of a compound having a glycidyl group, or a glycidyl group graft-polymerized to a main chain polymer. The compound which is superposed | polymerized and also what has a glycidyl group at the terminal of a polyether unit are mentioned. Examples of the monomer unit having a glycidyl group described above include glycidyl acrylate and glycidyl methacrylate. In addition to these monomer units, a long-chain alkyl acrylate or the like may be copolymerized to control the reactivity of the glycidyl group. In addition, when the polymer having a glycidyl group as a monomer unit or the weight average molecular weight of the polymer as the main chain is in the range of 250 to 30,000, the melt viscosity is increased when a high concentration is added. This is preferable because it can be suppressed. The weight average molecular weight is more preferably in the range of 250 to 20,000.

  In addition, a compound having two or more glycidyl units in the triazine ring is preferable because of high heat resistance. For example, triglycidyl isocyanurate (TGIC), monoallyl diglycidyl isocyanurate (MADGIC) and the like are preferably used.

  Of the end-capping agents that can be used in the present invention, compounds having an oxazoline group, a carbodiimide group, an aziridine group, an imide group, an isocyanate group, and a maleic anhydride group can be used in the same manner. Among the above, those having a carbodiimide group are more preferable because of extremely excellent low-temperature reactivity. For example, examples of the carbodiimide compound include diphenylcarbodiimide, di-cyclohexylcarbodiimide, di-2,6-dimethylphenylcarbodiimide, diisopropylcarbodiimide, dioctyldecylcarbodiimide, di-o-toluylcarbodiimide, di-p-toluylcarbodiimide, di- p-nitrophenylcarbodiimide, di-p-aminophenylcarbodiimide, di-p-hydroxyphenylcarbodiimide, di-p-chlorophenylcarbodiimide, di-o-chlorophenylcarbodiimide, di-3,4-dichlorophenylcarbodiimide, di -2,5-dichlorophenylcarbodiimide, p-phenylene-bis-o-toluylcarbodiimide, p-phenylene-bis-dicyclohexylcarbodiimide, p-phene Len-bis-di-p-chlorophenylcarbodiimide, 2,6,2 ', 6'-tetraisopropyldiphenylcarbodiimide, hexamethylene-bis-cyclohexylcarbodiimide, ethylene-bis-diphenylcarbodiimide, ethylene-bis-dicyclohexylcarbodiimide N, N′-di-o-triylcarbodiimide, N, N′-diphenylcarbodiimide, N, N′-dioctyldecylcarbodiimide, N, N′-di-2,6-dimethylphenylcarbodiimide, N-triyl- N′-cyclohexylcarbodiimide, N, N′-di-2,6-diisopropylphenylcarbodiimide, N, N′-di-2,6-di-tert-butylphenylcarbodiimide, N-toluyl-N′-phenylcarbodiimide, N, N'-Di-p- Nitrophenylcarbodiimide, N, N'-di-p-aminophenylcarbodiimide, N, N'-di-p-hydroxyphenylcarbodiimide, N, N'-di-cyclohexylcarbodiimide, N, N'-di-p-toluyl Carbodiimide, N, N′-benzylcarbodiimide, N-octadecyl-N′-phenylcarbodiimide, N-benzyl-N′-phenylcarbodiimide, N-octadecyl-N′-tolylcarbodiimide, N-cyclohexyl-N′-tolylcarbodiimide, N-phenyl-N'-tolylcarbodiimide, N-benzyl-N'-tolylcarbodiimide, N, N'-di-o-ethylphenylcarbodiimide, N, N'-di-p-ethylphenylcarbodiimide, N, N ' -Di-o-isopropylphenylcarbodiimide N, N'-di-p-isopropylphenylcarbodiimide, N, N'-di-o-isobutylphenylcarbodiimide, N, N'-di-p-isobutylphenylcarbodiimide, N, N'-di-2,6- Diethylphenylcarbodiimide, N, N'-di-2-ethyl-6-isopropylphenylcarbodiimide, N, N'-di-2-isobutyl-6-isopropylphenylcarbodiimide, N, N'-di-2,4,6 Mono- or dicarbodiimide compounds such as trimethylphenylcarbodiimide, N, N′-di-2,4,6-triisopropylphenylcarbodiimide, N, N′-di-2,4,6-triisobutylphenylcarbodiimide, poly ( 1,6-hexamethylenecarbodiimide), poly (4,4'-methylenebiscyclohexylca) Rubodiimide), poly (1,3-cyclohexylenecarbodiimide), poly (1,4-cyclohexylenecarbodiimide), poly (4,4'-diphenylmethanecarbodiimide), poly (3,3'-dimethyl-4,4'- Diphenylmethanecarbodiimide), poly (naphthylene carbodiimide), poly (p-phenylenecarbodiimide), poly (m-phenylenecarbodiimide), poly (tolylcarbodiimide), poly (diisopropylcarbodiimide), poly (methyl-diisopropylphenylenecarbodiimide), poly ( And polycarbodiimides such as triethylphenylenecarbodiimide) and poly (triisopropylphenylenecarbodiimide). Among them, polymers of N, N′-di-2,6-diisopropylphenylcarbodiimide and 2,6,2 ′, 6′-tetraisopropyldiphenylcarbodiimide are mentioned, and among these, the heat resistance is high and the thermal decomposition is difficult, and the reaction In particular, “Carbodilite HMV-8CA” manufactured by Nisshinbo Co., Ltd., “Carbodilite HMV-8PI” manufactured by Nisshinbo Co., Ltd., and “Carbodilite LA-1” manufactured by Nisshinbo Co., Ltd. are particularly preferably used. .

  The crimped yarn of the present invention includes, for example, antioxidants and heat stabilizers (hindered phenols, hydroquinones, phosphites and their substitutes, copper halides, iodine compounds, etc.), weathering agents (resorcinols, Salicylates, benzotriazoles, benzophenones, hindered amines, etc.), pigments (cadmium sulfide, phthalocyanine, carbon black, etc.), gloss improvers (titanium oxide, calcium carbonate, etc.), dyes (nigrosine, aniline black, etc.), crystal nuclei Agents (talc, silica, kaolin, clay, etc.), plasticizers (octyl p-oxybenzoate, N-butylbenzenesulfonamide, etc.), antistatic agents (alkyl sulfate type anionic antistatic agents, quaternary ammonium salt type cations Antistatic agent, polyoxyethylene sorbitan monoste Nonionic antistatic agents such as rate, betaine amphoteric antistatic agents, etc.), flame retardants (hydramines such as melamine cyanurate, magnesium hydroxide, aluminum hydroxide, ammonium polyphosphate, brominated polystyrene, brominated Polyphenylene oxide, brominated polycarbonate, brominated epoxy resin, or a combination of these brominated flame retardants and antimony trioxide).

  Next, a fiber structure comprising the crimped yarn of the present invention will be described.

  The crimped yarn of the present invention can be used as a conventionally known fiber structure (woven fabric, knitted fabric, nonwoven fabric, etc.). However, a knitted fabric is preferable in order to make the best use of the low modulus property and elastic recovery property of the crimped yarn.

  Examples of the knitted fabric in the present invention include a circular knitted fabric, a flat knitted fabric, and a warp knitted fabric, and examples thereof include a single tricot, a double tricot, a single raschel, a double raschel, a single circular knitted fabric, and a double circular knitted fabric. Further, the structure of the knitted fabric is not particularly limited, and examples thereof include tendon, kaka, interlock, mesh, single-sided unevenness for circular knitted fabrics, and half, satin, mesh, single-sided unevenness for warp knitted fabrics. In particular, when used as a patch base fabric, a circular knitted fabric is preferable. Further, the double-sided knitting is preferable because the ear portion does not curl when the circular knitted fabric is opened, and the surface smoothness is enhanced. An interlock knitted fabric is particularly preferable in that the degree of freedom of the knitting structure is large and a low modulus is easily obtained.

  The knitted fabric of the present invention contains 50% by weight or more of the crimped yarn of the present invention based on the total weight of the knitted fabric in order to make use of the excellent low modulus property and elastic recovery of the crimped yarn of the present invention. It is preferable that it is 70% by weight or more. It is particularly preferable that 90% by weight or more is made of the crimped yarn of the present invention.

  The knitted fabric of the present invention may contain other fibers (synthetic fibers or natural fibers) in the knitted fabric comprising the crimped yarn of the present invention or separately from the knitted fabric, and a substrate other than the fibers. (A film, a sheet, etc.) may be included. For example, when mixed with other fibers, synthetic fibers made of a fiber-forming polymer such as polyester fiber, nylon fiber, acrylic fiber, vinylon fiber, polypropylene fiber, polyethylene fiber, regenerated fiber such as rayon, acetate, etc. Semi-synthetic fibers and natural fibers such as wool, silk, cotton and hemp are used. For example, when mixed with other films and sheets, films and sheets of polyethylene, polypropylene, polyester, polyamide, vinyl chloride, polyvinylidene chloride, polyurethane, and the like are employed. The method of mixing with other fibers is arbitrary, such as knit, knitting, blending, blending, and twisting. Moreover, when mixing with another base material, methods, such as heat molding and adhere | attaching with an adhesive agent, can also be employ | adopted.

Since the knitted fabric of the present invention includes a crimped yarn excellent in uniformity and bulkiness, it is preferable because it has sufficient product quality even as a knitted fabric having a basis weight of 400 g / m ³ or less. For this reason, like a patch base fabric, it is suitably used as a low-density knitted fabric.

  The patch base fabric will be described. The patch base fabric referred to in the present invention refers to a structure comprising a conventionally known fiber structure (woven fabric, knitted fabric, non-woven fabric, etc.), such as a haptic agent, a plaster agent, a syrup agent, and a hot compress for anti-inflammatory analgesia. It is used as a base material for patches that are applied to humans or animals for a certain period of time, such as cold compresses and tapes used for sports and body protection, and then peeled off after use.

  And by constructing the patch base fabric with a knitted fabric comprising the crimped yarn of the present invention, it has a low modulus that is not found in a patch base fabric composed of a conventional crimped yarn made of PET, A patch base fabric excellent in elastic recovery can be obtained. In addition, since it is excellent in leveling, soft touch and surface smoothness, comfort during wearing is remarkably improved, which is preferable. In addition, since it is excellent in drug carrying properties, chemical resistance, hydrolysis resistance, heat resistance, and durability against external force, it can be suitably used for a wide range of uses as a patch base fabric.

The patch base fabric made of the knitted fabric of the present invention preferably has a basis weight of 20 to 200 g / m ² . The larger the basis weight, the better the strength of the patch, the elastic recovery property, and the drug carrying property. On the other hand, the lower the basis weight, the lower the modulus and the better the followability to the skin. More preferably, it is 30-170 g / m < ² >, More preferably, it is 40-150 g / m < ² >.

  In addition, the lower the density of the knitted fabric, the lower the modulus of the patch base fabric, which is preferable. However, when the density is too low, the knitted fabric is transparent and may be inferior in drug carrying properties when used as a patch base fabric. . Therefore, the course which is a series of fibers constituting the knitted fabric is preferably 10 to 70 course / inch, and more preferably 20 to 60 course / inch. Further, for the same reason, the well showing the longitudinal arrangement of the fibers constituting the knitted fabric is preferably 10 to 70 well / inch, and more preferably 20 to 60 well / inch.

  The patch base fabric composed of the fiber structure of the present invention is preferably stretched with a low stress, that is, has a low modulus, with less resistance to the skin. For this reason, it is preferable that the tension at 50% elongation as measured by a 25 mm width (vertical and horizontal), which is an index of modulus, is preferably 10N or less, more preferably 8N or less, and even more preferably 5N or less. On the other hand, a moderately high modulus is preferable because when the release film is peeled off from the patch and applied to the skin, the base fabric is excellent in handleability without being bent or slackened. Therefore, the tension at 50% elongation is preferably 0.1 N or more, more preferably 0.3 N or more, and further preferably 0.5 N or more. In order to lower the tension at 50% elongation of the patch base fabric, the more the low modulus crimped yarn of the present invention is contained, the lower the modulus of the crimped yarn of the present invention, the higher the CR, The lower the basis weight of the base fabric, the lower it can be made.

  The patch base fabric composed of the fiber structure of the present invention preferably has a 50% stretch elastic recovery rate of 80% or more measured at a width of 25 mm. The higher the 50% elongation elastic recovery rate, the better the elastic recovery of the patch, and even when the bending and stretching movements are repeated, wrinkles do not occur and the resistance to the skin is small, which is preferable. More preferably, it is 85% or more, further preferably 90% or more, and particularly preferably 95% or more. The 50% stretch elastic recovery rate of the patch base fabric includes a large amount of the crimped yarn of the present invention excellent in elastic recoverability, and the higher the 10% stretch elastic recovery rate of the crimped yarn of the present invention, the higher the patch base fabric. The higher the basis weight, the higher it can be.

  Further, the closer the vertical properties of the patch base fabric are, the easier it is to follow various skin movements and the better the feeling of wearing is preferred. For this reason, in order to bring the vertical and horizontal properties of the patch base fabric closer, after adjusting the well / course of the knitted fabric before dyeing in advance, a device such as bringing the vertical and horizontal properties of the patch base fabric after the dyeing treatment closer is also preferable. .

  The patch of the present invention comprises at least the patch base fabric of the present invention. And it comprises at least a patch base fabric, an adhesive layer, and a peelable film.

  The adhesive layer is not particularly limited, and examples thereof include anti-inflammatory drugs (for example, ibuprofen, indomethacin, ketoprofen, diclofenac, piroxicam, felbinac, flurbiprofen, loxoprofen, etc. having a carboxyl group (or a salt thereof). Pharmaceutically acceptable salts), menthols (eg i-menthol, etc.), additives such as polyethylene glycol, sodium hydroxide, potassium hydroxide, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, etc. The metal hydroxide and the adhesive component mainly composed of natural or synthetic rubber may be used and may be composed of conventionally known components.

  Also, the release film of the patch of the present invention is not particularly limited, and may be composed of, for example, polyester, polypropylene, polyethylene, paper, or a film or sheet made of a laminate thereof, and conventionally known ones. Can be used. Moreover, in order to improve peeling when the release film is peeled off from the patch, a release film subjected to a release treatment (silicon coating or the like) is also preferably used.

  Next, specific preferred methods for the production method of the crimped yarn of the present invention will be exemplified below.

FIG. 1 is a schematic view of a spinning device preferably used in the present invention. First, polyester constituting the core component is put into the hopper 1, the polyester chip is melted and extruded by the extruder 2, weighed by the gear pump block 5, and the molten polymer is transferred to the spin pack 8 built in the spin block 7. Similarly, the PTT tip put into the hopper 3 is melted and extruded by the extruder 4, weighed by the gear pump block 6, and the molten polymer is transferred to the spin pack 8 built in the spin block 7. After filtering the polymer in the pack, it is bonded to the core-sheath structure with the spinneret 9 and then discharged to obtain the spun yarn 12. The spun yarn is once cooled and solidified by the cooling device 11, then given an oil agent by the oil supply device 13, and properly entangled by the entanglement nozzle 14, and then taken up by the first roll 15 and the second roll 16. The cheese package 18 is obtained by winding with a winder 17. In addition, in order to remove the low melting point substance sublimated from the fiber, a suction device is provided directly under the base. Moreover, in order to suppress the precipitation of monomers and oligomers during spinning and to improve the spinnability, a heating cylinder of 2 to 20 cm under the die and air for preventing oxidative degradation or contamination of the die hole, steam, An inert gas generator such as N ₂ may be installed.

  Subsequently, the film is stretched by a stretching machine and then false twisted, or the unstretched yarn is stretched and false twisted directly by a false twisting machine. A method of false twisting after spin drawing in which spinning and drawing are continuously performed is also preferably used. Here, the multifilament used for false twisting will be referred to as raw yarn. In order to obtain a crimped yarn having higher uniformity and a low degree of irregularity of the single fiber, it is preferable to use an undrawn yarn wound at a high spinning speed or a drawn yarn obtained by spin draw as a raw yarn. Still more preferably, the undrawn yarn or the drawn yarn obtained by spin draw is preferably a raw yarn that has been heat-treated at any stage before winding the raw yarn. In addition, it is also preferable to increase the relaxation rate during winding to increase the uniformity of the raw yarn.

  Here, first, a preferred method for producing a raw yarn before subjecting to false twisting will be specifically exemplified.

  A well-known method can be used for the manufacturing method of the PTT polymer used for this invention. For example, a one-step method in which the degree of polymerization corresponding to the desired intrinsic viscosity is obtained only by melt polymerization, or the degree of polymerization is increased by melt polymerization up to a certain intrinsic viscosity, followed by polymerization corresponding to the desired intrinsic viscosity by solid phase polymerization. The two-step method can be mentioned, but a two-step method combining melt polymerization and solid-phase polymerization is preferable in that a PTT polymer having a low cyclic dimer content is obtained.

  When the PTT polymer obtained by the one-step method is used, it is preferable to reduce the cyclic dimer to 2% by weight or less by an extraction process or the like in any step before being subjected to spinning.

  As the PTT, the higher the intrinsic viscosity of the PTT in the crimped yarn, the easier it is to take advantage of the PTT elastic recovery property. In addition, the higher the intrinsic viscosity of PTT, the higher the heat resistance, and in the manufacturing process, there is a merit that the core component is unevenly distributed in the cross section of the single fiber and the deformation of the cross section in the false twisting process is easily suppressed. As long as it is possible, it is preferable to use a high molecular weight PTT, and it is preferable to use a PTT having an intrinsic viscosity of 0.9 to 2.1 dl / g. More preferably, it is 1.1-1.9 dl / g, More preferably, it is 1.2-1.7 dl / g.

  Further, a PTT polymer having a lower carboxyl end group concentration is preferable because heat resistance at the time of melt storage is increased, and it is preferable to use PTT of 30 eq / ton or less, more preferably 20 eq / ton or less, more preferably 10 eq / ton or less. More preferably.

  Add small amounts of antioxidants and heat stabilizers (hindered phenols, hydroquinones, phosphites and their substitutes, copper halides, iodine compounds, etc.) at any stage to increase the heat resistance of the polymer. It is also preferable.

  In addition, when PET is disposed as the core component, the fluidity at 245 to 280 ° C., which is the optimum melting temperature range of PTT, is good, and the durability is excellent, so that the intrinsic viscosity is 0.41 to 0.61 dl / g. It is preferred to employ a range of low molecular weight PET. More preferably, it is 0.44-0.59 dl / g, More preferably, it is 0.47-0.57 dl / g. In addition, a PET polymer having a lower carboxyl end group concentration is preferable because it can suppress a decrease in molecular weight due to hydrolysis during melt storage, preferably PET of 40 eq / ton or less, more preferably 30 eq / ton or less, More preferably, it is 20 eq / ton or less.

  In addition, for example, when polylactic acid is arranged in the core component, polylactic acid is not so high in heat resistance as PTT, and when melted and stored at a temperature exceeding 265 ° C., polylactic acid undergoes rapid thermal decomposition, If the melt viscosity becomes extremely low and the discharge state becomes unstable, and if it is severe, the spun yarn may bend in the vicinity of the nozzle hole, and the core component of some single fibers may be unevenly distributed. For this reason, in order to increase the melt viscosity of polylactic acid, it is preferable to use high molecular weight polylactic acid, and the weight average molecular weight is preferably 110,000 or more. More preferably, it is 130,000 or more, More preferably, it is 150,000 or more. In addition, it is preferable that the weight average molecular weight is 300,000 or less because abnormal residence in the polymer piping or the spin pack can be suppressed without excessively increasing the melt viscosity in the low shear region. More preferably, it is 280,000 or less, More preferably, it is 260,000 or less. In order to increase the heat resistance of polylactic acid, antioxidants and heat stabilizers (hindered phenols, hydroquinones, phosphites and their substitutes, copper halides, iodine compounds, etc.) can be added at any stage. It is also preferable to add a small amount.

PTT does not have very high heat resistance, and thermal decomposition tends to proceed at temperatures exceeding 280 ° C. On the other hand, at a temperature lower than 245 ° C., the fluidity is poor, and the discharge state may not be stable, or the elongational viscosity may be high, leading to poor thinning. As a result, the spinnability is deteriorated, the fineness CV% of the crimped yarn obtained is deteriorated, and the core component is easily unevenly distributed.
For this reason, it is preferable that the temperature of the PTT flow path (extruder, polymer piping, spin pack, base, etc.) is 245 to 280 ° C. And about the member which can be heated separately from the flow path of a core component, such as an extruder and polymer piping, it is preferable to set it as 250-275 degreeC, and it is more preferable to set it as 255-270 degreeC. On the other hand, for members including a polyester flow path other than polytrimethylene terephthalate, which is a core component, such as a spin pack and a base surface, it is preferable to determine in consideration of fluidity and heat resistance of the core component. Show in detail. The residence time of PTT is preferably 30 minutes or less, more preferably 20 minutes or less, and even more preferably 15 minutes or less. The residence time refers to the residence time from the melting of the polymer to the spinning, which includes the gap between the barrel and screw of the kneader, the specifications of the screw, the piping size between the kneader and the spin pack, the spin pack. It can be estimated from the dimensions inside.

  When the core component is PET, by adopting the low molecular weight PET described above, the temperature of the spinning pack in which the flow paths of both the sheath component and the core component are present can be reduced to 280 ° C. or less. It is preferable because thermal decomposition can be suppressed. Note that the temperature of the spin pack in the present invention is considered to be the same as the temperature of a spin block (an electric heater or a block that heats the spin pack and / or polymer piping with a heating medium). Moreover, since the uneven distribution of the unintended core component can be suppressed by improving the good fluidity of PET, the temperature of the spin pack is preferably 260 ° C. or higher. Therefore, when the core component is made of PET, the temperature of the spinning pack is preferably controlled in the range of 260 to 280 ° C, more preferably 265 to 275 ° C. The temperature fluctuation of the spin pack is preferably suppressed to within ± 3 ° C.

When the core component is polylactic acid, the temperature of the spin pack is preferably 265 ° C. or lower. By setting the temperature of the spinning pack to 265 ° C. or less, it is possible to suppress a decrease in the molecular weight of polylactic acid, which is preferable. On the other hand, in order to lower the melt viscosity of PTT, stabilize the discharge state, and improve the spinnability, it is preferable to set the temperature of the spin pack to 245 ° C. or higher. For this reason, it is preferable that the temperature of a spinning pack shall be 245-265 degreeC, and it is more preferable that it is 250-260 degreeC. Furthermore, it is preferable to keep the temperature fluctuation of the spinning pack within ± 3 ° C. Moreover, it is preferable to suppress thermal decomposition of polylactic acid by shortening the residence time of polylactic acid as much as possible, preferably 30 minutes or less, more preferably 20 minutes or less, and even more preferably 15 minutes or less.
Further, it is preferable that the temperature of the die surface is in the same range as the temperature of the spin block, so that the composite flow of the sheath component and the core component can be stabilized and the uneven distribution of the core component can be suppressed. In the case where the base surface is easily affected by the atmosphere, cooling air, or the like, a method of positively heating the base surface by disposing a contact type or non-contact type heater around the base surface is also preferable. For example, the base heater 10 shown in FIGS. 1, 4 and 7 corresponds to this.

  Further, the crimped yarn of the present invention contains 20 to 40% by weight of polyester other than polytrimethylene terephthalate) as a core component, so that delayed recovery of PTT is suppressed, and the unstretched yarn that is a precursor thereof, or stretched In order to increase the uniformity of the yarn, the result is a crimped yarn having both uniform and bulky properties, but in order to obtain a crimped yarn having higher uniformity and higher bulkiness, the PTT in the base hole It is preferable to reduce the melt viscosity distribution.

  As described above, PTT is a polymer whose melt viscosity is likely to change depending on the shear rate and temperature. In particular, in a region where the shear rate is high and the temperature is low, the melt viscosity tends to change due to slight fluctuations in the shear rate and temperature. Have. In the melt spinning process, if the melt viscosity distribution of the PTT becomes large due to this influence, the sheath component, the core component, and the composite flow in the mouthpiece hole tend to be difficult to form a stable laminar flow. In such a situation, the solidification point of the spinning line may fluctuate and the uniformity of the undrawn yarn may decrease, or the core component may be unevenly distributed as described above.

  In order to avoid such an adverse effect, the area of the discharge hole of the spinneret (hereinafter sometimes simply referred to as the discharge area) is increased to decrease the discharge linear velocity (the polymer flow rate of the final throttle portion of the discharge hole). It is particularly effective to dampen. Further, a method of increasing the discharge hole length, a method of rapidly cooling the spinning wire, and the like are also effective. In addition, the discharge hole length in this invention refers to 19 length in the cross-sectional schematic diagram of a nozzle | cap | die hole shown in FIG. 2, The length of the part by which the hole shape was kept the same shape as the shape of a discharge hole It is a part that controls the flow rate when the polymer is discharged.

The core-sheath composite fiber in the present invention can be obtained by combining a plurality of caps as shown in FIG. 3 and joining the core component and the sheath component at the discharge holes. The discharge linear velocity in the present invention is calculated from the discharge hole area, the total discharge amount, and the number of holes for the three plates immediately before the polymer discharge in FIG.
Discharge linear velocity (m / min) = Q / H / ρ / A / 100
Q: Total discharge rate (g / min)
H: Number of holes ρ: Melt density (g / min)
A: Discharge area (cm ² )

A conventionally known cross-sectional shape of the discharge hole can be used, but the closer the single fiber cross-section of the crimped yarn is to a circular shape, the more preferable, and thus the cross-sectional shape of the discharge hole is preferably a circular shape. In this case, the discharge area is calculated as the area of a circle. The melt density should be calculated as an average value of the melt density of the PTT and the melt density of the core component, and also shows temperature dependence, but in the present invention, it is all PTT and has temperature dependence. It is approximated that there is not, and a melt density of 1.15 g / cm ³ is used.

  Also, the lower the discharge linear velocity, the lower the shear rate applied to the PTT, and the less the fluctuation of the melt viscosity of the PTT, the more stable the composite flow in the discharge holes, which is preferable. On the other hand, it is preferable that the discharge linear velocity is high to some extent, so that the spinning draft is lowered and the spinning property is improved. Therefore, the discharge linear velocity (the polymer flow rate at the final throttle portion of the die hole) is preferably 1 to 15 m / min, more preferably 2 to 14 m / min, and further preferably 3 to 13 m / min. . The discharge linear velocity can be adjusted by appropriately selecting the discharge area of the base final plate, the number of holes, or the total discharge amount.

  The longer the discharge hole length of the base final plate, the more preferable the polymer flow in the discharge hole is in a steady state and the composite flow of the sheath component and the core component is stabilized. On the other hand, if the discharge hole length is too long, the pressure applied to the die surface becomes too high, and running for a long period of time may be difficult. Therefore, the discharge hole length is preferably 0.05 to 2 mm, more preferably 0.1 to 1.9 mm, further preferably 0.15 to 1.8 mm, and 0.2 to 1. 7 mm is particularly preferable.

  In order to rapidly cool the spinning line, a method of reducing the depth of the die surface is preferable. The base surface depth refers to the distance between the cooling start position of the spinning line and the base surface. The shallower the base surface depth (the shorter the distance from the cooling start position and the base surface), the more fine the spinning line is on the upstream side. Completed, that is, the core-sheath composite yarn is solidified in a shorter time, which is preferable because it is easy to suppress the uneven distribution of the core component. However, if the depth of the die surface is too shallow, the die surface temperature becomes too low and the discharge state becomes unstable, and as a result, the uniformity and strength of the fiber may be lowered. Therefore, the depth of the die surface is preferably 0.01 to 0.15 m, and more preferably 0.015 to 0.12 m. More preferably, it is 0.02-0.10 m.

  It is important for the spinning oil agent to prevent contamination of the false twisting heater, prevent slippage with the twisted body (yarn threading property, increase the number of twists on the false twisting heater), and improve fiber migration within the multifilament. For this purpose, it is preferable to use an oil containing a smoothing agent having good heat resistance, a high fiber-twisted friction coefficient, and a low fiber-fiber friction coefficient. For example, a compound obtained by copolymerizing an alkylene oxide having 2 to 4 carbon atoms with an alcohol having one or more hydroxyl groups in the molecule and a compound derived therefrom are preferably used.

  As the alcohol, any natural or synthetic monohydric alcohol having 1 to 30 carbon atoms (methanol, ethanol, isopropanol, butanol, isoamyl alcohol, 2-ethylhexanol, lauryl alcohol, isotridecyl alcohol, isocetyl alcohol, stearyl alcohol) , Isostearyl alcohol, etc.), dihydric alcohols (ethylene glycol, trimethylene glycol, neopentyl glycol, hexylene glycol, etc.) and trihydric or higher alcohols (glycerin, trimethylolpropane, pentaerythritol, sorbitan, sorbitol, etc.) It is done.

  The alkylene oxide having 2 to 4 carbon atoms includes ethylene oxide (hereinafter abbreviated as EO), 1,2-trimethylene oxide (hereinafter abbreviated as PO), 1,2-butylene oxide (hereinafter abbreviated as BO), tetrahydrofuran (hereinafter referred to as THF). And abbreviations). When EO is copolymerized with other alkylene oxide, the ratio of EO needs to be 50 to 80% by weight. If the EO ratio is less than 50% by weight, the viscosity becomes too high, and if it exceeds 80% by weight, the heat resistance becomes poor. The addition mode may be either random addition or block addition. The average molecular weight of the smoothing agent is preferably in the range of 500 to 20,000, more preferably in the range of 1,000 to 10,000 in terms of smoothness and heat resistance.

  The content of these smoothing agents is adjusted to 55% by weight or more based on the whole oil agent, and as other components, ionic surfactants, nonionic surfactants, bundling agents, rust preventives, antiseptics, antioxidants A paste property improver, an antistatic agent, a pH lowering inhibitor, and a water resistance agent may be added as appropriate.

  Moreover, it is preferable that the spinning oil agent is adhered to 0.1 to 3.0% by weight with respect to the whole fiber. The said characteristic is exhibited effectively by making the adhesion amount of an oil agent into 0.1 weight%. On the other hand, when the amount of the oil agent to be adhered exceeds 3% by weight, the false twisting heater, the roll, and the twisted body become very dirty. More preferably, it is 0.2-2.0 weight%, More preferably, it is 0.3-1.0 weight%.

  The oil agent preferably used in the present invention may be adhered straight to the yarn, but in order to adhere more uniformly, it is dispersed as 5 to 50% by weight in water, preferably 5 to 30% by weight, and the fiber is used as an emulsion oil agent. It is preferable to make it adhere to.

  The entanglement nozzle 14 may be installed on the spinning line as shown in FIG. 1, or may be installed between the godet rolls or before the winder. When it is desired to increase the degree of entanglement, it is preferably installed between godet rolls with low yarn tension or before the winder, and when it is desired to reduce the degree of entanglement, it is preferably installed on the spinning line.

  The spinning speed (the peripheral speed of the first roll 15 in FIG. 1) is also an important condition. By increasing the spinning speed, it is possible to make the spun yarn finer on the upstream side, and since it becomes a quenching condition, a more uniform raw yarn can be obtained, which is preferable. In addition, the use of a raw yarn having a high spinning speed is preferable because a crimped yarn having a high bulkiness is obtained. And since the irregularity degree of the single fiber cross section of a crimped yarn becomes small, it is preferable.

  The reason why a crimped yarn having a higher bulkiness than that obtained by high-speed spinning is not clear, but the molecular chain of PTT in the raw yarn is probably highly oriented and has many crystallites. Therefore, it is presumed that orientation crystallization occurs during false twisting and the crimped form is easily fixed. The reason why the cross-section of the single fiber of the crimped yarn can be reduced is that, as described above, the fiber contains many microcrystals, so that the rigidity of the fiber is maintained even under heating and the cross-sectional shape is easily maintained. Estimated. And since many oriented crystal phases are also contained in the crimped yarn after performing the false twisting process, it is presumed that the distortion of the cross section covered by the false twist process is elastically recovered.

  In addition, there is an advantage that interfacial adhesion can be improved as the raw yarn obtained by high speed spinning is used. Although this reason is not certain, it is considered that the difference in the structural strain between the core-sheath components becomes small because the thinning occurs in the high temperature region closer to the base as described above.

Accordingly, the preferred spinning speed is preferably high, 2000 m / min or more, more preferably 2300 m / min or more, and further preferably 2600 m / min or more. On the other hand, considering the process stability in spinning, the spinning speed is preferably 7000 m / min or less. The undrawn yarn obtained at a spinning speed in the above range has an undrawn yarn elongation of 40 to 180%, and the undrawn yarn can be subjected to false twisting as it is. The higher the relaxation rate, the better the adverse effect of delayed recovery of PTT, which is preferable. Here, the relaxation rate is defined by the following equation. The relaxation rate is preferably 3% or more, more preferably 5% or more, and even more preferably 7% or more.
Relaxation rate (%) = {(V ₁ −V ₂ ) / V ₁ } × 100
V ₁ : peripheral speed of the final roll V ₂ : winding speed

  Also, heat treatment is performed at any stage before winding the undrawn yarn, so that the PTT of the original yarn contains more microcrystals, and has higher bulkiness and a single fiber cross-section that is nearly circular. This is preferable because a yarn is obtained. On the other hand, if the heat treatment temperature is too high, the resulting undrawn yarn may become brittle. Therefore, the heat treatment temperature is preferably 50 to 130 ° C, more preferably 60 to 120 ° C, and 70 to More preferably, it is 110 degreeC. Here, the heating source is preferably a contact heating medium such as a heating roll or a heating plate, and the heat treatment temperature refers to the temperature of the heat source. For example, as shown in FIG. 7, it is possible to employ a technique in which a separate roll 40 that provides traverse vibration is installed near the second roll 16 and the spun yarn is passed through the second roll over several turns.

  Of course, a drawn yarn obtained by drawing the undrawn yarn by 1.1 to 3.0 times in a separate step may be used as a raw yarn. At this time, the stretching temperature may be 70 to 100 ° C., and the heat treatment temperature may be 120 to 180 ° C.

  It is also preferable to use a drawn yarn obtained by spin draw as a raw yarn. Here, the spin draw is a method in which the spun yarn is taken up, directly stretched and then wound. That is, it is preferable because drawing can be performed without relaxing the amorphous structure in the spun yarn, so that the molecular chains of the amorphous phase can be easily oriented uniformly, and a raw yarn having a uniform internal structure can be obtained. For example, as shown in FIG. 4, a method of attaching a plurality of heating rolls and stretching at a speed ratio between the heating rolls can be employed. At this time, the stretching may be one stage or multiple stages. In order to improve the uniformity of the drawn yarn obtained by spin draw, it is preferable that the drawing temperature (in FIG. 4, indicates the temperature of the first roll (tandem type) 21) is high. On the other hand, if the stretching temperature is too high, yarn shaking may occur on the heating roll and periodic spots may occur in the longitudinal direction. Therefore, the stretching temperature is preferably 40 to 80 ° C, and 50 to 70 ° C. More preferably. In addition, by performing heat treatment at any stage after drawing and before winding the drawn yarn, the PTT of the original yarn contains more microcrystals, has higher bulkiness, and the single fiber cross section is nearly circular. It is preferable because a crimped yarn is obtained. On the other hand, if the heat treatment temperature is too high, the process passability in false twisting may deteriorate, so the heat treatment temperature is preferably 100 to 200 ° C, more preferably 120 to 180 ° C. 140 to 160 ° C. is more preferable. Here, the heat source for the heat treatment is preferably a heating medium such as a heating roll or a hot plate, and the heat treatment temperature refers to the temperature of the heat source. For example, in the case of FIG. 4, a technique such as heating the second roll (tandem type) 22 can be employed.

  Further, similarly to the case of the undrawn yarn, it is also preferable from the viewpoint of increasing the uniformity of the raw yarn that the relaxation rate is increased. The relaxation rate is preferably 3% or more, more preferably 5% or more, and further preferably 7% or more.

  The winding tension at the time of winding (tension between the final roll and the winder) is preferably 0.04 cN / dtex or more in order to prevent reverse winding, and in order to release the distortion of the fiber internal structure. Is preferably 0.15 cN / dtex or less. A more preferable winding tension is 0.05 to 0.12 cN / dtex, and further preferably 0.06 to 0.1 cN / dtex. Moreover, it is preferable to make the load with respect to the line length which a roller bail or a drive roll is contacting the package (equivalent to the pressure with respect to a package. Hereinafter, it is called a surface pressure) into the range of 6-30 kg / m. By setting the surface pressure to 6 kg / m or more, an appropriate hardness can be given to the package, and package collapse and saddle can be suppressed. Further, by making the surface pressure 30 kg / m or less, the package can be prevented from being crushed or bulged. A more preferable range is 7 to 22 kg / m, and further preferably 8 to 16 kg / m. In addition, by setting the twill angle in the range of 5 to 10 °, it is possible to obtain a stable unwinding tension even at high speed unwinding and to prevent the yarn from collapsing to the end surface while suppressing the yarn dropping on the package end surface. Can do. More preferably, it is 5.5 to 8 °, and further preferably 5.8 to 7 °.

  The drive system at the time of winding is generally driven by a drive roller, but a spindle driving system and a method of forcibly driving a roller bail of the winder are preferably used. When the roller bail is forcibly driven, the roll bail speed relative to the package surface speed is controlled so as to always overfeed 0.05 to 1%, whereby the package foam can be improved.

  Next, a preferred false twisting method will be described with reference to FIG. First, the yarn 26 is pulled out from the cheese package 18 and supplied to the supply roller 29 through the yarn path guides 25 and 27 to 28. Thereafter, the yarn 26 is heat-treated by the first heater 30 while being twisted by a triaxial twister 33 that is a twisted body, and the structure is fixed by a cooling plate 32 through a yarn path guide 31. At this time, the tension measured between the cooling plate 32 and the triaxial twister 33 is the twisting tension (T1), and the tension measured between the triaxial twister 33 and the stretching roller 34 is the untwisting tension (T2). . The structure-fixed yarn 26 is supplied to the second heater 35 through the drawing roller 34, and then wound as a false twisted yarn 39 through the yarn path guides 37 and 38 through the delivery roller 36. In addition, what is necessary is just to put the 2nd heater 35 in the case where low shrinkage is essential according to a use. Moreover, what is necessary is just to arrange | position various guides, tension | tensile_strength control apparatuses, fluid processing apparatuses, oil supply apparatuses, etc. to the apparatus of FIG. 5 as needed.

  It is preferable that the temperature of the 1st heater 30 is the range of 100-160 degreeC in the case of a contact type. When the temperature of the first heater is 100 ° C. or higher, it can be heat-set on the heater, has excellent bulkiness (high CR), and excellent dimensional stability (low boiling water shrinkage). Yarn is obtained. On the other hand, a temperature of 160 ° C. or lower is preferable because the PTT softens on the first heater and the cross section of the single fiber is prevented from being deformed, and the deformed degree of the crimped yarn is reduced. Moreover, since the intensity | strength of a crimped yarn becomes favorable, it is preferable. The temperature of the first heater 30 is more preferably 110 to 150 ° C, and further preferably 120 to 140 ° C.

  Further, it is more preferable that the first heater 30 is a non-contact type because yarn breakage due to abrasion resistance can be suppressed. When a non-contact heater is used for the first heater 30, the heater temperature is preferably 150 to 350 ° C. By setting the temperature of the first heater 30 to 150 ° C. or higher, a crimped yarn having excellent bulkiness (high CR) and excellent dimensional stability (low boiling water shrinkage) can be obtained. On the other hand, a temperature of 350 ° C. or less is preferable because PTT is softened and the cross section of the single fiber is prevented from being deformed, and the deformed degree of the crimped yarn is reduced. Therefore, in the case of the non-contact type, the heater temperature is more preferably 160 to 330 ° C, and further preferably 170 to 300 ° C.

  And it is preferable that the speed ratio of the supply roller 29 and the extending | stretching roller 34 in a false twist process, ie, a process magnification, is 1.1-1.8 times. When the working magnification is 1.1 times or more, the twisting tension (T1) in false twisting is increased, and a high twist number is given to the yarn in the first heater 30, so that the bulky property is excellent (CR is High) crimped yarn. Further, when the processing magnification is 1.8 times or less, the twisting tension (T1) can be suppressed to an appropriate height, the cross section of the single fiber is not easily deformed by the compressive force, and the deformed degree of the crimped yarn is low. Since it becomes small, it is preferable. The processing magnification is more preferably 1.15 to 1.7 times, still more preferably 1.2 to 1.6 times.

  Moreover, since T2 / T1 which is a ratio of untwisting tension (T2) and twisting tension (T1) is 1-2, a crimped yarn is preferably untwisted by a twisted body, which is preferable.

  In particular, in order to obtain a crimped yarn having a low boiling water shrinkage rate, it is preferable to provide the second heater 35 as described above. At this time, the temperature of the second heater 35 is preferably 80 to 150 ° C. The heat shrinkage rate (SW) of the crimped yarn can be controlled by setting the temperature of the second heater and an overfeed rate (hereinafter referred to as OF rate 1) described later. Below 80 ° C., the effect is small. Moreover, it is preferable for the temperature to be 150 ° C. or lower because the crimp developed by the first heater can be maintained, and the bulkiness of the resulting crimped yarn is improved. At the same time, the residual torque can be kept low by optimizing the temperature of the second heater and the OF ratio 1. The temperature of the second heater is more preferably 90 to 140 ° C, and further preferably 95 to 130 ° C.

Further, the OF ratio 1 obtained from the following formula is preferably 10 to 30%.
OF ratio 1 (%) = (V ₃ −V ₄ ) / V ₃ × 100
V ₃ : peripheral speed of stretching roller 34 V ₄ : peripheral speed of delivery roller 36

  If the OF ratio is 10% or more, the boiling water shrinkage of the crimped yarn obtained can be reduced, the dimensional stability can be improved, the residual torque can be reduced, and further the wound crimped yarn Delay recovery can be reduced. On the other hand, if the OF ratio is 30% or less, fusion between single fibers can be prevented, and the running stability of the yarn can be improved. The OF ratio is more preferably 12 to 25%, and further preferably 15 to 20%.

  The ratio of the peripheral speed (D) of the triaxial twister 33 and the speed (Y) of the stretching roller 34 (hereinafter referred to as D / Y) is preferably in the range of 1.1 to 2.0. By setting D / Y to 1.1 or more, the twisting tension and the untwisting tension are well balanced, and false twisting without fuzz and yarn breakage can be performed. Further, by setting D / Y to 2.0 or less, the surface wear of the triaxial twister 33 is suppressed, and there is no unevenness in the longitudinal direction of the yarn even in continuous operation for several hundred hours. Untwisted false twisting is possible. D / Y is more preferably 1.15 to 1.8, and still more preferably 1.2 to 1.7.

  In addition, a belt nip type friction false twisting tool can be preferably used as the triaxial twister 33 for false twisting. The angle formed by doubling the angle between the belt rotation axis that is horizontal in the belt rotation direction and the yarn travel axis that is horizontal in the direction in which the yarn travels is not particularly limited. A range of 90 to 120 ° is preferable because the yarn can be efficiently twisted and the wear of the belt itself can be kept low. Furthermore, although the surface material is not particularly limited, chloropyrene rubber or nitrile butylene rubber can be preferably used. At this time, nitrile butylene rubber is more preferable from the viewpoint of durability, cost, and flexibility. Further, if the surface hardness of the belt nip type friction false twister is 60 to 80 degrees, the cross-sectional deformation of the polylactic acid can be kept low, the scraping of the yarn can be suppressed, and the wear of the belt body is also improved. A range of 65 to 75 degrees is more preferable.

In the method for producing a crimped yarn of the present invention, the overfeed rate (hereinafter referred to as OF rate 2) of the delivery roller 36 is preferably 0 to 35%. More preferably, it is 0 to 25%. The OF ratio is 2 as long as the yarn can be stably wound without the yarn slackening between the delivery roller 36 and the cheese of the false twisted yarn 39, and the yarn tension is 0.02 to 0.10 cN / It is preferable to take up dtex so that the difference between the inner and outer layers of the fiber properties due to tightening can be reduced.
OF ratio 2 (%) = (V ₄ −V ₅ ) / V ₄ × 100
V _4: peripheral velocity _{V 5} of deli Berri roller 36: winding Toshu speed of the cheese

  The crimped yarn obtained by the above method considers process passability in higher-order processes (for example, knitting process), and suppresses abrasion between the fiber and the yarn path guide, knitting needle, etc. as much as possible. It is also preferable to perform additional oil. As the oil to be applied, it is preferable to use an oil containing a smoothing agent having a high effect of reducing the coefficient of friction between the fibers and the metal. For example, fatty acid ester, polyhydric alcohol ester, ether ester, silicone, mineral oil and the like are preferable. These smoothing agents may be used as a single component, but a plurality of components may be mixed and used in consideration of convergence, antistatic properties, and heat resistance. As more preferred smoothing agents, fatty acid esters and mineral oils can be selected. The fatty acid ester is not particularly limited, and examples thereof include monohydric alcohols and monohydric carboxylic acids such as methyl oleate, isopropyl myristate, octyl palmitate, oleyl laurate, oleyl oleate, and isotridecyl stearate. Monohydric alcohols such as esters, dioctyl sebacate, dioleyl adipate, and esters of polyvalent carboxylic acids, polyhydric alcohols such as ethylene glycoldiolate, trimethylolpropane tricaprylate, glycerol trioleate, and monovalents Examples thereof include esters of carboxylic acids and alkylene oxide addition esters such as lauryl (EO) n octanoate. The content of these smoothing agents is adjusted to 55 to 95% by weight based on the whole oil agent, and other components include ionic surfactants, nonionic surfactants, bundling agents, rust preventives, preservatives, and antioxidants. An agent, a penetrating agent, a surface tension reducing agent, a phase inversion viscosity reducing agent, an adhesive property improving agent, an antistatic agent, a pH lowering inhibitor, and a water resistance agent may be added as appropriate.

  Hereinafter, the present invention will be described in detail with reference to examples. In addition, the measuring method in an Example used the following method.

A. Intrinsic viscosity 10 ml of o-chlorophenol (hereinafter abbreviated as OCP) is added to 0.8 g of a sample. And after melt | dissolving at 160 degreeC for 30 minutes, it cooled slowly and the measurement solution was obtained. About this measurement solution, relative viscosity (eta) r was calculated | required by the following Formula using the Ostwald viscometer at 25 degreeC, and intrinsic viscosity was computed.
ηr = η / η ₀ = (t × d) / (t ₀ × d ₀ )
Intrinsic viscosity = 0.0242 ηr + 0.2634
Where η: viscosity of polymer solution, η ₀ : OCP viscosity, t: solution drop time (seconds), d: solution density (g / cm ³ ), t ₀ : OCP drop time (seconds), d ₀ : Density of OCP (g / cm ³ ).

B. Weight average molecular weight of polylactic acid Tetrahydrofuran was mixed with a chloroform solution of a sample (polylactic acid) to obtain a measurement solution. This was measured by gel permeation chromatography (GPC), and the weight average molecular weight was determined in terms of polystyrene. The measurement conditions are as follows.
GPC equipment: Waters2690
Column: Two Shodex GPC K-805L (8mmID * 300mmL) connected together Solvent used: Chloroform (Wako, for HPLC)
Temperature: 40 ° C
Flow rate: 1 ml / min Sample concentration: 10 mg / 4 ml
Filtration: Mysholy disk 0.5μ-TOSOH
Injection volume: 200 μl
Detector: Differential refractometer RI (Waters 2410)
Standard: polystyrene (concentration: sample 0.15 mg / solvent 1 ml)
Measurement time: 40 minutes.

C. Melting | fusing point Melting | fusing point was measured by 2nd run using DSC-7 made from Perkin elmer. At this time, the sample weight was about 10 mg, and the temperature elevation rate was 16 ° C./min.

D. Total carboxyl terminal concentration A precisely weighed sample was dissolved in o-cresol (water content 5%), and an appropriate amount of dichloromethane was added to the solution, followed by titration with a 0.02 N KOH methanol solution. At this time, an oligomer such as lactide, which is a cyclic dimer of lactic acid, is hydrolyzed to generate a carboxyl group terminal, so that all of the carboxyl group terminal of the polymer, the monomer-derived carboxyl group terminal, and the oligomer-derived carboxyl group terminal are totaled. The carboxyl group terminal concentration obtained is obtained.

E. Cyclic Dimer Content 300 mg of the sample was weighed and put into a 100 ml Erlenmeyer flask. Then, 50 ml of hexafluoroisopropanol and 50 ml of chloroform were mixed to prepare a uniform solution, and 10 ml was added to the Erlenmeyer flask. Then, the Erlenmeyer flask was shaken at room temperature for 5 hours to dissolve the sample. Thereafter, 5 ml of chloroform was added and mixed, and further 80 ml of acetonitrile was gradually added. The mixed solution was suction filtered with a glass filter, the filtrate was put into a 200 ml volumetric flask, and acetonitrile was added to make a 200 ml solution. This solution was filtered through a disk filter having a pore size of 0.45 μm to prepare a measurement solution.

About this solution, the HPLC measurement was implemented, the area ( _Ap ) of the peak which belongs to the cyclic dimer in the obtained chromatogram was computed, and content of the cyclic dimer was calculated | required from the following formula.
Cyclic dimer concentration in liquid (mg / l) = 3.63 × 10 ⁻⁵ × A _p
Cyclic dimer content (% by weight) = cyclic dimer concentration in liquid (mg / l) × 0.2 (l) / 300 (mg) × 100

The measurement conditions for HPLC are shown below.
Equipment: Shimadzu LC-10AD (systemml)
Column: Inertsil ODS-3 3.0 × 250 mm
Mobile phase: acetonitrile / water / (70/30)
Flow rate: 0.7 ml / min Detector: 242 nm
Column temperature: 45 ° C
Introduction volume: 5 μl

Here was a regression equation for converting to the concentration of cyclic dimer of A _p in a liquid with the following procedure. That is, a cyclic dimer with a purity of 95% was used as a standard sample, and 10.7 mg of the cyclic dimer was weighed and a constant volume in 25 ml of chloroform was used as a standard stock solution (the concentration of the cyclic dimer with a purity of 100% was 409 μg / ml). Acetonitrile was added to the standard solution to prepare four types of diluted standard solutions having a concentration of 100% purity of the cyclic dimer in the solution of 80 μg / ml, 40 μg / ml, 20 μg / ml, and 10 μg / ml. Each diluted standard solution was subjected to HPLC measurement, and a regression equation was obtained from the relationship between the cyclic dimer concentration in the liquid and the peak area.

F. Deformation degree The crimped yarn was fixed with an embedding material, the section was cut out, deembedded, and then magnified with an optical microscope and photographed. The scale was also photographed at the same magnification. After digitizing the image, using Mitani Shoji's image analysis software “WinROOF, ver5.0”, the diameter D ₁ of the circumscribed circle of the cross section of the single fiber and the inscribed circle of the cross section of the single fiber the diameter _{D 2} was measured. And the irregularity degree of the single fiber was calculated | required by following Formula. And after calculating the irregularity degree of all the single fibers which comprise a multifilament, ten pieces were selected from the big thing, were averaged, and the value which rounded off the 2nd decimal place was made into the irregularity degree.
Modification degree _{= D} 1 _/ D 2.

  The circumscribed circle is defined as a circle having the smallest diameter in a circle that contacts at least two points with the outline of the cross section of the single fiber and includes the cross section of the single fiber. In addition, the inscribed circle is defined as the largest diameter among the circles in contact with the outline of the cross section of the single fiber at at least two points and included in the cross section of the single fiber.

G. Weight fraction of core component (weight ratio)
When melt spinning, the sheath component discharge rate (g / min) and the core component discharge rate (g / min) are measured separately, and the core component discharge rate is determined as the core component discharge rate and the sheath component. The weight fraction of the core component was calculated by dividing by 100 with the sum of the discharge amount and 100 times.

  When measurement in the production process was difficult, the content ratio of the core component was calculated from the area ratio of the cross-sectional photograph of the single fiber of the crimped yarn. That is, the sheath component and the core component of the present invention may contain small amounts of components other than polyester other than PTT and polytrimethylene terephthalate, respectively, but even in this case, the sheath component is substantially PTT and the core component. Can be regarded as consisting of only polyester other than polytrimethylene terephthalate, and the content of the core component can be calculated.

Using the image (cross-sectional photograph, scale) photographed in the section F, Mitani Shoji Co., Ltd. image analysis software “WinROOF, ver5.0”, the sheath component area (A _s ), the core component area ( A _c ) was determined and calculated using the following equation using the specific gravity ρ _{s of the} sheath component and the specific gravity ρ _{c of the} core component.
Content of core component (%) = {(A _c × ρ _c ) / (A _c × ρ _c + A _s × ρ _s )} × 100.

At this time, ρ _s is 1.30, and ρ _c is 1.38 when the core component is made of PET, 1.26 when it is made of polylactic acid, and 1.30 when it is made of other polyesters. It was.

H. Degree of barycentric dissociation Using the image (cross-sectional photograph, scale) taken in the section of F, the barycentric dissociation degree was calculated with image analysis software “WinROOF, ver5.0” of Mitani Corporation. First, the area (A _f ) of the single fiber, the area (A _c ) of the core component, the center of gravity (G _f ) of the single fiber, and the center of gravity (G _c ) of the core component are obtained. The distance (G) between G _f and G _c was measured, and the center of gravity dissociation was determined by dividing G by the diameter D ₁ of the circumscribed circle of the cross section of the single fiber.
Degree of center of gravity dissociation of single fiber = G / D ₁ .

  And after calculating the gravity center dissociation degree about all the single fibers which comprise a multifilament, ten pieces were selected from the largest and averaged, and the thing which rounded off the third decimal place was made into the gravity center dissociation degree.

I. Total fineness and single fiber fineness Measure a 100m crimped yarn in a skein shape with a measuring scale, measure the weight of the 100m crimped yarn, and multiply the weight by 100 to calculate the total fineness (dtex). To do. The measurement was performed three times, and the average value was defined as the total fineness (dtex). Then, the single fiber fineness (dtex) was calculated by dividing the total fineness by the number of filaments.

J. Strength and Elongation According to the constant speed elongation conditions shown in JIS L1013 (Test method for chemical fiber filament yarn, 1998), using Tensilon UCT-100 manufactured by Orientec Co., Ltd., crimped yarn The strength and elongation were measured. At this time, with a sample length of 200 mm and a tensile speed of 200 m / min, the strength is obtained by dividing the strength of the point showing the maximum strength in the SS curve (stress-strain curve) by the total fineness, and the elongation is S- It calculated | required from the elongation of the point which showed the maximum strength in S curve.

K. Modulus of crimped yarn Measure the stress (σ _3% ) when stretched by 3% of the initial length in the SS curve measured in section J, and calculate the modulus of the crimped yarn based on the following formula: did.
Modulus of crimped yarn (cN / dtex) = σ _3% /0.03

L. Tensile elastic recovery rate of crimped yarn The elastic recovery rate of the crimped yarn was measured using Tensilon UCT-100 manufactured by Orientec Co., Ltd. A multifilament crimped yarn was used as a sample, the initial length was 200 mm, the initial load was 0.1 cN / dtex, the tensile speed was 200 mm / min, and the sample was allowed to stand for 1 minute after extending to 10% of the initial length. Thereafter, the chuck is returned at a speed of 200 mm / min to shrink the crimped yarn, and an SS curve is drawn. The elongation when the stress becomes zero during the shrinkage of the crimped yarn is defined as the residual elongation (X). And the elastic recovery factor was calculated | required using the following formula.
Elastic recovery rate of crimped yarn (%) = {(10−X) / 10} × 100

M.M. CR
The crimped yarn was cut off, treated in boiling water for 15 minutes under no load, and then dried in an atmosphere of 25 ° C. and a relative humidity of 65% for 24 hours. The sample was immersed in water under a load equivalent to 0.088 cN / dtex (0.1 gf / d), and the skein length L ₀ after 2 minutes was measured. Then, except for the hank equivalent 0.088cN / dtex in water was replaced with 0.0018cN / dtex (2mgf / d) fine load equivalent was measured skein length _{L 1} after 2 minutes. And CR was calculated by the following formula.
CR (%) = {(L ₀ −L ₁ ) / L ₀ } × 100

N. U%
Using UT4-CX / M manufactured by Zellweger uster, U% (Normal) was measured at a yarn speed of 200 m / min and a measurement time of 1 minute.

O. Fineness CV%
The average value of Af and the standard deviation of Af were calculated using the area (A _f ) of all the single fibers constituting the multifilament obtained in the item of H. The fineness CV% was determined by rounding off the second decimal place of the value obtained by dividing the standard deviation by the average value and multiplying by 100.

P. Boiling water shrinkage rate The crimped yarn was crushed and the initial length (L ₂ ) was measured under a load equivalent to 0.088 cN / dtex. Thereafter, the load was removed, the substrate was treated in boiling water for 15 minutes under no load, and dried under an atmosphere of 25 ° C. and a relative humidity of 65% for 24 hours. The dried casserole was measured for post-treatment length (L ₃ ) under a load corresponding to 0.088 cN / dtex, and the boiling water shrinkage was measured by the following equation.
Boiling water shrinkage (%) = {(L ₂ −L ₃ ) / L ₂ )} × 100

Q. Residual torque The upper ends of both ends are 0.059 cN / dtex so that the crimped yarn is bent into a V shape with a ceramic rod guide as a fulcrum so that no untwisting and untwisting occur. Fix under load of. A fine load of 0.003 cN / dtex is applied to the sample portion of the rod guide, the sample is removed from the rod guide, and the sample is self-rotated in a suspended state. When the turning stopped, the twisting was carried out with a twisting machine and the number of turns was measured. The residual torque per 1 m of sample was calculated | required by making the test frequency into 5 times and doubling the average value.

R. Content of spiral crimp The crimped yarn was cut at random locations, and 50 mm long crimped yarn was collected. The crimped yarn was split and separated into single fibers, and the crimped form was observed with a microscope (Keyence Corporation, digital microscope, model VHX-100) at an observation magnification of 400 times. Then, the number (Z) of single fibers having spiral crimps as shown in FIG. 6 is counted, and a value obtained by dividing Z by the number of filaments and multiplying by 100 is defined as the content of spiral crimps. And it measured 5 times and made the average value the content rate of spiral crimp.

  At this time, when spiral crimps having a pitch of 10 μm to 5 mm and an amplitude of 30 μm to 3 mm were continuously formed with a length of 10 mm or more, they were counted as single fibers having spiral crimps.

S. Strength of crimped yarn after hydrothermal treatment (hydrolysis resistance)
The crimped yarn cut with a measuring instrument was treated in a constant temperature and humidity chamber (manufactured by Nagano Scientific Machinery Co., Ltd., model LH-20-11M) at a bath temperature of 70 ° C. and a relative humidity of 95% for 7 days. Thereafter, a crimped yarn dried for 24 hours in an atmosphere of 25 ° C. and a relative humidity of 65% was used as a sample. And based on the method of the term of J, the intensity | strength of this sample was measured 5 times, and let the average value be the intensity | strength of the crimped yarn after wet heat processing.

T.A. Modulus of knitted fabric A double-sided smooth knitted fabric was knitted with an interlock structure using a crimped yarn and a 28-gauge circular knitting machine. This knitted fabric was subjected to scouring, dyeing, and reduction washing with a drum dyeing machine (model RD-300AT, manufactured by Tecsum Giken Co., Ltd.), and after washing with water and dehydration, it was opened and dried. The dried knitted fabric was heat set at 150 ° C. for 1 minute to obtain a 43-well, 40-course knitted fabric. The staining conditions are shown below.

(1) Refining An aqueous solution of sodium carbonate 1 g / L, Sunmol RC-700 (trademark, manufactured by Nikka Chemical Co., Ltd.) 0.2 g / L is prepared, and the liquid temperature is 70 ° C. for 20 minutes at a temperature rising rate of 3 ° C./minute. , Refined. At this time, the bath ratio (weight ratio between the knitted fabric and the aqueous solution) was 1:20.

(2) Dyeing Dianix Blue AC-E (trademark, manufactured by Dystar) 0.3% owf as a disperse dye, Nikkasan Salt 7000 (trademark, manufactured by Nikka Chemical Co., Ltd.) as a dispersant, and acetic acid / sodium acetate as a pH adjuster The pH was adjusted to 5. The temperature was raised to 120 ° C. at a rate of temperature increase of 3 ° C./min, dyed for 45 minutes after reaching the liquid temperature of 120 ° C., cooled to 60 ° C. and taken out. At this time, the bath ratio (weight ratio between the knitted fabric and the dyeing solution) was 1:20.

(3) Reductive cleaning An aqueous solution of sodium hydroxide 0.5 g / L, hydrosulfite 2 g / L, and Sunmol RC-700 0.2 g / L was prepared, and the bath temperature (80 ° C., 20 minutes, Reduction washing was performed at a weight ratio of knitted fabric and aqueous solution of 1:20.

  The obtained knitted fabric was cut out with a width of 25 mm in each of the vertical and horizontal directions, and used as a measurement sample.

  The modulus of the sample was measured using TENSILON UCT-100 manufactured by Orientec Co., Ltd. At this time, the sample width was 25 mm, the initial length was 50 mm, the initial load was 5 cN, the tensile speed was 50 mm / min, and the load at the time of elongation to 50% of the initial length was measured to obtain a modulus. The measurement was performed 5 times and averaged.

U. 50% elongation elastic recovery rate of knitted fabric The knitted fabric after dyeing obtained in the section of T was cut out in a 25 mm width in the vertical direction and the horizontal direction, and used as a measurement sample. A 50% stretch elastic recovery rate of the sample was measured using Tensilon UCT-100 manufactured by Orientec Co., Ltd. At this time, the sample width was 25 mm, the initial length was 50 mm, the initial load was 5 cN, and the tensile speed was 50 mm / min. After extending to 50% of the initial length, the sample was left for 1 minute. Thereafter, the chuck was returned at a speed of 50 mm / min to shrink the sample, and a load-elongation curve was drawn. The elongation when the load becomes zero during contraction of the sample is defined as the residual elongation (Y). And the 50% elongation elastic recovery rate was calculated | required using the following formula.
50% elastic recovery rate of knitted fabric (%) = {(10−Y) / 10} × 100

V. Leveling property of the knitted fabric Using the knitted fabric after dyeing obtained in the section T, the leveling property of the knitted fabric was evaluated by five panelists. And comprehensive evaluation was decided by the total score of each person's evaluation.

<Evaluation criteria>
5 points: no staining spots 4 points: almost no staining spots 3 points: some staining spots are seen 2 points: staining spots are seen 1 points: staining spots are seen on the entire knitted fabric
<Comprehensive evaluation>
Double circle (excellent): 21 to 25 points ○ (good): 16 to 20 points Δ (possible): 11 to 15 points × (inferior): 5 to 10 points.

W. Knitted Fabric Tactile Feel Using the dyed knitted fabric obtained in the section T, the tactile feel of the knitted fabric was evaluated by five panelists. And comprehensive evaluation was decided by the total score of each person's evaluation.

<Evaluation criteria>
5 points: Soft touch and extremely smooth surface.
4 points: Soft touch and relatively smooth surface.
3 points: Standard softness and slightly rough surface.
2 points: Somewhat rough and hard on the surface.
1 point: There is a feeling of coarseness and the roughness of the surface is severe.

<Comprehensive evaluation>
Double circle (excellent): 21 to 25 points ○ (good): 16 to 20 points Δ (possible): 11 to 15 points × (inferior): 5 to 10 points.

X. Wearing feeling of the patch The dyed knitted fabric obtained in the section T is cut into a square of 100 mm in length and 100 mm in width (cut out so as to match the warp and width direction of the knitted fabric), and a rubber-based surface on one side A patch sample was prepared by applying an adhesive. And it affixed on the test subject in the state which extended the elbow so that the horizontal direction of a knitted fabric (the horizontal direction of a sample) might become a longitudinal direction of an arm to a test subject. Five subjects gave elbow flexion / extension movement 100 times, and evaluated the feeling of patch stickiness, skin irritation, and peeling. Moreover, it stuck on five test subjects similarly in the state which bent the elbow, and the wrinkle generation state of the state which extended the elbow was evaluated. Five subjects evaluated the above four items, and a comprehensive evaluation was determined.

<Evaluation criteria>
5 points: No tension, no irritation to the skin, no peeling and no wrinkles.
4 points: There is one item that is slightly insufficient among the sense of tension, irritation to the skin, peeling, and wrinkles.
3 points: There are two or more items that are slightly insufficient among the sense of tension, skin irritation, peeling, and wrinkles.
Two points: There is one item that is clearly insufficient among the sense of tension, irritation to the skin, peeling, and wrinkles.
1 point: There are two or more items that are clearly insufficient among the sense of tension, skin irritation, peeling, and wrinkles.

<Comprehensive evaluation>
Double circle (excellent): 21 to 25 points ○ (good): 16 to 20 points Δ (possible): 11 to 15 points × (inferior): 5 to 10 points.

Y. Evaluation of yarn-making property In obtaining 98 kg crimped yarn, the yarn-making property was evaluated by the total number of yarn breaks that occurred (the total number of yarn breaks that occurred in the spinning step, drawing step, and false twisting step). Evaluation was made in four stages: excellent (double circle), good (◯), acceptable (Δ), and impossible (×).
Double circle: No thread break ○: 1 to 10 thread breaks Δ: 11 to 20 thread breaks X: 21 or more thread breaks

Z. The knitted fabric after dyeing obtained in the section of the basis weight T was cut into a square having a length of 100 mm and a width of 100 mm, the weight was measured, and the basis weight (g / m ² ) was obtained by multiplying by 100.

AA. The dyed knitted fabric obtained in the section of well, course T is cut into a square of 100 mm in length and 100 mm in width, and observed with a microscope (Keyence Corporation, digital microscope, model VHX-100) at a magnification of 400 times. Observed and counted knitting wells and courses.

AB. Melting point, Tg
The melting point of the polymer was measured at 2nd run using DSC-7 manufactured by Perkin elmer. The endothermic peak at the highest temperature was taken as the melting peak, and the temperature giving the extreme value of the melting peak was taken as the melting point (° C.). Tg was determined from the inflection point of the suggested heat quantity curve. The measurement conditions were a sample weight of about 10 mg and a heating rate of 16 ° C./min.

AC. Lactide amount 1 g of sample is dissolved in 20 ml of dichloromethane, and 5 ml of acetone is added to this solution. Furthermore, it was made to deposit with cyclohexane, it was made to precipitate, it analyzed by the liquid chromatograph using Shimadzu GC17A, and the amount of lactide was calculated | required with the absolute calibration curve.

[Production Example 1] (Production of polylactic acid (PLA1))
Polymerization of lactide produced from L-lactic acid with an optical purity of 99.5% in the presence of bis (2-ethylhexanoate) tin catalyst (lactide to catalyst molar ratio = 10000: 1) at 180 ° C. for 160 minutes in a nitrogen atmosphere To obtain polylactic acid (PLA1). The obtained PLA2 had a weight average molecular weight of 160,000. The amount of residual lactide was 0.10% by weight. PLA2 had a Tg of 58 ° C. and a melting point of 170 ° C.

[Production Example 2] (Production of polylactic acid (PLA2))
Polymerization of lactide produced from L-lactic acid with an optical purity of 99.5% in the presence of bis (2-ethylhexanoate) tin catalyst (lactide to catalyst molar ratio = 10000: 1) at 180 ° C. for 220 minutes in a nitrogen atmosphere To obtain polylactic acid (PLA2). The obtained PLA1 had a weight average molecular weight of 210,000. The amount of lactide remaining was 0.13% by weight. PLA1 had a Tg of 58 ° C. and a melting point of 170 ° C.

(Example 1)
Intrinsic viscosity of 1.5 g / dl, Tg of 48 ° C., melting point of 230 ° C., cyclic dimer content of 2.6 wt%, carboxyl end group concentration of 12 eq / ton, and average secondary particle diameter of 0.4 μm are 0. PTT containing 3 wt% was used as a sheath component, and PET having an intrinsic viscosity of 0.5 g / dl, Tg of 70 ° C., a melting point of 254 ° C., and a carboxyl end group concentration of 25 eq / ton was used as a core component. Each was vacuum-dried at 150 ° C. for 10 hours, and the water content was adjusted to 50 ppm or less.

  Then, using the spinning machine shown in FIG. 1, the sheath component was introduced into the hopper 1, heated and melted by the extruder 2, measured by the gear pump 5, and led to the spinning pack 8. A core component was charged into the hopper 3, heated and melted by the extruder 4, weighed by the gear pump 6, and led to the spinning pack 8. Then, the sheath component and the core component were joined at the base 9 disposed inside the base to obtain a spun yarn. At this time, as the base 9, a base formed by combining three pieces as shown in FIG. Cooled and solidified by blowing cooling air to the spun yarn by the cooling device 11, and an oil agent was applied while concentrating the spun yarn by the oil supply device 13 at a position 2 m below the base, and the working nozzle 14 was operated with compressed air pressure 0 Was entangled at 2 MPa, taken up by the first roll 15 and the second roll 16, and wound with an undrawn yarn made of core-sheath composite fiber of 73 dtex and 40 filaments. At this time, the winding speed was adjusted so that the winding tension was constant, and the drum was replaced every 5 kg, and 20 5-kg packages (100 kg in total) were produced. No yarn breakage occurred during spinning, and the yarn-making property was extremely excellent. And the cross section of the single fiber of the obtained undrawn yarn was circular.

  Using the undrawn yarn as a raw yarn, a false twisted yarn was obtained using the false twist processing machine shown in FIG. The cheese package 18 is set, the yarn 26 is pulled out, and is supplied to the supply roller 29 via the yarn path guides 25 and 27 to 28. Thereafter, the yarn 26 is heat-treated by the first heater 30 while being twisted by the triaxial twister 33, and the structure is fixed by the cooling plate 32 through the yarn path guide 31. At this time, the tension is measured between the cooling plate 32 and the triaxial twister 33 to obtain the twisting tension (T1), and the tension is measured between the triaxial twister 33 and the stretching roller 34, and the untwisting tension (T2). It was. The structure-fixed yarn 26 is wound up as a false twisted yarn 39 via a drawing roller 34 and then via a delivery roller 36 via yarn path guides 37 and 38. The second heater 35 was not used. A crimped yarn of 56 dtex, 40 filaments was obtained by applying the false twisting process. Twenty 4.9 kg wound packages (a total of 98 kg) were produced, but yarn breakage did not occur during false twisting, and the yarn forming property was extremely good.

The spinning conditions are described below.
・ Extruder temperature of sheath component: 260 ℃
・ Extruder temperature of core component: 285 ℃
Spin block temperature: 270 ° C
-Weight fraction of core component: 30% by weight
Filter layer: Both sheath component and core component are filled with 30 g Morundan sand, 200 g. Filter: Both sheath component and core component are 20 μm non-woven filter. Plate 3 of the base (plate 3 in the schematic diagram of FIG. 3). The base where the sheath component and the core component merge): discharge hole diameter 0.26 mm, discharge hole length 0.5 mm, number of holes 40
・ Discharge rate: 20.9 g / min (1 pack 1 yarn, 40 filaments)
・ Cooling air: Uniflow with a cooling length of 1 m is used. Cooling air temperature 20 ° C, wind speed 0.5m / sec, base depth: 0.08m
・ Base heater temperature: 280 ℃
・ Base temperature: 267 ℃
・ Oil agent: For spinning oil, 70% by weight of polyether having a weight average molecular weight of 2000 as a smoothing agent, 8% by weight of polyether having a weight average molecular weight of 6000, 12% by weight of ether ester, other additives (antistatic agent, (Oxidizing agent, rust preventive agent) was adjusted to 10% by weight, and this oil was adjusted as a water emulsion to a concentration of 10% by weight, and about 0.8% by weight was adhered to the fiber as a pure oil component.
・ First roll speed: 3000 m / min ・ Second roll speed: 3000 m / min ・ First roll temperature: 25 ° C.
-Second roll temperature: 25 ° C
-Winding speed: 2970 m / min-Relaxation rate: 1%
The false twisting conditions are described below.
Feed roller speed: 370 m / min Stretch roller speed: 500 m / min First heater temperature: 130 ° C.
-False twisting magnification: 1.30
DY ratio: 1.35
・ T2 / T1: 1.3
・ Delivery roller speed: 480 m / min ・ Winding speed: 466 m / min ・ OF ratio 1: 4%
・ OF ratio 2: 3%

  When the cross section of the single fiber of the crimped yarn obtained was observed, the substantially circular shape was maintained and the degree of deformity was 1.1. The modulus of the crimped yarn of Example 1 was 30 cN / dtex, the elastic recovery rate was 92%, and it was a crimped yarn excellent in recoverability after removing the stress while expanding and contracting with a low force. Further, CR was 50%, which was extremely excellent in bulkiness, and U% (normal) was 0.8, which was excellent in the uniformity of the multifilament in the longitudinal direction. The fineness CV% was 2%, and the crimped yarn had a uniform thickness between single fibers. The crimped yarn had a strength of 2.8 cN / dtex, an elongation of 40%, a boiling water shrinkage of 11%, and a residual torque of 118 T / m. The cyclic dimer content was 1.8% by weight, and the total carboxyl end group concentration was 22.7 eq / ton. The strength of the crimped yarn after the wet heat treatment was as high as 2.6 cN / dtex, and the crimped yarn was excellent in hydrolysis resistance. The degree of dissociation of the center of gravity in the cross section of the single fiber was 0, and it was a crimped yarn not including a single fiber having spiral crimps.

  Using the crimped yarn of Example 1, a dyed knitted fabric was obtained based on the method described in the section T. The knitted fabric was a knitted fabric having a low modulus and a high elastic recovery rate in both the vertical and horizontal directions, and had soft stretch properties. Moreover, there was no dyeing spot over the entire knitted fabric, and it was a knitted fabric excellent in levelness. Moreover, it was a high-grade knitted fabric with a soft touch that was full of luxury and had no surface roughness.

  Using the obtained knitted fabric, a patch was prepared based on the method described in the section X. The patch was an excellent patch with no tension or irritation to the skin even after bending and stretching exercises. Further, it did not peel off or wrinkle, and had excellent characteristics as a patch.

  Since the crimped yarn and the knitted fabric of Example 1 have excellent characteristics as described above, they were also used for clothing and industrial use. The results of Example 1 are shown in Table 1.

(Examples 2-3 and Comparative Examples 1-3)
In Example 1, a crimped yarn of 56 dtex and 40 filaments was obtained in the same manner as in Example 1 except that the weight fraction of the core component was changed by changing the discharge amount of the sheath component and the core component. . A knitted fabric and a patch were prepared and evaluated.

  In Examples 2 to 3, yarn breakage, fluff and the like did not occur in the spinning and false twisting steps, and the yarn forming property was excellent.

On the other hand, in Comparative Examples 1 and 2, thinning of the spun yarn during spinning was not stable, and in 100 kg spinning, yarn breakage occurred 15 times and 8 times, respectively. Furthermore, when false twisting a 100 kg raw yarn, the yarn breakage occurred 14 times and 9 times, respectively, and the yarn forming property was extremely poor. The undrawn yarn package and the crimped yarn package were wound by the delayed recovery of PTT, the package was cured, and the wound foam was bad. The weight fractions of the core components of Examples 2-3 and Comparative Examples 1-3 are shown below, and the results of Examples 2-3 and Comparative Examples 1-3 are shown in Table 1.
Example 2: Weight fraction of core component 20% by weight
Example 3: Weight fraction of core component 40% by weight
Comparative Example 1: Core component weight fraction 0% by weight
Comparative Example 2: Core component weight fraction 10% by weight
Comparative Example 3: Weight fraction of core component 50% by weight

  As can be seen from a comparison between Example 2 and Comparative Examples 1 and 2, by using a crimped yarn containing a weight fraction of the core component of 20% by weight or more, the modulus is low and the elastic recovery rate is high. It can be seen that a crimped yarn having excellent uniformity can be obtained due to the effect of suppressing delayed recovery. As a result, it is understood that the knitted fabric made of crimped yarn has excellent levelness and feel, and even when it is used as a patch, it is an excellent patch with no tension or irritation to the skin. In addition, peeling and wrinkles do not occur, and it can be seen that satisfactory characteristics are expressed as a patch.

  Comparative Examples 1 and 2 are crimped yarns having a low modulus and a high elastic recovery rate. However, since the fineness CV% is particularly large, streaks are severe in the knitted fabric after dyeing, and stepwise dyeing differences in the knitting direction. It was what had. Further, the surface of the knitted fabric has a large roughness, and when used as a patch, the skin is strongly stimulated during bending and stretching movements and cannot be practically used.

  Further, as can be seen from a comparison between Example 3 and Comparative Example 3, by making the weight fraction of the core component 40% by weight or less, it is uniform without killing the characteristics of PTT having a low modulus and a high elastic modulus. It turns out that it becomes a crimped yarn excellent in the property and the bulkiness. When the core component is 40% by weight, the crimped yarn has excellent hydrolysis resistance and the crimped yarn has excellent durability. In addition, by containing a large amount of PTT with a low weight fraction of the core component, that is, excellent in elastic recovery, it is possible to suppress deformation of the cross section in the false twisting process and to reduce the degree of deformation of the crimped yarn. I understand. Moreover, it turns out that the thickness spot of a single fiber can also be made small by suppressing the deformation | transformation of a cross section.

  The crimped yarn of Comparative Example 3 has a high modulus and low elastic recovery, which is also reflected in the stretch properties of the knitted fabric. When used as a patch, there is a feeling of following the bending and stretching movements. Peeling and wrinkles occurred and the feeling of wearing was bad. In addition, due to the large degree of deformation of the crimped yarn, an apparent roughness was generated on the surface of the knitted fabric. And the fineness CV% of the crimped yarn was large and the uniformity was low, so that clear streaks were scattered on the knitted fabric, and the quality was low.

  As can be seen by comparing Examples 1 to 3, by making the weight fraction of the core component a more preferable range in the present invention, the uniformity of the crimped yarn, the bulkiness, and the hydrolysis resistance are excellent in a good balance. It turns out that it becomes a crimped yarn and becomes a better knitted fabric and a patch.

(Examples 4-5, Comparative Examples 4-5)
In Example 3, in Example 4 and Comparative Example 4, the temperature of the first heater during false twisting is used. In Example 5 and Comparative Example 5, in the spinning process, the base plate 3, discharge amount, spinning speed, winding A crimped yarn of 56 dtex and 40 filaments was obtained in the same manner as in Example 3 except that the take-up speed was changed and the speed of the supply roller was changed in the false twisting process. Although it was not a problem level in Example 4, yarn breakage occurred 3 times / 100 kg in the false twisting process. In Example 5, yarn breakage did not occur in each step, and the yarn making property was excellent. On the other hand, in each of Comparative Examples 4 to 5, fluff frequently occurred in the false twisting process, yarn breakage of 13 times / 100 kg occurred, and the process passability was poor. The conditions changed from Example 3 in Examples 4 to 5 and Comparative Examples 4 to 5 are shown below. Table 2 shows the results of Examples 4 to 5 and Comparative Examples 4 to 5.

Example 4
First heater temperature: 150 ° C
Comparative example 4
First heater temperature: 170 ° C
Example 5
Base plate 3: discharge hole diameter 0.28 mm, discharge hole length 0.5 mm, number of holes 40
Discharge amount: 24.8 g / min First roll speed: 4000 m / min Second roll speed: 4000 m / min Winding speed: 3960 m / min Yarn feeding roller speed: 417 m / min False twisting ratio: 1.20
Comparative example 5
Base plate 3: discharge hole diameter 0.24 mm, discharge hole length 0.5 mm, number of holes 40
Discharge rate: 17.7 g / min First roll speed: 1800 m / min Second roll speed: 1800 m / min Winding speed: 1782 m / min Yarn feeding roller speed: 263 m / min False twisting magnification: 1.90

  As can be seen by comparing Examples 3 to 5 and Comparative Examples 4 to 5, the deformation of the cross section in the false twisting process is suppressed, and the deformed degree of the crimped yarn of the present invention is set to 1.5 or less, so that it becomes more uniform. It can be seen that the knitted fabric has excellent dyeability. And as can be seen from Examples 3 to 5, by adopting a preferred production method (first heater temperature, spinning speed) in the present invention, a crimped yarn with a smaller degree of irregularity is obtained, the surface is smooth, It can be seen that a knitted fabric without roughness can be obtained. At the same time, the thickness variation of the single fiber is reduced, and the knitted fabric is excellent in leveling. In the knitted fabrics of Comparative Examples 4 and 5, clear streaky stained spots were observed, the appearance quality was inferior, and the knitted fabric was inferior in surface quality as compared with the Examples. The patch obtained from the knitted fabric had a strong irritation and inferior wearing feeling when bending and stretching.

(Examples 6 to 9)
In Example 1, 56 dtex, 40 filaments were used in the same manner as in Example 1 except that the spinning plate 3 and the discharge amount were changed and the speed of the yarn supplying roller was changed to change the false twisting magnification. Of crimped yarn was obtained. A knitted fabric and a patch were prepared and evaluated. In Example 8, although not at a problematic level, yarn breakage occurred once / 100 kg in the false twisting process. In Examples 6, 7, and 9, yarn breakage did not occur in each step, and the yarn making property was excellent. In Examples 6 to 9, the conditions changed from Example 1 are shown below. The results of Examples 6 to 9 are shown in Table 3.

Example 6
Base plate 3: discharge hole diameter 0.25 mm, discharge hole length 0.5 mm, number of holes 40
Discharge rate: 19.4 g / min Yarn feeding roller speed: 400 m / min False twisting magnification: 1.25
-Example 7
Base plate 3: discharge hole diameter 0.27 mm, discharge hole length 0.55 mm, number of holes 40
Discharge amount: 21.7 g / min Yarn feeding roller speed: 357 m / min False twisting magnification: 1.4
Example 8
Base plate 3: discharge hole diameter 0.28 mm, discharge hole length 0.6 mm, number of holes 40
Discharge amount: 23.2 g / min Yarn feeding roller speed: 333 m / min False twisting magnification: 1.5
Example 9
Base plate 3: discharge hole diameter 0.25 mm, discharge hole length 0.5 mm, number of holes 40
Discharge rate: 18.6 g / min Yarn feeding roller speed: 417 m / min False twisting magnification: 1.2

  As can be seen from a comparison between Example 1 and Examples 6 to 9, the crimped yarn of the present invention has no bulkiness between single fibers as a crimped yarn rich in bulky properties, and has excellent knitted fabric and sticking It turned out to be an agent. And by using a crimped yarn having a CR of 40% or more, which is preferable in the present invention, it becomes a knitted fabric with a lower modulus and a higher elastic recovery rate, and when it is used as a patch, there is no skin tension, It can be seen that even in repeated bending and stretching movements, it peels off and becomes excellent without wrinkles.

  In addition, by using a crimped yarn having a CR of 60% or less, the crimped yarn has excellent mechanical properties, and the strength after wet heat treatment is increased. It turns out that a ground and a patch are obtained. In addition, since the crimped yarn has a small cross-sectional deformation and a high uniformity in the false twisting process, it can be seen that the leveling property is more excellent.

  Therefore, when the CR of the crimped yarn is 40 to 60%, the crimped yarn further has low modulus, bulkiness, uniformity, mechanical properties, and hydrolysis resistance, and the crimped yarn The knitted fabric made of the present invention was more excellent in levelness, feel and wearing feeling when used as a patch.

(Examples 10 to 13)
In Example 1, a 56 dtex crimped yarn of Examples 10 to 13 was used in the same manner as in Example 1 except that a base having a different discharge hole specification and number of filaments was used and the number of filaments of the obtained crimped yarn was changed. Got. A knitted fabric and a patch were prepared and evaluated. In Examples 10 and 11, the yarn breakage occurred once / 100 kg in each of the spinning process and false twisting process, although this was not a problem level. In Examples 12 and 13, yarn breakage did not occur in each step, and the yarn forming property was excellent. In Examples 10 to 13, the conditions changed from Example 1 are shown below. The results of Examples 10 to 13 are shown in Table 4.
Base plate 3 of Example 10: discharge hole diameter 0.19 mm, discharge hole length 0.4 mm, number of holes 72
Base plate 3 of Example 11: discharge hole diameter 0.14 mm, discharge hole length 0.3 mm, number of holes 144
Base plate 3 of Example 12: discharge hole diameter 0.29 mm, discharge hole length 0.6 mm, number of holes 32
Base plate 3 of Example 13: discharge hole diameter 0.37 mm, discharge hole length 0.8 mm, number of holes 20

  In addition, about the plates 1 and 2 of the nozzle | cap | die of Examples 10-13, the number of holes was changed according to the number of filaments.

  As can be seen by comparing Example 1 and Examples 10 to 13, since the crimped yarn of the present invention is a core-sheath composite fiber containing a specific core component, it is a fine denier crimped yarn having a small single fiber fineness. It can also be seen that the fiber uniformity is excellent. It can be seen that a crimped yarn having a good bulkiness can be obtained from the characteristic of PTT having excellent elasticity. For this reason, a knitted fabric with a high-quality and soft touch feeling can be obtained by peach touch, and a patch excellent in wearing feeling can be obtained without any irritation to the skin.

  On the other hand, since the single fiber fineness is somewhat thick, a knitted fabric that is difficult to crimp and has excellent bulkiness and elastic recovery is obtained. It can also be seen that the crimped yarn is excellent in practical durability because the mechanical properties and hydrolysis resistance of the crimped yarn are increased. That is, a crimped yarn having a single fiber fineness within a range preferred in the present invention is a crimped yarn having a good balance in terms of low modulus, bulkiness, uniformity, mechanical properties, and hydrolysis resistance, The crimped yarn was excellent in leveling and touch feeling of the knitted fabric, and was excellent in wearing feeling when used as a patch.

(Example 14, Comparative Examples 6-8)
In Example 3, a crimped yarn of 56 dtex, 40 filaments of Example 14 and Comparative Example 6 was obtained in the same manner as Example 3 except that the specifications of the discharge holes were changed. In Example 3, a 56 dtex, 40 filament crimped yarn of Comparative Examples 7 to 8 was obtained in the same manner as in Example 3 except that the spin block temperature was changed. Then, a knitted fabric and a patch were prepared and evaluated using each.

In Example 14, although not at a problematic level, yarn breakage occurred once / 100 kg in each of the spinning process and the false twisting process. In Comparative Example 6, yarn breakage occurred 7 times / 100 kg in the spinning process, and yarn breakage occurred 7 times in the false twisting process, and Example 3 was superior in yarn production. In Comparative Example 7, yarn breakage occurred 8 times / 100 kg in the spinning process, and yarn breakage occurred 3 times in the false twisting process, and Example 3 was superior in yarn production. In Comparative Example 8, yarn breakage occurred 6 times in the spinning process, and yarn breakage occurred 6 times in the false twisting process. Therefore, Example 3 was superior in yarn production. The conditions changed from Example 3 in each are shown below. The results of Example 14 and Comparative Examples 6 to 8 are shown in Table 5.
Base plate 3 of Example 14: discharge hole diameter 0.20 mm, discharge hole length 0.4 mm, number of holes 40
Base plate 3 of Comparative Example 6: discharge hole diameter 0.19 mm, discharge hole length 0.4 mm, number of holes 40
Spin block temperature of Comparative Example 7: 290 ° C
Spin block temperature of Comparative Example 8: 255 ° C.

  As can be seen from a comparison between Examples 3 and 14 and Comparative Examples 6 to 8, the core component is unevenly distributed in the spinning process for the first time by adopting a preferable production method (discharge linear velocity, spin block temperature) in the present invention. It can be seen that is suppressed. A crimped yarn with a lower center-of-gravity dissociation does not contain a single fiber with spiral crimps, so the surface of the knitted fabric is smoother and smoother, and has better wearing feeling when used as a patch. It becomes. Since the uneven distribution of the core component is suppressed at the raw yarn stage, the cross-sectional deformation of the single fiber in the false twisting process can be suppressed, and a crimped yarn having a small degree of deformation and excellent uniformity can be obtained.

(Example 15)
In Example 1, the second heater 35 was used at the time of false twisting, and 56 dtex, 40 filaments were obtained in the same manner as in Example 1 except that the false twisting conditions, the base plate 3 in melt spinning, and the discharge amount were changed. A crimped yarn was obtained. A knitted fabric and a patch were prepared and evaluated. In Example 15, yarn breakage did not occur in each step, and the yarn forming property was excellent. The conditions changed from Example 1 are shown below. The results of Example 15 are shown in Table 6.

Example 15
Base plate 3: discharge hole diameter 0.24 mm, discharge hole length 0.5 mm, number of holes 40
Discharge rate: 17.7 g / min Second heater temperature: 100 ° C.
Delivery roller speed: 400 m / min Winding speed: 392 m / min OF ratio 1: 20%
OF ratio 2: 2%

  The crimped yarn of Example 15 was a crimped yarn having a boiling water shrinkage rate as low as 6.2% and a residual torque as low as 53 T / m as compared with Example 1. And it was a crimped yarn with good bulkiness, low modulus and high elastic recovery, excellent mechanical properties, hydrolysis resistance and uniformity. For this reason, the resulting knitted fabric was excellent in levelness and feel, and was excellent in wearing comfort of the patch.

(Examples 16 to 17)
In Example 3, a crimped yarn was obtained in the same manner as in Example 3 except that in Example 16, the undrawn yarn was heat treated with a second roll and then wound. At this time, as shown in FIG. 7, a separate roll 40 for providing traverse vibration is installed near the second roll, and the spun yarn is wound on the second roll for 6 turns (yarn path pitch 5 mm), and then wound by the winder 17. It was. In Example 17, a crimped yarn of 56 dtex and 40 filaments was obtained in the same manner as in Example 3 except that the spin draw apparatus of FIG. 4 was used and the spun yarn was drawn, heat treated and then wound. At this time, the first roll (tandem type) 21 and the second roll (tandem type) 22 were each spun with 6 turns. A knitted fabric and a patch were prepared and evaluated. In Examples 16 to 17, yarn breakage did not occur in each step, and the yarn forming property was excellent. The conditions changed from Example 3 in Examples 16-17 are shown. The results of Examples 16 to 17 are shown in Table 6.

Example 16 (heat treatment of undrawn yarn)
Second roll temperature: 90 ° C
Example 17 (spin draw)
Base plate 3: discharge hole diameter 0.27 mm, discharge hole length 0.55 mm, number of holes 40
Discharge amount: 22.9 g / min. First roll (tandem type) Temperature: 60 ° C.
Second roll (tandem type) temperature: 150 ° C
Third roll temperature: 25 ° C
Fourth roll temperature: 25 ° C
First roll (tandem type) speed: 3000 m / min Second roll (tandem type) speed: 4500 m / min Third roll speed: 4350 m / min Fourth roll speed: 4220 m / min Winding speed: 4185 m / min Relax rate: 7%
Yarn feeding roller speed: 476 m / min False twisting magnification: 1.05

  As can be seen from a comparison between Example 3 and Examples 16 to 17, the undrawn yarn subjected to heat treatment or the drawn yarn subjected to spin draw, which is preferable in the present invention, has microcrystals in PTT. Since it is a raw material having a large amount, the cross-section is not easily deformed in the false twisting process, and a crimped yarn having a low degree of deformation can be obtained. And since it is hard to receive a deformation | transformation of a cross section, it turns out that the crimped yarn excellent in the uniformity is obtained. Furthermore, since a PTT crystal develops on the first heater and a crimped structure is set, a crimped yarn having excellent bulkiness can be obtained.

  Therefore, the knitted fabrics and patches obtained from Examples 16 to 17 were superior to Example 3.

(Example 18)
The same PTT as in Example 1 was used as the sheath component, and PLA1 obtained in Production Example 1 was used as the core component. At this time, PTT was vacuum-dried at 150 ° C. for 10 hours, PLA1 was vacuum-dried at 100 ° C. for 10 hours, and each water content was 50 ppm or less.

  Then, using the spinning machine shown in FIG. 1, the sheath component was introduced into the hopper 1, heated and melted by the extruder 2, measured by the gear pump 5, and led to the spinning pack 8. A core component was charged into the hopper 3, heated and melted by the extruder 4, weighed by the gear pump 6, and led to the spinning pack 8. Then, the sheath component and the core component were joined at the base 9 disposed inside the base to obtain a spun yarn. At this time, as the base 9, a base formed by combining three pieces as shown in FIG. Cooled and solidified by blowing cooling air to the spun yarn by the cooling device 11, and an oil agent was applied while concentrating the spun yarn by the oil supply device 13 at a position 2 m below the base, and the working nozzle 14 was operated with compressed air pressure 0 Was entangled at 2 MPa, taken up by the first roll 15 and the second roll 16, and wound with an undrawn yarn made of core-sheath composite fiber of 73 dtex and 40 filaments. At this time, the winding speed was adjusted so that the winding tension was constant, and the drum was replaced every 5 kg, and 20 5-kg packages (100 kg in total) were produced. No yarn breakage occurred during spinning, and the yarn-making property was extremely excellent. And the cross section of the single fiber of the obtained undrawn yarn was circular.

  Using the undrawn yarn as a raw yarn, a false twisted yarn was obtained using the false twist processing machine shown in FIG. The cheese 18 is set, the yarn 26 is pulled out, and is supplied to the supply roller 29 through the yarn path guides 25 and 27 to 28. Thereafter, the yarn 26 is heat-treated by the first heater 30 while being twisted by the triaxial twister 33, and the structure is fixed by the cooling plate 32 through the yarn path guide 31. At this time, the tension is measured between the cooling plate 32 and the triaxial twister 33 to obtain the twisting tension (T1), and the tension is measured between the triaxial twister 33 and the stretching roller 34, and the untwisting tension (T2). It was. The structure-fixed yarn 26 is wound up as a false twisted yarn 39 via a drawing roller 34 and then via a delivery roller 36 via yarn path guides 37 and 38. The second heater 35 was not used. A crimped yarn of 56 dtex, 40 filaments was obtained by applying the false twisting process. Twenty 4.9 kg wound packages (a total of 98 kg) were produced, but yarn breakage did not occur during false twisting, and the yarn forming property was extremely good.

The spinning conditions are described below.
・ Extruder temperature of sheath component: 260 ℃
・ Extruder temperature of core component: 220 ℃
-Spin block temperature: 255 ° C
-Weight fraction of core component: 30% by weight
Filter layer: Both sheath component and core component are filled with 30 g Morundan sand, 200 g. Filter: Both sheath component and core component are 20 μm non-woven filter. Plate 3 of the base (plate 3 in the schematic diagram of FIG. 3). The base where the sheath component and the core component merge): discharge hole diameter 0.26 mm, discharge hole length 0.5 mm, number of holes 40
・ Discharge rate: 20.9 g / min (1 pack 1 yarn, 40 filaments)
・ Cooling air: Uniflow with a cooling length of 1 m is used. Cooling air temperature 20 ° C, wind speed 0.5m / sec, base depth: 0.08m
・ Base heater temperature: 280 ℃
・ Base temperature: 253 ℃
・ Oil agent: For spinning oil, 70% by weight of polyether having a weight average molecular weight of 2000 as a smoothing agent, 8% by weight of polyether having a weight average molecular weight of 6000, 12% by weight of ether ester, other additives (antistatic agent, (Oxidizing agent, rust preventive agent) was adjusted to 10% by weight, and this oil was adjusted as a water emulsion to a concentration of 10% by weight, and about 0.8% by weight was adhered to the fiber as a pure oil component.
・ First roll speed: 3000 m / min ・ Second roll speed: 3000 m / min ・ First roll temperature: 25 ° C.
-Second roll temperature: 25 ° C
-Winding speed: 2970 m / min-Relaxation rate: 1%
The false twisting conditions are described below.
Feed roller speed: 370 m / min Stretch roller speed: 500 m / min First heater temperature: 130 ° C.
-False twisting magnification: 1.30
DY ratio: 1.35
・ T2 / T1: 1.3
・ Delivery roller speed: 480 m / min ・ Winding speed: 466 m / min ・ OF ratio 1: 4%
・ OF ratio 2: 3%

  When the cross section of the single fiber of the crimped yarn obtained was observed, the substantially circular shape was maintained and the degree of deformity was 1.1. The modulus of the crimped yarn of Example 18 was 30 cN / dtex, the elastic recovery rate was 92%, and it was a crimped yarn excellent in recoverability after removing the stress while stretching and contracting with a low force. Further, CR was 50%, which was extremely excellent in bulkiness, and U% (normal) was 0.8, which was excellent in the uniformity of the multifilament in the longitudinal direction. The fineness CV% was 2%, and the crimped yarn had a uniform thickness between single fibers. The crimped yarn had a strength of 2.7 cN / dtex, an elongation of 40%, a boiling water shrinkage of 11.3%, and a residual torque of 118 T / m. The cyclic dimer content was 1.8% by weight, and the total carboxyl end group concentration was 21.6 eq / ton. The crimped yarn after the wet heat treatment had a high strength of 2.5 cN / dtex and was excellent in hydrolysis resistance. The degree of dissociation of the center of gravity in the cross section of the single fiber was 0, and it was a crimped yarn not including a single fiber having spiral crimps.

  Using the crimped yarn of Example 18, a dyed knitted fabric was obtained based on the method described in the section T. The knitted fabric was a knitted fabric having a low modulus and a high elastic recovery rate in both the vertical and horizontal directions, and had soft stretch properties. Moreover, there was no dyeing spot over the entire knitted fabric, and it was a knitted fabric excellent in levelness. Moreover, it was a high-grade knitted fabric with a soft touch that was full of luxury and had no surface roughness.

  Using the obtained knitted fabric, a patch was prepared based on the method described in the section X. The patch was an excellent patch with no tension or irritation to the skin even after bending and stretching exercises. Further, it did not peel off or wrinkle, and had excellent characteristics as a patch.

  Since the crimped yarn and the knitted fabric of Example 18 had excellent characteristics as described above, they were used for clothing and industrial use. The results of Example 18 are shown in Table 7.

(Examples 19-20 and Comparative Examples 9-11)
In Example 18, a crimped yarn of 56 dtex and 40 filaments was obtained in the same manner as in Example 18 except that the weight fraction of the core component was changed by changing the discharge amount of the sheath component and the core component. . A knitted fabric and a patch were prepared and evaluated.

  In Examples 19 to 20, yarn breakage, fluff and the like did not occur in the spinning and false twisting steps, and the yarn production was excellent.

In Comparative Examples 9 to 10, thinning of the spun yarn during spinning was not stable, and yarn breakage occurred 12 times and 7 times in 100 kg spinning, respectively. Further, when false twisting a 100 kg raw yarn, yarn breakage occurred 12 times and twice, respectively, and the yarn forming property was extremely poor. The undrawn yarn package and the crimped yarn package were wound by the delayed recovery of PTT, the package was cured, and the wound foam was bad. In Comparative Example 11, the yarn breakage was 1 in the spinning process and the yarn breakage was 2 in the false twisting process. The weight fractions of the core components of Examples 19 to 20 and Comparative Examples 9 to 11 are shown below, and the results of Examples 18 to 20 and Comparative Examples 9 to 11 are shown in Table 7.
Example 19: Weight fraction of core component 20% by weight
Example 20: Weight fraction of core component 40% by weight
Comparative Example 9: Weight fraction of core component 0% by weight
Comparative Example 10: Weight fraction of core component 10% by weight
Comparative Example 11: Weight fraction of core component 50% by weight

  As can be seen from comparison between Example 19 and Comparative Examples 9 to 10, by using a crimped yarn containing a core component having a weight fraction of 20% by weight or more, the modulus is low and the elastic recovery rate is high. It can be seen that a crimped yarn having excellent uniformity can be obtained due to the effect of suppressing delayed recovery. As a result, it is understood that the knitted fabric made of crimped yarn has excellent levelness and feel, and even when it is used as a patch, it is an excellent patch with no tension or irritation to the skin. In addition, peeling and wrinkles do not occur, and it can be seen that satisfactory characteristics are expressed as a patch.

  Comparative Examples 5 and 6 are crimped yarns having a low modulus and a high elastic recovery rate. However, since the fineness CV% is particularly large, streaks are severe on the knitted fabric after dyeing, and the dyeing difference is stepwise in the knitting direction. It was what had. Further, the surface of the knitted fabric has a large roughness, and when used as a patch, the skin is strongly stimulated during bending and stretching movements and cannot be practically used.

  Further, as can be seen from a comparison between Example 20 and Comparative Example 11, the core component has a weight fraction of 40% by weight or less, and it is uniform without killing the characteristics of PTT having a low modulus and a high elastic modulus. It turns out that it becomes a crimped yarn excellent in the property and the bulkiness. When the core component is 40% by weight, the crimped yarn has excellent hydrolysis resistance and the crimped yarn has excellent durability. In addition, by containing a large amount of PTT with a low weight fraction of the core component, that is, excellent in elastic recovery, it is possible to suppress deformation of the cross section in the false twisting process and to reduce the degree of deformation of the crimped yarn. I understand. Moreover, it turns out that the thickness spot of a single fiber can also be made small by suppressing the deformation | transformation of a cross section.

  The crimped yarn of Comparative Example 11 has a high modulus and low elastic recovery, which is also reflected in the stretch properties of the knitted fabric. When used as a patch, there is a feeling of following the bending and stretching movements. Peeling and wrinkles occurred and the feeling of wearing was bad. In addition, due to the large degree of deformation of the crimped yarn, an apparent roughness was generated on the surface of the knitted fabric. And the fineness CV% of the crimped yarn was large and the uniformity was low, so that clear streaks were scattered on the knitted fabric, and the quality was low.

  As can be seen from a comparison of Examples 18 to 20, by making the weight fraction of the core component more preferable in the present invention, the uniformity of the crimped yarn, the bulkiness, and the hydrolysis resistance are improved. It turns out that it becomes an excellent crimped yarn in a well-balanced state, and becomes a better knitted fabric and a patch.

(Examples 21-22, Comparative Examples 12-13)
In Example 20, in Example 21 and Comparative Example 12, the temperature of the first heater during false twisting is used. In Example 22 and Comparative Example 13, in the spinning process, the base plate 3, discharge amount, spinning speed, winding A crimped yarn of 56 dtex and 40 filaments was obtained in the same manner as in Example 22 except that the take-up speed was changed and the speed of the supply roller was changed in the false twisting process. In Example 21, although not at a problematic level, yarn breakage occurred twice / 100 kg in the false twisting process. In Example 22, yarn breakage did not occur in each step, and the yarn forming property was excellent. On the other hand, in Comparative Examples 12 and 13, fluff frequently occurred in the false twisting process, yarn breakage of 14 times / 100 kg occurred, and the process passability was poor. The conditions changed from Example 20 in Examples 21 to 22 and Comparative Examples 12 to 13 are shown below. Table 8 shows the results of Examples 21 to 22 and Comparative Examples 12 to 13.

Example 21
First heater temperature: 150 ° C
Comparative Example 12
First heater temperature: 170 ° C
Example 22
Base plate 3: discharge hole diameter 0.28 mm, discharge hole length 0.5 mm, number of holes 40
Discharge amount: 24.8 g / min First roll speed: 4000 m / min Second roll speed: 4000 m / min Winding speed: 3960 m / min Yarn feeding roller speed: 417 m / min False twisting ratio: 1.20
Comparative Example 13
Base plate 3: discharge hole diameter 0.24 mm, discharge hole length 0.5 mm, number of holes 40
Discharge rate: 17.7 g / min First roll speed: 1800 m / min Second roll speed: 1800 m / min Winding speed: 1782 m / min Yarn feeding roller speed: 263 m / min False twisting magnification: 1.90

  As can be seen by comparing Examples 20 to 22 and Comparative Examples 12 to 13, the deformation of the cross-section in the false twisting process is suppressed, and the deformed degree of the crimped yarn of the present invention is 1.5 or less. It can be seen that the knitted fabric is excellent in levelness. And as can be seen from Examples 20 to 22, by adopting a preferred production method (first heater temperature, spinning speed) in the present invention, a crimped yarn having a smaller degree of irregularity is obtained, the surface is smooth, It can be seen that a knitted fabric without roughness can be obtained. At the same time, the thickness variation of the single fiber is reduced, and the knitted fabric is excellent in leveling. In the knitted fabrics of Comparative Examples 12 to 13, clear streaky stained spots were observed, the appearance quality was inferior, and the surface quality was inferior to the knitted fabrics of the examples. The patch obtained from the knitted fabric had a strong irritation and inferior wearing feeling when bending and stretching.

(Examples 23 to 26)
In Example 18, 56 dtex, 40 filaments were used in the same manner as in Example 18 except that the spinning plate 3 and the discharge rate were changed in the spinning process, and the speed of the yarn supplying roller was changed to change the false twisting magnification. Of crimped yarn was obtained. A knitted fabric and a patch were prepared and evaluated. In Example 25, although not at a problematic level, yarn breakage occurred once / 100 kg in the false twisting process. In Examples 23, 24, and 26, yarn breakage did not occur in each step, and the yarn forming property was excellent. In Examples 23 to 26, the conditions changed from Example 18 are shown below. Table 9 shows the results of Examples 23 to 26.

Example 23
Base plate 3: discharge hole diameter 0.25 mm, discharge hole length 0.5 mm, number of holes 40
Discharge rate: 19.4 g / min Yarn feeding roller speed: 400 m / min False twisting magnification: 1.25
Example 24
Base plate 3: discharge hole diameter 0.27 mm, discharge hole length 0.55 mm, number of holes 40
Discharge amount: 21.7 g / min Yarn feeding roller speed: 357 m / min False twisting magnification: 1.4
Example 25
Base plate 3: discharge hole diameter 0.28 mm, discharge hole length 0.6 mm, number of holes 40
Discharge amount: 23.2 g / min Yarn feeding roller speed: 333 m / min False twisting magnification: 1.5
Example 26
Base plate 3: discharge hole diameter 0.25 mm, discharge hole length 0.5 mm, number of holes 40
Discharge rate: 18.6 g / min Yarn feeding roller speed: 417 m / min False twisting magnification: 1.2

  As can be seen from a comparison between Example 18 and Examples 23 to 26, the crimped yarn of the present invention has no bulkiness between single fibers as a crimped yarn rich in bulkiness, and has excellent knitted fabric and sticking. It turned out to be an agent. And by using a crimped yarn having a CR of 40% or more, which is preferable in the present invention, it becomes a knitted fabric with a lower modulus and a higher elastic recovery rate, and when it is used as a patch, there is no skin tension, It can be seen that even in repeated bending and stretching movements, it peels off and becomes excellent without wrinkles.

  In addition, by using a crimped yarn having a CR of 60% or less, the crimped yarn has excellent mechanical properties, and the strength after wet heat treatment is increased. It turns out that a ground and a patch are obtained. In addition, since the crimped yarn has a small cross-sectional deformation and a high uniformity in the false twisting process, it can be seen that the leveling property is more excellent.

  Therefore, when the CR of the crimped yarn is 40 to 60%, the crimped yarn further has low modulus, bulkiness, uniformity, mechanical properties, and hydrolysis resistance, and the crimped yarn The knitted fabric made of the present invention was more excellent in levelness, feel and wearing feeling when used as a patch.

(Examples 27 to 30)
In Example 18, a 56 dtex crimped yarn of Examples 27 to 30 was used in the same manner as in Example 18 except that a base having a different discharge hole specification and number of filaments was used and the number of filaments of the crimped yarn obtained was changed. Got. A knitted fabric and a patch were prepared and evaluated. In Examples 27 and 28, although not at a problematic level, yarn breakage occurred once / 100 kg in the spinning process and false twisting process. In Examples 29 and 30, yarn breakage did not occur in each step, and the yarn forming property was excellent. In Examples 27 to 30, the conditions changed from Example 18 are shown below. The results of Examples 27 to 30 are shown in Table 10.
Base plate 3 of example 27: discharge hole diameter 0.19 mm, discharge hole length 0.4 mm, number of holes 72
Base plate 3 of example 28: discharge hole diameter 0.14 mm, discharge hole length 0.3 mm, number of holes 144
Base plate 3 of Example 29: discharge hole diameter 0.29 mm, discharge hole length 0.6 mm, number of holes 32
Plate 30 of base of Example 30: discharge hole diameter 0.37 mm, discharge hole length 0.8 mm, number of holes 20

  In addition, about the plates 1 and 2 of the nozzle | cap | die of Examples 27-30, the number of holes was changed according to the number of filaments.

  As can be seen from a comparison between Example 18 and Examples 27 to 30, the crimped yarn of the present invention is a core-sheath composite fiber containing a specific core component, so that it is a fine denier crimped yarn having a small single fiber fineness. It can also be seen that the fiber uniformity is excellent. It can be seen that a crimped yarn having a good bulkiness can be obtained from the characteristic of PTT having excellent elasticity. For this reason, a knitted fabric with a high-quality and soft touch feeling can be obtained by peach touch, and a patch excellent in wearing feeling can be obtained without any irritation to the skin.

  On the other hand, since the single fiber fineness is somewhat thick, it is possible to obtain a knitted fabric that is difficult to crimp and excellent in bulkiness and elastic recovery. It can also be seen that the crimped yarn is excellent in practical durability because the mechanical properties and hydrolysis resistance of the crimped yarn are increased.

  That is, a crimped yarn having a single fiber fineness within a range preferred in the present invention is a crimped yarn having a good balance in terms of low modulus, bulkiness, uniformity, mechanical properties, and hydrolysis resistance, The crimped yarn was excellent in leveling and touch feeling of the knitted fabric, and was excellent in wearing feeling when used as a patch.

(Examples 31-32, Comparative Examples 14-16)
In Example 31 and Comparative Example 14, a crimped yarn of 56 dtex and 40 filaments was obtained in the same manner as in Example 20 except that the specifications of the discharge holes in Example 20 were changed. In Example 32, a crimped yarn of 56 dtex and 40 filaments was obtained in the same manner as in Example 20 except that PLA2 was used as the core component. In Comparative Examples 15 to 16, crimped yarns of 56 dtex and 40 filaments were obtained in the same manner as in Example 20 except that the spin block temperature was changed. A knitted fabric and a patch were prepared and evaluated using the crimped yarns of Examples 31 to 32 and Comparative Examples 14 to 16, respectively.

In Examples 31 to 32, although not at a problematic level, yarn breakage occurred once / 100 kg in the spinning process and false twisting process. On the other hand, in Comparative Example 14, yarn breakage occurred 7 times / 100 kg in the spinning process, and yarn breakage occurred 5 times in the false twisting process, and Example 20 was superior in yarn production. In Comparative Examples 15 to 16, since the yarn breakage occurred 6 times and 8 times in the spinning process, and the yarn breakage occurred 6 times and 5 times in the false twisting process, Example 20 was superior in yarn production. . The conditions changed from Example 20 in each are shown below. Table 11 shows the results of Examples 31 to 32 and Comparative Examples 14 to 16.
Base plate 3 of Example 31: discharge hole diameter 0.20 mm, discharge hole length 0.4 mm, number of holes 40
Base plate 3 of Comparative Example 14: discharge hole diameter 0.19 mm, discharge hole length 0.4 mm, number of holes 40
PLA of Example 32: PLA-2
Spin block temperature of Comparative Example 15: 290 ° C
Spin block temperature of Comparative Example 16: 255 ° C.

  As can be seen by comparing Examples 20, 31, 32, and Comparative Examples 14 to 16, the production process (discharge linear velocity, spin block temperature) preferred in the present invention is adopted for the first time in the spinning process. It can be seen that uneven distribution of the core component can be suppressed. By adopting PLA having a high molecular weight as the core component, a crimped yarn having a smaller degree of dissociation of the center of gravity can be obtained. A crimped yarn with a lower center-of-gravity dissociation does not contain monofilaments with spiral crimps, making the surface of the knitted fabric smoother and smoother, and having better wearing feeling when used as a patch. Become. Since the uneven distribution of the core component is suppressed at the raw yarn stage, the cross-sectional deformation of the single fiber in the false twisting process can be suppressed, and a crimped yarn having a small degree of irregularity and excellent uniformity can be obtained.

(Example 33)
In Example 18, 56 dtex, 40 filaments were used in the same manner as in Example 18 except that the second heater 35 was used during false twisting, and the false twisting conditions, the base plate 3 in melt spinning, and the discharge amount were changed. A crimped yarn was obtained. A knitted fabric and a patch were prepared and evaluated. In Example 33, yarn breakage did not occur in each step, and the yarn forming property was excellent. The conditions changed from Example 18 are shown below. The results of Example 33 are shown in Table 12.

Example 33
Base plate 3: discharge hole diameter 0.24 mm, discharge hole length 0.5 mm, number of holes 40
Discharge rate: 17.7 g / min Second heater temperature: 100 ° C.
Delivery roller speed: 400 m / min Winding speed: 392 m / min OF ratio 1: 20%
OF ratio 2: 2%

  The crimped yarn of Example 33 was a crimped yarn having a boiling water shrinkage rate as low as 6% and a residual torque as low as 55 T / m as compared with Example 18. And it was a crimped yarn with good bulkiness, low modulus and high elastic recovery, excellent mechanical properties, hydrolysis resistance and uniformity. For this reason, the resulting knitted fabric was excellent in levelness and feel, and was excellent in wearing comfort of the patch.

(Examples 34 to 35)
In Example 20, a crimped yarn was obtained in the same manner as in Example 20 except that in Example 34, the undrawn yarn was heat treated with the second roll and then wound. At this time, as shown in FIG. 7, a separate roll 40 is provided in the vicinity of the second roll to apply traverse, and the spun yarn is wound on the second roll for 6 turns (yarn path pitch 5 mm), and then wound by the winder 17. It was. In Example 35, a crimped yarn of 56 dtex and 40 filaments was obtained in the same manner as in Example 20 except that the spin draw apparatus of FIG. 4 was used and the spun yarn was stretched, heat treated and then wound. . At this time, the first roll (tandem type) 21 and the second roll (tandem type) 22 were each spun with 6 turns. A knitted fabric and a patch were prepared and evaluated. In Examples 34 to 35, yarn breakage did not occur in each step, and the yarn forming property was excellent. The conditions changed from Example 20 in Examples 34-35 are shown. The results of Examples 34 to 35 are shown in Table 12.

Example 34 (heat treatment of undrawn yarn)
Second roll temperature: 90 ° C
Example 35 (spin draw)
Base plate 3: discharge hole diameter 0.27 mm, discharge hole length 0.55 mm, number of holes 40
Discharge amount: 22.9 g / min. First roll (tandem type) Temperature: 60 ° C.
Second roll (tandem type) temperature: 150 ° C
Third roll temperature: 25 ° C
Fourth roll temperature: 25 ° C
First roll (tandem type) speed: 3000 m / min Second roll (tandem type) speed: 4500 m / min Third roll speed: 4350 m / min Fourth roll speed: 4220 m / min Winding speed: 4185 m / min Relax rate: 7%
Yarn feeding roller speed: 476 m / min False twisting magnification: 1.05

  As can be seen from a comparison between Example 20 and Examples 34 to 35, the undrawn yarn subjected to heat treatment or the drawn yarn subjected to spin draw, which is preferable in the present invention, exhibits fine crystals in the PTT. Since it is a raw material having a large amount, the cross-section is not easily deformed in the false twisting process, and a crimped yarn having a low degree of deformation can be obtained. And since it is hard to receive a deformation | transformation of a cross section, it turns out that the crimped yarn excellent in the uniformity is obtained. Furthermore, since a PTT crystal develops on the first heater and a crimped structure is set, a crimped yarn having excellent bulkiness can be obtained. Therefore, the knitted fabrics and patches obtained from Examples 34 to 35 were superior to Example 20.

It is the schematic which shows the one aspect | mode of the spinning apparatus used in Example 1 of this invention. It is the cross-sectional schematic diagram (A) of a discharge hole explaining a discharge hole length and a discharge hole diameter, and a nozzle | cap | die lower surface part side plane cross-sectional schematic diagram (B). It is a schematic diagram which shows the one aspect | mode of the nozzle | cap | die used by this invention method, (a) is a cross-sectional schematic diagram of the nozzle | cap | die comprised by 3 sheets, (b) is an upper surface part side plane sectional drawing of 2 plates, (c). Is a side plane sectional view of the top surface of the three plates, and (d) is a side plane sectional view of the bottom surface of the three plates. It is the schematic which shows the one aspect | mode of the apparatus which performs the spin draw of this invention. It is the schematic which shows the one aspect | mode of the apparatus which performs false twist processing to the raw yarn of this invention. It is a side surface schematic diagram which shows the one aspect | mode of the single fiber which has a spiral crimp. It is the schematic which shows the one aspect | mode of the spinning and heat processing apparatus of this invention.

Explanation of symbols

1: sheath component hopper 2: sheath component extruder 3: core component hopper 4: core component extruder 5: sheath component gear pump 6: core component gear pump 7: spin block 8: spinning pack 9: base 10 : Cap heater
11: Uniflow cooling device 12: Spinning yarn 13: Oil supply device 14: Entangling nozzle 15: First roll 16: Second roll 17: Winder 18: Cheese package 19: Discharge hole length 20: Discharge hole diameter 21: First Roll (tandem type)
22: Second roll (tandem type)
23: Third roll 24: Fourth roll 25, 27, 28, 31, 37, 38: Thread guide 26: Yarn 29: Supply roller 30: First heater 32: Cooling plate 33: Triaxial twister 34: Stretching Roller 35: Second heater 36: Delivery roller 39: False twisted yarn 40: Separate roll

Claims (8)

  The sheath component is made of polytrimethylene terephthalate and the core component is made of a core-sheath composite fiber made of polyester other than polytrimethylene terephthalate, and the weight fraction of the core component is 20 to 40% by weight. A crimped yarn having an irregularity of 1.5 or less.   The crimped yarn according to claim 1, wherein the core component is polyethylene terephthalate.   The crimped yarn according to claim 1, wherein the core component is polylactic acid.   The crimped yarn according to any one of claims 1 to 3, wherein the crimped yarn is a false twisted yarn.   The crimped yarn according to any one of claims 1 to 4, wherein the fineness of the single fiber is 0.1 to 1.8 dtex.   The center-of-gravity dissociation degree calculated by dividing the distance between the center of gravity of the core component and the center of gravity of the single fiber in the cross section of the single fiber by the diameter of the single fiber is 0.1 or less. The crimped yarn according to crab.   A fiber structure comprising the crimped yarn according to any one of claims 1 to 6.   A patch comprising the fiber structure according to claim 7.

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