JP2009019295A - Moisture-sensitive crimped conjugated fiber - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a conjugated fiber having both excellent air permeability self-control function and excellent moisture-absorbing or releasing performance. <P>SOLUTION: A conjugated fiber in which a polyamide component is bound to a polyester component in a side-by-side type is characterized by containing a polyether ester amide in the polyamide component in an amount of 5 to 20 wt.% based on the weight of the polyamide component and further containing the polyether ester amide in the polyester component in an amount of ≥5 wt.% and <15 wt.% based on the weight of the polyester component. The polyether ester amide is derived from a polyamide (a) having carboxyl groups at both the ends and having a number-average mol.wt. of 500 to 5,000 and a bisphenol compound-ethylene oxide adduct (b) having a number-average mol.wt. of 1,600 to 3,000, and has a relative viscosity of 1.5 to 3.0 (0.5 wt.% m-cresol solution, 25°C). <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a functional composite fiber that has a breathable self-regulating function that reversibly changes the crimp rate in response to a change in humidity, and also has moisture absorption / release performance.

  Clothing made from woven and knitted fabrics of natural fibers such as cotton and wool reversibly changes with humidity, so the knitted fabric's eyes open according to the surrounding humidity and air permeability is improved. , The characteristics of lowering the humidity of the air layer formed between the body and clothing and between clothing, so-called breathable self-regulation function, and moisture absorption and desorption performance that the fibers themselves absorb moisture such as sweat ing. Therefore, when wearing clothing using such natural fibers, there is little feeling of discomfort due to changes in ambient humidity and sweat.

  Following such natural fibers, attempts have been made to impart a crimpable self-regulating function to hygroscopic synthetic fibers. For example, a composite fiber that joins a modified polyester and polyamide in a side-by-side type and imparts a reversible shape change to a humidity change has been proposed (see, for example, Patent Document 1 and Patent Document 2). However, although the crimp rate reversibly changes in response to changes in humidity, the low hygroscopicity, which is one of the disadvantages of synthetic fibers, makes it uncomfortable because the fibers cannot absorb moisture quickly when sweating. There is a problem of feeling. In addition, in the method of imparting high moisture absorption / release characteristics by blending a fiber component with a hygroscopic polymer, the moisture absorption / release performance is improved, but there is almost no crimp change with respect to humidity change, and it can be made between clothing. In addition, the air permeability self-regulation function of lowering the humidity of the air layer is poor and satisfactory performance is not satisfied (for example, see Patent Document 3). As described above, it has been difficult to provide a synthetic fiber having both a breathable self-adjusting function and moisture absorption performance with the conventional technology.

JP 2004-360094 A JP 2004-124305 A Japanese Patent Laid-Open No. 2003-213524

  An object of the present invention is to solve the above-mentioned problems and to provide a composite fiber having both excellent air permeability self-adjusting function and moisture absorption performance.

  The present invention is a composite fiber in which a polyamide component and a polyester component are bonded in a side-by-side manner, and a polyamide (a) having a carboxyl group at both ends and a number average molecular weight of 500 to 5,000 and a number average molecular weight of 1, Polyether ester amide derived from ethylene oxide adduct (b) of bisphenols of 600 to 3,000 and having a relative viscosity of 1.5 to 3.0 (0.5 wt% m-cresol solution, 25 ° C.) In the polyamide component so as to be 5 to 20% by weight based on the weight of the polyamide component, and in the polyester component so as to be 5% by weight or more and less than 15% by weight based on the weight of the polyester component. The above-mentioned problem can be solved by this composite fiber.

  The composite fiber which can provide the fabric which has the outstanding moisture absorption performance by this invention and has the outstanding air permeability self-adjustment function can be obtained.

  The polyamide component in the present invention is a polymer having an amide bond in the main chain, and examples thereof include nylon 4, nylon 6, nylon 12, nylon 46, nylon 66, and the like. Nylon 6 and nylon 66 are particularly preferable from the viewpoints of cost, versatility, and yarn production. These polyamide components may be copolymerized with known components, or these polyamide components contain pigments such as titanium oxide and carbon black, known antioxidants, antistatic agents, light-proofing agents, etc. You may let them.

  On the other hand, examples of the polyester component of the present invention include polyalkylene terephthalate. Among them, terephthalic acid is the main acid component, and the main component is an alkylene glycol component having 2 to 6 carbon atoms, that is, at least one glycol selected from ethylene glycol, trimethylene glycol, tetramethylene glycol, pentamethylene glycol and hexamethylene glycol. It is preferable to use polyester as a glycol component. Such a polyester may be produced by an arbitrary method. For example, polyethylene terephthalate will be described. A lower alkyl ester of terephthalic acid such as dimethyl terephthalate and ethylene glycol are obtained by directly esterifying terephthalic acid and ethylene glycol. Is directly esterified, or terephthalic acid and ethylene oxide are reacted to produce a glycol ester of terephthalic acid and / or a low polymer thereof. Next, the product is produced by heating under reduced pressure to cause a polycondensation reaction until a desired degree of polymerization is achieved.

  In this polyester, a part of the terephthalic acid component may be replaced with another bifunctional carboxylic acid component. Examples of such carboxylic acids include isophthalic acid, phthalic acid, dibromoterephthalic acid, naphthalenedicarboxylic acid, diphenyldicarboxylic acid, diphenethanedicarboxylic acid, bifunctional aromatic carboxylic acids such as β-oxyethoxybenzoic acid, and sebacin. Bifunctional aliphatic dicarboxylic acid such as acid, adipic acid and oxalic acid, 1,4-cyclohexanedicarboxylic acid and the like can be mentioned. Further, a part of the glycol component may be replaced with another glycol component. Examples of the glycol component include cyclohexane-1,4-dimethanol, neopentyl glycol, bisphenol A, bisphenol S, 2,2-bis (3 , 5-dibromo-4- (2-hydroxyethoxy) phenyl) propane, and aliphatic, alicyclic and aromatic diols. Further, the above-mentioned polyester may be obtained by blending and melting a small amount of other polymers as required, or by using a chain branching agent such as pentaerythritol, trimethylolpropane, trimellitic acid in a small proportion. In addition, the polyester of the present invention may of course be added with conventionally known antioxidants and anti-coloring agents in addition to pigments such as titanium dioxide and carbon black as in the case of ordinary polyesters.

  The side-by-side type composite fiber of the present invention can have any fineness, cross-sectional shape, and composite form, but a single yarn fineness of about 1.5 to 5.0 dtex is appropriate. The lower and upper limits of these fineness ranges correspond to 15 microns, which is the single yarn diameter of the highest grade wool, and 30 microns, which is the single yarn diameter of general-purpose wool. Furthermore, when the conjugate fiber of the present invention is a hollow conjugate fiber, it has high sensitivity to humidity and high bulkiness. Moreover, the area ratio in the cross section of the composite fiber of the polyamide component and the polyester component is preferably in the range of polyamide component / polyester component = 30/70 to 70/30, more preferably in the range of 40/60 to 60/40. .

  The total fineness of the multifilament when the composite fiber of the present invention is a multifilament of several single yarns is not particularly limited, but can be used in the range of 40 to 200 dtex used as a normal clothing material. In addition, the confounding process may be performed as needed.

  The polyether ester amide used in the present invention is preferably an ethylene oxide addition of a polyamide (a) having a carboxyl group at both ends and having a number average molecular weight of 500 to 5,000 and a bisphenol having a number average molecular weight of 1,600 to 3,000. Derived from object (b). "Induction" means that it is obtained by reacting both components, and can also be understood as being obtained by copolymerization.

  The polyamide (a) having carboxyl groups at both ends preferably comprises a polyamide portion and a molecular weight regulator. The polyamide portion is composed of at least one of (1) a lactam ring-opening polymer, (2) a polycondensate of aminocarboxylic acid, or (3) a polycondensate of dicarboxylic acid and diamine. Among these, the lactam of (1) includes butyrolactam, valerolactam, caprolactam, enantolactam, laurolactam, undecanolactam and the like. Examples of the aminocarboxylic acid (2) include ω-aminocaproic acid, ω-aminoenanthic acid, ω-aminopergonic acid, ω-aminocapric acid, 11-aminoundecanoic acid, and 12-aminododecanoic acid. Examples of the dicarboxylic acid (3) include adipic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, and isophthalic acid. Examples of the diamine (3) include tetramethylene diamine, pentamethylene diamine, hexamethylene diamine, heptamethylene diamine, octamethylene diamine, and decamethylene diamine. These lactams, aminocarboxylic acids, dicarboxylic acids, and diamines are collectively referred to as polyamide part-forming monomers.

  What was illustrated as a polyamide part formation monomer of the polyamide (a) which has a carboxyl group in both said terminal may use 2 or more types together. Among these, caprolactam, 12-aminododecanoic acid and adipic acid-hexamethylenediamine are preferable, and caprolactam is particularly preferable.

  The above polyamide (a) having carboxyl groups at both ends further uses a dicarboxylic acid component having 4 to 20 carbon atoms as a molecular weight regulator, and in the presence thereof, the polyamide part-forming monomer is opened by a conventional method. It can be obtained by polymerization or polycondensation. Examples of the dicarboxylic acid having 4 to 20 carbon atoms include fatty acid dicarboxylic acids such as succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanediic acid, and dodecanediic acid; terephthalic acid, isophthalic acid, Aromatic dicarboxylic acids such as phthalic acid or naphthalenedicarboxylic acid; aliphatic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid or dicyclohexyl-4,4-dicarboxylic acid; or sodium 5-sulfoisophthalate or 5-sulfo Examples include 5-sulfoisophthalic acid alkali metal salts such as potassium isophthalate. Of these, preferred are aliphatic dicarboxylic acids, aromatic dicarboxylic acids, and alkali metal salts of 5-sulfoisophthalic acid. More preferred are adipic acid, terephthalic acid, and sodium 5-sulfoisophthalate.

  When the polyamide part-forming monomer is subjected to ring-opening polymerization or polycondensation by a conventional method, the average degree of polymerization is preferably from 2 to 10, more preferably from 3 to 8. As a result, the number average molecular weight of the polyamide portion is 100 to 1,000, more preferably 300 to 700.

  Furthermore, the polyamide (a) having a carboxyl group at both ends is a component having a polyamide moiety added to both ends of a dicarboxylic acid component having 4 to 20 carbon atoms, which is a molecular weight regulator, and a polyamide portion added to one end. Or a mixture of a component having a polyamide moiety at both ends and a component having a polyamide moiety at one end. In the case of a mixture, a molar ratio of 1 to 10 moles of the component having the polyamide moiety at both ends to 1 mole of the component to which the polyamide moiety is imparted at one end is preferable. More preferably, it is 3 to 8 moles of the component imparted to both ends with respect to 1 mole of the component imparted to one end. And the quantity of the component which has a carboxyl group of the above-mentioned polyamide part formation monomer is adjusted suitably so that it may have a carboxyl group in both ends. If only the lactam and / or aminocarboxylic acid is used as the polyamide part-forming monomer, the molecular weight modifier is a dicarboxylic acid component, so that the polyamide (a) having carboxyl groups at both ends can be easily produced. When a polycondensate of dicarboxylic acid and diamine is used as the polyamide part-forming monomer, for example, a polyamide (a) having carboxyl groups at both ends by using a method such as reacting the dicarboxylic acid again at the end of the polymer. Can be manufactured.

  The number average molecular weight of the polyamide (a) having a carboxyl group at both ends is usually 500 to 5,000, preferably 500 to 3,000. When the number average molecular weight is less than 500, the heat resistance of the polyether ester amide itself is lowered. On the other hand, when it exceeds 5,000, the reactivity is lowered, so that much time is required for producing the polyether ester amide. In order to make the number average molecular weight within this range, it is possible to select a dicarboxylic acid component having 4 to 20 carbon atoms to be a molecular weight regulator and appropriately set the reaction conditions in the polymerization of the polyamide portion.

  Further, in the ethylene oxide adduct (b) of bisphenols, the bisphenols include bisphenol A (4,4′-dihydroxydiphenyl-2,2-propane), bisphenol F (4,4′-dihydroxydiphenylmethane), bisphenol S. (4,4′-dihydroxydiphenylsulfone) and 4,4′-dihydroxydiphenyl-2,2-butane are exemplified, and among these, bisphenol A is preferable.

  The ethylene oxide adduct (b) of the above bisphenols can be obtained by adding ethylene oxide to these bisphenols by a conventional method. Also, other alkylene oxides (propylene oxide, 1,2-butylene oxide, 1,4-butylene oxide, etc.) can be used in combination with ethylene oxide, but the amount of other alkylene oxide used is based on the weight of the total ethylene oxide used. Usually, it is 10% by weight or less.

  The adduct (b) preferably has an average of 20 to 70 moles of ethylene oxide and other alkylene oxides (hereinafter referred to as ethylene oxide or the like) polymerized with respect to the two hydroxyl groups of the bisphenols. More preferably, 32 to 60 mol of ethylene oxide or the like is polymerized. That is, it is an adduct in which 10 to 35 mol, more preferably 16 to 30 mol, and still more preferably 16 to 20 mol of ethylene oxide or the like is polymerized (added) with respect to one hydroxyl group of bisphenol.

  The number average molecular weight of the adduct (b) is usually 1,600 to 3,000, and it is particularly preferable to use one having an ethylene oxide addition mole number of 32 to 60. When the number average molecular weight is less than 1,600, the antistatic property becomes insufficient. On the other hand, when it exceeds 3,000, the reactivity is lowered, so that a great amount of time is required for producing the polyetheresteramide. The number average molecular weight is preferably 1,800 to 2,400, and the number of added moles such as ethylene oxide is more preferably 32 to 40. In order to make the number average molecular weight within this range, the molecular weight of bisphenols is taken into consideration, and the number of added moles of ethylene oxide or the like can be adjusted.

  The above adduct (b) is used in the range of 20 to 80% by weight based on the total weight of the above (a) and (b) in the polyether ester amide. If the amount of the adduct (b) is less than 20% by weight, the antistatic property of the polyether ester amide is inferior. On the other hand, if it exceeds 80% by weight, the heat resistance of the polyether ester amide is lowered, which is not preferable. More preferably, the adduct (b) is used in the range of 40 to 70% by weight based on the total weight of the above (a) and (b).

  The relative viscosity of the polyether ester amide used in the present invention is 1.5 to 3.5 (0.5 wt%, m-cresol solution, 25 ° C.), preferably 2.0 to 3.0. If it is less than 1.5, the difference in melt viscosity from the base polymer component (polyamide component and polyester component) to be kneaded becomes large, so that it tends to stay in the conduit or the spinning pack. It tends to occur and the quality of the resulting composite fiber is not stable. On the other hand, in the range exceeding 3.5, it becomes a cause of yarn breakage during yarn production.

Moreover, the composition of the polyetheresteramide of the present invention is a very important requirement for compatibility with the polyester component. The polyether ester amide used in the present invention has a polymer composition in which the difference between the compatibility parameter of the polyester and the compatibility parameter of the polyether ester amide is within a range of ± 0.5 (J / cm ³ ) ^0.5. Is necessary. For example, when polyethylene terephthalate is selected as the polyester component, since the compatibility parameter is 20.9 (J / cm ³ ) ^0.5 , the compatibility parameter of the polyether ester amide is 20.4 to 21. .4 (J / cm ³ ) Must be in the range of ^0.5 . If this range is exceeded, the interfacial adhesion between the polyester component and the polyether ester amide polymer is insufficient, and whitening due to interfacial peeling occurs due to post-processing steps and friction during wearing. Preferably, it is within ± 0.3 (J / cm ³ ) ^{0.5 with} respect to the base polyester component.

Although the following manufacturing method (1) or manufacturing method (2) is illustrated as a manufacturing method of the polyetheresteramide of this invention, it is not specifically limited.
Production method (1): A method in which a polyamide part-forming monomer and a dicarboxylic acid are reacted to form a polyamide (a), and an ethylene oxide adduct (b) of a bisphenol is added thereto, and a polymerization reaction is carried out at high temperature and reduced pressure. .
Production method (2): Polyamide partial monomer (dicarboxylic acid) and the above adduct (b) are simultaneously charged in a reaction vessel and subjected to pressure reaction at high temperature in the presence or absence of water as an intermediate ( A method in which a) is produced, and then a polymerization reaction between (a) and (b) is carried out under reduced pressure.

  A known esterification catalyst is usually used in the polymerization reaction of the polyamide (a) having a carboxyl group at both ends and having a number average molecular weight of 500 to 5,000 and an ethylene oxide adduct (b) of bisphenols. . Examples of the esterification catalyst include an antimony catalyst such as antimony trioxide, a tin catalyst such as monobutyltin oxide, a titanium catalyst such as tetrabutyl titanate, a zirconium catalyst such as tetrabutyl zirconate, and an acetic acid such as zinc acetate. Examples thereof include metal salt-based catalysts. The usage-amount of a catalyst is 0.1 to 5 weight% normally with respect to the total weight of (a) and (b).

  The amount of the polyether ester amide added to the polyamide component needs to be 5 to 20% by weight based on the weight of the polyamide component. Preferably, it is in the range of 5 to 10% by weight. The cause is not clear in the spinning of the side-by-side type composite fiber of the polyamide component and the polyester component, but when the addition amount of the polyether ester amide exceeds 20% by weight, it tends to be impossible to spin stably for a long time. That is, the spinning tone tends to deteriorate. This weight range of the polyamide component and the polyether ester amide can be achieved by melt-kneading the composite fiber while adjusting the discharge amount from the extruder by the gear pump.

  The amount of the polyether ester amide added to the polyester component needs to be 5% by weight or more and less than 15% by weight based on the weight of the polyester component. If it is less than 5% by weight, a composite fiber having a sufficient moisture absorption rate cannot be obtained. On the other hand, if it is 15% by weight or more, ΔTC is less than 5%, and the breathable self-regulating function is lowered. In order to make it into this weight range, it can achieve by the method similar to kneading | mixing the above-mentioned polyamide component and polyetheresteramide.

In the conjugate fiber of the present invention, the moisture absorption rate after leaving the conjugate fiber in an atmosphere of 20 ° C. × 65% RH (relative humidity 65%) for 4 hours is MR ₁ , and the conjugate fiber is 35 ° C. × 95% RH ( when the moisture absorption rate after allowed to stand for 4 hours in an atmosphere of 95% relative humidity) was MR _2, moisture absorption difference ΔMR of the following formula that is 1.0% or more, this as woven or knitted fabric It is preferable from the viewpoint of comfort when used for clothing.
ΔMR = MR ₂ −MR ₁ ≧ 1.0%
[In the above formula, MR ₁ is the moisture absorption rate after leaving the composite fiber in an atmosphere of 20 ° C. × 65% RH (relative humidity 65%) for 4 hours, MR ₂ is 35 ° C. × 95% RH (relative The moisture absorption rate after leaving for 4 hours in an atmosphere of 95% humidity) is shown. ]

Moreover, in the composite fiber in this invention, after leaving a composite fiber for 4 hours in the atmosphere of 20 degreeC x 65% RH (relative humidity 65%), 1.77 * 10 < ^-3 > cN / dtex (2 mgf / de) The crimp ratio under the load of TC is TC ₁ and the composite fiber is left to stand in an atmosphere of 35 ° C. × 95% RH (95% relative humidity) for 4 hours, 1.77 × 10 ⁻³ cN / dtex (2 mgf / when the percentage of crimp under a load of de) was TC _2, it is preferable moisture absorption index difference ΔTC represented by the following formula is 5.0% or more.
ΔTC = TC ₂ −TC ₁ ≧ 1.5%
[In the above formula, TC ₁ is the crimp rate under a load of 1.77 × 10 ⁻³ cN / dtex after leaving the composite fiber in an atmosphere of 20 ° C. × 65% RH (relative humidity 65%) for 4 hours. , TC ₂ indicates the crimp rate under a load of 1.77 × 10 ⁻³ cN / dtex after leaving the composite fiber in an atmosphere of 35 ° C. × 95% RH (relative humidity 95%) for 4 hours. ]

  Thus, in order for the composite fiber to have a ΔMR of 1.0% or more and a ΔTC of 1.5% or more, a predetermined amount of the above polyether ester amide is blended in the polyamide component and the polyester component. It can be achieved by a side-by-side type composite fiber composed of a polyester component and a polyamide component.

Hereinafter, the manufacturing method for obtaining the composite fiber of this invention is demonstrated.
Any conventionally known method can be employed for the composite spinning of the polyamide component and the polyester component in a side-by-side manner. For example, as described in Japanese Patent Application Laid-Open No. 2000-144518, the discharge holes on the high viscosity component side and the low viscosity component side are separated, and the discharge linear velocity on the high viscosity side is reduced (the discharge cross-sectional area is increased). Using a spinneret, a spun yarn can be obtained by a method in which molten polyester is passed through the high-viscosity side discharge holes and molten polyamide is passed through the low-viscosity side discharge holes and bonded and cooled and solidified. In the present invention, a side-by-side hollow composite fiber may be formed by appropriately designing the spinneret at this time. In addition to the so-called separate rolling method, the yarn obtained by spinning is once wound up and then stretched and further heat treated as necessary. Further, it is necessary to stretch the undrawn yarn without winding it once. Either of the so-called direct extension methods, in which heat treatment is performed according to the above, can be employed. As the spinning speed in the above spinning, for example, a spinning speed of about 1000 to 3500 m / min which is usually employed can be adopted. In addition, in the stretching and heat treatment, it is preferable to set conditions so that the breaking elongation after stretching is 10 to 60%, usually about 20 to 45%, from the viewpoint of crimping, weaving and knitting.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, these examples are for helping the understanding of the present invention, and the description is not intended to limit the examples to be consistent with the gist of the present invention. In addition, each physical-property value in an Example was measured with the following method.

(1) Moisture absorption The composite fiber of the present invention was conditioned for 4 hours in a constant temperature and humidity chamber at 20 ° C. × 65% RH (relative humidity 65%) or 35 ° C. × 95% RH (relative humidity 95%). The moisture absorption rate was calculated from the weight of the absolutely dry sample and the weight of the humidity control sample by the following formula.
Moisture absorption rate MR (%) = (weight after conditioning-weight when absolutely dry) × 100 / weight when completely dried (2) Difference in moisture absorption rate (ΔMR)
The difference in moisture absorption rate (ΔMR) is the moisture absorption rate MR ₁ after standing for 4 hours in an atmosphere of 20 ° C. × 65% RH (relative humidity 65%), and the composite fiber is 35 ° C. × 95% RH (95% relative humidity). ) And the moisture absorption rate MR ₂ after standing for 4 hours in the atmosphere, and a value calculated using the following formula.
ΔMR = MR ₂ −MR ₁
(3) Crimp rate (TC) and crimp rate difference (ΔTC)
Take the composite fiber in a 30 cm-long casserole and apply a load of 1.77 × 10 ⁻³ cN / dtex (2 mgf / de) to treat it in boiling water for 30 minutes to develop crimps, and then air dry for 24 hours. The sample for crimping rate measurement was prepared. After the sample was left in an atmosphere of 20 ° C. × 65% RH (relative humidity 65%) for 4 hours, the crimp rate under a load of 1.77 × 10 ⁻³ cN / dtex (2 mgf / de) was expressed as TC. _{It was set to 1} . On the other hand, the crimp rate under a load of 1.77 × 10 ⁻³ cN / dtex (2 mgf / de) after the sample was left in an atmosphere of 35 ° C. × 95% RH (relative humidity 95%) for 4 hours. It was used as a TC _2. Further, the crimp rate difference (ΔTC) of the composite fiber yarn due to moisture absorption was calculated using the following formula.
ΔTC = TC ₂ −TC ₁
(4) Intrinsic viscosity (IV)
For polyethylene terephthalate, a certain amount of the sample was weighed and obtained at 35 ° C. according to a conventional method using o-chlorophenol as a solvent. Nylon 6 was similarly measured at 30 ° C. using an equal mass mixed solvent of phenol / tetrachloroethane.
(5) Number average molecular weight The number average molecular weight of a polyamide (a) part having a carboxyl group at both ends and a number average molecular weight of 500 to 5,000 and an ethylene oxide adduct (b) part of a bisphenol is measured by heavy trifluoro NMR was measured after dissolving in a mixed solvent of equal mass of acetic acid / deuterochloroform. From the measurement results, the repeating unit of each part was specified, and the number average molecular weight was determined from the results.
(6) Weight ratio of polyether ester amide It can be controlled by adjusting the conditions with a gear pump during the production of the composite fiber, but the polyamide part and the polyester part forming the composite fiber can be controlled according to the method described in (5). The weight ratio of the polyether ester amide in the polyamide component or the polyester component can also be calculated by performing NMR measurement and analyzing the result.

[Examples 1-3, Comparative Examples 1-3]
Nylon 6 (Ny-6) having an intrinsic viscosity (IV) of 1.1 dL / g and a polyethylene terephthalate chip (IV = 0.39 dL / g) blended with the polyether ester amide of the weight% shown in Table 1; Is melt-spun at a spinning temperature of 290 ° C. and a spinning speed of 1000 m / min, and then drawn at a drawing temperature of 60 ° C. and a draw ratio of 2.5 times without winding, and further heat set at 130 ° C. Got. As a result, a crimped composite fiber of 84 dtex / 24 fil (the number of filaments) was bonded in a side-by-side manner with a weight ratio of nylon 6 blended with polyetheresteramide and polyethylene terephthalate blended with polyetheresteramide at 50:50. (Example 1). In Examples 2-3 and Comparative Examples 1-3, Ny-6, except that the weight addition ratio of the polyether ester amide in polyethylene terephthalate is changed as shown in Table 1 under the same conditions as in Example 1. 84 dtex / 24 fil crimped composite fiber was obtained. The physical properties of the obtained composite fiber are shown in Table 1. In Examples 1, 2, and 3, since the polymer composition and blend amount of polyetheresteramide (hereinafter referred to as PEEA) are appropriate, the moisture absorption rate and the crimp rate are values that can solve the problems of the present invention. A composite fiber that can be realized and has excellent performance and quality was obtained.

  Moreover, since the Ny-6 component and the polyethylene terephthalate component did not add PEEA in Comparative Example 1, the performance was insufficient in terms of achieving the object of the present invention in terms of moisture absorption. In Comparative Example 2, the amount of PEEA added in the polyester component (polyethylene terephthalate) was large, so that the crimping performance was insufficient. On the other hand, in Comparative Example 3, since the amount of PEEA added in the Ny-6 component was too large, there was a problem in stable productivity in the spinning process.

[Examples 4-7, Comparative Examples 4-5]
Various PEEAs with different number average molecular weight of polyamide (a) part having carboxyl groups at both ends and different number average molecular weight of ethylene oxide adduct (b) part of bisphenols (using bisphenol A) and different relative viscosities are used. The experiment was conducted in the same manner as in Example 1. Table 2 shows the physical properties of the obtained composite fibers.

  In Examples 4 to 7, the number average molecular weight and relative viscosity of the PEEA portion were optimum, and composite fibers having the performance capable of solving the problems of the present invention were obtained. On the other hand, in Comparative Example 4, since the number average molecular weight of the polyamide (a) part having carboxyl groups at both ends was small, the heat resistance in the spinning process was insufficient and the yarn breakage occurred at the spinning stage. In Comparative Example 5, the number average molecular weight of the ethylene oxide adduct (b) portion of bisphenols (using bisphenol A) was small, so that the problem of insufficient hygroscopicity occurred.

  The composite fiber which can provide the fabric which has the outstanding moisture absorption performance by this invention and has the outstanding air permeability self-adjustment function can be obtained. This composite fiber can be expected to be applied to, for example, clothing fabrics that require the required properties of moisture absorption and quick drying.

Claims (3)

  A composite fiber in which a polyamide component and a polyester component are joined in a side-by-side manner, and a polyamide (a) having a carboxyl group at both ends and a number average molecular weight of 500 to 5,000 and a number average molecular weight of 1,600 to 3, Polyether ester amide derived from ethylene oxide adduct (b) of 000 bisphenols and having a relative viscosity of 1.5 to 3.0 (0.5 wt% m-cresol solution, 25 ° C.) A composite fiber comprising 5 to 20% by weight based on the weight of the polyamide component in the component and 5% by weight or more to less than 15% by weight based on the weight of the polyester component in the polyester component. The composite fiber according to claim 1, wherein a difference in moisture absorption (ΔMR) represented by the following formula is 1.0% or more.
ΔMR = MR ₂ −MR ₁
[In the above formula, MR ₁ is the moisture absorption rate after leaving the composite fiber in an atmosphere of 20 ° C. × 65% RH (relative humidity 65%) for 4 hours, MR ₂ is 35 ° C. × 95% RH (relative The moisture absorption rate after leaving for 4 hours in an atmosphere of 95% humidity) is shown. ] The composite fiber according to claim 1 or 2, wherein a crimp rate difference (ΔTC) represented by the following formula is 5.0% or more.
ΔTC = TC ₂ −TC ₁
[In the above formula, TC ₁ is the crimp rate under a load of 1.77 × 10 ⁻³ cN / dtex after leaving the composite fiber in an atmosphere of 20 ° C. × 65% RH (relative humidity 65%) for 4 hours. , TC ₂ indicates the crimp rate under a load of 1.77 × 10 ⁻³ cN / dtex after leaving the composite fiber in an atmosphere of 35 ° C. × 95% RH (relative humidity 95%) for 4 hours. ]