JP2011208329A - Core-sheath composite fiber yarn and woven or knitted fabric - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a yarn which comprises a composite fiber containing a specific component and having a specific structure and has a good spinnability, and to provide a woven or knitted fabric which exhibits an excellent heat insulating effect, is dyeable with a white or light color and prevents uneven dyeing.SOLUTION: The core-sheath composite fiber yarn comprises a composite fiber including a sheath section that consists of a polyester polymer A containing 0.01-0.3 mass% of a fluorescent brightener, and a core section that consists of a polyester polymer B containing 5-25 mass% of a metal oxide infrared absorber. The mass ratio of both the polyester polymers (A/B) is 90/10-40/60. A fiber cross section is a flattened cross section with 2.0-6.0 degree of flatness. The polyester polymers are bonded along the contour of the fiber outer circumference.

Description

  The present invention relates to a yarn composed of fibers having a specific structure and containing a specific component, and a woven or knitted fabric using the yarn and having excellent heat retention, whiteness and dyeability.

  Conventional sports clothing such as winter clothing, skiing, mountain climbing, etc. often used clothing with a three-layer structure using batting. Such clothing is composed of three layers, surface layer, batting and lining, and the air insulation layer is made by batting to enhance the heat retaining performance, but the clothing composed of three layers is heavy and lacks sportiness was there.

  In addition, a heat retaining fabric in which a metal such as aluminum or chromium is coated on a woven or knitted fabric is also known. However, when such a fabric is used as a garment, there is a problem in that the performance of the fabric due to the coating is deteriorated and various performances are deteriorated due to repeated use.

  In order to solve such a problem, for example, in Patent Document 1, the core component is polyethylene terephthalate containing 2.5% by mass of zirconium silicide having an average particle diameter of 0.8 μm as the core component and polyethylene terephthalate as the sheath component. A core-sheath type composite fiber having a single yarn fineness of 2.8 dtex by composite melt spinning with / sheath = 6/4 has been proposed.

  Further, Patent Document 2 proposes a composite fiber which is also a core-sheath type composite fiber, and the cross-sectional shape of the core part including the infrared fine particles has an irregular cross-sectional shape having 5 to 30 protrusions. .

JP-A-5-9804 JP 2009-41137 A

  In the composite fiber described in Patent Document 1, the zirconium silicide contained in the core part absorbs infrared rays, so that the woven or knitted fabric exhibits a heat retaining effect. However, since this conjugate fiber has a concentric core-sheath structure, the surface area of the core portion containing zirconium silicide is small, and as a result, the infrared absorption efficiency is poor, and the woven or knitted fabric using the conjugate fiber is satisfactory. There is a problem that the thermal insulation effect of the level cannot be exhibited. In addition, the woven or knitted fabric has a problem that it is difficult to dye white or light due to the color emitted by zirconium silicide.

  On the other hand, the composite fiber described in Patent Document 2 has a plurality of protrusions in the cross-sectional shape of the core part, and has a large surface area of the core part, so that the infrared absorption efficiency is good, and the woven or knitted fabric exhibits a corresponding heat retaining effect. . However, in such a composite fiber, it is necessary to increase the cross-sectional area of the nozzle hole during spinning in order to cope with a complicated cross-sectional shape of the core part. If it does so, the discharge distribution of the polymer which comprises a core part will not become uniform, but as a result, when a woven or knitted fabric is dye | stained, there exists a problem that a staining spot tends to generate | occur | produce.

  The present invention eliminates the disadvantages of the prior art described above, and is composed of a composite fiber that includes a specific component and has a specific structure, and has a good spinnability and an excellent heat retaining effect using this yarn. At the same time, it is a technical problem to provide a woven or knitted fabric that can be dyed in white and light colors and has few dyed spots.

  As a result of intensive studies to solve the above problems, the present inventors have made the present invention.

  That is, in the present invention, first, the sheath part is composed of the polyester polymer A containing 0.01 to 0.3% by mass of the fluorescent brightening agent, and the core part is 5 to 25 mass of the metal oxide infrared absorber. % Of the polyester polymer B contained in the composition, the mass ratio (A / B) of both polyester polymers is 90/10 to 40/60, and the cross section of the fiber has a flatness of 2.0 to 6.0 The core-sheath composite fiber yarn is characterized in that the joint shape of both polyester polymers is composed of a composite fiber having a shape along the contour of the outer periphery of the fiber.

  And secondly, a woven or knitted fabric using the core-sheath composite fiber yarn and having an absorption rate of 15% or more in an infrared region of a wavelength of 700 to 2000 nm, preferably having a fluorescent whiteness (WI) of 90 or more. The gist is woven or knitted.

  Since the core-sheath composite fiber yarn of the present invention is excellent in the infrared ray absorbing effect, it exhibits excellent heat retaining properties when made into a woven or knitted fabric. Further, the obtained woven or knitted fabric can be dyed in white or light color and has few dyeing spots, and thus is suitable for clothing use.

It is a cross-sectional schematic diagram which shows one embodiment of the composite fiber used for this invention.

  Hereinafter, the present invention will be described in detail.

  FIG. 1 is a schematic cross-sectional view showing one embodiment of the conjugate fiber used in the present invention. The yarn of the present invention is composed of fibers as shown in this figure, for example. Such a composite fiber is composed of two kinds of polyester polymers A and B and has a special core-sheath structure.

  The polyester composition in A and B is not particularly limited as long as it is a polyester capable of forming a fiber, and for example, polyethylene terephthalate, polybutylene terephthalate, and the like can be employed. Further, if necessary, a predetermined component may be copolymerized therewith to obtain a copolyester. When the copolymerized polyester is employed, examples of the copolymer component to be used include isophthalic acid, 5-alkaliisophthalic acid, aromatic dicarboxylic acids such as 3,3′-diphenyldicarboxylic acid, adipic acid, sebacic acid, and succinic acid. And aliphatic dicarboxylic acids such as diethylene glycol, 1,4 butanediol, 1,4 cyclohexanediol and the like, alicyclic diols, P-hydroxybenzoic acid and the like.

  Further, each polymer may contain an additive, a matting agent, an antistatic agent, an antioxidant and the like as long as the effects of the present invention are not impaired.

  In the composite fiber in the present invention, the sheath portion is composed of the polymer A. And in polymer A, it is necessary to contain 0.01-0.3 mass% of fluorescent whitening agents, Preferably 0.05-0.2 mass% is contained. When the content of the fluorescent brightening agent is less than 0.01% by mass, the color development of the fiber due to the metal oxide infrared absorber described later cannot be suppressed, and a sufficient whitening effect is given to the woven or knitted fabric. Can not be. On the other hand, if it exceeds 0.3% by mass, the fiber undergoes a concentration quenching phenomenon, resulting in an increase in yellowishness to the fiber, and it becomes impossible to give a sufficient whitening effect to the woven or knitted fabric. In addition, it is preferable that the fluorescent whitening agent has the maximum fluorescence intensity in a wavelength region of 420 to 460 nm.

  Examples of the optical brightener used in the present invention include 2,5-bis (5′-t-butylbenzooxolyl (2)) thiophene (“Ubitex OB (trade name)” manufactured by Ciba Geigy), 4,4′-bis (2-benzoxazolyl) stilbene (“OB-1 (trade name)” manufactured by Eastman Chemical Co., Ltd.) and the like are mentioned, among which 4,4′-bis (2-benzoxazolyl) stilbene is preferable.

  On the other hand, the core of the composite fiber is made of polymer B. And in the polymer B, it is necessary to contain 5-25 mass% of metal oxide infrared absorbers, Preferably it is contained 7-17 mass%. When the content of the infrared absorber is less than 5% by mass, the fiber does not exhibit a sufficient infrared absorption effect, and a sufficient heat retaining effect cannot be given to the woven or knitted fabric. On the other hand, if it exceeds 25% by mass, the flexibility of the fiber disappears and the fiber becomes brittle, and the spinnability and processability of the yarn are significantly lowered.

Examples of the infrared absorber used in the present invention include antimony-doped tin oxide, tin-doped indium oxide, a mixture of titanium oxide and tin oxide, and the like. Also, the mass ratio of the polymers A and B in the composite fiber (A / B) needs to be 90/10 to 40/60, preferably 80/20 to 50/50. When the ratio of the polymer A exceeds 90% by mass, the ratio of the core portion in the fiber becomes low, and a sufficient infrared absorption effect cannot be obtained in the fiber. On the other hand, when the ratio of the polymer A is less than 40% by mass, a sufficient infrared absorption effect can be obtained, but the polymer B is easily exposed on the fiber surface, and the joining shape of both polymers can be made to conform to the outer periphery of the fiber. As a result, the flexibility of the fiber disappears and the fiber becomes brittle, and the spinnability and workability of the yarn are significantly reduced.

  Furthermore, the composite fiber in the present invention is also characterized in the structure.

  First, in the composite fiber, the fiber cross section needs to have a flat cross-sectional shape. The flatness at that time needs to be 2.0 to 6.0, preferably 3.0 to 5.0.

  If the fiber cross section of the fiber is a flat cross section, the gap between the fiber bundles is filled with protrusions when the fibers are bundled, so that a yarn having a high fiber density can be obtained. As a result, since the amount of transmitted infrared rays is reduced when a woven or knitted fabric is obtained, the infrared absorbing effect is improved as a whole woven or knitted fabric. This effect is remarkable as compared with the case of the round cross-section fiber.

  The flatness is a value obtained by dividing the length of the longest line segment (L1) passing through the center of the fiber cross section by the length of the line segment (L2) orthogonal to L1 and passing through the center part (L1). / L2) (see FIG. 1).

  When the flatness is less than 3.0, the gap between the fiber bundles cannot be filled, and a yarn having a high fiber density cannot be obtained. On the other hand, if it exceeds 6.0, the spinnability and workability of the yarn are lowered.

  Moreover, in the composite fiber in this invention, the joining shape of the polymers A and B has comprised the shape along the outline of fiber outer periphery. By adopting such a shape, it is possible to prevent the polymer B from being exposed to the fiber surface. Conventionally, a core-sheath composite fiber having a round cross section in the core and an irregular cross section throughout the fiber has a problem in that the polymer constituting the core is easily exposed on the fiber surface, and the spinnability and workability of the yarn have been problematic. In the present invention, this problem can be solved by adopting such a structure.

  Here, an example is described about the manufacturing method of a core sheath composite fiber yarn. The yarn of the present invention was melt-spun by a POY method for obtaining a semi-undrawn yarn by high-speed spinning at a spinning speed of 2000 m / min or higher, low-speed spinning at less than 2000 m / min or high-speed spinning at 2000 m / min or higher, and then wound up Thereafter, it can be obtained by a method of drawing and heat-treating the yarn, a direct spinning drawing method of drawing continuously without winding once.

  In addition, polymers A and B can be prepared by adding a fluorescent whitening agent to A and an infrared absorber to B in the polymerization step of the polyester polymer as a base, Examples thereof include a method in which a whitening agent is added to B and an infrared absorbing agent is added thereto, and melt kneading is performed. However, the addition of the fluorescent whitening agent and the infrared absorber in the polymerization stage may cause the aggregation of the fluorescent whitening agent and the infrared absorber and the deterioration of the spinnability. Therefore, the melt-kneading method is preferable in the subsequent step.

  Next, the woven or knitted fabric of the present invention will be described.

  The woven or knitted fabric of the present invention is a woven or knitted fabric using the core-sheath composite fiber yarn. In such a woven or knitted fabric, it is preferable to satisfy an absorption rate of 15% or more in an infrared region having a wavelength of 700 to 2000 nm. Thereby, since the outstanding infrared absorption effect can be show | played, the desired heat retention effect can be anticipated.

  In the woven or knitted fabric, the fluorescent whiteness (WI) is preferably 90 or more. As a result, a woven or knitted fabric having excellent whiteness is obtained, and white and light colors can be used.

EXAMPLES Next, although an Example demonstrates this invention concretely, this invention is not limited to these Examples.
(Example)
Intrinsic viscosity (measured at a temperature of 20 ° C. using a mixture of equal amounts of phenol and ethane tetrachloride as a solvent) 0.68 polyethylene terephthalate and 4,4′-bis (2-benzoxazolyl) stilbene as an optical brightener Polymer A was obtained by melt-kneading 1 mass%, chipping by a conventional method, and drying. On the other hand, polymer B was obtained by melting and kneading 10% by mass of antimony-doped tin oxide as an infrared absorber in polyethylene terephthalate having an intrinsic viscosity of 0.73, forming chips by a conventional method, and drying. Then, the polymers A and B are introduced into the core-sheath composite spinning apparatus, and melt-spun under the conditions of a spinning speed of 3500 m / min, a spinning temperature of 290 ° C., and a discharge amount of 43 g / min. An 80/20 semi-undrawn yarn was obtained. Subsequently, the semi-undrawn yarn was drawn at a draw ratio of 1.50 to obtain a drawn yarn having a flatness of 4.0 at 84 dtex / 48f. The spinning property was good in collecting the yarn.

  Moreover, when the cross section of the composite fiber which comprises a drawn yarn was observed using the electron microscope, it has confirmed that the joining shape of both polymers had comprised the shape along the outline of fiber outer periphery.

  The resulting core-sheath composite fiber yarn is used to form a tubular knitted fabric, and Bayer's dye “Terasil Navy Blue SGL (trade name)” is used at a bath ratio of 1:50 at 99 with a bath ratio of 1:50. When the tubular knitted fabric was dyed under the condition of 60 minutes at ℃ and the stained spots on the tubular knitted fabric were visually evaluated, almost no stained spots were observed.

  Furthermore, when the absorbance and transmittance of the above-mentioned tubular knitted fabric with a wavelength of 700 to 2000 nm were measured using a self-recording spectrophotometer “UV-3100 (trade name)” manufactured by Shimadzu Corporation, the absorbance was 19%, and the transmittance was 19%. The rate was 33%.

  Then, using a spectrophotometer “CM-3700D (trade name)” manufactured by Konica Minolta, fluorescent whiteness (WI) of the knitted fabric under the condition of UV = 99.9% according to the ASTM-E-313 method. Was measured to be 112.

(Comparative Example 1)
The same procedure as in Example 1 was conducted except that the flatness was changed to 4.0 instead of 4.0, but the spinnability and workability of the yarn were significantly lowered, and the yarn could not be collected. This is because the flatness of the fiber is too high.

(Comparative Example 2)
A drawn yarn was obtained in the same manner as in Example except that a concentric core-sheath structure was adopted as the structure of the composite fiber. In the obtained drawn yarn, it was confirmed that the joint shape of both polymers was a shape along the contour of the outer periphery of the fiber, similar to the composite fiber in the example.

  And when the dyeing spots of the tubular knitted fabric were evaluated in the same manner as in the example, almost no dyeing spots were observed. Further, when the absorptivity, transmittance and fluorescent whiteness (WI) of the knitted fabric were measured in the same manner as in the Examples, they were 9%, 56% and 109, respectively.

  When the knitted fabric in Comparative Example 2 and the knitted fabric in the example were compared, there was not much difference in the fluorescent whiteness, but a significant difference was observed in the infrared absorption effect. This is because the fibers had a concentric core-sheath structure, so that the surface area of the core portion was small and a sufficient infrared absorption effect could not be given to the knitted fabric.

A: Polyester polymer A
B: Polyester polymer B

Claims (3)

  The sheath part is composed of polyester polymer A containing 0.01 to 0.3% by weight of the optical brightener, and the core part is composed of polyester polymer B containing 5 to 25% by weight of the metal oxide infrared absorber, The mass ratio (A / B) of both polyester polymers is 90/10 to 40/60, and the fiber cross section has a flat cross-sectional shape with a flatness of 2.0 to 6.0, and the joint shape of both polyester polymers is A core-sheath composite fiber yarn comprising a composite fiber having a shape along the contour of the outer periphery of the fiber.   A woven or knitted fabric using the core-sheath composite fiber yarn according to claim 1, wherein the woven or knitted fabric has an absorptance of 15% or more in an infrared region having a wavelength of 700 to 2000 nm. A woven or knitted fabric using the core-sheath composite fiber yarn according to claim 1, having an absorptance of 15% or more in an infrared region of a wavelength of 700 to 2000 nm, and a fluorescent whiteness (WI) of 90 or more. A woven or knitted fabric characterized by being.