JPH1143820A - Hollow conjugate fiber having cube type cross section - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a conjugate fiber, having cube type cross section, which is a heat-storage and heat-retaining fiber, improved in whiteness, having original gloss and improved in heat-retaining property. SOLUTION: This hollow fiber exhibits a cube type cross section shape having two projections 4 making nearly right angle in each corner of square part 5, whose cross section is square, having a hollow part 2 in the neighborhood of the center part. The square part 5 comprises a thermoplastic polymer containing zirconium carbide fine particles in an amount of 0.5-7.0 wt.% based on total fiber and the projection part 4 comprises a thermoplastic polymer and a ratio of an area of the projection 4 to whole area in the cross section of fiber is 130% and bulkiness ratio of fiber is >=20% and the luminosity is >=45.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention has a heat storage and heat insulation performance suitable for use in clothing and the like that requires heat insulation,
The present invention relates to a hollow composite fiber having a well-shaped cross section, which has a unique glossiness and can be made into a fabric having excellent whiteness.

[0002]

2. Description of the Related Art As a fiber suitable for cold-weather garments that require heat retention and for sports and leisure garments in the open air, fine particles of zirconium carbide and the like are blended, and a heat-storing fiber that absorbs sunlight has been developed. (Japanese Patent Publication No. 3-9202). This fiber has a core-sheath shape, and zirconium carbide fine particles and the like are blended in the core. However,
This fiber has a problem that it is difficult to use it for applications requiring whiteness because the color of the zirconium carbide fine particles in the core appears on the fiber surface and is colored.

[0003] To solve this problem,
Japanese Patent Application Laid-Open No. 3-51312 proposes a core-sheath heat-insulating fiber having a core portion made of a thermoplastic polymer containing fine particles of zirconium carbide and fine particles of titanium oxide coated with tin oxide and antimony oxide. Have been. By using a combination of zirconium carbide fine particles, and titanium oxide fine particles surface-coated with tin oxide and antimony oxide, the fibers do not lower the heat storage heat retention property even if the amount of the zirconium carbide fine particles is reduced, Since the zirconium fine particles are blended in the core, the coloring of the zirconium carbide is hidden by the sheath component, and whiteness can be improved. However, there was a problem that the whiteness of the fiber was not sufficiently improved.

Japanese Patent Application Laid-Open No. 2-269808 discloses that the core polymer contains fine particles of zirconium carbide and the sheath polymer is a fiber having a core-sheath structure not containing these particles. A part in which closed cells are formed has been proposed. This fiber is one in which incident light is irregularly reflected by closed cells in the core and whiteness is improved. However, the closed cells of the fiber are formed in the core, and the closed cells are small, so that the incident light is not sufficiently diffusely reflected. Therefore, there is a problem that the whiteness is improved to some extent but is not sufficient, and the fiber does not have a unique gloss.

[0005]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems and provides a fabric containing zirconium carbide fine particles, which has excellent heat storage and heat retention properties, has unique gloss, and has improved whiteness. An object of the present invention is to provide a hollow composite fiber having a well-shaped cross section that can be used.

[0006]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, have reached the present invention. That is, the present invention relates to a hollow fiber having a well-shaped cross-sectional shape having a square cross-sectional shape, and having two projections that form a substantially right angle at each corner of the rectangular portion having a hollow portion near the center. A thermoplastic polymer having a square portion containing 0.5 to 7.0% by weight of zirconium carbide fine particles in the whole fiber;
The protrusions are made of a thermoplastic polymer, the ratio of the area of the protrusions to the total area in the cross section of the fiber is 30% or more, the bulkiness of the fiber is 20% or more, and the brightness is 45 or more. The gist is a hollow composite fiber having a well-shaped cross section.

[0007] The bulkiness of the fiber in the present invention is defined as
It refers to the ratio of the area of the dead air portion formed by the hollow portion and the projection in the cross section. The measuring method is to attach a microphotographing device to a Nikon Microphoto S optical microscope and photograph the cross-sectional shape of the single yarn for six single yarns.
As shown in the schematic cross-sectional view of the hollow cross section composite fiber of the present invention in FIG. 3, the values of the area A and the area B are calculated and obtained as follows, and the average value of the six is obtained. Bulk (%) = [(Area A) / (Area A + Area B)] ×
100

The lightness (gloss) is a fineness of 60d / 16f
Of woven fabric (113 density / 2.54cm, density of 77 density / 2.
A plain fabric of 54 cm), eight such fabrics are superposed, and the L value is measured under the following conditions. Measuring machine: Shimadzu UV-3101PC Measurement wavelength: 380 to 780 nm Standard white plate: Barium sulfate Light source: D65

[0009]

Next, the present invention will be described in detail. As the thermoplastic polymer constituting the quadrangular portion and the protruding portion of the well-shaped hollow composite fiber of the present invention, nylon 6, nylon 11, nylon 12, nylon 46, nylon 66, nylon 610, etc., and those containing these as main components Examples include polyamide, polyethylene terephthalate, polybutylene terephthalate, and the like, and polyester, polyethylene, polypropylene, and the like containing these as main components, and polyolefin containing these as main components. The thermoplastic polymer in the square portion and the protrusion may be the same or different.

Next, the shape of the fiber of the present invention will be described with reference to the drawings. 1 and 2 are schematic cross-sectional views showing an embodiment of the well-shaped hollow composite fiber of the present invention. FIG.
The cross-sectional shape is quadrangular, and has a well-shaped cross-sectional shape having two substantially perpendicular projections 4 at each corner of a quadrangular portion 5 of a hollow fiber having a hollow portion 2 near the center. FIG. 2 shows a core-sheath shape in which a quadrangular portion 5 has a hollow portion 2 near a center portion, is composed of a core portion 1 and a sheath portion 3, and a quadrangular portion having a sheath portion 3 and a projection portion 4 formed of the same polymer. Is a hollow composite fiber having a well-shaped cross section.

In the thermoplastic polymer constituting the hollow composite fiber having a well-shaped cross section of the present invention, 0.5 to 7.0% by weight, preferably 0.1% by weight, of zirconium carbide fine particles is contained in the whole fiber.
7 to 5.0% by weight. That is, the shape shown in FIG. 1 has the square portion 5 and the shape shown in FIG. 2 has the core portion 1 of the square portion 5 made of a thermoplastic polymer containing fine particles of zirconium carbide. If the content of the zirconium carbide fine particles is less than 0.5% by weight, sufficient heat storage and heat retention cannot be provided. On the other hand, the content is 7.
If it exceeds 0% by weight, the effect of heat retention is saturated, the cost is increased, and the spinnability is deteriorated, and the fiber strength is liable to be reduced.

The fine particles of zirconium carbide used in the present invention preferably have an average particle size of 5 μm or less.
Further, the thickness is preferably 1 μm or less. If the average particle size exceeds 5 μm, clogging of the filter medium is likely to occur in the spinning process, and as a result, thread breakage tends to occur.

The hollow composite fiber having a well-shaped cross section according to the present invention has a projection area of 30% of the total cross-sectional area of the fiber.
That is, it is necessary that the bulk ratio of the fiber is 20% or more. Because the well-shaped hollow composite fiber of the present invention is a hollow fiber having a well-shaped cross-sectional shape having such projections,
Since the incident light from the outside is reflected by the projections, the coloring of the zirconium carbide fine particles in the square portion is concealed, whiteness is improved, unique gloss is exhibited, and a fiber having a brightness of 45 or more can be obtained. . Further, when the fabric is formed by knitting and weaving, at the same time bulkiness is imparted by the projections, a dead air portion is formed between the fibers, and the heat retention is improved.

Further, since the hollow portion 2 is formed, the hollow portion 2 also serves as a dead air portion, so that it is difficult to release the heat stored by the zirconium carbide fine particles, so that the heat retention is improved and the hollow portion 2 is formed. , The resulting fabric has excellent lightness.

In the present invention, as shown in FIG. 2, the quadrangular portion 5 has the hollow portion 2 and has a core-sheath configuration comprising the core portion 1 and the sheath portion 3 so that the core portion 1 contains the polymer in the polymer. The coloring of the zirconium carbide fine particles thus obtained is concealed by the sheath portion 3, and the whiteness can be further improved as compared with the fiber having the shape shown in FIG.

As shown in FIG. 2, when the square part 5 has a core-sheath composite form composed of the core part 1 and the sheath part 3, the sheath part and the projection part are made of a thermoplastic polymer, and the total area in the cross section of the fiber is Of these, the ratio of the area of the core is preferably 20 to 60%. If the ratio of the core portion 1 is less than 20%, the ratio of the zirconium carbide fine particles in the polymer of the core portion 1 becomes too large, so that the strength of the fiber is reduced or the fiber formability is likely to be deteriorated. When the ratio of the core portion 1 exceeds 60%, the ratio of the sheath portion becomes too small, and the effect of concealing the coloring of the core portion tends to be poor.

In the hollow composite fiber having a well-shaped cross section of the present invention shown in FIGS. 1 and 2, the ratio of the area of the projections 4 to the total area of the cross section of the fiber is 30% or more. The ratio of the area of the protrusion 4 is
If it is less than 30%, the proportion of the projections in the entire fiber becomes small, and it is not possible to sufficiently reflect the incident light from the outside, and the lightness does not become a fiber of 45 or more. Insulation cannot be imparted. The upper limit of the area ratio of the projection 4 is not particularly limited, but is preferably about 60%. If the area ratio exceeds 60%,
It is difficult to maintain the shape of the fiber.

Further, it is necessary that the bulk ratio of the fibers, which is the ratio of the area of the dead air portion between the fibers formed by the hollow portions and the projections in the sectional area, is 20% or more.
When the bulkiness is less than 20%, the number of dead air portions formed is too small, and the fabric obtained from these fibers has insufficient heat retention and poor lightness. The upper limit of the bulkiness is not particularly limited, but is preferably about 40%. If the bulk ratio exceeds 40%,
If the hollow portion is too large, the fiber tends to have hollow cracks. If the length of the protruding portion is too long, it is difficult to maintain the shape of the fiber, and the quality of the obtained fabric tends to deteriorate.

Further, the hollow composite fiber having a well-shaped cross section of the present invention must be a fiber having a lightness of 45 or more. This lightness is a value that is affected by the reflection of incident light by the protrusion, and if the content of zirconium carbide fine particles increases,
The value of this brightness decreases, and if the titanium oxide is contained in the polymer, the value of the brightness increases. The fiber of the present invention has a brightness of 45 or more, even when the projections and the quadrangular portion are made of a polymer containing no titanium oxide, and one of the projections and the quadrangular portion is made of a polymer containing titanium oxide. If it is, the brightness becomes 50 or more.

In the case of a core-sheath composite fiber having a round cross-sectional shape that does not contain titanium oxide and contains the content of the zirconium carbide fine particles specified in the present invention in the core, the value of this lightness is at most about 38. As in the case of the fiber of the present invention, the ratio of the protrusions is 30%.
As described above, a fiber having a well-shaped cross-sectional shape having a bulkiness of 20% or more can be a fiber having a brightness of 45 or more even when titanium oxide is not contained. And, by using fibers having a lightness of 45 or more, the resulting fabric is concealed from coloring by the zirconium carbide fine particles, has a unique glossiness and excellent whiteness, and also has excellent dyeability. Become.

In the case where titanium oxide is contained in the polymer of the quadrangular portion or the projection portion, in addition to the zirconium carbide fine particles, for example, it is known as white conductive fine particles as disclosed in Japanese Patent Publication No. 60-21553. And fine particles of titanium oxide coated on the surface with tin oxide and antimony oxide. By using the zirconium carbide fine particles and the coated titanium oxide fine particles in combination, even if the amount of the zirconium carbide fine particles is reduced, the heat storage and heat retaining property is not reduced, so that a fiber having improved whiteness can be obtained. Even when the zirconium carbide fine particles and the coated titanium oxide fine particles are used in combination, the content of the zirconium carbide fine particles should be at least 0.5% by weight, and the content of both should not exceed 7.0% by weight.

The hollow composite hollow fiber of the present invention can be produced by using a composite spinning apparatus in accordance with a conventional method of producing a composite fiber, and in order to produce it with high productivity, a high-speed melt spinning method is employed. It is desirable to do.

[0023]

The well-shaped cross-section hollow conjugate fiber of the present invention is excellent in heat storage and heat retention due to the inclusion of zirconium carbide fine particles,
Since the projections have the projections, the incident light from the outside is reflected by the projections, and the coloring of the zirconium carbide fine particles can be hidden. That is, since the ratio of the protrusion is a specific ratio and the fiber has a well-shaped cross-sectional shape with a bulk ratio of 20% or more, the incident light from the outside is well reflected by the protrusion, and the lightness of the fiber is reduced. It can be 45 or more, and it is possible to obtain a fabric having unique glossiness and excellent whiteness, and also having good dyeability. The dead air portion formed by the hollow portion and the dead air portion formed between the fibers by the protruding portion make it difficult for heat stored by the zirconium carbide fine particles to escape, and the resulting fabric has excellent heat retention and light weight. Is also excellent. Furthermore, by using a composite fiber having a core-sheath shape in which the square portion has a hollow portion, the effect of hiding the coloring of the zirconium carbide fine particles is improved, and a fiber having a higher brightness can be obtained. The feeling and whiteness can be improved.

[0024]

Next, the present invention will be described specifically with reference to examples. The cross-sectional shape of the fiber and the heat storage and heat retention were measured as follows, and the bulkiness and lightness of the fiber were evaluated by the methods described above. [Cross-sectional shape of fiber] A microphotographing device was attached to a Microphoto S optical microscope manufactured by Nikon Corporation, and the cross-sectional shape of the single yarn was photographed for six single yarns. Calculated and averaged. [Heat storage heat retention property] Using the obtained fiber as warp and weft, weave a plain woven fabric with a warp density of 113 strands / 2.54 cm and a weft density of 77 strands / 2.54 cm and 1.5 m in a constant temperature room at 20 ° C and 65% RH. The light was irradiated with light from a 500 W white light bulb from a distance of about 3 minutes, and about 3 minutes after the start of irradiation, the surface temperature on the opposite side was measured with a JEOL infrared sensor: Thermoviewer.

Examples 1-3, Comparative Examples 1-2 Relative viscosity (concentration 1 g / dl, 96% sulfuric acid as solvent, temperature 25
Measured in ° C. ) 96 parts by weight of 3.5 nylon 6 pellets and 4 parts by weight of fine particles of zirconium carbide having an average particle size of 0.7 µm were added and uniformly melt-mixed to obtain master pellets. Each of the master pellet (forming a square portion) and a nylon 6 pellet having a relative viscosity of 3.5 containing no zirconium carbide fine particles (forming a projection in the shape of FIG. 1 and a projection and a sheath in the shape of FIG. 2), respectively. Feeded to separate extruders. Then, it is introduced into a composite spinneret, spun at a spinning temperature of 275 ° C., stretched between rollers, wound up at a speed of 3500 m / min, and formed into a hollow composite having a well-shaped cross section as shown in FIGS. A fiber (60d / 16f) was obtained. At this time, the discharge amount and the draw ratio were changed to obtain fibers having a cross-sectional shape as shown in Table 1. Table 1 shows the ratio of the protrusions, the ratio of the cores, the bulkiness, the brightness, and the evaluation of the heat storage and heat retention of the fabric in the cross section of the obtained fiber.

Comparative Example 3 The same procedure as in Example 1 was carried out except that the core-sheath hollow conjugate fiber had a round cross section and had no projection. Table 1 shows the evaluation of the ratio of the core in the cross section, the bulkiness, the brightness, and the heat storage and heat retaining property of the fabric in the cross section of the obtained fiber.

Examples 4 and 5 A polymer forming a square portion was prepared by using nylon 6 pellets 94
4 parts by weight of zirconium carbide fine particles having an average particle diameter of 0.7 μm and 2 parts by weight of coated titanium oxide fine particles [white conductive fine particles W1 (cTiO ₂ ) manufactured by Mitsubishi Metals Corporation] having an average particle diameter of 0.2 μm. The procedure was performed in the same manner as in Example 1 except that the polymer forming the projections and the sheath contained 0.25% of ordinary titanium oxide. Table 1 shows the ratio of the protrusions, the ratio of the cores, the bulkiness, the brightness, and the evaluation of the heat storage and heat retention of the fabric in the cross section of the obtained fiber.

[0028]

[Table 1]

As is clear from Table 1, the conjugate fibers of Examples 1 to 5 were excellent in heat storage and heat retention, and could be made into a fabric having a unique glossiness and excellent whiteness. On the other hand, the fibers of Comparative Examples 1 and 2 did not sufficiently reflect incident light from the outside because the ratio of the protrusions in the cross-section was too small, and the lightness was not 45 or more. It was poor in unique glossiness and whiteness, and poor in heat storage and heat retention. Comparative Example 3 was a hollow core-sheath composite fiber having a round cross-section without any protrusions, and therefore had low brightness, and the resulting fabric did not have a unique glossiness and whiteness, and was a heat storage and heat insulating material. She was poor in sex.

[0030]

The hollow composite fiber having a well-shaped cross section according to the present invention, when knitted or woven, has excellent heat storage and heat retention properties, and at the same time, has a unique glossiness and excellent whiteness, and is excellent in dyeability. Obtainable.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view showing one embodiment of a well-shaped hollow composite fiber of the present invention.

FIG. 2 is a schematic cross-sectional view showing another embodiment of the well-shaped hollow composite fiber of the present invention.

FIG. 3 is a schematic cross-sectional view showing a method for calculating a bulkiness rate of a well-shaped hollow composite fiber according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Core part 2 Hollow part 3 Sheath part 4 Projection part 5 Square part

Claims (3)

[Claims] 1. A hollow fiber having a well-shaped cross-sectional shape having a quadrangular cross-sectional shape and having two substantially perpendicular projections at each corner of a quadrangular portion having a hollow portion near a center portion, The square part is a thermoplastic polymer containing 0.5 to 7.0% by weight of zirconium carbide fine particles in the whole fiber, and the protrusion part is a thermoplastic polymer, and the ratio of the area of the protrusion part to the whole area in the cross section of the fiber is 30% or more. A hollow composite fiber having a well-shaped cross section, wherein the bulkiness of the fiber is 20% or more and the lightness is 45 or more. 2. A square-shaped portion having a core-sheath shape having a hollow portion, wherein the core portion contains fine particles of zirconium carbide having a particle size of 0.5 to
The thermoplastic polymer containing 7.0% by weight, the sheath and the projection are made of a thermoplastic polymer, and the ratio of the area of the core to the total area in the cross section of the fiber is 20 to 60%.
The hollow composite fiber having a well-shaped cross section according to the above. 3. The hollow composite according to claim 1, wherein at least one of the thermoplastic polymer forming the quadrangular portion and the thermoplastic polymer forming the protrusion contains titanium oxide and has a brightness of 50 or more. fiber.