JPH08218247A - Opaque yarn aggregate - Google Patents

Abstract

PURPOSE: To obtain a yarn aggregate capable of forming opaque fabric suitable for sport clothing for leisure, having see-through preventing properties, by specifying the reflectance and the voids of an aggregate of multi-leaf type polyester- based yarn. CONSTITUTION: This aggregate of multi-leaf type polyester-based yarn has >=85% reflectance R at 500nm wavelength and 20-60% voids. The reflectance can be regulated by controlling the content of white-based pigment. Three to four leaves for providing the section of yarn with a deep uneven part preferably sets the degree of modification in the range of 0.05 to 0.80 in terms of multiple layer formation of air layer.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a fiber assembly having excellent opacity. Further, the woven or knitted fabric of the fiber aggregate relates to a fiber aggregate having a bulge, a good texture, and a lightweight woven or knitted fabric.

[0002]

2. Description of the Related Art Recent trends in needs for clothing require white and non-transparent materials, and demand for these materials for tennis wear and swimwear used for leisure sports and white coats used in the medical field. Is increasing. Synthetic fibers such as polyester and polyamide have a large single-filament fineness, a simple cross-sectional shape, and a uniform and simple internal structure on the surface. There was a problem that it was easy to see through when used.

Therefore, in order to improve the above-mentioned drawbacks of synthetic fibers, core-sheath type composite fibers in which inorganic fine particles having a high refractive index are contained only in the sheath portion, or the cross section of the synthetic fibers is modified The hollowing of fibers is widely used. However, it is difficult to obtain a fiber assembly that exhibits opacity even when it is wet with water or sweat, and that has properties such as lightness and sublime.

When the core portion of the core-sheath type composite fiber contains a high concentration of inorganic fine particles having a high refractive index, the color tone of the composite fiber becomes yellowish, and its application to white fabrics and light-colored products is restricted. It Also, in the case of a hollow and round cross section, the opacity is improved due to the difference in the refractive index due to the air layer, but problems such as hollow parts due to post-processing such as twisted yarn, crushing of the fiber cross section, etc., and the feeling of swelling etc. Is not enough. As described above, the conventional product has no fiber aggregate that can be applied to white fabrics and light-colored ones and is excellent in texture such as swelling.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to form a fabric which is excellent in anti-seepage property, has sublime, swelling, tensioning, good texture with elasticity, and is lightweight and opaque. To provide a possible fiber assembly.

[0006]

That is, the present invention provides a fiber assembly comprising multileaf polyester fibers,
A fiber assembly having a reflectance ΔR of 85% or more at a wavelength of 500 nm and a porosity of 20 to 60%.

Hereinafter, the present invention will be described in detail. The fiber assembly of the present invention is mainly composed of multi-leaf type polyester fibers and is characterized by having a specific reflectance and porosity.

The number of leaves of the multileaf polyester fiber according to the present invention is preferably 3 to 5 from the viewpoint of forming a deep uneven portion in the fiber cross section. The aggregate of such multileaf polyester fibers has a porosity of 20 to 60%,
It is preferably 20 to 40%. The porosity defined in the present invention is a value represented by the following formula by observing a cross section of a twisted yarn measured by a method described later with an optical microscope.

[0009]

[Equation 2] Porosity (%) = [(void weight) / (fiber weight + void weight)] × 100

By increasing the porosity between the fibers of the fiber assembly, the apparent thread diameter becomes thicker, the fiber assembly has a feeling of lightness and swelling, and the fiber assembly has a multi-layered air layer. By forming the opaque film, the reflectance is increased and the opacity is improved.

When the porosity is less than 20%, the fiber aggregate is not superior to conventional woven or knitted fabrics in terms of opacity, lightness and bulkiness. On the other hand, when the porosity exceeds 60%, weight reduction can be expected, but the fiber density becomes small, the transparency preventing property is insufficient, and the swelling feeling, tension, waist, etc. are also insufficient. The porosity specified in the present invention is a value measured by the method described below, and is a value calculated, and the fiber assembly of the present invention is not bound to the specified porosity and is suitable for the target fiber product. The porosity of a textile product (woven or knitted fabric) can be changed.

The cross-sectional shape of the multi-leaf type polyester fiber having the porosity as described above includes those having 3 to 5 leaves as shown in FIG. It is preferably in the range of 0.05 to 0.80 from the viewpoint that the air layer is made multi-layered and the opacity of the fiber is improved. The degree of irregularity is a value represented by the following formula.

[0013]

## EQU00003 ## Deformation degree = R / L However, in the fiber cross section, L is the length AB of the line connecting the adjacent tip portions A and B, and R is adjacent to the recess D located in the middle of the adjacent tip portions. The length CD of the perpendicular to the line connecting the matching tip portions A and B is shown.

If the degree of irregularity is less than 0.05, the unevenness of the fiber cross-sectional shape will be small, and the fiber density will be high in the case of a fiber aggregate, so that it is difficult to realize a multilayered air layer. . On the other hand, if the degree of irregularity exceeds 0.8, the unevenness of the cross-sectional shape of the fiber becomes large, and the fiber is easily damaged in the manufacturing process, which may cause a problem of fibrillation.

The fiber assembly of the present invention has a wavelength of 500 n.
A great feature is that the reflectance R at m is 85% or more. If the reflectance is less than 85%, the opacity becomes unsatisfactory, and a white or light-colored woven or knitted fabric cannot be obtained as a fiber assembly. The reflectance R of the fiber assembly suitable as a white or light woven or knitted fabric is 90% or more.

As a polyester fiber which constitutes such a fiber assembly having the above-mentioned specific reflectance,
Examples thereof include polyester fibers containing a specific amount of white pigment. The polyester fiber can be melt-spun by kneading various fine particles during the polymerization of polyester, and by including a white pigment having a high refractive index as the fine particles, the reflectance of the fiber surface is improved and the opacity is improved. It is possible to raise. The multileaf polyester fiber according to the present invention preferably contains 1 to 10% by weight, particularly 2 to 5% by weight of a white pigment having a refractive index of 1.8 or more. When the content of the white pigment is less than 1% by weight, the aggregate composed of the fibers has a reflectance of less than 85% at a wavelength of 500 nm, and the woven or knitted fabric necessarily composed of the fiber aggregate lacks opacity. It is easy to become a thing. On the other hand, when the content of the white pigment exceeds 10% by weight, the pigment may agglomerate in the polyester fiber, which may cause fluff in the spinning / drawing process and breakage of fibers.

It is preferable to use a white pigment having a refractive index of 1.8 or more. When the refractive index is less than 1.8, the polyester fiber has a refractive index of 1.57.
Since it is 5-1.643, the improvement of the refractive index due to the addition of the white pigment cannot be expected so much, and it is difficult to expect the increase of the reflectance. The upper limit of the refractive index of the white pigment is not particularly limited, but it is currently difficult to obtain a white pigment having a refractive index of more than 3. Such white pigments include, for example, titanium oxide, zinc oxide, lithopone,
Among them, titanium oxide is preferable from the viewpoints of high refractive index, kneading property into polymer and weather resistance. The particle size of the white pigment is not particularly limited, but it is preferable that the average particle size is 0.2 μm or more in view of kneading into polyester, melt spinnability, opacity and the like.

FIG. 1 shows an example of the cross-sectional shape of the multileaf polyester fiber according to the present invention. The multileaf polyester fiber according to the present invention may be, for example, a composite fiber composed of a thermoplastic polyester A containing a white pigment and a thermoplastic polyester B containing no white pigment, and contains a white pigment. The fiber may be made of only the thermoplastic polyester A. As described above, the thermoplastic polyester constituting the fiber may be one kind or two or more kinds of polyester, and the fiber aggregate may have a reflectance of 85% or more at a specific wavelength and a specific wavelength. Having porosity is important. For example, two types of polyester, namely the above polyester A
Either of the polyester B and the polyester B may form the leaf portion of the cross-sectional shape.
As shown in (d), it is preferable that the polyester A containing a white pigment constitutes the leaves a. The degree of polymerization of these polyesters is within the range used for general clothing, and may be within the range where fiber formation is possible. In addition,
To these polyesters, usual additives for fibers such as an ultraviolet absorber and an antioxidant may be added.

The thermoplastic polyester A containing a white pigment is preferably a polyester which can be easily kneaded with a white pigment and which can be melt-spun. Such polyesters include aromatic dicarboxylic acids such as terephthalic acid and isophthalic acid, dicarboxylic acid components such as aliphatic dicarboxylic acids such as azelaic acid and sebacic acid, and fats such as ethylene glycol, propylene glycol and 1,4-butanediol. Examples of the polyester include a group diol, an ethylene oxide adduct of bisphenol A or bisphenol S, and a diol component such as an alicyclic diol such as cyclohexanedimethanol. The dicarboxylic acid component and diol component of the polyester are each 1
You may have only one kind or use two or more kinds.

The thermoplastic polyester B used in combination with the thermoplastic polyester A has a composite form in which the thermoplastic polyester A containing a white pigment and the thermoplastic polyester A do not separate during spinning, stretching, post-processing and the like. It is preferable to select and combine those having good properties such as compatibility, laminating, and bondability so that they can be maintained. For example, a fiber aggregate having a target performance can be obtained by selecting from the dicarboxylic acid component and the diol component exemplified as the above-mentioned thermoplastic polyester A, performing composite spinning, and adopting appropriate drawing conditions. . The thermoplastic polyester A and the thermoplastic polyester B may be the same or different.

The white pigment may be kneaded into the polyester by adding it to a slurry of a diol component such as ethylene glycol before transesterification in the polyester polymerization step. You can also mix in.

Further, the fiber assembly comprising the multi-leaf type polyester fiber according to the present invention preferably has an opacity F represented by the following formula [I] of 85% or more. Especially in white fabrics and light colors, this opacity judgment is sensitive,
It can be judged more effectively.

[0023]

[Formula 4] F = (L ^* _B / L ^* _W ) × 100 [I] However, L ^* _B is the L ^* value when the fabric (fiber assembly) is overlaid on the black base material, and L ^* _W is the white base material. Shows a L ^* value when a cloth (fiber assembly) is overlaid, a black base material is a black plastic plate (L ^* value = 12), and a white base material is a standard white board (L ^* value = 100).

When the opacity F of the fiber assembly is less than 85%, the wearer's inner garment and the skin can be easily seen through the fabric when worn, especially in the case of a white background or a light color system. On the other hand, when the value of the opacity F is 85% or more, the sheer prevention effect is exhibited even on a thin white material.

The multi-leaf polyester fiber according to the present invention may be thick and thin yarn (fluffy yarn) obtained by partially drawing.

The "fiber" in the present invention means long fibers, short fibers such as staples, filament yarns, spun yarns,
"Fiber aggregate" means a blended yarn of the "fiber" with natural fibers, semi-synthetic fibers, other synthetic fibers, other processed yarn such as twisted yarn, entangled yarn and crimped yarn, and fibers and yarns of these A woven or knitted fabric, a nonwoven fabric, a final garment, a textile product such as a towel, etc. Further, the fibers constituting the fiber assembly of the present invention may be dyed with a dye such as a fluorescent whitening agent.

[0027]

EXAMPLES The present invention will now be specifically described with reference to examples, but the present invention is not limited thereto.
In addition, each physical property in an Example was measured by the following method. (1) Intrinsic viscosity of polyester [η] (dl / g) 0.25 g / dl of target polyester using an equal weight mixed solvent of phenol and tetrachloroethane,
It was calculated from the three reduced viscosities measured at a temperature of 30 ° C. for solutions of three concentrations of 0.5 g / dl and 1.0 g / dl.

(2) Porosity (%) of fiber assembly Three yarns are aligned and subjected to 2500 T / M undertwisting, 3 of them are combined, and S400T / M overtwisting twisted yarn is microtome. An optical micrograph of the cross section of the fiber cut with was taken. The photograph was enlarged and cut into fibers and voids, and the porosity was determined by the weight ratio. However, for a fiber having a hollow portion such as a hollow fiber, the hollow portion was also calculated as the porosity. Porosity (%) = [(weight of void) / (weight of fiber + weight of void)] × 100

(3) Deformity of fiber An optical micrograph of a fiber cross section was taken, and measured and calculated by the above method.

(4) Reflectance R (%) Taffeta fabrics having a warp density of 114 filaments / dimension and a weft density of 86 filaments / dimension were measured with a Hitachi spectrophotometer U-3400, and a wavelength of 500 nm was obtained from the reflection curve obtained. The reflectance at was calculated.

(5) Opacity (%) of fiber assembly Using multileaf polyester fibers having a single fineness of 2.2 denier for warp and weft, 114 warps / dimension, 86 wefts /
Dimension was prepared, L ^{* of} this knitted fabric was measured using a Hitachi spectrophotometer (U-3400 type), and calculated by the following formula. Opacity _{^{(%) = (L * B}} / L * W) × 100 L * B: when the piled fabric (fiber aggregate) to the black matrix L ^*
The value L ^* _W: when the piled fabric (fiber aggregate) in white matrix L ^*
value

Examples 1 to 3 terephthalic acid and ethylene glycol were used, and the average particle size was 0.3.
1% by Weight of Titanium Dioxide (Example 1), 3% by Weight
(Example 2) A predetermined amount of 5% by weight (Example 3) was added to a slurry tank, mixed, transferred to an esterification tank, and heated at 280 ° C. under a pressure of 2.5 Kg / cm ² for 2 hours. After the esterification reaction, an ethylene glycol solution of antimony trioxide was added as a catalyst, and the temperature was changed from 240 ° C to 2 ° C.
Gradually 0.1mm while heating to 80 ℃ over 45 minutes
Reduce the pressure to Hg, react, and make chips by a conventional method.
[Η] = 0.68 polyethylene terephthalate (PE
T) was obtained. Spin at 290 ° C with each PET,
It was drawn under normal drawing conditions to obtain a four-branched fiber having a cross-sectional shape of 50 denier / 24 filament as shown in FIG. Table 1 shows the degree of irregularity of each drawn yarn and the porosity of the aggregate of drawn yarns. Using each of the drawn yarns obtained above as a warp yarn and a weft yarn, a taffeta having a weaving density of 114 warp yarns / dimension and 86 weft yarns / dimension was woven. This raw taffeta is soda ash 2
g / l, Actinol R-100 (Matsumoto Yushi) 1 g /
The scouring was carried out by treating with 1 for 100 minutes at 100 ° C. Then, heat setting was performed at 180 ° C. with a pin tenter. Table 1 shows the reflectance ΔR and the opacity F of each woven fabric measured by the above method. Since the reflectance and the opacity are high, and the porosity is also high, the fiber assembly was also lightweight. Furthermore, when the opacity was measured, the black base material overlaid on any of the fabrics was almost invisible.

Example 4 Spinning was carried out in the same manner as in Example 1 except that the fiber cross-sectional shape was changed as shown in FIG. Table 1 shows the irregularity of the drawn yarn and the porosity of the drawn yarn aggregate. Using the obtained drawn yarn, a taffeta fabric was woven in the same manner as in Example 1 and subjected to treatments such as scouring and presetting under the same conditions. Table 1 shows the reflectance ΔR and the opacity F of the woven fabric measured by the above method. Even if the cross-sectional shape of the fiber was a trifurcation type, the reflectance and opacity were high, and the porosity was also high, so the fiber assembly was also lightweight. Further, when the opacity was measured, the black base material overlaid on the woven fabric was slightly seen through, but there was no practical problem.

Example 5 Spinning was performed in the same manner as in Example 1 except that the fiber cross-sectional shape was changed as shown in FIG. Table 1 shows the irregularity of the drawn yarn and the porosity of the drawn yarn aggregate. Using the obtained drawn yarn, a taffeta fabric was woven in the same manner as in Example 1 and subjected to treatments such as scouring and presetting under the same conditions. Table 1 shows the reflectance ΔR and the opacity F of the woven fabric measured by the above method. By changing the cross-sectional shape of the fiber to the five-branch type, the porosity was increased, and the reflectance and opacity were also high.
Furthermore, when measuring the opacity, the black substrate overlaid on the fabric did not show through.

Comparative Examples 1 to 3 In Example 1, 1% by weight of titanium dioxide (Comparative Example 1), 3% by weight (Comparative Example 2) and 5% by weight (Comparative Example 3) were added, and the fiber cross-sectional shape was round. Spinning and drawing were performed in the same manner except that the cross section was used. Table 1 shows the porosity of the aggregate of the drawn yarns.
Shown in The porosity was 11%, which was very small compared to the examples, and far from weight reduction.
Using each of the obtained drawn yarns, a taffeta fabric was woven in the same manner as in Example 1 and subjected to treatments such as scouring and presetting under the same conditions. Table 1 shows the reflectance ΔR and the opacity F of the woven fabric measured by the above method. Since the cross-sectional shape of the fiber is a round cross-section, the fiber surface becomes smooth, diffuse reflection of light is unlikely to occur on the fiber surface, and opacity was not satisfactory. Also, when measuring opacity,
For any of the fabrics, the overlapped black substrate was transparent, which was a practical problem.

Comparative Example 4 Spinning and drawing were carried out in the same manner as in Example 2, except that the fiber cross section was changed to a hollow cross section having a hollow ratio of 25%.
Table 1 shows the porosity of the aggregate of drawn yarns. The porosity was 35% because it was a hollow fiber. Using the obtained drawn yarn, a taffeta fabric was woven in the same manner as in Example 1 and subjected to treatments such as scouring and presetting under the same conditions. The reflectance ΔR and opacity F of the woven fabric measured by the method described above.
Is shown in Table 1. Since hollow fibers are used, weight reduction due to porosity is improved, but since the fiber surface is smooth, diffuse reflection of light is small, and when measuring opacity, the black layered on the fabric The base material was transparent and there was a practical problem.

Comparative Example 5 Spinning was carried out in the same manner as in Example 3, except that the fiber cross-sectional shape was changed to the shape of porous fiber (10 holes) having a hollowness of 50%.
It was stretched. Table 1 shows the porosity of the aggregate of drawn yarns. The porosity was 62% because it was a porous fiber. Using the obtained drawn yarn, a taffeta fabric was woven in the same manner as in Example 1 and subjected to treatments such as scouring and presetting under the same conditions.
Table 1 shows the reflectance ΔR and the opacity F of the woven fabric measured by the above method. Since porous fibers are used, weight reduction due to porosity is improved, and improvement in opacity due to the multi-layered air layer is recognized as compared with hollow fibers,
Since the fiber surface is smooth, the diffuse reflection of light is small, and when measuring the opacity, the black base material laminated on the woven fabric is seen through as compared with the woven fabrics obtained in the examples, and there is a practical problem. there were.

[0038]

[Table 1]

[0039]

EFFECTS OF THE INVENTION A fiber assembly composed of multileaf type polyester fibers has a high porosity and is therefore excellent in lightness and sublime, and also has a high reflectance, so that it is dyed with a white or light color dye. Even though it does not show through, it has excellent opacity.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of a cross-sectional shape of a multileaf polyester fiber according to the present invention.

[Explanation of symbols]

 a: leaf

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Claims (2)

[Claims] 1. A multi-leaf type polyester fiber having a reflectance R at a wavelength of 500 nm of 85% or more and a porosity of 20 to 60%. 2. The opacity F represented by the following formula [I] is 85.
% Or more, The fiber assembly according to claim 1. [Formula 1] F = (L ^* _B / L ^* _W ) × 100 [I] However, L ^* _B is the L ^* value when the fabric (fiber assembly) is overlaid on the black base material, and L ^* _W is the white base material. L ^* when fabric (fiber assembly) is layered on
Values, the black substrate shows a black plastic plate (L ^* value = 12), and the white substrate shows a standard white plate (L ^* value = 100).