JPS61167045A - Fabric excellent in opacity - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Use Minute Hand) The present invention relates to a filament fabric that is difficult to see through and has excellent texture.

(Prior Art) Synthetic and IAM filament fabrics have been particularly developed for use in recent years, and have come to be widely used in everything from thin fabrics such as blouses to thick clothing such as slacks and coats. These advances have been made as a result of improvements in texture, nine colors, drapability, etc., while taking advantage of the easy-care properties of synthetic fibers.In particular, making them lighter and thinner is a direction that fully takes advantage of the characteristics of synthetic fibers.

However, the trend towards lighter weight and thinner fabrics also increases the transparency of woven and knitted fabrics, and in many cases, when wearing sewn products, items worn underneath can be seen through, impairing aesthetics. Ta.

Conventionally, synthetic filament woven and knitted fabrics are more transparent than natural fiber woven and knitted fabrics such as cotton, wool, and silk, with the same structure and date, making synthetic filament woven and knitted fabrics difficult to use in fields that require opacity. It was common. However, in fields where durability and functionality are strongly required, such as white or light-colored lab coats and sports clothing, there is a growing consumer need to switch from natural fibers to synthetic filament fabrics. Research into opacity is progressing, and 2.8 technology has already been developed.

One type is one in which fine inorganic powder such as titanium dioxide is dispersed in a resin binder and coated on the surface of the fabric, or a resin film with a different refractive index is formed on the surface of la pongee. Examples include those that have unevenness formed thereon. However, because of the applied resin layer, these have the disadvantage that the texture becomes rough and hard, the inorganic powder or coating falls off due to friction, and the effectiveness tends to decrease due to surface smoothing, so they are not widely accepted by consumers. It's not something you can do.

In addition, a technology using a sea-island type composite fiber made of two types of components with different average refractive indexes has been published to make the fiber itself opaque (Japanese Patent Publication No. 8814/1983).
. Although this method does not have the disadvantages of the post-processing method described above, it does impose certain restrictions on the components used, and it requires unnecessarily complicated manufacturing equipment because it is difficult to suppress the influence of light reflected on the fiber surface. It is hard to say that it is an economical method.

(Problems to be Solved by the Invention) In view of this situation, the inventors of the present invention have designed a thick edge and devised a weaving process, regardless of the post-processing method, so as not to impair the original texture and characteristics of the fiber. The present invention was arrived at as a result of intensive research aimed at obtaining synthetic filament fabrics with permanent opacity comparable to natural fiber fabrics using an industrially advantageous method.

(Means for Solving the Problems) The present invention provides fibrillated composite filaments in which 28I fiber-forming synthetic polymers with poor mutual affinity are continuously joined over the entire length of 1iAS.
~5 denier flattened filament 3 with oblateness of 1.8 or more
Contains at least 20% by weight of a mixed multifilament consisting of ~10 filaments and 1 to 4 multifilaments of 0.3 to 8 deniers and a degree of irregularity of 2.0 or more, and the multifilament has a Coverage rate of 40% or more, basis weight 400 f/Ml or less, thickness 0.81111
A woven fabric having excellent opacity and having a light transmission index that satisfies the following formula.

DXT≦6 (however, DXT (II/GO), T: light transmission index).

The present invention will be explained in detail below.

With this invention! A fibrillated composite filament consisting of two types of fiber-forming synthetic linear polymers with low mutual affinity is
It is desirable to have a cross section in which one component is joined to another component without completely surrounding it, and to give a specific example, two components as shown in Figure 2 (a) are joined side by side. A cross section in which a radial-shaped component and another component in a shape that complements the radial part are joined, as shown in Fig. 2 et al.), to), A component with a radial shape as shown in FIG. 2(d) complements the radiation part, and another component with a V-shaped recess facing toward the center and a V-shaped component that complements the recess. Those with a transverse cross section in which the components are joined and Fig. 2 (
As shown in θ), a comb-shaped component and a complementary component can also have a combined cross section. Among these composite filaments, those having radial-shaped segments in the cross section as shown in FIGS. 2(a) to (ω) are preferable because filaments with a uniform cross-sectional shape can be stably obtained during composite spinning.

What is important here is that these fibrillated composite filaments are composited to have a cross-sectional shape that is specific to the fibrillar structure. That is, fibril filaments (
4) Oblateness is 1.8 or more, fineness is 0°05-5 denier,
Flat filaments and fibril filaments (3 to 10 filaments) are composite-spun in advance to form multi-lobed filaments with a degree of irregularity of 2.0 or more, 9 m degrees, 0.3 to 8 deniers, and a multilobed cross-section of 1 to 4 filaments. It's about being there.

First, the flat filament will be explained. Fiber oblateness generally refers to the ratio (L//) of the major axis length to the minor axis length (L//) in the cross section of the fiber. As shown in FIG. 3 (roll), objects that are determined to be flat at first glance may be indicated in the figure or expressed by the numerical value of l. However, if the ribbon-like item is curved, or has a multi-sided shape with approximately 4 sides or less, or
In the case of a polygonal shape within a corner, as shown in FIG. 3(b), the longest length at the time of projection is defined as fi, and the shorter length fi is defined as l. The flatness of the flat filament used in the present invention is
According to the above definition, it needs to be 1.8 or more. This is to increase the reflection of light on the flat surface, and if the reflection of light is large, the light that enters into the fabric will naturally be suppressed, and furthermore, as the fibers repeat the reflection between each other within the fabric, it will naturally attenuate and go out of the fabric. The amount of light leaking can be reduced to a level that does not cause any problems. If the oblateness is less than 1.8, the oblateness is comparable to that of a triangular cross-section yarn obtained by ordinary spinning or a round cross-sectional yarn deformed by high-temperature false twisting, and only the opacity of the fabric obtained by conventional techniques can be obtained. , 1.8 or more is required. In order to further increase the effect, it is preferable that the aspect ratio is 1.6 or more.
In addition, at least one straight and smooth side in the cross section of the fiber,
Preferably, a shape having two sides is more desirable.

However, the edges were not smooth and unevenness increased due to false twisting.
Even if it is only one side, the purpose can be achieved if the aspect ratio is sufficiently large.

The fineness of the obtained flat filament must be in the range of 0.05 to 6 deniers, preferably 0.2 to 2 deniers. If it is less than 0.06 denier, it is undesirable because it is too small and may be buried among other multi-lobed cross-section filaments or deteriorate the wrinkle resistance of the fabric. On the other hand, if it exceeds 5 denier, the texture becomes rough and hard, which is not preferable. spinnability,
Considering the ease of handling the thread and the texture of the fabric, it is 0.
．． A range of 2 to 2 deniers is more preferable.

It is necessary that the flat filament after fibrillation be divided into 3 to 10 pieces per composite filament. This is to increase the reflection of light as much as possible, and if there are less than 2, it will be insufficient, and if there are more than 11, the spinning device will become complicated, the spinning performance will deteriorate, and the economic benefits will be lost.

Note that it is effective if the fiber diameter (2) before fibrillation and the long axis length (2) after fibrillation have a relationship of D/L = 1 to 2.5. This is to maintain an effective diameter that prevents light transmission even after fibrillation.

Next, a multi-lobed cross-section filament will be explained.

Here, a multilobal cross section refers to a shape in which the ridge line connecting adjacent vertices in the cross section of the fiber is delicately curved toward the center or is almost straight, as if forming two or more protrusions, or The degree of irregularity is defined as the ratio (R/r) of the radius of the inscribed circle (g) to the radius of the circumscribed circle (6) in the fiber cross section. In each of Figures 2 (translation) to (e), the B component ranges from a relatively simple four-lobed shape to a complex cross, star, and V.
They form a letter shape and a comb shape, but if we want to express the degree of irregularity as shown in FIG. 4, it is necessary for all of them to have a degree of irregularity of ξ of 2.0 or more. This is because the reflection of light is multiplied on the leaf surface of the multi-lobed cross-section filament, and when the reflection of light is large, the penetration of light into the fabric is suppressed, and as the multiple reflections within the fabric are repeated, the This is to reduce the amount of light that attenuates and leaks out of the fabric.

If the degree of irregularity is less than 2.0, it is no different from a normal trilobal cross-section yarn and has no meaning. In order to further increase the effect, the degree of irregularity is preferably 4.0 or more, and the cross section of the pongee is multilobed, which not only allows for a large degree of irregularity but also causes multiple reflections between the plurality of 11 surfaces within a single filament. Particularly preferred are those having similar structures.

The fineness of the resulting multi-lobed cross-sectional filament must be in the range of 0.3 to 8 deniers, preferably 0.5 to 6 deniers. If the thickness is less than 0.8 denier, the cross-sectional leaf portion will easily deform and it will be difficult to maintain an effective shielding effect, which is not preferable. On the other hand, if it exceeds 8 denier, the texture becomes rough and hard. Considering aspects such as spinnability, ease of handling the yarn, and texture of the fabric, it is more preferable that the denier is in the range of 0.6 to 6 denier.

Further, it is necessary that the multi-lobed cross-sectional filament after fibrillation be divided into 1 to 4 filaments per composite filament. If there are six or more fibers, the spinning device becomes complicated, which is not economical, and the texture is too soft, which is a disadvantage.

The important factors are the fiber diameter before fibrillation (2) and the radius of the circumscribed circle after fibrillation (2) Point = 1.5
It is effective if it is within the range of ~8. This is to maintain an effective shielding diameter that prevents light transmission even after fibrillation.

Furthermore, the relationship between the long sleeve length of the flat filament after fibrillation and the radius of the circumscribed circle (6) as 2R≧L is also effective for blocking light transmission. this is,
This is a condition for causing multiple reflections of light as much as possible within the fibril filament.

Here, the difference between M1 flat filament and multilobal filament will be explained. The flat filament has 2 to 8 light reflecting surfaces, and since the effective reflection direction is directional, they must be arranged in various directions within the cross section of the fabric. For example, if you apply shimmy calendering and line up the flat surfaces on the surface of the fabric, it will have a concealing effect, but it will also have disadvantages such as glare on the surface, so it is desirable that the flat surfaces be arranged randomly, and it is also recommended to do so. This contributes to improving the texture. On the other hand, multi-lobed filaments do not have any particular directionality in blocking light transmission, so they can be arranged in any direction and provide a great shielding effect. Compared to simple round cross-section threads of the same fineness, the bending and ribs have greater rigidity, so even after fibrillation, they have the role of maintaining the texture, tension, and stiffness of the fabric, and the inside of the fabric cross-section. It is particularly preferable to arrange

In the present invention, the polymers forming the fibrillated composite filament may be any combination of m, m-forming synthetic linear polymers with low mutual affinity, but include polyamides, polyesters, and polyolefins. It is desirable that the combination of the two types be more selected. The polyamides mentioned here include aliphatic polyamides such as nylon 6, nylon 66, and nylon 610, and aromatic polyamides such as polyxylylene adipamide and polyhexamethylene tutalamide.
Polyethylene terephthalate, polyethylene isophthalate, copolymerized polyethylene terephthalate, polybutylene terephthalate, etc., and polyolefins include polyethylene, polypropylene, polybutene-1, etc., but there are few problems in processes such as composite spinning and stretching, and there are no problems during false twisting. The most desirable combination is polyamide and polyester, which are easily fibrillated and have good dyeability.

The am-forming polymer used may also contain various additives, especially inorganic and organic powders such as matting agents, pigments, dyes, lubricants, crystal nucleating agents, and catalysts. Surprisingly, in the case of the special composite filaments used, there is no particular need for matting agents for opacification, as is usually assumed. Therefore, the fabric obtained according to the present invention is truly revolutionary in that it can prevent the fabric from becoming see-through while maintaining a clear feel without being dulled by the dulling agent. This is due to the advantage of a mechanism that performs reflection and absorption by utilizing the multiple reflections of light on the surface of the fibril filament mentioned above. If clear color tone is not particularly required, but opacity is strictly required, a matting agent may be used as necessary.

In the present invention, when weaving, the fibrillated composite filament may be used in the most appropriate form taking into consideration the structure, finishing agent, etc. For example, when the fabric structure has a single layer structure such as plain weave or twill weave, the effect is very good if only the filament is used for the warp and weft, but it can be mixed with ordinary yarn, used as a mixed yarn by plying, or mixed with ordinary yarn. You can also reach your goal by Furthermore, in the case of a multilayer structure such as a double layer, it is not necessary to use only the filament, and sufficient effects can be achieved by simply using it as the constituent yarn on the front or back side. Similarly, it is also effective to weave the fibers with ordinary yarns on the front or back weave, and it is also possible to use them by pre-mixing them with ordinary yarns or twisting them together. When mixed with other yarns, natural fibers such as cotton, wool, and silk, and spun yarns made from short fibers such as polyester, nylon, and polyacrylonitrile may be used in combination.

In the present invention, the fibrillated composite filament is
Part or all of the joint surfaces between the polymers in the two columns may be peeled off before weaving. If it has not peeled off at all, special physical and/or chemical peeling treatment is required at the fabric processing stage, and if it has completely peeled off in advance, knitting/weaving is required to prepare the fibrillated filaments. Since this may impair the ease of spreading, it is advantageous to use a composite filament that has been partially peeled off beforehand. There are various methods for separating a portion in advance. For example, there are methods to locally apply mechanical beating, kneading, bending, swirling, etc., methods to physically apply heat shrinkage, methods to chemically apply a swelling agent to one component, etc., but industrially, Fluid treatment or false twisting is advantageous in order to increase coverage and improve hand by crimp, and false twisting is particularly preferred. Further, the false-twisting method is generally classified into spindle false-twisting and friction false-twisting, but belt-type or disk-type friction false-twisting is suitable for the purpose of the present invention. This is because the cross-sectional deformation imparted to the false-twisted yarn by mechanical and thermal forces during false-twisting is smaller in the friction false-twisting method, and when spinning the composite yarn, it is possible to spin the yarn into a shape designed for the purpose of the present invention. This is because it is easy to maintain the shape.

After weaving, if the composite filaments are hardly exfoliated or only partially exfoliated, a physical or chemical exfoliation treatment is required at any stage of fabric processing. For this purpose, the entire fabric is usually subjected to mechanical beating;
There are methods such as kneading and bending, methods of physically applying #ζ heat shrinkage, and methods of chemically applying a drug that has a swelling or shrinking effect to one component. In some cases, two or more methods may be used in combination. . The most preferred is an emulsion or solution of a swelling agent for nylon such as benzyl alcohol.
Take appropriate timing after soaking the fabric in
This method involves applying heat at 0°C to open the fibers.

Fabric density can be controlled by selecting conditions such as concentration of emulsion, soaking time, temperature, etc.

Regardless of whether opening and peeling is performed before or after weaving, it is necessary that the flat filaments and multilobed filaments after fibrillation are sufficiently peeled from each other and are sufficiently far away from their original positions. By having a sufficient spread compared to the fibril diameter, the coating diameter can easily be several times or more, and by acting synergistically with the multiple reflection effect, it exhibits extremely great hiding power.

In the present invention, it is necessary to arrange the fibrillated filaments in such a way that they occupy at least 20% by weight of the fabric structure and exhibit a coverage density of 40% or more on the fabric projection plane to make the multiple reflection phenomenon of light effective. .

In general, warp yarns have a higher implant density and contribute more to opacity than weft yarns, and warp yarns are easier to obtain dimensional stability and forms such as crimp within the fabric are more stable. , it is effective to use the filament for the warp. For example, if you use composite filaments for 50% of the warp and regular yarn for the remaining 60% of the warp and weft, the specific gravity of the composite filament is 26I! The composite filament accounts for over 50% in the projection plane. In addition, when used for the weft of a double-edged back weave, the usage ratio of the filament is about 22%, but the composite filament in the projection plane is 100%.
% coverage. It is difficult to show sufficient coverage when the usage ratio is within 20M% of the fabric structure.

The opaque fabric obtained by the present invention has a basis weight of 400f/
/Hereinafter, the thickness is 0.8n or less. Weight is 40097P
If it exceeds d, the clothes will become too heavy and the wearability will be hindered. Moreover, if the thickness exceeds 0.8 fi, it becomes a thick fabric and impairs the activity when worn, which is not preferable. Compared to ordinary synthetic filament fabrics, the opacity of the fabric obtained by the present invention is particularly remarkable when the fabric weight is 800F/R or less and the thickness is 0.65a or less.

Such a specific arrangement should be taken into consideration during weaving, but if sufficient consideration is not given during processing, the performance will deteriorate. During processing, the constituent polymers are subjected to tension/relaxation in the warp and/or weft direction and pressure/relaxation in the thickness direction multiple times. For nylon, it is necessary to perform appropriate shrinkage treatment using a material having a carrier effect such as benzyl alcohol.

Furthermore, during processing, it is possible to use an antistatic finishing agent, a water repellent finishing agent, and an oil repellent finishing agent. There is no problem in coating with resin liquid such as urethane or acrylic. A urethane-based or fluorine-based resin film may be laminated.

Furthermore, during processing, there is no problem in applying cloth raising, emery raising, etc. as long as it is within an appropriate range. Rather, moderate napping is generally preferable because it increases opacity. Fibril filaments are cut at the piloerection part,
5. Opaque feeling caused by excessive brushing will easily disappear.

The light transmission index of the obtained fabric was measured by the following method.

Generally speaking, the optical density of light transmitted through dyed fabric is determined by the Pinesu equation. Function related to spectral reflectance R! ? ′
(2) is known as a function relating to the ratio of the absorption coefficient to the scattering coefficient S of /8, and is expressed by the following equation.

It is possible to measure 8% of the dyed cloth with a self-recording spectrophotometer equipped with an R cam and calculate the value of NI/8 of the sample cloth using a conversion table.

The opacity (hiding degree) of the sample is determined by determining 8% of the sample cloth at a wavelength of 600 nm, obtaining the K/8 value, and calculating Δ using the following formula.
(K/8) is calculated and expressed as a light transmission index T.

T=Δ(K/8)=(K/8)B−(K/8)
wHere, (K/8)B and (K/8)w represent the wavelength s o o nm of the cloth surface when a black mount and a white mount are applied to the back of the sample, respectively. Therefore, the smaller the T value, the higher the opacity.

Generally, the light transmittance of textiles decreases as the basis weight increases. The light transmission index measured by the above measurement method is T, and the basis weight is D (g/z
&), the relationship of TXD>8 has been obtained for conventional filament fabrics for general clothing, whereas in the case of the fabric according to the present invention, the range showing opacity is TXD≦
It is necessary to have a relationship of 6. In order to keep it within such a specific range, conditions such as weaving density during weaving, presence or absence of twisting, presence or absence of glue, width adjustment during processing, pressing, false twisting conditions, etc. It is necessary to choose appropriately. If opacity is particularly required, the range is 'I'XD≦6.
, 'I'XD≦4 in the most severe case.

(Effects of the Invention) The woven fabric according to the present invention has a soft texture and is easy to wear, and its opacity remains the same after washing 80 times as before washing.

Example 1 The polymer component constituting the radiation part, which has a cross section as shown in FIG. semidal polyethylene terephthalate containing, and the ratio is nylon 6/polyethylene terephthalate =
False-twist 1/8 150d/28f multifilament at a temperature of 195@C.

The number of twists was 2400T/M"' and the spindle was false-twisted in the css direction. The false-twisted yarn was twisted in 8 directions with 150'1'/M twin yarns and used for the warp and weft to obtain a 2/2 twill weave. This fabric was owf with white fluorescent dye (Hoechst Co., Ltd. Hostalix JP)
After dyeing at 0.5% at 180°C for 960 minutes, it was treated with a conventional antistatic finish and set in a dry heat setting at 180°C.

The resulting fabric had a warp density of 69 threads/inch and a weft density of 69 threads/inch.
Book/inch, date 214f/d, thickness 0, 54 IN
It was sufficiently opaque and had an extremely soft texture even when used for white coats and slacks. It was confirmed that the fibers were fibrillated.

In this example, the flatness of the fibril flat filament is 1
．． 41, the fineness was 1.05 denier, and the degree of irregularity of the fibril multilobed filament was 5.8B, and the fineness was 1.16 denier. The usage ratio and coverage of the composite filament used was 100%. The light transmission index of the obtained fabric was 0.0168, and the product with the fabric weight was 8.4.

Comparative Example 1 A semi-dull polyethylene terephthalate yarn 150d/80f having a round cross section was heated at a temperature of 216°C and a number of twists of 2400T/
A 2/2 twill weave was obtained by false twisting at M and additional twisting at 150 T/M for both warp and weft. This woven fabric was dyed under the same conditions as in the example and evaluated as a woven fabric of the same density, and the sheerness was large and the texture was stiff.

The light transmission index of the fabric obtained in this case is 0.05, and the basis weight is 2.
05 f /77g', and the product of light transmission index and date was 10.25.

Example 2 The polymer component having a cross section as shown in FIG. 2(a) and constituting the radiation part is bright polyethylene terephthalate, and the polymer having a shape that complements the radiation part is bright nylon 6. The ratio of ethylene terephthalate/nylon = 2/1 is 100 d150 f filament, and the false twisting temperature is 190'' C1 and the number of twists is 2600 T.
After false twisting 1 inch of belt frix in 8 directions with /M, double yarns were twisted in the S direction with 200'L''/M and inserted into the weft of the fabric.At this time, the warp was a semi-round cross section of 75d/72f. Dull polyethylene terephthalate yarn was used, and the structure was plain weave.

This fabric was dyed and finished under the same conditions as in Example 1.

The resulting fabric had a warp density of 110 wood/inch and a weft density of 6.
8 filaments/inch, composite filament usage ratio 64.1
! 4:311%, coverage rate 100% and date 116f/1d
It had a Pl of 0.80, had softness and appropriate drape, and was sufficiently opaque.・Also, when the cross section of the fabric was observed under a microscope, it was confirmed that the composite filaments were sufficiently fibrillated.

In this example, the flatness of the fibril flat filament is 1
．． 80, the fineness is 0.18 denier, and the degree of irregularity of the fibril multilobed filaments is 5.88. The fineness was 1.16 denier. The light transmission index of the obtained fabric was 0.020
, the product with date was 2.62.

Example 8 The polymer component having a cross section as shown in FIG. 2(a) and constituting the radiating part is full-dull polyethylene terephthalate, and the polymer component having a shape that complements the radiating part is semi-dull nylon 66. In addition, an interlace blend yarn of 50d/25f multifilament with a capacity ratio of polyethylene terephthalate/nylon=2/1, semi-dull round cross-section polyethylene terephthalate yarn 80d/24f, and semi-dull triangular cross-section polyethylene terephthalate yarn 5.
0a/48f are alternately arranged in the warp, and semi-dull triangular cross-section polyethylene terephthalate yarn 50d/48 is used in the weft.
f was implanted to obtain a plain woven fabric. After soaking this fabric in a 10% benzyl alcohol emulsion solution for 10 minutes, Example 1
It was dyed and finished under the same conditions.

The resulting fabric had a warp density of 128 threads/inch and a weft thread density of 9.
8 filaments/inch, composite filament usage ratio 88% by weight! ! Date 801/d with E overturn rate of 62%.

It has a thickness of 0.22 nm, has excellent drapability and softness, and is made of 280 mm thick with normal high multifilament.
It is much more opaque and rare than real taffeta.

The fibril flat filament used in this example had an oblateness of 1.80 and a fineness of 0.18 denier, and the irregularity of the fibril multilobed filament was 6.88 and a fineness of 1.16.
It was denier. The light transmission index of the obtained fabric is 0.0
52, and the product with the date was 6.41.

[Brief explanation of the drawing]

No. 1 is an example of a cross-sectional photograph of the opaque fabric of the present invention. Figures 2 (8) to (e) are specific examples of cross sections of fibrillated composite filaments that can be used in the present invention;
A and B indicate a component to become a flat filament (5) and a component to become a multilobal cross-sectional filament CB), respectively. Figures 3(a) and 3(b) show how to measure the major axis and minor axis l used in the formula for the flatness of a flat filament in the present invention, and Figure 4 also shows how to measure the degree of irregularity of a multi-lobed filament. Inscribed circle radius (r) and circumscribed circle radius (2) used in the formula
This explains the measurement method of . 〃 Kanebo Gosen Co., Ltd. Figure 1 CαJ-11-

Claims (1)

[Scope of Claims] (1) A 0.05-5 denier fibrillated composite filament in which two types of fiber-forming synthetic polymers with poor mutual affinity are continuously joined over the entire length of the fiber. Contains at least 20% by weight of a mixed fiber multifilament consisting of 3 to 10 flat filaments with an oblateness of 1.3 or more and 1 to 4 multilobed cross-sectional filaments of 0.3 to 8 deniers and a nonuniformity of 2.0 or more. and the multifilament has a coverage of 40% or more on the projected surface of the fabric, has a basis weight of 400 g/m^2 or less, a thickness of 0.8 mm or less, and has a light transmission index that satisfies the following formula, and has excellent opacity. . D×T≦6 (however, D: area weight (g/m^2), T: light transmission index) (2
2.) The fabric according to claim 1, wherein the composite filament comprises a combination of two polymers with low mutual affinity selected from the group of polyester, polyamide, and polyolefin. (3) The fabric according to claim 1, having a cross section in which one component of the composite filament is joined without completely surrounding the other component. (4) Claim 3 having a cross section in which two components of the composite filament are repeatedly joined side-by-side.
Fabrics described in section. (5) The fabric according to claim 3, wherein the composite filament has a cross section in which a component having a radial shape and another component having a shape that complements the radiant portion are joined. (6) The woven fabric according to claim 1, wherein the composite filament is a false twisted yarn. (7) The fabric according to claim 1, wherein the composite filaments are subjected to friction false twisting.