JP2512392B2 - Method for producing woven fabric with excellent opacity - Google Patents

Description

TECHNICAL FIELD The present invention relates to a filament woven fabric which is hard to be transparent and has an excellent feeling. More specifically, the present invention relates to a woven fabric that contains filaments having a special cross-sectional shape in a certain ratio or more, and by appropriately arranging the special cross-section filaments in the fabric, it does not impair the feeling effect and is excellent in opacity. is there.

(Prior Art) Filament woven fabrics made of synthetic fibers have been widely used in recent years, and are widely used for thin woven fabrics such as blouses, to thick clothing such as slacks and coats. These are the texture, color,
The progress has been made as a result of improvements in drapability and the like, and in particular, the reduction in weight and thinning is the direction in which the characteristics of synthetic fibers are fully utilized. However, the direction of lighter weight and thinner fabric is also the direction of "facilitating the see-through of the fibrous knit, and when wearing the sewn product, there is a case where the item worn on the lower side can be seen through and the aesthetics are impaired. It's getting more and more.

Conventionally, synthetic fiber filament woven and knitted fabrics are easy to see through compared to natural fiber woven and knitted fabrics such as cotton, wool and silk with the same structure and the same weight, and in fields where opacity is required, it is difficult to use synthetic fiber filament woven and knitted fabrics. Was common. However, especially in fields such as white coats used in white or light colors, sports clothing and the like, where durability and functionality are strongly required, synthetic fiber filament fabrics are used because of the increasing consumer needs to change the material from natural fibers to synthetic fiber filament fabrics. Research on opacity has been advanced, and a few technologies have already been developed.

One of them is one in which an inorganic fine powder such as titanium dioxide is dispersed in a resin binder and the surface of the fabric is coated, or a resin film with a different refractive index is formed on the fiber surface. An example is one that has irregularities. However, these are the resin layers that are applied, so they have the drawbacks that the texture becomes rough and hard, the inorganic powder and coating fall off due to friction, and the effect tends to decline due to surface smoothing, which is widely accepted by consumers. It is not something that can be done.

In addition, a technique using a sea-island type composite fiber composed of two kinds of components having different average refractive indexes as an opaque fiber itself has been disclosed (Japanese Patent Publication No. 46-3814). Although this does not show the disadvantage of the method by the post-processing,
It is difficult to say that it is an economical method, because specific restrictions are applied to the components used, it is difficult to suppress the influence of the light reflected from the fiber surface, and a complicated manufacturing device is required.

In addition to this, JP-A-55-158331 proposes a core-sheath type composite fiber in which a large amount of titanium oxide is contained in the core. However, this fiber itself is not opaque as a woven or knitted fabric because it cannot cover the interstices of its structure when it is made into a woven or knitted fabric even though it is opaque.

(Problems to be Solved by the Invention) In view of such circumstances, the present inventors have dispersed the above-mentioned inorganic fine powder such as titanium dioxide in a resin binder so as not to impair the original feeling and characteristics of the fiber and the surface of the fabric. Whatever the conventional post-processing method, such as those that have been subjected to coating processing, or those that have resin coatings with different refractive indexes formed on the fiber surface, and those that have minute irregularities formed on the fiber surface,
As a result of earnest research to arrive at the present invention, synthetic fiber filament fabrics having permanent opacity comparable to natural fiber fabrics are obtained in an industrially advantageous manner by repeatedly designing the raw fibers and devising the weaving processing stage. It was done.

(Means for Solving Problems) The present invention provides a multifilament containing flat filaments having a flatness of 1.4 or more and a fineness of 0.05 to 5 denier in a fineness ratio of at least 30% at least 50% of warp and / or weft.
In the cross section of the woven fabric, the flat filaments arranged at an angle of less than 45 ° between the long axis of the cross section of the flat filament and the woven surface occupy at least 50% of the entire flat filament, and a basis weight of 300 g / m ² or less, A woven fabric having a thickness of 0.65 mm or less and having a light transmission index satisfying the following formula and having excellent opacity D × T ≦ 6 (where D: unit weight (g / m ² ), T: light transmission index), The method of the present invention has a flatness of 1.4 or more,
When processing a woven fabric using multifilaments containing at least 30% of flat filaments having a fineness of 0.05 to 5 denier in a fineness ratio of at least 50% of the warp and / or the weft, a plurality of times in the warp and / or the weft direction of the woven fabric is used. After applying tension / relaxation, the woven fabric is pressed in the vertical direction using a calender roller, and at least 50% of the flat filaments are
In the woven fabric cross section, the angle between the long axis of the flat filament and the woven fabric surface is arranged to be less than 45 °, and the fabric weight is 300 g / m ² or less, the thickness is 0.65 mm or less, and the light transmission index satisfying the above formula is provided. It is characterized by

 The present invention and the method of the present invention will be described in detail below.

First, the flat filament will be described. The fiber flatness generally refers to the ratio (L / l) of the major axis length L and the minor axis length 1 in the cross section of the fiber. What is judged to be flat at first glance as shown in FIG. 1 (a) may be expressed by the numerical values of L and l shown in the figure. However, if the ribbon is curved, or if it is a multi-sided shape with roughly four sides or a polygonal shape with four sides or less, the maximum length at the time of projection is L and the minimum length is as shown in FIG. 1 (b). Define the length as l. The flatness of the flat filament used in the present invention needs to be 1.4 or more in the above definition. This is to increase the reflection of light on the flat surface, and if the light reflection is large, the light entering the cloth is naturally suppressed, and further, the light is naturally attenuated while repeating the mutual reflection between the fibers in the cloth, and goes out of the cloth. It is possible to reduce the amount of leaked light to the extent that it does not interfere. Flatness 1.
When it is less than 4, the flatness is about the triangular cross-section yarn obtained by ordinary spinning, or the round cross-section yarn deformed by high temperature false twist, and only the opacity of the fabric according to the conventional technique can be obtained. is necessary. To further enhance the effect, the oblateness is preferably 1.6 or more, and it is more desirable that the fiber cross section has at least one linear smooth side, preferably two sides. However, even if the side is not smooth and the unevenness is increased by false twist, the purpose can be achieved if the oblateness is sufficiently large.

Further, the flat yarn may be hollow, and rather hollow is more effective for preventing glare on the surface.

Furthermore, in order to increase the coverage by crimping and improve the feel,
It is effective to apply false twisting treatment. The false twisting method is roughly classified into a spindle false twisting method and a friction false twisting method. For the purpose of the present invention, a belt type or a disk type friction false twisting method is suitable. This is because the cross-sectional deformation applied to the false-twisted yarn by mechanical and thermal forces during false-twisting is smaller in the friction false-twisting method, and it is easier to maintain the shape designed and spun in such a shape for the purpose of the present invention. Is.

The fineness of the flat yarn is in the range of 0.05 to 5 denier, 0.2
~ 2 denier is preferred. Flat filaments having a denier of 1 denier or less are difficult to obtain by ordinary melt-spinning, but by complex spinning with a combination of polyester and a poorly compatible polymer such as polyamide, After the yarn having such a cross-sectional shape is formed, it is opened by mechanical stimulation, physical heat shrinkage, chemically applying a swelling agent to one component, and the like, and a flat yarn having a fineness of 1 denier or less can be obtained. But,
Flat yarns less than 0.05 denier are too small,
It is not preferable because it may deteriorate the wrinkle resistance of the fabric.
On the other hand, if it exceeds 5 denier, the texture becomes coarse and hard, which is not preferable. It is more preferably in the range of 0.2 to 2 denier in consideration of the spinnability, the ease of handling of the yarn, the feel of the fabric and the like.

In the present invention, when weaving, the flat filaments may be used in the most suitable form in consideration of the texture, the finishing agent and the like. For example, when the fabric structure has a single structure such as plain weave and twill weave, if only the filament is used for the warp and weft,
Although the effect can be very good, the purpose can be achieved by using a mixed yarn by mixing and twisting with the ordinary yarn, or by weaving with the ordinary yarn. Further, in the case of a multiple weave such as a double weave, it is not necessary to use only the filament, and it is possible to obtain a sufficient effect only by using the filament for the front and back constituent yarns. Similarly, it is also effective to interwoven with the normal yarn in the front or back structure, and it is also possible to mix and twist with the normal yarn in advance. However, in the present invention,
At the time of weaving, the flat filaments should have a fineness ratio of at least
Multifilaments containing 30% must be used for at least 50% of the warp and / or weft. This is because the concealing effect is produced by uniformly arranging the flat surfaces on the surface of the woven fabric. When the mixing ratio of the flat filaments in the multifilament is less than 30% in the fineness ratio, the concealing effect of the multifilament itself is lowered, and even when the flat filaments are contained in the multifilament in a fineness ratio of 30% or more, the multifilament 50% of warp and / or weft
If used below, the opacity effect as a fabric is reduced. In general, warp yarns have a higher driving density than weft yarns and contribute to opacity, and warp yarns are more likely to have stable dimensions, and the form such as crimp in fabric is stable. It is effective to use multifilaments containing the flat filaments in the warp due to their ease.

In the present invention, the polymer forming the flat filament may be any fiber-forming synthetic linear polymer, but is preferably polyester and / or polyamide, and a multifilament including the flat filament is also preferable. It is preferably polyester and / or polyamide. Examples of the polyester as used herein include polyethylene terephthalate, polyethylene isophthalate, copolymerized polyethylene terephthalate, polybutylene terephthalate, and the like. Examples of polyamides include aliphatic polyamides such as nylon 6, nylon 66, nylon 610, and polyxylylene. Aromatic polyamides such as adipamide and polyhexamethylene phthalamide can be mentioned.
Further, various additives, especially matting agents, pigments, dyes, lubricants, crystal nucleating agents, are added to the fiber-forming synthetic linear polymer used.
It may contain inorganic or organic powder such as a catalyst.

The opaque woven fabric obtained by the present invention has a basis weight of 400 g / m ²
Hereinafter, the thickness is 0.8 mm or less. If the fabric weight exceeds 400 g / m ² , the clothes become too heavy and wearability is impaired. Thickness
If it exceeds 0.8 mm, it becomes a thick woven fabric, which impairs activity when worn, which is not preferable. The opacity of the woven fabric obtained by the present invention is higher than that of the conventional synthetic filament woven fabric by the unit weight of 30%.
It is particularly remarkable when the thickness is 0 g / m ² or less and the thickness is 0.65 mm or less.

The opaque woven fabric of the present invention is such that, in the cross section of the woven fabric, the flat filaments arranged at an angle of less than 45 ° between the long axis of the flat filament and the surface of the woven fabric occupy at least 50% of the entire flat filament. You have to be fake. If it is less than 50%, the opacity effect of the fabric is reduced.

As a method of making such a specific arrangement, after applying tension / relaxation to the fabric in the warp and / or weft directions a plurality of times, pressing / relaxing is performed a plurality of times in the thickness direction of the fabric. Spiral brakes, camfots, sanforises, etc. are effective for applying tension / relaxation in the warp and / or weft direction of the fabric, and a Simily calendar, for pressing in the thickness direction,
Cold calendars are effective.

In the processing, it is acceptable to use an antistatic finish, a water-repellent finish and an oil-repellent finish. There is no problem in coating resin liquids such as urethane and acrylic. A urethane or fluorine resin film may be laminated.

The woven fabric thus obtained is measured for light transmission index by the following method.

Generally, the Pineo's formula is useful for the optical density of light transmitted through a dyed fabric. Function F related to spectral reflectance R
(R) is known as a function relating to the ratio K / S of the absorption coefficient K and the scattering coefficient S, and is represented by the following equation.

The K / S of the sample cloth can be obtained from the conversion table by measuring the R% of the dyed cloth with a self-recording spectrophotometer equipped with an R cam.

For the opacity (hiding power) of the sample, determine the R% of the sample cloth at a wavelength of 600 nm, obtain the K / S value, and use the following formula to calculate Δ (K / S)
And is expressed as a light transmission index T.

T = Δ (K / S) = (K / S) _B − (K / S) _W where (K / S) _B , (K / S) _W is the black and white mounts on the back of the sample, respectively. The K / S at a wavelength of 600 nm on the surface of the cloth when applied. Therefore, the smaller the T value, the higher the opacity.

Generally, the light transmission of a fabric decreases with the increase of the basis weight.
The light transmission index by the above measurement method is T, and the basis weight is D (g / g
m ² ), the relationship of T × D> 8 is obtained for the conventional filament woven fabric for general clothing, whereas in the case of the woven fabric according to the present invention, the range of opacity is T × D ≦
It is necessary to have a relationship of 6. In order to make it within such a specific range, depending on the target fabric weight, the weaving density during weaving, the presence or absence of twist, the presence or absence of sizing, the width during processing, the conditions such as pressing, and false twisting conditions, etc. It needs to be selected appropriately. When opacity is particularly required, the range is T × D ≦ 5, and in the most severe case, T × D ≦ 4.

(Effects of the Invention) The woven fabric according to the present invention has extremely good opacity, and is almost the same as before washing even after 30 times of washing. It is also easy to wear. The woven fabric of the present invention is particularly suitable for women's clothing such as thin blouses, dresses, skirts and slacks.

Example 1 Various 150d polyethylene terephthalate (hereinafter abbreviated as polyester) semi-dal filaments (containing 0.5% by weight of titanium dioxide) having a cross section as shown in FIG. A 2/2 twill weave was obtained by plying 150d / 32f of regular polyester bright filaments with a circular cross section and 150T / M in the S direction and using it for warp and weft. The obtained woven fabric was dyed with a white fluorescent dye (Hostalix JP, Hoechst Co., Ltd.) at owf 0.5%, 130 ° C. for 60 minutes,
It was treated with a conventional antistatic finish. Next, after applying tension / relaxation in the warp and weft directions like loosening the fabric with a spiral brake, pass through a Simile calendar three times, and then
Dry heat set at 170 ° C. Table 1 shows the physical properties of the obtained woven fabrics. Further, the cross section of the woven fabric was observed with an electron microscope, the angle of the flat yarn with respect to the woven fabric surface was observed, and the proportion of the flat yarn which was less than 45 ° was calculated.

It has been found that a flatness of 1.4 or more, preferably 1.6 or more is required. Further, if the fineness is not less than 5d, the softness is lost because the pressure is applied in the thickness direction.

Example 2 As shown in FIG. 2 (b), a laminated composite yarn of polyester semi-dal (containing 0.5% by weight of titanium dioxide) and 6 nylon fulldal (containing 2% by weight of titanium dioxide) having a cross section was prepared. Within the base, 1/1 with polyester and 6 nylon
It was obtained by repeating the division with a static mixer in the mouthpiece after bonding to the dorso-ventral structure at a volume ratio of. At this time, the number of splitting stages was changed by changing the number of static mixers in the spinneret to make four types of composite yarn, but all were unified to 150d / 32f. The obtained composite yarn is false twisted at a temperature of 195
Spindle false twist was performed in the S direction at a temperature of 2400 T / M at ℃. A plain woven fabric was obtained by using a regular polyester semi-dal filament 150d / 48f false twisted yarn under the same conditions as a warp and the false twisted composite yarn as a weft. This woven fabric was treated in the same manner as in Example 1. The results are shown in Table 2.

Example 3 Polyester semi-dal filaments 30d / 12f, 50d / 24f, 75d / 36f having an oblateness of 2.0 as shown in FIG. 1 (a) were each subjected to a disk type false twisting machine at a temperature of 215 ° C. and a twist number of 800 + 275,000 /.
The S false twist was performed with the number of twists satisfying the formula of (fineness +60). This false twisted yarn and regular polyester filament false twisted yarn 75
Combined with d / 36f, 50d / 24f, 80d / 12f, the fineness is 100 to 105d. These yarns were used as warp yarns, and at the same time, false twisted yarns of regular polyester filament 100d / 24f were alternately used as warp yarns to change the use ratio. A regular woven filament of 100d / 24f was woven into the weft to make a plain weave. The obtained woven fabric was treated in the same manner as in Example 1. The results are shown in Table 3.

Opacity is good when the mixing ratio of the flat yarns in the compound filament is 30% or more and the usage ratio in the warp yarns is 50% or more.

Example 4 A polyester type semi-filament 150d / 32f having an oblateness of 2.0 as shown in FIG. 1 (b) was heated with a disk type false twisting machine.
S false twist was carried out at 215 ° C and the number of twists of 2100 T / M. The obtained false-twisted flat yarn is twisted in the S direction at 150 T / M and used as warp and weft.
Got 2 twills. This woven fabric was dyed with a white fluorescent dye (Hostalix JP, Hoechst Co., Ltd.) at owf1%, 130 ° C. for 60 minutes.
The fabric was then tensioned / relaxed with a spiral brake and then passed through a Similly calender. At this time, we made four kinds of fabrics with different numbers of passes through the Similly calendar,
It was set at 180 ℃ dry heat. Table 4 shows the results.

The proportion of flat yarns whose angle between the long axis of the flat yarns and the surface of the fabric is less than 45 ° must be 50% or more.

[Brief description of drawings]

FIGS. 1 (a) and 1 (b) illustrate how to measure the major axis L and the minor axis l used in the formula of the oblateness of a flat filament in the present invention. 2 (a) and 2 (b) are cross-sectional morphologies of fibrillated composite filaments for use in the present invention for producing flat yarns of 1d or less, and FIG. 3 is the yarn of FIG. 2 (b). 2 is a photograph of an ultrafine flat yarn after fibrillation.

 ─────────────────────────────────────────────────── ─── Continuation of front page (56) Reference JP-A-56-68163 (JP, A) JP-A-56-49077 (JP, A) JP-A-59-116467 (JP, A) JP-A-55- 30460 (JP, A) JP 56-148940 (JP, A) JP 56-148942 (JP, A)

Claims (1)

(57) [Claims] 1. A multifilament containing at least 30% by flatness filament having a flatness of 1.4 or more and a fineness of 0.05 to 5 denier in a fineness ratio of at least 50 in a warp and / or a weft.
When processing the woven fabric used in%, after subjecting the woven fabric to tension and relaxation in the warp and / or weft directions multiple times, press the woven fabric up and down with a calendar roller to obtain at least 50 flat filaments. In the cross section of the woven fabric, the angle between the long axis of the flat filaments and the woven fabric surface is arranged to be less than 45 °, and the light transmission index that is less than 300 g / m ² and has a thickness of 0.65 mm or less and that satisfies the following formula: A method for producing a woven fabric having excellent opacity, which is characterized by being provided. D × T ≦ 6 (however, D: basis weight (g / m ² ), T: light transmission index)