JPH11124773A - Production of fiber construction having improved optical interference function - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a fiber construction capable of providing an interference color with deeper color as a fiber aggregate without possibility of uneven attachment of a low refractive index polymer effective for reduction of surface reflected light. SOLUTION: A solution of a polymer having a refractive index lower than that of a polymer having the highest refractive index in the polymers constituting optical interference fibers is attached to a fiber construction including the optical interference fibers obtained by alternatively laminating at least two kinds of the polymers having different refractive indexes arranged along the major axis directions of flat cross sections, and having flat surfaces and the flat cross sections with >=4 flatness ratio, to provide a polymer coating membrane of the polymer solution at least on the surfaces of the optical interference fiber in the method for producing a fiber construction having an improved optical interference function.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fiber structure having an improved optical interference function, and more particularly, to a fiber structure having an improved optical interference function of emitting light by reflecting, interfering or diffracting or scattering light. It relates to a fiber structure.

[0002]

2. Description of the Related Art In recent years, due to the demand for high-quality texture of fabrics, sensible fibers such as bulges have been developed by combining a simple round cross-section yarn with a modified cross-section and further combining two or more fibers, and have flourished as a new synthetic fiber. . Recently, fibers having higher sensitivity and function have been demanded. One of them is deep color and gloss. However, if you try to satisfy the deep color and gloss at the same time, you can get the deep color effect,
The color becomes dull and loses vividness. On the other hand, when trying to obtain luster, it becomes dull (Adahikari), and there has not been a technology to achieve both. The reason is that in the prior art, color is developed by dyes and pigments,
That is, since the color is developed by absorbing light, the more the deep color effect is obtained, the more the reflected light decreases, and the gloss disappears.

On the other hand, when overlooking the natural world, for example, a beetle or a morpho butterfly satisfies both deep color and luster at the same time, and exhibits a color completely different from dyes and pigments. This coloring mechanism is based on light reflection and interference. And
Various approaches have been devised for synthetic fibers utilizing this mechanism. For example, JP-A-7-34320, JP-A-7-34324, and JP-A-7-34324
Japanese Patent No. 331532 discloses a flat light coherent monofilament having a multilayer thin film structure in which polymers having different refractive indexes (here, optical refractive indexes) are alternately laminated and having an aspect ratio of 3.5 or less.

Further, Japanese Patent Application Laid-Open No. Sho 62-170510 discloses a technique for making the interference color even darker by reducing the amount of surface reflection from the fiber surface of the fiber emitting the interference color. This technique covers a fiber having fine grooves in units of 1/10 micron to micron with a polymer film having a refractive index lower than that of the constituent material (polymer) of the fiber, as shown in FIGS. Things. Certainly,
According to this technique, the surface reflection light from the fiber is reduced, but in reality, the adhesion unevenness is unavoidable in a narrow groove of 1/10 micron to micron unit. Moreover, the narrow groove itself is
Needless to say, it is easily affected by contact wear with guides and rollers, and easily changes in shape. Therefore,
The deformation of the narrow groove and the uneven adhesion of the polymer film in the narrow groove may impair the intended interference effect itself.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a fibrous structure which can emit a darker interference color as a fiber aggregate without fear of the above-mentioned uneven adhesion of the resin film. .

[0006]

According to the present invention, at least two kinds of polymers having different refractive indexes are alternately laminated along the long axis direction of a flat cross section, and the surface is flat and the flatness is 4%. To the fiber structure containing the light interference fiber of the above flat cross section, a polymer solution having a lower refractive index than the refractive index of the polymer having the highest refractive index among the polymers constituting the light interference fiber, A method for producing a fiber structure having an improved optical interference function, comprising forming a film of a polymer in the polymer solution on at least the surface of the optical interference fiber.

FIG. 1 is a sectional view of a light interference fiber (filament) used in the present invention. FIG. 1A shows a shape in which polymers A and B having different refractive indices are alternately laminated in the major axis direction of the flat cross section, and FIG. 1B shows a shape of the hollow flat cross section. FIG. 1- (c) shows a shape in which a reinforcing portion (film) of the above-mentioned A, B, or another polymer is interposed in the intermediate portion of the alternate lamination, and FIG. 1- (d) shows a reinforcing portion (film) in the outer peripheral portion.
The shape provided with is shown.

In the present invention, a filament (monofilament) having a flat surface, which is resistant to abrasion, as described above.
Applying a solution containing a low-refractive index polymer to an aggregate having constituent units, for example, a woven fabric containing a multifilament yarn,
A coating of the polymer is formed on the filament surface.
In this case, it is most important to maximize the optical interference effect of the multifilament yarn as a whole, while reducing the surface reflected light due to the formation of the low refractive index polymer film. For this reason, filaments having an aspect ratio of 4 to 15 are used.

Here, the oblateness is the length W of the long axis of the oblate cross section.
And the ratio W / T of the length of the short axis to the length T of the minor axis. Regarding this flatness, as has been conventionally proposed, 3.5 is sufficient to obtain the light coherence as a filament. However, when a plurality of such filaments are collected and used as a multifilament, the flat long axis surfaces of the filaments are randomly arranged and bundled, so that the light interference function cannot be effectively exerted as a whole multifilament yarn. .

However, when the flatness is 4, preferably 4.5 or more, a self-orientation control function is added to each filament constituting the multifilament yarn, and the flat long axis of each constituent filament is controlled. The multifilament yarns are assembled by assembling such that the surfaces are parallel to each other. That is, such a multifilament is used when a filament is pressed against a take-up roller or a drawing roller in the process of forming the filament, or when wound on a bobbin in a cheese form, or in a process such as knitting or weaving a fabric. Each time, for example, when receiving a superior pressure contact, the flat long axis surfaces of the filaments are gathered so as to be parallel to the pressure contact surface, so the parallelism of the flat long axis surfaces of the constituent filaments in the multifilament is reduced. High, and excellent light interference as a fabric can be obtained.

On the other hand, if the oblateness exceeds 15, the shape becomes excessively thin, so that it is difficult to maintain the cross-sectional shape, and there is a concern that a part of the cross-section may be bent. From this point, the easy-to-handle flatness is 15 or less, particularly 10 or less.

As described above, the flatness of the filament is 4 to
15 and larger than the conventional optical interference monofilament, so that the number of alternately laminated layers is at least 5
The number of layers is preferably larger than the conventional number of layers, preferably 15 or more, more preferably 20 or more, and most preferably 25 or more.

According to the theory of optical interference, according to the theory of optical interference, when the thickness of each layer is equal to the set value, if there are at least 5 layers and at most 10 layers, the obtained interference light quantity reaches a saturation state. However, in practice, unevenness in thickness occurs inevitably in the spinning process. Therefore, when the number of laminations is about 10, the light interference effect becomes insufficient. In this sense, if the number of layers is preferably 15 or more, more preferably 20 or more,
The aforementioned disadvantages are compensated. On the other hand, the upper limit is 120 layers,
In particular, considering the complexity of the spinneret and the control of the molten polymer flow, the number of layers is 70.

The optical coherent multifilament of the present invention has an elongation in the range of 10 to 60%, preferably 2 to 60%.
It is preferably in the range of 0 to 40%. This is because the bifilament index (Δn) is further increased by stretching the multifilament spun and cooled and solidified once, and the difference in the refractive index between the polymers is defined as the difference of “the refractive index of the polymer plus the birefringence of the fiber”. As a result, the difference in the refractive index as a whole is enlarged, and thereby the optical coherence is enhanced.

The fiber structure in the present invention means a tow, a multifilament yarn, a woven or knitted fabric, a nonwoven fabric, a paper-like material, etc., composed of a light interference filament. A low refractive index polymer is applied to these structures in the form of an organic solvent or an aqueous emulsion. As an application means, that is, a coating method, any method such as a padding method, a spray method, a kiss roll method, a knife coating method, and a bath adsorption method can be used.

By the way, of the two-component polymers constituting the light interference filament, the polymer having the higher refractive index generally has a refractive index of 1.49 to 1.88.
Therefore, as a low refractive index polymer for forming a film,
It is preferable to appropriately select one having a refractive index in the range of 1.35 to 1.55.

Examples of the polymer having a small refractive index in the present invention include, for example, polytetrafluoroethylene, tetrafluoroethylene-propylene copolymer, tetrafluoroethylene-hexafluoropropylene copolymer,
Tetrafluoroethylene-ethylene copolymer, tetrafluoroethylene-tetrafluoropropylene copolymer, polyfluorovinylidene, polypentadecafluorooctyl acrylate, polyfluoroethyl acrylate, polytrifluoroisopropyl methacrylate, polytrifluoroisopropyl methacrylate, polytrifluoroethyl methacrylate, etc. A fluorine-containing polymer,
Examples include silicon-containing compounds such as polydimethylsilane, polymethylhydrodiethylenesiloxane, and polydimethylsiloxane; ethylene-vinyl acetate copolymer; acrylic esters such as polyethyl acrylate and polyethyl methacrylate; and polyurethane polymers.

In another embodiment of the present invention, when another type of fiber is used in combination with the fibrous structure, it is preferable to use a dark-colored fiber as the other type of fiber. . Thereby, the coloring effect by using a monofilament having an oblateness of 4 or more as a constituent unit of the multifilament yarn is sufficiently emphasized.

In this regard, the light coherent filament develops color due to interference between incident light and reflected light. By the way, the human eye recognizes the color intensity based on the difference between the interference light reflected from other parts and the stray light entering the eye. Therefore, when stray light from the surroundings is strong, even if there is sufficient interference light, it cannot be recognized as a color. As a method for preventing stray light, it is preferable to use a fiber having a function of absorbing stray light as another kind of fiber which is located at a position closest to the light interference filament, which reflects light from around. In order to absorb stray light, it is preferable to use dark-colored fibers and / or original fibers having an L value of 40 or less. In particular, black is preferable because it absorbs all light and has a large effect of removing stray light. Further, it is more preferable to use a dark-colored fiber having a hue complementary to the color of the light interference filament. Fibers colored with a hue that is complementary to the interference light absorb light of the complementary color and reflect light of a wavelength near the light interference light. That is,
In such a tissue, since the interference light and the light having the same wavelength as the interference light in the stray light portion can be used as the reflected light, the intensity of the reflected light is further increased, and the difference between the stray light from the other portions is different. There is an advantage that it can be taken out as a large one.

Although the L value can be read directly by a color difference meter, in the present invention, a type ND-101DC manufactured by Nippon Denshoku Industries Co., Ltd. is used.
The L value is measured using a colorimeter.

A method for producing the light interference multifilament yarn used in the present invention will be described. First, as a combination of polymers, an aromatic polyester such as polyethylene terephthalate, polybutylene terephthalate, or polyethylene naphthalate, or a polycarbonate is preferable as a polymer having a fiber forming property with a high refractive index.
The refractive index of these polymers is, for example, 1.58 for polyethylene terephthalate, 1.63 for polyethylene naphthalate, and 1.5 for polybutylene terephthalate.
It has a high value of 5. Further, polycarbonate has a high value of 1.59. Further, when a fiber is formed using these polymers, a high orientation occurs in the fiber axis direction, and the fiber has a large birefringence. The birefringence has high values such as 0.22 for polyethylene terephthalate, 0.487 for polyethylene naphthalate, 0.153 for polybutylene terephthalate, and 0.20 for polycarbonate. As the refractive index as a fiber, a refractive index in consideration of a birefringence in addition to a refractive index specific to a polymer can be used.

On the other hand, examples of the polymer having a low refractive index include methacrylates such as polymethyl methacrylate, polyvinyl ethers, polyolefins such as polyethylene and polypropylene, polystyrenes, and aliphatic polyamides such as nylon 6. On the other hand, these birefringences are almost 0 for polymethyl methacrylate, 0.19 for polystyrene and 0.09 for nylon 6.
8 or the like, which is lower than that of the high refractive index polymer.

Among the above, the following combinations are particularly preferable from the viewpoint of ensuring compatibility (adhesion) between the respective layers.

(A) Polyester containing polyethylene naphthalate as a main component, in which a dibasic acid component having a sulfonic acid metal base is copolymerized in an amount of 0.3 to 5 mol% based on all dibasic acid components forming the polyester (High refractive index polymer) and aliphatic polyamide (low refractive index polymer). (B) the dibasic acid component having a sulfonic acid metal base is 0.3 to 0.3 to the total dibasic acid components forming the polyester;
Polyester mainly composed of polyethylene terephthalate copolymerized at 10 mol% (high refractive index polymer)
And polymethyl methacrylate having an acid value of 3 or more. (C) a dibasic acid component and / or a glycol component having at least one alkyl group (for example, a methyl group) in a side chain as a copolymer component (for example, neopentylene glycol, bisphenol A or an alkylene oxide adduct thereof), 5 to 3 copolymer components per total repeating unit
A combination of a copolymerized aromatic polyester (high refractive index polymer) copolymerized with 0 mol% and polymethyl methacrylate (low refractive index component).

The above-mentioned two types of polymers are spun from a die as shown in FIG. Here, FIG. 2- (a) is a partially cut perspective view showing an example of the base used in the present invention. In the figure, 1 is a distribution plate, 2 is an upper die, 3 is a middle die, 4 is a lower die, and these four disk-shaped components are laminated. Flow paths 5 and 6 are provided for supplying the polymers A and B by separate paths.
The upper base 2 is provided with a flow path for guiding the polymer A to the row of openings 7, and a flow path 6 ′ for guiding the polymer B to the center of the base. The polymer B guided to the center of the middle base 3 passes through a flow path 8 provided radially on the upper surface of the middle base 3 and further to a funnel-shaped part 9 provided parallel to the flow path 8. 10 passes through the upper surface as a band-like flow. As described above, the polymer A flowing out of the row-shaped openings 7 enters the polymer B passing through the upper surface of the weir-like portion 10 in a strip shape, and the polymer A and the polymer B
Flows into the funnel-shaped part 9 in a form of being alternately laminated in layers (see the arrow in FIG. 2). Is enlarged, and the polymer in which a large number of polymers are stacked gradually becomes shorter. Further, the polymer laminar flow emerging from the discharge port 11 is spun through a final spinning port 12 opened in the lower die 4.

FIG. 2B is a cross-sectional view showing a modification of the base when the reinforcing layer (protective layer) shown in FIG. 1 is formed. Here, a reinforcing layer is formed in the vicinity of the funnel-shaped portion 9 of the middle die 3 of the die shown in FIG.
To form a structure in which the polymer is merged with the main polymer stream through an annular polymer reservoir 15 and an annular flow path 16 surrounding the upper part of the spinneret 12 via a gap 14 between the middle die 3 and the lower die 4. Has become.

[0027] The spun alternately laminated product is wound up and then hot-drawn (separate drawing method), stretched and then drawn up and wound up, or drawn yarn using high-speed spinning. What is necessary is just to wind up as a multifilament yarn corresponding to. Among these, the separate method is the most effective method for increasing the birefringence between the laminated polymers described above.

In the finally obtained monofilament having an alternately laminated structure, the thickness of each polymer layer is preferably 0.01 μm or more and 0.4 μm or less.
On the other hand, the thickness of the reinforcing portion is preferably 2 microns or more. When the thickness is less than 2 microns, the reinforcing layer and the multilayer molded layer are peeled off due to friction occurring in practical use. On the other hand, if it exceeds 10 microns, light absorption and diffuse reflection at the reinforcing portion cannot be ignored, which is not preferable.

The thickness (denier) of the monofilament and the thickness (denier) of the multifilament yarn may be appropriately set in consideration of the texture and performance of the intended woven fabric. Generally, the former is selected from the range of 2 to 30 denier, and the latter is selected from the range of 50 to 300 denier.

[0030]

According to the present invention, the reduction of the reflected light from the surface by the coating of the low refractive index polymer is only an auxiliary as far as the light interference is concerned. It is based on the idea of improving. In other words, filaments that have excellent light coherence in themselves, and why the light interference effect is hindered in an aggregated state like a multifilament, as a result of pursuing the cause, as a result, It has been found that the multifilament has a filament aggregate structure. That is, the light interference filament has a flat cross-sectional shape, and has a structure in which polymers are alternately laminated in parallel with its long axis direction, so that the light interference filament is formed by the long axis side and the filament length direction side. When viewed from a direction perpendicular to the filament surface, the color development due to light coherence can be visually recognized most strongly, and when viewed obliquely at an angle higher than that, the visual effect rapidly decreases. On the other hand, when the side in the short axis direction of the flat cross section is viewed from the filament surface formed by the side in the filament length direction,
It has an optical interference characteristic that optical interference cannot be visually recognized at all.

On the other hand, when forming a fabric as a multifilament by collecting light interference filaments having a flat cross-sectional shape, they are gathered in a direction in which the filaments are most closely packed in the cross section of the multifilament due to tension, frictional force, etc. acting on the filament. . For this reason, paying attention to the filament surface formed by the long axis direction side and the filament length direction side of the flat cross section, and examining the parallelism of the surface between the constituent filaments, the uniformity is poor and various Was facing a different direction.

From the recognition of the problems described above and the analysis of the causes, when the tension or frictional force in the process is applied to the filaments constituting the multifilament, the filaments gather on their flat surfaces in parallel to each other. It is a requirement of an aspect ratio of 4 or more to provide a self-orientation control function that can constitute a multifilament yarn. At the same time, according to the present invention, since such a flat yarn has a flat surface, not only is it excellent in abrasion resistance and shows permanent interference, but also there is no concern about uneven adhesion of the low refractive index polymer. As a result, the surface reflected light by the uniform coating of the polymer is reduced, so that a high interference color is obtained.

[0033]

【Example】

Example 1 Polyethylene naphthalate (intrinsic viscosity: 0.58; naphthalenedicarboxylic acid: 89 mol%) obtained by copolymerizing 10 mol% of terephthalic acid and 1 mol% of sodium sulfoisophthalic acid, and nylon 6 (intrinsic viscosity = 1.
3) is subjected to composite spinning under a volume ratio of 2/3 (composite ratio) using a die shown in FIGS.
An undrawn yarn having a flat section and a lamination number of 30 was wound at a winding speed (spinning speed) of 1500 m / min. 11
It was drawn 2.0 times with a roller type drawing machine consisting of a supply roller heated to 0 ° C. and a drawing roller heated to 170 ° C. to obtain a drawn yarn of 90 denier / 12 filaments. When the film thickness of the two polymer layers at the center of the flat yarn was measured, the thickness of the polyethylene naphthalate layer was 0.07.
μ and the thickness of the nylon layer were 0.08 μ, and a green interference color was observed. The flatness of the monofilament was 5.6.

The thus obtained multi-filament yarn having an optical interference effect is used for the weft, and a black denatured yarn of 75 denier / 24 filament is used as the warp to produce an 8/2 (4 shift) satin fabric. did. Next, the woven fabric was treated with polydimethylsiloxane (low refractive index agent, refractive index =
1.40), immersed in a 60% pickup with a mangle (0.5% adhered to the fiber as a polymer amount), dried, and heat set (160
C. for 1 minute). The resulting fibrous structure was a deep-colored green color with a strong luster and a texture completely different from the texture obtained by conventional dyeing.

[Examples 2 to 4 and Comparative Examples 1 and 2]
In the above, instead of polydimethylsiloxane, it was immersed in an emulsion solution of various low refractive index polymers, squeezed with a mangle, dried, and heat set (160 ° C. for 1 minute). Table 1 shows the results.

[0036]

[Table 1]

[0037]

According to the present invention, a monofilament effectively reflects light, and an alternately coherent light-interfering filament which is effective in interfering with light can exhibit the same effect in a multifilament yarn. Combined with the effect of reducing the surface reflected light by the low refractive index polymer film, a fabric that satisfies the texture and coloring is realized.

[Brief description of the drawings]

FIG. 1 is a sectional view of a unit constituting a light coherent multifilament yarn used in the present invention, that is, a monofilament.

FIG. 2 (a) is a partial cross-sectional perspective view of a die used for spinning a light coherent multifilament yarn used in the present invention. (B) is a partial sectional view showing a variation of the base of (a).

[Explanation of symbols]

 Reference Signs List A Polymer layer B Polymer having a different refractive index from polymer layer A 1 Distribution plate 2 Upper ferrule 3 Middle ferrule 4 Lower ferrule 5 Flow path 6 Flow path 7 Row of openings 8 Radial flow path 9 Toroidal section 10 weir 13 reinforced polymer flow path 14 reinforced polymer flow path 15 reinforced polymer flow path 16 reinforced polymer flow path

────────────────────────────────────────────────── ─── Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI G02B 1/04 G02B 1/04 // D02G 1/18 D02G 1/18 (72) Inventor Toshimasa Kuroda 3-chome, Ohara, Ibaraki-shi, Osaka 4-1 Teijin Limited Osaka Research Center (72) Inventor Kinya Kumazawa 2 Takara-cho, Kanagawa-ku, Yokohama, Kanagawa Prefecture Nissan Motor Co., Ltd. (72) Hiroshi Tabata 2 Takara-cho, Kanagawa-ku, Yokohama, Kanagawa Inside Nissan Motor Co., Ltd. (72) Inventor Susumu Shimizu 2-73, Shinmachi, Hiratsuka-shi, Kanagawa Prefecture Inside the Technology Development Center, Tanaka Kikinzoku Kogyo Co., Ltd. Isehara factory

Claims (8)

[Claims] 1. A method in which at least two kinds of polymers having different refractive indexes are alternately laminated along a long axis direction of a flat cross section.
In a fibrous structure including a light coherent fiber having a flat surface and a flat cross section having a flattening ratio of 4 or more, a refractive index lower than the refractive index of the polymer having the highest refractive index among the polymers constituting the light coherent fiber. A method for producing a fiber structure having an improved optical interference function, comprising depositing a polymer solution having a high refractive index and forming a film of the polymer in the polymer solution on at least the surface of the optical interference fiber. 2. The optical interference fiber comprises the following (a) to (c):
The fiber structure having an improved optical interference function according to claim 1, which satisfies the following condition. (A) Flatness: 4 to 15 (b) Number of layers: 5 to 120 (c) Elongation (%): 10 to 60 3. A combination of two kinds of polymers having different refractive indices is:
2. The improvement according to claim 1, wherein the combination is a combination of a polyethylene naphthalate-based polyester (high refractive index polymer) copolymerized with 5 mol% and (b) an aliphatic polyamide (low refractive index polymer). 3. Fiber structure having an optical interference function. 4. A combination of two kinds of polymers having different refractive indices, wherein (a) a dibasic acid component having a metal salt of sulfonic acid is in a range of 0.3 to 0.3 per total dibasic acid component forming a polyester.
Polyester mainly composed of polyethylene terephthalate copolymerized at 10 mol% (high refractive index polymer)
The fiber structure having an improved optical interference function according to claim 1, which is a combination of (b) a polymethyl methacrylate having an acid value of 3 or more. 5. A combination of two polymers having different refractive indices: (a) a dibasic acid component having at least one alkyl group in a side chain and / or a glycol component as a copolymerization component, wherein the copolymerization component is The combination according to claim 1, which is a combination of a copolymerized aromatic polyester (high refractive index polymer) copolymerized in an amount of 5 to 30 mol% per all repeating units, and (b) polymethyl methacrylate (low refractive index component). A fibrous structure having an improved optical interference function. 6. The fiber structure having an improved optical interference function according to claim 5, wherein the alkyl group is a methyl group. 7. The fiber structure having an improved optical interference function according to claim 5, wherein the copolymer component is neopentylene glycol. 8. The copolymer component is bisphenol A or an ethylene oxide adduct of bisphenol A,
A fibrous structure having improved optical interference features according to claim 5.