JP3486081B2 - Polyester composite fiber - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite fiber suitable for producing a high-quality clothing material.

[0002]

2. Description of the Related Art Natural fibers such as wool, silk and cotton have variations in fiber length, fineness, shape, crimp and other structural or physical properties of individual monofilaments as compared with synthetic fibers. Fluffy and glossy feeling when the fabric becomes
Alternatively, the difference in surface touch results in the appearance of the characteristics peculiar to natural fibers. Such variations in structure and physical properties are a major difference from the synthetic fiber product, and have a presence.

With respect to synthetic fibers, various proposals have been made in order to improve the unique touch and appearance of synthetic fibers and develop the characteristics of natural fibers. For example, various techniques have been tried, such as a different shrinkage mixed yarn technology for mixing two or more yarns having different shrinkage ratios or a false twist textured yarn. Recently, a composite processed yarn made by false twisting a mixed yarn of multiple fibers with a higher degree of compositeness and different fiber (elongation), and a different shrinkage mixed fiber that uses a highly shrinkable fiber modified by a copolymer Efforts are being made to bring the sensitivities of the fabrics obtained by compounding with other technologies such as yarns and self-expanding yarns that form large loops closer to those of natural fibers, while fabrics aimed at new sensitivities not found in natural fibers. Is being developed. However, in the case of such a processing method, the improvement of the cloth is mainly made by giving the obtained woven or knitted fabric a fluffy texture, and as in the present invention, it is excellent in a tight fluffy sensation and a soft surface touch, and has a delicate surface. A material having a luster and an extremely high-quality silk filament woven fabric has not been obtained.

The excellent texture of silk filament fabric,
In particular, the "tightened feeling of fluffiness" that gives an appropriate amount of fluffiness without excessive fluffiness is manifested by a processing method that makes the most of the unique structure and characteristics of silk. That is, silk has a composite fiber structure in which two fibroin fibers each having a triangular shape are wrapped in a matrix of sericin in one thread, and after being made into a cloth, sericin should be dissolved and removed with an alkali. Produces two fibroin fibers. At that time, the two fibroin fibers that were expressed as voids with only sericin removed were subjected to a subtle twist when produced from the silkworm.Since the twist is expressed, each part has a subtle twist. Generates crimp or wave.

Thus, the silk fabric is light and has a delicate crimp of each fiber due to the voids, or has an excellent fluffiness due to the wave. Also, the fiber surface has a different luster and touch because the shape of each fiber is different.

So far, synthetic fibers, especially polyester filaments, have made considerable efforts, including heterogeneous mixed fiber technology, and have come very close to silk materials. However, there are still apparent differences in the physical properties of silk described above. The first reason is that the structure cannot be realized. As recent proposals, for example, JP-A-3-220331 and JP-A-2-22.
Different crimped composite fibers have been proposed in Japanese Patent No. 1414 and Japanese Unexamined Patent Publication No. 2-221415, but the former two are intended to improve the insufficient shrinkage of the different shrinkage mixed fiber fabric. The latter is merely for the purpose of improving the crimp developability of the side-by-side type composite fiber, and the idea of obtaining a silk-like fabric highly reproducing the characteristics of silk, which is the object of the present invention, is also shown. Of course, the same thing as the present invention cannot be obtained at all.

Further, Japanese Patent Publication No. 63-30421 discloses that
When producing crimped yarn in which polyester-based filaments with different crimping ratios are mixed, side-by-side type composite fibers having different intrinsic viscosities between polymer components are formed, and the composite ratio of each is substantially different. Discloses a differently crimped mixed yarn in which filaments having the same fineness are mixed and crimped by a heating fluid pushing nozzle. However, in this method, not only the manufacturing process becomes complicated or complicated by mixing the yarns obtained separately, but also the crimp of the filament obtained by this method has a small change in waveform and a small width. In the case of a woven or knitted fabric, it is not possible to give a sufficient feeling of fluffiness, which is the target of the present invention.

[0008]

DISCLOSURE OF THE INVENTION The present invention is capable of exerting the characteristics of a true silk filament-like woven fabric, which cannot be exhibited by conventional synthetic fiber fabrics, that is, excellent fluffiness and subtleness. It is an object of the present invention to industrially inexpensively and stably supply a polyester conjugate fiber having a random latent shrinkability and a latent crimping property that exhibits a smooth surface feel and surface touch.

[0009]

Means for Solving the Problems As a result of intensive investigations by the present inventors, the present invention has been completed. First, (1) in order to develop a good crimp, a polyester having a large shrinkage (component A) and a polyester having a small shrinkage (component B) are joined in a multilayer laminate type, and the shrinkage characteristics of the components A and B The crimping performance is expressed by utilizing the difference of. Moreover, by providing an aggregate of filaments in which the composite ratio of the A component and the B component in each filament and the composite morphology in the cross section are irregularly different, the crimps are randomized to give a feeling of fluffiness and fullness that has never been seen before. I was able to.

Next, (2) the heat shrinkage characteristics of the multi-layer laminated type filament were examined to clarify the heat shrinkage characteristics for exhibiting good crimp characteristics.

Further, (3) by setting the high-shrinkage component to the same ratio as the low-shrinkage component or to a large amount, it is possible to improve the latent crimp development power, and thus to reduce the shrinkage and crimp in the processing stage of the woven or knitted fabric. The expression was increased, and as a result, it was possible to improve the expression of dullness, stretchability, fluff, and natural surface feeling of the fabric.

That is, the present invention is a multifilament having a multi-layer laminated structure consisting of two kinds of polyester components having different shrinkage rates and continuous in the fiber axis direction, and the total boiling yield of the fibers by the boiling water treatment is 20 to 40%. , Linear shrinkage is at most 2
It is 0%, and the ratio of the crimp shrinkage ratio to the total boiling yield of the fiber is 50% or more, which is a polyester composite fiber.

A second aspect of the present invention is characterized in that, in the first aspect, the high shrinkage polyester component and the low shrinkage polyester component are 1/1 to 2.5 / 1 (weight ratio). It is a polyester composite fiber.

A third aspect of the present invention is a polyester composite fiber according to the first and second aspects of the invention, wherein the rate of change in the number of crimps of the fiber after boiling water treatment is 200% or more.

A fourth aspect of the present invention is a polyester composite fiber according to any one of the first to third aspects, which has a crimp shrinkage rate of 40% or more after dry heat treatment.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION The composite latently crimped yarn as referred to in the present invention means a filament having a multi-layered laminated structure composed of a component A and a component B having different heat shrinkage behaviors in a cross section of a single filament. The bonding form of the filament having a multilayer laminated structure in any cross-section is preferably uniform and continuous along the fiber axis direction of the filament, but a part thereof may include a discontinuous structure. . A yarn having a uniformly continuous structure is preferable from the viewpoint of stabilizing spinning and drawing operability. Here, the joining form refers to a form in which the A component and the B component are attached. The multi-layer structure means a layered structure of at least two layers, preferably 2 to 10 layers, more preferably 3 to 7 layers, in which the A component and the B component are bonded. One example is shown in FIG.

The latent crimped yarn has a circular cross-sectional shape as long as it can form and maintain the joined form of the A component and the B component and can exhibit the crimping performance aimed at by the present invention. Any of a triangular cross section, a Y cross section, a U cross section, a flat cross section, and the like may be used, and can be used properly according to the application and purpose. In particular, a triangular cross section, a Y cross section, a U cross section, a flat cross section, or other irregular cross section is preferable in terms of the randomness of the crimp structure of the fiber and the texture of the cloth.

Among them, the degree of irregularity (perimeter / diameter) is preferably 3.2 or more, more preferably 3.5 to.
It is 6.0, and more preferably 3.7 to 4.5. By adopting a cross-section fiber having such a degree of irregularity, the effect of the irregular cross-section and the multilayer laminated structure act synergistically to further increase the shrinkability / crimpness randomness between the filaments, and Increases flami between fibers and reduces friction. This makes it possible to improve the softness, fluffiness, firmness, and elasticity of the fabric, and to express the fullness and soft touch of the surface, which is unique to the present invention.

Total boiling yield (SH ₁ ) and linear shrinkage (S
H ₂ ) is determined by the method described below. Further, shrinkage by crimping (hereinafter crimp shrinkage referred to as (SH ₃₎₎ represents the difference between Zen'nie yield and linear shrinkage.

The stretched fiber (multifilament) is measured for a certain length (for example, 30 cm), and a mark is made on the fiber at a certain distance (for example, 20 cm: L ₀ ). Then, be careful not to entangle the fibers with each other, and keep the temperature at 98 ° C.
It is immersed in hot water for 15 minutes for treatment. After the treatment, take out from the hot water, taking care not to stretch the fiber, drain the water on the surface of the fiber with tissue paper, leave it in the room, and air dry it sufficiently. After air-drying, a load of 0.5 mg / d was applied to the end of this fiber to hang it vertically, and the length of the mark after treatment (L
₁ ) is measured. Further, the weight is increased to 0.5 g / d, and the length (L ₂ ) is measured.

(Total boiling yield) SH ₁ = (L ₀ −L ₁ ) / L ₀ × 100 (%)

(Linear shrinkage rate) SH ₂ = (L ₀ -L ₂ ) / L ₀ × 100 (%)

(Crimp shrinkage rate) SH ₃ = SH ₁ -SH ₂ (%)

In the present invention, the total boiling yield must be 20 to 40%. If the total boiling yield is less than 20%, it is not possible to obtain a cloth having a very low surface crimping and the appearance of random crimps and tight fukami, which is the object of the present invention. On the other hand, if it exceeds 40%, there is a feeling of fuzz on the surface, but the softness is somewhat insufficient, which is not preferable.

The conventional different-shrinkage mixed yarn is used by mixing the high-shrinking fiber and the low-shrinking fiber and sufficiently shrinking the high-shrinking fiber to give the cloth a feeling of fluffiness. However, in the present invention, the linear shrinkage ratio of the fiber is at most 20%. In the conventional different-shrinkage mixed-fiber technology, it is impossible to give a sufficient feeling of fluffiness with such a shrinkage ratio, and rather, there may be defects such as the fabric becoming stiff, but the present invention is merely The linear shrinkage ratio is at most 20%, preferably 10% at the maximum, because the random shrinkage difference does not depend on the linear shrinkage, and the crimping of the fibers causes the fluffiness of the entire fabric to appear due to the fluffiness of the yarn in the transverse direction. 20%.

The crimpability of the fiber in the present invention is related to the structure of the fiber and the shrinkage ratio, but at a low shrinkage ratio, the crimp ratio is small and the crimp number tends to increase as the shrinkage ratio increases. However, when the contraction rate is 15% or more, the crimp number almost reaches saturation. Even if the shrinkage ratio is higher than that, the effect of the conventional hetero-shrinking mixed fibers is obtained, but the effect of suppressing the shrinkage ratio and providing the lateral fuzziness of the fiber due to the crimping is not so much improved.

The feature of the present invention is that, in each filament constituting the fiber, the bonding state and the bonding ratio of the two kinds of polymers are different one by one. Therefore, the fiber state and the physical properties of each filament, for example, the straight line of each filament. The shrinkage rate, the crimped state, and the crimped state (crimp, wave) of the fiber are different in the fiber axis direction even with one fiber. In other words, it is very similar to the target state after the scouring of silk.
It goes without saying that fibers and cloths having such an extremely random crimped structure and shrinkage ratio have not been obtained so far.
No suggestions have been made.

The fluctuation of the shrinkage ratio of each filament of the fiber of the present invention is determined by the joining ratio of the two kinds of polymers constituting the fiber and the spinning / drawing conditions. That is, a filament having a large low shrinkage component ratio has a low shrinkage ratio, and conversely, a filament having a large high shrinkage component ratio has a high shrinkage ratio. A filament having a high polymer constitutional ratio of either one of them has less crimps generated in the filament. Therefore, a low shrinkage filament has a low shrinkage ratio and a small number of crimps, so that when it is made into a cloth, it appears as a loop having a gentle crimp on the surface of the cloth. Further, as described above, since the ratio of the high shrinkage component is set to be large in the whole multifilament, the number of loops on the surface is relatively small and the surface touch becomes extremely soft. This loop is very useful as it is for improving the surface touch, but if the loop is cut by sanding the surface of the fabric, a more preferable soft texture can be obtained.

In order to obtain the fabric of the present invention, not only the shrinkage of the fibers in the fiber axis direction but also the lateral fluffiness of the fibers due to crimping is necessary. It is preferable that the ratio of the crimp contraction rate is at least 20%, preferably 30 to 90%, and more preferably 40 to 80%. If it is less than 20%, the fluffiness in the lateral direction of the fiber (thickness direction of the fabric) is insufficient, and the firmness, waist and fluffiness are not sufficient. The total shrinkage rate and the linear shrinkage rate here are as defined above, but the former shows the degree of shrinkage of the fiber including the shrinkage due to the crimping, and the latter shows the pure shrinkage by removing the shrinkage due to the crimping of the fiber. It shows the shrinkage rate of the fiber. In crimp contraction, crimp force is also an important factor, but in order to remarkably express the characteristics of the present invention,
The higher the crimping power, the better, but it is usually 1 mg / d, preferably 5 mg / d, more preferably 10 mg / d.

The fiber of the present invention is a composite fiber composed of a high shrinkage component and a low shrinkage component, and by heat treatment such as boiling water treatment,
Crimp develops in each fiber. In order to obtain the desired texture, the number of crimps is usually 5 to 100 pcs / inch, preferably 10 to 70 pcs / inch, and more preferably 15 to 5 pcs.
It is 0 / inch.

As the variation in the number of crimps between the filaments after the boiling water treatment, it is preferable that the variation rate is 200% or more. Due to this, many small natural voids are formed between the fibers so that there are voids between the filaments with a small number of crimps and the filaments with a large number of crimps even after becoming a cloth, and it is extremely close to silk. Creates a feeling of dullness and a feeling of surface.

The variation rate is obtained by the following equation, where the minimum value of the crimp rate of each filament is C _m and the maximum value thereof is C _M.

(Variation) = C _M / C _m × 100 (%)

The high shrinkage polyester component (hereinafter abbreviated as A component) used in the present invention is a polyester having a large heat shrinkage property, and a modified polyester is usually used. For example, when an aromatic polyester comprising a dicarboxylic acid component containing terephthalic acid or 2,6-naphthalenedicarboxylic acid as a main component and a glycol component containing ethylene glycol as a main component is produced by a known method, it is generally used as a third component. formula

[0035]

[Chemical 1] (In the formula, R represents a hydrogen atom or an alkyl group such as methyl, ethyl, n-propyl, iso-propyl, n-butyl, and t-butyl groups.) Isophthalic acid or an aliphatic ester thereof,
And / or obtained by copolymerizing bisphenol A
It

The addition amount of the third component to be copolymerized with the component A is usually preferably 3 to 20 mol%, more preferably 5 to 15 mol%. When the addition amount of the third component is within this range, sufficient shrinkage performance is obtained, sufficient bulkiness,
It is preferable because it can produce a feeling of dullness. In particular, a compound having the structure of Chemical formula 1 has the same or slightly larger amount of bispheno
By using a modified polyester that copolymerizes
The Tg (glass transition point) of the polymer is increased, and the heat resistance, dyeing fastness and light fastness of the fiber itself can be improved, which is more preferable. By increasing the Tg of the polymer, the linear shrinkage of the fiber is kept lower than that of the conventional heterogeneous-shrink mixed yarn in the fiber manufacturing stage as described above, and the thermal stability is improved. Sufficient heat setting can be performed, and good crimps can be developed by dry heat treatment at 160 to 200 ° C., preferably 170 to 190 ° C. at the final processing stage of the fabric.

The low shrinkage polyester component (hereinafter abbreviated as B component) used in the present invention has a lower boiling yield than the polyester component used as the A component, and therefore has a small modification rate. For example, a dicarboxylic acid component containing terephthalic acid or 2,6-naphthalenedicarboxylic acid as a main component,
When an aromatic polyester comprising a glycol component containing ethylene glycol as a main component is produced by a known method, the compound is polymerized as it is without adding the third component, or a compound to be copolymerized with the A component is added to the A component. It is usually 3 mol% or more less than the blending amount, preferably 5 to 1
The copolymerized polyester is reduced by 0 mol%.

When a polyester obtained by copolymerizing the third component with both the A component and the B component is used, if the difference in the addition amount of the A component and the B component is less than 3 mol%, the shrinkage characteristics of the A component and the B component are reduced. A sufficient difference in shrinkage and a difference in crimping ratio due to the difference in the above can not be obtained, and the desired performance and texture cannot be sufficiently exhibited.

Pigments, matting agents, fluorescent whitening agents, ultraviolet absorbers, antioxidants, antistatic agents, organic amines, organic carboxylic acid amides, etc. are produced during the production or spinning of the polyesters of the A and B components. You may use various things, such as an ether bond inhibitor, as needed.

The joining ratio (weight ratio) of the A component / B component in the multifilament assembly is preferably 2.5 /
1-1 / 1, more preferably 2/1 to 1.2 / 1.
When the bonding ratio of the A component / B component is within this range, a fabric having an excellent feeling of fluffiness and a soft surface touch can be obtained.

The reason why it is preferable to set the ratio of the component A and the component B is as follows. The ratio of the A component and B component and the structure of their lamination are different between the filaments constituting the fiber, and especially when the ratio of the B component (low shrinkage component) is large and the number of layers is small, the number of crimps also shrinks. The rate is also small, and these filaments float on the surface of the cloth in the cloth and generate minute fluff. On the other hand, in the case of filaments containing a large amount of component A (high shrinkage component), the shrinkage rate increases with the number of crimps, and these filaments sink inside the fabric and contribute to the development of firmness, stiffness, and fluffiness of the fabric, and the filament inside becomes minute. Develop dispersed voids.

At this time, since the ratio of the high shrinkage component (A) is large, the number of fibers sinking inside the fabric is large, and the fibers floating on the surface of the fabric are small. You get a touch.

The term "bonding ratio" as used herein means the average value of the area occupied by the A component and B component in the cross section of the fiber in all filaments in the fiber, and the A component and B component are measured by separate gear pumps during spinning. It can be controlled easily.

As a method for forming a laminated structure of A component and B component on each filament, the method conventionally proposed by us can be preferably used. For example, a kneading type distribution plate disclosed in JP-B-47-9533 and a static kneading element disclosed in JP-A-59-100717 can be exemplified. As the static kneading element, for example, a "static mixer" manufactured by Kenix, an ISG mixer manufactured by ROSS, a mixing element manufactured by Sruzer, or the like can be used.

The polymer flow passing through such a static kneading element is divided into 2 k powers where k is the number of elements. Usually, 1 to 4 static kneading elements are used here. Both A and B components are laminated in 2 to 16 layers by this element. A polymer melt in which a plurality of both components A and B are laminated is extruded into the air through a large number of spinning discharge holes to form filaments. Therefore, each filament is composed of both A and B components, and is usually 1 to 16 layers, preferably 2 to 10 layers, and more preferably 3 to 7 layers. When the number of layers is large, fluctuations between shrinkage characteristics and crimp characteristics between filaments are small, and it is difficult to obtain desired texture and performance.

In the spinning, a mixture obtained by mixing the above-mentioned two kinds of polymers into a multilayer by a static kneading element incorporated in the die is discharged from the fine holes of the die and wound. The winding method is
It is possible to use a combing method at a speed of up to about 1500 m / min, a POY method of about 3000 m / min, or a high-speed spinning (HOY) method of 5000 m / min or more. The wound fiber is subsequently drawn. Also, in the spinning stage, draw at the same time (SP
Of course, D) is also possible.

By using such a static kneading element, the ratio of the A component / B component and the laminated structure of each filament are greatly different as shown in FIG. 1, but such a polymer in the fiber axis direction of each filament is used. The ratio and the laminated structure were hardly changed, and the deterioration of operability, which was a fundamental problem in the conventional polymer blend spinning, could be greatly improved.

For the stretching, a combination of a heating roller and a heating plate which is generally used generally can be preferably used, but stretching by a plurality of heating rollers may be used. In the case of a combination of a heating roller and a heating plate, drawing is performed with the heating roller and heat setting is performed with the heating plate, so that the yarn quality and crimping characteristics that match the purpose are provided. For example, the stretching temperature is usually 60-
The temperature is 140 ° C, preferably 65 to 120 ° C, more preferably 70 to 100 ° C. The temperature of the heating plate is usually set higher than the drawing temperature by 10 to 50 ° C., but in order to keep the total shrinkage rate and linear shrinkage rate of the fiber at the target values, it is usually 1
20-180 degreeC, Preferably it is 120-160 degreeC.
After the drawing, it is possible to improve the appearance of the crimp by further drawing at a draw ratio of at most about 1.1 times while heating in the range of the drawing temperature to the set temperature. By treating under such conditions, the linear shrinkage of the fiber can be suppressed and the crimp shrinkage can be improved.

By using the fiber of the present invention, a woven or knitted fabric which is normally used without using a different shrinkage mixed yarn or a different shrinkage composite processed yarn, using a single yarn, and without forming a special woven structure. Even in the same tissues as above, the desired softness and fluffiness are exhibited, and the touch due to the delicate fluff on the surface can be expressed. In other words, there is no need to take complicated thread usage, weaving structure, processing means and conditions, which were used in the conventional sensibility synthetic fiber and new synthetic fiber, and a great advantage is that a new sense of fabric can be obtained at low cost. is there. Of course, by using it as a component of the different shrinkage mixed yarn or the composite textured yarn, or by making a more complicated weave structure, it is possible to express a higher degree of texture and touch.

The processing of woven or knitted fabric can be carried out in the same manner as the processing of ordinary fibers. For example, it is a series of steps such as scouring, alkali reduction, relaxation, dyeing, heat setting and the like, and if necessary, resin processing is performed. Further, the fiber of the present invention may be used alone, or may be used as a mixture with other fiber if necessary.

[0051]

The present invention will be described in detail with reference to the following examples. In the examples, "parts" means "parts by weight" unless otherwise specified, and "%" means "% by weight" unless otherwise specified. The intrinsic viscosity [η] was determined by a conventional method at 20 ° C. in a mixed solvent of phenol / tetrachloroethane = 6/4 (weight ratio). Further, the scanning electron microscope (hereinafter referred to as SEM) measurement was performed with a scanning electron microscope manufactured by Akashi Seisakusho. The number of crimps was converted to the number per 1 inch from SEM observation or a micrograph taken by a stereomicroscope manufactured by Olympus.

Production of Composite Yarn (1) As the low shrinkage component (component B), a usual polyethylene terephthalate having a [η] = 0.64 (hereinafter usually referred to as polyester) was used. Also, high shrinkage component (A component)
A modified polyester obtained by copolymerizing polyethylene terephthalate with 5 mol% of isophthalic acid as an acid component and 5.5 mol% of bisphenol A (2EO adduct) was used.

Both components have a joining ratio of A component and B component of 1.
The temperature is 290 in the extruder so that it becomes 5/1.
After melting at ℃, weigh with separate gear pumps and send to the spinneret. Inside the spinneret, A, B is passed through a static kneading element (3 Kenics mixing elements).
Both components are mixed to have a multi-layered structure and then 36
1,500 m / s for melt spinning from Y-shaped spinning pores of equal length
It was wound at a speed of minutes to obtain an undrawn yarn. The cross section of the obtained undrawn yarn had a substantially triangular shape with rounded corners. The yarn was drawn with a roller heater at 75 ° C. at a draw ratio of 3.0 times and a drawing speed of 750 m / min, and was heat set on a hot plate (PLH) shown in Table 1, and then 75 denier (hereinafter referred to as d) / 36. A multifilament of filaments (hereinafter referred to as f) was obtained. These yarns were designated as F-1 to F-5 (Table 1).

When the cross section of the fiber was observed with a microscope, it was a composite fiber having a multi-layer structure of at least two layers, and at most four layers as shown in FIG. Also, the characteristic is the composite shape of each fiber (composite ratio, composite shape, multilayered state, etc.)
Are different things. Table 1 shows the shrinkage and crimp characteristics of the obtained drawn yarn.

Table 1 shows the total shrinkage percentage, linear shrinkage percentage, crimp shrinkage percentage, and ratio of the crimp shrinkage percentage to the total shrinkage percentage (winding yield) of the various drawn yarns after boiling water treatment. Further, the surface moisture of the fiber sample after the boiling water treatment was sufficiently wiped off, air-dried, and then heat-treated at 180 ° C. for 3 minutes in a warm air dryer, the total shrinkage ratio and the crimp shrinkage ratio are shown together. The total shrinkage and crimp shrinkage after dry heat treatment were measured and calculated in the same manner as after boiling water treatment.

Production of Composite Yarn (2) Melting from 36 Y-shaped spinning pores of equal length at a spinning temperature of 290 ° C. and a spinning speed of 1500 m / min using a normal polyester of [η] = 0.64. Spun The yarn was drawn at a draw ratio of 3.0 times at a draw speed of 750 m / min with a roller heater at 85 ° C. and set with a plate heater at 150 ° C. to obtain 75 d / 36 f multifilament F-6. After the obtained drawn yarn was treated with hot water, the crimp shrinkage value or the linear shrinkage value was obtained. The yarn after shrinking with boiling water was a normal fiber with no crimp. The total boiling yield and the linear shrinkage were both 7.6%, and there was no crimp shrinkage.

Production of composite yarn (3) Melting from 18 equal-length Y-shaped spinning pores at a spinning temperature of 290 ° C. and a spinning speed of 1200 m / min using a normal polyester of [η] = 0.64. Spun The cross section of the obtained undrawn yarn had a substantially triangular shape with rounded corners. The yarn was drawn with a roller heater at 84 ° C. at a draw ratio of 3.2 times and a drawing speed of 730 m / min and set with a plate heater at 145 ° C. to obtain a 37.5 d / 18 f multifilament. Further, a modified polyester obtained by copolymerizing 5 mol% of bisphenol A (2EO adduct) as an alcohol component of [η] = 0.64 was used, and 18 pieces or the like at a spinning temperature of 285 ° C. and a spinning speed of 1200 m / min. Melt spinning was performed from a long Y-shaped spinning pore. The cross section of the obtained undrawn yarn had a substantially triangular shape with rounded corners. The yarn was drawn at a draw ratio of 3.2 times at a draw speed of 730 m / min with a roller heater at 84 ° C. and set with a plate heater at 90 ° C., and then at 37.5 d.
A / 18f multifilament was obtained.

Two of these two kinds of fibers were further combined by a rewinding machine to form a 75d / 36f different shrinkage mixed fiber F-7.

In order to evaluate the heat shrinkage characteristics of the fibers used in the mixed fiber, each of the drawn yarns before compounding was subjected to hot water treatment, and then the crimp shrinkage ratio or the linear shrinkage ratio was obtained. In each case, the yarn after shrinking with boiling water was a normal fiber with no crimp.
The total boiling yield and linear shrinkage of the yarn on the low shrinkage side are both 8.4.
%, There is no crimp shrinkage, and the total boiling yield on the high shrinkage side is 36.5.
%Met.

Examples 1 to 3, Comparative Examples 1 to 4 Fibers obtained according to the present invention (a plain weave (taffeta) using the drawn yarns F-1 to F-7 as warp and weft, woven and scoured at 60 ° C. for 15 After using the jet dyeing machine to reduce the alkali weight by 1%,
After relaxing at 30 ° C, it was set by dry heat at 180 ° C. The texture of the finished fabric was evaluated by the touch of an expert. The evaluation was carried out for a tight fluffy feeling and soft touch on the surface. Particularly excellent ones were marked with ⊚, excellent ones with ◯, slightly inferior ones with Δ, and inferior ones with x. Further, the same evaluation was performed for the comprehensive evaluation. The results are shown in Table 2.

[0061]

[Table 1]

[0062]

[Table 2]

Production of Composite Yarn (4) Stretched yarns F-8 and F-9 were obtained in the same manner as in Example 1 except that the ratios of the A component and the B component were 1/1 and 1 / 1.5. It was Table 3 shows the shrinkage characteristics of the drawn yarns F-8 and F-9.

[0064]

[Table 3]

Example 4 and Comparative Example 5 Next, the drawn yarns F-8 and F-9 were made into a plain weave in the same manner as in Example 2 and the same evaluation results are shown in Table 4. The woven fabric using the drawn yarn of the present invention showed excellent quality of silk filament woven fabric.

[0066]

[Table 4]

[0067]

Industrial Applicability The random latent crimped yarn of the present invention has good latent shrinkability and latent crimpability, and all of them have random variations among filaments in the fiber. In the case of using a cloth, a cloth having a feeling of tight fluffiness and a feeling very close to that of a silk filament woven fabric that realizes a refreshing touch due to delicate surface fluff can be obtained.

In particular, the concept is different from that of the conventional different-shrinkage mixed fiber in which high-low shrinkage fibers are mixed, and the shrinkage ratio of the fiber is suppressed to utilize the crimpability of the fiber. In other words, due to the slightly different shrinkage ratio and the greatly different crimp ratio between the filaments that make up the fiber, the air layer contained in the yarn is distributed in a large amount and evenly. There is no need for delicate temperature adjustment or tension adjustment as in the above, moreover, quality defects such as shrinkage spots, dyeing spots, and grain spots are less likely to occur, and the workability such as sewing can be greatly improved. Have a certain merit.

[Brief description of drawings]

FIG. 1 shows an example of a cross-sectional morphology of a fiber of the present invention.

FIG. 2 is an example of a SEM photograph (magnification = 20 times) of a crimp development state after boiling water treatment, showing a fiber shape.

[Explanation of symbols]

a. High shrinkage component b. Low shrinkage component

Continuation of the front page (56) References JP-A-8-269856 (JP, A) JP-A-4-18132 (JP, A) JP-A-59-100717 (JP, A) JP-A-62-45721 (JP , A) JP 8-246277 (JP, A) JP 7-3554 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) D02G 1/00-3/48 D02J 1/00-13/00 D01F 8/14

Claims (4)

(57) [Claims] 1. A multifilament comprising two kinds of polyester components having different shrinkage ratios and having a multilayer laminated structure continuous in the fiber axis direction, wherein the total boiling yield of fibers by boiling water treatment is 20 to 40%, and linear shrinkage occurs. The rate is at most 20%,
Moreover, the ratio of the crimp contraction rate to the total boiling yield of the fiber is 50 to
90% polyester conjugate fiber. 2. The ratio of the component (A) having a higher shrinkage ratio to the component (B) having a lower shrinkage ratio is A / B = 1/1 to 2.5 /
The polyester composite fiber according to claim 1, which is 1 (weight ratio). 3. The fluctuation rate of the number of crimps after the boiling water treatment of the fiber is 2
The polyester composite fiber according to any one of claims 1 to 2, which is at least 00%. 4. The fiber according to claim 1, which has a crimp shrinkage of 40% or more after dry heat treatment.