JP2002227035A - Polylactic acid fiber structure having excellent chromatic color development and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a polylactic acid fiber structure having excellent chromatic color development and high heat resistance and to provide a method for producing the same. SOLUTION: This polylactic acid fiber structure obtained by using a polylactic acid fiber composed of a blend of a poly(L-lactic acid) and a poly(D- lactic acid) at least as a part is dyed with a chromatic color dye.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polylactic acid fiber structure having high heat resistance and excellent chromatic color development.

[0002]

2. Description of the Related Art Polylactic acid fiber has recently attracted particular attention as a practical biodegradable fiber because it is easily decomposed by the action of microorganisms in soil and water and has a relatively high melting point and crystallinity. . In addition, polylactic acid fibers have polymer properties that are superior to other synthetic fibers in dyeing and coloring properties, so their use is expected not only in the industrial and material fields, but also in the garment field where coloring properties can be fully utilized. Have been.

On the other hand, aromatic polyesters typified by polyethylene terephthalate have excellent fiber properties such as strength, heat resistance, and wash-and-wear properties, but have a high refractive index because they have an aromatic ring in the structure. However, there is a problem that the coloring and coloring properties are poor. This problem is particularly acute in applications that require vivid chromatic coloring,
For example, various studies have been made on, for example, cationic dyeing by modifying a polymer, and improving the color developability by lowering the glass transition temperature Tg. However, even with these methods, there is a limit to the improvement in color development, and in some cases, there is a problem that the color fastness such as light fastness is reduced. Moreover, with these methods,
Since polymer modification is indispensable, there is also a disadvantage that cost is high and versatility is lacking.

[0004] The inventors of the present invention required that polylactic acid fibers containing poly-L-lactic acid as a main component, which has a sharp chromatic coloring property for women's clothing, formal wear, sportswear, and the like, be used. Has been studied for use in clothing applications. In this case, certainly a very general approach,
A sharp chromatic vivid color development that could not be achieved with an aromatic polyester fiber such as polyethylene terephthalate can be achieved. However, the melting point of so-called homopolylactic acid such as poly-L-lactic acid and poly-D-lactic acid is at most 160-180.
It is not suitable for use where it is desired to iron after cleaning, such as formal wear, because it has only a temperature of ° C. That is, the heat resistance of these homopolylactic acid fibers is not sufficient, and their use is actually limited.

On the other hand, it is known that a stereocomplex crystal comprising a mixture of poly-L-lactic acid and poly-D-lactic acid has a higher melting point than a crystal of homopolylactic acid alone. Known techniques for applying this technique to fibers include JP-A-63-264913 and JP-A-63-2410.
No. 24, Seni Gakkai Preprints 1989, etc.
In any case, there is a problem that the fiber does not have practical fiber strength, or the heat resistance is insufficient even if it has practical fiber strength. Not at all.

[0006] As described above, polylactic acid fibers having high heat resistance in the field of emphasizing coloring properties such as apparel applications do not exist in spite of being desired.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide a polylactic acid fiber structure having heat resistance and excellent chromatic color development, and a method for producing the same.

[0008]

Means for Solving the Problems The present invention has the following structure to solve the above-mentioned problems.

That is, a polylactic acid fiber comprising at least a portion of a polylactic acid fiber comprising a blend of poly L-lactic acid and poly D-lactic acid, and having a chroma C * value of 20 or more. Things.

Further, a polylactic acid fiber structure using at least a portion of a polylactic acid fiber comprising a blend of poly L-lactic acid and poly D-lactic acid is dyed with a chromatic dye. This is a method for manufacturing a structure.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Polylactic acid fibers have excellent dye dispersibility as compared with other synthetic fibers. Therefore, when dyed, it does not become a dull color and can express a vivid and clear chromatic color. The present invention focuses on the special and excellent dyeing and coloring properties of such polylactic acid fibers, and at the same time diligently studies a blending technique of poly-L-lactic acid and poly-D-lactic acid in order to impart heat resistance. As a result, a polylactic acid fiber structure having high heat resistance and excellent chromatic coloring was obtained. Hereinafter, the present invention will be described in detail.

The polylactic acid fiber of the present invention is characterized by comprising a blend of poly L-lactic acid and poly D-lactic acid.

As a method for producing poly-L-lactic acid and poly-D-lactic acid, lactide, which is a cyclic dimer, is first produced from L-lactic acid or D-lactic acid as a raw material, followed by ring-opening polymerization. A lactide method, a one-stage direct polymerization method in which the raw material is directly dehydrated and condensed in a solvent, and the like, are not limited thereto, and a known method can be appropriately employed.

The poly-L-lactic acid used in the present invention is a polymer containing L-lactic acid as a main monomer component, and a copolymer poly-L containing not more than 15 mol% of a D-lactic acid component in addition to L-lactic acid.
-Lactic acid may be used, but from the viewpoint of enhancing the formation of stereocomplex crystals, the D-lactic acid component in the poly-L-lactic acid is preferably as small as possible, and the poly-L-lactic acid containing the D-lactic acid component at 3 mol% or less is preferable. It is more preferred to use

Similarly, the poly-D-lactic acid used in the present invention is D-lactic acid.
-A polymer containing lactic acid as a main monomer component, and D-
In addition to lactic acid, a copolymerized poly D-lactic acid containing 15 mol% or less of an L-lactic acid component may be used. However, from the viewpoint of enhancing the formation of stereocomplex crystals, the L-lactic acid component in the poly D-lactic acid is It is preferable that the amount of L-lactic acid is as small as possible.
It is more preferable to use poly D-lactic acid containing at most mol%.

Further, the poly-L-lactic acid and / or poly-D-lactic acid used in the present invention may be copolymerized with another ester-forming monomer component as long as the effects of the present invention are not impaired. As copolymerizable monomer components,
In addition to hydroxycarboxylic acids such as glycolic acid, 3-hydroxybutyric acid, 4-hydroxybutyric acid, 4-hydroxyvaleric acid, and 6-hydroxycaproic acid, ethylene glycol, propylene glycol, butanediol, neopentyl glycol, polyethylene glycol, glycerin, Compounds having a plurality of hydroxyl groups in a molecule such as pentaerythritol or derivatives thereof, succinic acid, adipic acid, sebacic acid, fumaric acid, terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, 5-sodium sulfo Compounds containing a plurality of carboxylic acid groups in the molecule, such as isophthalic acid and 5-tetrabutylphosphonium sulfoisophthalic acid, and derivatives thereof are exemplified.

The weight average molecular weight of the above-mentioned poly L-lactic acid and poly D-lactic acid should be at least 50,000, preferably at least 100,000, and more preferably 100,000 to 400,000. If the weight average molecular weight is less than 50,000, the strength physical properties of the fiber are undesirably reduced. On the other hand, if it exceeds 400,000, the melt viscosity becomes too high and melt spinning may be difficult, which is not preferable.

The poly-L-lactic acid and poly-D-lactic acid used in the present invention may contain components other than the main polymer as long as the effects of the present invention are not impaired. For example,
To reduce the melt viscosity, polycaprolactone, polybutylene succinate, aliphatic polyesters such as polyethylene succinate, polyethylene glycol,
Aliphatic polyether polymers such as polypropylene glycol and poly (ethylene-propylene) glycol copolymer can be used as an internal plasticizer or as an external plasticizer. Further, inorganic fine particles and organic compounds may be added as necessary as an ultraviolet stabilizer, a matting agent, a deodorant, a flame retardant, a yarn friction reducing agent, an antioxidant or a coloring pigment.

The strength of the polylactic acid fiber in the present invention is not particularly limited, but it is intended to reduce the breakage of yarn breakage during weaving and to prevent a decrease in product strength due to a decrease in tear strength and burst strength of woven fabric and knitted fabric. From the viewpoint, preferably 2c
It is preferably at least N / dtex, more preferably at least 3 cN / dtex, even more preferably at least 4 cN / dtex.

The boiling water shrinkage rate of the polylactic acid fiber in the present invention is not particularly limited, but is preferably 15% or less from the viewpoint that the fabric can be easily tentered even when subjected to hot water processing such as scouring and dyeing. It is desirable that Further, from the viewpoint of preventing texture hardening due to excessive shrinkage, when used as a normal cloth, the boiling water shrinkage ratio is 2 to 10
%, More preferably 3 to 8%.

The method for spinning the polylactic acid fiber of the present invention is not particularly limited, and any known method may be appropriately employed. However, industrially highly efficient production can be carried out. The melt spinning method is preferred from the viewpoint that a solution in which D-lactic acid is blended can be stably and uniformly formed.

The polylactic acid fiber of the present invention is composed of a poly-L-lactic acid single crystal and a poly-D-lactic acid obtained by DSC measurement from the viewpoint of improving heat resistance by forming a stereo complex of poly-D-lactic acid and poly-L-lactic acid. It is preferable that the ratio ΔHh / ΔHl of the sum ΔHl of the heat absorption based on the crystal melting of the single crystal and the heat absorption ΔHh of the stereocomplex crystal composed of poly L-lactic acid and poly D-lactic acid based on the crystal melting is 10 or more. From a similar viewpoint, ΔH
h / ΔHl is more preferably 20 or more, and further preferably 30 or more. In the case of a polylactic acid fiber composed of a blend of homopoly L-lactic acid and homopoly D-lactic acid, the peak temperature of ΔHl is around 160 to 180 ° C, and the peak temperature of ΔHh is 210 ° C to 230 ° C.
It is often present nearby. ΔHh / ΔHl is 1
If it is less than 0, the formation of stereocomplex crystals is insufficient, so that the fibers are thermally deformed at the melting temperature of the poly-L-lactic acid single crystal or the poly-D-lactic acid single crystal, resulting in insufficient heat resistance. .

The blend of poly-L-lactic acid and poly-D-lactic acid as referred to in the present invention can be produced by a known method without any particular limitation. For example, it can be produced by the following method.

The polylactic acid fiber of the present invention can be obtained by subjecting a blend of poly L-lactic acid and poly D-lactic acid to ordinary melt spinning. As a blending method of poly-L-lactic acid and poly-D-lactic acid, for example, there is a method of subjecting a chip blend (dry blend) of poly-L-lactic acid chips and poly-D-lactic acid chips to melt spinning. Is
A conventional melt extruder such as a pressure melter type or a single-screw or twin-screw extruder can be used, but from the viewpoint of easily kneading poly-L-lactic acid and poly-D-lactic acid to easily form stereocomplex crystals. A shaft or twin shaft extruder type is preferred. Furthermore, a method of incorporating a static kneader in the polymer channel, a chip blend of a poly-L-lactic acid chip and a poly-D-lactic acid chip is melted and kneaded by a twin-screw extruder-type kneader to form chips. A method of subjecting the pre-kneaded chips to melt spinning is preferred. Alternatively, poly L-lactic acid and poly D-lactic acid may be mixed after being melted by separate melt extruders. In any of the above cases, kneading due to shear stress when passing through the filtration layer or the spinneret is expected. Particularly, when the poly-L-lactic acid and the poly-D-lactic acid are melted and mixed in separate melt extruders, the kneading is performed. It is preferable to incorporate a static kneader after mixing from the viewpoint of strengthening.

The blend ratio of poly L-lactic acid and poly D-lactic acid used in the polylactic acid fiber of the present invention is such that poly L-lactic acid: poly D-lactic acid is between 30:70 and 70:30. However, from the viewpoint of promoting the formation of stereocomplex crystals and improving the content ratio, 40: 6 is preferable.
More preferably between 0 and 60:40, 4
More preferably, it is between 7:53 and 53:47.

The above blend of poly-L-lactic acid and poly-D-lactic acid is melted by an extruder-type or pressure-melter-type melt extruder, weighed by a metering pump, and filtered in a spinning pack or the like. After receiving
It is discharged from a base having a desired base shape and the number of bases.
The discharged yarn is cooled and solidified by passing it through a gas having a temperature lower than the melting point of the polymer, and then oiled and taken off.However, by increasing the molecular orientation during spinning, the polylactic acid stereocomplex crystal Is preferably formed at a rate of 300 m / min or more, since it is easy to form. From the same viewpoint, the spinning draft is preferably 50 or more. In addition, it is preferable to use an air current suction device on the upstream side of the cooling or in the cooling section in order to remove sublimates from the discharged yarn. In addition, just below the spinning,
Before cooling and solidifying, it is preferable to install a heating zone to heat the yarn to a temperature equal to or higher than the melting point of the polymer from the viewpoint of increasing the strength of the fiber. For cooling, any of annular chimney and uniflo chimney can be used. The drawn undrawn yarn is then subjected to drawing. Either a two-step method of winding once before drawing or a direct spin drawing method of continuously drawing without winding after spinning may be used, but from the viewpoint of productivity, the direct spin drawing method is used. Is preferred.

The stretching step may be performed in one step or in two or more steps, but it is preferable to perform two or more steps in view of increasing strength. On the other hand, if the draw ratio is too high, the whitening phenomenon of the fiber occurs and the strength is reduced. Therefore, it is preferable to set the draw ratio so that the whitening phenomenon of the fiber does not occur. Any method may be used as the stretching heat source, such as a hot roller, a contact hot plate, a non-contact hot plate,
A heat medium bath, pins, etc. may be used.

After the stretching, a heat treatment is preferably performed at a temperature lower by about 10 to 120 ° C. than the melting point of the polymer before winding. Any method such as a hot roller, a contact hot plate, and a non-contact hot plate can be used for the heat treatment. From the viewpoint of dimensional stability, it is preferable that a relaxation treatment of 0 to 20% is performed subsequent to the heat treatment.

The polylactic acid fiber of the present invention may have a round cross section or a modified cross section such as a flat, 3- to 8-leaf, C-shaped, H-shaped or hollow shape, or a core-sheath type containing at least polylactic acid as a component. An eccentric core-sheath type, a side-by-side type, a split fiber split type, or a sea-island type composite fiber of a type that elutes one component may be used. In addition to normal flat yarn, false twisted yarn, strong twisted yarn, Taslan processed yarn, thick and thin yarn,
It may be a filament yarn such as a mixed fiber, or a fiber of various forms such as a staple fiber, a tow, or a spun yarn.

The fiber structure of the present invention comprises the above-mentioned polylactic acid fiber of the present invention alone or in combination with other fibers.
It is a fiber structure subjected to processing including dyeing, and may be a thread form such as a sewing thread, an embroidery thread, a string, a fabric form such as a woven fabric, a knitted fabric, a nonwoven fabric, a felt, or a coat,
Sweaters, other outerwear, underwear, pantyhose, socks, lining, interlining, sports clothing and other clothing products, curtains,
Various textile products such as carpets, chairs, bags, furniture, wall materials, products for daily life such as various belts and slings, products for industrial materials such as canvas, net, rope, heavy cloth, and artificial leather products. including. In particular, the polylactic acid fiber of the present invention is characterized by being excellent in both color developability and heat resistance, and is therefore suitable for use in clothing such as woven and knitted fabrics.

Even when the polylactic acid fiber is mixed with other fibers, it is preferable to use a method utilizing the excellent chromatic coloring of the polylactic acid fiber. When mixed as a fabric, for example, the mixing ratio of the polylactic acid fiber of the present invention is preferably 30% or more, and the other mixed fiber is dyed with an appropriate dye in a chromatic color similarly to the polylactic acid fiber. It is preferred to use. Other fibers include, but are not particularly limited to, cellulose fibers such as cotton and hemp, wool, silk, rayon, acetate, and fibers such as polyester, nylon, acrylic, vinylon, polyolefin, and polyurethane.

Examples of the blending mode include various combinations with a fiber structure composed of other fibers, as well as blended yarns with other fibers, composite false twisted yarns, blended yarns, long and short composite yarns, fluid processed yarns, covering yarns. Examples thereof include ply twist, cross weaving, cross knitting, pile woven and knitted fabric, mixed cotton wadding, mixed nonwoven fabric of long fibers and short fibers, and felt.

The fiber structure of the present invention is characterized in that the C * value is 20 or more. The C * value means the saturation defined by (a * ² + b * ² ) ^1/2 in the L * a * b * system color display. The larger the value, the less dullness and sharpness It looks bright and chromatic. In the present invention, the C * value needs to be 20 or more from the viewpoint of vivid chromatic coloring. Also, if a sharper color development is desired, it cannot be unambiguously defined depending on the hue or lightness.
The value is preferably 30 or more, more preferably 40 or more,
Most preferably, it should be 50 or more in many cases. Further, when the L * value is 20 or more, sharpness can be maintained without being too dark, and when the L * value is 50 or less, the colorability is good without being too light. It is.

The fiber structure of the present invention is obtained by dyeing a polylactic acid fiber structure using at least a portion of a polylactic acid fiber comprising a blend of poly L-lactic acid and poly D-lactic acid with a chromatic dye. Can be manufactured.

The chromatic dye of the present invention is defined as having a chroma (C * value) of 20 when the polylactic acid fiber of the present invention is dyed.
It means the dye described above. That is, as long as the C * value is 20 or more, for example, a dye containing two or more kinds of different kinds of dyes may be used. In addition, as a dye that can suitably dye polylactic acid fibers, disperse dyes may be mentioned, but in the case of a mixed fiber structure with other fibers, other dyes may be used in addition to the disperse dye as necessary. good. As a disperse dye,
There is no particular limitation, and commercially available ones can be appropriately used. For example, Miketon Polyester dye (Mitsui BASF)
Dye Co., Ltd.), Miketon Fast Dye (Mitsui BASF Dye Co., Ltd.), Dispersol Dye (Mitsui BASF Dye Co., Ltd.)
), Palanil Dye (Mitsui BASF Dye Co., Ltd.), Sumikar
on dye (Sumitomo Chemical Co., Ltd.), Kayalon Polyester dye (Nippon Kayaku Co., Ltd.), Dianix dye (Dystar Co., Ltd.)
), Terasil dye (manufactured by Ciba Specialty Chemicals), Foron dye (manufactured by Clariant) and the like.

The dye concentration is not particularly limited, but in order to obtain a color with high saturation such as a C * value of 20 or more after dyeing,
In many cases, it is preferably 0.1 to 30% owf, and more preferably 0.5 to 10% owf. If it is less than 0.1% owf, the color tone will be insufficient, and if it is more than 30% owf, the color will be extremely dark and the saturation will be reduced.

The technique for dyeing is not particularly limited, and known techniques such as dip dyeing, printing, and thermosol dyeing can be appropriately employed. However, from the viewpoints of cost, versatility, and quality of dyed fabric, dip dyeing or printing can be performed. preferable.

In the case of dip dyeing, an ordinary machine such as a high-pressure jigger dyeing machine or a liquid jet dyeing machine can be used. As the dyeing solution, a solution prepared by appropriately preparing a pH adjuster, a surfactant, and the like in addition to the dye and water is used. Regarding the dyeing temperature, the temperature is preferably 90 to 150 ° C, more preferably 100 to 140 ° C, and most preferably 105 ° C, as the temperature at which the dye can sufficiently diffuse into the fiber and the strength of the fiber hardly decreases due to hydrolysis. ~ 135 ° C is good.

In the case of textile printing, it can be dyed by a usual method such as hand print, screen print, rotary print, ink jet print and the like. As the ink, a fibrous structure pretreated with a water-soluble polymer or the like using a dye and water in addition to a wetting agent, an anti-drying agent, a pH adjusting agent, a preservative, a fastness improver, etc. After that, steam processing is performed. Steam processing is 100-12
Either saturated steam at 0 ° C or heated steam at 120 to 150 ° C may be used.

Before dyeing, 50 ° C to 100 ° C, pH7
Scouring under weak alkaline conditions of ~ 12 and / or 50
Weight reduction processing under alkaline conditions of １００100 ° C. and pH 9〜14 can be carried out as required. Further, after the dyeing process, reduction washing in the presence of a reducing agent at pH 3 to 12 can be performed if necessary. Further, a known resin coating may be performed to improve the color developing property and to impart other functions.

[0041]

The present invention will be described in more detail with reference to the following examples. Each characteristic value in the examples was obtained by the following method.

A. Strength (cN / dtex) Measured using a “Tensilon” tensile tester type manufactured by Orientec Co., Ltd. under the conditions of a sample length of 25 cm and a tensile speed of 30 cm / min.

B. ΔHl, ΔHh (J / g) “SSC5200 / DSC12 manufactured by Seiko Instruments Inc.
It was determined from a DSC curve obtained by performing measurement at a heating rate of 10 ° C./min using a 0 ″ differential scanning calorimeter.

C. L * a * b * value The dyed fabric which was folded in two so as not to be transparent was subjected to L *, a under the conditions of a D65 light source and a viewing angle of 10 ° using a spectrophotometer “CM-3700d” manufactured by Minolta. * And b * were measured. The C * value was calculated by the following equation.

C * = (a * ² + b * ² ) ^1/2 D. Tear Strength (cN) Using a “Elmendorf Tear Strength Meter” manufactured by Daiei Kagaku Seiki Co., Ltd., set a test piece of 10 cm long x 6.5 cm wide, pull the cutter handle of the test machine to make a 2 cm cut. Was. The fan-shaped pendulum was dropped by pressing the drop button, and the remaining 4.5 cm of the test piece was torn, and the strength at this time was read. In the test, the vertical direction and the horizontal direction were repeated three times each, and the average value was taken as the tear strength (cN) of the fabric.

E. 200 ° C. heat resistance After an iron adjusted to 200 ° C. was brought into contact with a 10 cm square fabric for 30 seconds, the state of the fabric was observed.

：: The fabric shape before the treatment was maintained without heat fusion between the single yarns.

×: Thermal fusion between single yarns, thermal deformation or thermal fusion of the fabric was observed.

Example 1 A poly-L-lactic acid homopolymer (PLLA) having a weight average molecular weight of 120,000 and a poly-D-lactic acid homopolymer of 300,000 were chip-blended at a weight ratio of PLLA: PDLA = 50: 50. The mixture was dried under reduced pressure at 100 ° C. for 12 hours, melt-kneaded and formed into chips by a twin-screw kneading extruder to prepare a preliminary kneaded chip composed of PLLA and PDLA.

The pre-kneaded chips were dried under reduced pressure at 100 ° C. for 12 hours, and spun out from a 0.34D-0.50 L die hole at a spinning temperature of 260 ° C. by a pressure melter type melt spinning machine. The spun yarn was cooled by a chimney style at 25 ° C. and a temperature of 20 ° C., converged by applying an oil agent, and then taken out at 3000 m / min to obtain an undrawn yarn (122 dt).
ex-36f) was obtained.

The undrawn yarn was drawn using a hot roller type drawing machine at a drawing temperature of 90 ° C., a heat setting temperature of 120 ° C., a drawing ratio of 1.45 times, and a drawing speed of 800 m / min. A drawn yarn was obtained. The strength of the obtained drawn yarn was 3.9 cN / dtex, and the boiling water shrinkage was 9.
0%, which did not cause any problem in handling the fabric.

Using this drawn yarn, a twill fabric (2/2)
After scouring at 80 ° C. × 20 minutes, 150 ° C.
A dry heat setting was performed for 2 minutes. The woven fabric was dyed in a dyeing bath adjusted to the following conditions using a liquid jet dyeing machine.
C. × 60 minutes staining, followed by 0.5 g of caustic soda
/ L and an aqueous solution in which 0.2 g / l of hydrosulfite was dissolved, reduction washing was performed at 60 ° C for 20 minutes. The obtained dyed fabric had a warp yarn density of 40 yarns / cm and a weft yarn density of 40 yarns / cm.

As shown in Table 1, the C * value was 52.2, which is a sufficiently high value, and was excellent in chromatic coloring. The tear strength was also 920 cN, which was excellent in durability. Also, it had heat resistance of 200 ° C.

Dyeing conditions (dyeing) Dyeing temperature 120 ° C. Dyeing time 60 minutes Dye Kayalon Polyester Rubine BL-S 200 (manufactured by Nippon Kayaku Co., Ltd.) Dye concentration 2% owf Bath ratio 1:50 Bath pH 4.5 Example 2 A dyed fabric was obtained in the same manner as in Example 1 except that the dyeing conditions were changed to the following.

As shown in Table 1, the C * value was a sufficiently high value of 43.5, and the chromatic color development was excellent. The tear strength was 915 cN, which was excellent in durability. Also, it had heat resistance of 200 ° C.

Dyeing conditions (dip dyeing) Dyeing temperature 120 ° C. Dyeing time 60 minutes Dye Miketon Polyester Blue RSE (manufactured by Mitsui BASF Dye Co., Ltd.) Dye concentration 5% owf Bath ratio 1:50 Bath pH 4.5 Example 3 Woven tissue Was changed from twill to satin (five satin), and a dyed fabric was obtained in the same manner as in Example 1. The obtained dyed fabric had a warp yarn density of 79 yarns / cm and a weft yarn density of 39 yarns / cm.

As shown in Table 1, the C * value of the fabric is 50.
This was a sufficiently high value of 2 and was excellent in chromatic coloring. The tear strength was 880 cN, which was excellent in durability. Also, it had heat resistance of 200 ° C.

Example 4 A drawn yarn (84 dtex-36) obtained in the same manner as in Example 1
Using f), an interlock knitted fabric was prepared using a 24-gauge weft knitting machine. 130 ° C. × 6 with respect to this knitted fabric in a dye bath adjusted to the following conditions using a jet dyeing machine.
Staining was performed for 0 minutes, followed by reduction washing at 60 ° C. for 20 minutes.

As shown in Table 1, the C * value of the cloth was 46.
5, which was a sufficiently high value, and was excellent in chromatic coloring. The tear strength was also 1750 cN, which was excellent in durability. Also, it had heat resistance of 200 ° C.

Dyeing conditions (dip dyeing) Dyeing temperature 130 ° C. Dyeing time 60 minutes Dye Kayalon Polyester Rubine BL-S 200 (manufactured by Nippon Kayaku Co., Ltd.) Dye concentration 2% owf Bath ratio 1:50 Bath pH 4.5 Example 5 PLLA: PDLA = 50: 50 PLLA: PDLA
= 60:40, and a drawn yarn was obtained in the same manner as in Example 1. The strength of the obtained drawn yarn is 4.1 cN / d.
The tex and the boiling water shrinkage were 8.8%, and there was no problem in handling the fabric.

Using the drawn yarn, a dyed fabric was obtained in the same manner as in Example 1.

As shown in Table 1, the C * value was 51.7, which was a sufficiently high value, and was excellent in chromatic coloring. The tear strength was 930 cN, which was excellent in durability. Also, it had heat resistance of 200 ° C.

Example 6 A dyed fabric was obtained in the same manner as in Example 1 except that the dyeing method was changed to a hand print method under the following conditions.

As shown in Table 1, the C * value was 46.2, which was a sufficiently high value, and was excellent in chromatic coloring. The tear strength was also 860 cN, which was excellent in durability. Also, it had heat resistance of 200 ° C. Dyeing conditions (printing) Ink ・ Dye Kayalon Polyester Rubine BL-S 200 (Nippon Kayaku Co., Ltd.) 2 wt% ・ Glue Algintex M (10%) (Kimitsu Chemical Co., Ltd.) 40 wt% ・ Water 58 wt% Steam temperature 130 ° C. Steam time 15 minutes Comparative Example 1 PLLA: PDLA = 50: 50 PLLA: PDLA
= 100: 0, and a drawn yarn was obtained in the same manner as in Example 1. The strength of the obtained drawn yarn is 3.8 cN / d
tex and the boiling water shrinkage were 10.8%. Using this drawn yarn, a dyed fabric was obtained in the same manner as in Example 1.

As shown in Table 1, the C * value was 51.8 and the tear strength was 900 cN, which was excellent in chromatic coloring and durability, but had a problem in heat resistance at 200 ° C.

Comparative Example 2 PLLA: PDLA = 50: 50 and PLLA: PDLA
= 100: 0, except that the dyed fabric was obtained in the same manner as in Example 6.

As shown in Table 1, the C * value was 45.3 and the tear strength was 830 cN, which was excellent in chromatic color development and durability, but had a problem in heat resistance at 200 ° C.

[0068]

[Table 1]

[0069]

According to the present invention, chromatic color development is excellent,
A polylactic acid fiber structure having high heat resistance and a method for producing the same can be provided. Further, the obtained polylactic acid fiber structure is excellent in quality and texture, and thus is suitable for uses such as formal wear, women's clothing, and sportswear.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) D06P 3/54 D06P 3/54 Z F Term (Reference) 4H057 AA01 BA08 DA01 DA17 EA01 4J002 CF18W CF18X FD096 GC00 GK01 4L035 BB32 BB56 BB89 BB91 EE01 EE07 EE20 HH01 4L048 AA20 AA43 AA46 AA47 AA48 AA50 AB07 AC07 BA01 CA01 DA02 DA03

Claims (3)

[Claims] 1. A polylactic acid fiber comprising a blend of poly L-lactic acid and poly D-lactic acid is used at least in part,
A polylactic acid fiber structure having a chroma C * value of 20 or more. 2. The polylactic acid fiber structure according to claim 1, wherein the strength of the polylactic acid fiber is 2 cN / dtex or more. 3. A polylactic acid fiber characterized in that a polylactic acid fiber structure using at least a part of a polylactic acid fiber comprising a blend of poly L-lactic acid and poly D-lactic acid is dyed with a chromatic dye. The method of manufacturing the structure.