JP5815450B2 - Polyester latently crimped multifilament yarn and method for producing the same, dark-dyed fabric and method for producing the same - Google Patents

Description

  The present invention relates to a polyester latent-crimped multifilament yarn and a method for producing the same, and a deeply dyeable fabric and a method for producing the same.

  In the clothing field, especially in the clothing field such as formal black, where high dyeing properties are required, due to the recent high-end orientation, the unevenness due to the dyeing difference (that is, due to the difference in the dyeing speed between the two yarns when using a composite yarn) There has been a demand for a woven or knitted fabric (fabric) that has both excellent deep dyeability and stretch silky properties.

  Various studies have been made to obtain a fabric that meets these demands. For example, the highly dyed polyester unoriented yarn is subjected to a heat treatment at a temperature equal to or higher than the subsequent false twisting temperature without being subjected to a drawing treatment in advance, and then deep twisting is improved by performing false twisting simultaneously with drawing. There has been proposed a method for producing a polyester yarn (Patent Document 1).

  Further, the present inventors have proposed a number of methods for false twisting of a filament yarn using a fluid swirl nozzle for the purpose of obtaining a filament yarn with further improved deep dyeability. For example, a polyester latent crimpable composite filament yarn with a single filament fineness and a high crimp rate is arranged on the core yarn, and the sheath yarn has an uneven shape or fine pores on the surface, and the degree of orientation and shrinkage. A mixed entangled yarn obtained by arranging polyester crimped filament yarn having low properties and false twisting these core yarn and sheath yarn by a fluid swirling nozzle has been proposed (Patent Document 2). This mixed fiber entangled yarn has loops and sagging on the surface of the yarn, and a fabric including this mixed fiber entangled yarn as a constituent fiber can exhibit excellent deep dyeability.

JP-A-57-199825 Japanese Patent Laid-Open No. 11-158742

  However, the polyester yarn obtained by the method of Patent Document 1 has insufficient darkness to be a constituent fiber of a fabric used in the formal black field. In addition, since the crimpability is low, there is a problem that the stretchability is insufficient. Further, when the obtained filament yarn is dyed, there is a variation in color difference between the weights used in the dyeing process, which causes a problem of poor appearance and quality.

  Moreover, although the mixed fiber entanglement yarn of patent document 2 is excellent in stretch property and dark dyeing property, it originates in the thread | yarn distribute | arranged to a core part and a sheath part from the difference in a thread quality characteristic and a thread form. The difference in dyeing is expressed. Therefore, there is a problem that irritations occur in a fabric including this mixed fiber as a constituent fiber.

  The present invention solves such disadvantages of the prior art, and is suitable for obtaining a dry silky-touch fabric having both high dyeability and stretchability, stable quality and quality, and no irritation. It is a technical problem to provide a latently crimped multifilament yarn. In addition, by applying black dyeing to the fabric containing the polyester latently crimped multifilament yarn as a constituent fiber after the alkali weight reduction treatment, a dry silky-touch, dark-dyeing fabric that is stable in quality and quality and free from irritation is obtained. It is a technical problem to provide.

  As a result of intensive studies to solve the above problems, the present inventors have found that a polyester resin that is poorly soluble in an alkaline agent is disposed in the core portion, and a polyester resin that is readily soluble in the alkaline agent is disposed in the sheath portion, and the core. Polyester latent crimped multifilament yarn comprising a core-sheath composite fiber having a multi-leafed cross-section in the section, having a total fineness of 50 to 150 dtex, a single yarn fineness of 1.5 to 4 dtex, and a latent wrinkle The present inventors have found that a polyester latently crimped multifilament yarn characterized by a shrinkage ratio of 45% or more can solve the above-mentioned problems. That is, the present invention has the following contents.

(1) A core-sheath type composite fiber in which a polyester resin that is sparingly soluble in an alkaline agent is disposed in the core part, a polyester resin that is easily soluble in the alkaline agent is disposed in the sheath part, and the cross-section of the core part is a multileaf cross-sectional shape Polyester latent crimped multifilament yarn comprising: total polyester fineness of 50 to 150 dtex, single yarn fineness of 1.5 to 4 dtex, and latent crimp rate of 45% or more Crimped multifilament yarn.
(2) A fabric comprising the polyester latently crimped multifilament yarn of (1) as a constituent fiber.
(3) A dark-dyeing fabric obtained by subjecting the fabric of (2) to an alkali weight reduction treatment, wherein the polyester latent crimped multifilament yarns constituting the dark-dyeing fabric after the alkali weight reduction treatment are many. A deep-dyed fabric having a leaf cross-sectional shape and having an L ^* value of 12 or less after the black dyeing after the alkali weight reduction treatment.
(4) The core portion has a core-sheath structure in which a polyester resin that is hardly soluble in an alkali agent is disposed, a polyester resin that is easily soluble in an alkali agent is disposed in a sheath portion, and the cross-section of the core portion is a multileaf cross-sectional shape. Polyester highly oriented undrawn yarn having a single yarn fineness of 2 to 5 dtex and an elongation of 100% or more was used as a supply yarn, and heat treatment was performed at a temperature higher by 15 ° C. than the drawing false twisting temperature. Then, a method for producing a polyester latent crimped multifilament yarn, which is subjected to drawing false twisting under the following conditions (I) and (II), and these steps are continuously performed at a processing speed of 150 m / min or less. A process for producing a polyester latent-crimped multifilament yarn, characterized in that
(I) The number of false twists is 25000 / (0.9 × D) ^{1/2 to} 35000 / (0.9 × D) ^1/2 . In addition, D is the total fineness of the polyester latent crimped multifilament yarn after drawing false twisting.
(II) The drawing false twisting temperature is 140 to 200 ° C.
(5) The method for producing a polyester latent crimped multifilament yarn according to (4), wherein the supply yarn is cooled at room temperature after the heat treatment and before the drawing false twisting.
(6) A method for producing a deep-dyed fabric, wherein a fabric is obtained using the polyester latent crimped multifilament yarn obtained by the method (4) or (5) as a constituent fiber, and the fabric is A method for producing a deeply dyeable fabric having an L ^* value of 12 or less by performing an alkali weight loss treatment and then black dyeing.

  ADVANTAGE OF THE INVENTION According to this invention, the polyester latent crimp multifilament thread | yarn for obtaining the dry silky touch dark-dyeing fabric which has the stretch property, is stable in quality and quality, and has no irritation can be provided.

It is an example of sectional drawing of the core-sheath-type composite fiber which comprises the polyester latent crimped multifilament yarn of this invention. 1 is an example of a cross-sectional view of a polyester latent crimped multifilament yarn of the present invention having a multi-leaf cross-sectional shape by applying an alkali weight loss treatment. It is the schematic which shows one Embodiment of the apparatus which manufactures the polyester latent crimp multifilament yarn of this invention.

Hereinafter, the present invention will be described in detail.
The polyester latently crimped multifilament yarn of the present invention (hereinafter sometimes simply referred to as “multifilament yarn”) has a polyester resin that is sparingly soluble in an alkaline agent in the core portion and is easily soluble in the alkaline agent in the sheath portion. Polyester resin, and a core-sheath-type composite fiber having a multi-leaf cross-section in the core, and has a total fineness of 50 to 150 dtex and a single yarn fineness of 1.5 to 4 dtex. It is essential.

  As the core-sheath type composite fiber constituting the polyester latently crimped multifilament yarn of the present invention, as shown in FIG. 1, a polyester resin 2 that is hardly soluble in an alkali agent is arranged in the core part, and the sheath part is an alkaline agent. If it is the composite fiber by which the easily soluble polyester resin 1 was distribute | arranged, it will not specifically limit.

  The polyester resin that is easily soluble in the alkali agent used in the present invention is not particularly limited as long as it is a polyester resin that has higher solubility in the alkali agent than the polyester resin disposed in the core. For example, a resin obtained by copolymerizing a polyalkylene terephthalate copolymer as a main component and an aromatic dicarboxylic acid component having a sulfonate group and / or a polyalkylene glycol may be used. Among these, from the viewpoint of easy solubility by an alkali agent, a 5-sulfoisophthalic acid component (hereinafter sometimes abbreviated as “SIP”) is added in a proportion of 0.5 mol% to 5 mol%, and a polyethylene glycol component is added. A copolymerized polyester copolymerized at a ratio of 5% by mass to 15% by mass is preferable.

  The polyester resin that is hardly soluble in the alkali agent used in the present invention is not particularly limited as long as it is a polyester resin that is more hardly soluble in the alkali agent than the polyester resin disposed in the sheath. For example, a polyester resin in which 80 mol% or more of all structural units is ethylene terephthalate, butylene terephthalate, or propylene terephthalate can be used. Among these, polyethylene terephthalate (PET) in which 80 mol% or more of all structural units are ethylene terephthalate units is preferable from the viewpoint of cost and spinnability.

  The core-sheath type composite fiber constituting the polyester latent crimped multifilament yarn of the present invention is reduced in surface (sheath part) by applying an alkali weight reduction treatment as described later, and its cross section is shown in FIG. It becomes a multi-leaf cross-sectional shape as shown. That is, the core part needs to be formed so as to have a multilobal cross-sectional shape. The effect obtained by forming the core portion so as to have a multilobal cross-sectional shape will be described below.

  A fabric containing the multifilament yarn of the present invention as a constituent fiber is obtained, and the sheath portion is reduced by subjecting the fabric to a subsequent alkali weight reduction treatment, so that the core-sheath type composite fiber constituting the multifilament yarn has a multileaf cross section. It will have a shape. And when light is irradiated to the surface of this core-sheath-type composite fiber, light repeats irregular reflection by the irregular surface shape. Here, since the irregularly reflected light is absorbed inside the composite fiber, the reflected light to the outside is reduced, so that an effect of expressing a deep hue can be achieved. In addition, due to the special cross-sectional shape, a dry silky touch can be produced when the fabric is used.

  Furthermore, in the multifilament yarn of the present invention, it is necessary that the crimp rate (latent crimp rate) is 45% or more when crimp is developed during wet heat treatment performed under the conditions described later in the examples. Yes, it is preferably 45 to 70%, and more preferably 50 to 70%. By having a high crimpability (latent crimpability) of 45% or more, when a fabric having multifilament yarn is subjected to alkali weight loss treatment or black dyeing, voids are formed between the multifilament yarns, Appropriate bulge can be expressed. In addition, the complicated internal bending between the multifilament yarns reduces the amount of diffuse reflection light to the outside, increasing the color depth and further improving the deep dyeability. Further, when the latent crimp rate is less than 45%, the multifilament yarn is not sufficiently crimped. When such a multifilament yarn is used as a constituent fiber, the multifilament yarns have a structure point. Therefore, there is a problem that the stretchability is deteriorated.

  In the multifilament yarn of the present invention, if the above-described latent crimp rate is 45% or more, even if the fabric containing the multifilament yarn as a constituent fiber is subjected to alkali weight loss treatment or black dyeing treatment, Since the crimped state can be the same as in the case where the latent crimp of the multifilament yarn is developed, it is presumed that an excellent deep dyeing effect can be achieved in the fabric.

  The multi-leaf cross-sectional shape referred to in the present invention is preferably 15 leaves or more, more preferably 15 leaves to 35 leaves, more preferably 16 leaves to 25, from the viewpoint of deep dyeing developed by irregular reflection. Leaves are more preferred. Moreover, it is preferable that the width | variety (W) of the convex part in a multileaf cross-sectional shape is 0.3-1 micrometer minute thing. Moreover, it is preferable that the height of the convex part in multi-leaf cross-sectional shape is 1.5 to 3 times the width (W) of the said convex part. Furthermore, the arrangement distribution and the shape of the concavo-convex portions in the multi-leaf cross-sectional shape are not particularly limited, but usually, as shown in FIG. 2, the convex portions and the concave portions are distributed almost uniformly alternately, In general, the convex section has a rectangular or substantially trapezoidal cross section.

  In order to obtain the core-sheath type composite fiber constituting the polyester latent crimped multifilament yarn, a normal apparatus for obtaining the core-sheath type composite fiber can be used.

  The total fineness of the multifilament yarn of the present invention is required to be 50 to 150 dtex, and preferably 60 to 140 dtex. When the fabric is 150 dtex or less, the fabric weight can be prevented from becoming heavy, and a dry silky touch texture can be expressed. On the other hand, when it is 50 dtex or more, the fabric containing the multifilament yarn as a constituent fiber has an advantage that the texture is not too soft and the waist and elasticity can be exhibited.

  The single filament fineness of the multifilament yarn of the present invention needs to be 1.5 to 4 dtex, and preferably 2.0 to 3.8 dtex. By setting it as this range, the fabric which has a dry silky touch texture can be obtained. In other words, if the single yarn fineness is less than 1.5 dtex, the texture is too soft, and the fabric containing this multifilament yarn as a constituent fiber will have insufficient waist and firmness. On the other hand, if it exceeds 4 dtex, the fabric containing this multifilament yarn as a constituent fiber becomes hard and unsuitable for a formal material.

  That is, the core-sheath composite fiber constituting the multifilament yarn as described above has a multi-leafed cross-sectional shape after alkali weight reduction treatment, and has high crimpability after wet heat treatment such as scouring, dyeing and washing Due to the synergistic effect with the above, a dry silky touch is obtained when the fabric is used.

Next, the manufacturing method of the multifilament yarn of this invention is demonstrated.
First, as the supply yarn used in the manufacturing method of the present invention, a polyester resin that is hardly soluble in an alkali agent is arranged in the core portion, and a polyester resin that is easily soluble in the alkali agent is arranged in the sheath portion. Polyester highly oriented unstretched yarn (hereinafter simply referred to as “unstretched yarn”) having a core-sheath structure with a cross-sectional shape of a multilobal cross section, a single yarn fineness of 2 to 5 dtex, and an elongation of 100% or more. May be used). The cross-sectional shape of the polyester highly oriented undrawn yarn can be a multi-leaf cross-sectional shape by the alkali weight loss treatment after being formed into a fabric.

  The undrawn yarn needs to have a single yarn fineness of 2 to 5 dtex, and preferably 2.5 to 4.5 dtex. If the single yarn fineness is less than 2 dtex, the single filament fineness of the multifilament yarn obtained by drawing false twisting becomes too thin, so that when the fabric is made into a fabric, a uniform multileaf cross-sectional shape can be obtained after reducing the alkali. difficult. As a result, the obtained fabric tends to be light-colored, and the fabric cannot exhibit a good deep dyeing property and is inferior to a silky touch. On the other hand, when the single yarn fineness exceeds 5 dtex, even if the drawing false twisting process is performed so as to achieve high crimping, an appropriate swelling feeling is insufficient and the texture becomes hard.

  The elongation of the undrawn yarn used in the production method of the present invention needs to be 100% or more, preferably 120% or more, and more preferably in the range of 125% to 150%. When the elongation of the undrawn yarn is less than 100%, the dark dyeing effect of the resulting fabric is reduced, and the silky touch is inferior. From the viewpoint of easy handling of undrawn yarn, the upper limit of elongation is preferably about 200%.

  In the production method of the present invention, the above-mentioned supply yarn is subjected to heat treatment at a temperature higher by 15 ° C. or more than the drawing false twisting temperature, and then subjected to drawing false twisting under the following conditions (I) and (II). It is essential to carry out these steps continuously at a processing speed of 150 m / min or less.

(I) The number of false twists is 25000 / (0.9 × D) ^{1/2 to} 35000 / (0.9 × D) ^1/2 . In addition, D is the total fineness (dtex) of the polyester latent crimped multifilament yarn after drawing false twisting.
(II) The drawing false twisting temperature is 140 to 200 ° C.

  In the production method of the present invention, if the processing speed exceeds 150 m / min, it becomes difficult to set multi-filament yarns having high crimpability as the processing conditions become difficult to set. Furthermore, 80 to 140 m / min is a preferable range from the viewpoint of the balance between the processing cost and the number of false twists.

The heat treatment will be described below.
In the heat treatment applied before the drawing false twisting process, the heat treatment temperature needs to be higher than the drawing false twisting temperature by 15 ° C. or higher, preferably 20 ° C. or higher. A high temperature of 30 ° C. or higher is more preferable, and 45 ° C. or higher is even more preferable. With such a heat treatment temperature, the thermal efficiency becomes high, and the resulting multifilament yarn can exhibit excellent crimping properties, and can also exhibit a preferable texture and darkness.

  The heater used for the heat treatment should use a non-contact heater from the viewpoint of stably imparting thermal efficiency to the undrawn yarn, and from the viewpoint of improving quality by suppressing yarn breakage and fuzz during false twisting. Is desirable.

  The length of the heater used for the heat treatment is preferably 0.5 to 1.5 m, more preferably 0.6 to 1.2 m, from the viewpoint of providing sufficient heat.

  After the heat treatment, the supply yarn is preferably cooled at room temperature before the drawing false twisting process. By performing the cooling, there is an advantage that the internal structure of the yarn after the heat treatment is further stabilized, and dyeing spots in the longitudinal direction of the yarn are reduced.

  In the present invention, the heat treatment temperature applied before the drawing false twisting is heat-treated at a temperature higher by 15 ° C. or more than the drawing false twisting temperature, preferably by cooling to room temperature and then carrying out the drawing false twisting. A deep dyeing property can be expressed in the filament yarn. The reason is not clear, but the heat treatment improves the crystallinity of the multifilament yarn, but does not improve the degree of orientation, and further lowers the drawing false twisting tension, so that deep dyeing can be achieved. It is estimated to be.

The stretch false twisting will be described below.
The drawing false twisting is performed under the above processing conditions (I) and (II). The above-mentioned unstretched yarn is stretched under specific false twisting conditions and is subjected to false twisting, so that when it is made into a fabric, it is possible to develop a stretch performance resulting from high crimpability. Filament yarn can be obtained.

The number of false twists (T / M) when the total fineness of the polyester latent crimped multifilament yarn after drawing false twisting is D (dtex) is 25000 / (0.9 × D) ^{1/2 to} 35000. /(0.9×D) ^1/2 and preferably 28000 / (0.9 × D) ^{1/2 to} 33000 / (0.9 × D) ^1/2 . If the number of false twists (T / M) is less than 25000 / (0.9 × D) ^1/2 , high crimpability cannot be obtained, and sufficient stretchability cannot be imparted to the multifilament yarn. It is inferior to the silky touch. On the other hand, if it exceeds 35000 / (0.9 × D) ^1/2 , multifilament yarns are frequently broken, and problems in processing operations appear. Moreover, it will also be inferior to deep dyeing property.

  The drawing false twisting temperature needs to be 140 to 200 ° C, and preferably 150 to 180 ° C. When the drawing false twisting temperature is less than 140 ° C., the thermal efficiency with respect to the supplied yarn is deteriorated, and high crimpability cannot be imparted. On the other hand, when the drawing false twisting temperature exceeds 200 ° C., the supply yarns are easily fused to each other, the sharp feeling is emphasized, and the silky feeling is reduced. Moreover, there is a problem that high crimpability cannot be imparted. In addition, in this invention, extending | stretching false twist processing temperature means heater temperature.

  The draw ratio in draw false twisting is preferably 1.3 to 1.7 times, and more preferably 1.4 to 1.6 times. If it is less than 1.3 times, there is a problem that the working tension at the time of drawing false twisting is lowered, yarn breakage is likely to occur, and processing operability is lowered. On the other hand, if it exceeds 1.5 times, there is a problem that yarn breakage is likely to occur during the processing.

  In addition, it does not specifically limit as a drawing false twist apparatus used for this invention, A well-known thing can be used suitably. Among them, a material that can exhibit high crimpability and can secure a cooling zone at room temperature for stabilizing the internal structure of the yarn after the heat treatment as a yarn path for the processing step is preferable.

Next, the manufacturing method of the multifilament yarn of this invention is demonstrated based on FIG.
FIG. 3 is a process schematic diagram showing one embodiment of the production method of the present invention. The polyester highly oriented unstretched yarn 3 that is a supply yarn is subjected to a heat treatment by a heat treatment heater 5 installed between the supply roller 4 and the first take-up roller 6. And between the 1st taking-up roller 6 and the 2nd taking-up roller 7, it cools at room temperature preferably. Continuously continuously crimped between the second take-up roller 7 and the third take-up roller 10 using the false twist heater 8 and the pin type false twist device 9 under the above-mentioned specific draw false twist conditions. Processing is done. In this way, the polyester latently crimped multifilament yarn of the present invention is obtained. Next, the obtained multifilament yarn passes through the third take-up roller 10 and is wound around the package 12 by the take-up roller 11. Note that there is no problem even if heat treatment and room temperature cooling are simultaneously performed between the supply roller 4 and the second take-up roller 7 without using the first take-up roller 6. In addition, it is preferable to set the processing tension of the room temperature cooling zone at this time in the range of 2 to 4 g. By setting to such a range, the processing tension in the false twist zone can be stabilized and the quality can be improved.

  Various fabrics can be obtained by using the multifilament yarn of the present invention as a constituent fiber. The form of such a fabric is not particularly limited, and fabrics such as a plain structure, a twill structure, a satin structure, or a changed structure by dobby or jacquard; knitted fabrics such as weft knitting, tricot knitting, and Raschel knitting Can be mentioned.

  The content ratio of the multifilament yarn in such a fabric is preferably 50% by mass or more with respect to the entire fabric obtained from the viewpoint of expressing the effects of the present invention of deep dyeability and stretch silkiness, and 75 The content is more preferably at least mass%, particularly preferably 100 mass%.

And as mentioned above, after producing a fabric using the multifilament yarn of the present invention, when the fabric is subjected to alkali weight loss treatment or wet heat treatment under specific conditions, the multifilament contained in the fabric The core-sheath composite fiber constituting the yarn has a multi-leafed cross-sectional shape and further has a specific crimp rate. As a result, it is possible to obtain a deeply dyeable fabric having an L ^* value of 12 or less when black dyeing is performed at 135 ° C. for 30 minutes. In addition, the alkali agent used for an alkali weight reduction process and process conditions (temperature, time, bath ratio, etc.) are not specifically limited, A normal condition can be applied. Further, the conditions for black dyeing are not particularly limited as long as black dyeing can be satisfactorily performed.

  The deeply dyeable fabric of the present invention may be subjected to various processes such as dark dyeing, softness, antistatic, water repellency as well as black dyeing. Further, for the purpose of improving the texture, a supplementary twist of about 500 to 2000 T / M may be applied to the multifilament yarn as the constituent fiber.

  EXAMPLES Next, the present invention will be described more specifically with reference to examples, but the present invention is not limited thereto.

The evaluation method used in the present invention is shown below.
(1) Fineness Measured according to the method of JIS L1013 8.3.1.

(2) Potential crimp rate (stretchability)
The resulting multifilament yarn was left for a whole day and night in a state where it was hung on a stand using a measuring instrument having a frame circumference of 1.125 m, taking a casket of 5 turns. Next, the wet heat treatment for 30 minutes was performed in boiling water with a load of 0.000147 cN / dtex (load 1) applied. Thereafter, the water was lightly removed with a filter paper and left to air dry for 30 minutes. Next, with the load 1 applied, a light load (load 2) of 0.00177 cN / dtex was further applied, and the length A of the cassette was measured. Next, only load 2 was removed, and a heavy load of 0.044 cN / dtex was applied to measure the length B of the cassette. The latent crimp rate was calculated using the following formula.
(Latent crimp rate) (%) = [(B−A) / B] × 100

(3) Elongation It measured according to the method of JIS L1013 8.5.5.

(4) L ^* value For fabrics obtained from the multifilament yarns obtained in the examples and comparative examples, a scouring agent (manufactured by Nikka Chemical Co., Ltd., “Sunmall FL”) was added to water at a concentration of 2 g / L Using the dissolved aqueous solution, scouring was performed at 80 ° C. for 20 minutes. Thereafter, alkali reduction treatment was performed at 98 ° C. for 30 minutes using caustic soda (10 g / L). Subsequently, disperse dyes (Dystar Co., “Dianics Black HG-FS” (200%), 7.5% omf), dyeing assistant (Nikka Chemical Co., Ltd., “Nikka Sun Salt SN-130”), Staining was performed at 135 ° C. for 30 minutes using 5 cc / L) and acetic acid (0.2 cc / L). The bath ratio at that time was 1:50.

Then, it wash | cleaned at 80 degreeC for 20 minute (s) using the reducing cleaning agent (manufactured by Yushi Co., Ltd., "Binol P-55") (5 g / L). And the reflectance was measured with respect to the cloth after washing using a spectrophotometer (manufactured by Macbeth, “MS-CE3100 type”), and the L ^* value was determined from the color difference formula of CIE Lab. The L ^* value becomes deeper as the value is smaller.

(5) Inter-weight dyeing quality (cylinder dyeing evaluation)
A cylindrical knitted fabric was prepared for each of the obtained multifilaments for each weight, and the dyeing quality between the weights was visually observed and evaluated according to the following criteria.
A: Good with little variation in dyeing quality.
(Triangle | delta): There existed dispersion | variation in dyeing | staining quality and was a little bad.
X: There was variation in the dyeing quality, which was bad.

(6) Deep dyeing (sensory evaluation)
The surface of the obtained fabric was visually observed and evaluated according to the following criteria.
○: The target deep dyeability (deep hue) was satisfied and it was good.
(Triangle | delta): It did not fully satisfy the target deep dyeing property, but was a little bad.
X: It was bad without satisfying the target deep dyeability.

(7) Texture (silky)
The touch of the obtained fabric was confirmed and evaluated according to the following criteria.
○: The target silky property was satisfied, and the texture was good.
Δ: The target silky property was not fully satisfied, and the texture was slightly bad.
X: The target silky property was not satisfied, and the texture was bad.

Example 1
As the supply yarn, highly oriented polyester unstretched yarn [core resin: polyethylene terephthalate (relative viscosity: 1.385)] [sheath resin: SIP, which can be formed into a trefoil cross-sectional shape as shown in FIG. Is a copolymerized polyethylene terephthalate having a melt viscosity of 1550 dpa · s (290 ° C.) obtained by copolymerization of 8.0% by mass of polyethylene glycol having an average molecular weight of 8000, and having an elongation of 132% and 90 dtex. The polyester latent crimped multifilament yarn (60.8 dtex / 24 filament) of the present invention was obtained under the conditions shown in Table 1 according to the process shown in FIG.

  The obtained multifilament yarn was subjected to additional twisting of S-1500 T / M and Z-1500 T / M. The multifilament yarn was used as a warp and a weft in a 2: 2 arrangement to weave a flat double woven fabric (warp density: 190 / 2.54 cm, weft density: 140 / 2.54 cm). The obtained woven fabric was subjected to scouring, alkali reduction treatment, black dyeing and washing treatment by the method (4) described above. Table 1 shows the evaluation of the obtained multifilament yarn and fabric.

(Example 2)
A multifilament yarn was obtained under the same processing method and stretch false twisting conditions as in Example 1 except that a cooling zone at room temperature was not provided for the heat-treated yarn, and further a woven fabric was obtained. Table 1 shows the evaluation of the obtained multifilament yarn and fabric.

(Comparative Example 1)
A multifilament yarn was obtained under the same processing method and stretched false twist conditions as in Example 1 except that the false twisting temperature was increased to 210 ° C., and further a woven fabric was obtained. Table 1 shows the evaluation of the obtained multifilament yarn and fabric.

(Comparative Example 2)
A multifilament yarn was obtained under the same processing method and stretch false twisting conditions as in Example 1 except that the heat treatment temperature was 160 ° C., and further a woven fabric was obtained. Table 1 shows the evaluation of the obtained multifilament yarn and fabric.

(Comparative Example 3)
As shown in Table 1, a multifilament yarn was obtained by the same processing method and stretch false twisting conditions as in Example 1 except that the number of filaments in the supply yarn was increased and the single yarn fineness was reduced, and further a woven fabric was obtained. Table 1 shows the evaluation of the obtained multifilament yarn and fabric.

(Comparative Example 4)
A multifilament yarn was obtained under the same conditions as in Example 1 except that the number of false twists was Z-3250 T / M, and a woven fabric was further obtained. Table 1 shows the evaluation of the obtained multifilament yarn and fabric.

(Comparative Example 5)
A multifilament yarn was obtained under the same processing method and stretched false twist conditions as in Example 1 except that the number of false twists was Z-4870 T / M, and further a woven fabric was obtained. Table 1 shows the evaluation of the obtained multifilament yarn and fabric.

(Comparative Example 6)
A multifilament yarn was obtained under the same processing method and drawn false twist conditions as in Example 1 except that the elongation of the supplied yarn was 92%, and further a woven fabric was obtained. Table 1 shows the evaluation of the obtained multifilament yarn and fabric.

  The fabric with the multifilament yarn obtained in Example 1 as a constituent fiber and subjected to alkali weight loss and wet heat treatment is particularly excellent in darkness and stretchability, and additionally has a dry silky touch texture. there were.

  The fabric having the multifilament yarn obtained in Example 2 as a constituent fiber and subjected to alkali weight loss and wet heat treatment is excellent in deep dyeability and stretchability, and additionally has a dry silky touch texture. It was. However, there is a slight variation between the weights due to the color difference, and problems such as difficulty in stable supply of the processed yarn due to a decrease in the M yield are inherent.

  Since the multifilament yarn obtained in Comparative Example 1 was obtained at a drawing false twisting temperature as high as 210 ° C., the multifilament yarn had poor stretchability. The fabric containing the multifilament yarn as a constituent fiber is inferior in dry silky touch and lacks in deep dyeing characteristics.

The multifilament yarn obtained in Comparative Example 2 was obtained under the condition that the difference between the heat treatment heater temperature and the false twist heater temperature was less than 15 ° C. Therefore, a fabric containing the multifilament yarn as a constituent fiber has low crimpability, tends to have a high L ^* value, and is poor in dyeing quality, texture, and darkness.

  The multifilament yarn obtained in Comparative Example 3 had a single yarn fineness that was less than the range defined in the present invention. For this reason, the fabric including the multifilament yarn as a constituent fiber cannot obtain a dry silky touch texture although a soft texture can be obtained.

  The multifilament yarn obtained in Comparative Example 4 had a false twist number that was less than the range defined in the present invention. For this reason, a fabric containing the multifilament yarn as a constituent fiber has low crimpability and a dry silky touch texture cannot be obtained.

  In the multifilament yarn obtained in Comparative Example 5, the number of false twists was larger than the range specified in the present invention. For this reason, the fabric containing the multifilament yarn as a constituent fiber lacks the deep dyeability, and many yarn breaks occur when the multifilament yarn is produced, which causes a problem in processing operation.

  In the multifilament yarn obtained in Comparative Example 6, the elongation of the supplied yarn was less than the range defined in the present invention. Therefore, the fabric containing the multifilament yarn as a constituent fiber has poor dyeing quality, dry silky touch, and dark dyeing property.

DESCRIPTION OF SYMBOLS 1 Polyester resin easily soluble in alkali agent 2 Polyester resin hardly soluble in alkali agent 3 Polyester highly oriented undrawn yarn 4 Supply roller 5 Heat treatment heater 6 First take-up roller 7 Second take-up roller 8 False twist heater 9 Pin type False twisting device 10 Third take-up roller 11 Take-up roller 12 Package

Claims (6)

  Polyester comprising a core-sheath type composite fiber in which a polyester resin that is hardly soluble in an alkali agent is arranged in the core part, a polyester resin that is easily soluble in an alkali agent is arranged in the sheath part, and the cross section of the core part is a multileaf cross-sectional shape Polyester latent crimped multifilament yarn characterized by having a total fineness of 50 to 150 dtex, a single yarn fineness of 1.5 to 4 dtex, and a latent crimp rate of 45% or more. Filament yarn.   A fabric comprising the polyester latently crimped multifilament yarn of claim 1 as a constituent fiber. A deep-dyed fabric obtained by subjecting the fabric of claim 2 to an alkali weight reduction treatment, wherein the polyester latent crimped multifilament yarn constituting the dark-dyed fabric after the alkali weight reduction treatment has a multileaf cross-sectional shape. A dark-dyeing fabric characterized by having an L ^* value of 12 or less after black dyeing after the alkali weight reduction treatment. A polyester resin that is hardly soluble in an alkaline agent is arranged in the core part, a polyester resin that is easily soluble in the alkaline agent is arranged in the sheath part, and the core part has a core-sheath structure in which the cross section is a multi-leaf cross-sectional shape, And after using a polyester highly oriented undrawn yarn having a single yarn fineness of 2 to 5 dtex and an elongation of 100% or more as a supply yarn, after heat treatment at a temperature higher by 15 ° C. than the drawing false twisting temperature, A method for producing a polyester latent crimped multifilament yarn, which is subjected to drawing false twisting under the conditions (I) and (II), and these steps are continuously carried out at a processing speed of 150 m / min or less. A method for producing a polyester latently crimped multifilament yarn characterized by the above.
(I) The number of false twists is 25000 / (0.9 × D) ^{1/2 to} 35000 / (0.9 × D) ^1/2 . In addition, D is the total fineness of the polyester latent crimped multifilament yarn after drawing false twisting.
(II) The drawing false twisting temperature is 140 to 200 ° C.   The method for producing a polyester latent-crimped multifilament yarn according to claim 4, wherein the supply yarn is cooled at room temperature after the heat treatment and before the drawing false twisting. A method for producing a deep-dyed fabric, wherein a fabric is obtained using the polyester latent crimped multifilament yarn obtained by the method of claim 4 or 5 as constituent fibers, and the fabric is subjected to alkali weight loss treatment. And then black dyeing to obtain a deeply dyeable fabric having an L ^* value of 12 or less.

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