JP3452154B2 - Method for producing polyester composite yarn and polyester woven / knitted fabric - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyester composite yarn, and more specifically, by containing a heat-extensible polyester multifilament and a polyester multifilament having a high dissolution rate in an alkaline hot aqueous solution, a soft feeling, a swelling feeling, The present invention relates to a polyester composite yarn capable of providing a woven or knitted fabric having an excellent feeling of tightness.

[0002]

2. Description of the Related Art Polyester multifilaments are widely used in the fields of clothing, daily life materials, industrial materials, etc. by taking advantage of their excellent characteristics. BACKGROUND ART Mainly in the field of clothing, different shrinkage mixed fiber yarns having different heat shrinkage rates among constituent filaments are well known. When the different shrinkage mixed yarn is heat-treated, a difference in heat shrinkage property becomes apparent, a difference in yarn length is developed, and bulkiness is obtained. However, under the constraint of the structure of the woven or knitted fabric, the development of the yarn length difference due to the heat treatment may be suppressed, and sufficient bulkiness may not be obtained. As one of means for solving the problem of the different shrinkage mixed yarn, there is a different shrinkage mixed yarn containing a yarn having a high dissolution rate in an alkaline hot aqueous solution. Japanese Unexamined Patent Publication No. 6-16826 is obtained by mixing differently shrinking mixed fiber (A) and easily soluble yarn (B), and the easily water soluble yarn (B) has different shrinkage in boiling water. It is larger than the mixed fiber (A). The different-shrinkage mixed filament yarn exhibits the different-shrinkage effect in the different-shrinkage mixed yarn (A) and the different-shrinkage effect between the easily soluble yarn (B) and the different-shrinkage mixed yarn (A) by heat treatment. After that, the easily-dissolved yarn (B) is eluted by an alkali treatment to obtain softness and a feeling of swelling.

However, the different shrinkage mixed filament yarn has the following problems. The different shrinkage mixed yarn (A) and the easily soluble yarn (B) are mixed, and there are filaments having at least three kinds of heat shrinkage ratios, but since all of the constituent filaments are heat shrunk, a woven or knitted fabric The difference in yarn length developed under the restraining force of No. 2 is not different from that of the conventional hetero-shrink mixed yarn. In the dyeing process, if relaxing and presetting is followed by alkaline hot water treatment to elute the easy-to-dissolve unwound (B), which has the highest heat shrinkage, the different shrinkage in the remaining different shrinkage mixed fiber (A) The effect is not so different from that of the conventional hetero-shrink mixed yarn, and does not necessarily satisfy the swelling feeling.

[0004]

DISCLOSURE OF THE INVENTION The present invention is intended to solve the above problems and comprises a polyester multifilament having a heat-extending property and a multifilament having a high dissolution rate in an alkaline hot aqueous solution. By using this polyester composite yarn, even when the texture of the woven or knitted fabric is restrained, a sufficient yarn length difference can be exhibited during dyeing processing, and a soft feeling and swelling feeling that are unique to conventional heterogeneous shrinkage mixed yarns can be woven. It is intended to be given to a knitted fabric.

[0005]

That is, the present invention provides a polyester multifilament A to which the following heat shrinkage characteristics are satisfied.
A composite yarn containing at least C and having an entanglement degree of 20 to 100 co / m, wherein the polyester multifilament B has a dissolution rate of 5 times or more with respect to A and C in an alkaline hot aqueous solution. Composite yarn. SHD (A) ≦ 0 [%] ………………………… (1) SHD (B)> 0 [%] …………………… (2) SHD (C)> 0 [%] ………………………… (3) (However, SHD (A), SHD (B), SHD (C) are the dry heat shrinkage rate of polyester multifilament A, B, C at 160 ℃. Is shown).

The polyester composite yarn of the present invention is required to be constituted by including three or more kinds of polyester multifilaments. The three types of polyester multifilaments are as follows. (1) Polyester multifilament A having a dry heat 160 ° C. shrinkage of 0% or less. (2) Polyester multifilament B having a dry heat shrinkage of 160 ° C. of more than 0% and a dissolution rate of 5 times or more in an aqueous alkali hot solution than polyester multifilaments A and C. (3) Polyester multifilament C having a dry heat shrinkage of 160 ° C. of more than 0%.

The polyester used in the present invention is a polymer having an ester bond and having a fiber-forming ability, but the polyester multifilaments A and C and the polyester multifilament B are clearly different in the composition of the polymer. There is. This is because the difference in the dissolution rate with respect to the alkaline heat (100 ° C.) aqueous solution is made to differ by 5 times or more. Therefore, polyester multifilaments A and C
Is not preferable because it has an extremely high dissolution rate in an alkali hot aqueous solution, and specifically, polyethylene terephthalate is preferable. However, in the range where the dissolution rate difference with the polyester multifilament B is satisfied, the third
The components may be copolymerized. Further, a small amount of a matting agent such as titanium oxide, a fine pore forming agent such as kaolinite, an antistatic agent and the like may be added. It is preferable that the polyester multifilament B has a relatively high dissolution rate in an alkali hot aqueous solution. Specifically, polyethylene glycol and dimethyl 5-sodium isophthalate,
Polyester to which isophthalic acid or the like is added or copolymerized is preferable. The polyester composite yarn of the present invention is knitted and woven and then subjected to an alkali treatment at the time of dyeing to elute and remove the polyester multifilament B. If the dissolution rate of the polyester multifilament B in the alkali hot aqueous solution is less than 5 times the dissolution rate of the polyester multifilaments A and C, the weight loss of the polyester multifilaments A and C will proceed too much, resulting in a dull texture, which is not preferable. It is more preferably 10 times or more.

The polyester multifilament A needs to have an SHD (dry heat 160 ° C. shrinkage) of 0% or less by a measuring method described later. This is because in the heat treatment in the dyeing process, a sufficient yarn length difference is exhibited even under the constraint of the texture of the woven or knitted fabric. When the SHD of the polyester multifilament A is more than 0%, all the constituent filaments of the composite yarn will be heat-shrinked, and a sufficient yarn length difference will not be exhibited as in the case of the conventional different shrinkage mixed yarn. , Softness and swelling are insufficient. More preferably −
It is 15% to -2%. The polyester multifilaments B and C need to have an SHD greater than 0%. It is more preferably 5% to 75%. Due to the coexistence of the heat-shrinkable multifilament and the heat-extensible multifilament, a sufficient yarn length difference can be obtained by the heat treatment in the dyeing process. The magnitude relationship of the SHD between the polyester multifilament B and the polyester multifilament C is not particularly limited, but it is preferable that the SHD is equal or the polyester multifilament C is larger. This is because the polyester multifilament B has an SHD that is the largest because it is treated with an alkali to be eluted and removed, which leads to a lack of firmness and tends to give a rough texture.

The monofilament denier of the filaments constituting the polyester multifilament A is preferably relatively small in order to obtain a soft touch, and is preferably 0.1 to 3.0.
An example is denier. The monofilament denier of the filaments constituting the polyester multifilament C is preferably relatively large in order to obtain a feeling of tension and elasticity, and is preferably 2.0 to
An example is 10.0 denier. The monofilament denier of the filaments constituting the polyester multifilament B is preferably 1.0 denier or more. The polyester multifilament B is eluted and removed with an alkaline hot aqueous solution, and the voids generated thereafter give the woven or knitted fabric a feeling of swelling. This is because the effect of improvement becomes thin. However, if the single fiber denier is too large, it becomes difficult to elute and remove, and the weight reduction rate of the polyester multifilaments A and C becomes too large. Therefore, it is preferable to set it to about 5.0 denier or less.

The cross-sectional shape of the filaments constituting the polyester multifilaments A and C is not particularly limited, and in addition to a normal round cross-section, any of a multi-lobed cross section, a polygon cross section, a hollow cross section, and other special irregular cross sections are applicable. It is possible. Although any cross section of the filaments constituting the polyester multifilament B can be applied, a hollow cross section is particularly preferable. The filaments that compose the polyester multifilament B, which is subjected to alkaline hot water treatment for elution and removal, require a certain cross-sectional area to provide voids that lead to a bulging feeling after elution and removal. However, large single fiber denier makes elution difficult. In addition to this, the weight loss rate of the polyester multifilaments A and C is increased to bring about a fluffy texture. If the outer peripheral portion has a large cross-sectional area but is composed of a filament having a hollow portion, the filament can be easily eluted and removed, and sufficient voids can be provided while suppressing the weight reduction rate of the polyester multifilaments A and C. or,
When obtaining voids of the same size, the hollow cross-section yarn can consume less soluble polymer than the solid cross-section yarn. Furthermore, the cross-sectional shape of the filaments forming the polyester multifilament B is preferably a hollow cross section having a plurality of hollow portions. This is related to the fact that the composite yarn of the present invention is often knitted and woven in a twisted state. When a multifilament composed of a hollow cross-section filament having a single hollow part is twisted, the hollow part may be crushed and the cross section of the constituent filament may be flattened to reduce the outer peripheral cross-sectional area. When the outer peripheral cross-sectional area is reduced, the voids after elution and removal are reduced, which is not preferable. Therefore, by making the cross-sectional shape of the constituent filament a hollow cross section having a plurality of hollow portions, it becomes difficult for the hollow portions to be crushed even when twisted, and the outer peripheral cross-sectional area is easily maintained. In particular, a multifilament composed of hollow cross-section filaments having four hollow portions is preferable.

The polyester composite yarn of the present invention comprises at least three kinds of polyester multifilaments A, B and C, but the polyester multifilament B to be eluted and removed with an alkaline hot aqueous solution is
It is preferable to contain 2 to 30% by weight. 2% by weight
When it is less than the above, the voids after elution become small, and the effect of improving the bulging feeling becomes small. If it exceeds 30% by weight,
Elution becomes difficult and polyester multifilament A
The weight loss rate of C and C becomes large, and the feeling of tightness is insufficient, which is not preferable. Both of the polyester multifilaments A and C are preferably contained in the composite yarn in an amount of 10% by weight or more. 1 polyester multifilament A
If it is less than 0% by weight, the soft feeling of the surface becomes thin, which is not preferable. 10 polyester multifilament C
If it is less than 10% by weight, the feeling of tightness is insufficient, which is not preferable.

The polyester composite yarn of the present invention needs to be subjected to a fluid entanglement treatment. Further, it is necessary that Di (degree of entanglement) by the measuring method described later is 20 or more and 100 or less. This is to satisfy the post-process passability of the composite yarn. When Di is less than 20 / m, the yarn breakage increases in the post-process such as twisted yarn and knitting and weaving, and the passability is deteriorated, which is not preferable. When it exceeds 100 pcs / m, the texture becomes coarse and hard, which is not preferable. It is more preferably 30 / m or more and 80 / m or less.

It is particularly preferable that the constituent filaments of the polyester multifilament B and C constituting the polyester composite yarn of the present invention are mixed and interlaced. This is related to the elution of the polyester multifilament B by the alkaline hot water treatment. In the case where the composite yarn in the woven or knitted fabric is relaxed in the dyeing process, heat-treated with a preset, a yarn length difference is developed, and then the polyester multifilament B is eluted by alkaline hot water treatment, the polyester multifilaments B and C When the constituent filaments are mixed and intermixed with each other, voids can be evenly provided between the constituent filaments of the polyester multifilament C mainly constituting the core after the yarn length difference is expressed, and the effect of improving the bulging feeling can be obtained. Easy and preferable. If the polyester multifilaments B and C are not mixed and intermixed with each other, after the polyester multifilaments B are eluted and removed, it is difficult to form voids between the constituent filaments of the polyester multifilaments C, and the effect of improving the swelling feeling becomes small. In this way, polyester multifilaments B and C
In order to create a state in which the respective constituent filaments are mixed and mixed with each other, polyester multifilaments B and C are used.
Is preferably subjected to fluid entanglement treatment, ply twisting, composite false twisting, etc., and then again subjected to composite fluid entanglement treatment with the polyester multifilament A.

The polyester multifilament A constituting the polyester composite yarn of the present invention is located at the outermost peripheral portion of the composite yarn by the heat treatment in the dyeing process.
It is more preferable that the composite yarn is located at the outer peripheral portion relative to other constituent multifilaments at the time when the composite yarn is formed. As a result, the soft feeling and the bulging feeling can be further improved by the synergistic effect of the difference in shrinkage between the polyester multifilament A and the other constituent multifilaments. In order to position the polyester multifilament A in the outer peripheral portion in the composite yarn as described above, it is rational to excessively supply the polyester multifilament A to other constituent multifilaments during the complex fluid entanglement treatment.

Next, an example of the method for producing the polyester composite yarn of the present invention will be described. The polyester multifilament A constituting the polyester composite yarn of the present invention is SHD (dry heat 1
It is necessary that the shrinkage ratio (60 ° C.) is 0% or less. For that purpose, polyester is melted and discharged at a speed of 2000-
A highly oriented undrawn yarn drawn at 4000 m / min can be preferably used. The SHD becomes 0% or less by subjecting the highly oriented undrawn yarn to a relaxation heat treatment using a non-contact heater at a relaxation rate as high as 20% or more. It should be noted that the diameter may be a step in which the highly oriented undrawn yarn is drawn while being heated to a temperature near the glass transition temperature before the relaxation heat treatment and is taken without heat setting.

Polyester multifilament C is SH
It is necessary that D be greater than 0%. More preferably, it is 5 to 75%. Such yarns should be stretched while heating unstretched or highly oriented unstretched yarn obtained by melt-spinning polyester to a temperature near the glass transition temperature, and do not heat-set or slightly heat-set. Regulates SHD.

The polyester multifilament B is required to have a dissolution rate 5 times or more higher than that of the polyester multifilaments A and C by the alkaline hot water treatment. Therefore, the polymer composition of the polyester multifilament B needs to have higher alkali hydrolyzability than the polymer composition of the polyester multifilaments A and C. In such a polymer composition, 5 to 20 mol% of all acid components are copolymerized with an isophthalic acid component,
Further, those containing 3 to 5 wt% of polyalkylene glycol (preferably having a molecular weight of 10,000 or more) with respect to the polyester are preferable. The SHD of the polyester multifilament B is required to be higher than 0%, but like the polyester multifilament C, the SHD can be adjusted by melt spinning, drawing, and optionally heat setting.

Three or more kinds of polyester multifilaments including these polyester multifilaments A, B, C are subjected to a fluid entanglement treatment to form a composite, in which case a so-called interlacer nozzle, Taslan nozzle, etc. are preferably used. it can. The Di (degree of entanglement) of the composite yarn must be 20 or more and 100 or less. It is preferable that the polyester multifilaments B and C have their constituent multifilaments mixed and intermixed as uniformly as possible.
To this end, polyester multifilaments B and C
It is more preferable to perform fluid entanglement treatment, ply twisting, and composite false twisting in advance in the meantime. Also, all constituent polyester multifilaments may be aligned and subjected to fluid entanglement treatment,
It is more preferable that the polyester multifilament A is excessively supplied to the other constituent polyester multifilaments to entangle the composite fluid.

The polyester composite yarn of the present invention is twisted as necessary, wet-heat set and / or sizing, and knitted or woven. The heat history before knitting and weaving is preferably small,
The temperature is preferably below the glass transition temperature.
Dyeing is performed after weaving and knitting, but relaxation and presetting are performed to reveal the difference in heat shrinkage between the constituent filaments in the composite yarn and to express the difference in yarn length. After the yarn length difference is imparted, an alkali hot water treatment is performed to elute and remove the polyester multifilament B relatively located in the core portion or the middle layer portion in the composite yarn. By eluting and removing the polyester multifilament B, a void is formed between the constituent filaments of the other multifilament (polyester multifilament C) relatively located in the core portion in the composite yarn, and the bulging feeling is improved. After that, dyeing and final setting are performed in the same manner as in a normal polyester multifilament woven or knitted fabric to obtain a dyed fabric.

Next, the measuring method used in the present invention will be described. [SHD] (dry heat 160 ° C shrinkage [%]) Initial load 1/10 [g / de] with a lap reel with an appropriate frame circumference
n], take a roll of 8 turns and put 1/30 [g / de]
n] is applied and the length L0 [cm] is measured. Then, remove the load, 1/1000 [g / den]
Immerse the maze in boiling water for 30 minutes with the load applied. Then, remove the load from the boiling water, remove the load, cool, and apply a load of 1/30 [g / den] again,
Measure the length L1 [cm] of the skein at that time. Then remove the load and dry for 30 minutes at 60 ° C, then 1/100
Heat treatment is performed for 20 minutes in an oven at 160 [° C.] under a load of 0 [g / den]. Then, the load is removed, and after cooling, a load of 1/30 [g / den] is applied again and the length L2 [cm] at that time is measured. Boiling water shrinkage and SHD
(Dry heat 160 ° C. shrinkage) is calculated as follows. Shrinkage rate of boiling water [%] = {(L0-l1) / L0} × 100 SHD [%] = {(L0-L2) / L0} × 100

[Di] (degree of entanglement [ke / m]) Take out a thread of an appropriate length, and take 1/1000 [g /
den] and suspend vertically. Then, a suitable needle is put in the thread, and it is slowly lifted up, and the distance 1 [cm] moved until the load is lifted is measured 20 times, and the average value L [cm] is calculated. Di is the following formula,
It is calculated. Di [ke / m] = 100 / (2 × L)

[0022]

[Examples] Specific examples will be described below.

[0023]

Example 1 Polyethylene terephthalate semi-dal resin was melted, melted and discharged from a nozzle having a circular discharge hole, and drawn at a speed of 3000 m / min to obtain a highly oriented unstretched polyester multifilament of 33 denier / 24 filament. The highly oriented unstretched polyester multifilament was stretched 1.65 times while heating at 78 ° C. to obtain a highly densified polyester stretched multifilament of 20 denier / 24 filament. 45% at a yarn speed of 500 m / min using a non-contact type heater in which the high shrinkage polyester stretched multifilament is heated to 190 ° C.
Was subjected to relaxation heat treatment to obtain a relaxation heat-treated polyester multifilament having 29 denier / 24 filaments.
SHD of the relaxation heat-treated polyester multifilament
Was -5.0 [%]. Separately, polyethylene terephthalate semi-dal resin is melt-spun and stretched to give 73
Denier / 18 filament with SHD of 18.0 [%]
A high shrinkage polyester multifilament was obtained. Separately, 10 [mol%] of isophthalic acid was used together with terephthalic acid with respect to the total acid component, and the obtained isophthalic acid component was copolymerized with polyethylene terephthalate semi-dal resin and the total weight was 9.0 [wt%]. Average molecular weight of 2
0000 polyethylene glycol was melt-blended to obtain a highly soluble polyester having high solubility in an alkali hot aqueous solution. The easily soluble polyester is melted and discharged from a nozzle having a circular discharge hole, spun, and stretch-heat set to have a SHD of 1 with 29 denier / 12 filaments.
0.0 [%] of easily soluble polyester multifilament was obtained. The easily soluble polyester multifilament had a dissolution rate 40 times higher than that of the relaxation heat-treated polyester multifilament and the high-shrinkage polyester multifilament in an alkaline hot aqueous solution. These three types of multifilaments are aligned and subjected to fluid entanglement treatment using an interlacer nozzle.
A denier / 54 filament composite yarn was obtained. Di of the composite yarn was 50 [ke / m]. S direction 1 to the composite yarn
Twisted yarn of 200 [T / m] was applied, and wet heat setting was applied at 65 [° C.] for 40 minutes. The twisted set yarn was used as warp and plain woven with a warp density of 80 [pieces / inch] and a weft density of 78 [pieces / inch] to obtain a raw fabric. After relaxing and presetting the greige by a conventional method, the difference in heat shrinkage between the filaments constituting the composite yarn is revealed to make it bulky,
Alkali hot water treatment was applied to reduce the amount by 30% by weight. After that, it was dyed with a disperse dye and subjected to a final set to obtain a dyed fabric. When the dyed fabric and the raw fabric were enlarged and observed with a scanning electron microscope, all the easily soluble polyester multifilaments were eluted and removed. The dyed fabric had a favorable texture in softness, swelling and tightness.

[0024]

COMPARATIVE EXAMPLE 1 The relaxation heat-treated polyester multifilament of Example 1 was not used, but instead, 29 denier /
Polyethylene terephthalate semi-dull drawn heat set multifilament having 24 filaments and SHD of 5.0% was used and subjected to fluid entanglement treatment in the same manner as in Example 1, and 13
A composite yarn of 2 denier / 54 filaments was obtained. A dyed fabric was obtained from the composite yarn in the same manner as in Example 1. The dyed fabric was inferior to the dyed fabric of Example 1 in terms of surface soft touch and swelling feeling.

[0025]

Comparative Example 2 In place of the easily soluble polyester multifilament used in Example 1, a polyethylene terephthalate semidal resin 29 denier / 12 filament SHD 10.0% multifilament was used. A composite yarn of 132 denier / 54 filaments was obtained in the same manner as in 1. Alkali hot water treatment was carried out in the same manner as in Example 1 to obtain a dyed fabric with a weight reduction rate of 30% by weight, but the swelling feeling was inferior to that of Example 1.

[0026]

[Comparative Example 3] Compared to Example 1, three types of multifilaments were aligned, combined, and wound without fluid entanglement treatment to obtain a composite yarn. The composite yarn had many twists and yarn breakages in the weaving process, and although it contained the easily soluble polyester multifilament, the swelling feeling after dyeing was not sufficient.

[0027]

Example 2 Instead of the easily-dissolvable polyester multifilament used in Example 1, the easily-dissolvable polyester multifilament of the same denier / filament having a hollow ratio of 30% discharged from a C-shaped nozzle hole was used. A composite yarn was obtained to obtain a dyed fabric. The dyed fabric was preferable to the dyed fabric of Example 1 in that the swelling feeling was further improved.

[0028]

Example 3 Instead of the easily-dissolvable polyester multifilament of Example 2, the easily-dissolvable polyester multifilament having the same denier / filament having four hollow portions and a total hollow ratio of 30% was used. A composite yarn was obtained. The easily soluble polyester multifilament in the composite yarn retained four hollow portions even after the twisted yarn, and the dyed fabric had a further improved swelling feeling than the dyed fabric of Example 2.

[0029]

Example 4 A polyester multifilament having 73 denier / 18 filaments of Example 1 and an SHD of 18.0 [%] and an easily soluble polyester multifilament of Example 3 were aligned, and an interlacer nozzle was used. Was entangled by a fluid such that The 102-denier / 30-filament fluid-entangled yarn and the 29-denier / 24-filament relaxation heat-treated yarn of Example 1 were subjected to fluid-entanglement treatment with an aligner nozzle to obtain a composite yarn having a Di of 50 / m. A dyed fabric was obtained in the same manner as in Example 1. The composite yarn constituting the dyed fabric was observed with a scanning electron microscope to find that it was 73 denier / 1.
The voids were evenly provided in the 8-filament polyester multifilament, and a bulging feeling was found in Example 3.
It was a preferable one which was further improved over the dyeing processing fabric of No. 1.

[0030]

[Example 5] The fluid-entangled yarn of 102 denier / 30 filaments and the relaxation heat-treated yarn of 29 denier / 24 filaments of Example 4 were subjected to relaxation heat treatment yarns 15 [ %] Fluid entanglement treatment was performed so as to supply excessively to obtain a composite yarn. Di was 85 / m. The dyed fabric obtained from the composite yarn was extremely preferable as compared with the dyed fabric of Example 4 in that the softness and swelling of the surface were further improved.

[0031]

The polyester composite yarn of the present invention contains the easily soluble polyester multifilament and the heat-extensible polyester multifilament. Therefore, the conventional composite shrinkage is caused by the heat treatment during the dyeing process and the alkali hot water treatment. It is possible to provide a soft feeling, a feeling of bulging and a feeling of tightness, which is unique to mixed fiber. Further, since the fluid is entangled, it is excellent in the passage property in the subsequent process. INDUSTRIAL APPLICABILITY The polyester composite yarn of the present invention has a wide range of uses as a woven or knitted fabric such as clothing and other daily life materials.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI D01F 6/62 D01F 6/62 303K D06M 101: 32 D06M 101: 32 (56) Reference JP-A-5-279933 (JP, A) ) JP-A-6-116826 (JP, A) JP-A-4-370233 (JP, A) JP-A-4-333634 (JP, A) JP-A-57-21529 (JP, A) JP-A-7- 324240 (JP, A) JP 7-316940 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) D02G 1/18 D02G 3/04 D03D 15/00 D06M 11/38 D01F 6/62 D06M 101: 32

Claims (8)

(57) [Claims] 1. A composite yarn containing at least polyester multifilaments A to C satisfying the following heat shrinkage characteristics and having a degree of entanglement of 20 to 100 co / m, wherein the polyester multifilament B is an alkali with respect to A and C. A polyester composite yarn having a dissolution rate of 5 times or more in a hot aqueous solution. SHD (A) ≤ 0 [%] ……………………… (1) SHD (B)> 0 [%] ……………………… (2) SHD (C) > 0 [%] ………………………… (3) (However, SHD (A), SHD (B), SHD (C) are the dry heat of polyester multifilaments A, B, C, respectively. Indicates the shrinkage rate at ° C.) 2. The polyester composite yarn according to claim 1, wherein the filaments constituting the polyester multifilament B have a monofilament denier of 1.0 denier or more. 3. The polyester composite yarn according to claim 1, wherein the cross-sectional shape of the filaments constituting the polyester multifilament B is a hollow cross section. 4. The polyester composite yarn according to claim 1, wherein the filaments constituting the polyester multifilament B have a hollow cross section having a plurality of hollow portions. 5. The polyester composite yarn according to claim 1, wherein the polyester multifilament B is contained in an amount of 2 to 30% by weight based on the composite yarn. 6. Polyester multifilaments B and C
6. The polyester composite yarn according to claim 1, wherein the respective constituent filaments are mixed and mixed with each other. 7. The polyester multifilament A is located relatively in the outer peripheral portion with respect to the other constituent polyester multifilaments.
The polyester composite yarn according to item. 8. A polyester multifilament A to C satisfying the following heat shrinkage characteristics is entangled to 20 to 100 k / m.
2. A method for producing a polyester woven or knitted fabric, which comprises subjecting the composite yarn to fluid entanglement to obtain a composite yarn, and then eluting and removing the polyester multifilament B by alkaline hot water treatment after weaving and weaving the composite yarn. SHD (A) ≤ 0 [%] ……………………… (1) SHD (B)> 0 [%] ……………………… (2) SHD (C) > 0 [%] ………………………… (3) (However, SHD (A), SHD (B), SHD (C) are the dry heat of polyester multifilaments A, B, C, respectively. Indicates the shrinkage rate at ° C.)