JPH04289219A - Light-weight and vividly dyeable polyester multifilament yarn - Google Patents

Abstract

PURPOSE:To obtain a polyester multifilament having sufficient strength, capable of dyeing vividly in light weight and having excellent handle. CONSTITUTION:In a multifilament yarn consisting of cation dye dyeable polyester having >=0.6 intrinsic viscosity, 2.0-5.0 denier single fiber fineness, >=20% hollow ratio and >=23.0 silk factor (strength X elongation<1/2>) are simultaneously satisfied. The multifilament yarn is especially suitable as a raw material for sport textile, because the yarn can be dyed vividly in light weight and has also sufficient strength.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a modified polyester multifilament yarn that can be vividly dyed with cationic dyes and is lightweight. The present invention relates to a lightweight polyester multifilament yarn that is strong, has excellent whiteness, and has good hollow formation properties despite having a hollow ratio of 20% or more.

0002

BACKGROUND OF THE INVENTION Polyester fibers have many excellent properties and are therefore widely used in clothing and non-clothing fields. However, it is heavier than natural fibers and has low water absorption, so it is not necessarily a comfortable material to wear. In addition, in terms of dyeing clarity, nylon
Inferior to acetate etc.

Conventionally, various attempts have been made to improve the above-mentioned drawbacks, and recently, supernatural fibers called new synthetic fibers, such as ultra-fine fibers, ultra-bulky fibers, and super-draped fibers, have been developed. However, with changes in social trends and an increasing trend toward comfortable living due to concerns about lifestyle and health, there is an increasing demand for clothing materials that provide a sense of comfort, and polyester fibers still do not satisfy these needs. The current situation is that there is no such thing.

[0004] For example, the required properties in the field of sports clothing include light weight and heat retention, brightness in dyeing, and high strength.
JP-A-1-162822 discloses that dyeing clarity and high strength can be achieved by copolymerizing a specific cationic dye dye-enabling agent and simultaneously adding a quaternary ammonium salt as a stabilizer. . On the other hand, regarding filament yarns with high hollowness to improve lightweight heat retention, a bulky yarn with a hollowness of 40 to 90% is proposed in JP-A-62-215032, and JP-A-50-100310
The publication proposes a method of stabilizing the hollow formation property by blending oxalic acid into a thermoplastic polymer.

[0005] However, the filament yarns that have been proposed have various drawbacks, such as poor lightness and insufficient dyeing clarity due to light dyeing (decreased apparent dye density) due to hollow pores. It still has.

[0006]

OBJECTS OF THE INVENTION The present invention was made in view of the drawbacks of the above-mentioned prior art, and its purpose is to provide a polyester multifilament yarn that can be vividly dyed and is lightweight (has a light apparent specific gravity), especially An object of the present invention is to provide a filament yarn that can exhibit excellent effects in the field of sports clothing.

[0007]

[Structure of the Invention] As a result of intensive studies to achieve the above object, the present inventors have discovered that by forming hollow fibers from cationic dye-dyeable polyester with a high degree of polymerization, the present inventors have improved lightness, color clarity, and mechanical properties. The inventors have discovered that the characteristics can be improved at the same time and have arrived at the present invention.

That is, in the present invention, the intrinsic viscosity [η] is 0.
．． A multifilament yarn made of polyester dyeable with cationic dyes of 6 or more, the multifilament yarn has a single fiber fineness of 2.0 to 5.0 denier, a hollowness ratio of 20% or more, and a silk factor of 23 or more. It is a lightweight bright dyeable polyester multifilament yarn (
However, the silk factor is calculated from the breaking strength S (g/de) and breaking elongation L (%) of the multifilament, S×L1
/2).

It is important that substantially all of the single fibers constituting the multifilament yarn of the present invention have hollow portions. The larger the hollowness ratio is, the greater the weight reduction effect will be, but if it is too large, light scattering will increase and the color will tend to become lighter, and the spinning stability (hollow cracks, yarn breakage, etc.) will also tend to decrease. Therefore, it is desirable to set it to 20% or more, preferably about 30 to 50%.

[0010] In addition, when the single fiber fineness is small, the hollow forming property tends to decrease, while when it is large, the texture tends to become hard, so it is recommended to set it in the range of 2.0 to 5.0 denier. preferable. The total fineness of the multifilament yarn may be about 20 to 300 deniers, which is generally used for clothing. On the other hand, the cross-sectional shape of the single fibers does not need to be particularly limited, and may be either round or irregularly shaped (triangular, square, pentagonal, hexagonal, oblate), or may be of the same shape or a mixture of different shapes. You may do so.

[0011] The strength and elongation of multifilament yarns does not need to be particularly limited if the purpose is simply to reduce the weight, but it becomes an important factor when used in the field of sports clothing, and the silk factor (breaking strength (g/ de) x elongation (%) 1
/2) must be at least 23, preferably 25 or more, particularly 28 or more. If it is less than 23, the mechanical properties are insufficient, resulting in poor durability when used as a fabric for severe use.

[0012] Furthermore, the polyester constituting the multifilament yarn of the present invention must be dyeable with cationic dyes and have an intrinsic viscosity of 0.6 or more. If the dye is non-stainable with cationic dyes and can be dyed only with disperse dyes, the effect of dyeing clarity will not be achieved, which is not preferable. On the other hand, when the intrinsic viscosity is less than 0.6, it is not only difficult to obtain a hollow fiber with a high hollowness ratio of 20% or more, but also
A filament yarn with a silk factor of 23 or more is difficult to obtain, so it is not preferred. On the other hand, if the intrinsic viscosity is too high, the increase in pack pressure during spinning will be too large and the stringiness will tend to deteriorate, so it is preferably 0.64 to 0.8, particularly 0.7 to 0.8. It is desirable that the

The polyester used in the present invention has terephthalic acid as the main acid component, and at least one glycol, preferably at least one alkylene glycol selected from ethylene glycol, trimethylene glycol, and tetramethylene glycol as the glycol component. The main target is a polyester copolymerized with a cationic dye dyeing agent as described above.

[0014] It may also be a polyester in which a part of the terephthalic acid component is replaced with another difunctional carboxylic acid component, and/or a part of the glycol component is replaced with the above-mentioned glycol or other diol component other than the main component. It may also be a polyester substituted with.

Examples of the difunctional carboxylic acids other than terephthalic acid used here include isophthalic acid, naphthalene dicarboxylic acid, diphenyl dicarboxylic acid, diphenoxyethane dicarboxylic acid, β-hydroxyethoxybenzoic acid, and p-oxybenzoic acid. , adipic acid, sebacic acid,
Examples include aromatic, aliphatic, and alicyclic difunctional carboxylic acids such as 1,4-cyclohexanedicarboxylic acid. Furthermore, isophthalic acid having a sulfonic acid metal base such as 5-sodium sulfoisophthalic acid may be used as a copolymerization component within a range that substantially achieves the effects of the present invention.

Examples of diol compounds other than the above-mentioned glycols include aliphatic, alicyclic, and aromatic diol compounds such as cyclohexane-1,4-dimethanol, neopentyl glycol, bisphenol A, and bisphenol S, and polyoxy Examples include alkylene glycol.

[0017] Such polyesters can be synthesized by any method. For example, in the case of polyethylene terephthalate, usually terephthalic acid and ethylene glycol are directly esterified, a lower alkyl ester of terephthalic acid such as dimethyl terephthalate is transesterified with ethylene glycol, or terephthalic acid and ethylene oxide are transesterified. The first stage reaction is to react with the glycol ester of terephthalic acid and/or its low polymer, and the first stage reaction product is heated under reduced pressure to polymerize until the desired degree of polymerization is reached. It is produced by a second step of condensation reaction. In the present invention, the copolymerization component used for dyeability with cationic dyes is preferably a sulfonic acid phosphonium salt represented by the following general formula (I).

[0018]

embedded image In the formula, A represents an aromatic group or an aliphatic group, and among them, an aromatic group is preferable. X1 represents an ester-forming functional group, and specific examples include

[0019]

embedded image (wherein, R' is a lower alkyl group or a phenyl group, a and d are an integer of 1 or more, and b is an integer of 2 or more). X2 represents an ester-forming functional group or a hydrogen atom that is the same as or different from X1, and is preferably an ester-forming functional group. R1,R
2, R3 and R4 are the same or different groups selected from the group consisting of alkyl groups and aryl groups. n is a positive integer.

Preferred specific examples of the sulfonic acid phosphonium salts include 3,5-dicarboxybenzenesulfonic acid tetrabutylphosphonium salt, 3,5-dicarboxybenzenesulfonic acid ethyltributylphosphonium salt, and 3,5-dicarboxybenzene. Benzyltributylphosphonium sulfonate salt, 3,5-dicarboxybenzenesulfonic acid phenyltributylphosphonium salt, 3,
5-dicarboxybenzenesulfonic acid tetraphenylphosphonium salt, 3,5-dicarboxybenzenesulfonic acid butyltriphenylphosphonium salt, 3,5-dicarboxybenzenesulfonic acid benzyltriphenylphosphonium salt, 3,5-dicarbomethoxybenzene Tetrabutylphosphonium sulfonate salt, ethyltributylphosphonium 3,5-dicarbomethoxybenzenesulfonate salt, benzyltributylphosphonium 3,5-dicarbomethoxybenzenesulfonate salt, phenyltributylphosphonium 3,5-dicarbomethoxybenzenesulfonate salt, 3,5-dicarbomethoxybenzenesulfonic acid tetraphenylphosphonium salt, 3,5-dicarbomethoxybenzenesulfonic acid ethyltriphenylphosphonium salt, 3,5-dicarbomethoxybenzenesulfonic acid butyltriphenylphosphonium salt, 3 , 5-dicarbomethoxybenzenesulfonic acid benzyltriphenylphosphonium salt, 3-carboxybenzenesulfonic acid tetrabutylphosphonium salt, 3-carboxybenzenesulfonic acid tetraphenylphosphonium salt, 3-carbomethoxybenzenesulfonic acid tetrabutylphosphonium salt, 3 -Carbomethoxybenzenesulfonic acid tetraphenylphosphonium salt, 3,5-di(β-hydroxyethoxycarbonyl)benzenesulfonic acid tetrabutylphosphonium salt, 3,5-di(β-hydroxyethoxycarbonyl)benzenesulfonic acid tetraphenylphosphonium salt , 3-
(β-hydroxyethoxycarbonyl)benzenesulfonic acid tetrabutylphosphonium salt, 3-(β-hydroxyethoxycarbonyl)benzenesulfonic acid tetraphenylphosphonium salt, 4-hydroxyethoxybenzenesulfonic acid tetrabutylphosphonium salt, 2,6-dicarboxy Examples include naphthalene-4-sulfonic acid tetrabutylphosphonium salt, α-tetrabutylphosphonium sulfosuccinic acid, and the like. The above sulfonic acid phosphonium salts may be used alone or in combination of two or more.

[0021] In order to copolymerize the sulfonic acid phosphonium salt into a polyester, it may be added at any stage before the synthesis of the polyester described above is completed, preferably at a stage before the beginning of the second stage reaction. The proportion of the sulfonic acid phosphonium salt copolymerized with the polyester is in the range of 0.1 to 10 mol%, based on the bifunctional carboxylic acid component (excluding the sulfonate) constituting the polyester, and is 0.5 to 5% by mole. A mole % range is preferred. Copolymerization ratio is 0
．． If it is less than 1 mol%, the resulting modified polyester fiber will have insufficient dyeability with cationic dyes,
When the amount exceeds mol%, the cationic dyeability no longer shows any significant improvement, and the physical properties of the polyester deteriorate on the contrary, making it difficult to achieve the object of the present invention.

[0022] In producing the above-mentioned polyester, it is preferable to add a quaternary onium salt. As the quaternary onium salt, all quaternary onium salts that are substantially non-reactive with the polyester are used. Such quaternary onium salts include quaternary ammonium salts, quaternary phosphonium salts, etc. Among them, quaternary ammonium salts can be obtained at low cost compared to other quaternary onium salts, so they are inexpensive. From this viewpoint, it is preferable to use a quaternary ammonium salt industrially.

[0023] If the amount of the quaternary onium salt used is too small, the effect of improving heat resistance will be insufficient, and if it is too large, the heat resistance will deteriorate, and in addition, the resulting polyester and molded There is a noticeable tendency for objects to turn yellowish brown. Therefore, the amount of quaternary onium salt to be used is 0.1 to 0.1 to
The range of 20 mol% is preferable, especially 1 to 10 mol%
A range of is particularly preferred.

Next, a method for producing the above-mentioned polyester multifilament yarn will be explained.

FIGS. 1 and 2 are schematic front views of a spinning (drawing) apparatus used to produce the lightweight bright polyester multifilament yarn of the present invention. Also,
FIG. 3 is a schematic diagram of a stretching device.

In the present invention, for example, the above-mentioned cationic dye dyeable polyester is melt-extruded from a spinneret incorporated in the spinning head shown in FIG. The undrawn yarn is wound up by a winding unit 8 via a take-up roll.

[0027] At this time, since the higher the viscosity of the molten polymer, the greater the hollowness ratio that is formed, it is desirable to perform the spinning at as low a temperature as possible without impairing the physical properties of the resulting multifilament yarn. Therefore, while ordinary polyester filament yarns are spun at a temperature 5 to 6 degrees Celsius higher than the limit temperature for developing weak yarns, in the present invention, the yarns are spun at temperatures that are 1 to 2 degrees Celsius higher than the limit temperature for developing weak yarns. It is preferable to set the temperature to eye temperature (however, the limit temperature for developing weak yarn refers to the spinning temperature at which the silk factor begins to decrease rapidly)
.

Furthermore, in the process of cooling and solidifying the molten polymer, rapid cooling is preferred in order to improve the hollowness ratio. However, since the spinning temperature is close to the spinning limit temperature, it is important to prevent the spinneret from being cooled by cooling air.As shown in Figure 1, the spinneret leaves holes through which the yarn passes. It is desirable that the area be covered with a shutter. It is preferable to keep the distance from the spinneret to the shutter (hot zone length) as short as possible from the perspective of improving the hollowness ratio, but if it is too short, the spinneret itself will be cooled and problems such as uneven discharge and yarn breakage will occur. It is desirable that the length be about 30 to 50 mm because it makes it easier to form the mold, but if it is too long, the solidification point will become long and it will be difficult to obtain the desired hollowness ratio.

[0029] In addition, the cooling air volume (wind speed) is also significantly affected by the solidification efficiency, and the wind speed at a position 50 mm below the cap is 30~30 mm.
It is desirable to set the speed to about 50 cm/sec. If it is too low, the hollowness ratio will decrease, and if it is too high, yarn waviness will tend to occur and the uniformity of the fibers in the length direction will deteriorate, which is not preferable. The length of the cooling air outlet is 300 to 1000 mm, preferably 500 to 600 m.
It is sufficient if it is about m.

[0030] In order to stably obtain a high-hollowness yarn in terms of both quality and spinning process, the specifications of the spinneret are also an important requirement. The shape of the die for obtaining hollow fibers usually has a plurality of slit-shaped discharge holes arranged in a ring, but in order to increase the hollowness ratio, the area surrounded by the slit-shaped discharge holes (referred to as the hollow hole area) must be It has to be widened. the result,
If the width of the discharge slit is kept constant, the discharge hole area will increase, which will reduce the discharge linear velocity and make it difficult to increase the hollowness ratio.The draft will also increase and yarn breakage will occur during yarn spinning. It becomes easier. Therefore, in the present invention, the portion surrounded by the plurality of slits has an inner diameter (hollow hole inner diameter: PCD) of 1.0 mm or more, preferably 1.0 mm or more.
．． It should be circular with a diameter of 2 mm or more, and the area per discharge hole should be 0.
It is desirable to set the draft to about 200 or less by setting it to 2 mm2 or less.

In the present invention, the undrawn yarn may be directly stretched using, for example, the apparatus shown in FIG. It may be stretched by hand.

[0032]

[Examples] The present invention will now be explained in more detail with reference to Examples. Note that each characteristic value was determined according to the following method. 1. Intrinsic viscosity was measured using an orthochlorophenol solution at 35°C. 2. It was determined from the following formula from the breaking strength S (g/de) and breaking elongation L (%) of the silk factor multifilament. Silk factor = S x L1/2 3. Hollow Ratio From the cross-sectional photograph of the hollow fiber, the area occupied by the outer periphery of the fiber cross section (S0) and the area of the hollow part (S1) are determined, respectively, and S
The hollow ratio was 1/S0×100. 4. K/S value Multifilament yarn was knitted into a tube and dyed using 3% OWF dye at 130°C for 40 minutes. K of the obtained dyed cloth
/S value was measured using a Macbeth colorimeter manufactured by Kanebo Co., Ltd. 5. Drape coefficient A plain weave fabric was obtained using multifilament yarns as double yarns and weaving density of 85 threads/inch and 80 threads/inch for the warp and weft, respectively, and JIS with a drape tester manufactured by Shimadzu Corporation.
Measured according to the N1096 method.

[0033]

[Example 1] 100 parts of dimethyl terephthalate, 60 parts of ethylene glycol, 0.03 part of manganese acetate tetrahydrate, 0.009 part of cobalt acetate tetrahydrate as a coloring agent, 1.7 mol based on dimethyl terephthalate. 0.05 per % amount of 3,5-dicarbomethoxybenzenesulfonic acid tetra-n-butylphosphonium salt and dimethyl terephthalate
A mol % amount of tetra-n-butylphosphonium bromide was charged into a transesterification reactor, and the temperature was raised from 140°C to 220°C over 3 hours under a nitrogen gas atmosphere to carry out the transesterification reaction while distilling the generated methanol out of the system. The resulting product was treated with 0.0% aqueous 56% orthophosphoric acid solution as a stabilizer.
At the same time, expulsion of excess ethylene glycol by heating was started, and 10 minutes later, 0.04 part of antimony trioxide was added as a polymerization catalyst. When the internal temperature reached 240°C, expulsion of ethylene glycol was completed and the reaction product was transferred to a polymerization vessel. Next, the reaction was carried out under normal pressure while increasing the temperature until the internal temperature reached 260°C, and then the temperature was increased to 760 mm over 1 hour.
The pressure was reduced from Hg to 1 mmHg, and at the same time, the internal temperature was raised to 280°C over 1 hour and 30 minutes. The polymerization was further carried out for 2 hours under a reduced pressure of 1 mmHg or less at a polymerization temperature of 280° C., and then the vacuum was broken with nitrogen gas to terminate the polymerization. The resulting polymer had a softening point (sp) of 253.5°C and an intrinsic viscosity [η] of 0.
．． It was 672.

[0034] This polymer was processed using the spinning equipment shown in Fig.
Melted at 0°C, using a spinneret with a hollow pore inner diameter (PCD) of 1.3 mm, slit width of 0.09 mm, pore area of 0.175 mm2, and 12 holes, and a hot zone length of 40 mm.
, While cooling at a cooling air temperature of 27°C and a wind speed of 40 cm/sec,
Towing speed 1300m/min, pulling 87.5de/1
2fil of undrawn yarn was obtained, and then, while heat-set with a heating roll temperature of 86°C and a heating heater temperature of 180°C in the drawing equipment shown in FIG. 3, it was stretched at a draw ratio of 2.5 times to 600 m/
It was wound at a winding speed of 1 minute. The obtained single yarn denier was 2.9 denier, the strength was 4.6 g/de, the silk factor was 27, the average hollowness of 12 fil was 32%, and the evenness u% was 0.8%.

The obtained multifilament was knitted into a tube and dyed with cationic dye.

[0036]

When dyed black using [Chemical Formula 3], the K/S value was 37. Further, the drape coefficient of the plain weave was 0.372, which was good.

[0037] Also, the fabric was placed in a container containing water for 30 minutes.
It remained floating even after being left for a long time, and was extremely lightweight.

[0038]

[Comparative Example 1] Softening point 256°C, intrinsic viscosity [η
]0.64 using polyethylene terephthalate, 2
Melted at 85°C, hollow hole inner diameter (PCD) 1.31 mm,
Slit width 0.09mm, hole area 0.175mm2,
Using a spinneret with 24 holes, the hot zone length was 4.
0mm, cooling air temperature 27℃, wind speed 30cm/sec and pulling at 1000m/min 204.4de/24f
An undrawn yarn of il was obtained, and then, as in Example 1, it was heat-set at a heating roll temperature of 86°C and a heating heater temperature of 180°C, and was stretched at a draw ratio of 2.8 times and wound at a rate of 600 m/min. The single yarn denier of the obtained yarn was 3.0 denier, the strength was 4.7 g/de, and the silk factor was 26.6, 1.
The average hollowness ratio of 2fil was 41%. This multifilament yarn is knitted into a tube and disperse dyes are produced.

[0039]

When dyed with [Chemical Formula 4] at 130°C for 45 minutes, the K/S value was 30, and the clarity was still insufficient.

[0040]

[Example 2] Softening point 254 obtained by the same method as Example 1
℃, cationic dye-dyeable polyethylene terephthalate with an intrinsic viscosity [η] of 0.70 was spun and drawn under the same spinning conditions as in Example 1, and the yarn was 35 de/12 fil, single yarn denier 2.9 denier, and strength 4.8 g. A multifilament yarn with a silk factor of 28.8, an average hollowness of 12fil of 40%, and an evenness u% of 0.9% was obtained. Next, the obtained multifilament yarn was dyed after tube knitting in the same manner as in Example 1 to obtain a K/S value of 36. Similarly, when the drape coefficient was measured using a plain woven fabric having warp and weft weave densities of 85 threads/inch and 80 threads/inch, respectively, the drape coefficient was 0.386.

[0041]

[Comparative Example 2] The same cationic dyeable polyester used in Example 1 was melted at 280°C in the same manner as in Example 1, and the hollow pore inner diameter (PCD) was 1.3 mm and the slit width was 0.09 mm.
Using a spinneret with a hole area of 0.170 mm2 and 24 holes, the hot zone length was 43 mm and the cooling air temperature was 27°C.
, while cooling at a wind speed of 30 cm/sec, the stringing speed was 1000 m/sec.
The undrawn yarn of 100.8 de/24 fil was obtained by pulling it off for 10 minutes, and then the heating roll temperature was 86° C. in the same manner as in Example 1.
While heat-setting at a heating heater temperature of 180° C., the film was stretched at a stretching ratio of 2.8 times and wound up at a speed of 600 m/min. The single yarn denier of the obtained multifilament yarn is 1.5
Denier, strength 4.6g/de, silk factor 2
The average hollowness ratio of 5.1 and 24fil was 24%,
Evens u% was poor at 2.3%, and the occurrence rate of stretch wrap was extremely high, resulting in poor spinning stability.

[0042]

[Comparative Example 3] The polymer obtained in Example 1 was melted at 285°C using the equipment shown in Figure 2, and the hollow pore inner diameter (PCD) was 1.
3mm, slit width 0.1mm, hole area 0.18mm2
Extruded from a spinneret with 12 holes, hot zone length 43 mm, cooling air temperature 27 °C, wind speed 35 cm/sec, heated take-up roll (105 °C x 6 turns)
The yarn was spun at a speed of 1000 m/min through a drawing heating roll (130°C x 6 turns) and simultaneously heat set while being stretched to 2.9 times, and then wound up to 72 de/12 fil.
A multifilament yarn having a single yarn denier of 6 denier, a strength of 4.9 g/de, a silk factor of 26.8, and an average hollowness of 12 fil of 36% was obtained. This multifilament yarn was dyed in the same manner as in Example 1, and the K/S value was 29. On the other hand, the drape coefficient was 0.48, which was less flexible than Examples 1 and 2.

[0043]

[Comparative Example 4] Polyethylene terephthalate obtained by copolymerizing 2.6 mol% of 5-sodium sulfoisophthalic acid component with respect to terephthalic acid component: Softening point 257°C, intrinsic viscosity 0
．． 485, with the apparatus shown in Figure 2, at a spinning temperature of 275°C.
, hollow hole inner diameter (PCD) 1.31mm, slit width 0.
09mm, hole area 0.175mm2, extrusion from a spinneret with 12 holes, hot zone length 40mm, cooling air temperature 27°C, cooling air speed 30cm/sec,
72 denier/12f taken at a taking speed of 1300m/min
An undrawn yarn of il was obtained. This undrawn yarn was drawn 2.4 times using the device shown in Figure 3, and wound at 600 m/min while heating at a heater temperature of 180°C to 30 denier/12 f.
il, single yarn denier 2.5 denier, strength 3.9 g/d
A multifilament yarn of No. e was obtained, but it had a silk factor of 22.7 and a hollow ratio of 15%, which was poor in toughness and lightness.

[0044]

[Comparative Example 5] The polyethylene terephthalate having an intrinsic viscosity of 0.64 used in Comparative Example 1 was melted at 290°C, and the pore size was 0.64.
3 mm, hole area 0.07 mm2, extruded from a solid spinneret with 12 holes, hot zone length 90 mm, cooling air temperature 27°C, cooling air speed 28 cm/sec, take-up speed 13
The yarn was drawn at a speed of 00 m/min to obtain an undrawn yarn of 81.2 de/12 fil. This undrawn yarn was stretched for 600 m by the stretching device shown in Fig. 3 at a heating roll temperature of 86°C, a stretching ratio of 2.8 times, and a heat setting heater temperature of 180°C.
Multifilament yarn of 30 denier/12 fil, single yarn denier 2.5 denier, strength 5.2 g
/de, a solid yarn with a silk factor of 30 was obtained. When the K/S value was determined in the same manner as Comparative Example 1, it was found to be 35
However, because it was dyed with a disperse dye, it lacked clarity. Furthermore, this product sank when placed in water and was not lightweight.

[0045] The above results are shown in Table 1. In addition,
Judgment for each evaluation item was made in accordance with the following. Thread spinning property: Threads that could be stably spun were rated as good (O), and cases where fuzzing, yarn breakage, etc. occurred frequently were rated as poor (x). K/S value comparison example 5 is taken as the standard, and anything larger than this is considered good (○).
, equivalent (△), and inferior (×). Drapability Comparative Example 5 was used as the standard, and the K/S value was as good (○
), equivalent (△), and defective (x). Lightweight Hollowness ratio of 30% or more is good (○), 20 to 30% (△)
, less than 20% was indicated as poor (×).

[0046]

[Table 1]

[0047]

[Effects of the Invention] The polyester multifilament yarn of the present invention described above has excellent bright dyeing properties because it is dyed with cationic dyes even though it is a hollow fiber with a high hollowness ratio. It has the property of floating on water. Therefore, it is particularly suitable as a lightweight and comfortable material for the field of sports clothing, and its industrial value is extremely large.

[Brief explanation of the drawing]

FIG. 1 is a schematic front view of a spinning device used in the present invention.

FIG. 2 is a schematic front view of a spinning and drawing apparatus used in the present invention.

FIG. 3 is a schematic front view of a stretching device used in the present invention.

[Explanation of symbols] 1 Spinning head 2 Hot zone 3 Shutter 4 Cooling air outlet 5 Oiling roll 6 Take-up roll 1 7 Take-up roll 2 8 Winding unit 9 Winding package 10 Separate roll 11 Separate roll 12 Unstretched package 13 Feed roll 14 Heating roll 15 Separate roll 16 Heater 17 Stretch roll 18 Separate roll 19 Traverse ring 20 Winding pirn Y Spun yarn

Claims (1)

[Claims] 1. A multifilament yarn made of polyester having an intrinsic viscosity [η] of 0.6 or more and dyeable with cationic dyes, the multifilament yarn having a single fiber fineness of 2.
．． A lightweight brightly dyeable polyester multifilament yarn having a denier of 0 to 5.0, a hollowness ratio of 20% or more, and a silk factor of 23 or more. (However, the silk factor is calculated from the breaking strength S (g/de) and breaking elongation L (%) of the multifilament as S×L1/2.)