JPH05263316A - Conjugate yarn - Google Patents

Abstract

PURPOSE:To obtain conjugate yarn, composed of a water-soluble polyester, a thermoplastic fiber-forming polymer and a polyurethane, having the components mutually brought into contact in the yarn cross section, excellent in handleability, capable of simplifying the process and good in strength, stretchability and heat resistance. CONSTITUTION:This conjugate yarn is obtained by melting a water-soluble polyester (component E) composed of (A) 5-20mol% aromatic dicarboxylic acid (ester-forming derivative) having sulfonate, (B) >=55mol% aromatic dicarboxylic acid (ester-forming derivative) except the component (A), (C) an alicyclic dicarboxylic acid (ester-forming derivative) and (D) an aliphatic dicarboxylic acid (ester-forming derivative) as an acid component and >=50mol% ethylene glycol as a glycol component, a thermoplastic fiber-forming polymer (component F) and a polyurethane (component U) in separate extruders, leading the melt to a conjugate spinneret, spinning and drawing the resultant yarn. Thereby, the component (E) is brought into contact with both the components (F) and (U) at one or more places in the yarn cross section.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a novel polyurethane-based composite yarn.

[0002]

2. Description of the Related Art Conventionally, there is a method in which a polyurethane elastic yarn is wrapped around a bulky processed yarn as a covered yarn to form a covered elastic yarn. As the manufacturing method, there are a method using a covering machine using a hollow spindle, a method of aligning and twisting, and the like.

Further, Japanese Patent Publication No. 56-5850 describes a method in which the temperature of false twisting is increased so that the polyurethane elastic yarn is not easily separated by adhering or fusing. In addition, there is also known a method in which a polyurethane elastic yarn is aligned with a filament to be a covering yarn, and at the same time false twisting is performed. Furthermore, JP-A-63-1454
In JP-A-39, a polyorganosiloxane is added to a polyurethane elastic component, and a composite fiber with a thermoplastic fiber-forming polymer component is subjected to composite spinning, and then the obtained composite yarn is subjected to draw false twisting to form a two-component composite yarn. The method of dividing into is presented.

[0004]

However, the spindle method has its own limit on the number of rotations of the spindle.
Further, the bulky processed yarn must be separately manufactured by a false twisting machine, and there is a drawback that the production cost is high due to the slow production speed and the multifaceted process.

Further, in the case of the method of Japanese Patent Publication No. 56-5850, the polyurethane elastic yarn is embrittled by heat and the stretchability is significantly impaired.

Furthermore, according to the method of Japanese Patent Laid-Open No. 63-145439, it is necessary to add polyorganosiloxane to the urethane elastic yarn side. If a large amount of polyorganosiloxane is added, the heat resistance of the urethane elastic yarn becomes poor, On the contrary, if the amount is small, there is a problem that division of the two components becomes difficult, and it has not been put to practical use.

On the other hand, the method of aligning the polyurethane elastic yarn and the filament to be the covering yarn during the draw false twist is high in productivity because it can be processed at a production speed of about 100 m / min. Is difficult to uniformly coat, and when the polyurethane elastic yarn passes through the false twist heater in the stretched state, it is heat-set or partially embrittled by heat, and there is a drawback that the stretchability is deteriorated. Further, since the polyurethane elastic yarn and the bulky processed yarn are separated when passing through a guide or a tensor in the subsequent processing step, there is a drawback in that additional twisting must be performed after false twisting.
Furthermore, it is difficult to warp the polyurethane elastic yarn, and a special positive feeding device must be provided, which complicates the device and makes operability difficult. In particular, there is a problem that starting becomes extremely difficult when the delivery speed of the polyurethane elastic yarn exceeds 150 m.

[0008]

The present inventors have completed the present invention as a result of intensive studies to solve the above problems.

That is, the composite yarn of the present invention is a composite fiber composed of a water-soluble polyester (E component), a thermoplastic fiber-forming polymer (F component) and polyurethane (U component), wherein the E component is F or U. It is characterized in that it is in contact with both components at least at one or more locations in the yarn cross section and that the E component is exposed on the fiber surface.

The present invention will be described in detail below. The polyurethane as the core component constituting the present invention refers to thermoplastic polyurethane or crosslinked polyurethane. Here, the thermoplastic polyurethane is a polymer obtained by reacting a polymer diol with an organic diisocyanate and a chain extender and is a melt-spinnable polymer.

As the polymer diol, ether polyols having hydroxyl groups at both ends and having a molecular weight of 500 to 5000, such as polytetramethylene glycol and polypropylene glycol, polyhexamethylene adipate, polybutylene adipate, polycarbonate diol, polycaprolactone diol. These are glycols such as ester-based polyols, etc., alone, or mixtures thereof, and copolymerized diols.

Examples of the chain extender include 1,4-butanediol having a molecular weight of 500 or less, ethylene glycol, propylene glycol and bishydroxyethoxybenzene.

The organic diisocyanate is tolylene diisocyanate (TDI), 4,4'-diphenylmethane diisocyanate (MDI), or a non-yellowing diisocyanate such as 1,6-hexamethylene diisocyanate, and a mixture thereof.

The hardness of polyurethane polymerized from these components by a known method is preferably in the range of 75 to 98. When the hardness is less than 75, problems such as poor recovery of the obtained yarn and insufficient practical heat resistance occur, which are not preferable. On the other hand, if the hardness exceeds 98, the polyurethane itself is inferior in valency, and the recovery of the yarn cannot be expected unless the crimped structure is used, and the optimum spinning condition range of the polyurethane is extremely narrow, which is not preferable. , And more preferably in the range of 82 to 95.

Known modifiers such as titanium oxide, an ultraviolet stabilizer, an ultraviolet absorber and an antibacterial agent can be added to such polyurethane.

Further, when further heat resistance and further recoverability of the composite yarn are required, a crosslinked polyurethane obtained by reacting polyisocyanate with the above polyurethane may be selected. As this production method, the method proposed by us (Japanese Patent Publication No. 58-46573), that is, a method in which a polyisocyanate is added to and mixed with a molten thermoplastic polyurethane to complete allophanate cross-linking during or after spinning may be used.

The polyisocyanate is a compound composed of a polyol component and an isocyanate component and having two or more, preferably 2-3 isocyanate groups in the molecule. As the polyol component, in addition to the above-mentioned diol having a molecular weight of 500 to 4000 used for polyurethane synthesis, a diol and a triol are mixed to obtain an average functionality of 2
It is also possible to suitably use a synthetic polyol having a functionality of 2 to 3 or a functionality of 2 to 3. On the other hand, as the isocyanate component, the diisocyanate used during polyurethane synthesis, a trimer of an organic diisocyanate, a reaction product of trimethylolpropane and an organic diisocyanate, or an isocyanate having a functionality in the range of 2 to 3 is used. (For example, carbodiimide-modified isocyanate) or the like, or a mixture thereof can be used.

The reaction of the above components can be carried out by a known method, but it is preferable to carry out the reaction so that the isocyanate group content becomes excessive. Of course, this amount varies depending on the desired physical properties such as heat resistance and recoverability, and the polyol used.

The amount of polyisocyanate added is preferably in the range of 5 to 40% by weight based on the mixture of polyurethane used as the core component and the polyisocyanate.
The addition amount depends on the NCO group content and type of the polyisocyanate used, but if the addition amount exceeds 40%, the mixing will be non-uniform and spinning will be unstable, and the mechanical properties of the yarn will be unsatisfactory. On the contrary, if it is less than 5%, the desired heat resistance cannot be obtained, which is not preferable. Therefore, the range of 10 to 30% by weight is preferable.

In this way, a crosslinked structure mainly composed of allophanate crosslinks is formed in the polyurethane in the core component. If the crosslinked structure is mainly due to buret bond, the spinnability is extremely deteriorated, which is not preferable. That is, since the formation rate of burette crosslinks is higher than that of allophanate crosslinks, the viscosity of the system increases during spinning, and stable spinning tends to be impossible.

On the other hand, the water-soluble polyester used in the present invention has the following composition.

Aromatic dicarboxylic acid having sulfonic acid salt as an acid component and / or its ester-forming derivative (component A)
Especially preferred are those having an alkali metal sulfonate, such as 4-sulfoisophthalic acid, 5-sulfoisophthalic acid, sulfoteretetal acid, 4-sulfophthalic acid, 4-sulfonaphthalene-2,7-dicarboxylic acid,
Although an alkali metal salt such as 5- [4-sulfophenoxy] isophthalic acid or an ester-forming derivative thereof is used, 5-sulfoisophthalic acid sodium salt or an ester-forming derivative thereof is particularly preferable. From the viewpoint of water solubility and water resistance, the dicarboxylic acid having a sulfonate group and / or its ester-forming derivative is in the range of 5 to 20 mol% with respect to the total dicarboxylic acid component, particularly preferably 6 to 12 mol%. The range is good. This amount is 5 mol%
If it is less than the above range, the water solubility will be poor. On the other hand, if it exceeds 20 mol%, troubles during polymerization and poor operability during chipping will be caused, resulting in handling of the obtained polymer and thermoplasticity. It is not preferable because it has an adverse effect.

The aromatic dicarboxylic acid and / or its ester-forming derivative (component B) excluding the above-mentioned component A include terephthalic acid and / or its ester-forming derivative (component B1) and isophthalic acid and / or its ester-forming derivative (component B1). The component (B2 component) is particularly preferable from the viewpoint of availability of raw materials, industrialization and good mechanical properties, and further, this amount is preferably 55 mol% or more based on all dicarboxylic acids. If this amount is less than 55 mol%, the physical properties of the polymer obtained, particularly the thermal stability in melting and the heat resistance, are poor, and this is not preferred. Further, the molar ratio of B1 component / B2 component is preferably 2/8 to 8/2 from the viewpoint of making the polymer amorphous.

As the alicyclic dicarboxylic acid and / or its ester-forming derivative component (component C), 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 1,3
-Cyclopentanedicarboxylic acid, 4,4'-bicyclohexylcarboxylic acid and the like, or ester-forming derivatives thereof are used.

Further, examples of the aliphatic dicarboxylic acid and / or its ester-forming derivative component (D component) include adipic acid, sebacic acid, azelaic acid and the like. and,
It is preferable that the C component and the D component satisfy the relationship of 0 mol% ≦ C + 4 × D ≦ 40 mol% not only to prevent blocking of the obtained polymer but also from the viewpoint of water resistance.
This is because when the D component is, for example, 20 mol% and the C component is 0 mol%, the glass transition temperature of the obtained polymer is about room temperature, the handleability is poor, and the physical properties of the polymer are poor. ..

On the other hand, as the diol component, from the viewpoint of spinnability of the polyester copolymer, ethylene glycol is used in an amount of 50 mol% or more based on all glycol components. In addition to ethylene glycol as a glycol component, 1,4-butanediol, neopentyl glycol, other than ethylene glycol, within a range that does not adversely affect mechanical properties and heat melting stability.
You may use together 1,4-cyclohexane dimethanol, diethylene glycol, triethylene glycol, polyethylene glycol, etc.

As the method for polymerizing the copolyester used in the present invention, various ordinary methods can be used. For example, after transesterification reaction of dimethyl ester of dicarboxylic acid and glycol and letting out methanol,
Method to perform polycondensation under reduced pressure and high vacuum gradually, or method to perform esterification reaction of dicarboxylic acid and glycol and let out generated water, then gradually reduce pressure and perform polycondensation under high vacuum , Or in the case where dimethyl ester of dicarboxylic acid and dicarboxylic acid are used together as a raw material, transesterification reaction of dimethyl ester of dicarboxylic acid and glycol,
Further, there is a method in which dicarboxylic acid is added to carry out an esterification reaction and then polycondensation is carried out under high vacuum. As the transesterification catalyst, manganese acetate, calcium acetate, zinc acetate and the like can be used, and as the polycondensation catalyst, known ones such as antimony trioxide, germanium oxide, dibutyltin oxide and titanium tetrabutoxide can be used. Further, phosphorus compounds such as trimethyl phosphate and triphenyl phosphate and hindered phenol compounds such as Irganox 1010 may be used as the stabilizer. However, various conditions such as the polymerization method, the catalyst and the stabilizer are not limited to the above-mentioned examples.

The above-mentioned polyester used in the present invention is water-soluble, but the water-solubility referred to in the present invention is not strictly physicochemical, and includes those which are dissolved and / or finely dispersed in water.

Among such water-soluble polyesters, those having a glass transition temperature in the range of 35 to 80 ° C. are preferable. If the temperature is lower than 35 ° C, the handleability of the obtained composite yarn will be poor, which is not preferable. 80 on the contrary
If the temperature exceeds ° C, the solubility in water becomes insufficient, which is not preferable. Within the above range, for example, it is easily soluble in hot water at a temperature of 50 ° C. or higher, but extremely insoluble or tacky in water below this temperature, resulting in good handleability. This glass transition temperature is measured with a thermal analyzer (TAS100) manufactured by Rigaku Co., Ltd., by once raising the temperature to 180 ° C. at a rate of 10 ° C./min in a nitrogen stream, then cooling to −150 ° C. and then raising the temperature again. did.

Further, the water-soluble polyester is preferably melt-spinnable, and for example, it is desirable that the water-soluble polyester shows fluidity in the range of 180 ° C. to 300 ° C. and can be spun without foaming or decomposition. Further, additives such as an antioxidant and a slip agent may be added to the water-soluble polyester.

As the thermoplastic fiber-forming polymer, nylon 6, nylon 66, nylon 612, nylon 1
1, polyamide such as nylon 12 and copolymers containing these as the main components, or polyester such as polyethylene terephthalate, polybutylene terephthalate, polyoxyethylene benzoate and copolymers containing these as the main components, or polypropylene, polyethylene and these And a thermoplastic polymer or copolymer having a molecular weight that is melt-extrudable and has a fiber-forming property. Of these, polyamide and polyester are more preferable.

Usually, the melting temperature of the thermoplastic polyurethane elastic material is preferably 190 to 240 ° C, particularly preferably 200 to 230 ° C. Therefore, it is preferable that the melting temperature of the thermoplastic fiber-forming polymer to be simultaneously discharged is also in the range of 190 to 240 ° C. From this viewpoint, the thermoplastic fiber-forming polymer has a relatively low viscosity such as nylon 6, nylon 66, and polyethylene terephthalate, or a copolymer containing nylon 6, nylon 66, polyethylene terephthalate, polybutylene terephthalate, and polypropylene as a main component. Those having a melting point of 230 ° C. or lower, particularly 210 ° C. or lower, are preferred.

A slip agent, a conductive agent,
You may put additives, such as an antibacterial agent.

The three components of the composite yarn of the present invention have been described above. Next, these composite forms will be described. Of the water-soluble polyester (E component), the thermoplastic fiber-forming polymer (F component), and the polyurethane (U component), the E component is in contact with both the F and U components in at least one location in the fiber cross section. Things are desirable. Furthermore, it is desirable that the E component is present on all surfaces where the U and F components come into contact. This is so that the F component and the U component can be separated by water treatment in the subsequent process. A preferred example of the composite form used in the present invention is shown in FIG. An example for comparison is shown in FIG.

The polyurethane component may be partially exposed on the fiber surface, but in that case, the ratio of the cross-sectional area ratio to the entire fiber surface is preferably 30% or less. Further, it is preferably 15% or less, particularly preferably 5% or less. This is because when polyurethane is placed on the yarn surface beyond this proportion,
The degree of sticking and friction of polyurethane has an adverse effect on the operability at the time of draw false twist, and, for example, when it is formed into a knitted fabric, sliminess and dyeability are unfavorable. The area ratio of the E component in the yarn cross section is as follows:
2-30%, U component 48-90%, F component 10-4
A range of 5% is preferable.

On the other hand, the cross-sectional shape of the composite yarn may be circular or irregular. From the viewpoint of operational stability, a circular shape is preferable.

In the present invention, an example of a method for producing a composite yarn using crosslinked polyurethane will be described. A portion where a polyisocyanate is added and mixed to a portion where a thermoplastic polyurethane is melt-extruded, a water-soluble polyester, a portion where a thermoplastic fiber-forming polymer component is melt-extruded, and a composite spinning obtained in a shape as shown in FIG. It is suitable to carry out by a melt-composite spinning apparatus provided with a head portion having a spinneret. The number of F components surrounding the polyurethane is preferably 2 or more.

As a device used for adding polyisocyanate during spinning, a known device can be used. It is possible to use a kneading device having a rotating part for the portion where polyisocyanate is added and mixed to the polyurethane in a molten state, but it is more preferable to use a mixing device having a static kneading element. A known device can be used as a mixing device having a static kneading element. The shape and the number of elements of the static kneading element differ depending on the conditions of use, but it should be selected so that the thermoplastic polyurethane and the polyisocyanate are sufficiently mixed before entering the composite spinneret. It is essential and usually 20 to 90 elements are provided.

In this way, the polyurethane mixed with polyisocyanate is used as one component, and the water-soluble polyester and the thermoplastic fiber-forming polymer are melted by another two extruders and guided to a desired composite spinneret for spinning. The composite yarn of the present invention is obtained.

As the winding method, either a method using an ordinary winding machine (usually a spinning speed of 500 to 4,000 m / min), a method of drawing at the time of spinning, or a so-called spin draw method may be used. In the case of using an ordinary winding machine, a stretching step of 1.5 to 4 times is required with or without heat. This is because the strain of the polyurethane is incorporated together with the stretching of the thermoplastic fiber-forming polymer. Of these, the spin draw method is preferable.
That is, the composite yarn during spinning is 1.
This is because, if the film is stretched in the range of 3 to 6.5 times with or without heat, the handling property becomes very easy in the subsequent step, for example, during the drawing false twisting process. When performing draw false twist,
The temperature is 100 to 200 ° C., preferably 120 to 180.
It is preferable to false-twist at a magnification of 1.1 to 6 times in the range of ° C. The false twist number is preferably in the range of 10 to 2,000 T / m.

The false twisting machine may be a known device such as a conventional outdraw type draw false twisting machine, or an indrow method in the case of drawn filament or spin draw yarn. The heat treatment heater used may be either a plate type contact type or a tube type non-contact type.

As the method for treating the yarn of the present invention with water, the method of forming the yarn of the present invention into a cloth and then dissolving the water-soluble polyester component with water in the steps of scouring and dyeing may be used.

[0043]

EFFECTS OF THE INVENTION According to the present invention, it has been necessary to separately prepare a polyurethane elastic yarn and a filament made of a non-elastomer, which is a covering yarn, but it is possible to carry out spinning once, and the steps are largely omitted. can do.
Since the elongation of the composite yarn obtained by spinning can be made small, it is very easy to handle. Moreover, it is convenient because the expansion and contraction elasticity is restored by water treatment in the subsequent step.
To spin polyurethane simultaneously with water-soluble polyester and fiber-forming polymer, for example, at a high speed of 3,000 m
It can be wound at speeds such as.

Since it has excellent characteristics as described above, it can be used for various purposes. For example, when it is used for a swimsuit, a product having a shortened process and excellent operability can be obtained, and it can be suitably used for socks, innerwear, pantyhose, etc.

[0045]

EXAMPLES The present invention will now be specifically described with reference to examples, but the present invention is not limited thereto. Example 1 Thermoplastic polyurethane Polycaprolactone glycol having a molecular weight of 2,000 1,
482 parts by weight, p, p'-diphenylmethane diisocyanate 804 parts by weight, and 214 parts by weight of 1,4 butanediol as a chain extender were used for the synthesis. The relative viscosity of this polymer at a concentration of 1 g / 100 cc measured at 25 ° C. in dimethylformamide was 2.15. Polyisocyanate 850 parts by weight of polycaprolactone glycol having a molecular weight of 850, p, p'-diphenylmethane diisocyanate 5
It was reacted with 00 parts by weight to obtain a viscous compound. The NCO% of this compound was 6.2% by weight. A thermoplastic fiber-forming polymer 6 nylon having a relative viscosity of 2.0 was used. Water-soluble polyester copolymer dimethyl terephthalate 38.74 parts by weight, dimethyl isophthalate 31.95 parts by weight, 5-sulfoisophthalic acid dimethyl sodium salt 10.34 parts by weight, ethylene glycol 54.48 parts by weight, calcium acetate monohydrate Salt 0.07
After 3 parts by weight and 0.024 part by weight of manganese acetate tetrahydrate were subjected to transesterification under a nitrogen stream at 170 to 220 ° C. while distilling off methanol, 0.5 part by weight of trimethyl phosphate and polycondensation catalyst. As antimony trioxide 0.
04 parts by weight and 1,4-cyclohexanedicarboxylic acid 1
Esterification was carried out by adding 7.17 parts by weight and distilling off a theoretical amount of water at a reaction temperature of 220 to 235 ° C. After that, the pressure inside the reaction system is further reduced and the temperature is raised to 280 ° C and 0.2 mm finally.
Polycondensation was carried out at Hg for 2 hours. Then, polymerization was performed in the same manner with the composition ratio shown in Table 1.

The obtained polymer was evaluated by the following methods. Glass transition temperature: Thermal analysis device (TAS1) manufactured by Rigaku Co., Ltd.
00) at a rate of 10 ° C / min in a nitrogen stream once.
The temperature was raised to 80 ° C., then cooled to −150 ° C., and again raised to measure. Water solubility: 425 g of water was added to 75 g of the polyester copolymer, and the mixture was stirred at 95 ° C. for 3 hours for evaluation.

Spinning of the water-soluble polyester alone was carried out. The nozzle temperature was 230 ° C., the nozzle diameter was 0.5 mm, the winding speed was 500 m / min, the oil agent was a dimethyl silicon-based oil agent, and a 40-denier 1-filament thread was collected. The results are shown in Table 1. From Table 1,
The polymer from Comparative Example 1-1 was poor in handleability when dried, and the yarn obtained from this polymer had a large degree of sticking. Therefore, the tenacity and elongation of this yarn was not measured. Comparative Example 1-2
Is 5-sulfoisophthalic acid dimethyl sodium salt 5
It was less than mol% and the polymer was insoluble in water.
The yarns from Comparative Examples 1-3 were very brittle and had poor handleability. In Comparative Example 1-4, since the diol component was 100% diethylene glycol, the glass transition temperature was close to room temperature. Further, since the drying was very difficult and the handleability was poor, spinning was not performed for this system.

Example 2 Next, an example of forming a composite yarn will be described. The thermoplastic polyurethane was melted by an extruder, 15% by weight of the polyisocyanate was added in the middle of the flow of the melt, and they were sufficiently kneaded by a 35-element static mixer (Kenix). On the other hand, Example 1
-1 water-soluble polyester is melted by another extruder,
Further, the above nylon 6 is melted by another extruder to prepare polyurethane (U) component 60, water-soluble polyester (E) 5,
Nylon (F) 35% by volume (Example 2-1), 4 for each
It was weighed so as to be 8, 10, 42% by volume (Example 2-2) and led to a composite die having a shape shown in (b) of FIG. The nozzle temperature was 235 ° C. For winding, the first godet roller of the winding machine is 1,000 m by the spin draw method.
The second drawing godet roller (draw roller) was fixed at 1 / min, the speed was doubled to the speed of the first godet roller, and the heater temperature of the roller was set to 100 ° C. to obtain two filaments having a fineness of 70d.

On the other hand, the ratio of U / E / F is 10% / 5% /
It was made to be 85% and spun in the same manner as in Example (Comparative Example 2-
1). Further, the spinning was performed in the same manner as in Example 2-1 except that the composite form (Comparative Example 2-2) shown in FIG. 2 was used. In addition, an attempt was made to spin a polyurethane elastic yarn of 70d / 2 filament under similar winding conditions, but the yarn could not be collected by such a winding method (Comparative Example 2-3). In the above spinning, two types of oil agents, dimethyl silicone and emulsion, were used.

The obtained composite yarn was false twisted in the S and Z directions under the conditions of a draw ratio of 1.5, a false twist temperature of 180 ° C. and a false twist number of 700 T / m. Then, using only these false-twisted yarns, panty hose was made by a four-knitting machine and dyed with an acid dye to a skin color under conditions of 100 ° C. × 30 minutes. Further 110
The wet heat treatment was performed at 15 ° C. for 15 seconds, and the stretch back property was measured. Here, the stretch-back property means that the calf part of the stocking is 100% in the direction perpendicular to the length of the stocking.
The elongation recovery is repeated 5 times, and the ratio of the 80% elongation stress in the final elongation and the 80% recovery stress in the final recovery is shown.
The larger this value, the better the fit. Stretch back property = (80% elongation recovery stress / 80% elongation stress) × 100 These results are shown in Table 2.

[0051]

[Table 2]

From Table 2, it can be seen that the operability is poor when the proportion of polyurethane in the fiber cross section is small as in Comparative Example 2-1 and when the composite form is as in Comparative Example 2-2. The strength of these yarns is 0.4,
It was as low as 0.5 g / d. In the yarn of this example in the pantyhose, polyurethane and nylon were completely separated.
Further, the pantyhose of this example was finished to be thinner and lighter than the conventional one made of covering yarn.

[0053]

[Brief description of drawings]

FIG. 1 is a fiber cross-sectional view showing a composite form suitable for a composite yarn of the present invention.

FIG. 2 is a fiber cross-sectional view showing an example of a composite form other than the present invention.

[Table 1]

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location D01F 8/14 Z 7199-3B 8/16 7199-3B D02G 1/02 Z 3/32 D02J 1 / 22 N D04B 1/18

Claims (3)

[Claims] 1. A composite fiber comprising a water-soluble polyester (E component), a thermoplastic fiber-forming polymer (F component) and polyurethane (U component), wherein the E component is F or U.
A composite yarn characterized by being in contact with both components at least at one or more locations in the yarn cross section. 2. The water-soluble polyester comprises 5 to 20 mol% of an aromatic dicarboxylic acid having a sulfonate and / or its ester-forming derivative (component A) as an acidic component, and the aromatic dicarboxylic acid excluding the component A. 55 mol% or more of an ester-forming derivative (component B) thereof, and an alicyclic dicarboxylic acid and / or its ester-forming derivative (component C) and an aliphatic dicarboxylic acid and / or its ester-forming derivative (component D) ) And the C component and the D component satisfy the relationship of 0 mol% ≦ C + 4 × D ≦ 40 mol%, while the glycol component is 50 mol% or more of ethylene glycol. Composite yarn. 3. The composite yarn according to claim 1, wherein the glass transition temperature of the water-soluble polyester is 35 ° C. to 80 ° C.