阅读说明：本技术 用于热熔接纤维的聚酯组合物及包括其的热熔接复合纤维 (Polyester composition for heat-fusible fiber and heat-fusible composite fiber comprising same ) 是由 崔重铉 金棹炫 李主铉 于 2019-04-26 设计创作，主要内容包括：本发明涉及一种用于热熔接纤维的聚酯组合物及包括其的热熔接复合纤维,更具体而言,涉及在粘合时柔韧,可以呈现柔软触感且致密度较低的用于热熔接纤维的聚酯组合物以及由于包含根据本发明的用于热熔接纤维的聚酯组合物而在低温和低压条件下染色时的得色率优异的热熔接复合纤维。(The present invention relates to a polyester composition for heat-fusible fibers and a heat-fusible composite fiber including the same, and more particularly, to a polyester composition for heat-fusible fibers which is flexible at the time of bonding, can exhibit a soft touch and is low in density, and a heat-fusible composite fiber excellent in color yield when dyed under low temperature and low pressure conditions due to the inclusion of the polyester composition for heat-fusible fibers according to the present invention.)

1. A polyester composition for heat-fusion bonding of fibers, characterized by comprising a copolyester obtained by polycondensing an esterified compound obtained by reacting an acid component containing terephthalic acid with a glycol component containing ethylene glycol and 2-methyl-1, 3-propanediol and a polyalkylene glycol.

2. The polyester composition for heat-fusible fiber as claimed in claim 1, wherein the diol component substantially does not include diethylene glycol.

3. The polyester composition for heat-fusion bonding of fibers according to claim 1, wherein the content of the polyalkylene glycol is 1 to 10% by weight relative to the weight of the esterified compound.

4. The polyester composition for heat-fusion bonding of fibers according to claim 1, wherein the polyalkylene glycol is polyethylene glycol.

5. The polyester composition for heat-fusion splicing fibers according to claim 4, wherein the polyethylene glycol has a weight average molecular weight of 400 to 12000.

6. The polyester composition for heat-fusion bonding of fibers according to claim 4, wherein the polyethylene glycol has a weight average molecular weight of 400 to 6000.

7. The polyester composition for heat-fusion splicing fibers as claimed in claim 1, wherein said acid component and said glycol component are contained in said esterification compound in a molar ratio of 1:1 to 1: 2.

8. The polyester composition for heat-fusion fibers according to claim 1, wherein the 2-methyl-1, 3-propanediol is included in the diol component at 25 to 40 mol%.

9. The polyester composition for heat-fusion fibers according to claim 8, wherein the 2-methyl-1, 3-propanediol is included in the diol component at 29 to 40 mol%.

10. The polyester composition for heat-fusion bonding of fibers according to claim 1, wherein the acid component further comprises isophthalic acid, and the isophthalic acid is included in the acid component in an amount of 1 to 15 mol%.

11. The polyester composition for heat-fusion bonding of fibers according to claim 1, wherein the copolyester is obtained by polycondensing an esterified compound obtained by reacting an acid component as terephthalic acid with a glycol component comprising 60 to 71 mol% of ethylene glycol and 29 to 40 mol% of 2-methyl-1, 3-propanediol in a molar ratio of 1:1 to 1:2 and polyethylene glycol in an amount of 1 to 10 wt% based on the weight of the esterified compound, and polyethylene glycol having a weight average molecular weight of 400 to 6000.

12. A heat-fusible composite fiber, comprising:

a core portion containing a polyester-based component; and

a sheath part comprising the polyester composition for heat-fusion bonding of fibers of claim 1 surrounding the above core part.

13. The thermally fused conjugate fiber of claim 12, wherein the conjugate fiber is obtained by fusing a polyethylene terephthalate staple fiber in a ratio of 1:1 and a test piece having a width, a length and a thickness of 100mm, 20mm and 10mm, respectively, which is obtained by improving the above components and then subjecting the mixture to a heat treatment at 140 ℃, the adhesive strength obtained by the KS M ISO36 method using a universal tester was 100N or more in adhesive strength.

14. The thermally welded conjugate fiber according to claim 12, wherein the fiber is obtained by mixing a dye solution containing 2 wt% of a dye, i.e., c.i Basic Blue 54, at a temperature of 120 ℃ under normal pressure, in a ratio of 1: when the composite fiber is dyed for 40 minutes at a bath ratio of 50, the K/S value, which is the color yield of the composite fiber according to CIE 1976, is 14 or more.

15. The thermally fused conjugate fiber of claim 12, wherein the polyester-based component comprises at least one selected from the group consisting of polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, and polybutylene adipate terephthalate.

16. A decorative fiber comprising the heat-fusible composite fiber according to claim 12.

17. The decorative fiber according to claim 16, wherein the decorative fiber is suitable for use in one selected from the group consisting of vehicle seats, bedding, roller blinds, curtains and ornaments.

Technical Field

The present invention relates to a polyester composition for heat-fusible fibers and a heat-fusible composite fiber including the same, and more particularly, to a polyester composition for heat-fusible fibers which is flexible at the time of bonding, can exhibit a soft touch and is low in density, and a heat-fusible composite fiber excellent in color yield when dyed under low temperature and low pressure conditions due to the inclusion of the polyester composition for heat-fusible fibers according to the present invention.

Background

In general, polyester is a general term for a polymer compound having an ester bond (-COO) in a molecule, and examples thereof include thermoplastic polyester resins represented by unsaturated polyester resins, alkyd resins, and polyethylene terephthalate (PET).

Such polyester fibers have high strength and chemical resistance, have excellent heat resistance due to a melting point in the range of 250 ℃ to 255 ℃, and have the advantage of elasticity in elongation and bending, and therefore are used not only for garments such as gentleman clothes and shirts but also for industrial materials, and the like, and are widely used.

However, the above polyester has a high melting point, and therefore, when a fiber structure is hardened, a binder containing formalin (formaldehyde aqueous solution) or an organic solvent, a hard resin (phenol resin, melanin resin, urea resin) is generally used. The adhesive containing such an organic solvent does not penetrate into the inside of the cloth, and therefore, the adhesiveness is low and the touch at the time of finishing is rough. In addition, the method has the environmental problems of strong volatility, harm to human bodies by most substances, discharge of toxic gases and the like.

In addition, although a conventional polyester-based conjugate fiber composed of a sheath portion and a core portion uses a low-melting polyester for the sheath portion, it is difficult to practically apply the fiber to a decorative product because softness is remarkably low and touch is rough at the time of bonding, and there is a problem that a high-temperature and high-pressure environment is required at the time of dyeing the conjugate fiber.

Disclosure of Invention

Technical problem

The present invention has been made in view of the above problems, and it is an object of the present invention to provide a polyester composition for heat-fusion bonded fibers which is flexible at the time of bonding, can exhibit a soft touch and is low in density, and a heat-fusion bonded composite fiber excellent in color yield when dyed under low temperature and low pressure conditions due to the inclusion of the polyester composition for heat-fusion bonded fibers according to the present invention.

And, another object of the present invention is to provide a decorative fiber including the heat-fusion bonded composite fiber according to the present invention.

Means for solving the problems

In order to solve the above problems, the present invention provides a polyester composition for heat-fusion bonding fibers comprising a copolyester obtained by polycondensing an esterified compound obtained by reacting an acid component containing terephthalic acid with a glycol component containing ethylene glycol and 2-methyl-1, 3-propanediol and a polyalkylene glycol.

According to an embodiment of the present invention, the diol component may substantially not include diethylene glycol.

Also, according to an embodiment of the present invention, the content of the polyalkylene glycol may be 1 to 10% by weight with respect to the weight of the esterified compound.

Furthermore, according to an embodiment of the present invention, the polyalkylene glycol may be polyethylene glycol.

In addition, according to an embodiment of the present invention, the weight average molecular weight of the polyethylene glycol may be 400 to 12000.

In addition, according to an embodiment of the present invention, the weight average molecular weight of the polyethylene glycol may be 400 to 6000.

Also, according to an embodiment of the present invention, the acid component and the glycol component may be included in the esterified compound in a molar ratio of 1:1 to 1: 2.

Also, according to an embodiment of the present invention, the 2-methyl-1, 3-propanediol may be included in the diol component at 25 mol% to 40 mol%.

Also, according to an embodiment of the present invention, the 2-methyl-1, 3-propanediol may be included in the diol component at 29 mol% to 40 mol%.

Further, according to an embodiment of the present invention, the acid component may further include isophthalic acid, and the isophthalic acid may be included in the acid component in an amount of 1 mol% to 15 mol%.

Also, according to an embodiment of the present invention, the copolyester may be obtained by polycondensing an esterified compound obtained by reacting an acid component, which is terephthalic acid, with a glycol component including 60 to 71 mol% of ethylene glycol and 29 to 40 mol% of 2-methyl-1, 3-propanediol in a molar ratio of 1:1 to 1:2, and polyethylene glycol having a weight average molecular weight of 400 to 6000 in an amount of 1 to 10 wt% with respect to the weight of the esterified compound.

Also, the present invention provides a heat-fusible composite fiber including: a core portion containing a polyester-based component; and a sheath part including the polyester composition for heat-fusion bonding of fibers according to the present invention surrounding the above core part.

According to an embodiment of the present invention, the composite fiber is obtained by mixing the polyethylene terephthalate staple fiber with a fiber mixture of 1: when the fiber mixture is mixed at a weight ratio of 1 and test pieces having a width, a length and a thickness of 100mm, 20mm and 10mm, respectively, are obtained by heat treatment at a temperature of 140 ℃ after the improvement, the adhesive strength can be 100N or more when measured by a Universal Testing Machine (UTM) according to KS M ISO 36.

Also, according to an embodiment of the present invention, in a dye solution containing 2 wt% of a dye (c.i Basic Blue 54) based on the weight of the composite fiber, the dye solution is mixed at a temperature of 120 ℃ and under normal pressure conditions such that 1: when the composite fiber is dyed for 40 minutes at a bath ratio of 50, the color yield (K/S value) of the composite fiber according to CIE 1976 standard may be 14 or more.

In one embodiment of the present invention, the polyester component may include at least one selected from the group consisting of polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, and polybutylene adipate terephthalate.

Also, the present invention provides a decorative fiber including the heat-fusion bonded composite fiber according to the present invention.

According to an embodiment of the present invention, the decorative fiber may be applied to one selected from a vehicle seat, bedding, a roll screen, a curtain, and a decorative article.

ADVANTAGEOUS EFFECTS OF INVENTION

The polyester composition for heat-fusible fibers according to the present invention is flexible at the time of bonding, can exhibit a soft touch and is low in density, and thus can realize heat-fusible composite fibers excellent in color yield when dyed under low temperature and low pressure conditions. The heat-fusible composite fiber according to the present invention is included in a decorative fiber, and thus can be widely used for vehicle seats, bedding, roller blinds, curtains, ornaments, and the like.

Drawings

Fig. 1 is a schematic cross-sectional view of a thermally welded composite fiber according to an embodiment of the present invention.

Detailed Description

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings so that those skilled in the art can easily implement the present invention. The present invention can be realized in various different embodiments, and is not limited to the embodiments described in the present specification.

The polyester composition for heat-fusion bonding fibers of the present invention will be explained.

The polyester composition for heat-fusion bonding of fibers of the present invention comprises a copolyester obtained by polycondensing an esterified compound obtained by reacting an acid component containing terephthalic acid with a glycol component containing ethylene glycol and 2-methyl-1, 3-propanediol and polyalkylene glycol.

The esterified compound can exhibit thermal adhesion characteristics at low temperatures due to the 2-methyl-1, 3-propanediol contained in the diol component, and the copolyester of the present invention has excellent adhesion strength at the time of adhesion, and also has soft touch and flexibility by polycondensing the esterified compound having low-temperature thermal adhesion characteristics and the polyalkylene glycol having a flexible chain structure that can reduce density, and thus is excellent in spinning workability and also excellent in dyeability even under low-temperature and low-pressure environmental conditions.

The above acid component may further contain isophthalic acid contained in the above acid component in an amount of 1 to 15 mol%, so that the glass transition temperature of the copolyester is lowered and the adhesive strength and soft touch at the time of adhesion may be further excellent.

When the isophthalic acid is contained in an amount of less than 1 mol% in the acid component, the effects of lowering the glass transition temperature of the copolyester, improving the adhesive strength at the time of bonding, and further improving the soft touch may not be exhibited. When the isophthalic acid is contained in an amount of more than 15 mol% in the acid component, the soft touch is reduced, and a large amount of cyclic compounds are generated as by-products by the use of isophthalic acid, which may cause yarn breakage during spinning.

Preferably, 2-methyl-1, 3-propanediol may be contained in the above diol component at 25 mol% to 40 mol%, more preferably, may be contained in the above diol component at 29 mol% to 40 mol%.

When the glycol component contains less than 25 mol% of the 2-methyl-1, 3-propanediol, it is difficult to use the copolyester for heat-fusion of fibers because the bonding temperature of the copolyester becomes high, and when the glycol component contains more than 40 mol% of the 2-methyl-1, 3-propanediol, the melting point increases with the increase in crystallinity of the copolyester, and the like, and it may be difficult to achieve the object of the present invention.

Further, when the 2-methyl-1, 3-propanediol is contained in the diol component in an amount of 29 to 40 mol%, a desired melting point lowering effect can be exhibited even when the 2-methyl-1, 3-propanediol is used alone as the diol component, and when the diol component is used in combination with isophthalic acid and polyethylene glycol, not only the melting point can be lowered more effectively, but also excellent adhesive strength can be exhibited.

When the diol component contains diethylene glycol in addition to the naturally occurring amount, there is a problem that the glass transition temperature is sharply decreased, the heat resistance is decreased, the secular change and the storage stability are likely to be decreased, and the melt viscosity of spinning is decreased to cause frequent yarn breakage, thereby significantly decreasing the spinnability.

In the polyester composition for heat-fusion bonding of fibers according to an embodiment of the present invention, the glycol component substantially does not contain diethylene glycol, and thus it is possible to prevent or minimize problems such as fiber breakage, reduction in section uniformity, reduction in dyeing uniformity, and rapid reduction in heat resistance (glass transition temperature) during spinning processing.

However, the diethylene glycol may occur naturally during the esterification reaction.

The acid component and the diol component are prepared by mixing the following components in a ratio of 1:1 to 1:2, when the above molar ratio is less than 1:1, the acidity becomes too high at the time of polymerization, and side reactions may be promoted, and when the above molar ratio is more than 1:2, the degree of polymerization may not be high.

The polymerization of the acid component and the diol component described above may be carried out under the conditions used in the esterification polymerization reaction conventionally used in the art, and may be carried out by stirring at a temperature of 200 ℃ to 260 ℃ for 150 minutes to 240 minutes at a speed of 40rpm to 80rpm, as an example, but the present invention is not limited thereto.

Secondly, the copolyester of the present invention can be prepared by polycondensing the above esterified compound with polyalkylene glycol.

Preferably, the polyalkylene glycol may be polyethylene glycol.

More preferably, the above polyethylene glycol may have a weight average molecular weight of 400 to 12000, and when the weight average molecular weight of the above polyethylene glycol is less than 400, it is difficult to exhibit desired soft touch and migration property effects, and when the weight average molecular weight of the above polyethylene glycol is more than 12000, polymerization reactivity is reduced, and thermal stability may be deteriorated due to reduction in heat resistance of the formed polymer. Most preferably, the above polyethylene glycol may have a weight average molecular weight of 400 to 6000, and thus, not only may exhibit desired soft touch and migration properties, but also may be more excellent in the effect of preventing or minimizing the reduction in heat resistance.

The content of the above polyalkylene glycol may be 1 to 10% by weight relative to the weight of the above esterified compound. When the content of the polyalkylene glycol is less than 1% by weight with respect to the weight of the esterified compound, it is difficult to exhibit desired soft touch and migration dyeing effects and also to reduce the dyeing property of the copolyester under low temperature and low pressure environments, and when the content of the polyalkylene glycol is more than 10% by weight with respect to the weight of the esterified compound, polymerization reactivity is reduced, and heat stability is deteriorated due to reduction of heat resistance of the formed polymer, spinning workability is reduced, and the like, and it is difficult to achieve the object of the present invention.

And, more preferably, the content of the above polyalkylene glycol may be 1 to 5% by weight with respect to the weight of the above esterified compound, so that not only the polycondensation reactivity is further stably maintained, but also the heat resistance of the copolyester produced can be ensured at a more stable level.

As described above, the copolyester of the present invention can have excellent adhesive strength at the time of bonding and also has soft touch and flexibility by polycondensing the esterified compound having low-temperature thermal bonding characteristics and the polyolefin-based diol of a flexible chain structure capable of reducing density, by virtue of 2-methyl-1, 3-propanediol contained in the diol component, and thus can exhibit thermal bonding characteristics at low temperature, and is excellent in spinning workability even under low-temperature and low-pressure environmental conditions, and when the copolyester is obtained by polycondensing the esterified compound obtained by reacting an acid component as terephthalic acid with a diol component comprising 60 to 71 mol% of ethylene glycol and 29 to 40 mol% of 2-methyl-1, 3-propanediol in a molar ratio of 1:1 to 1:2, and polyethylene glycol, the content of the polyethylene glycol is 1 to 10% by weight with respect to the weight of the esterified compound, and the weight average molecular weight of the polyethylene glycol is 400 to 6000, so that a soft touch, a dyeing property under low temperature and low pressure environments, and an adhesive strength at the time of bonding may be more excellent. In particular, as for thermal bonding, there is an advantage of exhibiting excellent bonding strength in a wide temperature range from low temperature to high temperature.

Next, the heat-fusion bonded composite fiber of the present invention will be described.

The thermal bonding composite fiber 10 of the present invention includes: a core 11 containing a polyester-based component; and a sheath part 12 comprising the polyester composition for heat-fusion fibers according to the present invention surrounding the above core part 11.

The polyester-based component contained in the core 11 may include at least one selected from the group consisting of polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, and polybutylene adipate terephthalate.

In order to minimize the problem of the decrease in spinning workability, the fineness of the above composite fiber 10 may preferably be 1De to 15 De. Since the above polyester composition for heat-fusion bonding of fibers has the same constitution as described above, a detailed description thereof will be omitted.

The composite fiber may be prepared by a composite spinning method conventionally used in the art, and a melt composite spinning method may be used as an example, but the present invention is not limited thereto.

Also, the heat-fusible composite fiber according to the present invention includes a polyester composition for heat-fusible fibers in a sheath portion, which has excellent adhesive strength at the time of bonding, also has soft touch and flexibility, is excellent in spinning workability, and has excellent dyeability even under low-temperature and low-pressure environmental conditions, and thus, when the adhesive strength is measured according to the KS M ISO36 method, may have excellent adhesive strength of 100N or more, when a dye solution containing 2 wt% of a dye (c.i Basic Blue 54) based on the weight of the above composite fiber, is mixed at a temperature of 120 ℃ and under normal pressure conditions of 1: when the dyeing is carried out for 40 minutes at a bath ratio of 50, the excellent dyeing property can be obtained with a color yield (K/S value) of 14 or more according to the CIE 1976 standard.

Next, a decorative fiber including the heat-fusion bonded composite fiber according to the present invention will be described. Since the decoration fiber includes the heat-welded composite fiber according to the present invention, dyeing can be performed even in a low-temperature and low-pressure environment, so that dyeing process costs can be significantly reduced, and excellent durability and soft touch of a decoration product can be ensured due to excellent adhesive strength. Therefore, the decorative fiber can be suitably used for one selected from vehicle seats, bedding, roller blinds, curtains, and ornaments.

Mode for the invention

The present invention is further specifically illustrated by the following examples, which are not intended to limit the scope of the present invention but are to be construed as aiding in the understanding of the present invention.

< example 1>

After Terephthalic acid (TPA), Ethylene Glycol (EG), and 2-methyl-1, 3-propanediol (MPO) were charged in an ester reaction tank, a reaction was performed at a temperature of 250 ℃ by a conventional method to prepare an esterified compound. In preparing the esterified compound, the reaction is carried out in a ratio of 1: an acid component and a glycol component were mixed at a molar ratio of 1.5, and Ethylene Glycol (EG) was contained at 65 mol% and 2-methyl-1, 3-propanediol (MPO) was contained at 35 mol%.

After 2% by weight of polyethylene glycol (weight average molecular weight: 1000) was charged relative to the weight of the prepared esterified compound, the pressure was slowly reduced to a final reduced pressure of 1.0Torr, and the temperature was raised to 285 ℃ and polycondensation was carried out to obtain a copolyester.

In order to use the prepared low-melting copolyester as a sheath part and polyethylene terephthalate as a core part, spinning was carried out at a spinning temperature of 275 ℃ and a spinning speed of 500mpm using a sheath/core tube, and a polyester composite fiber (fineness: 4de, length: 51mm) was prepared by post-treatment processing.

< examples 2 to 14>

A composite fiber was produced in the same manner as in example 1, except that at least one of the acid component, the diol component, their contents, the content of polyethylene glycol and the weight average molecular weight thereof contained in the esterified compound was changed as shown in table 1 below.

< comparative examples 1 to 4>

A composite fiber was produced in the same manner as in example 1, except that at least one of the acid component, the diol component, their contents, the content of polyethylene glycol and the weight average molecular weight thereof contained in the esterified compound was changed as shown in table 1 below.

< Experimental example 1>

The glass transition temperature of the copolyesters prepared in examples and comparative examples and the viscosity of the polyester compositions were measured, and the adhesive strength, color yield, soft touch and spinning workability of the composite fibers prepared in examples and comparative examples were evaluated, and the results thereof are shown in the following table 1.

(1) Glass transition temperature measurement

The glass transition temperatures (T.sub.t) of the copolyesters prepared in the examples and comparative examples were determined using Differential Scanning Calorimetry (DSC)_g) The results are shown in table 1 below. When the glass transition temperature was measured, the temperature increase rate was set to 20 ℃/min.

(2) Viscosity measurement

The copolyesters prepared in examples and comparative examples were added to o-chlorophenol (Ortho-Chloro Phenol) at a concentration of 0.2g/25ml, and then melted at a temperature of 110 ℃ for 30 minutes. The molten solution was kept at 25 ℃ for 30 minutes, and then the viscosity was measured using an automatic viscosity measuring apparatus connected to a Canon (CANON) viscometer.

(3) Evaluation of adhesive Strength

In the case of using a carding machine (carding machine) to combine the polyester composite fibers prepared in examples and comparative examples with ordinary polyethylene terephthalate staple fibers, the ratio of 5: 5 ofAfter proportional mixing and modification, heat treatment was carried out at 140 ℃ with a tenter (tenter) to obtain a basis weight of 35g/m²The nonwoven fabric of (1) was realized as test pieces having a width, a length and a thickness of 100mm, 20mm and 10mm, respectively, and the adhesive strength was measured by a Universal Testing Machine (UTM) according to KS M ISO36 method.

(4) Evaluation of color yield

Evaluation of color yield for a dye solution containing 2 wt% of a dye (c.i Basic Blue 54) based on the weight of the conjugate fiber, the dye solution was measured at a temperature of 120 ℃ under normal pressure conditions of 1: after dyeing the conjugate fiber at a bath ratio of 50 for 40 minutes, the spectral reflectance of the visible region (interval of 360nm to 740nm, 10 nm) of the dyed conjugate fiber was measured by a color measurement system of Kurabao (KURABO) corporation, and the total K/S value as an index of the dyeing amount according to the CIE 1976 standard was calculated to evaluate the color yield of the dye.

(5) Evaluation of Soft touch feeling

The soft touch of the conjugate fiber was evaluated by a sensory test method using a panel of 10 experts in the same industry, and when 8 or more of the fibers were judged to be soft in the sensory test results, the fibers were distinguished as excellent (. circleincircle.), 6 to 7 of the fibers were good (. largecircle.), 4 to 5 of the fibers were normal (. DELTA.), and less than 4 of the fibers were poor (. largecircle.).

(6) Evaluation of spinning workability

The spinning workability of the conjugate fiber was evaluated by a sensory test method using a panel of 10 same-industry experts based on whether or not the yarn was broken and the uniformity of the cross section during the spinning process, and in the sensory test results, when 8 or more of the fibers were judged to be excellent in spinning workability, the fibers were excellent (. circleincircle.), good (. largecircle.) in 6 to 7, ordinary (. DELTA.) in 4 to 5, and poor (. times.) in less than 4.

TABLE 1

Referring to table 1 above, it was confirmed that example 4, which contained 3 mol% of Isophthalic Acid (IPA) in the esterification reaction, was superior in adhesive strength to example 3, which did not contain Isophthalic Acid (IPA). In addition, it was confirmed that comparative example 4 containing Diethylene glycol (DEG) significantly reduced spinning workability in composite fiber spinning during the esterification reaction.

On the other hand, it was confirmed that comparative example 2 containing no Polyethylene glycol (PEG) in the polycondensation reaction was significantly low in adhesive strength and color yield, and did not realize an excellent soft touch. On the contrary, it was confirmed that example 6 containing 9 wt% of polyethylene glycol (PEG) in the polycondensation reaction was excellent in all of the adhesive strength, the color yield, the soft touch and the spinning workability, but comparative example 3 containing 13 wt% of polyethylene glycol (PEG) had a problem that the polymerization itself was difficult.

Further, it was confirmed that example 2 containing polyethylene glycol (PEG) having a weight average molecular weight of 200 was superior in adhesive strength and color yield and also superior in soft touch in the polycondensation reaction to example 1 having a weight average molecular weight of 500. On the other hand, example 10 containing polyethylene glycol (PEG) having a weight average molecular weight of 13500 has a problem that polymerization itself is difficult, and example 9 containing polyethylene glycol (PEG) having a weight average molecular weight of 11200 is remarkably excellent in adhesive strength, color yield, and soft touch, but spinning workability is a common level. On the other hand, it was confirmed that example 8 containing polyethylene glycol (PEG) having a weight average molecular weight of 6600 was excellent not only in adhesive strength, color yield and soft touch but also in spinning workability.

Further, example 11 containing 22 mol% of 2-methyl-1, 3-propanediol (MPO) was excellent in color yield, soft touch and spinning workability during the esterification reaction, but had a problem of relatively low adhesive strength. On the other hand, it was confirmed that example 12 containing 27 mol% of the above-mentioned 2-methyl-1, 3-propanediol (MPO) had a significant increase in adhesive strength as compared with example 11. Further, it was confirmed that example 13 containing 38 mol% of 2-methyl-1, 3-propanediol (MPO) had significantly higher adhesive strength and more excellent color yield and spinning workability, compared to example 14 containing 43 mol% of the above 2-methyl-1, 3-propanediol (MPO).

While one embodiment of the present invention has been described above, the gist of the present invention is not limited to the embodiment proposed in the present specification, and those skilled in the art who understand the idea of the present invention can easily propose other embodiments by adding, modifying, deleting, adding, etc. components within the same gist, and these embodiments fall within the gist of the present invention.