Thermoplastic Polyurethane Yarn And Fabric Made Therefrom

Abstract

Disclosed is a thermoplastic polyurethane yarn and a fabric made from the thermoplastic polyurethane yarn that uses succinate as a polyol in a thermoplastic polyurethane composition comprises of isocyanate, glycol and polyol, and further includes nano-silica having a particle size of 100 nm or less added in the polymerization of the composition, thereby increasing the crystallization rate during the cooling and drawing processes to enable a continuous spinning of yarns without yarn breaking and also realizing a continuous spinning of low-hardness (Shore A type) thermoplastic polyurethane yarns with great stretch and recovery.

Claims

1. A thermoplastic polyurethane yarn, which comprises a thermoplastic polyurethane composition comprising polyol, isocyanate, and glycol, the thermoplastic polyurethane composition comprising nano-silica having a particle size of 100 nm or less, the polyol comprising succinate.

2. The thermoplastic polyurethane yarn as claimed in claim 1, wherein the polyol further comprises adipate.

3. The thermoplastic polyurethane yarn as claimed in claim 1, wherein the thermoplastic polyurethane is a low-hardness (Shore A type) thermoplastic polyurethane.

4. The thermoplastic polyurethane yarn as claimed in claim 1, wherein the content of succinate is 5 to 30% when the thermoplastic polyurethane has a hardness of 75D.

5. The thermoplastic polyurethane yarn as claimed in claim 1, wherein the content of succinate is 5 to 40% when the thermoplastic polyurethane has a hardness of 60D.

6. The thermoplastic polyurethane yarn as claimed in claim 1, wherein the content of succinate is 5 to 45% when the thermoplastic polyurethane has a hardness of 98A.

7. The thermoplastic polyurethane yarn as claimed in claim 1, wherein the content of succinate is 10 to 55% when the thermoplastic polyurethane has a hardness of 90A.

8. The thermoplastic polyurethane yarn as claimed in claim 1, wherein the content of succinate is 20 to 75% when the thermoplastic polyurethane has a hardness of 70A.

9. The thermoplastic polyurethane yarn as claimed in claim 1, wherein a single filament of fiber is 50 denier or less when the thermoplastic polyurethane yarn is a multifilament yarn, a single filament of fiber is 50 to 350 denier when the thermoplastic polyurethane yarn is a monofilament yarn.

10. A fabric made from the thermoplastic polyurethane yarn as claimed in claim 1.

11. The thermoplastic polyurethane yarn as claimed in claim 2, wherein the content of succinate is 5 to 30% when the thermoplastic polyurethane has a hardness of 75D.

12. The thermoplastic polyurethane yarn as claimed in claim 2, wherein the content of succinate is 5 to 40% when the thermoplastic polyurethane has a hardness of 60D.

13. The thermoplastic polyurethane yarn as claimed in claim 2, wherein the content of succinate is 5 to 45% when the thermoplastic polyurethane has a hardness of 98A.

14. The thermoplastic polyurethane yarn as claimed in claim 2, wherein the content of succinate is 10 to 55% when the thermoplastic polyurethane has a hardness of 90A.

15. The thermoplastic polyurethane yarn as claimed in claim 2, wherein the content of succinate is 20 to 75% when the thermoplastic polyurethane has a hardness of 70A.

16. The thermoplastic polyurethane yarn as claimed in claim 2, wherein a single filament of fiber is 50 denier or less when the thermoplastic polyurethane yarn is a multifilament yarn, a single filament of fiber is 50 to 350 denier when the thermoplastic polyurethane yarn is a monofilament yarn.

17. The thermoplastic polyurethane yarn as claimed in claim 3, wherein a single filament of fiber is 50 denier or less when the thermoplastic polyurethane yarn is a multifilament yarn, a single filament of fiber is 50 to 350 denier when the thermoplastic polyurethane yarn is a monofilament yarn.

18. A fabric made from the thermoplastic polyurethane yarn as claimed in claim 2.

19. A fabric made from the thermoplastic polyurethane yarn as claimed in 3.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0042] FIG. 1 is a graph showing recrystallization when the thermoplastic polyurethane having a hardness of 90A according to the present invention is consistently cooled down.

[0043] FIG. 2 is a graph showing the rate of crystallization as a function of time when the thermoplastic polyurethane having a hardness of 90A according to the present invention is abruptly cooled down to a specific temperature and maintained at the temperature.

[0044] FIG. 3 is a graph showing recrystallization when the thermoplastic polyurethane having a hardness of 75D according to the present invention is consistently cooled down.

[0045] FIG. 4 is a graph showing the rate of crystallization as a function of time when the thermoplastic polyurethane having a hardness of 75D according to the present invention is abruptly cooled down to a specific temperature and maintained at the temperature.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0046] Hereinafter, the preferred embodiments of the present invention will be described in detail as follows. A representative embodiment of the present invention will be given in the following detailed description for the sake of accomplishing the above-specified technical objects of the present invention. The other embodiments available in the present invention are replaced by the description of the present invention.

[0047] The term nano-silica as used herein refers to silica having a particle size of 100 nm or less, and the term thermoplastic polyurethane yarn or TPU yarn as used herein means a monofilament or multifilament yarn made from a thermoplastic polyurethane resin. When the thermoplastic polyurethane yarn is referred to as being continuously produced, it can be continuously spun without yarn breakage during the cooling and drawing processes. The term spinning as used herein refers to any spinning process for synthetic fiber, such as dry spinning, wet spinning, electrospinning, etc., in addition to the melt spinning process based on melt extrusion as described in this specification. Although it is stated in this specification that a continuous spinning is carried out through the melt extrusion process in the production of a thermoplastic polyurethane yarn, the thermoplastic polyurethane yarn of the present invention can also be produced by dry spinning, wet spinning, electrospinning, etc. in addition to melt spinning.

[0048] The term low hardness as used herein refers to a hardness value (ranging from 0 to 100) determined by measuring with a Shore A durometer; and the term high hardness as used herein refers to a hardness value (ranging from 0 to 100) determined by measuring with a Shore D durometer. Accordingly, the term low-hardness (Shore A type) as used herein means having a hardness value determined by a Shore A durometer; and the term low-hardness (Shore D type) as used herein means having a hardness value determined by a Shore D durometer.

[0049] According to the present invention, in the production of thermoplastic polyurethane yarns (specifically, TPU monofilament or multifilament yarns) from a thermoplastic polyurethane composition including polyol, isocyanate, and glycol, the succinate prepared by mixing succinic acid as one of raw materials for thermoplastic polyurethane with adipic acid at a predetermined ratio is used to accelerate the crystallization rate of low-hardness (Shore A type; e.g., 98A, 90A, 70A) thermoplastic polyurethane resins in the melt extrusion process, thereby realizing a thermoplastic polyurethane yarn and a fabric made from the thermoplastic polyurethane yarn that enable a continuous spinning of yarns through melt spinning without yarn breakage during the cooling and drawing processes The production of yarns using low-hardness (Shore A type) thermoplastic polyurethane resins, which inherently have high tensile strength and high elongation, can realize thermoplastic polyurethane yarns with great stretch and recovery. But, the low-hardness (Shore A type) thermoplastic polyurethane resin has such a low crystallization rate that yarn breakage frequently takes place during the spinning process, more specifically, in the melt spinning process. For solving this problem, the present invention involves using succinate as a polyol and adding nano-silica to the thermoplastic polyurethane composition during the polymerization process to accelerate the crystallization rate in the melt spinning process, thereby realizing a continuous spinning of yarns without yarn breakage. The thermoplastic polyurethane yarn of the present invention thus obtained has a low hardness (Shore A) and hence great stretch and recovery. In this regard, it is natural that the fabric made from the thermoplastic polyurethane yarn of the present invention also has great stretch and recovery. Particularly, even if the thermoplastic polyurethane resin has a low hardness of 70A, it is possible not only to enable a continuous spinning of yarns without yarn breakage during the melt extrusion process but also to maintain great stretch and recovery.

[0050] As described above, the present invention uses succinate as a polyol component of a general thermoplastic polyurethane composition (polyol, isocyanate, glycol) and adds nano-silica having a particle size of 100 nm or less to the composition during the polymerization to accelerate the crystallization rate in the melt extrusion process of the thermoplastic polyurethane resin, thereby enabling a continuous spinning of yarns without yarn breakage during the cooling and drawing processes and producing a thermoplastic polyurethane yarn with great stretch and recovery. Naturally, the fabric made from the thermoplastic polyurethane yarn also has great stretch and recovery.

[0051] In this manner, for stably producing a thermoplastic polyurethane yarn, more specifically, realizing a continuous spinning of the thermoplastic polyurethane yarn without yarn breakage during the melt spinning process, it is very important to adjust the crystallinity of the thermoplastic polyurethane resin and also necessary to use nano-silica having a particle size of 100 nm or less as a processing aid. The thermoplastic polyurethane is a resin with a variable dynamic viscosity that depends on temperature. Therefore, the nano-silica as used in the present invention reduces the temperature-dependent change of viscosity (dynamic viscosity) of the thermoplastic polyurethane resin in the production of thermoplastic polyurethane yarns to realize the stable melt extrusion of the thermoplastic polyurethane resin and thereby to produce a yarn with a uniform thickness.

[0052] For thick (about 350 denier or above) monofilament yarns, it is possible to produce yarns stably using silica of a regular size. On the other hand, for thin (50 to 350 denier) monofilament yarns, the use of regular-sized silica causes yarn breakage during the cooling and drawing processes. To solve this problem, nano-silica having a particle size of 100 nm or less is used to continuously produce a thermoplastic polyurethane yarn.

[0053] For production of a multifilament yarn, which involves spinning a single filament of fiber to a low thickness of 50 denier or less, a high-hardness (Shore D: 75D for example) thermoplastic polyurethane (TPU) has a high crystallization rate, but with a take-up velocity of 1,000 rpm at maximum, so it is impossible to increase the take-up velocity by using nano-silica alone, and yarn breakage occurs unavoidably during the cooling and drawing processes. Therefore, the present invention involves using succinate in combination with nano-silica for the purpose of increasing the take-up velocity in the production of multifilament yarns, to accelerate the crystallization rate during the cooling and drawing processes and to realize a continuous spinning without yarn breakage. Naturally, great stretch and recovery can be secured when producing multifilament yarns from low-hardness (Shore A type) thermoplastic polyurethane resins.

[0054] In the production of thermoplastic polyurethane yarns according to the present invention, a polyol is prepared by mixing succinic acid and adipic acid at a defined mixing ratio depending on the use purpose (i.e., elongation of yarns or fabric) and then polymerized with a thermoplastic polyurethane composition to prepare a thermoplastic polyurethane resin. In this regard, the thermoplastic polyurethane resin can be prepared in the presence of nano-silica added as a processing aid during the polymerization process or using a separate master batch. The use of the resultant thermoplastic polyurethane resin in making monofilament or multifilament yarns secures a continuous spinning of yarns without yarn breakage during the melt extrusion process and results in producing a variety of thermoplastic polyurethane yarns, particularly ranging from low-hardness (Shore A type) thermoplastic polyurethane yarns with great stretch and recovery to high-hardness (Shore D type) thermoplastic polyurethane yarns, and fabrics using the thermoplastic polyurethane yarns.

[0055] As described above, the thermoplastic polyurethane yarn of the present invention contains a general thermoplastic polyurethane composition composed of polyol, isocyanate, and glycol. Particularly, the polyol as used herein is succinate (e.g., 1,4-bd succinate using succinic acid), and nano-silica having a particle size of 100 nm or less is added to the thermoplastic polyurethane composition during the polymerization. In this regard, the polyol may include adipate (e.g., 1,4-bd adipate using adipic acid) according to the present invention. The polyol as used herein may further include glutaric acid, heptanedioic acid, suberic acid, azelaic acid, sebacic acid, dodecanedioic acid, isophthalic acid, terephthalic acid, cyclohexanoic acid, or dicarboxylic acid.

[0056] The general thermoplastic polyurethane composition includes isocyanate and glycol. The isocyanate includes aromatic isocyanate and aliphatic isocyanate, specifically including MDI, XDI, H12MDI, HDI, TDI, IPDI, LDI, BDI, PDI, CHDI, TODI, NDI, etc., which are used alone or in combination. The term glycol as used herein means a short-chain glycol, specifically including ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, butanediol, hexanediol, pentanediol, neopentyl glycol, cyclohexane dimethanol, hexamethylenediol, heptanediol, nonanediol, dodecanediol, etc., which are used alone or in combination.

[0057] In the following description of this disclosure, there is provided a preferred embodiment of the present invention that involves using succinate as a polyol component of a general thermoplastic polyurethane composition (isocyanate and glycol) in the production of a thermoplastic polyurethane yarn and adding nano-silica having a particle size of 100 nm or less during the polymerization of the composition to accelerate the crystallization rate in the melt extrusion process, thereby enabling a continuous spinning of yarns without yarn breakage during the cooling and drawing processes in the production of yarns from low-hardness (Shore A type) thermoplastic polyurethane resins with great stretch and recovery. There is also specifically provided another preferred embodiment of the present invention that realizes a continuous spinning of yarns not only in the production of multifilament yarns using a high-hardness (Shore D type) thermoplastic polyurethane resin without yarn breakage but also in the production of low-hardness (Shore A type) multifilament yarns having great stretch and recovery without yarn breakage during the cooling and drawing processes.

Example 1

[0058] An example is given to describe that succinate and nano-silica are used in the production of a thermoplastic polyurethane yarn to accelerate the crystallization rate during the cooling and drawing processes.

[0059] FIGS. 1 to 4 are graphs showing the crystallization rate analyzed by the differential scanning calorimetry (DSC). The conditions of the DSC analysis on the crystallization rate are given as follows:

[0060] 1. Heating from 25 C. to 250 C., Rate 10 C./min.

[0061] 2. Equilibrium for 2 minutes.

[0062] 3. Cooling to crystallization temperature, Rate 10 C./min.

[0063] 4. Isotherm for 15 minutes.

[0064] * Crystallization temperature

[0065] T-90AB, M6, M7: 90 C.

[0066] T-75D, M3: 150 C.

[0067] In this regard, T-90AB is a thermoplastic polyurethane resin having a succinate content of 0% and an adipate content of 61% with a hardness of 90A; M6 is a thermoplastic polyurethane resin having a succinate content of 30% and an adipate content of 31% with a hardness of 90A; M7 is a thermoplastic polyurethane resin having a succinate content of 40% and an adipate content of 21% with a hardness of 90A; T-75D is a thermoplastic polyurethane resin having a succinate content of 0% and an adipate content of 35% with a hardness of 75D; and M3 is a thermoplastic polyurethane resin having a succinate content of 20% and an adipate content of 15% with a hardness of 75D.

[0068] Generally, crystals dissociated (melted) by heating get to recrystallization by cooling; FIG. 1 shows the cooling process. Referring to the graph of FIG. 1, with the progress of cooling, M6 and M7 get to exothermic (the upper peak) recrystallization at higher temperature than T-90AB, and M7 starts to recrystallize at a little higher temperature than M6. The polymer more prone to crystallization is recrystallized at higher temperature; therefore, the thermoplastic polyurethane resins can be arranged as M7>M6>T-90AB in order of decreasing likelihood of recrystallization.

[0069] FIG. 2 is a graph showing the rate of crystallization as a function of time when the thermoplastic polyurethane having a hardness of 90A is abruptly cooled down to a specific temperature (90 C.) and maintained at the temperature. As shown in the graph of FIG. 2, M7 gets to the exothermic process (recrystallization) in the shortest period of time; and M6 takes time almost the same as or shorter than T-90AB to get to the exothermic process. Namely, the thermoplastic polyurethane resins can be arranged as M7>M6>T-90AB in order of decreasing crystallization rate.

[0070] More specifically, the crystallization time of thermoplastic polyurethane resins with a hardness of 90A is 18.26 min for T-90AB having a succinate content of 0%, 18.23 min for M6 having a succinate content of 30%, and 17.66 min for M7 having a succinate content of 40%. It can be seen from the data that the crystallization rate increases with an increase in the succinate content.

[0071] Referring to FIGS. 3 and 4, M3 gets to recrystallization at higher temperature and is far more prone to crystallization than T-75D. An isothermal crystallization testing shows that M3 gets to crystallization much faster than T-75D; that is, M3 has the higher crystallization rate. More specifically, the crystallization time of thermoplastic polyurethane resins with a hardness of 75D is 25.88 min for T75D having a succinate content of 0%, and 21.44 min for M3 having a succinate content of 20%. In conclusion, the crystallization rate increases with an increase in the succinate content.

Example 2

[0072] Tables 1 to 6 present the mixing ratios of the individual compositions for production of the thermoplastic polyurethane yarns of the present invention from thermoplastic polyurethane (TPU) having a hardness of 75D. In other words, the following tables specifically show the elongation and processability of the thermoplastic polyurethane yarns with succinate and nano-silica contents under control. The elongation measurement of the thermoplastic polyurethane yarn was all the same for multifilament and monofilament yarns. The term elongation as used herein refers to the ability of stretch and recovery of the thermoplastic polyurethane yarn; and the term processability means the spinnability of yarns in the cooling and drawing processes during melt extrusion in the production of thermoplastic polyurethane yarns.

[0073] The general thermoplastic polyurethane composition, specifically the isocyanate and glycol contents, as presented in each of the following tables do not affect the objects and effects of the present invention, so the isocyanate and glycol contents should not be construed as limiting the scope of the invention. This is applied equally to all the following tables.

TABLE-US-00001 TABLE 1 TPU composition (100%) Succinate content (0.0%), Adipate content (35.0%), Glycol content (15.0%), Isocyanate content (50.0%) Processability Nano-silica Multifilament yarn content Elongation (5 denier, 36 Monofilament yarn (phr) (%) filler) (150 to 200 denier) 0.0 54 Yarn breakage Good processability (Not working) during extrusion, Yarn breakage 30% 0.5 58 Good Good processability processability during extrusion, during extrusion, Yarn breakage 20% Yarn breakage 15% 1.0 60 Good Good processability processability during extrusion, during extrusion, Yarn breakage 10% Yarn breakage 20% 2.0 62 Good Too slippery processability surface and extreme during extrusion, crystallization Yarn breakage 25% 3.0 65 Too slippery Too slippery surface and surface and extreme extreme crystallization crystallization 5.0 64 Too slippery Too slippery surface and surface and extreme extreme crystallization crystallization

TABLE-US-00002 TABLE 2 TPU composition (100%) Succinate content (5.0%), Adipate content (30.0%), Glycol content (15.0%), Isocyanate content (50.0%) Processability Nano-silica Multifilament yarn content Elongation (5 denier, 36 Monofilament yarn (phr) (%) filler) (150 to 200 denier) 0.0 52 Yarn breakage Good processability (Not working) during extrusion, Yarn breakage 20% 0.5 54 Good Good processability processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 1.0 59 Good Good processability processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 2.0 61 Good Good processability processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 3.0 59 Good Good processability processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 5.0 55 Too slippery Too slippery surface and surface and extreme extreme crystallization crystallization

TABLE-US-00003 TABLE 3 TPU composition (100%) Succinate content (10.0%), Adipate content (25.0%), Glycol content (15.0%), Isocyanate content (50.0%) Processability Nano-silica Multifilament yarn content Elongation (5 denier, 36 Monofilament yarn (phr) (%) filler) (150 to 200 denier) 0.0 57 Yarn breakage Good processability (Not working) during extrusion, Yarn breakage 20% 0.5 60 Good Good processability processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 1.0 65 Good Good processability processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 2.0 64 Good Good processability processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 3.0 68 Good Good processability processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 5.0 62 Too slippery Too slippery surface and surface and extreme extreme crystallization crystallization

TABLE-US-00004 TABLE 4 TPU composition (100%) Succinate content (20.0%), Adipate content (15.0%), Glycol content (15.0%), Isocyanate content (50.0%) Processability Nano-silica Multifilament yarn content Elongation (5 denier, 36 Monofilament yarn (phr) (%) filler) (150 to 200 denier) 0.0 59 Yarn breakage Good processability (Not working) during extrusion, Yarn breakage 15% 0.5 62 Good Good processability processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 1.0 66 Good Good processability processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 2.0 70 Good Good processability processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 3.0 68 Good Good processability processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 5.0 63 Too slippery Too slippery surface and surface and extreme extreme crystallization crystallization

TABLE-US-00005 TABLE 5 TPU composition (100%) Succinate content (30.0%), Adipate content (5.0%), Glycol content (15.0%), Isocyanate content (50.0%) Processability Nano-silica Multifilament yarn content Elongation (5 denier, 36 Monofilament yarn (phr) (%) filler) (150 to 200 denier) 0.0 64 Yarn breakage Good processability (Not working) during extrusion, Yarn breakage 15% 0.5 67 Good Good processability processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 1.0 71 Good Good processability processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 2.0 70 Good Good processability processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 3.0 72 Good Good processability processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 5.0 70 Too slippery Too slippery surface and surface and extreme extreme crystallization crystallization

TABLE-US-00006 TABLE 6 TPU composition (100%) Succinate content (35.0%), Adipate content (0.0%), Glycol content (15.0%), Isocyanate content (50.0%) Nano-silica Processability content Elongation Multifilament yarn Monofilament yarn (phr) (%) (5 denier, 36 filler) (150 to 200 denier) 0.0 56 Yarn breakage Good processability (Not working) during extrusion, Yarn breakage 10% 0.5 59 Yarn breakage Good processability (Not working) during extrusion, Yarn breakage 10% 1.0 58 Yarn breakage Too slippery (Not working) surface and extreme crystallization 2.0 56 Too slippery Too slippery surface and extreme surface and extreme crystallization crystallization 3.0 52 Too slippery Too slippery surface and extreme surface and extreme crystallization crystallization 5.0 49 Too slippery Too slippery surface and extreme surface and extreme crystallization crystallization

[0074] As can be seen from Tables 1 to 6, the production of multifilament and monofilament yarns from a thermoplastic polyurethane having a hardness of 75D is impossible to accomplish merely with a succinate content of less than 5% due to low crystallization rate, but successfully realized with a succinate content of 5 to 30% that accelerates the crystallization rate. The succinate content of greater than 30% increases the crystallization rate extremely high, causing yarn breakage too frequently to produce monofilament or multifilament yarns. Meanwhile, the elongation is increased (by about 5 to 25%) with an increase in the succinate content of the thermoplastic polyurethane.

[0075] In the present invention, nano-silica is used in combination with succinate in order to prevent yarn breakage during the cooling and drawing processes. For thermoplastic polyurethane having a hardness of 75D, the nano-silica content of 0.5 to 3.0 phr realizes a continuous spinning of yarns without yarn breakage; and the nano-silica content of 5.0 phr results in too slippery surface and extreme crystallization, causing occasional yarn breakage, but no problem in continuously spinning the yarns.

Example 3

[0076] Tables 7 to 13 present the mixing ratios of the individual compositions for production of the thermoplastic polyurethane yarns of the present invention from thermoplastic polyurethane (TPU) having a hardness of 60D. In other words, the following tables specifically show the elongation and processability of the thermoplastic polyurethane yarns with succinate and nano-silica contents under control.

TABLE-US-00007 TABLE 7 TPU composition (100%) Succinate content (0.0%), Adipate content (43.0%), Glycol content (13.0%), Isocyanate content (44.0%) Nano-silica Processability content Elongation Multifilament yarn Monofilament yarn (phr) (%) (5 denier, 36 filler) (150 to 200 denier) 0.0 63 Yarn breakage Good processability (Not working) during extrusion, Yarn breakage 20% 0.5 64 Good processability Good processability during extrusion, during extrusion, Yarn breakage 25% Yarn breakage 15% 1.0 68 Good processability Good processability during extrusion, during extrusion, Yarn breakage 25% Good surface without yarn breakage 2.0 69 Good processability Good processability during extrusion, during extrusion, Yarn breakage 25% Good surface without yarn breakage 3.0 67 Good processability Good processability during extrusion, during extrusion, Yarn breakage 25% Good surface without yarn breakage 5.0 61 Too slippery Too slippery surface and extreme surface and extreme crystallization crystallization

TABLE-US-00008 TABLE 8 TPU composition (100%) Succinate content (5.0%), Adipate content (38.0%), Glycol content (13.0%), Isocyanate content (44.0%) Nano-silica Processability content Elongation Multifilament yarn Monofilament yarn (phr) (%) (5 denier, 36 filler) (150 to 200 denier) 0.0 68 Yarn breakage Good processability (Not working) during extrusion, Yarn breakage 15% 0.5 67 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 1.0 72 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 2.0 76 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 3.0 72 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 5.0 65 Too slippery Too slippery surface and extreme surface and extreme crystallization crystallization

TABLE-US-00009 TABLE 9 TPU composition (100%) Succinate content (10.0%), Adipate content (33.0%), Glycol content (13.0%), Isocyanate content (44.0%) Nano-silica Processability content Elongation Multifilament yarn Monofilament yarn (phr) (%) (5 denier, 36 filler) (150 to 200 denier) 0.0 69 Yarn breakage Good processability (Not working) during extrusion, Yarn breakage 15% 0.5 73 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 1.0 75 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 2.0 76 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 3.0 78 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 5.0 70 Too slippery Too slippery surface and extreme surface and extreme crystallization crystallization

TABLE-US-00010 TABLE 10 TPU composition (100%) Succinate content (20.0%), Adipate content (23.0%), Glycol content (13.0%), Isocyanate content (44.0%) Nano-silica Processability content Elongation Multifilament yarn Monofilament yarn (phr) (%) (5 denier, 36 filler) (150 to 200 denier) 0.0 71 Yarn breakage Good processability (Not working) during extrusion, Yarn breakage 15% 0.5 76 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 1.0 75 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 2.0 78 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 3.0 73 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 5.0 70 Too slippery Too slippery surface and extreme surface and extreme crystallization crystallization

TABLE-US-00011 TABLE 11 TPU composition (100%) Succinate content (30.0%), Adipate content (13.0%), Glycol content (13.0%), Isocyanate content (44.0%) Nano-silica Processability content Elongation Multifilament yarn Monofilament yarn (phr) (%) (5 denier, 36 filler) (150 to 200 denier) 0.0 70 Yarn breakage Good processability (Not working) during extrusion, Yarn breakage 15% 0.5 73 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 1.0 76 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 2.0 76 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 3.0 74 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 5.0 67 Too slippery Too slippery surface and extreme surface and extreme crystallization crystallization

TABLE-US-00012 TABLE 12 TPU composition (100%) Succinate content (40.0%), Adipate content (3.0%), Glycol content (13.0%), Isocyanate content (44.0%) Nano-silica Processability content Elongation Multifilament yarn Monofilament yarn (phr) (%) (5 denier, 36 filler) (150 to 200 denier) 0.0 68 Yarn breakage Good processability (Not working) during extrusion, Yarn breakage 15% 0.5 70 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 1.0 73 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 2.0 70 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 3.0 73 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 5.0 65 Too slippery Too slippery surface and extreme surface and extreme crystallization crystallization

TABLE-US-00013 TABLE 13 TPU composition (100%) Succinate content (43.0%), Adipate content (0.0%), Glycol content (13.0%), Isocyanate content (44.0%) Nano-silica Processability content Elongation Multifilament yarn Monofilament yarn (phr) (%) (5 denier, 36 filler) (150 to 200 denier) 0.0 62 Yarn breakage Good processability (Not working) during extrusion, Yarn breakage 15% 0.5 58 Yarn breakage Good processability (Not working) during extrusion, Yarn breakage 15% 1.0 61 Yarn breakage Too slippery (Not working) surface and extreme crystallization 2.0 64 Too slippery Too slippery surface and extreme surface and extreme crystallization crystallization 3.0 59 Too slippery Too slippery surface and extreme surface and extreme crystallization crystallization 5.0 55 Too slippery Too slippery surface and extreme surface and extreme crystallization crystallization

[0077] As can be seen from Tables 7 to 13, the production of multifilament and monofilament yarns from a thermoplastic polyurethane having a hardness of 60D is impossible to accomplish merely with a succinate content of less than 5% due to low crystallization rate, but successfully realized with a succinate content of 5 to 40% that accelerates the crystallization rate. The succinate content of greater than 40% increases the crystallization rate extremely high, causing yarn breakage too frequently to produce monofilament or multifilament yarns. Meanwhile, the elongation is increased (by about 5 to 20%) with an increase in the succinate content of the thermoplastic polyurethane.

[0078] In the present invention, nano-silica is used in combination with succinate in order to prevent yarn breakage during the cooling and drawing processes. For thermoplastic polyurethane having a hardness of 60D, the nano-silica content of 0.5 to 3.0 phr realizes a continuous spinning of yarns without yarn breakage; and the nano-silica content of 5.0 phr results in too slippery surface and extreme crystallization, causing occasional yarn breakage, but no problem in continuously spinning the yarns.

Example 4

[0079] Tables 14 to 21 present the mixing ratios of the individual compositions for production of the thermoplastic polyurethane yarns of the present invention from thermoplastic polyurethane (TPU) having a hardness of 98A. In other words, the following tables specifically show the elongation and processability of the thermoplastic polyurethane yarns with succinate and nano-silica contents under control.

TABLE-US-00014 TABLE 14 TPU composition (100%) Succinate content (0.0%), Adipate content (48.5%), Glycol content (10.5%), Isocyanate content (41.0%) Nano-silica Processability content Elongation Multifilament yarn Monofilament yarn (phr) (%) (5 denier, 36 filler) (150 to 200 denier) 0.0 82 Yarn breakage Good processability (Not working) during extrusion, Yarn breakage 20% 0.5 86 Yarn breakage Good processability (Not working) during extrusion, Yarn breakage 20% 1.0 90 Yarn breakage Good processability (Not working) during extrusion, Good surface without yarn breakage 2.0 94 Good processability Good processability during extrusion, during extrusion, Yarn breakage 30% Good surface without yarn breakage 3.0 92 Good processability Good processability during extrusion, during extrusion, Yarn breakage 30% Good surface without yarn breakage 5.0 88 Good processability Good processability during extrusion, during extrusion, Yarn breakage 30% Good surface without yarn breakage

TABLE-US-00015 TABLE 15 TPU composition (100%) Succinate content (5.0%), Adipate content (43.5%), Glycol content (10.5%), Isocyanate content (41.0%) Nano-silica Processability content Elongation Multifilament yarn Monofilament yarn (phr) (%) (5 denier, 36 filler) (150 to 200 denier) 0.0 81 Yarn breakage Good processability (Not working) during extrusion, Yarn breakage 20% 0.5 86 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 1.0 94 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 2.0 95 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 3.0 93 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 5.0 87 Too slippery Too slippery surface and extreme surface and extreme crystallization crystallization

TABLE-US-00016 TABLE 16 TPU composition (100%) Succinate content (10.0%), Adipate content (38.5%), Glycol content (10.5%), Isocyanate content (41.0%) Nano-silica Processability content Elongation Multifilament yarn Monofilament yarn (phr) (%) (5 denier, 36 filler) (150 to 200 denier) 0.0 89 Yarn breakage Good processability (Not working) during extrusion, Yarn breakage 15% 0.5 96 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 1.0 101 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 2.0 105 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 3.0 100 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 5.0 98 Too slippery Too slippery surface and extreme surface and extreme crystallization crystallization

TABLE-US-00017 TABLE 17 TPU composition (100%) Succinate content (20.0%), Adipate content (28.5%), Glycol content (10.5%), Isocyanate content (41.0%) Nano-silica Processability content Elongation Multifilament yarn Monofilament yarn (phr) (%) (5 denier, 36 filler) (150 to 200 denier) 0.0 94 Yarn breakage Good processability (Not working) during extrusion, Yarn breakage 15% 0.5 97 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 1.0 106 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 2.0 108 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 3.0 100 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 5.0 95 Too slippery Too slippery surface and extreme surface and extreme crystallization crystallization

TABLE-US-00018 TABLE 18 TPU composition (100%) Succinate content (30.0%), Adipate content (18.5%), Glycol content (10.5%), Isocyanate content (41.0%) Nano-silica Processability content Elongation Multifilament yarn Monofilament yarn (phr) (%) (5 denier, 36 filler) (150 to 200 denier) 0.0 92 Yarn breakage Good processability (Not working) during extrusion, Yarn breakage 10% 0.5 96 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 1.0 101 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 2.0 103 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 3.0 100 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 5.0 96 Too slippery Too slippery surface and extreme surface and extreme crystallization crystallization

TABLE-US-00019 TABLE 19 TPU composition (100%) Succinate content (40.0%), Adipate content (8.5%), Glycol content (10.5%), Isocyanate content (41.0%) Nano-silica Processability content Elongation Multifilament yarn Monofilament yarn (phr) (%) (5 denier, 36 filler) (150 to 200 denier) 0.0 93 Yarn breakage Good processability (Not working) during extrusion, Yarn breakage 10% 0.5 98 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 1.0 103 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 2.0 106 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 3.0 103 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 5.0 95 Too slippery Too slippery surface and extreme surface and extreme crystallization crystallization

TABLE-US-00020 TABLE 20 TPU composition (100%) Succinate content (45.0%), Adipate content (3.5%), Glycol content (10.5%), Isocyanate content (41.0%) Nano-silica Processability content Elongation Multifilament yarn Monofilament yarn (phr) (%) (5 denier, 36 filler) (150 to 200 denier) 0.0 97 Yarn breakage Good processability (Not working) during extrusion, Yarn breakage 10% 0.5 100 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 1.0 106 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 2.0 105 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 3.0 102 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 5.0 100 Too slippery Too slippery surface and extreme surface and extreme crystallization crystallization

TABLE-US-00021 TABLE 21 TPU composition (100%) Succinate content (48.5%), Adipate content (0.0%), Glycol content (10.5%), Isocyanate content (41.0%) Nano-silica Processability content Elongation Multifilament yarn Monofilament yarn (phr) (%) (5 denier, 36 filler) (150 to 200 denier) 0.0 92 Yarn breakage Good processability (Not working) during extrusion, Yarn breakage 15% 0.5 95 Yarn breakage Good processability (Not working) during extrusion, Yarn breakage 15% 1.0 95 Yarn breakage Too slippery (Not working) surface and extreme crystallization 2.0 94 Too slippery Too slippery surface and extreme surface and extreme crystallization crystallization 3.0 90 Too slippery Too slippery surface and extreme surface and extreme crystallization crystallization 5.0 89 Too slippery Too slippery surface and extreme surface and extreme crystallization crystallization

[0080] As can be seen from Tables 14 to 21, the production of multifilament and monofilament yarns from a thermoplastic polyurethane having a hardness of 98A is impossible to accomplish merely with a succinate content of less than 5% due to low crystallization rate, but successfully realized with a succinate content of 5 to 45% that accelerates the crystallization rate. The succinate content of greater than 45% increases the crystallization rate extremely high, causing yarn breakage too frequently to produce monofilament or multifilament yarns. Particularly, although low-hardness (Shore 98A) thermoplastic polyurethane is used in the production of thermoplastic polyurethane yarns, it is possible not only to impart great stretch and recovery but also to realize a continuous spinning of yarns without yarn breakage during the cooling and drawing processes. Meanwhile, the elongation is increased (by about 5 to 20%) with an increase in the succinate content of the thermoplastic polyurethane.

[0081] In the present invention, nano-silica is used in combination with succinate in order to prevent yarn breakage during the cooling and drawing processes. For thermoplastic polyurethane having a hardness of 98A, the nano-silica content of 0.5 to 3.0 phr realizes a continuous spinning of yarns without yarn breakage; and the nano-silica content of 5.0 phr results in too slippery surface and extreme crystallization, causing occasional yarn breakage, but no problem in continuously spinning the yarns.

Example 5

[0082] Tables 22 to 29 present the mixing ratios of the individual compositions for production of the thermoplastic polyurethane yarns of the present invention from thermoplastic polyurethane (TPU) having a hardness of 90A. In other words, the following tables specifically show the elongation and processability of the thermoplastic polyurethane yarns with succinate and nano-silica contents under control.

TABLE-US-00022 TABLE 22 TPU composition (100%) Succinate content (5.0%), Adipate content (56.0%), Glycol content (6.5%), Isocyanate content (32.5%) Nano-silica Processability content Elongation Multifilament yarn Monofilament yarn (phr) (%) (5 denier, 36 filler) (150 to 200 denier) 0.0 156 Yarn breakage Good processability (Not working) during extrusion, Yarn breakage 50% 0.5 162 Yarn breakage Good processability (Not working) during extrusion, Yarn breakage 25% 1.0 168 Yarn breakage Good processability (Not working) during extrusion, Yarn breakage 25% 2.0 172 Good processability Good processability during extrusion, during extrusion, Yarn breakage 30% Yarn breakage 25% 3.0 165 Good processability Good processability during extrusion, during extrusion, Yarn breakage 30% Yarn breakage 15% 5.0 164 Good processability Good processability during extrusion, during extrusion, Yarn breakage 30% Yarn breakage 15%

TABLE-US-00023 TABLE 23 TPU composition (100%) Succinate content (10.0%), Adipate content (51.0%), Glycol content (6.5%), Isocyanate content (32.5%) Nano-silica Processability content Elongation Multifilament yarn Monofilament yarn (phr) (%) (5 denier, 36 filler) (150 to 200 denier) 0.0 163 Yarn breakage Good processability (Not working) during extrusion, Yarn breakage 20% 0.5 169 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 1.0 175 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 2.0 173 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 3.0 176 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 5.0 170 Too slippery Too slippery surface and extreme surface and extreme crystallization crystallization

TABLE-US-00024 TABLE 24 TPU composition (100%) Succinate content (20.0%), Adipate content (41.0%), Glycol content (6.5%), Isocyanate content (32.5%) Nano-silica Processability content Elongation Multifilament yarn Monofilament yarn (phr) (%) (5 denier, 36 filler) (150 to 200 denier) 0.0 170 Yarn breakage Good processability (Not working) during extrusion, Yarn breakage 15% 0.5 173 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 1.0 182 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 2.0 186 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 3.0 182 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 5.0 182 Too slippery Too slippery surface and extreme surface and extreme crystallization crystallization

TABLE-US-00025 TABLE 25 TPU composition (100%) Succinate content (30.0%), Adipate content (31.0%), Glycol content (6.5%), Isocyanate content (32.5%) Nano-silica Processability content Elongation Multifilament yarn Monofilament yarn (phr) (%) (5 denier, 36 filler) (150 to 200 denier) 0.0 176 Yarn breakage Good processability (Not working) during extrusion, Yarn breakage 15% 0.5 186 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 1.0 193 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 2.0 192 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 3.0 193 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 5.0 189 Too slippery Too slippery surface and extreme surface and extreme crystallization crystallization

TABLE-US-00026 TABLE 26 TPU composition (100%) Succinate content (40.0%), Adipate content (21.0%), Glycol content (6.5%), Isocyanate content (32.5%) Nano-silica Processability content Elongation Multifilament yarn Monofilament yarn (phr) (%) (5 denier, 36 filler) (150 to 200 denier) 0.0 181 Yarn breakage Good processability (Not working) during extrusion, Yarn breakage 10% 0.5 183 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 1.0 182 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 2.0 179 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 3.0 178 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 5.0 176 Too slippery Too slippery surface and extreme surface and extreme crystallization crystallization

TABLE-US-00027 TABLE 27 TPU composition (100%) Succinate content (50.0%), Adipate content (11.0%), Glycol content (6.5%), Isocyanate content (32.5%) Nano-silica Processability content Elongation Multifilament yarn Monofilament yarn (phr) (%) (5 denier, 36 filler) (150 to 200 denier) 0.0 180 Yarn breakage Good processability (Not working) during extrusion, Yarn breakage 10% 0.5 182 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 1.0 186 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 2.0 179 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 3.0 176 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 5.0 170 Too slippery Too slippery surface and extreme surface and extreme crystallization crystallization

TABLE-US-00028 TABLE 28 TPU composition (100%) Succinate content (55.0%), Adipate content (6.0%), Glycol content (6.5%), Isocyanate content (32.5%) Nano-silica Processability content Elongation Multifilament yarn Monofilament yarn (phr) (%) (5 denier, 36 filler) (150 to 200 denier) 0.0 182 Yarn breakage Good processability (Not working) during extrusion, Yarn breakage 10% 0.5 183 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 1.0 180 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 2.0 182 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 3.0 185 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 5.0 172 Too slippery Too slippery surface and extreme surface and extreme crystallization crystallization

TABLE-US-00029 TABLE 29 TPU composition (100%) Succinate content (61.0%), Adipate content (0.0%), Glycol content (6.5%), Isocyanate content (32.5%) Nano-silica Processability content Elongation Multifilament yarn Monofilament yarn (phr) (%) (5 denier, 36 filler) (150 to 200 denier) 0.0 172 Yarn breakage Good processability (Not working) during extrusion, Yarn breakage 15% 0.5 182 Yarn breakage Good processability (Not working) during extrusion, Yarn breakage 15% 1.0 183 Yarn breakage Good processability (Not working) during extrusion, Yarn breakage 20% 2.0 179 Yarn breakage Good processability (Not working) during extrusion, Yarn breakage 25% 3.0 175 Yarn breakage Too slippery (Not working) surface and extreme crystallization 5.0 174 Too slippery Too slippery surface and extreme surface and extreme crystallization crystallization

[0083] As can be seen from Tables 22 to 29, the production of multifilament and monofilament yarns from a thermoplastic polyurethane having a hardness of 90A is impossible to accomplish merely with a succinate content of less than 10% due to low crystallization rate, but successfully realized with a succinate content of 10 to 55% that accelerates the crystallization rate. The succinate content of greater than 55% increases the crystallization rate extremely high, causing yarn breakage too frequently to produce monofilament or multifilament yarns. Particularly, although low-hardness (Shore 90A) thermoplastic polyurethane is used in the production of thermoplastic polyurethane yarns, it is possible not only to impart great stretch and recovery but also to realize a continuous spinning of yarns without yarn breakage during the cooling and drawing processes. Meanwhile, the elongation is increased (by about 5 to 20%) with an increase in the succinate content of the thermoplastic polyurethane.

[0084] In the present invention, nano-silica is used in combination with succinate in order to prevent yarn breakage during the cooling and drawing processes. For thermoplastic polyurethane having a hardness of 90A, the nano-silica content of 0.5 to 3.0 phr realizes a continuous spinning of yarns without yarn breakage; and the nano-silica content of 5.0 phr results in too slippery surface and extreme crystallization, causing occasional yarn breakage, but no problem in continuously spinning the yarns.

Example 6

[0085] Tables 30 to 38 present the mixing ratios of the individual compositions for production of the thermoplastic polyurethane yarns of the present invention from thermoplastic polyurethane (TPU) having a hardness of 70A. In other words, the following tables specifically show the elongation and processability of the thermoplastic polyurethane yarns with succinate and nano-silica contents under control.

TABLE-US-00030 TABLE 30 TPU composition (100%) Succinate content (15.0%), Adipate content (62.5%), Glycol content (2.5%), Isocyanate content (20.0%) Nano-silica Processability content Elongation Multifilament yarn Monofilament yarn (phr) (%) (5 denier, 36 filler) (150 to 200 denier) 0.0 254 Yarn breakage Good processability (Not working) during extrusion, Yarn breakage 50% 0.5 248 Yarn breakage Good processability (Not working) during extrusion, Yarn breakage 50% 1.0 257 Yarn breakage Good processability (Not working) during extrusion, Yarn breakage 30% 2.0 258 Yarn breakage Good processability (Not working) during extrusion, Yarn breakage 30% 3.0 256 Yarn breakage Good processability (Not working) during extrusion, Yarn breakage 30% 5.0 247 Yarn breakage Good processability (Not working) during extrusion, Yarn breakage 30%

TABLE-US-00031 TABLE 31 TPU composition (100%) Succinate content (20.0%), Adipate content (57.5%), Glycol content (2.5%), Isocyanate content (20.0%) Processability Nano-silica Elongation Multifilament yarn Monofilament yarn content (%) (5 denier, 36 filler) (150 to 200 denier) 0.0 258 Yarn breakage Good processability (Not working) during extrusion, Yarn breakage 30% 0.5 255 Yarn breakage Good processability (Not working) during extrusion, Yarn breakage 15% 1.0 261 Yarn breakage Good processability (Not working) during extrusion, Good surface without yarn breakage 2.0 264 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 3.0 261 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 5.0 254 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage

TABLE-US-00032 TABLE 32 TPU composition (100%) Succinate content (30.0%), Adipate content (47.5%), Glycol content (2.5%), Isocyanate content (20.0%) Nano-silica Processability content Elongation Multifilament yarn Monofilament yarn (phr) (%) (5 denier, 36 filler) (150 to 200 denier) 0.0 251 Yarn breakage Good processability (Not working) during extrusion, Yarn breakage 20% 0.5 261 Yarn breakage Good processability (Not working) during extrusion, Good surface without yarn breakage 1.0 264 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 2.0 266 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 3.0 267 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 5.0 260 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage

TABLE-US-00033 TABLE 33 TPU composition (100%) Succinate content (40.0%), Adipate content (37.5%), Glycol content (2.5%), Isocyanate content (20.0%) Nano-silica Processability content Elongation Multifilament yarn Monofilament yarn (phr) (%) (5 denier, 36 filler) (150 to 200 denier) 0.0 268 Yarn breakage Good processability (Not working) during extrusion, Yarn breakage 20% 0.5 270 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 1.0 283 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 2.0 291 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 3.0 287 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 5.0 283 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage

TABLE-US-00034 TABLE 34 TPU composition (100%) Succinate content (50.0%), Adipate content (27.5%), Glycol content (2.5%), Isocyanate content (20.0%) Nano-silica Processability content Elongation Multifilament yarn Monofilament yarn (phr) (%) (5 denier, 36 filler) (150 to 200 denier) 0.0 276 Yarn breakage Good processability (Not working) during extrusion, Yarn breakage 15% 0.5 291 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 1.0 289 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 2.0 298 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 3.0 290 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 5.0 283 Good processability Good processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage

TABLE-US-00035 TABLE 35 TPU Succinate content (60.0%), Adipate content (17.5%), composition Glycol content (2.5%), Isocyanate content (20.0%) (100%) Processability Nano-silica Multifilament yarn content Elongation (5 denier, 36 Monofilament yarn (phr) (%) filler) (150 to 200 denier) 0.0 284 Yarn breakage Good processability (Not working) during extrusion, Yarn breakage 15% 0.5 296 Good Good processability processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 1.0 299 Good Good processability processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 2.0 311 Good Good processability processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 3.0 306 Good Good processability processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 5.0 291 Good Good processability processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage

TABLE-US-00036 TABLE 36 TPU Succinate content (70.0%), Adipate content (7.5%), composition Glycol content (2.5%), Isocyanate content (20.0%) (100%) Processability Nano-silica Multifilament yarn content Elongation (5 denier, 36 Monofilament yarn (phr) (%) filler) (150 to 200 denier) 0.0 301 Yarn breakage Good processability (Not working) during extrusion, Yarn breakage 15% 0.5 297 Good Good processability processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 1.0 316 Good Good processability processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 2.0 310 Good Good processability processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 3.0 317 Good Good processability processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 5.0 311 Good Good processability processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage

TABLE-US-00037 TABLE 37 TPU Succinate content (75.0%), Adipate content (2.5%), composition Glycol content (2.5%), Isocyanate content (20.0%) (100%) Processability Nano-silica Multifilament yarn content Elongation (5 denier, 36 Monofilament yarn (phr) (%) filler) (150 to 200 denier) 0.0 289 Yarn breakage Good processability (Not working) during extrusion, Yarn breakage 10% 0.5 294 Good Good processability processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 1.0 291 Good Good processability processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 2.0 289 Good Good processability processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 3.0 293 Good Good processability processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage 5.0 288 Good Good processability processability during extrusion, during extrusion, Good surface Good surface without yarn without yarn breakage breakage

TABLE-US-00038 TABLE 38 TPU Succinate content (77.5%), Adipate content (0.0%), composition Glycol content (2.5%), Isocyanate content (20.0%) (100%) Processability Nano-silica Multifilament yarn content Elongation (5 denier, 36 Monofilament yarn (phr) (%) filler) (150 to 200 denier) 0.0 273 Yarn breakage Good processability (Not working) during extrusion, Yarn breakage 20% 0.5 288 Yarn breakage Good processability (Not working) during extrusion, Yarn breakage 20% 1.0 277 Yarn breakage Good processability (Not working) during extrusion, Yarn breakage 20% 2.0 279 Yarn breakage Good processability (Not working) during extrusion, Yarn breakage 30% 3.0 286 Yarn breakage Good processability (Not working) during extrusion, Yarn breakage 30% 5.0 291 Too slippery Good processability surface and during extrusion, extreme Yarn breakage 30% crystallization

[0086] As can be seen from Tables 30 to 38, the production of multifilament and monofilament yarns from a thermoplastic polyurethane having a hardness of 70A is impossible to accomplish merely with a succinate content of less than 20% due to low crystallization rate, but successfully realized with a succinate content of 20 to 75% that accelerates the crystallization rate. The succinate content of greater than 75% increases the crystallization rate extremely high, causing yarn breakage too frequently to produce monofilament or multifilament yarns. Particularly, although low-hardness (Shore 70A) thermoplastic polyurethane is used in the production of thermoplastic polyurethane yarns, it is possible not only to impart great stretch and recovery but also to realize a continuous spinning of yarns without yarn breakage during the cooling and drawing processes. Meanwhile, the elongation is increased (by about 5 to 20%) with an increase in the succinate content of the thermoplastic polyurethane.

[0087] In the present invention, nano-silica is used in combination with succinate in order to prevent yarn breakage during the cooling and drawing processes. For thermoplastic polyurethane having a hardness of 70A, the nano-silica content of 0.5 to 5.0 phr realizes a continuous spinning of yarns without yarn breakage.

[0088] Table 39 presents the conditions of the melt extrusion process in the production of the novel monofilament yarn from the thermoplastic polyurethane (succinate content 20%, refer to Table 4) having a hardness of 75D.

TABLE-US-00039 TABLE 39 Extruder ( C.) Cylinder C1 215 C2 215 C3 218 Adapter 215 Pump (G/P) 220 Dies 235 Cooling section ( C.) Cooling water 20 Drawing section Roll (G/R1) 40 (rpm) Roll (G/R2) 200 Aging section ( C.) 100 Winding section (rpm) 200

[0089] Table 40 presents the conditions of the melt extrusion process in the production of the novel monofilament yarn from the thermoplastic polyurethane (succinate content 20%, refer to Table 10) having a hardness of 60D.

TABLE-US-00040 TABLE 40 Extruder ( C.) Cylinder C1 205 C2 205 C3 210 Adapter 210 Pump (G/P) 210 Dies 230 Cooling section ( C.) Cooling water 20 Drawing section Roll (G/R1) 40 (rpm) Roll (G/R2) 200 Aging section ( C.) 100 Winding section (rpm) 200

[0090] Table 41 presents the conditions of the melt extrusion process in the production of the novel monofilament yarn from the thermoplastic polyurethane (succinate content 20%, refer to Table 17) having a hardness of 98A.

TABLE-US-00041 TABLE 41 Extruder ( C.) Cylinder C1 195 C2 195 C3 200 Adapter 200 Pump (G/P) 203 Dies 220 Cooling section ( C.) Cooling water 20 Drawing section Roll (G/R1) 40 (rpm) Roll (G/R2) 200 Aging section ( C.) 90 Winding section (rpm) 200

[0091] Table 42 presents the conditions of the melt extrusion process in the production of the novel monofilament yarn from the thermoplastic polyurethane (succinate content 30%, refer to Table 25) having a hardness of 90A.

TABLE-US-00042 TABLE 42 Extruder ( C.) Cylinder C1 180 C2 180 C3 182 Adapter 182 Pump (G/P) 182 Dies 215 Cooling section ( C.) Cooling water 20 Drawing section Roll (G/R1) 40 (rpm) Roll (G/R2) 200 Aging section ( C.) 80 Winding section (rpm) 200

[0092] Table 43 presents the conditions of the melt extrusion process in the production of the novel monofilament yarn from the thermoplastic polyurethane (succinate content 60%, refer to Table 35) having a hardness of 70A.

TABLE-US-00043 TABLE 43 Extruder ( C.) Cylinder C1 130 C2 135 C3 140 Adapter 145 Pump (G/P) 145 Dies 160 Cooling section ( C.) Cooling water 20 Drawing section Roll (G/R1) 40 (rpm) Roll (G/R2) 200 Aging section ( C.) 40 Winding section (rpm) 200

[0093] As can be seen from Tables 39 to 43, the high-hardness (Shore D type: 75D, 60D) thermoplastic polyurethane is the same in the rate of the drawing process as the low-hardness (Shore A type: 98A, 90A, 70A) thermoplastic polyurethane. More specifically, the rate is 40 rpm at the roll (G/R1) in the inlet side of the drawing section and 200 rpm (a fivefold increase) at the roll (G/R2) in the outlet side, realizing a drawing operation. In general, the high-hardness thermoplastic polyurethane (TPU) has a high crystallization rate and thus encounters no problem; but, the low-hardness thermoplastic polyurethane (TPU) has such a low crystallization rate that it is not able to maintain the defined rate (G/R1: 40 rpm, G/R2: 200 rpm) of the drawing section while the yarn is passing through the cooling and drawing sections. By using succinate and nano-silica in the low-hardness (Shore A type) thermoplastic polyurethane composition according to the present invention, it is possible to accelerate the crystallization rate and maintain the rate of the drawing section, thereby realizing a continuous spinning of yarns without yarn breakage during the cooling and drawing processes. Naturally, the use of the low-hardness thermoplastic polyurethane results in producing a thermoplastic polyurethane yarn with great stretch and recovery.

[0094] The conditions of the melt extrusion process in the production of the novel multifilament yarns are presented in Tables 44 to 49. More specifically, Table 44 presents the conditions of the melt extrusion process in the production of multifilament yarns from a thermoplastic polyurethane resin (a succinate content 0%, refer to Table 1) having a hardness of 75D; Table 45 presents the conditions of the melt extrusion process in the production of multifilament yarns from a thermoplastic polyurethane resin (succinate content 20%, refer to Table 4) having a hardness of 75D; Table 46 presents the conditions of the melt extrusion process in the production of multifilament yarns from a thermoplastic polyurethane resin (succinate content 30%, refer to Table 11) having a hardness of 60D; Table 47 presents the conditions of the melt extrusion process in the production of multifilament yarns from a thermoplastic polyurethane resin (succinate content 40%, refer to Table 19) having a hardness of 98A; Table 48 presents the conditions of the melt extrusion process in the production of multifilament yarns from a thermoplastic polyurethane resin (succinate content 50%, refer to Table 27) having a hardness of 90A; and Table 49 presents the conditions of the melt extrusion process in the production of multifilament yarns from a thermoplastic polyurethane resin (succinate content 60%, refer to Table 35) having a hardness of 70A.

TABLE-US-00044 TABLE 44 Extruder ( C.) Cylinder C1 225 C2 225 C3 230 C4 235 Filter 235 Pump (G/P) 235 Dies 235 Cooling section ( C.) Cooling air 25 Drawing section Roll (G/R1) 300 (rpm) Roll (G/R2) 900 Winding section (rpm) 1000

TABLE-US-00045 TABLE 45 Extruder ( C.) Cylinder C1 225 C2 225 C3 230 C4 235 Filter 235 Pump (G/P) 235 Dies 235 Cooling section ( C.) Cooling air 25 Drawing section Roll (G/R1) 950 (rpm) Roll (G/R2) 2850 Winding section (rpm) 3000

[0095] As can be seen from Tables 44 and 45, the thermoplastic polyurethane (TPU) with a hardness of 75D has a crystallization rate high somehow but not enough to make a multifilament yarn. The problem in association with the production of multifilament yarns from the 75D thermoplastic polyurethane (TPU) can be solved by using succinate, which accelerates the crystallization rate of the thermoplastic polyurethane (TPU) to increase the rates of the drawing section (G/R1: 950 rpm, G/R2: 2850 rpm) and the winding section (3000 rpm) and thereby to realize a continuous spinning of yarns without yarn breakage during the cooling and drawing processes.

TABLE-US-00046 TABLE 46 Extruder ( C.) Cylinder C1 205 C2 210 C3 215 C4 215 Filter 220 Pump (G/P) 225 Dies 225 Cooling section ( C.) Cooling air 25 Drawing section Roll (G/R1) 950 (rpm) Roll (G/R2) 2850 Winding section (rpm) 3000

TABLE-US-00047 TABLE 47 Extruder ( C.) Cylinder C1 195 C2 195 C3 200 C4 200 Filter 215 Pump (G/P) 220 Dies 220 Cooling section ( C.) Cooling air 25 Drawing section Roll (G/R1) 950 (rpm) Roll (G/R2) 2850 Winding section (rpm) 3000

TABLE-US-00048 TABLE 48 Extruder ( C.) Cylinder C1 180 C2 180 C3 182 C4 182 Filter 205 Pump (G/P) 215 Dies 215 Cooling section ( C.) Cooling air 25 Drawing section Roll (G/R1) 950 (rpm) Roll (G/R2) 2850 Winding section (rpm) 3000

TABLE-US-00049 TABLE 49 Extruder ( C.) Cylinder C1 130 C2 135 C3 140 C4 140 Filter 155 Pump (G/P) 155 Dies 160 Cooling section ( C.) Cooling air 25 Drawing section Roll (G/R1) 950 (rpm) Roll (G/R2) 2850 Winding section (rpm) 3000

[0096] As can be seen from Tables 45 and 49, the use of succinate in the production of multifilament yarns leads to acceleration of the crystallization rate to realize a continuous spinning of yarns without yarn breakage during the cooling and drawing processes, so the multifilament yarns can be produced without failure irrespective of the hardness of the thermoplastic polyurethane (Shore A or D).

[0097] As described above, the present invention involves using succinate as a polyol component and adding nano-silica to the thermoplastic polyurethane composition during polymerization in the production of yarns (i.e., monofilament or multifilament yarns) from low-hardness (Shore A type) thermoplastic polyurethane, to accelerate the crystallization rate in the melt extrusion process, realizing a continuous spinning of yarns without yarn breakage during the cooling and drawing processes.

[0098] Particularly, the thermoplastic polyurethane yarn and the fabric made from the thermoplastic polyurethane yarn according to the present invention can display great stretch and recovery by using low-hardness (Shore A type) thermoplastic polyurethane. In addition, the present invention can realize a continuous spinning of yarns without yarn breakage even when using high-hardness (Shore D type) thermoplastic polyurethane in the production of multifilament yarns.

[0099] The elongation increases, preferably by about 5 to 20%, with an increase in the succinate content of the thermoplastic polyurethane composition.

[0100] The present invention involves using nano-silica in combination with succinate in order to avoid yarn breakage during the cooling and drawing processes. Particularly, the nano-silica content of 0.5 to 5.0 phr results in realizing a continuous spinning of yarns without yarn breakage during the cooling and drawing processes.