Urethane-based additive and method for manufacturing discoloration-resistant polyurethane elastic fiber using same

Abstract

The present invention relates to: a urethane-based additive which is a reaction product of an organic isocyanate and a tertiary amine-containing diol having hydroxyl groups at the ends of chains and containing an n-butyl group; and a method for manufacturing a polyurethane elastic fiber using same. When the urethane-based additive of the present invention is used, it is possible to prevent deterioration in elasticity of and scum generation in polyurethane elastic fiber, and to improve discoloration resistance of polyurethane elastic fiber to ultraviolet rays and atmospheric smog.

Description

Urethane-based additive and method for manufacturing discoloration-resistant polyurethane elastic yarn using the same

[0001] The present invention relates to a urethane-based additive and a method for manufacturing a discolor-resistant polyurethane elastic yarn using the same, and more specifically, to a urethane-based additive which is a reaction product of a tertiary amine-containing diol having a hydroxyl group at the end of each chain and containing an n-butyl group and an isocyanate, and a method for manufacturing a discolor-resistant polyurethane elastic yarn using the same.

[0002] Polyurethane elastic fibers, also known as spandex or elastane, are widely used in stockings, sportswear, women's underwear, swimwear, and stretch fabrics due to their excellent elasticity and elastic recovery. Furthermore, polyurethane elastic fibers are interwoven with polyamide, polyester, and natural fibers to serve as elastic materials in various clothing applications, including bras, socks, pantyhose, and swimwear.

[0003] However, polyurethane elastic fibers are known to discolor when exposed for a long time to nitrogen dioxide, a major component of combustion gases and atmospheric smog, or to ultraviolet rays. Various methods have been attempted to solve this discoloration problem. Korean Patent Publication No. 1991-9696 discloses a discoloration-resistant spandex manufactured using a mixed additive of specific phenolic and phosphorus-based compounds. However, the said spandex has limitations in that while its discoloration resistance to heat and atmospheric smog is improved, it does not improve its discoloration resistance to ultraviolet rays.

[0004] Korean Patent Publication No. 2003-0057585 discloses a spandex comprising hindered phenolic compounds, benzofuran-one compounds, semicarbazide compounds, and polyurethane having tertiary nitrogen atoms as additives. However, the above spandex has insufficient discoloration resistance, and there is a problem that scum occurs when an excessive amount of discoloration-resistant additive is applied. Therefore, there is a need for the development of a technology that can further improve discoloration resistance against atmospheric smog and ultraviolet rays without reducing the elasticity of the polyurethane elastic yarn and without causing scum to occur.

[0005] [Prior Art Literature]

[0006] [Patent Literature]

[0007] (Patent Document 1) KR2006-0005814A

[0008] (Patent Document 2) KR2003-0057585A

[0009] The present invention aims to solve the problems of the aforementioned prior art. One objective of the present invention is to provide a urethane-based additive that helps polyurethane elastic yarns maintain excellent discoloration resistance even when exposed to the atmosphere for a long time, without side effects such as reduced elasticity and scum formation.

[0010] Another objective of the present invention is to provide a method for manufacturing a polyurethane elastic fiber with excellent discoloration resistance against atmospheric smog and ultraviolet rays.

[0011] One aspect of the present invention for solving the above-mentioned problem is,

[0012] The present invention relates to a urethane-based additive that is the reaction product of an organic isocyanate and a tertiary amine-containing diol having a hydroxyl group at the end of each chain of Chemical Formula 1 below and containing an n-butyl group.

[0013] [Chemical Formula 1]

[0014]

[0015] In the above formula, R1 and R2 are the same or different from each other and are methylene or polymethylene having 1 to 30 carbon atoms.

[0016] The above urethane-based additive may have a mixing molar ratio of 1:1 to 1:2 with an organic isocyanate and a tertiary amine-containing diol having a hydroxyl group at the end of each chain and containing an n-butyl group.

[0017] Another aspect of the present invention for solving the above-mentioned problem is,

[0018] A step of preparing a polyurethane spinning solution by reacting an organic diisocyanate and a polyol to produce a polyurethane prepolymer, dissolving the polyurethane prepolymer in an organic solvent, and then reacting it with a chain extender and a chain terminater; and

[0019] The present invention relates to a method for manufacturing a color-resistant polyurethane elastic fiber comprising the step of spinning a spinning solution prepared by adding a urethane-based additive, which is a reaction product of an organic isocyanate and a tertiary amine-containing diol having a hydroxyl group at the end of each chain of the following chemical formula 1 and containing an n-butyl group, to the above-mentioned polyurethane spinning solution.

[0020] [Chemical Formula 1]

[0021]

[0022] In the above formula, R1 and R2 are the same or different from each other and are methylene or polymethylene having 1 to 30 carbon atoms.

[0023] The above organic diisocyanate may be selected from the group consisting of 4,4-diphenylmethane diisocyanate, toluene diisocyanate, 1,6-hexamethylene diisocyanate, isophorone diisocyanate, 4,4'-methylene-dicyclohexyl diisocyanate, butylene diisocyanate, and hydrogenated P,P-methylene diisocyanate.

[0024] The above urethane-based additive can be added to a polyurethane spinning solution in the form of a urethane-based additive solution prepared by mixing and reacting a diisocyanate compound, a tertiary amine-containing diol compound having a hydroxyl group at the end of each chain of Formula 1 and containing an n-butyl group, a catalyst, and a solvent.

[0025] Bismuth catalyst, tin catalyst, nickel catalyst, cobalt catalyst, or copper catalyst may be used as the above catalyst.

[0026] In the above urethane-based additive, the mixing molar ratio of the organic isocyanate and the tertiary amine-containing diol having a hydroxyl group at the end of each chain and containing an n-butyl group can be 1:1 to 1:2.

[0027] Another aspect of the present invention for solving the above-described problem relates to a polyurethane elastic fiber manufactured by the above-described method.

[0028] The above polyurethane elastic fiber may contain the above urethane-based additive in an amount of 0.05 to 10.0 wt%.

[0029] When the urethane-based additive of the present invention is used in the manufacture of polyurethane elastic fibers, there are no side effects such as a decrease in elasticity and scum formation of the polyurethane elastic yarn, and discoloration caused by ultraviolet rays, atmospheric smog, or heat can be prevented.

[0030] The polyurethane elastic fiber of the present invention exhibits excellent resistance to discoloration against ultraviolet rays, NOx, and atmospheric smog, and has superior stability, making it suitable for high-end clothing.

[0031] The present invention will be described in more detail below. However, in describing the preferred embodiments of the present invention in detail, specific descriptions of related known functions or configurations are omitted if it is determined that such detailed descriptions may unnecessarily obscure the essence of the present invention.

[0032] In this specification, the term "fiber" may be a single filament or multiple filaments and may be used interchangeably with "yarn."

[0033] As used herein, the term "polyurethane elastic fiber" means "an elastomer fiber in which the fiber-forming material is a long-chain synthetic polymer composed of at least 85% segmented polyurethane." Polyurethaneurea elastic yarn (Spandex) is an example of a polyurethane elastic fiber. In this specification, the terms "polyurethaneurea elastic yarn," "polyurethane elastic fiber," and "polyurethane elastic yarn" are used interchangeably.

[0034] In this specification, the term "polymerization" includes the term "copolymerization" in its meaning unless otherwise indicated.

[0035] The term “solution-spinning” as used herein includes the manufacture of fibers from a solution, which may be a wet-spinning or dry-spinning process.

[0036] Furthermore, throughout the specification, the term 'comprising' a component means that, unless specifically stated otherwise, it does not exclude other components but rather allows for the inclusion of additional components.

[0037] One aspect of the present invention relates to a urethane-based additive which is a reaction product of an organic isocyanate and a tertiary amine-containing diol having a hydroxyl group at the end of each chain of the following chemical formula 1 and containing an n-butyl group.

[0038] [Chemical Formula 1]

[0039]

[0040] In the above formula, R1 and R2 are the same or different from each other and are methylene or polymethylene having 1 to 30 carbon atoms.

[0041] The above urethane-based additive can be prepared by mixing an organic isocyanate compound, a tertiary amine-containing diol compound having a hydroxyl group at the end of each chain of Formula 1 and containing an n-butyl group, a catalyst such as a bismuth-based catalyst, and a solvent to perform a urethane reaction.

[0042] Non-limiting examples of the above organic isocyanate compounds include one or more of 2,4-diphenylmethane diisocyanate, 4,4-diphenylmethane diisocyanate, toluene diisocyanate, 1,6-hexamethylene diisocyanate, isophorone diisocyanate, 4,4'-methylene-dicyclohexyl diisocyanate, butylene diisocyanate, and hydrogenated P,P-methylene diisocyanate.

[0043] As the above catalyst, any commonly used urethane catalyst can be used, but examples include catalysts such as bismuth, tin, iron, antimony, uranium, cadmium, cobalt, thorium, aluminum, zinc, nickel, cerium, molybdenum, vanadium, copper, manganese, zirconium, and calcium.

[0044] Non-limiting examples of catalysts usable in the present invention may include, as organometallic compounds, organotin compounds such as tin acetate, tin octylate, tin oleate, tin laurylate, dibutyltin diacetate, dimethyltin dilaurate, dibutyltin dilaurate, dibutyltin dimercaptide, dibutyltin maleate, dibutyltin dilaurate, dibutyltin dineodecanoate, dioctyltin dimercaptide, dioctyltin dilaurate, dibutyltin dichloride, etc., organotin compounds such as nickel naphthenate, etc., organotin compounds such as cobalt naphthenate, etc., organotin compounds such as copper octene, etc., and organotin compounds such as bismuth octylate, bismuth neodecanoate, etc.

[0045] As the above solvent, N,N-dimethylacetamide (DMAc), N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), or N-methylpyrrolidinone (NMP) may be used.

[0046] Examples of tertiary amine-containing diol compounds having a hydroxyl group at the end of each chain of Chemical Formula 1 and containing an n-butyl group include n-butyldiethanolamine (BDEA), n-butyldimethanolamine, n-butyldipropanolamine, n-butyldibutanolamine, n-butyldipentanolamine, n-butyldihexanolamine, n-butyldiheptanolamine, etc.

[0047] Another aspect of the present invention relates to a method for manufacturing a polyurethane elastic fiber, comprising spinning a polyurethane spinning solution containing the urethane-based additive. There are no particular limitations on the method used to obtain a polyurethane elastic fiber containing the urethane-based additive in the present invention, and any method for manufacturing a polyurethane elastic fiber by spinning a spinning solution containing polyurethane and a urethane-based additive may be used.

[0048] In the present invention, to improve the discoloration resistance of polyurethane elastic fibers, a urethane-based additive having a tertiary amine-containing diol and an organic diisocyanate having a hydroxyl group at the end of each chain and containing an n-butyl group is used as an additive.

[0049] In the method of the present invention, a polyurethane prepolymer is prepared by first reacting an organic diisocyanate and a polyol, and then a polyurethane spinning solution is prepared by dissolving the polyurethane prepolymer in an organic solvent and reacting it with a chain extender and a chain terminater. Subsequently, a urethane-based additive, which is a reaction product of an organic isocyanate and a tertiary amine-containing diol having a hydroxyl group at the end of each chain of Chemical Formula 1 below and containing an n-butyl group, is added to the polyurethane spinning solution based on the polyurethane elastic fiber, and the additive is spun to produce a color-resistant polyurethane elastic fiber.

[0050] [Chemical Formula 1]

[0051]

[0052] In the above formula, R1 and R2 are the same or different from each other and are methylene or polymethylene having 1 to 30 carbon atoms.

[0053] In the present invention, the amount of urethane-based additive in the polyurethane elastic fiber is preferably within the range of 0.05 weight% or more and 10 weight% or less. If the amount of urethane-based additive is less than 0.05 weight%, a sufficient anti-discoloration effect cannot be obtained, and conversely, if the amount of urethane-based additive exceeds 10.0 weight%, problems such as a decrease in strength and scum formation may occur in the polyurethane elastic fiber used as the substrate. In the present invention, the content of urethane-based additive in the polyurethane elastic fiber can be confirmed and quantified using various analytical methods such as 1H-NMR, elemental analysis, ion chromatography, and GPC.

[0054] The above organic diisocyanate may be selected from the group consisting of 4,4-diphenylmethane diisocyanate, toluene diisocyanate, 1,6-hexamethylene diisocyanate, isophorone diisocyanate, 4,4'-methylene-dicyclohexyl diisocyanate, butylene diisocyanate, and hydrogenated P,P-methylene diisocyanate.

[0055] The above urethane-based additive may be added to a polyurethane spinning solution in the form of a urethane-based additive solution prepared by mixing and reacting a diisocyanate compound, a tertiary amine-containing diol compound having a hydroxyl group at the end of each chain of Formula 1 and containing an n-butyl group, a catalyst, and a solvent. In solution polymerization, an organic isocyanate component and a tertiary amine-containing diol compound component are added to an organic solvent and reacted at a reaction temperature of 50 to 120°C, more preferably 50 to 100°C, for about 0.5 to 15 hours.

[0056] Polyether diols, polyester diols, or polycarbonate diols are preferred as the polyols used as structural units constituting the polyurethane. Polyether diols are particularly preferred in terms of imparting flexibility and elasticity to the fibers.

[0057] Preferred examples of polyether polyols include polyethylene oxide, polyethylene glycol, polyethylene glycol derivatives, polypropylene glycol, modified PTMG (3M-PTMG), which is a copolymer of polytetramethylene ether glycol (PTMG), tetrahydrofuran (THF), and 3-methyltetrahydrofuran, modified PTMG and THF, which is a copolymer of THF and 2,3-dimethyl THF, and random copolymers in which ethylene oxide and / or propylene oxide are irregularly arranged. One or more of these polyether diols may be used by mixing or copolymerizing together.

[0058] These polyols can be used alone, or two or more can be mixed together or copolymerized before use.

[0059] In terms of obtaining elasticity, strength, and heat resistance when manufactured into fibers, the number average molecular weight of the polyol is preferably 1,000 to 8,000, more preferably 1,800 to 6,000. When a polyol having a molecular weight in this range is used, an elastic fiber having excellent elasticity, strength, elastic recovery, and heat resistance can be easily obtained. The molecular weight is measured by GPC and converted to polystyrene.

[0060] As the diisocyanate used in the manufacture of the polyurethane elastic yarn of the present invention, 4,4-diphenylmethane diisocyanate, toluene diisocyanate, 1,6-hexamethylene diisocyanate, isophorone diisocyanate, 4,4'-methylene-dicyclohexyl diisocyanate, butylene diisocyanate, or hydrogenated P,P-methylene diisocyanate may be used.

[0061] Polyurethane can be synthesized from the aforementioned raw materials in solvents such as N,N-dimethylacetamide (DMAc), N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), and N-methylpyrrolidinone (NMP).

[0062] In the present invention, one or more diol or diamine chain extenders may be used as chain extenders.

[0063] The diamine chain extenders usable in the present invention may include one or more selected from the group consisting of ethylenediamine, 1,2-diaminopropane, 1,3-diaminopropane, 1,4-diaminobutane, 2,3-diaminobutane, 1,5-diaminopentane, 1,6-hexamethylenediamine, 1,4-cyclohexanediamine, and combinations thereof, but are not necessarily limited to these.

[0064] Examples of diol chain extenders usable in the present invention include ethylene glycol, 1,3-propanediol, 1,2-propylene glycol, 3-methyl-1,5-pentanediol, 2,2-dimethyl-1,3-trimethylenediol, 2,2,4-trimethyl-1,5-pentanediol, 2-methyl-2-ethyl-1,3-propanediol, 1,4-bis(hydroxyethoxy)benzene and 1,4-butanediol and mixtures thereof, but are not necessarily limited to these.

[0065] For controlling the molecular weight of polyurethane, one or more amines having a single functional group may be used, selected from the group consisting of, for example, diethylamine, monoethanolamine, cyclohexylamine, and dimethylamine, but are not necessarily limited to these.

[0066] The polyurethane particularly suitable for the present invention is synthesized using PTMG as a polyol having a number average molecular weight of 1,800 or more and 6,000 or less, MDI as a diisocyanate, and at least one type selected from ethylenediamine, 1,2-propanediamine, 1,3-propanediamine, and hexamethylenediamine as a chain extender.

[0067] Polyurethane elastic yarns may contain additives such as stabilizers and pigments, but such additives should not impair the advantages of the present invention. Such additives include benzotriazole-based stabilizers, UV absorbers, other light-reducing agents, antioxidants, matting agents, anti-sticking agents, dyes and dye promoters, lubricants (e.g., mineral oil and silicone oil), deodorizers, and antistatic agents. Other examples of additives include polymers of bis(4-isocyanatocyclohexyl)methane and 3-t-butyl3-aza-1,5-pentanediol), titanium oxide, zinc oxide, magnesium stearate, barium sulfate, mixtures of hydrotalcite, huntite and hydromagnesite, and fungicides containing silver, zinc, or compounds thereof.

[0068] There are no specific restrictions on the method of adding these other additives, and any conventional method, such as appropriate mixing, may be used. The additives may be mixed into the spinning solution at any stage after the polyurethane is formed and before the spinning solution is spun into fibers. As a representative method, blending using a static mixer or a stirring method after adding to the spinning solution may preferably be used.

[0069] When forming polyurethane elastic fibers by spinning polyurethane obtained by a solution polymerization method, the spinning method is not particularly limited, and known methods such as dry spinning and wet spinning can be appropriately used. However, considering productivity, dry spinning is preferred in that stable spinning is possible for all finenesses from thin to thick threads.

[0070] Another aspect of the present invention relates to a polyurethane elastic fiber manufactured by the method described above.

[0071] The polyurethane elastic fiber produced by the method of the present invention can be suitably used in, for example, clothing such as innerwear, stockings, socks, sportswear, swimwear, and fashion clothing; clothing materials such as elastic tapes and strings; vehicle interior materials such as vehicle seats; and sanitary products such as disposable diapers.

[0072] The present invention will be described in more detail below with reference to examples. However, the following examples are intended to illustrate embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Furthermore, in the examples, "parts" and "%" refer to weight standards unless otherwise specified.

[0073] Examples

[0074] Preparation Example 1

[0075] A urethane-based additive solution (A) was prepared by mixing 37.05 g of n-butyldiethanolamine, 52.42 g of 4,4'-methylene-dicyclohexyl diisocyanate, 100 ppm of bismuth-based catalyst, and 166.15 g of dimethylacetamide and reacting at 60°C for 3 hours.

[0076]

[0077] Preparation Example 2

[0078] A urethane-based additive solution (B) was prepared in the same manner as in Preparation Example 1, except that 51.26 g of isocyanate in which 2,4'-methylene-diphenyl diisocyanate and 4,4'-methylene-diphenyl diisocyanate were mixed in a 5:5 ratio was used as the diisocyanate.

[0079]

[0080] Preparation Example 3

[0081] A urethane-based additive solution (C) was prepared in the same manner as in Preparation Example 1, except that 44.46 g of isophorone diisocyanate was used as the diisocyanate.

[0082]

[0083] Preparation Example 4

[0084] A urethane-based additive solution (D) was prepared in the same manner as in Preparation Example 1, except that 33.64 g of 1,6-hexamethylene diisocyanate was used as the diisocyanate.

[0085]

[0086] Preparation Example 5

[0087] A urethane-based additive solution (E) was prepared in the same manner as in Preparation Example 1, except that 37.09 g of tert-butyldiethanolamine was used as the tertiary amine.

[0088]

[0089] Preparation Example 6

[0090] A urethane-based additive solution (F) was prepared in the same manner as in Preparation Example 1, except that 27.41 g of n-methyldiethanolamine was used as the tertiary amine.

[0091]

[0092] Preparation Example 7

[0093] 525 g of (n,n-diethyl-2-aminoethyl methacrylate), 4.5 g of AIBN as an initiator, and 975 g of dimethylacetamide were mixed and reacted at 85°C for 3 hours to prepare a poly(n,n-diethyl-2-aminoethyl methacrylate) acrylic additive solution (G).

[0094]

[0095] Example 1

[0096] A primary polymer was prepared by mixing polytetramethylene ether glycol with a molecular weight of 1800 and a capping ratio (CR) of 1.61 with 4,4'-diphenylmethane diisocyanate. Ethylenediamine was used as a chain extender and diethylamine as a chain terminater. The ratio of the chain extender to the chain terminater was set to 7:1, and the mixture of the chain extender and chain terminater was prepared at a total concentration of 7 mol%, with dimethylacetamide used as the solvent. Specifically, 35.2 g of polytetramethylene ether glycol with a molecular weight of 1800 and 7.8 g of methylene diisocyanate were reacted under a nitrogen stream at 90°C for 180 minutes while stirring to prepare a polyurethaneurea prepolymer having isocyanates at both ends.

[0097] After cooling the above prepolymer to room temperature, 55.3g of dimethylacetamide was added to 43.1g of the prepolymer to obtain a polyurethaneurea prepolymer solution. Subsequently, 43.7g of ethylenediamine and 4.3g of diethylamine were dissolved in 1860g of dimethylacetamide and added to the above prepolymer solution at 10℃ or below to obtain a polyurethaneurea solution.

[0098] A mixed polyurethaneurea spinning solution was obtained by adding 1.0 wt% of ethylenebis(oxyethylene)bis-(3-(5-t-butyl-4-hydroxy-m-toyl)-propionate), 0.1 wt% of titanium dioxide, and 0.1 wt% of a urethane-based additive solution (A) as additives relative to the solid content of the above polymer. Polyurethane elastic fibers of 40 denier / 3 filaments were produced by dry spinning of the spinning solution obtained in this way at a speed of 700 m / min.

[0099]

[0100] Example 2

[0101] Polyurethane elastic fibers were prepared in the same manner as in Example 1, except that the content of the urethane-based additive solution (A) was changed to 2.0 wt%.

[0102]

[0103] Example 3

[0104] Polyurethane elastic fibers were prepared in the same manner as in Example 1, except that 0.1 wt% of a urethane-based additive solution (B) was added.

[0105]

[0106] Example 4

[0107] Polyurethane elastic fibers were prepared by carrying out the same procedure as in Example 1, except that 0.1 wt% of a urethane-based additive solution (C) was added.

[0108]

[0109] Example 5

[0110] Polyurethane elastic fibers were prepared in the same manner as in Example 1, except that 0.1 wt% of a urethane-based additive solution (D) was added.

[0111]

[0112] Comparative Example 1

[0113] Polyurethane elastic fibers were prepared in the same manner as in Example 1, except that 2.0 wt% of a urethane-based additive solution (E) was added.

[0114]

[0115] Comparative Example 2

[0116] Polyurethane elastic fibers were prepared in the same manner as in Example 1, except that 2.0 wt% of an acrylic additive solution (F) was added.

[0117]

[0118] Comparative Example 3

[0119] Polyurethane elastic fibers were prepared in the same manner as in Example 1, except that 2.0 wt% of a urethane-based additive solution (G) was added.

[0120]

[0121] Comparative Example 4

[0122] Polyurethane elastic fibers were prepared by carrying out the same procedure as in Example 1, except that no urethane-based additive solution was added.

[0123]

[0124] Test example

[0125] The physical properties of the polyurethane elastic fibers prepared in Examples 1-5 and Comparative Examples 1-4 were measured by the following method, and the results are shown in Table 1 below.

[0126] Discoloration resistance

[0127] The polyurethane elastic fibers prepared in Examples 1-5 and Comparative Examples 1-4 were woven into a fabric form, and specimens measuring 3 cm in width and 10 cm in length were prepared. Each specimen was immersed in a bath of 1 g / L of scouring agent and 1 g / L of NaOH at 80°C for 5 minutes, and then air-dried for 12 hours.

[0128] (1) UV lamp treatment conditions: After being left under a UV-B lamp for 24 hours, the resistance to discoloration against ultraviolet rays was evaluated.

[0129] (2) NOx gas treatment conditions: Sodium nitrate and phosphoric acid were used to evaluate the discoloration resistance of the NOx gas after being left for 24 hours in the presence of NOx gas. The discoloration resistance was measured using BYK Gardner’s Color-view™, and the difference in discoloration resistance (color difference) was expressed by measuring βb = b2 - b1, where b1 was the yellow value before treatment and b2 was the yellow value after treatment. A lower βb value indicates superior discoloration resistance.

[0130] Immediate recovery

[0131] Using an automatic tensile strength measuring device (MEL machine, Textechon), 20 strands of polyurethane elastic fiber samples with a length of 10 cm were used, and the ratio (%) of the deformed length to the initial length was measured after 5 repetitions of 300% at a tensile speed of 100 cm / min.

[0132] Presence or absence of scum

[0133] In each test, 10 packages of dry-spun polyurethane elastic fibers obtained immediately after spinning were wound onto a miniature warping machine for 1500 km at a thread speed of 300 m / min under an atmosphere of 65% RH at 25°C. At this time, the presence or absence of scum was evaluated according to the following criteria based on the amount of scum accumulated in the comb guide of the miniature warping machine.

[0134] (O): Evaluated as scum formation when the yield of scum is 0.01 g or more.

[0135] (X): When the yield of scum is 0.01 g or less, it is evaluated as no scum formed.

[0136] Classification Urethane-based Additive Urethane-based Additive Content Discoloration Resistance (βb) Presence / Absence of Scum Formation Elastic Recovery Rate (%) After UV Treatment After NOx Gas Treatment Example 1 Polymer A 0.1% 12.1 13.5 X 25 Example 2 Polymer A 2.0% 11.1 10.7 X 25 Example 3 Polymer B 0.1% 13.1 12.1 X 26 Example 4 Polymer C 0.1% 12.8 12.5 X 25 Example 5 Polymer D 0.1% 11.6 12.8 X 24 Comparative Example 1 Polymer E 2.0% 11.9 11.8 X 32 Comparative Example 2 Polymer F 2.0% 12.6 15.7 O 28 Comparative Example 3 Polymer G 2.0% 12.6 21.4 O 28 Comparative Example 4 Unadded 0.0% 26.6 30.4 X 27

[0137] As can be seen from Table 1 above, it can be confirmed that the polyurethane elastic yarns produced in Examples 1-5 have excellent discoloration resistance without any decrease in elasticity or scum formation.

[0138] Although the present invention has been described in detail above with reference to preferred embodiments, the invention is not limited thereto. The above embodiments may be modified or changed without departing from the spirit and scope of the invention, and those skilled in the art will understand that such modifications and changes are also included in the present invention.

Claims

1. A urethane-based additive that is the reaction product of an organic isocyanate and a tertiary amine-containing diol having a hydroxyl group at the end of each chain of Chemical Formula 1 below and containing an n-butyl group. [Chemical Formula 1] In the above formula, R1 and R2 are the same or different from each other and are methylene or polymethylene having 1 to 30 carbon atoms.

2. A urethane-based additive according to claim 1, wherein the organic isocyanate is one or more selected from the group consisting of 2,4-diphenylmethane diisocyanate, 4,4-diphenylmethane diisocyanate, toluene diisocyanate, 1,6-hexamethylene diisocyanate, isophorone diisocyanate, 4,4'-methylene-dicyclohexyl diisocyanate, butylene diisocyanate, and hydrogenated P,P-methylene diisocyanate.

3. The urethane-based additive according to claim 1, characterized in that the mixing molar ratio of the organic isocyanate with the tertiary amine-containing diol having a hydroxyl group at the end of each chain and containing an n-butyl group is 1:1 to 1:

2.

4. A step of preparing a polyurethane spinning solution by reacting an organic diisocyanate and a polyol to produce a polyurethane prepolymer, dissolving the polyurethane prepolymer in an organic solvent, and then reacting it with a chain extender and a chain terminater; A method for manufacturing a polyurethane elastic fiber comprising the step of spinning a spinning solution prepared by adding a urethane-based additive, which is a reaction product of an organic isocyanate and a tertiary amine-containing diol having a hydroxyl group at the end of each chain of Chemical Formula 1 and containing an n-butyl group, to the above-mentioned polyurethane spinning solution. [Chemical Formula 1] In the above formula, R1 and R2 are the same or different from each other and are methylene or polymethylene having 1 to 30 carbon atoms.

5. A method for manufacturing a polyurethane elastic fiber according to claim 4, wherein the organic diisocyanate is selected from the group consisting of 4,4-diphenylmethane diisocyanate, toluene diisocyanate, 1,6-hexamethylene diisocyanate, isophorone diisocyanate, 4,4'-methylene-dicyclohexyl diisocyanate, butylene diisocyanate, and hydrogenated P,P-methylene diisocyanate.

6. A method for manufacturing a polyurethane elastic fiber according to claim 4, wherein the urethane-based additive is added to a polyurethane spinning solution in the form of a urethane-based additive solution prepared by mixing and reacting an organic isocyanate compound, a tertiary amine-containing diol compound having a hydroxyl group at the end of each chain of Formula 1 and containing an n-butyl group, a catalyst, and a solvent.

7. A method for manufacturing a polyurethane elastic fiber according to claim 6, wherein the organic isocyanate is one or more of 2,4-diphenylmethane diisocyanate, 4,4-diphenylmethane diisocyanate, toluene diisocyanate, 1,6-hexamethylene diisocyanate, isophorone diisocyanate, 4,4'-methylene-dicyclohexyl diisocyanate, butylene diisocyanate, and hydrogenated P,P-methylene diisocyanate.

8. A method for manufacturing a polyurethane elastic fiber according to claim 6, characterized in that the catalyst is a bismuth catalyst, a tin catalyst, a nickel catalyst, a cobalt catalyst, or a copper catalyst.

9. A method for manufacturing a polyurethane elastic fiber according to claim 6, wherein the solvent is N,N-dimethylacetamide (DMAc), N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), or N-methylpyrrolidinone (NMP).

10. A method for manufacturing a polyurethane elastic fiber according to claim 4, characterized in that the mixing molar ratio of the organic isocyanate in the urethane-based additive and the tertiary amine-containing diol having a hydroxyl group at the end of each chain and containing an n-butyl group is 1:1 to 1:

2.

11. A method for manufacturing a polyurethane elastic fiber according to claim 4, characterized in that the polyurethane elastic fiber contains 0.05 to 10.0 wt% of the urethane-based additive.

12. Polyurethane elastic fiber to which a urethane-based additive of any one of paragraphs 1 to 3 has been applied.

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