KR101238495B1 - Discoloration-resistant and chlorine-resistant Spandex Fiber and Preparation Method thereof - Google Patents

Abstract

The present invention includes a spandex fiber having improved chlorine resistance and discoloration resistance, including a hydrotalcite and a symmetric di hindered hydroxyphenyl compound, an asymmetric di hindered hydroxyphenyl compound, and a semicarbazide compound. As the spandex fiber of the present invention has excellent chlorine resistance, it can be used more effectively in sports leisure clothing such as swimwear.

Description

Spandex fiber with improved chlorine resistance and discoloration resistance and its manufacturing method {Discoloration-resistant and chlorine-resistant Spandex Fiber and Preparation Method}

The present invention relates to a spandex fiber excellent in chlorine resistance and discoloration resistance and a method for producing the same, and more particularly, a symmetrical di-hindered hydroxyphenyl compound, an asymmetric di-hindered hydroxyphenyl compound, and a semicarbazide-based compound. The present invention relates to a spandex fiber containing a compound and an inorganic chlorine agent and having improved chlorine resistance and discoloration resistance while maintaining conventional physical properties.

Spandex, which is a typical polyurethane elastic fiber, maintains high rubber elasticity and is excellent in physical properties such as tensile stress and recoverability. Therefore, spandex is widely used in underwear, socks, sports and leisure clothing. However, polyurethane, which is the main component of spandex, exhibits a significant decrease in physical properties in chlorine bleaching. Swimsuits made from alternating spandex and polyamide are strong when used in swimming pools with chlorine content of 0.5 to 3.5 ppm or more. Deteriorates the physical properties of spandex.

Efforts have been made to improve the resistance of spandex fibers to such chlorine deterioration. As a chlorine resistant agent used in spandex, US Patent No. 4,340,527, zinc oxide, US Patent No. 5,626,960, a mixture of huntite and hydromagnesite, and Korean Patent Publication No. 92-03250, calcium carbonate and barium carbonate, 6-81215 is treated with MgO / ZnO solid solution, Japanese Patent Application Laid-Open No. 59-133248 with magnesium oxide, magnesium hydroxide or hydrotalcite, and Japanese Patent Application Laid-open No. 3-292364 with higher fatty acid and silane coupling agents. Hydrotalcites are disclosed, respectively.

In addition, in order to improve the chlorine resistance of spandex fibers, phenolic compounds may be used as additives. For example, Japanese Patent Publication No. 50-004387 discloses a phenolic additive as a stabilizer for spandex, and US Pat. Techniques for improving the chlorine resistance and discoloration by combustion by mixing additives and organic additives are disclosed.

The present invention has been invented to solve the above problems, the present invention contains a symmetric di hindered hydroxy phenolic compound, an asymmetric di hindered hydroxy phenolic compound and a semicarbazide-based compound and an inorganic chlorine agent The purpose of the present invention is to provide a spandex fiber having improved chlorine resistance and discoloration resistance and a method of manufacturing the polyurethane polymer while maintaining the conventional physical properties.

Spandex fiber with improved chlorine resistance and discoloration resistance according to the present invention is 0.1 to 10% by weight of inorganic chlorine resistant agent, 0.1 to 5% by weight of symmetrical di-hindered hydroxyphenyl-based compound, asymmetrical di-hindered based on polyurethane polymer 0.1 to 5% by weight of the hydroxyphenyl-based compound and 0.1 to 5% by weight of the semicarbazide-based compound.

According to the present invention, a method for preparing spandex fiber having improved chlorine resistance and discoloration resistance is obtained by reacting an organic diisocyanate and diol to prepare a polyurethane precursor, and then dissolving the polyurethane precursor in an organic solvent. Preparing a polyurethane solution prepared by reacting; And 0.1 to 10% by weight of an inorganic chlorine agent based on the polyurethane polymer in the polyurethane solution, and 0.1 to 5% by weight of a symmetric di-hindered hydroxyphenyl-based compound and an asymmetric di-hindered hydroxyphenyl-based chemical 0.1 to 5% by weight and semicarbazide-based compound is characterized in that it comprises the step of spinning by adding 0.1 to 5% by weight.

According to the present invention, chlorine resistance is improved and discoloration resistance is improved by introducing a symmetric di hindered hydroxyphenyl compound, an asymmetric di hindered hydroxyphenyl compound, and a semicarbazide compound. Since the spandex of the present invention has excellent chlorine resistance, it can be used more effectively in sports leisure clothing such as swimwear.

The present invention is characterized by adding an inorganic chlorine agent that has been added to improve the chlorine resistance as it is, and additionally an organic additive having a synergistic effect in order to sustain excellent chlorine resistance. The present invention is mixed with a semi-carbazide-based compound having a radical scavenger function in a symmetrical di-hind hindered hydroxyphenyl-based compound and an asymmetric di-hindered hydroxyphenyl-based compound as an additive for improving chlorine resistance. In addition to the improvement, the main content is to improve the discoloration resistance at the same time.

In the present invention, the spandex fiber contains an inorganic chlorine agent, a symmetric di hindered hydroxyphenyl compound, an asymmetric di hindered hydroxyphenyl compound and a semicarbazide compound.

Specific examples of the symmetric dihindered hydroxyphenyl compound are as follows.

Tetrakis [methylene-2- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] methane

In addition, the symmetrical di-hindered hydroxyphenyl-based compound is not particularly limited, but examples thereof include tetrakis [methylene-2- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate].

Methane or tris (3,5-di-tert-butyl-4-hydroxy-5-methylphenyl) propionate, 3,3 ', 3 ", 5,5', 5" -hexa-tetra-butyl- a, a ', a ”-(mesitylene-2,4,6-tril) tri-p-cresol, hexamethylenebis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) Propionate, 1,2-bis (3,5-di-tert-butyl-4-hydroxyhydroxyanoyl) hydrazine, N, N'-hexamethylenebis (3,5-di-tertary- Butyl-4-hydroxyhydrocinamide), 2,4-di-tertiary-butylphenyl-4'-hydroxy-3 ', and 5'-di-tertiary-butyl benzoate Or more species.

 Specific examples of the asymmetric di hindered hydroxyphenyl compound are as follows.

Triethylene glycol-bis-3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionate

 In addition, 1,3,5-tris (2,6-dimethyl-3-hydroxy-4- tert-butylbenzyl) isocyanurate is mentioned.

 Specific examples of the semicarbazide compound are as follows.

1,1,1 ', 1'-tetramethyl-4,4' (methylene-di-p-phenylene) dicemicarbazide

In addition, 1, 6- hexamethylene bis (N'N- dimethyl semicarbazide) and a biurettri-tri (hexamethylene-N, N- dimethyl semicarbazide) are mentioned as a semicarbazide type compound. Of these, the most suitable for the application of spandex is 1,1,1 ', 1'-tetramethyl-4,4' (methylene-di-p-phenylene) disemicarbazide. Semicarbazide-based compounds impart discoloration resistance to the spandex with respect to atmospheric smog.

On the other hand, chlorine-resistant inorganic chlorine agents are hydrotalcite, hydromagnesite, mixed minerals of huntite and hydromagnesite, zinc oxide and magnesium oxide, which have the property of trapping halogen, which is very effective in harming chlorine.

[Formula 1]

^{_{M 2+ x Al 2 (OH)}} y (A n-) z O k · mH 2 O

[Wherein, M ^{2 +} is Mg ^{2 +,} Ca ^{2 +} or Zn ^{2 +} a, A ^{n -} is an anion having a valence of n, x, y are two or more positive values, Z is a positive value equal to or less than 3 and, k is a positive number of 0 or more than 3, m is 0 or a positive number, a ^{n -} is ^{OH -, F -, Cl -} , Br -, NO 3 -, SO 4 2 -, CH 3 COO -, _{^{CO 3 2 -, HPO 4 2-}} , oxalate ion, salicylate ion, silicate ion or Im.

Non-limiting examples of the hydrotalcite compound of Formula 1 include Mg _4.5 Al ₂ (OH) ₁₃ CO ₃ · 3.5H ₂ O, Mg ₆ Al ₂ (OH) ₁₆ CO ₃ · 5H ₂ O, Mg ₈ Al ₂ ( OH) ₂₀ CO ₃ · 6H ₂ O, Mg ₄ Al ₂ (OH) ₁₂ CO ₃ · 3H ₂ O, Mg _4.5 Al ₂ (OH) ₁₃ CO ₃ , Mg ₆ Al ₂ (OH) ₁₆ CO ₃ , Mg ₈ Al ₂ (OH) ₂₀ CO ₃ , Mg ₄ Al ₂ (OH) ₂₀ CO ₃ , Mg _4.5 Al ₂ (OH) ₁₃ (CO ₃ ) _0.6 O _0.4 , Mg ₆ Al ₂ (OH) ₁₆ (CO ₃ ) _0.7 O _0.3 , Mg _4.5 Al ₂ (OH) _12.2 (CO ₃ ) _0.8 O _0.6 , Mg ₄ Al ₂ (OH) ₁₂ (CO ₃ ) _0.6 O _0.4, and any mixtures thereof.

Hydrotalcite has a feature of absorbing moisture, and when it is added to a polyurethane polymer without coating, gel generation and aggregation may occur and cause trimming in the spinning process. Hydrotalcite can be coated and used to prevent water absorption and improve dispersibility of hydrotalcite to improve the release pressure and trimming during the spinning process. Even in the case of using uncoated hydrotalcite, when the sand grinding or milling is performed, the same radioactivity can be obtained as in the case of using the coated hydrotalcite.

Examples of the hydrotalcite coating agent include aliphatic alcohols, fatty acids, fatty acid salts, aliphatic esters, phosphate esters, styrene / maleic anhydride copolymers and derivatives thereof, silane coupling agents, titanate coupling agents, polyorganosiloxanes, Polyorganohydrogensiloxane, melamine type compounds, and the like. The coating agent is preferably a fatty acid, fatty acid salt and / or melamine based compound. In the case of fatty acids or fatty acid salts, the effect of the coating is superior to other coating materials. In the coating of hydrotalcite, an appropriate amount of coating agent is added to a solvent such as water, alcohol, ether, dioxane, and the like so that the amount of the coating agent is 0.1 to 10% by weight based on the weight of hydrotalcite, and then uncoated hydrotalcite is added. The temperature is increased and stirred for 20 minutes to 2 hours at 60 to 180 ° C. (using a high pressure reactor if necessary), followed by filtering and drying after stirring. Another method is a method in which the coating agent is heated and dissolved without solvent, and then mixed with hydrotalcite at a high speed to coat the coating agent.

[Formula 2]

Mg ₃ Ca (CO ₃ ) ₃ (Huntite) (1)

Mg ₄ (CO ₃ ) ₄ Mg (OH) ₂ · 5H ₂ 0 (hydromagnesite) (2)

Huntite and hydromagnesite are present in the form of mixtures when present as minerals and are difficult to separate into pure huntite or pure hydromagnesite.

[Formula 3]

_{^{M 2 + x (A n -}} ) y M 2 + (OH) z · mH 2 0 ( hydro magnesite)

(Wherein, M ^{2 +} is Mg ^{2 +} or Ca ^{2 +,} A ^{n -} is CO ₃ ^{2 -,} x is 1 ~ 5, z is 0 ~ 2, m is 0 to 5.)

Hydromagnesite can also be obtained as a mineral and can also be obtained through synthesis. Examples of coatings that can be used for hydromagnesite include aliphatic alcohols, fatty acids, fatty acid salts, aliphatic esters, phosphate esters, styrene / maleic anhydride copolymers and derivatives thereof, silane coupling agents, titanate coupling agents, polyorganosiloxanes, polyors It includes, but is not necessarily limited to, one or more selected from the group consisting of ganohydrogensiloxane and melamine-based compounds. The coating agent is preferably a fatty acid, fatty acid salt and / or melamine based compound.

Polyurethane polymers used in the preparation of the spandex according to the present invention, as is known in the art, is prepared by reacting an organic diisocyanate and a polymer diol to prepare a polyurethane precursor, which is dissolved in an organic solvent and then diamine and mono Prepared by reacting with an amine. Organic diisocyanates used in the present invention include diphenylmethane-4,4'- diisocyanate, hexamethylene diisocyanate, toluene diisocyanate, butylene diisocyanate, hydrogenated diphenylmethane-4,4'- diisocyanate, and the like. have. In addition, polytetramethylene ether glycol, polypropylene glycol, polycarbonate diol, or the like may be used as the polymer diol. Diamines are used as chain extenders and include, for example, ethylenediamine, propylenediamine, hydrazine and the like. On the other hand, monoamine is used as a chain terminator, for example, diethylamine, monoethanolamine, dimethylamine, and the like.

In addition to the above components, the spandex of the present invention may further include an inorganic additive such as titanium dioxide and magnesium stearate. Titanium dioxide can be used in the range of 0.1 to 5% by weight, depending on the whiteness of the fiber. In addition, magnesium stearate may be used in the range of 0.1 to 2% by weight, which is added to improve the dissolvability of spandex.

In the present invention, the amount of the symmetrical dihindered hydroxyphenyl-based compound and the asymmetrical dihindered hydroxyphenyl-based compound is preferably 0.1 to 5% by weight relative to the polyurethane polymer, but less than 0.1% by weight improves the chlorine resistance of the spandex. It is not preferable because there is little property contributing to it, and when it exceeds 5% by weight, there is no improvement effect on excessive input and the color change of spandex is insufficient.

Semicarbazide-based compound in the present invention is 0.1 to 5% by weight compared to the polyurethane polymer. If it is less than 0.1 wt%, the discoloration improvement effect is insignificant, and if it exceeds 5 wt%, no further expression effect can be obtained.

In the present invention, the addition amount of the inorganic chlorine resistant agent is preferably 0.1 to 10% by weight compared to the polyurethane polymer, when less than 0.1% by weight is less than the property of imparting chlorine resistance to the spandex, when exceeding 10% by weight excessive inorganic It is not preferable because the content lowers the strength, elongation and modulus of spandex.

In preparing the spandex of the present invention, organic additives and inorganic chlorine resistant agents may be added to the polyurethane polymer at any convenient time. For example, the inorganic chlorine resistant agent may be added to the solution together with other additives and mixed with the polyurethane polymer during the sand grinding or milling process, and sand grinding or milling in the solvent separately from the other additives. May be mixed with the polyurethane polymer during the process. In addition, the phosphorus antioxidant may also be added during the sand grinding or milling process, may be added separately dissolved in a solvent.

In the present invention, the inorganic chlorine resistant agent may be coated or uncoated with a coating agent commonly used in the art, and the coating does not affect the discoloration resistance and the chlorine resistance of the spandex yarn.

The process of sand grinding or milling the inorganic chlorine agent is performed by mixing the inorganic chlorine agent, the solvent and a small amount of the polyurethane polymer using a conventional bead mill, and milling the particles to be smaller, or hydrotalcite or solvent. , Other additives and a small amount of polyurethane polymer may be mixed to form a slurry to mill to make the particles smaller. Here, a small amount of polyurethane polymer serves to improve the dispersibility of the inorganic chlorine agent. As a solvent, 1 or more types of dimethylacetamide, dimethylformamide, and dimethyl sulfoxide can be selected and used.

Under the above conditions, the present inventors confirmed that the hydrotalcite partially dehydrated also had no problem in the spandex manufacturing process when milling in order to reduce the particle size.

518 g of diphenylmethane-4,4′-diisocyanate and 2328 g of polytetramethylene ether glycol (molecular weight 1800) were reacted with stirring at 90 ° C. for 95 minutes in a nitrogen gas stream to prepare a polyurethane prepolymer having an isocyanate at the sock end. It was. After cooling the prepolymer to room temperature, 4269 g of dimethylacetamide was added to dissolve to obtain a polyurethane prepolymer solution.

Subsequently, 43 g of ethylenediamine and 9.1 g of diethylamine were dissolved in 1889 g of dimethylacetamide and added to the prepolymer solution at 9 ° C. or lower to obtain a polyurethane solution. 1% by weight of poly (N, N-diethyl-2-aminoethyl methacrylate) as a dye enhancer as an additive relative to the solid content of the polymer, 0.1% titanium dioxide as a light-resistant agent, 0.26% by weight magnesium stearate as a disintegration enhancer, and 2% by weight of stearic acid and 1% by weight of melamine polyphosphate as a chlorinating agent, and ₄ % by weight of hydrotalcite Mg ₄ Al ₂ (OH) ₁₂ CO ₃ · H ₂ O coated with 1% by weight. Additionally 0.8% by weight of symmetric di hindered hydroxy phenyl-based compound tetrakis [methylene-2- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] methane, asymmetric dihindered Hydroxy phenyl compound triethylene glycol-bis-3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionate 0.8% by weight and semidicarbazide compound 1,1,1 ', 1.5 wt% of 1'-tetramethyl-4,4 '(methylene-di-p-phenylene) difemicarbazide was added and mixed to obtain a spinning solution.

After degassing the spinning stock solution, the spinning temperature was 260 ° C. in the dry spinning process, and the winding speed was wound at 900 m / min to prepare 3 filament 40 denier spandex yarn, and its chlorine resistance was evaluated and shown in Table 1 below.

       In order to evaluate the chlorine resistance of the obtained spandex yarn, strong retention in chlorine water was evaluated by the following method.

The spandex yarn was treated for 1 hour in water at 99-100 ° C. under 50% elongation, dried and cooled at room temperature, and then immersed in 45 L chlorine water at 3.5 ppm of active chlorine and pH 7.0-7.5 for 180 hours at room temperature. The strong retention was calculated by. MEL was used for the strength evaluation, and the sample length was 20 cm and measured at a cross head speed of 1000 mm / min using a cell of 32 kgf.

Strong retention (%) = S / So × 100

(So: strong before processing, S: strong after processing)

   In addition, in order to evaluate the discoloration resistance of the spandex yarn, the difference in discoloration (measurement of color difference) due to three discoloration factors was measured by the following method.

 After weaving the spandex yarn of each experimental example in the form of a fabric, samples were prepared with a width of 5cm and a length of 5cm.

   (1) Heat treatment condition: The heat treatment was performed for 10 minutes in a 200 ℃ oven.

   (2) UV Lamp treatment conditions: left for 24 hours in the UV-B Lamp.

   (3) NOX GAS treatment condition: NOX GAS was generated using Sodium Nitrate and Phosphoric acid and left for 24 hours under the same conditions.

 The discoloration degree showed the discoloration difference (color difference) after calculating to Δb = b2-b1 using b1 as an untreated value and b2 as a treated value.

  Lower value of Δb means that discoloration is improved.

Tris (3,5-di-ter) instead of tetrakis [methylene-2- (3,5-di-tertiary-butyl-4-hydroxyphenyl) propionate] methane, a symmetric dihindered hydroxy phenyl-based compound Spandex was prepared using the same polymer as that of Example 1 in the composition to which sherry-butyl-4-hydroxy-5-methylphenyl) propionate was applied, and the chlorine resistance was evaluated. The results are shown in Table 1 together. .

Semicarbazide-based compound 1,1,1 ', 1'-tetramethyl-4,4' (methylene-di-p-phenylene) difemicarbazide instead of 1,6-hexamethylene bis (N'N-dimethyl Spandex yarn was prepared using the same polymer as that of Example 1 in a composition to which semicarbazide was applied, and chlorine resistance was evaluated. The results are shown in Table 1 together.

Except for the inorganic chlorine agent using a mixed mineral of huntite and hydromagnesite was prepared spandex yarn using the same polymer as in Example 1, and evaluated the chlorine resistance and the results are shown in Table 1 together.

< Comparative example  1>

A spandex yarn was prepared using the same polymer as in Example 1, except that only the symmetric hindered hydroxy phenyl compound was used without using the asymmetric di hindered hydroxy phenyl compound and the semicarbazide compound. Evaluation of chlorine resistance is shown in Table 1 together with the results.

< Comparative example  2>

Spandex yarn was prepared using the same polymer as in Example 1, except that only the asymmetric dihindered hydroxy compound was used without using the symmetrical dihindered hydroxy phenyl compound and the semicarbazide compound. To evaluate the results are shown in Table 1 together.

< Comparative example  3>

A spandex yarn was prepared using the same polymer as in Example 1, except that a symmetrical dihindered hydroxy phenyl chemical and an asymmetrical dihindered hydroxy phenyl based compound were used without using a semicarbazide compound. Evaluation of chlorine resistance is shown in Table 1 together with the results.

< Comparative example  4>

A spandex yarn was prepared using the same polymer as in Example 1, except that the semicarbazide-based compound was used without using the symmetrical dihindered hydroxyphenyl-based compound and the asymmetrical dihindered hydroxyphenyl-based compound. Evaluation of chlorine resistance is shown in Table 1 together with the results.

< Comparative example  5>

Spandex yarn was prepared using the same polymer as in Example 1, except that only the inorganic chlorine-resistant compound was used without using the symmetrical dihindered hydroxyphenyl-based compound, the asymmetrical dihindered hydroxyphenyl-based compound, and the semicarbazide-based compound. To prepare, and evaluated the chlorine resistance the results are shown in Table 1 together.

division Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Thermal discoloration (? B) 3.8 3.8 4.1 4.2 15.1 16.2 17.2 10.4 20.1 UV discoloration (? B) 16.5 15.9 16.2 16.1 16.5 15.1 15.9 24.6 25.7 NOX GAS
Discoloration (△ b) 15.1 16.2 15.9 17.0 40.1 27.5 45.3 7.6 25.4 Strong retention rate (%) 81.4 79.2 80.4 82.3 75.6 73.2 82.1 67.1 64.5

(The smaller * Δb value, the better)

As confirmed through the results of Table 1, the spandex of the present invention comprising a symmetrical dihindered hydroxyphenolic compound, an asymmetrical dihindered hydroxyphenolic compound, a semicarbazide-based compound, and an inorganic chlorine-resistant agent Strong retention in chlorine water was improved and discoloration resistance was improved.

Although the embodiments of the present invention have been described in detail above, these are merely for illustrative purposes and should not be construed as limiting the present invention. It will be apparent to those skilled in the art that many variations and modifications of the above embodiments are possible without departing from the spirit and scope of the invention. The protection scope of the invention should be defined by the appended claims and their equivalents.

Claims (8)

0.1 to 10% by weight of inorganic chlorinating agent, 0.1 to 5% by weight of symmetrical dihindered hydroxyphenyl-based compound, 0.1 to 5% by weight of asymmetrical dihindered hydroxyphenyl-based compound and semicarbazide-based compound on the basis of polyurethane polymer Spandex fiber with improved chlorine resistance and discoloration resistance, characterized in that it comprises 0.1 to 5% by weight.
The method of claim 1, wherein the symmetric di hindered hydroxyphenyl compound is tetrakis [methylene-2- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] methane or tris ( 3,5-di-tert-butyl-4-hydroxy-5-methylphenyl) propionate, 3,3 ', 3 ", 5,5', 5" -hexa-tetra-butyl-a, a ' , a ”-(mesitylene-2,4,6-tril) tri-p-cresol, hexamethylene bis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, 1,2-bis (3,5-di-tert-butyl-4-hydroxyhydroxyanoyl) hydrazine, N, N'-hexamethylenebis (3,5-di-tert-butyl-4- Hydroxyhydrocinamide), 2,4-di-tert-butylphenyl-4'-hydroxy-3 ', 5'-di-tert-butyl benzoate, and at least one member selected from the group consisting of Spandex fiber with improved chlorine resistance and discoloration resistance. The method of claim 1, wherein the asymmetric dihindered hydroxyphenyl compound is triethylene glycol-bis-3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionate, 1,3, 5-tris (2,6-dimethyl-3-hydroxy-4-tert-butylbenzyl) isocyanurate is one or more selected from the group consisting of spandex fiber characterized by improved chlorine resistance and discoloration resistance . The semicarbazide compound according to claim 1, wherein the semicarbazide compound is 1,1,1 ', 1'-tetramethyl-4,4' (methylene-di-p-phenylene) diisemicarbazide, 1,6-hexamethylene Bis (N, N-dimethylsemicarbazide), or biurettri-tri (hexamethylene-N, N-dimethylsemicarbazide) Spandex fiber with improved chlorine resistance and discoloration resistance. The chlorine resistance and discoloration according to claim 1, wherein the inorganic chlorine agent is at least one selected from the group consisting of hydrotalcite compounds, huntite and hydromagnesite mixed minerals, hydromagnesite, zinc oxide, and magnesium oxide. Improved spandex fiber. The method of claim 5, wherein the hydrotalcite compound is Mg _4.5 Al ₂ (OH) ₁₃ CO ₃ · 3.5H ₂ O, Mg ₆ Al ₂ (OH) ₁₆ CO ₃ · 5H ₂ O, Mg ₈ Al ₂ (OH) ₂₀ CO ₃ · 6H ₂ O, Mg ₄ Al ₂ (OH) ₁₂ CO ₃ · 3H ₂ O, Mg _4.5 Al ₂ (OH) ₁₃ CO ₃ , Mg ₆ Al ₂ (OH) ₁₆ CO ₃ , Mg ₈ Al ₂ ( OH) ₂₀ CO ₃ , Mg ₄ Al ₂ (OH) ₂₀ CO ₃ , Mg _4.5 Al ₂ (OH) ₁₃ (CO ₃ ) _0.6 O _0.4 , Mg ₆ Al ₂ (OH) ₁₆ (CO ₃ ) _0.7 O _0.3 , Mg _4.5 Chlorine and discoloration resistance, characterized in that at least one member selected from the group consisting of Al ₂ (OH) _12.2 (CO ₃ ) _0.8 O _0.6 , and Mg ₄ Al ₂ (OH) ₁₂ (CO ₃ ) _0.6 O _0.4 . Improved spandex fiber. The method of claim 5, wherein the hydromagnesite is Mg ₄ (CO ₃ ) ₄ · Mg (OH) ₂ · 4H ₂ O, Mg ₃ (CO ₃ ) ₃ · Mg (OH) ₂ 3H ₂ O, Mg ₄ (CO _{3 4} ) Mg (OH) ₂ , Mg ₃ (CO ₃ ) ₃ , Mg (OH) ₂ , MgCO ₃ Spandex fiber with improved chlorine resistance and discoloration resistance, characterized in that at least one selected from the group consisting of. The method of claim 1, wherein the inorganic chlorinating agent is aliphatic alcohol, fatty acid, fatty acid salt, aliphatic ester, phosphate ester, styrene / maleic anhydride copolymer and derivatives thereof, silane coupling agent, titanate coupling agent, polyorganosiloxane Spandex fiber, characterized in that the coating by at least one coating agent selected from the group consisting of polyorganohydrogensiloxane and melamine-based compounds.