A yellowing-resistant antibacterial conductive elastic spandex and a preparation method thereof

Abstract

The application discloses a novel yellowing-resistant antibacterial conductive elastic spandex and a preparation method thereof. Aliphatic polyols and diisocyanate are used as polyurethane prepolymer raw materials to overcome the yellowing-resistant defect of traditional aromatic spandex. Small-molecule bacteriostatic agents containing tertiary amine groups are introduced through chemical grafting, and natural organic antibacterial agent chitosan is introduced through physical blending, so that the spandex material realizes double antibacterial performance of the inner and outer layers, and the synergy of the two can also improve the conductivity of the spandex, and the elastic spandex with good mechanical properties can be obtained.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of yellowing-resistant antibacterial conductive elastic spandex and its preparation method, belong to spandex field. BACKGROUND

[0002] Spandex, also known as polyurethane elastic fiber, is a chemical synthetic fiber with excellent performance, which has high elongation, good fatigue resistance and good corrosion resistance. Adding a small amount of spandex to fabric can significantly improve fabric performance and increase fabric grade. Therefore, spandex has a wide range of downstream applications, such as spandex widely used in textile and clothing underwear, socks, sportswear, swimwear and other clothing products, providing elasticity and comfort. With the change of consumer concept and the upgrading of consumer demand, the downstream application continues to expand, and the differentiation of spandex function is increasingly required in clothing products, such as better yellowing resistance, antibacterial properties and antistatic properties.

[0003] To solve the above problems, the existing technology has certain related research on the yellowing resistance and antibacterial properties of spandex material. Patent CN101736432A discloses a preparation method of yellowing-resistant spandex elastic fiber. In the reaction process, 0.5-10% IPDI (isophorone diisocyanate) is added, but a small amount of IPDI has limited effect on yellowing resistance improvement, and the yellowing defect has not been effectively solved. Patent CN109295526B discloses a preparation method of antibacterial spandex fiber containing guanidine-based polymer. This technology introduces antibacterial agent guanidine compound into the structure of spandex fiber, but this method has the disadvantage of complex chain extender synthesis. Patent CN115852511A discloses a cool-antistatic spandex and its preparation method, which physically mixes polyurethane prepolymer, silver-coated mica powder, multi-walled carbon nanotubes and auxiliary materials to give spandex conductive properties, but multi-armed carbon nanotubes have high cost and poor dispersion.

[0004] Therefore, it is necessary to develop a simple and practical preparation method of new yellowing-resistant antibacterial conductive elastic spandex to solve the problem of difficult introduction of yellowing resistance, antibacterial properties and conductivity in the existing technology, which is of great significance to meet the differentiated consumer demand of many downstream industries. SUMMARY

[0005] In view of the above problems existing in the prior art, the present application provides a yellowing-resistant antibacterial conductive elastic spandex and its preparation method. The synthesized spandex can achieve good yellowing resistance and antibacterial effect, and can be widely used in the field of underwear, socks, sportswear, swimwear and other clothing products.

[0006] To achieve the above-mentioned purpose, the present application realizes the following technical solutions:

[0007] In a first aspect, the present invention provides a yellowing-resistant, antibacterial, conductive, elastic spandex, the raw materials of which include the following components: aliphatic polyol, diisocyanate, chain extender, terminator, organic small molecule amine antibacterial agent, chitosan antibacterial agent, solvent, and titanium dioxide.

[0008] Preferably, the aliphatic polyol is selected from one or more of polyether polyols, polyester polyols, and small molecule polyols; more preferably, it is an aliphatic diol, such as one or more of polyether diols, polyester diols, and small molecule diols.

[0009] Preferably, the polyether diol includes one or more of polyethylene glycol, polypropylene glycol, and polytetramethylene ether diol, more preferably one or more of polytetramethylene ether diol and polyethylene glycol; the small molecule diol includes one or more of propylene glycol, butanediol, hexanediol, and pentanediol; and the polyester diol includes one or more of polycaprolactone diol and polycarbonate diol.

[0010] Preferably, the diisocyanate includes one or more of isophorone diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, dicyclohexylmethane diisocyanate, and 1,4-cyclohexyl diisocyanate, more preferably one or more of isophorone diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, and dicyclohexylmethane diisocyanate, and more preferably one or more of isophorone diisocyanate, hexamethylene diisocyanate, and dicyclohexylmethane diisocyanate.

[0011] Preferably, the mass ratio of aliphatic polyol to diisocyanate is 10:1 to 4; more preferably 10:2 to 3.

[0012] Preferably, the solvent is one or more of N,N-dimethylacetamide, N,N-dimethylformamide, N-methyl-2-pyrrolidone, dimethylformamide, and dimethyl sulfoxide, and more preferably one or two of N,N-dimethylacetamide and N,N-dimethylformamide.

[0013] Preferably, the amount of solvent used is 1 to 3 times the sum of the mass of the aliphatic polyol and the diisocyanate, more preferably 1 to 1.5 times.

[0014] Preferably, the chain extender is selected from primary amine chain extenders, including one or more of ethylenediamine, propylenediamine, butanediamine, pentanediamine, hexanediamine, 1,4-cyclohexanediamine, isophoronediamine, and 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane, and more preferably one or more of ethylenediamine, propylenediamine, and butanediamine; preferably, the chain extender is 0.5 to 3 wt% of the sum of the mass of the aliphatic polyol and the diisocyanate, and more preferably 1.5 to 2.5 wt%.

[0015] Preferably, the terminator is selected from one or more of diethylamine, dipropylamine, and n-hexylamine, and more preferably from one or more of diethylamine and dipropylamine. Preferably, the terminator is 0.01–1 wt% of the sum of the mass of the aliphatic polyol and the diisocyanate, more preferably 0.05–0.1 wt%.

[0016] Preferably, the organic small molecule amine antibacterial agent is selected from one or more of chlorhexidine acetate, chlorhexidine hydrochloride, N,N-bis(3-aminopropyl)dodecylamine, N,N-bis(3-aminopropyl)methylamine, N,N'-di(2-aminoethyl)-1,3-propanediamine, bis(3-aminopropyl)amine, and N'-[3-(diethylamino)propyl]-N,N-diethylpropane-1,3-diamine, with N,N-bis(3-aminopropyl)dodecylamine, N,N-bis(3-aminopropyl)methylamine, and N,N'-di(2-aminoethyl)-1,3-propanediamine being more preferred. Preferably, the organic small molecule amine antibacterial agent is 0.5–3 wt% of the sum of the mass of the aliphatic polyol and the diisocyanate, more preferably 1–2 wt%.

[0017] Preferably, the chitosan-based antibacterial agent includes one or more of chitosan oligosaccharides, chitosan, carboxymethyl chitosan, chitosan hydrochloride, chitosan quaternary ammonium salt, chitosan sulfate, sulfonated chitosan, and etherified chitosan, with a preference for one or more of chitosan oligosaccharides and chitosan; preferably, low molecular weight chitosan oligosaccharides with a molecular weight of 10 to 2000, and more preferably low molecular weight chitosan oligosaccharides with a molecular weight of 10 to 1000.

[0018] Preferably, the chitosan antibacterial agent is 1 wt% to 3 wt% of the sum of the mass of the aliphatic polyol and the diisocyanate, more preferably 1.5 wt% to 2.5 wt%.

[0019] Preferably, the amount of titanium dioxide added is 1wt% to 1.5wt%, based on the total mass of spandex, wherein the total mass of spandex does not include the mass of solvent, which will be removed during the spinning process.

[0020] Secondly, the present invention provides a method for preparing the above-mentioned yellowing-resistant, antibacterial, conductive, elastic spandex, comprising the following steps:

[0021] 1) Polyurethane prepolymer is obtained by heating and polymerizing aliphatic polyols and diisocyanates;

[0022] 2) Dissolve the prepolymer obtained in step 1) in a solvent, cool it to 0-10℃, add organic small molecule amine antibacterial agent, chain extender and terminator, react fully at 50℃~100℃ for 6h-24h to obtain spinning solution, then add chitosan antibacterial agent and titanium dioxide and mix evenly, vacuum degas, and finally spin to obtain yellowing resistant antibacterial conductive elastic spandex material.

[0023] Preferably, the polymerization reaction temperature in step 1) is 60-120℃, and the reaction time is 60-180 min.

[0024] Preferably, in step 2), the prepolymer obtained in step 1) is dissolved in a solvent, cooled to 0-10°C, and then other raw materials are added.

[0025] The yellowing-resistant and antibacterial elastic spandex prepared by this invention can be widely used in clothing manufacturing and other fields.

[0026] Compared with the prior art, the technical effects achieved by the present invention are as follows:

[0027] (1) According to actual application needs, the present invention can introduce organic small molecule amine antibacterial agents into the molecular structure and physically blend natural chitosan antibacterial agents, which can effectively improve the antibacterial properties of spandex products and achieve dual antibacterial properties of inner and outer layers.

[0028] (2) The spandex synthesized in this invention has excellent elastic recovery rate and elongation at break, which can meet the deformation requirements of different products.

[0029] (3) The spandex prepared by this invention has good resistance to yellowing and can significantly extend the service life of downstream corresponding products;

[0030] (4) The spandex prepared by the present invention has a certain antistatic function, which can reduce the static electricity accumulation of downstream products. Detailed Implementation

[0031] To facilitate understanding of the present invention, the following description, in conjunction with embodiments, will further illustrate the invention. It should be understood that the following embodiments are merely for the purpose of better understanding the invention and do not imply that the invention is limited to these embodiments.

[0032] The main raw materials used in the embodiments and comparative examples of this invention are as follows. Unless otherwise specified, other raw materials and reagents were obtained through commercially available channels:

[0033] Polytetramethylene ether glycol, BASF;

[0034] Diethylamine: BASF;

[0035] Ethylenediamine: BASF;

[0036] N,N-bis(3-aminopropyl)dodecylamine, N,N-bis(3-aminopropyl)methylamine: Suzhou Weidu Chemical Co., Ltd.;

[0037] N,N-Dimethylformamide: Maclean's reagent;

[0038] 4,4-Diphenylmethane diisocyanate: Wanhua Chemical;

[0039] 4,4-Dicyclohexylmethane diisocyanate: Wanhua Chemical;

[0040] Isoflurone diisocyanate; Wanhua Chemical;

[0041] Hexamethylene diisocyanate; Wanhua Chemical;

[0042] Propylenediamine: Damin Chemical;

[0043] Chitosan oligosaccharide: Jinan Haidebei Marine Biological Co., Ltd.;

[0044] Titanium dioxide: Longbai Group.

[0045] Example 1

[0046] First, polytetramethylene ether glycol was pretreated to a liquid state at 70°C and stored. Then, under nitrogen protection, 200g of polytetramethylene ether glycol and 53.91g of dicyclohexylmethane diisocyanate were added to a three-necked flask, stirred at 1000 rpm, and reacted at 80°C for 90 minutes to obtain a prepolymer. The reacted polyurethane prepolymer was uniformly dissolved in 200ml of N,N-dimethylformamide. The system was then cooled to about 10°C, and 100ml of a mixed amine consisting of 5.3g of ethylenediamine, 2.98g of N,N-bis(3-aminopropyl)dodecylamine, and 0.2g of diethylamine was slowly added. The N,N-dimethylformamide solution was mixed evenly and then aged at 50°C for 24 hours to obtain the spandex spinning solution. Then, 5g of chitosan oligosaccharide (molecular weight ≤2000) and 3g of titanium dioxide were added to the spinning solution and mixed evenly. The spinning solution was then subjected to vacuum degassing treatment for 12 hours to ensure that no air bubbles were present in the solution. Finally, the spandex finished product was obtained by spinning and winding using a dry spandex spinning equipment.

[0047] Example 2

[0048] First, polypropylene glycol was pretreated to a liquid state at 70°C and stored. Then, under nitrogen protection, 200g of polypropylene glycol and 53.91g of dicyclohexylmethane diisocyanate were added to a three-necked flask, stirred at 1000 rpm, and reacted at 80°C for 90 minutes to obtain a prepolymer. The reacted polyurethane prepolymer was uniformly dissolved in 200ml of N,N-dimethylformamide. The system was then cooled to about 10°C, and 100ml of a mixed amine consisting of 5.3g of ethylenediamine, 1.45g of N,N-bis(3-aminopropyl)methylamine, and 0.2g of diethylamine was slowly added. The N,N-dimethylformamide solution was mixed evenly and then aged at 50°C for 24 hours to obtain the spandex spinning solution. Then, 5g of chitosan oligosaccharide (molecular weight 2000-3000) and 3g of titanium dioxide were added to the spinning solution and mixed evenly. The spinning solution was then subjected to vacuum degassing treatment for 10 hours to ensure that no air bubbles were present in the solution. Finally, the spandex finished product was obtained by spinning and winding using a dry spandex spinning equipment.

[0049] Example 3

[0050] First, polytetramethylene ether glycol was pretreated to a liquid state at 70°C and stored. Then, under nitrogen protection, 300g of polytetramethylene ether glycol and 68.43g of isophorone diisocyanate were added to a three-necked flask, stirred at 1000 rpm, and reacted at 80°C for 120 min to obtain a prepolymer. The reacted polyurethane prepolymer was uniformly dissolved in 300ml of N,N-dimethylformamide. The system was then cooled to about 10°C, and 150ml of a mixed amine consisting of 8.06g of ethylenediamine, 4.47g of N,N-bis(3-aminopropyl)dodecylamine, and 0.3g of diethylamine was slowly added. The N,N-dimethylformamide solution was mixed evenly and then aged at 50°C for 24 hours to obtain the spandex spinning solution. Then, 7.5g of chitosan oligosaccharide (molecular weight ≤2000) and 4.5g of titanium dioxide were added to the spinning solution and mixed evenly. The spinning solution was then subjected to vacuum degassing treatment for 12 hours to ensure that no air bubbles were present in the solution. Finally, the spandex finished product was obtained by spinning and winding using a dry spandex spinning equipment.

[0051] Example 4

[0052] First, polytetramethylene ether glycol was pretreated to a liquid state at 70°C and stored. Then, under nitrogen protection, 400g of polytetramethylene ether glycol and 51.84g of hexamethylene diisocyanate were added to a three-necked flask, stirred at 1000 rpm, and reacted at 80°C for 150 min to obtain a prepolymer. The reacted polyurethane prepolymer was uniformly dissolved in 400ml of N,N-dimethylformamide. The system was then cooled to about 10°C, and 200ml of a mixed amine consisting of 10.6g of ethylenediamine, 5.96g of N,N-bis(3-aminopropyl)dodecylamine, and 0.4g of diethylamine was slowly added. The N,N-dimethylformamide solution was mixed evenly and then aged at 50°C for 24 hours to obtain the spandex spinning solution. Then, 10g of chitosan oligosaccharide (molecular weight ≤2000) and 5g of titanium dioxide were added to the spinning solution and mixed evenly. The spinning solution was then subjected to vacuum degassing treatment for 12 hours to ensure that no air bubbles were present in the solution. Finally, the spandex finished product was obtained by spinning and winding using a dry spandex spinning equipment.

[0053] Comparative Example 1

[0054] First, polytetramethylene ether glycol was pretreated to a liquid state at 70°C and stored. Then, under nitrogen protection, 200g of polytetramethylene ether glycol and 51.42g of diphenylmethane diisocyanate were added to a three-necked flask, stirred at 1000 rpm, and reacted at 80°C for 90 minutes to obtain a prepolymer. All the reacted polyurethane prepolymer was uniformly dissolved in 200ml of N,N-dimethylformamide. The system was then cooled to approximately 10°C, and 100ml of a mixed amine solution consisting of 5.3g of ethylenediamine, 2.98g of N,N-bis(3-aminopropyl)dodecylamine, and 0.2g of diethylamine was slowly added. The N,N-dimethylformamide solution was mixed evenly and then aged at 50°C for 24 hours to obtain the spandex spinning solution. Then, 5g of chitosan oligosaccharide (molecular weight ≤2000) and 3g of titanium dioxide were added to the spinning solution and mixed evenly. The spinning solution was then subjected to vacuum degassing treatment for 12 hours to ensure that no air bubbles were present in the solution. Finally, the spandex finished product was obtained by spinning and winding using dry spandex spinning equipment.

[0055] Comparative Example 2

[0056] First, polytetramethylene ether glycol was pretreated to a liquid state at 70°C and stored. Then, under nitrogen protection, 200g of polytetramethylene ether glycol and 53.91g of dicyclohexylmethane diisocyanate were added to a three-necked flask, stirred at 1000 rpm, and reacted at 80°C for 90 minutes to obtain a prepolymer. The reacted polyurethane prepolymer was then uniformly dissolved in 200ml of N,N-dimethylformamide. The system was then cooled to approximately 10°C, and 100ml of a mixed amine solution consisting of 5.3g of ethylenediamine, 0.74g of 1,2-propanediamine, and 0.2g of diethylamine was slowly added. The N,N-dimethylformamide solution was mixed evenly and then aged at 50°C for 24 hours to obtain the spandex spinning solution. Then, 5g of chitosan oligosaccharide (molecular weight ≤2000) and 3g of titanium dioxide were added to the spinning solution and mixed evenly. The spinning solution was then subjected to vacuum degassing treatment for 12 hours to ensure that no air bubbles were present in the solution. Finally, the spandex finished product was obtained by spinning and winding using a dry spandex spinning equipment.

[0057] Comparative Example 3

[0058] First, polytetramethylene ether glycol was pretreated to a liquid state at 70°C and stored. Then, under nitrogen protection, 200g of polytetramethylene ether glycol and 53.91g of dicyclohexylmethane diisocyanate were added to a three-necked flask, stirred at 1000 rpm, and reacted at 80°C for 90 minutes to obtain a prepolymer. All the reacted polyurethane prepolymer was uniformly dissolved in 200ml of N,N-dimethylformamide. The system was then cooled to approximately 10°C, and 100ml of a mixed amine solution consisting of 5.3g of ethylenediamine, 2.98g of N,N-bis(3-aminopropyl)dodecylamine, and 0.2g of diethylamine was slowly added. N,N-dimethylformamide solution was mixed evenly and then aged at 50°C for 24 hours to obtain spandex spinning solution. 3g of titanium dioxide was added and mixed evenly. The spinning solution was subjected to vacuum degassing treatment for 12 hours to ensure that no air bubbles were present in the solution. Finally, the spandex finished product was obtained by spinning and winding using dry spandex spinning equipment.

[0059] Comparative Example 4

[0060] First, polytetramethylene ether glycol was pretreated to a liquid state at 70°C and stored. Then, under nitrogen protection, 200g of polytetramethylene ether glycol and 53.91g of dicyclohexylmethane diisocyanate were added to a three-necked flask. The mixture was stirred at 1000r / min and reacted at 80°C for 90min to obtain a prepolymer. The reacted polyurethane prepolymer was uniformly dissolved in 200ml of N,N-dimethylformamide. The system was then cooled to about 10°C, and 100ml of N,N-dimethylformamide solution consisting of a mixed amine (5.3g ethylenediamine, 0.74g 1,2-propanediamine, and 0.2g diethylamine) was slowly added. After mixing thoroughly, the solution was aged at 50°C for 24h to obtain a spandex spinning solution. 3g of titanium dioxide was added and mixed thoroughly. The spinning solution was then subjected to vacuum degassing treatment for 12 hours to ensure that no bubbles were present. Finally, the solution was spun and wound using a dry spandex spinning machine to obtain the finished spandex product.

[0061] Main testing methods

[0062] The mechanical properties of spandex, such as fineness and breaking strength, of each embodiment and comparative example were tested according to the test standards in FZ / T 54010-2014.

[0063] The antibacterial properties of spandex were tested according to GB / T 20944.3—2008 "Evaluation of antibacterial properties of textiles - Part 3: Vibration method", mainly to detect antibacterial properties against Staphylococcus aureus, Candida albicans and Escherichia coli.

[0064] The yellowing resistance of the test samples in each embodiment and comparative example was tested using a 60°C sun lamp aging test chamber for 200 hours.

[0065] The antistatic properties of the test samples in each embodiment and comparative example were tested using a volume surface resistivity tester.

[0066] The overall performance is shown in Table 1:

[0067] Table 1

[0068]

[0069]

[0070] The test data shows that the antibacterial properties of spandex fibers with added low molecular weight chitosan oligosaccharides and organic small molecule tertiary amines are far superior to those of materials prepared with conventional spandex formulations in the comparative example.

[0071] The test data shows that the spandex prepared using aliphatic isocyanates has a much higher resistance to yellowing than the fiber prepared using the phenyl-containing spandex formulation in Comparative Example 1.

[0072] Test data shows that the resistivity of spandex fibers with added small-molecule organic tertiary amines and low-molecular-weight chitosan oligosaccharides is less than 10 Ω·cm. 7 The resistivity of spandex without the addition of small-molecule tertiary amines and chitosan oligosaccharides is higher than 10 ohms. 7 The ohm indicates that the combination of these two can significantly reduce the resistance of spandex, effectively dissipating static electricity and preventing its accumulation.

[0073] In summary, the mechanical properties of the yellowing-resistant, antibacterial, and conductive elastic fiber of the present invention, such as breaking strength and breaking elongation, are close to those of conventional spandex fiber. At the same time, it can endow spandex fiber with yellowing resistance, antibacterial properties, and conductive properties, and has broad application prospects in high-end clothing products.

[0074] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, combinations, or simplifications made without departing from the spirit and principle of the present invention should be considered equivalent substitutions and are included within the protection scope of the present invention.

Claims

1. A yellowing-resistant, antibacterial, conductive, elastic spandex, characterized in that, The raw material composition includes aliphatic polyols, diisocyanates, chain extenders, terminators, chitosan antibacterial agents, organic small molecule amine antibacterial agents, solvents, and titanium dioxide; The organic small molecule amine antibacterial agent is selected from one or more of N,N-bis(3-aminopropyl)dodecylamine, N,N-bis(3-aminopropyl)methylamine, N,N'-di(2-aminoethyl)-1,3-propanediamine, bis(3-aminopropyl)amine, and N-(3-aminopropyl)-N-[2-(dimethylamino)ethyl]propane-1,3-diamine; the chitosan antibacterial agent is selected from chitosan oligosaccharides with a molecular weight of 10 to 2000; and the diisocyanate is selected from one or more of isophorone diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, dicyclohexylmethane diisocyanate, and 1,4-cyclohexyl diisocyanate. The method for preparing the spandex includes the following steps: Step 1) Aliphatic polyols and diisocyanates undergo a heating polymerization reaction to obtain polyurethane prepolymers; Step 2) Dissolve the prepolymer obtained in Step 1) in a solvent, add organic small molecule amine antibacterial agent, chain extender and terminator, react to obtain spinning solution, then add chitosan antibacterial agent and titanium dioxide and mix evenly, vacuum degas, and finally spin to obtain yellowing resistant antibacterial conductive spandex.

2. The spandex according to claim 1, characterized in that, The aliphatic polyol is one or more of polyether diol, polyester diol, and small molecule diol.

3. The spandex according to claim 2, characterized in that, The aliphatic polyol is one or more of polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, propylene glycol, butanediol, hexanediol, pentanediol, polycaprolactone diol, and polycarbonate diol.

4. The spandex according to claim 1, characterized in that, The mass ratio of aliphatic polyol to diisocyanate is 10:1 to 4.

5. The spandex according to claim 4, characterized in that, The mass ratio of aliphatic polyol to diisocyanate is 10:2 to 3.

6. The spandex according to claim 1, characterized in that, The solvent is one or more of N,N-dimethylacetamide, N-methyl-2-pyrrolidone, dimethylformamide, and dimethyl sulfoxide; And / or: the chain extender is selected from one or more of ethylenediamine, propylenediamine, butanediamine, pentanediamine, hexanediamine, 1,4-cyclohexanediamine, isophoronediamine, and 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane; And / or: The terminating agent is selected from one or more of diethylamine, dipropylamine, and n-hexylamine.

7. The spandex according to claim 1 or 6, characterized in that, The solvent is 1 to 3 times the sum of the mass of the aliphatic polyol and the diisocyanate; And / or: the chain extender is 0.5 to 3 wt% of the sum of the mass of the aliphatic polyol and the diisocyanate; And / or: The terminating agent is 0.01 to 1 wt% of the sum of the mass of the aliphatic polyol and the diisocyanate; And / or: The amount of titanium dioxide added is 1wt% to 1.5wt%, based on the total mass of spandex.

8. The spandex according to claim 7, characterized in that, The solvent is 1 to 1.5 times the sum of the mass of the aliphatic polyol and the diisocyanate; And / or: the chain extender is 1.5 to 2.5 wt% of the sum of the mass of the aliphatic polyol and the diisocyanate; And / or: The terminating agent is 0.05 to 0.1 wt% of the sum of the mass of the aliphatic polyol and the diisocyanate.

9. The spandex according to claim 1, characterized in that, The organic small molecule amine antibacterial agent is 0.5 to 3 wt% of the sum of the mass of aliphatic polyol and diisocyanate.

10. The spandex according to claim 9, characterized in that, The organic small molecule amine antibacterial agent is 1-2 wt% of the sum of the mass of aliphatic polyol and diisocyanate.

11. The spandex according to claim 1, characterized in that, Chitosan-based antibacterial agents consist of 1 wt% to 3 wt% of the sum of the mass of aliphatic polyols and diisocyanates.

12. The spandex according to claim 11, characterized in that, Chitosan-based antibacterial agents are 1.5 wt% to 2.5 wt% of the sum of the mass of aliphatic polyols and diisocyanates.

13. The spandex according to claim 1, characterized in that, In the method for preparing spandex, step 1) the polymerization reaction temperature is 60-120℃ and the reaction time is 60-180min; and / or: step 2) the reaction temperature is 50-100℃ and the reaction time is 6h-24h.

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