A kind of high-draft spandex fiber and preparation method thereof

Abstract

The invention discloses a high-draw spandex fiber and a preparation method thereof, and belongs to the field of polymer composite materials. The specific preparation method comprises: mixing polytetrahydrofuran ether diol and diphenylmethane-4,4'-diisocyanate to obtain a prepolymer. Then, dimethylacetamide non-protonic polar solvent is added to the prepolymer to obtain a prepolymer solution. Then, ethylenediamine, 1,2-propylenediamine, sodium N-(2-aminoethyl)-2-aminoethanesulfonate, 1,2-cyclohexanediamine and diethylamine are added to carry out chain extension reaction and chain termination reaction to obtain a polyurethaneurea solution. Additives are added to the polyurethaneurea solution to obtain a spandex spinning solution, and then the spandex spinning solution is matured and then the spandex fiber is prepared by dry spinning technology. The spandex fiber obtained by this preparation method has good fracture performance and resilience performance.

Description

Technical Field

[0001] The invention belongs to the field of polymer composite materials, and particularly relates to a high-draft spandex fiber and a preparation method thereof. Background Art

[0002] Spandex fiber is highly elastic, and its soft segment is connected with the hard segment to enhance its properties. It is mainly used in underwear, sportswear and other fabrics. Due to the increasing market demand for spandex fiber and people's high requirements for comfort, some manufacturers reduce production costs by increasing the spinning speed, but this will reduce the performance of spandex. Some manufacturers increase the yarn feeding amount of spandex in the next weaving process and reduce the drafting of spandex to improve the softness of the fabric, but this will lead to an increase in the cost of use.

[0003] In view of the above problems, for example, Chinese patent CN101736435A discloses a method for producing soft spandex, which uses a polymerized polyol with a molecular weight greater than 3000 and a side group to prepare spandex fibers with higher elongation and lower stress, but its breaking strength is significantly reduced, which will cause the spandex fibers to break in subsequent applications. This study involves a method for preparing high-draft spandex, but there are still certain shortcomings.

[0004] Therefore, the prior art urgently needs a technology that can produce high-draft spandex fibers for better industrial production. Summary of the invention

[0005] The object of the present invention is to provide a high-draft spandex fiber and a preparation method thereof, so as to solve the existing problems and meet both the use cost of the spandex fiber and the high-draft requirement thereof.

[0006] In order to solve the above technical problems, the present invention specifically provides the following technical solutions:

[0007] A method for preparing high-draft spandex fiber, comprising:

[0008] A prepolymer is prepared by reacting polytetramethylene glycol and diphenylmethane-4,4' diisocyanate, and then mixed with a non-protonic polar solvent to form a prepolymer solution;

[0009] Then, a chain extender and a chain terminator are added to the prepolymer solution to react to obtain a polyurethane urea solution, and then an additive is added for aging, and spandex fiber is obtained by dry spinning. The chain extender is ethylenediamine, 1,2-propylenediamine, sodium N-(2-aminoethyl)-2-aminoethanesulfonate and 1,2-cyclohexanediamine, and the chain terminator is diethylamine. The sodium N-(2-aminoethyl)-2-aminoethanesulfonate molecule contains not only primary and secondary amino groups that can react with isocyanate groups, and the amino groups react with isocyanate groups to generate urea, but also sulfonate groups that are strong hydrophilic groups. 1,2-cyclohexanediamine can also react with polymers to adjust the molecular weight of the polymers. At the same time, the polyurethane urea solution has low viscosity, can improve the fluidity of the spinning solution, improve the viscosity during the spinning process, and make the polyurethane urea solution more uniform and stable, thereby improving the spinning effect and the performance of the spandex fiber.

[0010] Preferably, polytetramethylene glycol and diphenylmethane-4,4'-diisocyanate are mixed in a mass ratio of 1:0.2-0.3.

[0011] Preferably, the aprotic polar solvent is dimethylacetamide, the mass ratio of the amount of polytetramethylene glycol to the amount of dimethylacetamide added to the prepolymer is 1:1.5-1.8; the additives include anti-yellowing agents and antioxidants, and the mass ratio of the polyurethane urea solution to the additives is 1:0.005-0.03;.

[0012] Preferably, the mass ratio of the amount of polytetramethylene glycol to the amount of ethylenediamine added to the prepolymer solution is 1:0.01-0.03, and the mass ratio of the amount of polytetramethylene glycol to the amount of 1,2-propylenediamine added to the prepolymer solution is 1:0.0002-0.001.

[0013] Preferably, the mass ratio of the amount of polytetrahydrofuran ether diol to the amount of sodium N-(2-aminoethyl)-2-aminoethanesulfonate added to the prepolymer is 1:0.01-0.02, and the mass ratio of the amount of polytetrahydrofuran ether diol to the amount of 1,2-cyclohexanediamine added to the prepolymer is 1:0.0005-0.002.

[0014] Preferably, the mass ratio of the amount of polytetramethylene glycol to the amount of diethylamine added to the prepolymer solution is 1:0.003-0.006.

[0015] Preferably, the reaction temperature in the prepolymer reaction is 60-90°C, the reaction time is 1-2.5 h, the prepolymer cooling temperature before the chain extension reaction is 5-25°C, the spandex spinning solution aging temperature is 55-85°C, and the aging time is 15-30 h.

[0016] Preferably, the present invention discloses a high-draft spandex fiber, including the high-draft spandex fiber prepared by the above method.

[0017] Preferably, the present invention discloses a garment comprising the above-mentioned high-stretch spandex fiber.

[0018] A method for preparing high-draft spandex fiber comprises the following steps:

[0019] S1: polytetrahydrofuran ether diol and diphenylmethane-4,4' diisocyanate are mixed and reacted at 60-90°C for 1-2.5 hours to obtain a prepolymer. Then, dimethylacetamide non-protonic polar solvent is added to the prepolymer to completely dissolve the prepolymer to obtain a prepolymer solution.

[0020] S2: After the prepolymer solution obtained in S1 is cooled to 5-25°C, ethylenediamine, 1,2-propylenediamine, sodium N-(2-aminoethyl)-2-aminoethanesulfonate, 1,2-cyclohexanediamine and diethylamine are added to carry out chain extension reaction and chain termination reaction to obtain a polyurethaneurea solution. Then, the additive is added to the obtained polyurethaneurea solution, and the mixture is mixed to obtain a spandex spinning solution. The spandex spinning solution is then aged at 55-85°C for 15-30 hours.

[0021] S3: The spandex spinning stock solution obtained in S2 is used to prepare spandex fibers using dry spinning technology.

[0022] Preferably, in the above technical solution, polytetramethylene glycol and diphenylmethane-4,4'-diisocyanate in S1 are mixed in a mass ratio of 1:0.2-0.3, and the mass ratio of polytetramethylene glycol to dimethylacetamide added to the prepolymer is 1:1.5-1.8.

[0023] Preferably, in the above technical solution, the mass ratio of the amount of polytetramethylene glycol in S1 to the amount of ethylenediamine added to the prepolymer solution is 1:0.01-0.03, and the mass ratio of the amount of polytetramethylene glycol to the amount of 1,2-propylenediamine added to the prepolymer solution is 1:0.0002-0.001.

[0024] Preferably, in the above technical scheme, the mass ratio of the amount of polytetrahydrofuran ether diol to the amount of sodium N-(2-aminoethyl)-2-aminoethanesulfonate added to the prepolymer is 1:0.01-0.02, the mass ratio of the amount of polytetrahydrofuran ether diol to the amount of 1,2-cyclohexanediamine added to the prepolymer is 1:0.0005-0.002, and the mass ratio of the amount of polytetrahydrofuran ether diol to the amount of diethylamine added to the prepolymer solution is 1:0.003-0.006.

[0025] Preferably, in the above technical solution, the additives in S2 include an anti-yellowing agent and an antioxidant, and the mass ratio of the polyurethane urea solution to the additives is 1:0.005-0.03.

[0026] Preferably, in a preferred embodiment of the present invention, the preparation of high-draw spandex fiber is as follows: first, polytetrahydrofuran ether diol and diphenylmethane-4,4' diisocyanate are mixed and reacted at 60-90 ° C for 1-2.5 h to obtain a prepolymer. Then, dimethylacetamide non-protonic polar solvent is added to the prepolymer to completely dissolve the prepolymer to obtain a prepolymer solution. After the prepolymer solution is cooled to 5-25 ° C, ethylenediamine, 1,2-propylenediamine, sodium N-(2-aminoethyl)-2-aminoethanesulfonate, 1,2-cyclohexanediamine and diethylamine are added to carry out chain extension reaction and chain termination reaction to obtain a polyurethane urea solution. Then, the additive is added to the obtained polyurethane urea solution, and the mixture is mixed to obtain a spandex spinning solution. Then, the spandex spinning solution is aged at 55-85 ° C for 15-30 h. The spandex spinning solution is prepared by dry spinning technology to obtain spandex fiber.

[0027] Preferably, polytetramethylene glycol and diphenylmethane-4,4'-diisocyanate are mixed in a mass ratio of 1:0.2-0.3, and the mass ratio of polytetramethylene glycol to dimethylacetamide added to the prepolymer is 1:1.5-1.8. The mass ratio of the amount of polytetrahydrofuran ether diol to the amount of ethylenediamine added to the prepolymer solution is 1:0.01-0.03, the mass ratio of the amount of polytetrahydrofuran ether diol to the amount of 1,2-propylenediamine added to the prepolymer solution is 1:0.0002-0.001, the mass ratio of the amount of polytetrahydrofuran ether diol to the amount of sodium N-(2-aminoethyl)-2-aminoethanesulfonate added to the prepolymer is 1:0.01-0.02, the mass ratio of the amount of polytetrahydrofuran ether diol to the amount of 1,2-cyclohexanediamine added to the prepolymer is 1:0.0005-0.002, and the mass ratio of the amount of polytetrahydrofuran ether diol to the amount of diethylamine added to the prepolymer solution is 1:0.003-0.006. The additives include anti-yellowing agent HN-150 and antioxidant AO-80, the mass ratio of the polyurethane urea solution to the additives is 1:0.005-0.03, and the mass ratio of the anti-yellowing agent HN-150 added to the polyurethane urea solution to the antioxidant AO-80 added to the polyurethane urea solution is 1:0.5-2.

[0028] More preferably, in the preparation of high-draw spandex fiber, 3-ethoxy-1,2-propylene glycol can be added on the basis of ethylenediamine, 1,2-propylenediamine, diethylamine, sodium N-(2-aminoethyl)-2-aminoethanesulfonate and 1,2-cyclohexanediamine. 3-ethoxy-1,2-propylene glycol can react with isocyanate groups to enhance the cross-linking structure. At the same time, 3-ethoxy-1,2-propylene glycol may affect the molecular chain, thereby improving the spinnability of the spinning solution, and the performance of the spandex fiber is further improved.

[0029] Preferably, the mass ratio of the amount of polytetramethylene glycol to the amount of 3-ethoxy-1,2-propylene glycol is 1:0.1-0.6.

[0030] Preferably, in a preferred embodiment of the present invention, the preparation of high-draw spandex fiber is as follows: first, polytetrahydrofuran ether diol, diphenylmethane-4,4' diisocyanate and 3-ethoxy-1,2-propylene glycol are mixed and reacted at 60-90 ° C for 1-2.5 hours to obtain a prepolymer. Then, dimethylacetamide non-protonic polar solvent is added to the prepolymer to completely dissolve the prepolymer to obtain a prepolymer solution. After the prepolymer solution is cooled to 5-25 ° C, ethylenediamine, 1,2-propylenediamine, sodium N-(2-aminoethyl)-2-aminoethanesulfonate, 1,2-cyclohexanediamine and diethylamine are added to carry out chain extension reaction and chain termination reaction to obtain a polyurethane urea solution. Then, the additive is added to the obtained polyurethane urea solution, and the mixture is mixed to obtain a spandex spinning solution. Then, the spandex spinning solution is aged at 55-85 ° C for 15-30 hours. The spandex spinning solution is prepared by dry spinning technology to obtain spandex fiber.

[0031] Preferably, polytetrahydrofuran ether diol and diphenylmethane-4,4'-diisocyanate are mixed in a mass ratio of 1:0.2-0.3, and the mass ratio of the amount of polytetrahydrofuran ether diol to the amount of 3-ethoxy-1,2-propylene glycol is 1:0.1-0.6. The mass ratio of the amount of polytetrahydrofuran ether diol to the amount of dimethylacetamide added to the prepolymer is 1:1.5-1.8. The mass ratio of the amount of polytetrahydrofuran ether diol to the amount of ethylenediamine added to the prepolymer solution is 1:0.01-0.03, the mass ratio of the amount of polytetrahydrofuran ether diol to the amount of 1,2-propylenediamine added to the prepolymer solution is 1:0.0002-0.001, the mass ratio of the amount of polytetrahydrofuran ether diol to the amount of sodium N-(2-aminoethyl)-2-aminoethanesulfonate added to the prepolymer is 1:0.01-0.02, the mass ratio of the amount of polytetrahydrofuran ether diol to the amount of 1,2-cyclohexanediamine added to the prepolymer is 1:0.0005-0.002, and the mass ratio of the amount of polytetrahydrofuran ether diol to the amount of diethylamine added to the prepolymer solution is 1:0.003-0.006. The additives include anti-yellowing agent HN-150 and antioxidant AO-80, the mass ratio of the polyurethane urea solution to the additives is 1:0.005-0.03, and the mass ratio of the anti-yellowing agent HN-150 added to the polyurethane urea solution to the antioxidant AO-80 added to the polyurethane urea solution is 1:0.5-2.

[0032] Preferably, the present invention also provides a high-draft spandex fiber prepared by the above preparation method.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] The invention obtains a spandex spinning stock solution through prepolymerization, prepolymer dissolution, chain extension reaction and chain termination reaction, and obtains spandex fiber through dry spinning. Ethylenediamine, 1,2-propylenediamine, sodium N-(2-aminoethyl)-2-aminoethanesulfonate, 1,2-cyclohexanediamine and diethylamine are subjected to chain extension reaction and chain termination reaction to improve the performance of the spandex fiber, and on this basis, 3-ethoxy-1,2-propylene glycol is added to participate in the reaction to obtain a spandex fiber with good breaking performance and resilience performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the implementation methods of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the implementation methods or the description of the prior art. Obviously, the drawings in the following description are only exemplary, and for ordinary technicians in this field, other implementation drawings can be derived from the provided drawings without creative work.

[0036] Figure 1 It is the elongation stress retention rate of high-draw spandex fiber. DETAILED DESCRIPTION

[0037] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] The following first describes the concepts involved in the present application in conjunction with the accompanying drawings. It should be noted that the following description of each concept is only to make the content of the present application easier to understand, and does not limit the scope of protection of the present application; at the same time, the embodiments and features in the embodiments of the present application can be combined with each other in the absence of conflict. The present application will be described in detail with reference to the accompanying drawings and in conjunction with the embodiments.

[0039] Embodiment 1:

[0040] Preparation of high-draw spandex fiber: First, polytetrahydrofuran ether diol and diphenylmethane-4,4' diisocyanate were mixed and reacted at 85 °C for 2 h to obtain a prepolymer. Then, dimethylacetamide non-protonic polar solvent was added to the prepolymer to completely dissolve the prepolymer to obtain a prepolymer solution. After the prepolymer solution was cooled to 10 °C, ethylenediamine, 1,2-propylenediamine and diethylamine were added to carry out chain extension reaction and chain termination reaction to obtain a polyurethane urea solution. Then, the additive was added to the obtained polyurethane urea solution and mixed to obtain a spandex spinning solution. Then, the spandex spinning solution was aged at 60 °C for 20 h. The spandex spinning solution was used to prepare spandex fiber by dry spinning technology. Among them, polytetrahydrofuran ether diol and diphenylmethane-4,4'-diisocyanate are mixed in a mass ratio of 1:0.25, and the mass ratio of the amount of polytetrahydrofuran ether diol to the amount of dimethylacetamide added to the prepolymer is 1:1.7. The mass ratio of the amount of polytetrahydrofuran ether diol to the amount of ethylenediamine added to the prepolymer solution is 1:0.02, the mass ratio of the amount of polytetrahydrofuran ether diol to the amount of 1,2-propylenediamine added to the prepolymer solution is 1:0.0004, and the mass ratio of the amount of polytetrahydrofuran ether diol to the amount of diethylamine added to the prepolymer solution is 1:0.005. The additives include anti-yellowing agent HN-150 and antioxidant AO-80, the mass ratio of the mass of the polyurethane urea solution to the additive is 1:0.005, and the mass ratio of the amount of the anti-yellowing agent HN-150 added to the polyurethane urea solution to the amount of the antioxidant AO-80 added to the polyurethane urea solution is 1:1.

[0041] Embodiment 2:

[0042] Preparation of high-draw spandex fiber: First, polytetrahydrofuran ether diol and diphenylmethane-4,4' diisocyanate were mixed and reacted at 85 °C for 2 h to obtain a prepolymer. Then, dimethylacetamide non-protonic polar solvent was added to the prepolymer to completely dissolve the prepolymer to obtain a prepolymer solution. After the prepolymer solution was cooled to 10 °C, ethylenediamine, 1,2-propylenediamine, sodium N-(2-aminoethyl)-2-aminoethanesulfonate, 1,2-cyclohexanediamine and diethylamine were added to carry out chain extension reaction and chain termination reaction to obtain a polyurethane urea solution. Then, the additive was added to the obtained polyurethane urea solution and mixed to obtain a spandex spinning solution. Then, the spandex spinning solution was aged at 60 °C for 20 h. The spandex spinning solution was used to prepare spandex fiber by dry spinning technology. The polytetramethylene glycol and diphenylmethane-4,4'-diisocyanate are mixed in a mass ratio of 1:0.25, and the mass ratio of the polytetramethylene glycol to the dimethylacetamide added to the prepolymer is 1:1.7. The mass ratio of the amount of polytetrahydrofuran ether diol to the amount of ethylenediamine added to the prepolymer solution is 1:0.02, the mass ratio of the amount of polytetrahydrofuran ether diol to the amount of 1,2-propylenediamine added to the prepolymer solution is 1:0.0004, the mass ratio of the amount of polytetrahydrofuran ether diol to the amount of sodium N-(2-aminoethyl)-2-aminoethanesulfonate added to the prepolymer is 1:0.017, the mass ratio of the amount of polytetrahydrofuran ether diol to the amount of 1,2-cyclohexanediamine added to the prepolymer is 1:0.0007, and the mass ratio of the amount of polytetrahydrofuran ether diol to the amount of diethylamine added to the prepolymer solution is 1:0.005. The additives include anti-yellowing agent HN-150 and antioxidant AO-80, the mass ratio of the polyurethane urea solution to the additives is 1:0.005, and the mass ratio of the anti-yellowing agent HN-150 added to the polyurethane urea solution to the antioxidant AO-80 added to the polyurethane urea solution is 1:1.

[0043] Embodiment 3:

[0044] Preparation of high-draw spandex fiber: The preparation of spandex fiber in this embodiment is compared with that in Example 2, except that the mass ratio of the amount of polytetramethylene ether glycol to the amount of sodium N-(2-aminoethyl)-2-aminoethanesulfonate added to the prepolymer is 1:0.02.

[0045] Embodiment 4:

[0046] Preparation of high-draw spandex fiber: The preparation of spandex fiber in this embodiment is different from that in Example 2, except that the mass ratio of the amount of polytetramethylene glycol to the amount of 1,2-cyclohexanediamine added to the prepolymer is 1:0.001.

[0047] Embodiment 5:

[0048] Preparation of high-draw spandex fiber: First, polytetrahydrofuran ether diol, diphenylmethane-4,4' diisocyanate and 3-ethoxy-1,2-propylene glycol were mixed and reacted at 85 °C for 2 h to obtain a prepolymer. Then, dimethylacetamide non-protonic polar solvent was added to the prepolymer to completely dissolve the prepolymer to obtain a prepolymer solution. After the prepolymer solution was cooled to 10 °C, ethylenediamine, 1,2-propylenediamine, sodium N-(2-aminoethyl)-2-aminoethanesulfonate, 1,2-cyclohexanediamine and diethylamine were added to carry out chain extension reaction and chain termination reaction to obtain a polyurethane urea solution. Then, the additive was added to the obtained polyurethane urea solution and mixed to obtain a spandex spinning solution. Then, the spandex spinning solution was aged at 60 °C for 20 h. The spandex spinning solution was used to prepare spandex fiber by dry spinning technology. The polytetramethylene glycol and diphenylmethane-4,4'-diisocyanate are mixed in a mass ratio of 1:0.25, the mass ratio of the polytetramethylene glycol to the 3-ethoxy-1,2-propylene glycol is 1:0.3, and the mass ratio of the polytetramethylene glycol to the dimethylacetamide added to the prepolymer is 1:1.7. The mass ratio of the amount of polytetrahydrofuran ether diol to the amount of ethylenediamine added to the prepolymer solution is 1:0.02, the mass ratio of the amount of polytetrahydrofuran ether diol to the amount of 1,2-propylenediamine added to the prepolymer solution is 1:0.0004, the mass ratio of the amount of polytetrahydrofuran ether diol to the amount of sodium N-(2-aminoethyl)-2-aminoethanesulfonate added to the prepolymer is 1:0.017, the mass ratio of the amount of polytetrahydrofuran ether diol to the amount of 1,2-cyclohexanediamine added to the prepolymer is 1:0.0007, and the mass ratio of the amount of polytetrahydrofuran ether diol to the amount of diethylamine added to the prepolymer solution is 1:0.005. The additives include anti-yellowing agent HN-150 and antioxidant AO-80, the mass ratio of the polyurethane urea solution to the additives is 1:0.005, and the mass ratio of the anti-yellowing agent HN-150 added to the polyurethane urea solution to the antioxidant AO-80 added to the polyurethane urea solution is 1:1.

[0049] Embodiment 6:

[0050] Preparation of high-stretch spandex fiber: The preparation of spandex fiber in this embodiment is different from that in Embodiment 5, except that the mass ratio of the amount of polytetramethylene glycol to the amount of 3-ethoxy-1,2-propylene glycol is 1:0.5.

[0051] Comparative Example 1:

[0052] Preparation of high-stretch spandex fiber: This comparative example is different from Example 2 in that 1,2-cyclohexanediamine is not used, and other conditions and parameters are the same as Example 2.

[0053] Comparative Example 2:

[0054] Preparation of high-stretch spandex fiber: This comparative example is different from Example 2 in that sodium N-(2-aminoethyl)-2-aminoethanesulfonate is not used, and other conditions and parameters are the same as Example 2.

[0055] Experimental Example 1:

[0056] Breaking performance test of high-stretch spandex fiber: The high-stretch spandex fiber prepared in Examples 1-6 and Comparative Examples 1-2 was stretched using a constant-speed moving tensile testing machine, and the maximum load borne by the fiber when it broke was recorded as the breaking strength. The elongation length when the fiber broke was recorded, and its ratio to the length before stretching was calculated as the breaking elongation.

[0057] Table 1 Breaking performance test values ​​of spandex fibers

[0058]

[0059] The results are shown in Table 1. The breaking strength and elongation at break of the spandex fibers prepared in Examples 2, 3, and 4 of the present invention are greater than those in Example 1, indicating that under the structural effect of sodium N-(2-aminoethyl)-2-aminoethanesulfonate and 1,2-cyclohexanediamine, the breaking strength and elongation at break of the spandex fibers can be improved; the breaking strength and elongation at break of the spandex fibers prepared in Examples 5 and 6 of the present invention are greater than those in Example 2, indicating that when sodium N-(2-aminoethyl)-2-aminoethanesulfonate and 1,2-cyclohexanediamine are used to prepare spandex fibers, 3-ethoxy-1,2-propylene glycol can also be used, which can further improve the breaking strength and elongation at break of the spandex fibers. Compared with comparative examples 1 and 2, Example 2 of the present invention shows that the simultaneous use of sodium N-(2-aminoethyl)-2-aminoethanesulfonate and 1,2-cyclohexanediamine has a better effect, and the use of sodium N-(2-aminoethyl)-2-aminoethanesulfonate or 1,2-cyclohexanediamine alone has no obvious effect on improving the breaking strength and elongation at break of spandex fibers.

[0060] Experimental Example 2:

[0061] Rebound performance test of high-stretch spandex fiber: The high-stretch spandex fibers prepared in Examples 1-6 and Comparative Examples 1-2 were stretched using a constant-speed moving tensile testing machine, and the elongation stress when stretched to 300% for the fifth time in the cycle was recorded. The ratio of the elongation stress to the elongation stress when stretched to 300% for the first time was calculated, which is the elongation stress retention rate.

[0062] The results are as follows Figure 1As shown, the elongation stress retention rate of the spandex fiber prepared in Examples 2, 3, and 4 of the present invention is greater than that in Example 1, indicating that under the structural effect of N-(2-aminoethyl)-2-aminoethanesulfonic acid sodium and 1,2-cyclohexanediamine, the resilience of the spandex fiber can be improved; the elongation stress retention rate of the spandex fiber prepared in Examples 5 and 6 of the present invention is greater than that in Example 2, indicating that when using N-(2-aminoethyl)-2-aminoethanesulfonic acid sodium and 1,2-cyclohexanediamine to prepare spandex fiber, 3-ethoxy-1,2-propylene glycol can also be used, which can further improve the elongation stress retention rate of the spandex fiber, that is, improve the resilience. Compared with Comparative Examples 1 and 2, Example 2 of the present invention shows that when N-(2-aminoethyl)-2-aminoethanesulfonic acid sodium and 1,2-cyclohexanediamine are used simultaneously, they have a better effect, and the use of N-(2-aminoethyl)-2-aminoethanesulfonic acid sodium or 1,2-cyclohexanediamine alone has no obvious improvement effect on the resilience of the spandex fiber.

[0063] The embodiments and / or implementation methods described above are only used to illustrate the preferred embodiments and / or implementation methods for realizing the technology of the present invention, and are not intended to limit the implementation methods of the technology of the present invention in any form. Any technical personnel in this field may make slight changes or modifications to other equivalent embodiments without departing from the scope of the technical means disclosed in the content of the present invention, but they should still be regarded as technologies or embodiments that are essentially the same as the present invention.

[0064] This article uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and its core ideas of this application. The above is only the preferred implementation method of this application. It should be pointed out that due to the limitations of textual expression and the objective existence of infinite specific structures, ordinary technicians in this technical field can make several improvements, modifications or changes without departing from the principles of this application, and can also combine the above technical features in an appropriate manner; these improvements, modifications, changes or combinations, or the direct application of the concept and technical solution of the invention to other occasions without improvement, should be regarded as the scope of protection of this application.

Claims

1. A method for preparing a high-draft spandex fiber, comprising: A prepolymer is prepared by reacting polytetramethylene glycol and diphenylmethane-4,4' diisocyanate, and then mixed with a non-protonic polar solvent to form a prepolymer solution; The polytetramethylene glycol and diphenylmethane-4,4'-diisocyanate are mixed in a mass ratio of 1:0.2-0.3; the aprotic polar solvent is dimethylacetamide, and the mass ratio of the amount of polytetramethylene glycol to the amount of dimethylacetamide added to the prepolymer is 1:1.5-1.8; Then, a chain extender and a chain terminator are added to the prepolymer solution to react to obtain a polyurethane urea solution, and then an additive is added for aging, and spandex fibers are obtained by dry spinning; the chain extender includes ethylenediamine, 1,2-propylenediamine, sodium N-(2-aminoethyl)-2-aminoethanesulfonate and 1,2-cyclohexanediamine, and the chain terminator is diethylamine; The mass ratio of the amount of polytetrahydrofuran ether diol to the amount of ethylenediamine added to the prepolymer solution is 1:0.01-0.03, and the mass ratio of the amount of polytetrahydrofuran ether diol to the amount of 1,2-propylenediamine added to the prepolymer solution is 1:0.0002-0.001; the mass ratio of the amount of polytetrahydrofuran ether diol to the amount of sodium N-(2-aminoethyl)-2-aminoethanesulfonate added to the prepolymer is 1:0.01-0.02, and the mass ratio of the amount of polytetrahydrofuran ether diol to the amount of 1,2-cyclohexanediamine added to the prepolymer is 1:0.0005-0.

002.

2. The method for preparing a high-stretch spandex fiber according to claim 1, characterized in that: The additives include anti-yellowing agents and antioxidants, and the mass ratio of the polyurethane urea solution to the additives is 1:0.005-0.

03.

3. The method for preparing a high-stretch spandex fiber according to claim 1, characterized in that: The mass ratio of the amount of the polytetrahydrofuran ether diol to the amount of diethylamine added to the prepolymer solution is 1:0.003-0.

006.

4. The method for preparing a high-stretch spandex fiber according to claim 1, characterized in that: The reaction temperature of the prepolymer reaction is 60-90°C, the reaction time is 1-2.5 h, the cooling temperature of the prepolymer before the chain extension reaction is 5-25°C, the aging temperature of the spandex spinning solution is 55-85°C, and the aging time is 15-30 h.

5. The high-stretch spandex fiber prepared by the method according to any one of claims 1 to 4.

6. A garment comprising the high-stretch spandex fiber according to claim 5.

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