Spandex fiber easy to dye as well as preparation method and application thereof

Abstract

The invention provides an easy-to-dye spandex fiber as well as a preparation method and application thereof. The easy-to-dye spandex fiber is prepared from polyurethane-urea and thermoplastic polyurethane, the polyurethane-urea and the thermoplastic polyurethane are matched, so that the spandex fiber obtained by spinning has an excellent dyeing effect on the premise of not adding any dyeing auxiliary agent, and has relatively high dye-uptake and relatively high fixation rate on reactive dyes and acid dyes; meanwhile, it can be guaranteed that the obtained spandex fiber has good spinnability and mechanical property, the comprehensive performance is quite excellent, and the use requirements of most textiles are met.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of spandex, and particularly relates to an easy-to-dye spandex fiber and a preparation method and application thereof. BACKGROUND

[0002] Spandex is a kind of elastic fiber, and has good acid and alkali resistance, sweat resistance, seawater resistance, dry cleaning resistance and wear resistance, and also has excellent stretchability, and has been widely applied to various clothes, especially tight-fitting clothes. However, the structure of spandex lacks active groups that can react with dyes like cellulose or protein, so that it is difficult for dye molecules to enter the inside of the spandex fiber, resulting in that it is very difficult to dye spandex products.

[0003] At present, the methods for improving the dyeing effect of spandex mainly include the following two kinds: (1) adding a dyeing aid, but the dyeing aid generally has poor compatibility with spandex, and subsequent migration problems occur, resulting in low color fastness; in addition, part of the dyeing aid will obviously affect the performance of the spandex fiber, resulting in that the performance of the spandex is accelerated in the subsequent processing and use process; (2) modifying the molecular structure of spandex, mainly introducing easy-to-dye structures on the molecular chain of spandex, but this will destroy the molecular structure of spandex itself, resulting in a serious decline in physical and mechanical properties, spinnability and heat resistance, which cannot meet the requirements of most application fields for spandex fibers, and is difficult to popularize and use.

[0004] Therefore, in view of the above technical problems, it is of great significance to develop an easy-to-dye spandex fiber with good dyeing effect and excellent comprehensive performance. SUMMARY

[0005] In view of the deficiencies of the prior art, the purpose of the present application is to provide an easy-to-dye spandex fiber and a preparation method and application thereof, the easy-to-dye spandex fiber has good dyeing effect without adding any dyeing aid, has high dyeing rate and high fixation rate for reactive dyes and acid dyes, and also has excellent spinnability and excellent comprehensive performance.

[0006] To achieve this purpose, the technical scheme adopted by the present application is as follows:

[0007] In a first aspect, the present application provides an easy-to-dye spandex fiber, and the material of the easy-to-dye spandex fiber comprises polyurethane-urea and thermoplastic polyurethane.

[0008] The material of the dyeable spandex fiber provided by the present application comprises polyurethane-urea and thermoplastic polyurethane, and the use of the polyurethane-urea and thermoplastic polyurethane for blending can not only improve the hydrophilicity of the obtained spandex fiber, but also enable the obtained spandex fiber to have excellent dyeing performance without adding any auxiliary dyeing agent, and the obtained spandex fiber has high dye-uptake and high fixation rate for both acid dyes and reactive dyes, and has excellent spinnability and mechanical properties, and has excellent comprehensive performance.

[0009] Preferably, the mass percentage of the thermoplastic polyurethane in the dyeable spandex fiber is 0.1-25%, for example, 0.1%, 0.5%, 1%, 5%, 10%, 15%, 20%, 22%, 24% or 25%, and further preferably 5-15%.

[0010] As a preferred technical solution of the present application, the mass percentage of the thermoplastic polyurethane in the dyeable spandex fiber is limited to 0.1-20%, and further to 5-15%, so that the obtained spandex fiber can have the most excellent dyeing performance and spinnability; if the mass percentage of the thermoplastic polyurethane is too high, the spinnability of the obtained spandex fiber will be reduced; and if the mass percentage of the thermoplastic polyurethane is too low, the dyeing effect of the obtained spandex fiber will be reduced.

[0011] Preferably, the raw materials for preparing the polyurethane-urea comprise a first polyol, a first isocyanate, a diamine chain extender and an amine chain terminator.

[0012] Preferably, the number average molecular weight of the first polyol is 1000-3000, for example, 1000, 1200, 1400, 1600, 1800, 2000, 2200, 2400, 2600, 2800 or 3000.

[0013] Preferably, the first polyol comprises any one or a combination of at least two of polytetramethylene ether glycol, polyethylene glycol or polypropylene glycol, and further preferably polytetramethylene ether glycol.

[0014] Preferably, the first isocyanate comprises any one or a combination of at least two of diphenylmethane diisocyanate, toluene diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate or dicyclohexylmethane diisocyanate, and further preferably diphenylmethane diisocyanate.

[0015] Preferably, the diamine chain extender comprises a diatomic amine having a carbon number of 2-30 (e.g. 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, or 28, etc.), further preferably any one or a combination of ethylenediamine, propylenediamine, butylenediamine, pentanediamine, methylpentanediamine, methylpropylenediamine, hexanediamine, phenylenediamine, phenylenediamine, diaminocyclohexane, or hexamethylenediamine.

[0016] Preferably, the amine chain terminator comprises a monatomic amine having a carbon number of 2-20 (e.g. 2, 4, 6, 8, 10, 12, 14, 16, 18, or 20, etc.), further preferably any one or a combination of diethylamine, isopropylamine, n-butylamine, t-butylamine, hexylamine diethylamine, dimethylamine, di-n-butylamine, di-t-butylamine, diisobutylamine, diisopropylamine, diethylamine, dipropylamine, cyclohexylamine, or ethanolamine.

[0017] Preferably, the molar ratio of the diamine chain extender and the amine chain terminator is (12-24):1, e.g. 12:1, 14:1, 16:1, 18:1, 20:1, 22:1, or 24:1, etc., further preferably (15-22):1; further limiting the molar ratio of the two within the above range can further improve the dyeing effect and spinnability of the obtained spandex fiber, thereby ensuring that it has a high dyeing rate and fixation rate for both acid dyes and reactive dyes without adding any auxiliary dyeing agent.

[0018] Preferably, the polyurethane-urea is prepared by a method comprising the following steps:

[0019] (A1) reacting a first polyol and a first isocyanate to obtain a polyurethane prepolymer, and dissolving the obtained polyurethane prepolymer in a solvent to obtain a polyurethane prepolymer solution;

[0020] (A2) reacting the polyurethane prepolymer solution obtained in step (A1), a diamine chain extender, and an amine chain terminator to obtain a polyurethane-urea solution.

[0021] Preferably, the temperature of the reaction in step (A1) is 70-95℃, e.g. 70℃, 72℃, 74℃, 76℃, 78℃, 80℃, 82℃, 84℃, 86℃, 88℃, 90℃, 92℃, or 95℃, etc.

[0022] Preferably, the time of the reaction in step (A1) is 0.5-5h, e.g. 0.5h, 1h, 2h, 3h, 4h, or 5h, etc.

[0023] Preferably, the mass percentage content of isocyanate groups in the product of step (A1) is 2-3.5%, such as 2%, 2.2%, 2.4%, 2.6%, 2.8%, 3%, 3.2% or 3.5%, etc.

[0024] Preferably, the solvent of step (A1) comprises N,N-dimethylacetamide.

[0025] Preferably, the molar ratio of amine groups to isocyanate groups in the system after the reaction of step (A2) is (1.01-1.4):1, such as 1.01:1, 1.05:1, 1.1:1, 1.2:1, 1.3:1 or 1.4:1, etc., further preferably (1.04-1.2):1.

[0026] Preferably, the molecular weight of the thermoplastic polyurethane is 50000-100000, such as 50000, 60000, 70000, 80000, 90000 or 100000, etc.

[0027] Preferably, the hardness of the thermoplastic polyurethane is 60-95A, such as 60A, 65A, 70A, 75A, 80A, 85A, 90A or 95A, etc., further preferably 75-85A; if the Shore hardness of the thermoplastic polyurethane is too low, it will result in poor mechanical properties of the obtained spandex fiber and will affect the spinnability; and if the Shore hardness of the thermoplastic polyurethane is too high, it will also affect the spinnability of the spandex fiber.

[0028] In the present application, the Shore hardness of the thermoplastic polyurethane is tested according to the method provided in GB / T 531.1.

[0029] Preferably, the raw materials for preparing the thermoplastic polyurethane comprise a second polyol, a second isocyanate and a diol chain extender.

[0030] Preferably, the number average molecular weight of the second polyol is 1000-3000, such as 1000, 1200, 1400, 1600, 1800, 2000, 2200, 2400, 2600, 2800 or 3000, etc.

[0031] Preferably, the second polyol comprises polyethylene glycol and / or polypropylene glycol, further preferably polyethylene glycol.

[0032] As a preferred technical solution of the present application, further preferably, the polyethylene glycol is selected as the second polyol, which helps to further improve the hydrophilicity of the thermoplastic polyurethane, and in turn helps to further improve the dye uptake and fixation rate of the obtained spandex fiber to acid dyes and reactive dyes.

[0033] Preferably, the second isocyanate comprises any one of or a combination of diphenylmethane diisocyanate, toluene diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate or dicyclohexylmethane diisocyanate, further preferably diphenylmethane diisocyanate.

[0034] Preferably, the diol chain extender is a dihydric alcohol having a carbon number of 2-10 (e.g. 2, 3, 4, 5, 6, 7, 8, 9 or 10, etc.).

[0035] Preferably, the dihydric alcohol having a carbon number of 2-10 comprises any one of or a combination of ethylene glycol, propylene glycol, butylene glycol, pentanediol, methylpentanediol, neopentyl glycol, methylpropylene glycol, hexanediol, heptanediol, octanediol or nonanediol.

[0036] Preferably, the thermoplastic polyurethane is prepared by a method comprising the following steps:

[0037] (B1) reacting a second polyol, a second isocyanate and a diol chain extender to obtain a polymer melt;

[0038] (B2) pelletizing and drying the polymer melt obtained in step (B1), dissolving in a solvent to obtain a thermoplastic polyurethane solution.

[0039] Preferably, the reaction in step (B1) is carried out at a temperature of 140-200°C, e.g. 140°C, 150°C, 160°C, 170°C, 180°C, 190°C or 200°C, etc.

[0040] Preferably, the reaction in step (B1) is carried out for a time of 10-50 min, e.g. 10 min, 15 min, 20 min, 25 min, 30 min, 35 min, 40 min, 45 min or 50 min, etc.

[0041] Preferably, the solvent in step (B2) comprises N,N-dimethylacetamide.

[0042] In the present application, since the preparation of the polyurethane-urea and the thermoplastic polyurethane is carried out in a solvent, and the final product is a polyurethane-urea solution and a thermoplastic polyurethane solution, the mixture of the two can be directly spun without the need for additional solvent in the spinning process.

[0043] In a second aspect, the present application provides a method for preparing the dyeable spandex fiber as described in the first aspect, the method comprising: mixing the polyurethane-urea and the thermoplastic polyurethane, and spinning to obtain the dyeable spandex fiber.

[0044] Preferably, the spinning is dry spinning.

[0045] Preferably, the post-spinning further comprises the steps of spraying, stretching and drying.

[0046] In a third aspect, the present application provides a textile comprising the dyeable spandex fiber according to the first aspect.

[0047] Compared with the prior art, the present application has the following beneficial effects:

[0048] The dyeable spandex fiber provided by the present application comprises polyurethane-urea and thermoplastic polyurethane; by selecting polyurethane-urea and thermoplastic polyurethane for matching, the spandex fiber obtained by spinning has excellent dyeing effect without adding any dyeing auxiliary agent, has high dye-uptake and high fixation rate for both reactive dyes and acid dyes, and can also ensure that the obtained spandex fiber has good spinnability and mechanical properties, and the comprehensive performance is very excellent, meeting the use requirements of most textiles. DETAILED DESCRIPTION

[0049] The technical solutions of the present application will be further described through specific embodiments. Those skilled in the art should understand that the embodiments are only used to help understand the present application, and should not be regarded as specific limitations on the present application.

[0050] Unless otherwise specified, the raw materials and equipment involved in the following examples and comparative examples are all conventional materials and equipment in the art.

[0051] Example 1

[0052] A dyeable spandex fiber, the material of which comprises 90% by mass of polyurethane-urea and 10% by mass of thermoplastic polyurethane;

[0053] The preparation method of the polyurethane-urea comprises the following steps:

[0054] (1) polytetramethylene ether glycol (PTMEG, number average molecular weight 1800) and diphenyl methane diisocyanate (MDI) are reacted at 75℃ for 4.5h to obtain a polyurethane prepolymer with a mass content of -NCO of 2.65%, and then the obtained polyurethane prepolymer is dissolved in N,N-dimethylacetamide to obtain a polyurethane prepolymer solution with a mass content of 35%;

[0055] (2) adding ethylenediamine and diethylamine with a molar ratio of 20:1 to the polyurethane prepolymer solution obtained in step (1) to make the total mass content of ethylenediamine and diethylamine in the solution be 8%, and controlling the molar ratio of amino group to -NCO after the chain extension reaction is finished to be 1.04:1, to obtain a polyurethane-urea solution;

[0056] The thermoplastic polyurethane has a number average molecular weight of 50000 and a hardness of 75A, and the preparation method comprises the following steps:

[0057] (1) polyethylene glycol (PEG, number average molecular weight 2000), ethylene glycol and diphenyl methane diisocyanate (MDI) are mixed and reacted in a mixing system and fed into a twin-screw extruder, wherein the temperature of the screw is 145-180°C;

[0058] (2) the polymer melt obtained in step (1) is cut underwater and dried to obtain thermoplastic polyurethane particles, which are dissolved in N,N-dimethylacetamide to obtain a thermoplastic polyurethane solution with a mass content of 35%;

[0059] The preparation method of the dyeable spandex fiber provided in this embodiment 1 comprises: mixing the obtained polyurethane-urea solution and the obtained thermoplastic polyurethane solution, aging, and then dry spinning through a spinneret assembly at a speed of 900 m / min at 260°C, and then blowing, stretching and drying to form a 40D dyeable spandex fiber.

[0060] Embodiment 2

[0061] A dyeable spandex fiber, the material of which comprises 85% by mass of polyurethane-urea and 15% by mass of thermoplastic polyurethane;

[0062] The preparation method of the polyurethane-urea comprises the following steps:

[0063] (1) polytetramethylene ether glycol (PTMEG, number average molecular weight 2000) and diphenyl methane diisocyanate (MDI) are reacted at 80°C for 4h to obtain a polyurethane prepolymer with a mass content of 2.55% of -NCO, and then the obtained polyurethane prepolymer is dissolved in N,N-dimethylacetamide to obtain a polyurethane prepolymer solution with a mass content of 35%;

[0064] (2) ethylenediamine and diethylamine with a molar ratio of 22:1 are added to the polyurethane prepolymer solution obtained in step (1) to make the total mass content of ethylenediamine and diethylamine in the solution be 8% and control the molar ratio of amino groups to -NCO after the chain extension reaction is completed to be 1.2:1, to obtain a polyurethane-urea solution;

[0065] The thermoplastic polyurethane has a number average molecular weight of 80000 and a hardness of 80A, and the preparation method comprises the following steps:

[0066] (1) adding polyethylene glycol (PEG, number average molecular weight 3000), ethylene glycol and diphenyl methane diisocyanate (MDI) into a twin-screw extruder through a mixing system for mixed reaction to obtain a polymer melt, wherein the temperature of the screw is 145-180℃;

[0067] (2) underwater cutting and drying the polymer melt obtained in step (1) to obtain thermoplastic polyurethane particles, and dissolving the particles in N,N-dimethylacetamide to obtain a thermoplastic polyurethane solution with a mass content of 35%;

[0068] The method for preparing the easy-to-dye spandex fiber provided in this embodiment 2 comprises: mixing the obtained polyurethane-urea solution and the obtained thermoplastic polyurethane solution, aging, and then performing dry spinning at a speed of 900 m / min at 260℃ through a spinneret assembly, and then performing blowing, stretching and drying to form an easy-to-dye spandex fiber with a diameter of 40D.

[0069] Embodiment 3

[0070] An easy-to-dye spandex fiber, the material of which comprises 95% by mass of polyurethane-urea and 5% by mass of thermoplastic polyurethane;

[0071] The method for preparing the polyurethane-urea comprises the following steps:

[0072] (1) reacting polytetramethylene ether glycol (PTMEG, number average molecular weight 1800) and diphenyl methane diisocyanate (MDI) at 80℃ for 4h to obtain a polyurethane prepolymer with a mass content of -NCO of 2.45%, and then dissolving the obtained polyurethane prepolymer in N,N-dimethylacetamide to obtain a polyurethane prepolymer solution with a mass content of 35%;

[0073] (2) adding ethylenediamine and diethylamine with a molar ratio of 15:1 to the polyurethane prepolymer solution obtained in step (1) to make the total mass content of ethylenediamine and diethylamine in the solution be 8%, and controlling the molar ratio of amino group to -NCO after the chain extension reaction is completed to be 1.2:1 to obtain a polyurethane-urea solution;

[0074] The number average molecular weight of the thermoplastic polyurethane is 100000, and the hardness is 85A, and the method for preparing the thermoplastic polyurethane comprises the following steps:

[0075] (1) adding polyethylene glycol (PEG, number average molecular weight 1000), ethylene glycol and diphenyl methane diisocyanate (MDI) into a twin-screw extruder through a mixing system for mixed reaction to obtain a polymer melt, wherein the temperature of the screw is 145-180℃;

[0076] (2) melt the polymer obtained in step (1) to underwater cutting and drying to obtain thermoplastic polyurethane particles, and dissolving in N,N-dimethylacetamide to obtain a thermoplastic polyurethane solution with a mass content of 35%;

[0077] The method for preparing the easy-to-dye spandex fiber provided in this embodiment 3 comprises: mixing the obtained polyurethane-urea solution and the obtained thermoplastic polyurethane solution, aging, and then performing dry spinning through a spinneret assembly at a speed of 900 m / min at 260℃, and then performing blowing, stretching and drying to form a 40D easy-to-dye spandex fiber.

[0078] Embodiment 4

[0079] An easy-to-dye spandex fiber, which is different from that of embodiment 1 in that the mass percentage content of polyurethane-urea in the easy-to-dye spandex fiber is 80%, the mass percentage content of thermoplastic polyurethane is 20%, and other substances, amounts and preparation methods are the same as those of embodiment 1.

[0080] Embodiment 5

[0081] An easy-to-dye spandex fiber, which is different from that of embodiment 1 in that the mass percentage content of polyurethane-urea in the easy-to-dye spandex fiber is 75%, the mass percentage content of thermoplastic polyurethane is 25%, and other substances, amounts and preparation methods are the same as those of embodiment 1.

[0082] Embodiment 6

[0083] An easy-to-dye spandex fiber, which is different from that of embodiment 1 in that the mass percentage content of polyurethane-urea in the easy-to-dye spandex fiber is 99.9%, the mass percentage content of thermoplastic polyurethane is 0.1%, and other substances, amounts and preparation methods are the same as those of embodiment 1.

[0084] Embodiment 7

[0085] An easy-to-dye spandex fiber, which is different from that of embodiment 1 in that the mass percentage content of polyurethane-urea in the easy-to-dye spandex fiber is 99.99%, the mass percentage content of thermoplastic polyurethane is 0.01%, and other substances, amounts and preparation methods are the same as those of embodiment 1.

[0086] Embodiments 8-11

[0087] An easy-to-dye spandex fiber, which is different from that of embodiment 6 in that in step (2) of the preparation method of polyurethane-urea, the molar ratio of ethylenediamine to diethylamine is 12:1 (embodiment 8), 11:1 (embodiment 9), 24:1 (embodiment 10) and 25:1 (embodiment 11), respectively, and other substances, amounts and preparation methods are the same as those of embodiment 6.

[0088] Embodiment 12

[0089] A dyeable spandex fiber, which is different from Example 1 in that polypropylene glycol (number average molecular weight 2000) is used to replace polyethylene glycol, and other substances, amounts and preparation methods are referred to Example 1.

[0090] Example 13

[0091] A dyeable spandex fiber, which is different from Example 1 in that polytetramethylene ether glycol (number average molecular weight 2000) is used to replace polyethylene glycol, and other substances, amounts and preparation methods are referred to Example 1.

[0092] Examples 14-15

[0093] A dyeable spandex fiber, which is different from Example 1 in that the Shore hardness of the thermoplastic polyurethane is 55A (Example 14) and 60D (Example 15), respectively, and other substances, amounts and preparation methods are referred to Example 1.

[0094] Comparative Example 1

[0095] A spandex fiber, which is made of 100% thermoplastic polyurethane-urea.

[0096] The preparation method of the spandex fiber provided by Comparative Example 1 includes the following steps:

[0097] (1) polytetramethylene ether glycol (PTMEG, number average molecular weight 1800) and diphenyl methane diisocyanate (MDI) are reacted at 75°C for 4.5h to obtain a polyurethane prepolymer with a mass content of -NCO of 2.65%, and then the obtained polyurethane prepolymer is dissolved in N,N-dimethylacetamide to obtain a polyurethane prepolymer solution with a mass percentage of 35%;

[0098] (2) ethylenediamine and diethylamine with a molar ratio of 20:1 are added to the polyurethane prepolymer solution obtained in step (1) to make the total mass content of ethylenediamine and diethylamine in the solution 8%, and the molar ratio of amino group to -NCO after the chain extension reaction is controlled to be 1.02:1, to obtain a polyurethane-urea solution;

[0099] (3) the polyurethane-urea solution obtained in step (2) is matured and then spun through a spinneret assembly at 260°C at a speed of 900m / min, and after blowing, stretching and drying, a 40D spandex fiber is obtained.

[0100] Comparative Example 2

[0101] A spandex fiber, which is made of 100% thermoplastic polyurethane;

[0102] The preparation method of spandex fiber provided by Comparative Example 2 includes the following steps:

[0103] (1) polyethylene glycol (PEG, number average molecular weight 2000), ethylene glycol and diphenyl methane diisocyanate (MDI) are mixed and reacted in a twin-screw extruder through a mixing system, to obtain a polymer melt, wherein the temperature of the screw is 145-180℃;

[0104] (2) the polymer melt obtained in step (1) is cut underwater and dried to obtain thermoplastic polyurethane particles, which are dissolved in N,N-dimethylacetamide to obtain a thermoplastic polyurethane solution with a mass content of 35%;

[0105] (3) the thermoplastic polyurethane solution obtained in step (2) is matured and then dry spun through a spinneret assembly at 260℃ at a speed of 900m / min, and the result shows that it is not spinnable.

[0106] Performance test:

[0107] (1) dye uptake and color fastness (fixation rate):

[0108] First, the spandex fiber is dyed, and then the maximum absorbance of the dyeing solution before and after dyeing is measured by a UV-visible spectrophotometer, and then the dye uptake is calculated according to the following formula: dye uptake = (A0-A1) / A0 x 100%, wherein A0 and A1 are the absorbance of the dyeing solution before and after dyeing, respectively;

[0109] The color fastness of the spandex fiber after acid dyeing and reactive dyeing is tested according to the scheme provided in GB / T 3921-2008 "Textile color fastness test soaping fastness", and the standard color transfer sample is used to distinguish the color transfer level into 1, 1-2, 2, 2-3, 3, 3-4, 4, 4-5 and 5, and the closer to 5, the more it indicates that no color transfer occurs;

[0110] ① Acid dyeing method: first, prepare an acid dyeing solution with a dye concentration of 2g / L and a pH value of 4.5, wherein the dye is weak acid red and the bath ratio is 1:40; then immerse the spandex fiber into the dyeing cup containing the acid dyeing solution, and then put the dyeing cup containing the acid dyeing solution and the spandex fiber into the dyeing machine, and raise the temperature from 40℃ to 100℃ at a rate of 1℃ / min, and keep the temperature for 30min, after the dyeing is completed, take out the sample and rinse it in water until the water does not change color, and then dry it at room temperature;

[0111] ② Reactive dyeing method: First, prepare a reactive dye solution with a dye concentration of 10 g / L, add anhydrous sodium sulfate to make the concentration 20 g / L, wherein the dye is reactive red and the liquor ratio is 1:40; then, immerse the spandex fiber in the dyeing cup containing the above reactive dye solution, and then place the dyeing cup containing the reactive dye solution and spandex fiber into the dyeing sample machine, and heat it from room temperature to 85°C at a rate of 1°C / min, and continue to add anhydrous sodium sulfate (compared to the above reactive dye solution concentration of 20 g / L) and anhydrous sodium carbonate to the dyeing vat (compared to the above reactive dye solution concentration of 10 g / L), and keep it at this temperature for 30 min; after dyeing, take out the sample and rinse it in clean water until the water does not change color, and then air dry it at room temperature.

[0112] (2) Spinability: During the spinning process, a full roll rate of ≥97% is excellent, ≥95% and <97% is good, ≥90% and <95% is average, and <90% is poor; Full roll rate (%) = (full roll production / total production) × 100%.

[0113] (3) Strength at 300% elongation (SS300): The test was conducted in accordance with the method provided in industry standard FZ / T 50006-2013 "Test Method for Tensile Properties of Spandex Filament".

[0114] The spandex fibers provided in Examples 1-15 and Comparative Examples 1-2 were tested according to the above test methods, and the test results are shown in Table 1:

[0115] Table 1

[0116]

[0117]

[0118] According to the data in Table 1:

[0119] The composite spandex fiber provided in the examples has high dyeing rate and color fastness (fixation rate) for both acid dyes and reactive dyes, and also has good spinnability; while the spandex fiber provided in Comparative Example 1, because it does not contain thermoplastic polyurethane, although it has excellent spinnability, has low dyeing rate and color fastness for both acid dyes and reactive dyes, and poor dyeing performance; while the case provided in Comparative Example 2 cannot be spun and has no spinnability.

[0120] The applicant declares that this invention illustrates an easily dyeable spandex fiber, its preparation method, and its application through the above embodiments. However, this invention is not limited to the above embodiments, meaning that this invention does not necessarily rely on the above embodiments for implementation. Those skilled in the art should understand that any improvements to this invention, equivalent substitutions of raw materials for the product of this invention, additions of auxiliary components, and selection of specific methods, all fall within the protection and disclosure scope of this invention.

Claims

1. A dyeable spandex fiber, characterized by, The material of the dyeable spandex fiber comprises polyurethane-urea and thermoplastic polyurethane.

2. The dyeable spandex fiber according to claim 1, wherein, The mass percentage of the thermoplastic polyurethane in the dyeable spandex fiber is 0.1-25%, preferably 5-15%.

3. The dyeable spandex fiber according to claim 1 or 2, characterized in that, The raw material of the polyurethane-urea comprises a first polyol, a first isocyanate, a diamine chain extender and an amine chain terminator. Preferably, the number average molecular weight of the first polyol is 1000-3000. Preferably, the first polyol comprises any one or a combination of at least two of polytetramethylene ether glycol, polyethylene glycol or polypropylene glycol, further preferably polytetramethylene ether glycol. Preferably, the first isocyanate comprises any one or a combination of at least two of diphenylmethane diisocyanate, toluene diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate or dicyclohexylmethane diisocyanate, further preferably diphenylmethane diisocyanate. Preferably, the diamine chain extender comprises a binary amine with a carbon atom number of 2-30, further preferably any one or a combination of at least two of ethylenediamine, propylenediamine, butylenediamine, pentanediamine, methylpentanediamine, methylpropylenediamine, hexanediamine, phenylenediamine, benzidine, diaminocyclohexane or hexamethylenediamine. Preferably, the amine chain terminator comprises a monovalent amine with a carbon atom number of 2-20, further preferably any one or a combination of at least two of diethylamine, isopropylamine, n-butylamine, t-butylamine, hexylamine diethylamine, dimethylamine, di-n-butylamine, di-t-butylamine, diisobutylamine, diisopropylamine, diethylamine, dipropylamine, cyclohexylamine or ethanolamine. Preferably, the molar ratio of the diamine chain extender and the amine chain terminator is (12-24):1, further preferably (15-22):

1.

4. The dyeable spandex fiber according to claim 3, wherein, The polyurethane-urea is prepared by a method comprising the following steps: (A1) reacting the first polyol and the first isocyanate to obtain a polyurethane prepolymer, and dissolving the polyurethane prepolymer in a solvent to obtain a polyurethane prepolymer solution; (A2) reacting the polyurethane prepolymer solution obtained in step (A1), the diamine chain extender and the amine chain terminator to obtain a polyurethane-urea solution; Preferably, the reaction in step (A1) is carried out at a temperature of 70-95℃ for 0.5-5h. Preferably, the mass percentage of isocyanate groups in the polyurethane prepolymer in step (A1) is 2-3.5%. Preferably, the molar ratio of amine groups to isocyanate groups in the system after the reaction in step (A2) is (1.01-1.4):1, further preferably (1.04-1.2):

1.

5. The dyeable spandex fiber according to any one of claims 1 to 4, characterized in that, The molecular weight of the thermoplastic polyurethane is 50000-100000. Preferably, the hardness of the thermoplastic polyurethane is 60-95A, further preferably 75-85A. Preferably, the raw material of the thermoplastic polyurethane comprises a second polyol, a second isocyanate and a diol chain extender. Preferably, the number average molecular weight of the second polyol is 1000-3000. Preferably, the second polyol comprises polyethylene glycol and / or polypropylene glycol, further preferably polyethylene glycol; Preferably, the second isocyanate comprises any one or a combination of at least two of diphenylmethane diisocyanate, toluene diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate or dicyclohexylmethane diisocyanate, further preferably diphenylmethane diisocyanate; Preferably, the diol chain extender is a dihydric alcohol having a carbon number of 2-10, further preferably any one or a combination of at least two of ethylene glycol, propylene glycol, butylene glycol, pentylene glycol, methylpentylene glycol, neopentylene glycol, methylpropylene glycol, hexylene glycol, heptylene glycol, octylene glycol or nonylene glycol.

6. The dyeable spandex fiber according to claim 5, wherein, The thermoplastic polyurethane is prepared by a method comprising the following steps: (B1) reacting a second polyol, a second isocyanate and a diol chain extender to obtain a polymer melt; (B2) pelletizing and drying the polymer melt obtained in step (B1) and dissolving in a solvent to obtain a thermoplastic polyurethane solution; Preferably, the reaction in step (B1) is carried out at a temperature of 140-200°C for 10-50 min.

7. A process for the production of dyeable spandex fiber as claimed in any one of claims 1 to 6, characterized in that, The preparation method comprises mixing the polyurethane-urea and the thermoplastic polyurethane and spinning to obtain the easy-to-dye spandex fiber.

8. The preparation method according to claim 7, characterized in that, The spinning is dry spinning.

9. The production method according to claim 7 or 8, characterized by, The spinning further comprises the steps of blowing, drawing and drying.

10. A textile, characterized in that, The textile comprises the easy-to-dye spandex fiber according to any one of claims 1-6.

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