Antistatic dyeable spandex fiber and method of making same

Abstract

This invention provides an antistatic dyeable spandex fiber and its preparation method. During spandex production, N-(2-hydroxyethyl)ethylenediamine is used as a terminating agent for chain extension, combined with the use of the stabilizer TAD, to prepare antistatic dyeable spandex fiber. This improves the dyeing rate and color fastness of spandex fiber to acid dyes and reactive dyes. Furthermore, the heat-resistant dyeable spandex can meet the high-temperature dyeing requirements in the polyester / spandex field. Simultaneously, the improved antistatic properties of the spandex fiber reduce the amount of oiling agents used by spandex manufacturers, thereby lowering production costs. For subsequent processes, it reduces the defect rate in dyeing, finishing, and weaving, saving costs.

Description

Technical Field

[0001] This invention belongs to the field of textiles, specifically relating to an antistatic dyeable spandex fiber and its preparation method. Background Technology

[0002] Spandex is a high-elongation, high-resilience elastic fiber. Adding even a small amount can significantly improve the elasticity of fabrics, earning it the nickname "MSG" of textiles. It is widely used in various textile fabrics. However, spandex also has significant drawbacks. Its dyeing performance is poor, and noticeable color differences appear after blending and dyeing with other fibers. Disperse dyes, acid dyes, and reactive dyes all struggle to stably dye spandex and achieve high colorfastness. Furthermore, extreme dyeing conditions, such as high-temperature dyeing with disperse dyes, are often used to improve the dyeing effect. However, the dyeing and finishing process often causes a decrease in the tensile strength of spandex fibers, or even micro-breakage, thus affecting the elasticity and usability of the fabric.

[0003] To improve the dyeing performance of spandex, technicians mainly use the following methods: 1. Improve the heat resistance of spandex to adapt to the high-temperature and high-pressure dyeing of disperse dyes; 2. Introduce amine dye sites that bind with dyes into the spandex molecular chain to improve the binding ability of spandex with acid dyes, reactive dyes, etc.; 3. Reduce the regularity of the hard segments of spandex molecules, making it easier for dye molecules to penetrate into the interior of spandex fibers; 4. Use dyeable additives to improve the dyeing ability of spandex.

[0004] Patent CN105837780B improves the dyeing ability of acid dyes by introducing amino dye sites into spandex molecules using tetramethylpiperidineamine or tetramethylpiperidine alcohol as co-chain extenders. Patent CN112127006A uses 2,4-diphenylmethane diisocyanate, 4,4-diphenylmethane diisocyanate and polytetramethylene ether glycol to prepare spandex fibers in the hope of improving the dyeing ability of the fibers. Patent CN121183456A prepares acid dye-dyeable spandex by preparing a mixture of hydrophilic polyurethane dosing and normal polyurethane dosing, wherein the hydrophilic polyurethane dosing uses a highly hydrophilic polyether polyol instead of conventional polyether glycol. Patent CN107858766B improves the dyeing performance of fibers by adding N-n-alkyl diethanolamine additives to polyurethane dosing. Patent CN103696038A prepares easily dyeable spandex fibers by adding silica to prepolymer solution and utilizing the strong adsorption properties of silica.

[0005] In existing processes for preparing dyeable spandex, while improving heat resistance can improve dyeing performance to some extent, the colorfastness is very low because no dyeing groups are introduced. Patent CN112127006A, which uses 2,4-diphenylmethane diisocyanate to reduce the molecular regularity of spandex, also fails to effectively improve the dyeing ability and colorfastness of spandex. Patent CN105837780B, while effectively improving the binding ability of spandex fibers to acid dyes by introducing amine dye sites, for hydrophobic spandex fibers, the increased amine content further increases static electricity, greatly affecting warping and weaving processes. Patent CN121183456A also suffers from high static electricity. Furthermore, its method... Using highly hydrophilic polyether polyols significantly alters the main chain molecular structure of spandex, making its physical properties unsuitable for most varieties. Patents CN107858766B and CN103696038A both attempt to improve the dyeing properties of spandex using auxiliaries. The former uses N-alkyldiethanolamine additives at levels far exceeding those of conventional spandex auxiliaries, making it difficult to guarantee uniform dispersion and resulting in poor dyeing uniformity. The latter uses silica, which not only involves a complex preparation process but also suffers from low color fastness. Furthermore, regardless of the type of dyeing auxiliary, none of these auxiliaries chemically bond with the fiber, thus acting as small-molecule plasticizers within the fiber and consequently affecting its strength and elongation properties. Summary of the Invention

[0006] To address the aforementioned problems, this invention primarily improves upon the following: It replaces traditional diethylamine with N-(2-hydroxyethyl)ethylenediamine as a terminator. N-(2-hydroxyethyl)ethylenediamine contains a primary amine group, a hindered secondary amine group, and a hydroxyl group in its molecular structure. When participating in the polymerization reaction simultaneously with diamine chain extenders, the secondary amine group and hydroxyl group in N-(2-hydroxyethyl)ethylenediamine do not react with the NCO group due to the excess of the primary amine group. Therefore, the secondary amine group can act as a dye seat to bind acid dyes, improving the dyeing performance of spandex and nylon blends. Furthermore, compared to diethylamine, the urea bond structure formed by the reaction of the primary amine group and the NCO group in N-(2-hydroxyethyl)ethylenediamine is more stable and will not undergo a desealing reaction to release the NCO group under the high-temperature environment of the spinning tunnel. Therefore, in addition to the amine group at the end of the terminator chain, the amine group at the end of the chain extender chain can also be retained on the spandex molecule, resulting in more dye seats on the spandex molecule. This can be verified by detecting excess amine. The presence of terminal hydroxyl groups enhances the hydrophilicity of spandex, thereby reducing its static electricity. Furthermore, the ratio of hydroxyl to secondary amine groups in the reacted N-(2-hydroxyethyl)ethylenediamine is 1:1, meaning that compared to conventional spandex, the increase in amine groups does not result in greater static electricity. The presence of hydroxyl groups also improves the ability of spandex fibers to absorb reactive dyes, enhancing the dyeing performance when blended with cotton, wool, and other fibers. Further, by using different proportions of the chain extender propylenediamine to adjust the regularity of the hard segment structure of the spandex molecule, the heat resistance of the fiber can be ensured. This allows for the use of acid dyes to color the spandex first, followed by disperse dyes to color the polyester when blending spandex with polyester.

[0007] This invention uses N-(2-hydroxyethyl)ethylenediamine as a terminating agent to introduce equal amounts of secondary amine groups and terminal hydroxyl groups into the molecular chain without altering the main chain structure of spandex. This increases the number of dye sites in the spandex molecule, improves the binding ability of the fiber with acid dyes, reactive dyes, etc., and at the same time improves the hydrophilicity of spandex fiber through the introduction of hydroxyl groups, thereby enhancing the antistatic properties of the fiber.

[0008] The structural formula of N-(2-hydroxyethyl)ethylenediamine is as follows:

[0009] A method for preparing antistatic dyeable spandex fiber includes the following steps: Step 1: Prepolymerization reaction The NCO-terminated prepolymer is obtained by reacting diisocyanate and polyether diol in a molar ratio of (1.5-2.0):1, with a preferred molar ratio of (1.6-1.8):1; The prepolymer is dissolved in a solvent to form a prepolymer solution with a mass percentage concentration of 36-46%; the solvent is dimethylacetamide (DMAC).

[0010] Step 2, chain extension reaction The above prepolymer solution was subjected to a chain extension reaction with a mixed amine solution to obtain a polyurethane urea stock solution with a mass percentage concentration of 34-42%, wherein the molar ratio of terminal amines in the mixed amine solution to NCO in the prepolymer solution was (1.05-1.15):1, and the amine content after the chain extension reaction was 40-80 mmol / kg.

[0011] Step 3, Curing and spinning The polyurethane urea stock solution was matured to form a spinning stock solution, which was then dry-spun to produce antistatic dyeable spandex fibers.

[0012] Furthermore, in the prepolymerization reaction step, the diisocyanate is one or more combinations of 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, hexamethylene diisocyanate, cyclohexanedimethylene diisocyanate, and 4,4'-dicyclohexylmethane diisocyanate.

[0013] Furthermore, the polyether glycol includes one or more combinations of polytetramethylene ether glycol, polyethylene glycol, polypropylene glycol, and poly-2-methyltetrahydrofuran, with a molecular weight of 1500-3000.

[0014] Furthermore, in the chain extension reaction step, the mixed amine solution includes a chain extender, a terminator, a crosslinking agent, and DMAC; the mass percentage concentration of the mixed amine solution ranges from 5-10%, preferably 7%.

[0015] Furthermore, the chain extender is a mixture of ethylenediamine and 1,2-propanediamine, wherein the molar ratio of ethylenediamine to 1,2-propanediamine is (80-100):(20-0).

[0016] Furthermore, the terminating agent is one or more of diethylamine, N,N'-bis(hydroxyethyl)ethylenediamine, N-(2-hydroxyethyl)ethylenediamine, 2-hydroxyethylaminopropylamine, and ethanolamine, preferably N-(2-hydroxyethyl)ethylenediamine, and the molar ratio of chain extender to terminating agent is (6-10):1.

[0017] Furthermore, the polyurethane urea stock solution selectively contains functional additives, including one or more of the following: matting agents, antioxidants, anti-yellowing agents, lubricants, chlorine-resistant agents, dyeing auxiliaries, cohesive agents, and stabilizers.

[0018] Furthermore, the stabilizer is tetramethylpiperidineamine or tetramethylpiperidine alcohol.

[0019] Furthermore, the amount of the functional additives is calculated based on the mass of the obtained spandex fiber, and the amounts are as follows: antioxidant: 0.6-1.2%, matting agent: 0.1-0.5%, lubricant: 0.1-0.5%, dyeing auxiliary agent: 0.5-1.2%, anti-yellowing agent: 0.1-0.5%, chlorine resistant agent: 1-4%, cohesive agent: 0.5-1.5%, and stabilizer: 0.01-0.05%.

[0020] The key point of this invention lies in using N-(2-hydroxyethyl)ethylenediamine as a terminator to replace diethylamine in the chain extension reaction, thereby introducing equal amounts of terminal amine and hydroxyl groups into the spandex molecule, increasing the number of dye sites in the spandex molecule. Combined with the use of stabilizers, this improves the dyeing ability and color fastness of acid dyes and reactive dyes on spandex fibers. Simultaneously, the introduction of terminal hydroxyl groups improves the hydrophilicity of spandex fibers, thereby enhancing antistatic properties during warping and weaving processes, reducing defect rates in subsequent processes, and saving production costs. Based on this main improvement, the chain extension reaction can be further adjusted by using different proportions of 1,2-propanediamine, allowing for the preparation of heat-resistant, antistatic, dyeable spandex fibers through dry spinning.

[0021] The advantages of this invention are: Compared with existing technologies, this invention uses N-(2-hydroxyethyl)ethylenediamine as a chain extension agent in the spandex production process, combined with the use of stabilizers, to prepare antistatic dyeable spandex fibers. This can improve the dyeing rate and color fastness of spandex fibers to acid dyes and reactive dyes. The heat-resistant dyeable spandex can also meet the high-temperature dyeing requirements of the polyester-spandex field. At the same time, the improved antistatic properties of spandex fibers can reduce the amount of oiling agents used by spandex manufacturers, thereby reducing production costs. For subsequent processes, it can reduce the defect rate in dyeing, finishing, and weaving, thus saving costs. Attached Figure Description

[0022] Figure 1 These are microscopic photographs of dyed examples 1-9 (nylon-ammonia interwoven fabric). Detailed Implementation

[0023] To make the above-mentioned features and advantages of the present invention more apparent and understandable, specific embodiments are described below in detail. Unless otherwise specified, the methods of the present invention are conventional methods in the art.

[0024] Comparative Example 1: 4,4'-diphenylmethane diisocyanate at a flow rate of 143.1 g / min and polytetramethylene ether glycol with a molecular weight of 1800 at a flow rate of 610.4 g / min were mixed evenly in a static mixer and heated to 92°C for 4 hours to obtain a prepolymer with NCO-terminated ends. This prepolymer was then mixed with DMAC at a flow rate of 1191.3 g / min using a dissolving machine to prepare a prepolymer solution with a mass percentage concentration of 38.74%. The prepolymer solution was reacted with a mixed amine solution at a flow rate of 232.5 g / min in a second reactor at a reaction temperature of 25-30℃, yielding a polyurethane urea stock solution with a mass percentage concentration of 35.35%. The mixed amine solution had a mass percentage concentration of 7%, wherein the molar ratio of terminal amines to NCO in the prepolymer solution was 1.04, the molar ratio of ethylenediamine to 1,2-propanediamine was 9:1 (chain extender), the molar ratio of chain extender to diethylamine terminator was 7:1, and the crosslinking agent diethylenetriamine was added at 0.02% of the fiber mass. The excess amine content was 24 mmol / kg. After chain extension, the resulting solution was mixed with additives in a buffer tank. The additives were: antioxidant 245 (0.95% of fiber mass), titanium dioxide (0.45% of fiber mass), magnesium stearate (0.35% of fiber mass), dyeing agent (0.9% of fiber mass), cohesive agent (1.1% of fiber mass), anti-yellowing agent (0.4% of fiber mass), and chlorine resistant agent (2% of fiber mass). After the solution was matured, it was dry-spun to prepare conventional spandex fiber with an oil content of 5.5%.

[0025] Example 1: 4,4'-diphenylmethane diisocyanate at a flow rate of 146 g / min and polytetramethylene ether glycol with a molecular weight of 1800 at a flow rate of 607.4 g / min were mixed evenly in a static mixer and heated to 90°C for 4 hours to obtain a NCO-terminated prepolymer. This prepolymer was then dissolved in a solvent with 950.3 g / min of DMAC to form a prepolymer solution with a mass percentage concentration of 44.22%. The prepolymer solution was reacted with a mixed amine solution at a flow rate of 265.5 g / min in a second reactor at a reaction temperature of 25-30℃, yielding a polyurethane urea stock solution with a mass percentage concentration of 39.20%. The mixed amine solution had a mass percentage concentration of 7%, wherein the molar ratio of terminal amines to NCO in the prepolymer solution was 1.10, the molar ratio of ethylenediamine to 1,2-propanediamine was 4:1 (chain extender), the molar ratio of chain extender to N-(2-hydroxyethyl)ethylenediamine (terminator) was 6.4:1, and the amount of crosslinking agent diethylenetriamine added was 0.002% of the fiber mass. Excess amine after the reaction... The content is 65 mmol / kg. After chain extension, the original solution is mixed with additives in a buffer tank. The additives are: antioxidant 245 (0.95% of fiber mass), titanium dioxide (0.45% of fiber mass), magnesium stearate (0.35% of fiber mass), dyeing aid (0.9% of fiber mass), cohesive agent (1.1% of fiber mass), anti-yellowing agent (0.4% of fiber mass), chlorine resistant agent (2% of fiber mass), and stabilizer TAD (0.015% of fiber mass). After the original solution is matured, it is dry spun to prepare antistatic dyeable spandex fiber with an oil content of 4.2%.

[0026] Example 2: 4,4'-diphenylmethane diisocyanate at a flow rate of 142.1 g / min and polytetramethylene ether glycol with a molecular weight of 1800 at a flow rate of 611.3 g / min were mixed evenly in a static mixer and heated to 90°C for 4 hours to obtain a NCO-terminated prepolymer. This prepolymer was then dissolved in a solvent with 966.3 g / min of DMAC to form a prepolymer solution with a mass percentage concentration of 43.81%. The prepolymer solution was reacted with a mixed amine solution at a flow rate of 246.3 g / min in a second reactor at a reaction temperature of 25-30℃, yielding a polyurethane urea stock solution with a mass percentage concentration of 39.20%. The mixed amine solution had a mass percentage concentration of 7%, wherein the molar ratio of terminal amines to NCO in the prepolymer solution was 1.10, the molar ratio of ethylenediamine to 1,2-propanediamine was 4:1 (chain extender), the molar ratio of chain extender to N-(2-hydroxyethyl)ethylenediamine (terminator) was 6.4:1, and the amount of crosslinking agent diethylenetriamine added was 0.002% of the fiber mass. Excess amine after the reaction... The content is 61 mmol / kg. After chain extension, the original solution is mixed with additives in a buffer tank. The additives are: antioxidant 245 (0.95% of fiber mass), titanium dioxide (0.45% of fiber mass), magnesium stearate (0.35% of fiber mass), dyeing aid (0.9% of fiber mass), cohesive agent (1.1% of fiber mass), anti-yellowing agent (0.4% of fiber mass), chlorine resistant agent (2% of fiber mass), and stabilizer TAD (0.015% of fiber mass). After the original solution is matured, it is dry spun to prepare antistatic dyeable spandex fiber with an oil content of 4.0%.

[0027] Example 3: 4,4'-diphenylmethane diisocyanate at a flow rate of 138.1 g / min and polytetramethylene ether glycol with a molecular weight of 1800 at a flow rate of 615.3 g / min were mixed evenly in a static mixer and heated to 90°C for 4 hours to obtain a NCO-terminated prepolymer. This prepolymer was then mixed with DMAC at a flow rate of 981.6 g / min using a dissolving machine to prepare a prepolymer solution with a mass percentage concentration of 43.42%. The prepolymer solution was reacted with a mixed amine solution at a flow rate of 227.6 g / min in a second reactor at a reaction temperature of 25-30℃, yielding a polyurethane urea stock solution with a mass percentage concentration of 39.20%. The mixed amine solution had a mass percentage concentration of 7%, wherein the molar ratio of terminal amines to NCO in the prepolymer solution was 1.10, the molar ratio of ethylenediamine to 1,2-propanediamine was 4:1 (chain extender), the molar ratio of chain extender to N-(2-hydroxyethyl)ethylenediamine (terminator) was 6.4:1, and the amount of crosslinking agent diethylenetriamine added was 0.002% of the fiber mass. Excess amine after the reaction... The content is 58 mmol / kg. After chain extension, the dope solution is mixed with additives in a buffer tank. The additives are: antioxidant 245 (0.95% of fiber mass), titanium dioxide (0.45% of fiber mass), magnesium stearate (0.35% of fiber mass), dyeing aid (0.9% of fiber mass), cohesive agent (1.1% of fiber mass), anti-yellowing agent (0.4% of fiber mass), chlorine resistant agent (2% of fiber mass), and stabilizer TAD (0.015% of fiber mass). After the dope solution is matured, it is dry spun to prepare antistatic dyeable spandex fiber with an oil content of 4.4%.

[0028] Example 4: 4,4'-diphenylmethane diisocyanate at a flow rate of 146 g / min and polytetramethylene ether glycol with a molecular weight of 1800 at a flow rate of 607.4 g / min were mixed evenly in a static mixer and heated to 90°C for 4 hours to obtain a NCO-terminated prepolymer. This prepolymer was then dissolved in a solvent with 1161.2 g / min of DMAC to form a prepolymer solution with a mass percentage concentration of 39.35%. The prepolymer solution was reacted with a mixed amine solution at a flow rate of 258.3 g / min in a second reactor at a reaction temperature of 25-30℃, yielding a polyurethane urea stock solution with a mass percentage concentration of 35.51%. The mixed amine solution had a mass percentage concentration of 7%, wherein the molar ratio of terminal amines to NCO in the prepolymer solution was 1.10, the molar ratio of ethylenediamine to 1,2-propanediamine was 9:1 (chain extender), the molar ratio of chain extender to N-(2-hydroxyethyl)ethylenediamine (terminator) was 7:1, and the amount of crosslinking agent diethylenetriamine added was 0.002% of the fiber mass. The excess amine after the reaction contained... The amount was 63 mmol / kg. After chain extension, the resulting solution was mixed with additives in a buffer tank. The additives were: antioxidant 245 (0.95% of fiber mass), titanium dioxide (0.45% of fiber mass), magnesium stearate (0.35% of fiber mass), dyeing aid (0.9% of fiber mass), cohesive agent (1.1% of fiber mass), anti-yellowing agent (0.4% of fiber mass), chlorine resistant agent (2% of fiber mass), and stabilizer TAD (0.015% of fiber mass). After the solution was matured, it was dry spun to prepare antistatic dyeable spandex fiber with an oil content of 4.0%.

[0029] Example 5: 4,4'-diphenylmethane diisocyanate at a flow rate of 142.1 g / min and polytetramethylene ether glycol with a molecular weight of 1800 at a flow rate of 611.3 g / min were mixed evenly in a static mixer and heated to 90°C for 4 hours to obtain a NCO-terminated prepolymer. This prepolymer was then mixed with DMAC at a flow rate of 1176 g / min using a dissolving machine to prepare a prepolymer solution with a mass percentage concentration of 39.05%. The prepolymer solution was reacted with a mixed amine solution at a flow rate of 239.5 g / min in a second reactor at a reaction temperature of 25-30 °C, yielding a polyurethane urea stock solution with a mass percentage concentration of 35.51%. The mixed amine solution had a mass percentage concentration of 7%, wherein the molar ratio of terminal amines to NCO in the prepolymer solution was 1.10, the molar ratio of ethylenediamine to 1,2-propanediamine was 9:1 (chain extender), the molar ratio of chain extender to N-(2-hydroxyethyl)ethylenediamine (terminator) was 7:1, and the amount of crosslinking agent diethylenetriamine added was 0.002% of the fiber mass. The excess amine after the reaction contained... The amount was 59 mmol / kg. After chain extension, the resulting solution was mixed with additives in a buffer tank. The additives were: antioxidant 245 (0.95% of fiber mass), titanium dioxide (0.45% of fiber mass), magnesium stearate (0.35% of fiber mass), dyeing aid (0.9% of fiber mass), cohesive agent (1.1% of fiber mass), anti-yellowing agent (0.4% of fiber mass), chlorine resistant agent (2% of fiber mass), and stabilizer TAD (0.015% of fiber mass). After the solution was matured, it was dry spun to prepare antistatic dyeable spandex fiber with an oil content of 4.0%.

[0030] Example 6: 4,4'-diphenylmethane diisocyanate at a flow rate of 138.1 g / min and polytetramethylene ether glycol with a molecular weight of 1800 at a flow rate of 615.3 g / min were mixed evenly in a static mixer and heated to 90°C for 4 hours to obtain a NCO-terminated prepolymer. This prepolymer was then dissolved in a solvent with 1189.6 g / min of DMAC to form a prepolymer solution with a mass percentage concentration of 38.78%. The prepolymer solution was reacted with a mixed amine solution at a flow rate of 222.5 g / min in a second reactor at a reaction temperature of 25-30℃, yielding a polyurethane urea stock solution with a mass percentage concentration of 35.51%. The mixed amine solution had a mass percentage concentration of 7%, wherein the molar ratio of terminal amines to NCO in the prepolymer solution was 1.11, the molar ratio of ethylenediamine to 1,2-propanediamine was 9:1 (chain extender), the molar ratio of chain extender to N-(2-hydroxyethyl)ethylenediamine (terminator) was 7:1, and the amount of crosslinking agent diethylenetriamine added was 0.002% of the fiber mass. The excess amine after the reaction contained... The amount was 59 mmol / kg. After chain extension, the resulting solution was mixed with additives in a buffer tank. The additives were: antioxidant 245 (0.95% of fiber mass), titanium dioxide (0.45% of fiber mass), magnesium stearate (0.35% of fiber mass), dyeing aid (0.9% of fiber mass), cohesive agent (1.1% of fiber mass), anti-yellowing agent (0.4% of fiber mass), chlorine resistant agent (2% of fiber mass), and stabilizer TAD (0.015% of fiber mass). After the solution was matured, it was dry spun to prepare antistatic dyeable spandex fiber with an oil content of 4.2%.

[0031] Example 7: 4,4'-diphenylmethane diisocyanate at a flow rate of 146 g / min and polytetramethylene ether glycol with a molecular weight of 1800 at a flow rate of 607.4 g / min were mixed evenly in a static mixer and heated to 90°C for 4 hours to obtain a NCO-terminated prepolymer. This prepolymer was then dissolved in a solvent with 1165.5 g / min of DMAC to form a prepolymer solution with a mass percentage concentration of 39.26%. The prepolymer solution was reacted with a mixed amine solution at a flow rate of 252.2 g / min in a second reactor at a reaction temperature of 25-30 °C, yielding a polyurethane urea stock solution with a mass percentage concentration of 35.52%. The mixed amine solution had a mass percentage concentration of 7%, with a molar ratio of terminal amines to NCO in the prepolymer solution of 1.10, a molar ratio of chain extender ethylenediamine to terminator N-(2-hydroxyethyl)ethylenediamine of 7.5:1, and a crosslinking agent diethylenetriamine added at 0.0015% of the fiber mass. The excess amine content after the reaction was 63 mmol / kJ. g. After chain extension, the original solution is mixed with additives in a buffer tank. The additives are: antioxidant 245 (0.95% of fiber mass), titanium dioxide (0.45% of fiber mass), magnesium stearate (0.35% of fiber mass), dyeing aid (0.9% of fiber mass), cohesive agent (1.1% of fiber mass), anti-yellowing agent (0.4% of fiber mass), chlorine resistant agent (2% of fiber mass), and stabilizer TAD (0.015% of fiber mass). After the original solution is matured, it is dry spun to prepare antistatic dyeable spandex fiber with an oil content of 3.9%.

[0032] Example 8: 4,4'-diphenylmethane diisocyanate at a flow rate of 142.1 g / min and polytetramethylene ether glycol with a molecular weight of 1800 at a flow rate of 611.3 g / min were mixed evenly in a static mixer and heated to 90°C for 4 hours to obtain a NCO-terminated prepolymer. This prepolymer was then dissolved in a solvent with 1178.5 g / min of DMAC to form a prepolymer solution with a mass percentage concentration of 39.00%. The prepolymer solution was reacted with a mixed amine solution at a flow rate of 233.2 g / min in a second reactor at a reaction temperature of 25-30 °C, yielding a polyurethane urea stock solution with a mass percentage concentration of 35.55%. The mixed amine solution had a mass percentage concentration of 7%, with a molar ratio of terminal amines to NCO in the prepolymer solution of 1.09, a molar ratio of chain extender ethylenediamine to terminator N-(2-hydroxyethyl)ethylenediamine of 7.5:1, and a crosslinking agent diethylenetriamine added at 0.0015% of the fiber mass. The excess amine content after the reaction was 57 mmol / kJ. g. After chain extension, the original solution is mixed with additives in a buffer tank. The additives are: antioxidant 245 (0.95% of fiber mass), titanium dioxide (0.45% of fiber mass), magnesium stearate (0.35% of fiber mass), dyeing aid (0.9% of fiber mass), cohesive agent (1.1% of fiber mass), anti-yellowing agent (0.4% of fiber mass), chlorine resistant agent (2% of fiber mass), and stabilizer TAD (0.015% of fiber mass). After the original solution is matured, it is dry spun to prepare antistatic dyeable spandex fiber with an oil content of 4.1%.

[0033] Example 9: 4,4'-diphenylmethane diisocyanate at a flow rate of 138.1 g / min and polytetramethylene ether glycol with a molecular weight of 1800 at a flow rate of 615.3 g / min were mixed evenly in a static mixer and heated to 90°C for 4 hours to obtain a NCO-terminated prepolymer. This prepolymer was then dissolved in a solvent with 1193.6 g / min of DMAC to form a prepolymer solution with a mass percentage concentration of 38.70%. The prepolymer solution was reacted with a mixed amine solution at a flow rate of 214.5 g / min in a second reactor at a reaction temperature of 25-30 °C, yielding a polyurethane urea stock solution with a mass percentage concentration of 35.55%. The mixed amine solution had a mass percentage concentration of 7%, with a molar ratio of terminal amines to NCO in the prepolymer solution of 1.09, a molar ratio of chain extender ethylenediamine to terminator N-(2-hydroxyethyl)ethylenediamine of 7.5:1, and a crosslinking agent diethylenetriamine added at 0.0015% of the fiber mass. The excess amine content after the reaction was 51 mmol / kJ. g. After chain extension, the original solution is mixed with additives in a buffer tank. The additives are: antioxidant 245 (0.95% of fiber mass), titanium dioxide (0.45% of fiber mass), magnesium stearate (0.35% of fiber mass), dyeing aid (0.9% of fiber mass), cohesive agent (1.1% of fiber mass), anti-yellowing agent (0.4% of fiber mass), chlorine resistant agent (2% of fiber mass), and stabilizer TAD (0.015% of fiber mass). After the original solution is matured, it is dry spun to prepare antistatic dyeable spandex fiber with an oil content of 4.4%.

[0034] Performance comparison results of the embodiments and comparative examples of the present invention: 1. Antistatic property testing of fibers: The test sample is tested using an electronic constant tension transmission system with an input roller speed of 100 m / min and an output roller speed of 350 m / min. An electrostatic potential meter is installed at the output roller to measure the generated static electricity.

[0035] 2. Testing the dyeing performance of fibers: The maximum absorbance of the residual liquor before and after dyeing is measured using a UV-Vis spectrophotometer to calculate the dyeing rate. The calculation formula is: Dyeing rate = (A0-A1) / A0×100%, where A0 and A1 are the absorbance of the dye liquor before and after dyeing, respectively.

[0036] 3. Dyeing process conditions: The initial temperature of the dyeing vat is about 40℃, the pH value is 4-5, the dyeing bath ratio is 1:(20-50), select leveling agent and acid release agent as needed, the heating rate is 1.5℃ / min, when the temperature reaches 75℃, keep it at this temperature for 20 minutes, and then continue to heat up to 97℃ at a heating rate of 1.5℃ / min, and keep it at this temperature for about 30 minutes.

[0037] 4. Wash fastness test: The color fastness of the sample to soap washing (or washing) is tested according to GB / T 3921-2008.

[0038] Some dyeing process parameters are shown in Table 1:

[0039] Note: Each dye is a blend of 3 color codes. The content is a percentage of the fabric weight, and the weight column represents the fabric weight.

[0040] Examples 1-9: Dyed photographs (nylon-spandex blend fabric) Figure 1 As shown.

[0041] Table 2 shows the performance comparison results between the embodiments of the present invention and the comparative examples:

[0042] As can be seen from the comparison results in Table 2, the antistatic dyeable spandex fiber prepared by this invention exhibits a decrease in breaking strength but a significant increase in breaking elongation compared to conventional heat-resistant spandex products. The overall strength and elongation properties of the fiber still meet the requirements of major application areas. Compared to the comparative example, the examples, with significantly lower oil content, show a substantial decrease in the static electricity value of the fiber, demonstrating excellent antistatic properties. Furthermore, due to the increased content of terminal amine groups, the fiber's dyeing rate and color fastness to acid dyes are significantly improved. As can be seen from Examples 7, 8, and 9, since 1,2-propanediamine is no longer used as the chain extender, the regularity of the hard segments of the fiber molecular backbone is improved, and the fiber's heat resistance is basically on par with conventional heat-resistant fibers, which can meet the high-temperature dyeing requirements of polyester in the polyester-spandex field.

[0043] The antistatic dyeable spandex prepared by this invention can achieve a color fastness of at least grade 4-5 when interwoven and dyed with six kinds of fibers (nylon, polyester, cotton, wool, acetate and acrylic).

[0044] The above description is only a preferred embodiment of the present invention. All equivalent changes and modifications made within the scope of the claims of the present invention should be included in the scope of the present invention.

Claims

1. A method for preparing antistatic dyeable spandex fiber, characterized in that, Includes the following steps: Step 1: Prepolymerization reaction Diisocyanate and polyether diol were reacted at a molar ratio of (1.5-2.0):1 to obtain NCO-terminated prepolymers; The prepolymer is dissolved in a solvent to form a prepolymer solution with a mass percentage concentration of 36-46%; the solvent is dimethylacetamide (DMAC). Step 2, chain extension reaction The above prepolymer solution was subjected to a chain extension reaction with a mixed amine solution to obtain a polyurethane urea stock solution with a mass percentage concentration of 34-42%, wherein the molar ratio of terminal amines in the mixed amine solution to NCO in the prepolymer solution was (1.05-1.15):1, and the amine content after the chain extension reaction was 40-80 mmol / kg. Step 3, Curing and spinning The polyurethane urea stock solution was matured to form a spinning stock solution, which was then dry-spun to produce antistatic dyeable spandex fibers.

2. The method for preparing antistatic dyeable spandex fiber according to claim 1, characterized in that, In the prepolymerization reaction step, the diisocyanate is one or a combination of 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, hexamethylene diisocyanate, cyclohexanedimethylene diisocyanate, and 4,4'-dicyclohexylmethane diisocyanate.

3. The method for preparing antistatic dyeable spandex fiber according to claim 1, characterized in that, The polyether glycol includes one or more combinations of polytetramethylene ether glycol, polyethylene glycol, polypropylene glycol, and poly-2-methyltetrahydrofuran, with a molecular weight of 1500-3000.

4. The method for preparing antistatic dyeable spandex fiber according to claim 1, characterized in that, In the chain extension reaction step, the mixed amine solution includes a chain extender, a terminator, a crosslinking agent, and DMAC; the mass percentage concentration of the mixed amine solution ranges from 5% to 10%.

5. The method for preparing antistatic dyeable spandex fiber according to claim 4, characterized in that, The chain extender is a mixture of ethylenediamine and 1,2-propanediamine, wherein the molar ratio of ethylenediamine to 1,2-propanediamine is (80-100):(20-0).

6. The method for preparing antistatic dyeable spandex fiber according to claim 4, characterized in that, The terminator is one or more of diethylamine, N,N'-bis(hydroxyethyl)ethylenediamine, N-(2-hydroxyethyl)ethylenediamine, 2-hydroxyethylaminopropylamine, and ethanolamine, with a chain extender to terminator molar ratio of (6-10):

1.

7. The method for preparing antistatic dyeable spandex fiber according to claim 1, characterized in that, The polyurethane urea stock solution contains selectively added functional additives, including one or more of the following: matting agents, antioxidants, anti-yellowing agents, lubricants, chlorine-resistant agents, dyeing auxiliaries, cohesive agents, and stabilizers.

8. The method for preparing antistatic dyeable spandex fiber according to claim 7, characterized in that, The stabilizer is tetramethylpiperidinamine (TAD) or tetramethylpiperidinol (TMP).

9. The method for preparing antistatic dyeable spandex fiber according to claim 7, characterized in that, The amount of the functional additives added is calculated based on the mass of the obtained spandex fibers, and the antioxidants are: 0.6-1.2%, matting agent: 0.1-0.5%, lubricant: 0.1-0.5%, dyeing auxiliary agent: 0.5-1.2%, anti-yellowing agent: 0.1-0.5%, chlorine resistant agent: 1-4%, cohesive agent: 0.5-1.5%, stabilizer: 0.01-0.05%.

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