Preparation method of a dyeing assistant and preparation method of a composite functional spandex

Abstract

The application provides a preparation method of a dyeing assistant and a preparation method of a composite functional spandex, and first prepares an isocyanate modified polyguanidine acid dyeing assistant; dissolves polyguanidine in an alcohol solvent, dissolves isocyanate in a strong polar solvent, slowly drops the isocyanate solution into the polyguanidine solution for mixing to obtain an isocyanate modified polyguanidine solution, and through aging, washing, filtering, purifying and drying, the isocyanate modified polyguanidine acid dyeing assistant is obtained. The application also provides a preparation method of an antibacterial acid-dyeable composite functional spandex, controls the AN ratio to be 1.04-1.07, and adds the isocyanate modified polyguanidine acid dyeing assistant into a polyurethane spinning stock solution to obtain the antibacterial acid-dyeable composite functional spandex fiber with high dyeing rate.

Description

Technical Field

[0001] This invention relates to the field of spandex preparation technology, specifically a method for preparing antibacterial acid-dyeable composite functional spandex, and more particularly to an isocyanate-modified polyguanidine acidic dyeing agent and a method for preparing antibacterial acid-dyeable composite functional spandex using the isocyanate-modified polyguanidine acidic dyeing agent. Background Technology

[0002] Spandex, short for polyurethane elastic fiber, is a chemical fiber with excellent elasticity. Its molecular chain is a long block copolymer with alternating soft and hard chains, possessing excellent elastic elongation and recovery rate; its elongation at break can reach 500%–700%, and when stretched by 300% and cyclically repeated more than 10 times, its elastic recovery rate can still reach over 94%. It is widely used in high-end elastic clothing and hygiene materials, and is an indispensable polymer material in the modern textile industry.

[0003] As the application fields of spandex expand, higher requirements are placed on its performance. In addition to elasticity requirements, different requirements are put forward for spandex according to different uses, such as chlorine resistance, heat resistance, oxidation resistance, antibacterial properties, and ease of dyeing.

[0004] To meet diverse functional requirements, existing technologies often involve adding functional auxiliary solid powders to the spinning solution to obtain functional fibers. For the preparation of ordinary acid-dyeable spandex, the main method involves adding dyeing auxiliaries as auxiliaries to the spinning solution. Some auxiliaries are difficult to dissolve in DMAC and require grinding. The amount of these auxiliaries added is often low; when it exceeds 3% of the solid content of the solution, the powder agglomerates, increasing the particle size and clogging the spinneret during spinning, severely affecting spinning performance. Uneven mixing of auxiliaries in the spinning solution also affects the elongation and breaking strength of the spandex. Furthermore, due to the limited amount of dyeing auxiliaries added, the improvement in color depth of dyeable spandex is limited.

[0005] Patent publication document (CN113045726A) discloses a polyguanidine modified isocyanate prepolymer, which is prepared by the following method: (S1) dissolving polyhexamethylene biguanide hydrochloride in polyether polyol to obtain a mixture; (S2) adding the mixture obtained in step (S1) dropwise to isocyanate under heating and stirring conditions, and continuing to react at a constant temperature for a period of time after the addition is complete. After cooling, the polyguanidine modified isocyanate prepolymer is obtained.

[0006] The patent disclosure describes a method for modifying polyguanidine by adding isocyanate to a mixture of polyguanidine and polyether. The polyether used is a polyether polyol polymerized from ethylene oxide and propylene oxide, with a functionality of 3-4 and a molecular weight of 500-1000. The composite amine catalyst used is dimethylethanolamine or triethylenediamine. The patent disclosure employs a method of inserting polyguanidine blocks into the polyether molecular chain and using isocyanate for linkage. While this technique promotes stronger molecular linkages, the excipient blocking process is uncontrollable and not homopolymerized. Blocking may occur in the first half or the second half of the molecular chain, resulting in uneven mixing. This can lead to uneven dyeing, dye aggregation, and dyeing defects. Summary of the Invention

[0007] To address the problems existing in the prior art, this invention proposes a method for preparing antibacterial, acid-dyeable composite functional spandex using isocyanate-modified polyguanidine acidic dyeing auxiliaries. This invention first provides a method for preparing isocyanate-modified polyguanidine acidic dyeing auxiliaries, comprising:

[0008] Solution A is obtained by dissolving polyguanidine in an alcohol solvent; solution B is obtained by dissolving isocyanate in a strongly polar solvent; wherein the polyguanidine is one or a mixture of polyhexamethylene biguanide or polyhexamethylene biguanide hydrochloride, polyhexylguanidine or polyhexylguanidine hydrochloride, polyaminopropyl biguanide or polyaminopropyl biguanide hydrochloride; the alcohol solvent is one or a mixture of methanol, ethanol, propanol, and butanol; the isocyanate is one of toluene diisocyanate, 4,4-diphenylmethane diisocyanate, and hexamethylene diisocyanate; and the strongly polar solvent is one or a mixture of DMAC, DMSO, and DMF.

[0009] Slowly add solution B dropwise to solution A and mix. Once the predetermined amount of solution B has been added, solution C is obtained.

[0010] Continue stirring the C solution to allow it to mature. Then, distill the matured C solution in stages to remove the organic solvent, thereby obtaining isocyanate-modified polyguanidine solid.

[0011] The obtained isocyanate-modified polyguanidine solid was washed, filtered, and purified by adding deionized water. After purification, it was dried to obtain isocyanate-modified polyguanidine acidic dyeing agent.

[0012] This invention also provides a method for preparing antibacterial acid-dyeable composite functional spandex using isocyanate-modified polyguanidine acid dyeing auxiliaries obtained by the above method, comprising:

[0013] S1. Polytetramethylene ether glycol and 4,4-diphenylmethane diisocyanate are mixed for prepolymerization. After the prepolymerization reaction is completed, the prepolymer product is cooled down and then DMAC solvent is added and stirred until fully dissolved to obtain a prepolymer solution.

[0014] S2. Add a mixed amine solution dissolved in DMAC to the obtained prepolymer solution to carry out chain extension and termination reactions, controlling the AN ratio to be 1.04–1.07, to obtain a chain-extended polyurethane polymer solution. The chain extender for the chain extension reaction is ethylenediamine, propylenediamine, pentanediamine, or a mixture thereof, and the terminator for terminating the reaction is diethylamine. The molar ratio of chain extender to DMAC is 0.04–0.17:1.

[0015] S3. Add auxiliary materials and isocyanate-modified polyguanidine acid dyeing agent to the extended polyurethane polymer solution and stir to mature to obtain spinning solution.

[0016] S4. Dry spinning is performed on the matured spinning solution to obtain spandex with antibacterial and acid-dyeable composite functions.

[0017] In step S3, there are two ways to add the auxiliary materials and isocyanate-modified polyguanidine acid dyeing auxiliaries. The first method is:

[0018] Isocyanate-modified polyguanidine acid dyeing agent, auxiliary materials and DMAC were mixed and ground at a mass ratio of 0-0.2:0.04-0.58:1. The resulting solution was used as the auxiliary material solution in the spinning solution.

[0019] The excipient solution and the chain-extended polyurethane polymer solution are thoroughly mixed at a mass ratio of 0.01 to 0.4:1 and then allowed to mature.

[0020] The second type is:

[0021] The auxiliary materials and DMAC were mixed and ground at a mass ratio of 0.08 to 0.96:1. The resulting solution was used as the auxiliary material solution in the spinning dope.

[0022] Isocyanate-modified polyguanidine acid dyeing agent is dissolved in DMAC to prepare a solution with a concentration of 10.00% to 40.00%, which is used as the modification solution.

[0023] First, mix and mature the excipient solution with the chain-extended polyurethane polymer solution. After mixing evenly, add the modification solution and mix and mature thoroughly again.

[0024] The mass ratio of the excipient solution, the modified solution, and the polyurethane polymer solution is 0.03–0.15:0.01–0.13:3.

[0025] The beneficial effects of this application are as follows:

[0026] 1. In preparing the isocyanate-modified polyguanidine acidic auxiliary dye, this application first dissolves polyguanidine in an alcohol solvent to obtain a polyguanidine solution, and then dissolves isocyanate in a strongly polar solvent to obtain an isocyanate solution. The isocyanate solution is then slowly added dropwise to the polyguanidine solution and mixed to obtain an isocyanate-modified polyguanidine solution. The mixture is then stirred to allow it to mature. The matured isocyanate-modified polyguanidine solution is then fractionally distilled to remove the organic solvent, yielding an isocyanate-modified polyguanidine solid. The obtained isocyanate-modified polyguanidine solid is washed, filtered, and purified with deionized water. After purification, it is dried to obtain the isocyanate-modified polyguanidine acidic auxiliary dye. This application achieves better dissolution at low temperatures by separately preparing the polyguanidine solution and the isocyanate solution, and then mixing them. The resulting isocyanate-modified polyguanidine exhibits good uniformity.

[0027] 2. The secondary amines and other nitrogen-containing groups in isocyanate-modified polyguanidine acidic dyeing auxiliaries act as active sites for dyeing. They chemically react with acid dyes, and uneven mixing can lead to uneven dyeing, dye aggregation, and dyeing defects. This application controls the AN ratio to be 1.04–1.07, that is, the molar ratio of amine groups in the chain extender to the remaining -NCO groups in the prepolymer is 1.04–1.07. This ensures that there is excess amine during the chain extension reaction, consuming the excess active groups in the isocyanate. This avoids the reaction between polyurethane and isocyanate-modified polyguanidine acidic dyeing auxiliaries, thereby obtaining spandex fibers with high dyeing rate and good dyeing uniformity.

[0028] 3. In this application, the isocyanate-modified polyguanidine acidic dyeing auxiliary agent can be added in two ways. The first method is to grind the acidic dyeing auxiliary agent together with other auxiliary materials used in the normal production of spandex and then add it to the polymerization solution for mixing and maturation. The second method is to first grind the other auxiliary materials and add them to the chain-extended polyurethane polymer solution for mixing and maturation, then dissolve the isocyanate-modified polyguanidine acidic dyeing auxiliary agent in a DMAC solution and mix and mature it with the previously matured spinning solution. Both methods can achieve uniform addition of the dyeing auxiliary agent.

[0029] 4. The isocyanate-modified polyguanidine acidic dyeing agent used in this invention is a polycationic compound. It is in a fully protonated state in a normal physiological environment and can maintain a positive charge over a wide pH range. It can adsorb negatively charged bacteria and fungi. By acting on the cell wall and cytoplasm membrane system of bacteria and fungi, it binds to fatty acids in the cell membrane phospholipids, rapidly breaks through their cytoplasmic membranes, and attacks the core of the pathogenic cells, causing the vital substances inside the pathogens to flow out, thereby achieving the best bactericidal effect.

[0030] 5. Polyguanidine antibacterial agents have good water solubility, but poor solubility in the polar solvent DMAC. Therefore, chemical modification is needed to improve the solubility of polyguanidine antibacterial agents in DMAC. The isocyanate-modified polyguanidine acidic dyeing auxiliary agent of this invention has good compatibility with spandex raw materials and good biocompatibility. Because this acidic dyeing auxiliary agent contains a large number of amino cations, it can serve as coloring sites for acid dyes, thereby improving the dyeing performance of fibers. Therefore, this acidic dyeing auxiliary agent has both antibacterial and dyeing auxiliary functions.

[0031] 6. The isocyanate-modified polyguanidine acidic dyeing agent of the present invention can be completely dissolved in DMAC, but is almost insoluble in water. It has good binding properties with spandex spinning dope and will not cause agglomeration. The addition amount is 0.10%-10.00% of the total solid content of the yarn cake. The specific amount used can be determined by formulating according to the color depth requirements. It has little impact on the spinning workability of the spinning dope. The addition of this antibacterial agent does not affect the physical properties of the finished spandex yarn. Detailed Implementation

[0032] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0033] This invention first discloses a method for preparing an isocyanate-modified polyguanidine acidic dyeing agent, comprising:

[0034] Polyguanidine is dissolved in an alcohol solvent to obtain solution A; isocyanate is dissolved in a strongly polar solvent to obtain solution B;

[0035] Slowly add solution B dropwise to solution A and mix. Once the predetermined amount of solution B has been added, solution C is obtained.

[0036] Continue stirring the C solution to allow it to mature. Then, distill the matured C solution in stages to remove the organic solvent, thereby obtaining isocyanate-modified polyguanidine solid.

[0037] The obtained isocyanate-modified polyguanidine solid was washed, filtered, and purified by adding deionized water. After purification, it was dried to obtain isocyanate-modified polyguanidine acidic dyeing agent.

[0038] According to the present invention, solution A and solution B are first prepared. Specifically, polyguanidine is dissolved in an alcohol solvent to obtain solution A; isocyanate is dissolved in a strongly polar solvent to obtain solution B with a mass concentration of [missing information].

[0039] In this invention, the polyguanidine can be selected as one or a mixture of polyhexamethylene biguanide or polyhexamethylene biguanide hydrochloride, polyhexylguanidine or polyhexylguanidine hydrochloride, polyaminopropyl biguanide or polyaminopropyl biguanide hydrochloride; the alcohol solvent can be selected as one or a mixture of methanol, ethanol, propanol, butanol; the isocyanate can be selected as toluene diisocyanate, 4,4-diphenylmethane diisocyanate, hexamethylene diisocyanate; and the highly polar solvent can be selected as one or a mixture of DMAC, DMSO, DMF.

[0040] In this invention, the mass concentration of solution A can be selected to be 5% to 50%, and the mass concentration of solution B can be selected to be 5% to 50%.

[0041] After preparing solutions A and B according to the present invention, solution B is slowly added dropwise to solution A to obtain solution C. Under the optional control conditions of the present invention, solution B is slowly added dropwise to solution A at a rate of 5 ml / min to 20 ml / min, while maintaining a stirring speed of 50 RPM to 100 RPM, a temperature of 30°C to 40°C, and a molar ratio of polyguanidine to isocyanate of 1:1 to 1:3.

[0042] According to the present invention, after obtaining solution C, the solution C is aged and organic matter is removed to obtain isocyanate-modified polyguanidine solid. In the optional control and regulation of the present invention, the aging temperature is controlled at 30℃~40℃, and the aging time is 1h~3h.

[0043] In the above-described control conditions and parameters of the present invention, those skilled in the art can select appropriate control conditions and parameters based on the preparation of the target substance and the preparation environment.

[0044] This invention also provides a method for preparing an antibacterial acid-dyeable composite functional spandex, and an isocyanate-modified polyguanidine acid dyeing agent prepared using the above method, comprising:

[0045] S1. Polytetramethylene ether glycol and 4,4-diphenylmethane diisocyanate are mixed for prepolymerization. After the prepolymerization reaction is completed, the prepolymer product is cooled down and then DMAC solvent is added and stirred until fully dissolved to obtain a prepolymer solution.

[0046] S2. Add a mixed amine solution dissolved in DMAC to the obtained prepolymer solution to carry out chain extension and termination reaction, and control the AN ratio to be 1.04-1.07 to obtain a chain-extended polyurethane polymer solution. The molar ratio of chain extender to DMAC is 0.04-0.17:1.

[0047] S3. Add auxiliary materials and isocyanate-modified polyguanidine acidic dyeing agent to the extended polyurethane polymer solution and stir to mature. There are two ways to add the isocyanate-modified polyguanidine acidic dyeing agent. One way is to mix and grind the isocyanate-modified polyguanidine acidic dyeing agent, auxiliary materials and DMAC at a mass ratio of 0-0.2:0.04-0.58:1. The solution after grinding is used as the auxiliary material solution in the spinning solution. The auxiliary material solution is then thoroughly mixed with the extended polyurethane polymer solution at a mass ratio of 0.01-0.4:1 and matured.

[0048] Another method involves mixing and grinding the auxiliary material with DMAC at a mass ratio of 0.08–0.96:1, and using the resulting solution as the auxiliary material solution in the spinning dosing. An isocyanate-modified polyguanidine acid dyeing agent is dissolved in DMAC to prepare a 10.00%–40.00% solution, which serves as the modification solution. The auxiliary material solution is first mixed with the chain-extended polyurethane polymer solution and allowed to mature. After thorough mixing, the modification solution is added, and the mixture is mixed and matured again. The mass ratio of auxiliary material solution: modification solution: polyurethane polymer solution is 0.03–0.15:0.01–0.13:3.

[0049] S4. Dry spinning is performed on the matured spinning solution to obtain spandex with antibacterial and acid-dyeable composite functions.

[0050] According to the present invention, in preparing antibacterial acid-dyeable composite functional spandex, a prepolymer solution is first prepared. In an optional embodiment, the polytetramethylene ether glycol is selected from polytetramethylene ether glycol with a conventional molecular weight of 1800-2000. The polytetramethylene ether glycol and 4,4-diphenylmethane diisocyanate can be mixed in a molar ratio of 1:1.3-2.0. Under optional reaction control conditions of the prepolymer, the reactants are subjected to a prepolymerization reaction under high-speed stirring at 70°C-90°C for 30-90 minutes. After the prepolymerization reaction is completed, the prepolymer product is cooled to 30°C-40°C.

[0051] According to the present invention, after the prepolymerization reaction is completed, a chain extension reaction and a termination reaction are carried out. In order to completely consume the amine in the prepolymer, the present invention uses an excess of mixed amine and controls the AN ratio to be 1.04 to 1.07, so that there are no excess amine groups in the obtained polyurethane molecules, and avoids the reaction of amine groups with isocyanate-modified polyguanidine acid dyeing agent.

[0052] According to the present invention, after the chain extension reaction is completed, the polyurethane polymer solution after chain extension is added with auxiliary materials and isocyanate-modified polyguanidine acid dyeing agent and then cured for a curing time of 10h to 40h.

[0053] According to the present invention, after curing, spinning can yield spandex with antibacterial and acid-dyeable composite functions.

[0054] In the above control conditions and parameters of the present invention, the process parameter control and reaction condition control of steps S1 and S4 are conventional choices in the art. The proportions of different types of mixed amines added in S2, the addition of other auxiliary materials other than isocyanate-modified polyguanidine acid dyeing agents in S3, and the proportions between the auxiliary materials are also conventional choices. Those skilled in the art can select appropriate control conditions and parameters according to the target substance being prepared and the preparation environment.

[0055] The technical solution and effects of the present invention will be illustrated below through specific embodiments.

[0056] Example 1

[0057] Preparation of isocyanate-modified polyguanidine acidic dyeing auxiliaries - isocyanate-modified polyurethane propyl biguanide dyeing auxiliaries:

[0058] 1.0 kg of polyurethane biguanide was dissolved in 4.0 kg of anhydrous ethanol solvent and stirred to obtain solution A with a mass concentration of 20%; 1.2 kg of 4,4-diphenylmethane diisocyanate was dissolved in 3.8 kg of DMAC solvent to obtain solution B with a mass concentration of 24%.

[0059] Slowly add solution B dropwise to solution A at a rate of 10 ml / min while mixing, keeping the stirring speed at 80 R / min and the temperature within the range of 35 ± 2℃; after adding solution B to the predetermined amount, solution C is obtained.

[0060] The aging temperature was controlled at 35℃±5℃, and the C solution was stirred for 3 hours. The aging solution was then subjected to fractional distillation to remove the organic solvent, yielding isocyanate-modified polyurethane biguanide solid.

[0061] The obtained isocyanate-modified polyurethane biguanide solid was washed with deionized water, filtered, and purified; the purified solid was dried to obtain isocyanate-modified polyurethane biguanide acidic dyeing agent.

[0062] The method for preparing antibacterial acid-dyeable composite functional spandex using the isocyanate-modified polyguanidine dyeing agent obtained by the above preparation method is as follows:

[0063] S1. Mix 100 kg of polytetramethylene ether glycol with a molecular weight of 1800 with 26 kg of 4,4-diphenylmethane diisocyanate and carry out a prepolymerization reaction under high-speed stirring at 70°C for 90 min. After the reaction is completed, cool the prepolymer product to 35°C ± 5°C, and then add 190 kg of DMAC solvent and stir until fully dissolved to obtain a prepolymer solution.

[0064] S2. Add a mixed amine solution, consisting of 2.4 kg ethylenediamine, 0.19 kg propylenediamine, 0.76 kg pentanediamine, and 0.31 kg diethylamine dissolved in 46 kg DMAC, to the prepolymer solution to carry out chain extension and termination reactions, and obtain a chain-extended polyurethane polymer solution. In this step, the AN ratio is 1.05:1.

[0065] S3. Mix 0.4 kg of the above-mentioned isocyanate-modified polyurethane biguanide acid dyeing agent, 3 kg of zinc oxide, 0.86 kg of titanium dioxide, 0.5 kg of anti-yellowing agent, 0.3 kg of antioxidant and 13.6 kg of DMAC and put them into the grinding system. Grind for 55 h. The solution after grinding is used as the auxiliary solution in the spinning dope.

[0066] S4. The auxiliary solution is thoroughly mixed and matured with the chain-extended polyurethane polymer solution for 20 hours. The matured spinning solution is then spun by dry spinning to obtain spandex fiber with antibacterial and acid-dyeable composite functions.

[0067] Example 2

[0068] Preparation of isocyanate-modified polyguanidine acidic dyeing auxiliaries - isocyanate-modified polyurethane propyl biguanide dyeing auxiliaries:

[0069] 1.0 kg of polyurethane biguanide was dissolved in 1 kg of methanol solvent and stirred to obtain solution A with a mass concentration of 50%; 1.2 kg of 4,4-diphenylmethane diisocyanate was dissolved in 1.2 kg of DMF solvent to obtain solution B with a mass concentration of 50%.

[0070] Slowly add solution B dropwise to solution A at a rate of 5 ml / min while mixing, keeping the stirring speed at 50 RPM and the temperature within the range of 38 ± 2℃; after adding solution B to the predetermined amount, solution C is obtained.

[0071] The aging temperature was controlled at 35℃±5℃, and the C solution was stirred for 3 hours. The aging solution was then subjected to fractional distillation to remove the organic solvent, yielding isocyanate-modified polyurethane biguanide solid.

[0072] The obtained isocyanate-modified polyurethane biguanide solid was washed with deionized water, filtered, and purified; the purified solid was dried to obtain isocyanate-modified polyurethane biguanide acidic dyeing agent.

[0073] The method for preparing antibacterial acid-dyeable composite functional spandex using the isocyanate-modified polyguanidine dyeing agent obtained by the above preparation method is as follows:

[0074] S1. Mix 100 kg of polytetramethylene ether glycol with a molecular weight of 1800 with 26 kg of 4,4-diphenylmethane diisocyanate and carry out a prepolymerization reaction under high-speed stirring at 80°C for 70 min. After the reaction, cool the prepolymer product to 35°C ± 5°C and then add 190 kg of DMAC solvent and stir until fully dissolved to obtain a prepolymer solution.

[0075] S2. Add a mixed amine solution, consisting of 2.4 kg ethylenediamine, 0.19 kg propylenediamine, 0.76 kg pentanediamine, and 0.31 kg diethylamine dissolved in 46 kg DMAC, to the prepolymer solution to carry out chain extension and termination reactions, and obtain a chain-extended polyurethane polymer solution. In this step, the AN ratio is 1.05:1.

[0076] S3. Mix 3.0 kg zinc oxide, 0.86 kg titanium dioxide, 0.5 kg anti-yellowing agent, 0.3 kg antioxidant and 10 kg DMAC and put them into the grinding system. Grind for 5 hours. The solution after grinding is used as the auxiliary material solution in the spinning solution.

[0077] The excipient solution and the chain-extended polyurethane polymer solution were thoroughly mixed and matured for 5 hours.

[0078] Dissolve 0.4 kg of the above isocyanate-modified polyurethane biguanide acidic dyeing agent in 3.6 kg of DMAC to prepare a 10% modified solution.

[0079] S4. Mix the modified solution with the auxiliary solution, and allow it to fully mix and mature for 15 hours. The matured spinning solution is then spun using dry spinning to obtain spandex fiber with antibacterial and acid-dyeable composite functions.

[0080] Example 3

[0081] Preparation of isocyanate-modified polyguanidine acidic dyeing auxiliaries - isocyanate-modified polyhexylguanidine dyeing auxiliaries:

[0082] 1.0 kg of polyhexylguanidine was dissolved in 19 kg of propanol solvent and stirred to obtain a 5% (w / w) solution A; 1.2 kg of hexamethylene diisocyanate was dissolved in 22.8 kg of DMSO solvent to obtain a 5% (w / w) solution B.

[0083] Slowly add solution B dropwise to solution A at a rate of 20 ml / min while mixing, keeping the stirring speed at 100 R / min and the temperature within the range of 30 ± 2℃; after adding solution B to the predetermined amount, solution C is obtained.

[0084] The temperature was controlled at 35℃±5℃, and the C solution was stirred for 1 hour to mature. The matured solution was then subjected to fractional distillation to remove the organic solvent, yielding isocyanate-modified polyhexylguanidine solid.

[0085] The obtained isocyanate-modified polyhexylguanidine solid was washed with deionized water, filtered and purified; the purified solid was dried to obtain isocyanate-modified polyhexylguanidine acidic dyeing agent.

[0086] The method for preparing antibacterial, acid-dyeable composite functional spandex using the isocyanate-modified polyhexyl guanidine acid dyeing auxiliary agent obtained by the above preparation method is as follows:

[0087] S1. Mix 100 kg of polytetramethylene ether glycol with a molecular weight of 1800 with 26 kg of 4,4-diphenylmethane diisocyanate and carry out a prepolymerization reaction under high-speed stirring at 90°C for 30 min. After the reaction, cool the prepolymer product to 35°C ± 5°C and then add 190 kg of DMAC solvent and stir until fully dissolved to obtain a prepolymer solution.

[0088] S2. Add a mixed amine solution, consisting of 2.4 kg ethylenediamine, 0.19 kg propylenediamine, 0.76 kg pentanediamine, and 0.31 kg diethylamine dissolved in 46 kg DMAC, to the prepolymer solution to carry out chain extension and termination reactions, and obtain a chain-extended polyurethane polymer solution. In this step, the AN ratio is 1.05:1.

[0089] S3. Mix 0.7 kg of the above isocyanate-modified polyhexyl guanidine acid dyeing agent, 3 kg of zinc oxide, 0.86 kg of titanium dioxide, 0.5 kg of anti-yellowing agent, 0.3 kg of antioxidant and 13.6 kg of DMAC and put them into the grinding system. Grind for 55 h. The solution after grinding is used as the auxiliary solution in the spinning dope.

[0090] S4. Mix the modified solution with the auxiliary solution, and allow it to fully mix and mature for 15 hours. The matured spinning solution is then spun using dry spinning to obtain spandex fiber with antibacterial and acid-dyeable composite functions.

[0091] Example 4

[0092] Preparation of isocyanate-modified polyguanidine acidic dyeing auxiliary agent - isocyanate-modified polyguanidine is a polyhexamethylene biguanide dyeing auxiliary agent:

[0093] 1.0 kg of polyguanidine (polyhexamethylene biguanide) was dissolved in 4 kg of butanol solvent and stirred to obtain solution A with a mass concentration of 20%; 1.2 kg of toluene diisocyanate was dissolved in 4.8 kg of DMAC solvent to obtain solution B with a mass concentration of 20%.

[0094] Slowly add solution B dropwise to solution A at a rate of 10 ml / min while mixing, keeping the stirring speed at 80 R / min and the temperature within the range of 30 ± 2℃; after adding solution B to the predetermined amount, solution C is obtained.

[0095] The aging temperature was controlled at 35℃±5℃, and the C solution was stirred for 3 hours. The aging solution was then subjected to fractional distillation to remove the organic solvent, yielding isocyanate-modified polyhexamethylene biguanide solid.

[0096] The obtained isocyanate-modified polyhexamethylene biguanide solid was washed with deionized water, filtered, and purified; the purified solid was dried to obtain isocyanate-modified polyhexamethylene biguanide acidic dyeing agent.

[0097] The method for preparing antibacterial acid-dyeable composite functional spandex using the isocyanate-modified polyguanidine dyeing agent obtained by the above preparation method is as follows:

[0098] S1. Mix 100 kg of polytetramethylene ether glycol with a molecular weight of 1800 with 26 kg of 4,4-diphenylmethane diisocyanate and carry out a prepolymerization reaction under high-speed stirring at 90°C for 30 min. After the reaction, cool the prepolymer product to 35°C ± 5°C and then add 190 kg of DMAC solvent and stir until fully dissolved to obtain a prepolymer solution.

[0099] S2. Add a mixed amine solution, consisting of 2.4 kg ethylenediamine, 0.19 kg propylenediamine, 0.76 kg pentanediamine, and 0.31 kg diethylamine dissolved in 46 kg DMAC, to the prepolymer solution to carry out chain extension and termination reactions, and obtain a chain-extended polyurethane polymer solution. In this step, the AN ratio is 1.05:1.

[0100] S3. Mix 3.0 kg zinc oxide, 0.86 kg titanium dioxide, 0.5 kg anti-yellowing agent, 0.3 kg antioxidant and 10 kg DMAC and put them into the grinding system. Grind for 5 hours. The solution after grinding is used as the auxiliary material solution in the spinning solution.

[0101] The excipient solution and the chain-extended polyurethane polymer solution were thoroughly mixed and matured for 5 hours.

[0102] Dissolve 1.4 kg of the above isocyanate-modified polyhexyl guanidine acid dyeing agent in 3.6 kg of DMAC to prepare a modified solution with a concentration of 28%.

[0103] S4. Mix the modified solution with the auxiliary solution, and allow it to fully mix and mature for 15 hours. The matured spinning solution is then spun using dry spinning to obtain spandex fiber with antibacterial and acid-dyeable composite functions.

[0104] Example 5

[0105] Preparation of isocyanate-modified polyguanidine acidic dyeing auxiliary agent - isocyanate-modified polyguanidine is a polyhexamethylene biguanide dyeing auxiliary agent:

[0106] 1.0 kg of polyurethane biguanide hydrochloride was dissolved in 4 kg of anhydrous ethanol solvent and stirred to obtain solution A with a mass concentration of 20%; 1.2 kg of 4,4-diphenylmethane diisocyanate was dissolved in 4.8 kg of DMAC solvent to obtain solution B with a mass concentration of 20%.

[0107] Slowly add solution B dropwise to solution A at a rate of 10 ml / min while mixing, keeping the stirring speed at 80 R / min and the temperature within the range of 30 ± 2℃; after adding solution B to the predetermined amount, solution C is obtained.

[0108] The aging temperature was controlled at 35℃±5℃, and the C solution was stirred for 3 hours. The aging solution was then subjected to fractional distillation to remove the organic solvent, yielding isocyanate-modified polyhexamethylene biguanide solid.

[0109] The obtained isocyanate-modified polyhexamethylene biguanide solid was washed with deionized water, filtered, and purified; the purified solid was dried to obtain isocyanate-modified polyurethane biguanide acidic dyeing agent.

[0110] The method for preparing antibacterial acid-dyeable composite functional spandex using the isocyanate-modified polyguanidine dyeing agent obtained by the above preparation method is as follows:

[0111] S1. Mix 100 kg of polytetramethylene ether glycol with a molecular weight of 1800 with 26 kg of 4,4-diphenylmethane diisocyanate and carry out a prepolymerization reaction under high-speed stirring at 90°C for 30 min. After the reaction, cool the prepolymer product to 35°C ± 5°C and then add 190 kg of DMAC solvent and stir until fully dissolved to obtain a prepolymer solution.

[0112] S2. Add a mixed amine solution, consisting of 2.4 kg ethylenediamine, 0.19 kg propylenediamine, 0.76 kg pentanediamine, and 0.31 kg diethylamine dissolved in 46 kg DMAC, to the prepolymer solution to carry out chain extension and termination reactions, and obtain a chain-extended polyurethane polymer solution. In this step, the AN ratio is 1.05:1.

[0113] S3. Mix 3.0 kg zinc oxide, 0.86 kg titanium dioxide, 0.5 kg anti-yellowing agent, 0.3 kg antioxidant and 10 kg DMAC and put them into the grinding system. Grind for 5 hours. The solution after grinding is used as the auxiliary material solution in the spinning solution.

[0114] The excipient solution and the chain-extended polyurethane polymer solution were thoroughly mixed and matured for 5 hours.

[0115] Dissolve 2.8 kg of the above isocyanate-modified polyhexamethylene biguanide acidic dyeing agent in 5.0 kg of DMAC to prepare a modified solution with a concentration of 36%.

[0116] S4. Mix the modified solution with the auxiliary solution, and allow it to fully mix and mature for 15 hours. The matured spinning solution is then spun using dry spinning to obtain spandex fiber with antibacterial and acid-dyeable composite functions.

[0117] Example 6

[0118] Preparation of isocyanate-modified polyguanidine acidic dyeing auxiliaries - isocyanate-modified polyhexamethylene biguanide dyeing auxiliaries:

[0119] 1.0 kg of polyhexamethylene biguanide hydrochloride was dissolved in 4.0 kg of anhydrous ethanol solvent and stirred to obtain solution A with a mass concentration of 20%; 1.2 kg of 4,4-diphenylmethane diisocyanate was dissolved in 3.8 kg of DMAC solvent to obtain solution B with a mass concentration of 20%.

[0120] Slowly add solution B dropwise to solution A at a rate of 10 ml / min while mixing, keeping the stirring speed at 80 R / min and the temperature within the range of 35 ± 2℃; after adding solution B to the predetermined amount, solution C is obtained.

[0121] The aging temperature was controlled at 35℃±5℃, and the C solution was stirred for 3 hours. The aging solution was then subjected to fractional distillation to remove the organic solvent, yielding isocyanate-modified polyhexamethylene biguanide solid.

[0122] The obtained isocyanate-modified polyhexamethylene biguanide solid was washed with deionized water, filtered, and purified; the purified solid was dried to obtain isocyanate-modified polyhexamethylene biguanide acidic dyeing agent.

[0123] The method for preparing antibacterial acid-dyeable composite functional spandex using the isocyanate-modified polyguanidine dyeing agent obtained by the above preparation method is as follows:

[0124] S1. Mix 100 kg of polytetramethylene ether glycol with a molecular weight of 1800 with 26 kg of 4,4-diphenylmethane diisocyanate and carry out a prepolymerization reaction under high-speed stirring at 90°C for 30 min. After the reaction, cool the prepolymer product to 35°C ± 5°C and then add 190 kg of DMAC solvent and stir until fully dissolved to obtain a prepolymer solution.

[0125] S2. Add a mixed amine solution, consisting of 2.4 kg ethylenediamine, 0.19 kg propylenediamine, 0.76 kg pentanediamine, and 0.31 kg diethylamine dissolved in 46 kg DMAC, to the prepolymer solution to carry out chain extension and termination reactions, and obtain a chain-extended polyurethane polymer solution. In this step, the AN ratio is 1.05:1.

[0126] S3. Mix 2.8 kg of the above-mentioned isocyanate-modified polyhexamethylene biguanide acidic dyeing agent, 3 kg of zinc oxide, 0.86 kg of titanium dioxide, 0.5 kg of anti-yellowing agent, 0.3 kg of antioxidant and 15 kg of DMAC and put them into the grinding system. Grind for 55 h. The solution after grinding is used as the auxiliary solution in the spinning solution.

[0127] S4. Mix the modified solution with the auxiliary solution, and allow it to fully mix and mature for 15 hours. The matured spinning solution is then spun using dry spinning to obtain spandex fiber with antibacterial and acid-dyeable composite functions.

[0128] Example 7

[0129] Preparation of isocyanate-modified polyguanidine acidic dyeing auxiliaries - isocyanate-modified polyhexylguanidine dyeing auxiliaries:

[0130] 1.0 kg of polyhexyl guanidine hydrochloride was dissolved in 4.0 kg of anhydrous ethanol solvent and stirred to obtain solution A with a mass concentration of 20%; 1.2 kg of 4,4-diphenylmethane diisocyanate was dissolved in 3.8 kg of DMAC solvent to obtain solution B with a mass concentration of 20%.

[0131] Slowly add solution B dropwise to solution A at a rate of 10 ml / min while mixing, keeping the stirring speed at 80 R / min and the temperature within the range of 35 ± 2℃; after adding solution B to the predetermined amount, solution C is obtained.

[0132] The aging temperature was controlled at 35℃±5℃, and the C solution was stirred for 3 hours. The aging solution was then subjected to fractional distillation to remove the organic solvent, yielding isocyanate-modified polyhexylguanidine solid.

[0133] The obtained isocyanate-modified polyhexylguanidine solid was washed with deionized water, filtered and purified; the purified solid was dried to obtain isocyanate-modified polyhexylguanidine acidic dyeing agent.

[0134] The method for preparing antibacterial acid-dyeable composite functional spandex using the isocyanate-modified polyguanidine dyeing agent obtained by the above preparation method is as follows:

[0135] S1. Mix 100 kg of polytetramethylene ether glycol with a molecular weight of 1800 with 26 kg of 4,4-diphenylmethane diisocyanate and carry out a prepolymerization reaction under high-speed stirring at 90°C for 30 min. After the reaction, cool the prepolymer product to 35°C ± 5°C and then add 190 kg of DMAC solvent and stir until fully dissolved to obtain a prepolymer solution.

[0136] S2. Add a mixed amine solution, consisting of 2.4 kg ethylenediamine, 0.15 kg propylenediamine, 0.76 kg pentanediamine, and 0.31 kg diethylamine dissolved in 46 kg DMAC, to the prepolymer solution to carry out chain extension and termination reactions, and obtain a chain-extended polyurethane polymer solution. In this step, the AN ratio is 1.04:1.

[0137] S3. Mix 3.0 kg zinc oxide, 0.86 kg titanium dioxide, 0.5 kg anti-yellowing agent, 0.3 kg antioxidant and 10 kg DMAC and put them into the grinding system. Grind for 5 hours. The solution after grinding is used as the auxiliary material solution in the spinning solution.

[0138] The excipient solution and the chain-extended polyurethane polymer solution were thoroughly mixed and matured for 5 hours.

[0139] Dissolve 4.2 kg of the above isocyanate-modified polyhexyl guanidine acid dyeing agent in 10.0 kg of DMAC to prepare a 30% modified solution.

[0140] S4. Mix the modified solution with the auxiliary solution, and allow it to fully mix and mature for 15 hours. The matured spinning solution is then spun using dry spinning to obtain spandex fiber with antibacterial and acid-dyeable composite functions.

[0141] Example 8

[0142] Preparation of isocyanate-modified polyguanidine acidic dyeing auxiliaries - isocyanate-modified polyurethane propyl biguanide dyeing auxiliaries:

[0143] 1.0 kg of polyurethane biguanide hydrochloride was dissolved in 4.0 kg of anhydrous ethanol solvent and stirred to obtain solution A with a mass concentration of 20%; 1.2 kg of 4,4-diphenylmethane diisocyanate was dissolved in 3.8 kg of DMAC solvent to obtain solution B with a mass concentration of 20%.

[0144] Slowly add solution B dropwise to solution A at a rate of 10 ml / min while mixing, keeping the stirring speed at 80 R / min and the temperature within the range of 35 ± 2℃; after adding solution B to the predetermined amount, solution C is obtained.

[0145] The aging temperature was controlled at 35℃±5℃, and the C solution was stirred for 3 hours. The aging solution was then subjected to fractional distillation to remove the organic solvent, yielding isocyanate-modified polyurethane biguanide solid.

[0146] The obtained isocyanate-modified polyurethane biguanide solid was washed with deionized water, filtered, and purified; the purified solid was dried to obtain isocyanate-modified polyurethane biguanide acidic dyeing agent.

[0147] The method for preparing antibacterial acid-dyeable composite functional spandex using the isocyanate-modified polyguanidine dyeing agent obtained by the above preparation method is as follows:

[0148] S1. Mix 100 kg of polytetramethylene ether glycol with a molecular weight of 1800 with 26 kg of 4,4-diphenylmethane diisocyanate and carry out a prepolymerization reaction under high-speed stirring at 90°C for 30 min. After the reaction, cool the prepolymer product to 35°C ± 5°C and then add 190 kg of DMAC solvent and stir until fully dissolved to obtain a prepolymer solution.

[0149] S2. Add a mixed amine solution formed by dissolving 2.5 kg ethylenediamine, 0.29 kg propylenediamine, 0.76 kg pentanediamine, and 0.31 kg diethylamine in 46 kg DMAC to the prepolymer solution to carry out chain extension and termination reactions, and obtain a chain-extended polyurethane polymer solution. In this step, the AN ratio is 1.07:1.

[0150] S3. Mix 3.0 kg zinc oxide, 0.86 kg titanium dioxide, 0.5 kg anti-yellowing agent, 0.3 kg antioxidant and 10 kg DMAC and put them into the grinding system. Grind for 5 hours. The solution after grinding is used as the auxiliary material solution in the spinning solution.

[0151] The excipient solution and the chain-extended polyurethane polymer solution were thoroughly mixed and matured for 5 hours.

[0152] Dissolve 7.1 kg of the above isocyanate-modified polyurethane biguanide acidic dyeing agent in 15.0 kg of DMAC to prepare a modified solution with a concentration of 32%.

[0153] S4. Mix the modified solution with the auxiliary solution, and allow it to fully mix and mature for 15 hours. The matured spinning solution is then spun using dry spinning to obtain spandex fiber with antibacterial and acid-dyeable composite functions.

[0154] Example 9

[0155] Preparation of isocyanate-modified polyguanidine acidic dyeing auxiliaries - isocyanate-modified polyurethane propyl biguanide dyeing auxiliaries:

[0156] 1.0 kg of polyurethane biguanide hydrochloride was dissolved in 4.0 kg of anhydrous ethanol solvent and stirred to obtain solution A with a mass concentration of 20%; 1.2 kg of 4,4-diphenylmethane diisocyanate was dissolved in 3.8 kg of DMAC solvent to obtain solution B with a mass concentration of 20%.

[0157] Slowly add solution B dropwise to solution A at a rate of 10 ml / min while mixing, keeping the stirring speed at 80 R / min and the temperature within the range of 35 ± 2℃; after adding solution B to the predetermined amount, solution C is obtained.

[0158] The aging temperature was controlled at 35℃±5℃, and the C solution was stirred for 3 hours. The aging solution was then subjected to fractional distillation to remove the organic solvent, yielding isocyanate-modified polyurethane biguanide solid.

[0159] The obtained isocyanate-modified polyurethane biguanide solid was washed with deionized water, filtered, and purified; the purified solid was dried to obtain isocyanate-modified polyurethane biguanide acidic dyeing agent.

[0160] The method for preparing antibacterial acid-dyeable composite functional spandex using the isocyanate-modified polyguanidine dyeing agent obtained by the above preparation method is as follows:

[0161] S1. Mix 100 kg of polytetramethylene ether glycol with a molecular weight of 1800 with 26 kg of 4,4-diphenylmethane diisocyanate and carry out a prepolymerization reaction under high-speed stirring at 90°C for 30 min. After the reaction, cool the prepolymer product to 35°C ± 5°C and then add 190 kg of DMAC solvent and stir until fully dissolved to obtain a prepolymer solution.

[0162] S2. Add a mixed amine solution formed by dissolving 2.5 kg ethylenediamine, 0.29 kg propylenediamine, 0.76 kg pentanediamine, and 0.31 kg diethylamine in 46 kg DMAC to the prepolymer solution to carry out chain extension and termination reactions, and obtain a chain-extended polyurethane polymer solution. In this step, the AN ratio is 1.07:1.

[0163] S3. Mix 3.0 kg zinc oxide, 0.86 kg titanium dioxide, 0.5 kg anti-yellowing agent, 0.3 kg antioxidant and 10 kg DMAC and put them into the grinding system. Grind for 5 hours. The solution after grinding is used as the auxiliary material solution in the spinning solution.

[0164] The excipient solution and the chain-extended polyurethane polymer solution were thoroughly mixed and matured for 5 hours.

[0165] Dissolve 15 kg of the above isocyanate-modified polyurethane biguanide acidic dyeing agent in 30 kg of DMAC to prepare a 30% modified solution.

[0166] S4. Mix the modified solution with the auxiliary solution, and allow it to fully mix and mature for 15 hours. The matured spinning solution is then spun using dry spinning to obtain spandex fiber with antibacterial and acid-dyeable composite functions.

[0167] Comparative Example 1

[0168] Preparation of isocyanate-modified polyguanidine acidic dyeing auxiliaries - isocyanate-modified polyurethane propyl biguanide dyeing auxiliaries:

[0169] 1.0 kg of polyurethane biguanide hydrochloride was dissolved in 4.0 kg of anhydrous ethanol solvent and stirred to obtain solution A with a mass concentration of 20%; 1.2 kg of 4,4-diphenylmethane diisocyanate was dissolved in 3.8 kg of DMAC solvent to obtain solution B with a mass concentration of 20%.

[0170] Slowly add solution B dropwise to solution A at a rate of 10 ml / min while mixing, keeping the stirring speed at 80 R / min and the temperature within the range of 35 ± 2℃; after adding solution B to the predetermined amount, solution C is obtained.

[0171] The aging temperature was controlled at 35℃±5℃, and the C solution was stirred for 3 hours. The aging solution was then subjected to fractional distillation to remove the organic solvent, yielding isocyanate-modified polyurethane biguanide solid.

[0172] The obtained isocyanate-modified polyurethane biguanide solid was washed with deionized water, filtered, and purified; the purified solid was dried to obtain isocyanate-modified polyurethane biguanide acidic dyeing agent.

[0173] The method for preparing antibacterial acid-dyeable composite functional spandex using the isocyanate-modified polyguanidine dyeing agent obtained by the above preparation method is as follows:

[0174] S1. Mix 100 kg of polytetramethylene ether glycol with a molecular weight of 1800 with 26 kg of 4,4-diphenylmethane diisocyanate and carry out a prepolymerization reaction under high-speed stirring at 90°C for 30 min. After the reaction, cool the prepolymer product to 35°C ± 5°C and then add 190 kg of DMAC solvent and stir until fully dissolved to obtain a prepolymer solution.

[0175] S2. Add a mixed amine solution, consisting of 2.4 kg ethylenediamine, 0.08 kg propylenediamine, 0.76 kg pentanediamine, and 0.31 kg diethylamine dissolved in 46 kg DMAC, to the prepolymer solution to carry out chain extension and termination reactions, and obtain a chain-extended polyurethane polymer solution. In this step, the AN ratio is 1.01:1.

[0176] S3. Mix 3.0 kg zinc oxide, 0.86 kg titanium dioxide, 0.5 kg anti-yellowing agent, 0.3 kg antioxidant and 10 kg DMAC and put them into the grinding system. Grind for 5 hours. The solution after grinding is used as the auxiliary material solution in the spinning solution.

[0177] The excipient solution and the chain-extended polyurethane polymer solution were thoroughly mixed and matured for 5 hours.

[0178] Dissolve 2.8 kg of the above isocyanate-modified polyhexyl guanidine acid dyeing agent in 5.0 kg of DMAC to prepare a modified solution with a concentration of 36%.

[0179] S4. Mix the modified solution with the auxiliary solution, and allow it to fully mix and mature for 15 hours. The matured spinning solution is then spun using dry spinning to obtain spandex fiber with antibacterial and acid-dyeable composite functions.

[0180] Comparative Example 2

[0181] Preparation of polyguanidine modified isocyanate prepolymer:

[0182] Take polyhexamethylene biguanide hydrochloride with the molecular formula (C8H17N5)n·xHCl, where n is a natural number between 12 and 16. Dissolve the polyhexamethylene biguanide hydrochloride in ethylene oxide and propylene oxide copolyether polyol to obtain a mixture. The amount of polyhexamethylene biguanide hydrochloride added is 10% of the mass of ethylene oxide and propylene oxide copolyether polyol.

[0183] The mixture obtained in the above steps was added dropwise to the polyol-modified isocyanate under heating and stirring conditions. The mass ratio of the mixture to the isocyanate was 1:5. After the addition was complete, the reaction was continued at a constant temperature of 80°C for 1 hour. After cooling, the polyguanidine-modified isocyanate prepolymer was obtained.

[0184] Composite functional spandex was prepared using the polyguanidine modified isocyanate prepolymer obtained by the above preparation method.

[0185] S1. Mix 100 kg of polytetramethylene ether glycol with a molecular weight of 1800 with 26 kg of 4,4-diphenylmethane diisocyanate and carry out a prepolymerization reaction under high-speed stirring at 90°C for 30 min. After the reaction, cool the prepolymer product to 35°C ± 5°C and then add 190 kg of DMAC solvent and stir until fully dissolved to obtain a prepolymer solution.

[0186] S2. Add a mixed amine solution, consisting of 2.4 kg ethylenediamine, 0.08 kg propylenediamine, 0.76 kg pentanediamine, and 0.31 kg diethylamine dissolved in 46 kg DMAC, to the prepolymer solution to carry out chain extension and termination reactions, and obtain a chain-extended polyurethane polymer solution. In this step, the AN ratio is 1.01:1.

[0187] S3. Mix 3.0 kg zinc oxide, 0.86 kg titanium dioxide, 0.5 kg anti-yellowing agent, 0.3 kg antioxidant and 10 kg DMAC and put them into the grinding system. Grind for 5 hours. The solution after grinding is used as the auxiliary material solution in the spinning solution.

[0188] The excipient solution and the chain-extended polyurethane polymer solution were thoroughly mixed and matured for 5 hours.

[0189] Dissolve 2.8 kg of the above-mentioned polyguanidine modified isocyanate prepolymer in 5.0 kg of DMAC to prepare a modified solution with a concentration of 36%.

[0190] S4. Mix the modified solution with the auxiliary solution, and allow it to fully mix and mature for 15 hours. The matured spinning solution is then spun using dry spinning to obtain spandex fiber with antibacterial and acid-dyeable composite functions.

[0191] Comparative Example 3

[0192] Preparation of polyguanidine modified isocyanate prepolymer:

[0193] Take polyhexamethylene biguanide hydrochloride with the molecular formula (C8H17N5)n·xHCl, where n is a natural number between 12 and 16. Dissolve the polyhexamethylene biguanide hydrochloride in ethylene oxide and propylene oxide copolyether polyol to obtain a mixture. The amount of polyhexamethylene biguanide hydrochloride added is 10% of the mass of ethylene oxide and propylene oxide copolyether polyol.

[0194] The mixture obtained in the above steps was added dropwise to the polyol-modified isocyanate under heating and stirring conditions. The mass ratio of the mixture to the isocyanate was 1:5. After the addition was complete, the reaction was continued at a constant temperature of 80°C for 1 hour. After cooling, the polyguanidine-modified isocyanate prepolymer was obtained.

[0195] Composite functional spandex was prepared using the polyguanidine modified isocyanate prepolymer obtained by the above preparation method.

[0196] S1. Mix 100 kg of polytetramethylene ether glycol with a molecular weight of 1800 with 26 kg of 4,4-diphenylmethane diisocyanate and carry out a prepolymerization reaction under high-speed stirring at 90°C for 30 min. After the reaction, cool the prepolymer product to 35°C ± 5°C and then add 190 kg of DMAC solvent and stir until fully dissolved to obtain a prepolymer solution.

[0197] S2. Add a mixed amine solution formed by dissolving 2.5 kg ethylenediamine, 0.29 kg propylenediamine, 0.76 kg pentanediamine, and 0.31 kg diethylamine in 46 kg DMAC to the prepolymer solution to carry out chain extension and termination reactions, and obtain a chain-extended polyurethane polymer solution. In this step, the AN ratio is 1.07:1.

[0198] S3. Mix 3.0 kg zinc oxide, 0.86 kg titanium dioxide, 0.5 kg anti-yellowing agent, 0.3 kg antioxidant and 10 kg DMAC and put them into the grinding system. Grind for 5 hours. The solution after grinding is used as the auxiliary material solution in the spinning solution.

[0199] The excipient solution and the chain-extended polyurethane polymer solution were thoroughly mixed and matured for 5 hours.

[0200] Dissolve 2.8 kg of the above-mentioned polyguanidine modified isocyanate prepolymer in 5.0 kg of DMAC to prepare a modified solution with a concentration of 36%.

[0201] S4. Mix the modified solution with the auxiliary solution, and allow it to fully mix and mature for 15 hours. The matured spinning solution is then spun using dry spinning to obtain spandex fiber with antibacterial and acid-dyeable composite functions.

[0202] The spandex fibers prepared in the above examples and comparative examples were dyed, and the dyeing rate was tested. The data obtained are shown in Table 1.

[0203] Table 1. Dyeing properties of spandex fibers prepared in the examples and comparative examples.

[0204]

[0205] Antibacterial tests were conducted on the spandex fibers prepared in the above examples and comparative examples. The specific antibacterial test methods were as follows: qualitative tests were performed on the fabrics using the agar diffusion method according to GB / T 20944.1-2007 "Evaluation of antibacterial properties of textiles - Part 1: Agar plate diffusion method". Quantitative antibacterial properties of the fabrics were determined according to GB / T 20944.3-2008 "Evaluation of antibacterial properties of textiles - Part 3: Shaking method". The bacterial species were Candida albicans, Staphylococcus aureus, and Escherichia coli. The test results are shown in Table 2.

[0206] Table 2. Antibacterial properties of spandex fibers prepared in the examples and comparative examples.

[0207]

[0208] Through Examples 1 to 9, it can be observed that both methods of adding auxiliary materials in step S3 can achieve uniform addition of the acidic dyeing agent. The first method involves grinding the acidic dyeing agent together with other auxiliary materials used in normal spandex production and then adding it to the polymerization solution for mixing and maturation. The second method involves first grinding the other auxiliary materials and then adding them to the chain-extended polyurethane polymer solution for mixing and maturation. Then, the isocyanate-modified polyguanidine acidic dyeing agent is dissolved in a DMAC solution and mixed and matured with the previously matured spinning solution. The two methods result in minimal differences in spandex dyeing rate and wash fastness.

[0209] Through Examples 1 to 9, it can be found that the antibacterial rate of spandex fibers can be improved by increasing the amount of isocyanate-modified polyguanidine acidic dyeing agent.

[0210] It can be seen from Example 5 and Comparative Example 1 that the AN of Example 5 is higher than that of Comparative Example 1. Example 5 ensures that the amine is in excess during the chain extension reaction, which can consume the excess active groups in the isocyanate, thereby avoiding the reaction between polyurethane and isocyanate-modified polyguanidine acid dyeing agent, thus improving the dyeing rate.

[0211] Through Example 5 and Comparative Examples 2 and 3, it can be found that Comparative Examples 2 and 3 have poor dyeing rates and poor antibacterial properties. Comparative Examples 2 and 3 used conventional methods to prepare polyguanidine-modified isocyanate prepolymers. In Comparative Examples 2 and 3, polyhexamethylene biguanide hydrochloride was dissolved in ethylene oxide-propylene oxide copolymer polyether polyol. Then, the mixture of polyhexamethylene biguanide hydrochloride and ethylene oxide-propylene oxide copolymer polyether polyol was added dropwise to the polyol-modified isocyanate under heating and stirring conditions to obtain the prepolymer. In the preparation of polyguanidine-modified isocyanate prepolymers in Comparative Examples 2 and 3, polyguanidine blocks were connected in the polyether molecular chain using isocyanate. Although this technique promotes the strength of molecular linkage, the excipient block process is uncontrollable and not homopolymerized. From the perspective of the entire molecular chain, the block may have occurred in the first half or the second half, so the mixing is uneven, which will lead to uneven dyeing, dye aggregation, and the appearance of dyeing defects.

[0212] In preparing the isocyanate-modified polyguanidine acidic dyeing auxiliary agent, this application first dissolves polyguanidine in an alcohol solvent to obtain a polyguanidine solution; then dissolves isocyanate in a strongly polar solvent to obtain an isocyanate solution; next, the isocyanate solution is slowly added dropwise to the polyguanidine solution and mixed to obtain an isocyanate-modified polyguanidine solution; the mixture is then stirred to allow it to mature; the matured isocyanate-modified polyguanidine solution is then distilled in stages to remove the organic solvent, yielding an isocyanate-modified polyguanidine solid; the obtained isocyanate-modified polyguanidine solid is washed, filtered, and purified with deionized water, and then dried to obtain the isocyanate-modified polyguanidine acidic dyeing auxiliary agent. This application achieves better dissolution at low temperatures by separately preparing the polyguanidine solution and the isocyanate solution, and then mixing them. The resulting isocyanate-modified polyguanidine has good uniformity, resulting in a high dyeing rate and good dyeing uniformity for the final spandex. Since polyguanidine antibacterial agents have poor solubility in DMAC polar solvents, chemical modification is needed to increase their solubility in DMAC. In Example 5, the isocyanate-modified polyguanidine acidic dyeing agent has good compatibility with spandex raw solution and good biocompatibility. Because this acidic dyeing agent contains a large number of amino cations, it can serve as a coloring site for acid dyes, thereby improving the dyeing performance of fibers. Therefore, this acidic dyeing agent has both antibacterial and dyeing auxiliary functions.

[0213] The difference between Comparative Example 2 and Comparative Example 3 is that Comparative Example 3 has a higher AN ratio. Therefore, the spandex product obtained by Comparative Example 3 has better dyeing rate and antibacterial properties than Comparative Example 2.

[0214] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing an antibacterial acid-dyeable composite functional spandex, characterized in that, Comprise: S1, polytetramethylene ether glycol and 4,4 diphenyl methane diisocyanate are mixed for prepolymerization, after the prepolymerization is finished, the prepolymer product is cooled, then DMAC solvent is added and stirred until fully dissolved, to obtain a prepolymer solution; S2, a mixed amine solution dissolved in DMAC is added to the obtained prepolymer solution for chain extension and termination reaction, the molar ratio AN of amine groups in the mixed amine to the remaining -NCO in the prepolymer is controlled to be 1.04~1.07, to obtain a chain-extended polyurethane polymer solution; S3, auxiliary materials and isocyanate-modified polyguanidine acid dyeing assistants are added to the chain-extended polyurethane polymer solution to obtain a spinning dope after stirring and maturation; S4, the maturation of the spinning dope is carried out by dry spinning to obtain spandex with antibacterial and acid-dyeable composite functions; The isocyanate-modified polyguanidine acid dyeing assistant is obtained by the following method: Polyguanidine is dissolved in an alcohol solvent to obtain solution A; isocyanate is dissolved in a strong polar solvent to obtain solution B; solution B is slowly added to solution A, and after solution B is added to a certain amount, solution C is obtained; Continue to stir solution C for maturation, the maturation temperature is 30~40 DEG C, the matured solution C is distilled in sections to remove organic solvents, to obtain isocyanate-modified polyguanidine solid; the obtained isocyanate-modified polyguanidine solid is washed with deionized water, filtered and purified, and then dried after purification to obtain isocyanate-modified polyguanidine acid dyeing assistant.

2. The production method according to claim 1, wherein The polyguanidine is a mixture of one or more of polyhexamethylene biguanide or polyhexamethylene biguanide hydrochloride, polyaminopropyl biguanide or polyaminopropyl biguanide hydrochloride.

3. The production method according to claim 1, wherein The alcohol solvent is a mixture of one or more of methanol, ethanol, propanol and butanol.

4. The production method according to claim 1, wherein The isocyanate is one of toluene diisocyanate, 4,4 diphenyl methane diisocyanate and hexamethylene diisocyanate; the strong polar solvent is a mixture of one or more of DMAC, DMSO and DMF.

5. The production method according to claim 1, wherein In step S3, the auxiliary materials and the isocyanate-modified polyguanidine acid dyeing assistant are added in the following manner: The isocyanate-modified polyguanidine acid dyeing assistant, auxiliary materials and DMAC are mixed, ground and grinded in a mass ratio of 0~0.2:0.04~0.58:1, and the solution after grinding is used as the auxiliary material solution in the spinning dope, wherein the amount of isocyanate-modified polyguanidine acid dyeing assistant is not 0; The auxiliary material solution and the chain-extended polyurethane polymer solution are mixed in a mass ratio of 0.01~0.4:1, and maturation is carried out.

6. The production method according to claim 1, wherein In step S3, the auxiliary materials and the isocyanate-modified polyguanidine acid dyeing assistant are added in the following manner: The auxiliary materials and DMAC are mixed and ground in a mass ratio of 0.08~0.96:1, and the solution after grinding is used as the auxiliary material solution in the spinning dope; The isocyanate-modified polyguanidine acid dyeing assistant is dissolved in DMAC to prepare a solution with a concentration of 10.00%~40.00%, which is used as a modified solution; First, the auxiliary material solution and the chain-extended polyurethane polymer solution are mixed and matured, the modified solution is added after uniform mixing, and the mixture is mixed and matured again; The mass ratio of the auxiliary material solution, the modified solution and the polyurethane polymer solution is 0.03-0.15:0.01-0.13:

3.

7. The production method according to claim 1, wherein The chain extender of the chain extension reaction is ethylenediamine, propylenediamine, pentanediamine or a mixture thereof, and the terminating agent for terminating the reaction is diethylamine, wherein the molar ratio of the chain extender:DMAC is 0.04-0.17:1.

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