Isoparaffin medium cationic dye dyeing method of aramid fiber
By adding trace amounts of water and dyeing carrier to the isoalkane medium, the problems of insufficient dye dispersion and swelling in aramid fiber dyeing were solved, achieving efficient and environmentally friendly aramid fiber dyeing, improving the dyeing rate and reducing energy consumption and wastewater discharge.
Patent Information
- Application Number
- CN202511200496.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-26
- Publication Date
- 2025-11-14
AI Technical Summary
Aramid fibers are difficult to dye efficiently in isoalkane media, with problems such as poor dye dispersion and insufficient fiber swelling, resulting in low dye uptake and failure to meet industrial application requirements.
By introducing trace amounts of water and specific dyeing carriers, such as N,N-dimethylacetamide and fatty alcohol polyoxyethylene ether, into the isoalkane medium, a polar microenvironment is formed, which promotes the diffusion and fixation of dyes inside the fiber, and a dyeing process under mild conditions is adopted.
It significantly improves the dye uptake rate and dyeing uniformity, reduces energy consumption and wastewater discharge, meets environmental protection requirements, and satisfies the usage standards for high-end textiles.
Smart Images
Figure CN120945690A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of fiber dyeing technology, and in particular to a method for dyeing aramid fibers with cationic dyes in an isoparaffinic medium. Background Technology
[0002] Aramid, short for poly(p-phenylene terephthalamide), is a high-tech synthetic fiber with excellent mechanical properties, thermal stability, flame retardancy, and electrical insulation. Due to its highly regular molecular chain, high crystallinity, and strong surface chemical inertness, aramid is a typical difficult-to-dye fiber.
[0003] Traditional aramid dyeing methods typically employ disperse or cationic dyes in an aqueous system, often requiring high temperature and pressure (above 130°C), prolonged dyeing times, or the introduction of large amounts of carriers (such as benzophenone or methyl salicylate) to enhance the affinity between the dye and the fiber. However, these methods generally suffer from high energy consumption, low dye utilization, poor dyeing uniformity, and the generation of large amounts of difficult-to-treat colored wastewater, which contradicts increasingly stringent environmental regulations and the "dual carbon" goal.
[0004] To address the drawbacks of aqueous dyeing, anhydrous / low-water dyeing technologies such as organic solvent dyeing and supercritical carbon dioxide dyeing have become research hotspots. Among these, non-polar solvents, represented by isoalkanes, have shown application potential in dyeing hydrophobic fibers such as polyester due to their advantages of being non-toxic, chemically stable, and recyclable. However, directly applying this system to the cationic dyeing of aramid fibers faces two major technical bottlenecks: first, cationic dyes exhibit extremely poor dispersibility in non-polar isoalkanes, easily leading to flocculation and sedimentation; second, inert aramid fibers are difficult to swell in non-polar media, preventing effective dye penetration into the fiber interior. Therefore, simply mixing cationic dyes with isoalkanes for dyeing aramid results in extremely low dye uptake rates, hindering industrial application. Summary of the Invention
[0005] The purpose of this invention is to provide a method for dyeing aramid fibers with cationic dyes in an isoalkane medium. This method overcomes the technical problems of high energy consumption, heavy pollution, and low dyeing rate in existing aramid dyeing methods, and can achieve efficient, uniform, and environmentally friendly dyeing under mild conditions.
[0006] The technical solution adopted by this invention to solve its technical problem is:
[0007] A method for dyeing aramid fibers with cationic dyes in an isoalkane medium, the method comprising the following steps: S1, preparing a dye bath composed of a cationic dye, isoalkane as a dyeing medium, and a polar auxiliary agent as a dyeing auxiliary; wherein the polar auxiliary agent is water and / or a dyeing carrier, the dyeing carrier being selected from one or more of ethanol, N,N-dimethylformamide, N,N-dimethylacetamide, methyl cinnamate, fatty alcohol polyoxyethylene ether, isooctyl benzoate, acetophenone, benzyl alcohol, and ethylene glycol phenyl ether, wherein the amount of dyeing carrier added is 1-10% of the total mass of the isoalkane, for promoting the swelling of the aramid fibers and the diffusion of the dye; S2, adding the aramid fibers to the dye bath at a bath ratio of 1:(10-35), and performing dyeing treatment involving heating, holding, and cooling; S3, performing post-treatment on the dyed aramid fibers to obtain dyed aramid fibers.
[0008] The inventors unexpectedly discovered during their research that introducing trace amounts of water and a specific dyeing carrier into the isoalkane-cationic dye system can produce an unexpected synergistic effect, thus perfectly solving the aforementioned technical problem.
[0009] Preferably, step S1 specifically includes: mixing the cationic dye with the isoalkane medium at a mass ratio of 1:(5-15) and grinding for 2-6 hours to prepare a dye mother liquor; mixing the dye mother liquor, isoalkane and polar auxiliaries to obtain the dye solution; the amount of dye mother liquor added is based on 2%-6% (owf) of dye.
[0010] Preferably, the mass ratio of the cationic dye to the isoalkane medium in S1 is 1:10, and the grinding process is carried out at a temperature of 25-35°C, using zirconium beads as the grinding medium, and the grinding time is 3-5 hours, in order to obtain dye microparticles with uniform particle size and good dispersibility.
[0011] The dyeing bath ratio described in S2 is 1:(10-35). This dyeing bath ratio reduces the use of isoparaffinic media.
[0012] Preferably, step S1 specifically includes: the staining treatment in S2 includes:
[0013] Temperature increase: Inoculate at room temperature, increase the temperature to 70℃ at a rate of 1-3℃ / min, and then continue to increase the temperature to 110-140℃ (preferably to 110-120℃) at a rate of 1-3℃ / min.
[0014] Incubation: Incubate at the highest staining temperature for 35-75 minutes;
[0015] Cooling: After the heat preservation time is over, cool down to 50-70℃ at a rate of 1-3℃ / min.
[0016] Preferably, the isoalkanes are one or more of isododecane, isotridecane, isotetradecane, or isohexadecane; these isoalkanes have moderate boiling points and good volatility stability, and can provide a relatively ideal solvent environment during the dyeing process, which helps to improve the dispersibility of dyes and the swelling of fibers, thereby significantly improving the dyeing effect and the dyeing rate of fibers.
[0017] Preferably, the cationic dye is selected from one or more of cationic Brilliant Red X-5GN, cationic Sapphire Blue X-GRL, and cationic Yellow X-10GFF. It exhibits good color fastness and high affinity, making it suitable for high-temperature dyeing systems for aramid fibers.
[0018] Preferably, the aramid fiber is a meta-aramid staple fiber, filament, or nonwoven fabric substrate.
[0019] Preferably, the isomeric alkane has 12-16 carbon atoms and is an alkane without any special groups other than methyl and methylene groups.
[0020] Preferably, the polar auxiliary agent is water and a dyeing carrier, which is composed of N,N-dimethylacetamide and fatty alcohol polyoxyethylene ether. The amount of N,N-dimethylacetamide is 10-50% relative to the weight of the aramid fiber, and the amount of fatty alcohol polyoxyethylene ether is 5-25% relative to the weight of the aramid fiber.
[0021] Preferably, the amount of N,N-dimethylacetamide is 40% relative to the weight of the aramid fiber, and the amount of fatty alcohol polyoxyethylene ether is 15% relative to the weight of the aramid fiber.
[0022] Preferably, the amount of water used is 10-150% relative to the weight of the aramid fiber. Most preferably, the amount of water used is 50% relative to the weight of the aramid fiber.
[0023] Preferably, the post-treatment in step S3 includes water washing and soap washing to remove floating color, wherein the soap washing solution in the soap washing treatment contains anhydrous sodium carbonate and soap flakes.
[0024] Preferably, the soaping method is as follows: first, remove the dyed fibers and rinse them with cold water for 10-15 minutes; then, prepare a soaping solution with a mass concentration of 1-3 g / L, at a temperature of 70-90℃, for 10-20 minutes. The soaping solution uses a nonionic or anionic surfactant.
[0025] As a preferred option, the soap solution is formulated with 2 g / L anhydrous sodium carbonate, 2 g / L soap flakes, and a liquor ratio of 1:50.
[0026] The beneficial effects of this invention are:
[0027] 1. This invention introduces water and a specific dyeing carrier into the isoparaffin dyeing system, resulting in a synergistic effect. Trace amounts of water may create a polar microenvironment around the dye particles, while the carrier promotes fiber swelling. Together, they significantly enhance the diffusion and fixation of the dye into the fiber. A comparison of Examples 1, 2, and 5 shows that using both water and the carrier simultaneously results in a significantly higher dyeing depth (K / S value 15.15) than using water alone (K / S value 4.66) or the carrier alone (K / S value 3.9), demonstrating the synergistic effect and high dyeing rate of this composite auxiliary system.
[0028] 2. Due to the introduction of the composite auxiliary agent system, the present invention can obtain excellent dyeing effect at a relatively low temperature of 120°C, which significantly reduces energy consumption compared with the high temperature of more than 130°C for traditional aqueous dyeing.
[0029] 3. This invention uses recyclable isoalkanes as the main medium, and the dyeing process uses very little water, thus solving the problem of large-scale generation and discharge of dyeing and printing wastewater at the source, which is in line with the industrial development direction of green manufacturing.
[0030] Furthermore, the dyed aramid fibers obtained by the method of this invention have excellent color fastness to soap washing, meeting the requirements for use in high-end textiles. Attached Figure Description
[0031] Figure 1 This is the sample stained in Example 1;
[0032] Figure 2 This is the sample after staining in Example 2;
[0033] Figure 3 This is the sample after staining in Example 5. Detailed Implementation
[0034] The technical solution of the present invention will be further described in detail below through specific embodiments. It should be understood that the implementation of the present invention is not limited to the following embodiments, and any modifications and / or alterations made to the present invention will fall within the protection scope of the present invention.
[0035] In this invention, unless otherwise specified, all parts and percentages are by weight, and the equipment and raw materials used are commercially available or commonly used in the art. Unless otherwise specified, the methods in the following embodiments are conventional methods in the art.
[0036] Unless otherwise specified, the reagents used in the following examples can be purchased from a regular biochemical reagent store.
[0037] The dyeing process in the following embodiments uses a closed reaction vessel for heating and dyeing to maintain the stability of the dye solution system and prevent the volatilization loss of isoalkane media. A very small amount of water is added during the dyeing process, significantly reducing wastewater discharge and post-treatment burden compared to traditional aqueous dyeing.
[0038] Example 1:
[0039] A method for dyeing aramid fibers with cationic brilliant red X-5GN in an isoparaffin medium, the specific steps of which are as follows:
[0040] (1) Preparation of dye mother liquor: Cationic Brilliant Red X-5GN and isoalkane medium were mixed at a mass ratio of 1:10, zirconium beads were added and the mixture was ground for 5 h to obtain dye mother liquor;
[0041] The isoalkane medium is isohexadecane, and its physical parameters are shown in Table 1.
[0042] Table 1. Parameters of isohexadecane used in Example 1
[0043]
[0044] (2) Preparation of dyeing solution: 1 g of aramid fiber and 20 g of isoparaffin medium were added at a bath ratio of 1:20, followed by the dye mother liquor obtained in step (1) (the amount added was based on 2% (owf) of dye), 0.5 g of water and 0.45 g of dyeing carrier; the dyeing carrier was composed of 0.4 g of N,N-dimethylacetamide (accounting for 40% of the weight of aramid fiber) and 0.15 g of fatty alcohol polyoxyethylene ether (accounting for 15% of the weight of aramid fiber).
[0045] (3) Staining: stain at room temperature, raise the temperature to 70℃ at 1.5℃ / min, hold for 20min, continue to raise the temperature to 120℃ at 1℃ / min, and hold for 45min; then lower the temperature to 70℃ at 2.5℃ / min.
[0046] (4) Soap washing: First, take out the dyed fiber and rinse it with cold water for 10 min. Prepare a soap washing solution containing 2 g / L of anhydrous sodium carbonate, 2 g / L of soap flakes, and a bath ratio of 1:50. Add the washed fiber and soap wash it at 70 ℃ for 15-20 min. Finally, wash and dry the fiber to obtain the dyed fiber.
[0047] The staining formula and conditions in the staining method are as follows:
[0048] Cationic dye (Cationic Brilliant Red X-5GN): 2% (owf)
[0049] Aramid fiber: 1 g
[0050] Bath ratio: 1:20
[0051] Results of stained samples are shown below Figure 1 And Table 2.
[0052] Example 2: A method for dyeing aramid fibers with cationic bright red X-5GN in isoparaffin medium. The specific steps of this method are the same as those in Example 1, except that the mass of water added in step (2) of this example is 0 g.
[0053] Results of stained samples are shown below Figure 2 And Table 2.
[0054] Example 3: A method for dyeing aramid fibers with cationic bright red X-5GN in isoparaffin medium. The specific steps of this method are the same as those in Example 1, except that the mass of water added in step (2) of this example is 1 g.
[0055] The results of the stained samples are shown in Table 2.
[0056] Example 4: A method for dyeing aramid fibers with cationic bright red X-5GN in isoparaffin medium. The specific steps of this method are the same as those in Example 1, except that the mass of water added in step (2) of this example is 1.5 g.
[0057] The results after staining are shown in Table 2.
[0058] Example 5: A method for dyeing aramid fibers with cationic bright red X-5GN in isoalkane medium. The specific steps of this method are the same as those in Example 1, except that the mass of the dyeing carrier added in step (2) of this example is 0 g.
[0059] See the results after staining Figure 3 And Table 2.
[0060] Example 6: A method for dyeing aramid fibers with cationic bright red X-5GN in isoalkane medium. The specific steps of this method are the same as those in Example 1, except that the amount of dye added in step (2) of this example is 4% (owf).
[0061] The results after staining are shown in Table 2.
[0062] Example 7: A method for dyeing aramid fibers with cationic bright red X-5GN using isoparaffin media. The specific steps of this method are the same as those in Example 1, except that the alkane added in step (2) of this example is replaced with the same mass of water.
[0063] The results after staining are shown in Table 2.
[0064] Example 8: A method for dyeing aramid fibers with cationic bright red X-5GN in isoalkane medium. The specific steps of this method are the same as those in Example 1, except that the dye added in step (2) of this example is not mechanically ball-milled in step (1).
[0065] The results after staining are shown in Table 2.
[0066] Example 9: A method for dyeing aramid fibers with cationic bright red X-5GN in isoparaffin medium. The specific steps of this method are the same as those in Example 1, except that the heat preservation temperature for dyeing in step (3) of this example is 130℃.
[0067] The results after staining are shown in Table 2.
[0068] Table 2. Dyeing effects of aramid fibers
[0069]
[0070] Table 3. Wash fastness of dyed fibers
[0071]
[0072] in conclusion
[0073] The results above show that, under the same dyeing process conditions, introducing a small amount of water into the isoalkane medium can significantly improve the dye uptake rate of aramid fibers. Simultaneously, the introduction of the dyeing carrier effectively improves the dye diffusion and fiber swelling behavior in the medium, enabling efficient dyeing at a lower temperature (approximately 120℃), which is superior to the traditional process requiring dyeing at temperatures above 130℃. This process not only improves dyeing efficiency but also significantly reduces energy consumption and wastewater discharge, demonstrating excellent energy-saving and environmental protection effects.
Claims
1. A method for dyeing aramid fibers with cationic dyes in an isoparaffinic medium, characterized in that, The method includes the following steps: S1, preparing a dye solution composed of a cationic dye, an isoparaffin as a dyeing medium, and a polar auxiliary agent as a dyeing auxiliary agent; The polar auxiliary agent is water and / or a dyeing carrier, wherein the dyeing carrier is selected from one or more of ethanol, N,N-dimethylformamide, N,N-dimethylacetamide, methyl cinnamate, fatty alcohol polyoxyethylene ether, isooctyl benzoate, acetophenone, benzyl alcohol, and ethylene glycol phenyl ether, and the amount of the dyeing carrier added is 1-10% of the total mass of the isoparaffins; S2, aramid fibers are added to the dyeing liquor at a liquor ratio of 1:(10-35) and dyeing treatment is carried out by heating, holding and cooling; S3, the dyed aramid fibers are post-treated to obtain dyed aramid fibers.
2. The method according to claim 1, characterized in that... Step S1 specifically includes: The cationic dye and isoparaffin medium are mixed at a mass ratio of 1:(5-15) and ground for 2-6 hours to prepare a dye mother liquor. The dye mother liquor, isoparaffin, and polar auxiliaries are mixed to obtain the dye liquor; the amount of dye mother liquor added is based on 2%-6% (owf) of dye.
3. The method according to claim 1, characterized in that... Step S1 specifically includes: The staining process described in S2 includes: Temperature increase: Inoculate at room temperature, increase the temperature to 70℃ at a rate of 1-3℃ / min, and then continue to increase the temperature to 110-140℃ at a rate of 1-3℃ / min. Incubation: Incubate at the highest staining temperature for 35-75 minutes; Cooling: After the heat preservation time is over, cool down to 50-70℃ at a rate of 1-3℃ / min.
4. The method according to claim 1, characterized in that, The isoalkane is one or more of isododecane, isotridecane, isotetradecane, or isohexadecane; the cationic dye is selected from one or more of cationic Brilliant Red X-5GN, cationic Sapphire Blue X-GRL, and cationic Yellow X-10GFF.
5. The method according to claim 1, characterized in that, The polar auxiliaries are water and a dyeing carrier, which is composed of N,N-dimethylacetamide and fatty alcohol polyoxyethylene ether. The amount of N,N-dimethylacetamide is 10-50% relative to the weight of the aramid fiber, and the amount of fatty alcohol polyoxyethylene ether is 5-25% relative to the weight of the aramid fiber.
6. The method according to claim 5, characterized in that, The amount of N,N-dimethylacetamide is 40% relative to the weight of the aramid fiber, and the amount of fatty alcohol polyoxyethylene ether is 15% relative to the weight of the aramid fiber.
7. The method according to claim 5, characterized in that, The amount of water used is 10-150% relative to the weight of the aramid fiber.
8. The method according to claim 5, characterized in that, The amount of water used is 50% relative to the weight of the aramid fiber.
9. The method according to claim 1, characterized in that, The post-treatment described in step S3 includes water washing and soap washing to remove floating color. The soap washing solution in the soap washing process contains anhydrous sodium carbonate and soap flakes.