Method for dyeing polyimide yarn with two dyes

Abstract

The present invention belongs to the technical field of textile printing and dyeing, and particularly relates to a method for double-dyeing polyimide yarns. It includes: (1) injecting a disperse dye solution into a coloring device, and the polyimide yarns adsorb the disperse dye solution during the winding process, and after extrusion and smearing treatment, they are wound into loose-wound cheese; (2) subjecting the loose-wound cheese in step (1) to steam fixation treatment, then performing reduction cleaning and water washing, dehydrating and drying to obtain polyimide pre-dyed yarns; (3) injecting a cationic dye solution into the coloring device, and the polyimide pre-dyed yarns adsorb the cationic dye solution during the winding process, and after extrusion and smearing treatment, they are wound into loose-wound cheese; (4) subjecting the loose-wound cheese in step (3) to steam fixation treatment, then performing soaping and water washing, dehydrating and drying to obtain double-dyeing polyimide yarns; adopting a two-step dyeing process, first performing preliminary dyeing with disperse dyes, and then deepening the dyeing with cationic dyes, and the obtained polyimide dyed yarns have a high dyeing depth and good color fastness.

Description

Technical Field

[0001] The present invention belongs to the technical field of textile printing and dyeing, and particularly relates to a method for dyeing polyimide yarns with double dyes. Background Art

[0002] Polyimide fiber (PI) refers to a fiber containing aromatic imide in its molecular chain, which can generally be prepared by polycondensation reaction of acid anhydride and aromatic diisocyanate in solvents such as dimethylformamide, followed by spinning. Polyimide fiber has a variety of excellent properties, such as good spinnability, flame retardancy, excellent heat insulation performance, non-melting and dripping characteristics, self-extinguishing ability when removed from fire, chemical corrosion resistance, radiation resistance, high strength and high modulus, etc. The conjugated structure of its molecular chain makes it have better high-temperature resistance than aromatic polyamide fiber. Therefore, polyimide fiber can be used to make textiles required for various special occasions, such as military protective clothing, medical and hygienic protective clothing, special clothing for preventing biochemical weapons, racing car flame-retardant clothing, aerospace clothing, and high-efficiency smoke protection masks. Polyimide fabric also has excellent dimensional stability and safety, and a long service life. However, due to the highly conjugated structure of the molecular main chain of polyimide fiber, it has a high molecular orientation degree, a high glass transition temperature, and the fiber itself presents a golden yellow color. These factors make polyimide fiber face problems such as low dye uptake rate and poor deep dyeing property in dyeing and finishing processes, thus restricting its development and application in the textile and clothing field.

[0003] Currently, the main dyeing methods for polyimide fiber include carrier dyeing method, fiber pretreatment dyeing method, solvent dyeing method, etc. Chinese Patent CN107287933A discloses a dyeing method for polyimide fiber or polyimide fabric. This method has a relatively high dye uptake rate and good fastness, but the dyeing carrier used has certain environmental hazards. Chinese Patent CN113445331A discloses a dyeing method for improving the dyeing performance of polyimide fiber, which pretreats the fiber with an alkaline pretreatment solution. This method enhances the dyeing performance of the fiber, but to a certain extent affects the mechanical properties of the fiber. Chinese Patent CN106087379A discloses an anhydrous dyeing method for polyimide fabric, which uses disperse dyes to dye polyimide fabric in supercritical carbon dioxide. The dyed fabric has a high color depth and good color fastness, but this method has a large process difficulty, and after dyeing, the disperse dyes and carbon dioxide need to be recovered separately, making it difficult to achieve mass production. Summary of the Invention

[0004] Aiming at the deficiencies of the prior art, the purpose of the present invention is to provide a method for double-dyeing polyimide yarns. A two-step dyeing process is adopted. First, preliminary dyeing is carried out with disperse dyes, and then cationic dyes are used to deepen the dyeing. The obtained polyimide dyed yarns have high dyeing depth and good color fastness. The dyeing process is carried out at room temperature without pre-treatment of the yarns, effectively reducing the strength loss of the yarns, lowering energy consumption, being green and environmentally friendly, and being easy for industrial production.

[0005] The technical solution adopted by the present invention is as follows:

[0006] The method for double-dyeing polyimide yarns includes the following steps:

[0007] (1) Preliminary dyeing: Inject the disperse dye solution into the material tank of the coloring device. The polyimide yarns are saturated with the disperse dye solution during the winding process, and then undergo extrusion and coating treatment, and finally are wound into loose-wound cheese.

[0008] (2) Preliminary fixation and post-treatment: Place the loose-wound cheese obtained in step (1) in a steamer for steam fixation treatment. After the steam fixation is completed, put it into a cheese dyeing machine for reduction cleaning and water washing. After the water washing is completed, dehydrate and dry it to obtain polyimide pre-dyed yarns.

[0009] (3) Deepening dyeing: Inject the cationic dye solution into the material tank of the coloring device. The polyimide pre-dyed yarns are saturated with the cationic dye solution again during the winding process, and then undergo extrusion and coating treatment, and are wound into loose-wound cheese.

[0010] (4) Deepening fixation and post-treatment: Put the loose-wound cheese obtained in step (3) into a steamer for steam fixation treatment. After the steam fixation is completed, send it into a cheese dyeing machine for soaping and water washing. After the water washing is completed, dehydrate and dry it to obtain double-dyeing polyimide yarns.

[0011] The disperse dye solution includes disperse dyes, dispersants and penetrants. Among them, the concentration of the disperse dyes is 1-7 wt.%, the concentration of the dispersants is 0.1-0.2 wt.%, and the concentration of the penetrants is 0.5-1 wt.%.

[0012] The cationic dye solution includes cationic dyes and penetrants. Among them, the concentration of the cationic dyes is 1-10 wt.%, and the concentration of the penetrants is 0.5-1 wt.%.

[0013] The pH value of the disperse dye solution is 4-5, and its pH value is adjusted with a neutralizing acid. The neutralizing acid is an aqueous dispersion of an organic acid and a dispersant.

[0014] The pH value of the cationic dye solution is 4-5, and its pH value is adjusted with glacial acetic acid.

[0015] The coloring device described above is the single yarn on-line coating device in Chinese Patent CN116716734A. The dyeing solution is added into the material tank of the single yarn on-line coating device, and the polyimide yarn is transferred and adsorbed with the dyeing solution through the liquid feeding wheel by the operation of the device, and then wound into a loose bobbin after being coated by the extrusion device.

[0016] In the step (1) described above, the winding speed of the yarn is 400 - 800 m / min, and the liquid carrying rate of the loose bobbin is 20 - 30%.

[0017] In the step (2) described above, the temperature for steam fixation is 130 - 140 °C, and the time is 30 - 50 min.

[0018] In the step (2) described above, non-ionic reducing cleaning agent is used for reduction cleaning. The non-ionic reducing cleaning agent is neutral or acidic. The dosage of the reducing cleaning agent is 1 - 2 g / L, the temperature for reduction cleaning is 80 - 90 °C, and the time is 20 - 30 min.

[0019] In the step (3) described above, the winding speed of the yarn is 400 - 800 m / min, and the liquid carrying rate of the loose bobbin is 30 - 40%.

[0020] In the step (4) described above, the temperature for steam fixation is 130 - 140 °C, and the time is 30 - 50 min.

[0021] In the step (4) described above, anionic soap detergent is used for soaping. The dosage of the soap detergent is 1 - 3 g / L, the temperature for soaping is 80 - 105 °C, and the time is 20 - 30 min.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0023] (1) For the method for double-dyeing polyimide yarn described in the present invention, there is no need for yarn pretreatment, and no carrier is used during the dyeing process, making the production process more environmentally friendly.

[0024] (2) Through the two-step dyeing method in the present invention, preliminary dyeing is first carried out with disperse dyes, and then cationic dyes are used for depth enhancement dyeing. The obtained polyimide yarn has a high dyeing depth and good dyeing fastness.

[0025] (3) The dyeing process of the present invention is carried out under normal temperature conditions, and the fixation process uses steam under non-water bath conditions, with small loss of yarn strength, low energy consumption, low requirements for production equipment, and high production efficiency, being suitable for industrial production. Specific Embodiments

[0026] The following further illustrates the present invention in conjunction with embodiments, but it does not limit the implementation of the present invention.

[0027] Unless otherwise specified, the raw materials used in the examples and comparative examples are all conventional commercially available raw materials, and the process methods used in the examples and comparative examples are all conventional methods in the art.

[0028] Descriptions of some of the raw materials used in the examples and comparative examples are as follows:

[0029] Disperse Blue BE-RPD, purchased from Sumitomo Chemical (Shanghai) Co., Ltd.;

[0030] Disperse Black BKSWF, purchased from Yorkshire (China) Trading Co., Ltd.;

[0031] Disperse Red RS-WF, purchased from Archroma Chemicals (China) Co., Ltd.;

[0032] Cationic Blue BFGRL, purchased from DyStar (Shanghai) Trading Co., Ltd.;

[0033] Cationic Black BKFDL, purchased from DyStar (Shanghai) Trading Co., Ltd.;

[0034] Cationic Red RFBL, purchased from DyStar (Shanghai) Trading Co., Ltd.;

[0035] Dispersant RDT-35, purchased from Shanghai Xintian Economic and Trade Co., Ltd.;

[0036] Penetrant WA-M, purchased from Zibo Lurui Fine Chemical Co., Ltd.;

[0037] Neutralizing acid AB acid, purchased from Toner Trading (Shanghai) Co., Ltd.;

[0038] Reductive cleaning agent RC-200, purchased from Dorn Biotechnology Co., Ltd.;

[0039] Soaping agent PERMULSIN-553, purchased from Busse Chemical (Ningbo) Co., Ltd.

[0040] Example 1

[0041] The method for double-dyeing polyimide yarns includes the following steps:

[0042] (1) Preliminary dyeing: Inject the disperse dye solution into the trough of the coloring device. The polyimide yarns are saturated with the disperse dye solution during the winding process. The winding speed is 800 m / min, and then through extrusion and smearing treatment, and finally wound into a loose bobbin. The liquor ratio of the loose bobbin is 20%;

[0043] (2) Preliminary Fixation and Post-treatment: Place the open-width cheese yarn obtained in step (1) in a steamer and perform steam fixation treatment using saturated steam. The temperature for steam fixation is 130 °C and the time is 30 min. After the steam fixation is completed, put it into a cheese yarn dyeing machine for reduction cleaning and water washing. During the reduction cleaning process, use reduction cleaning agent RC-200, and the dosage of the reduction cleaning agent is 1 g / L. The temperature for reduction cleaning is 80 °C and the time is 20 min. After the water washing is completed, perform dehydration and drying to obtain the polyimide pre-dyed yarn;

[0044] (3) Deepening Dyeing: Inject the cationic dye solution into the material tank of the coloring device. The polyimide pre-dyed yarn is saturated with the cationic dye solution again during the winding process. The winding speed is 800 m / min, and then after extrusion and coating treatment, it is wound into an open-width cheese yarn. The liquor ratio of the open-width cheese yarn is 30%;

[0045] (4) Deepening Fixation and Post-treatment: Place the open-width cheese yarn obtained in step (3) in a steamer and perform steam fixation treatment using saturated steam. The temperature for steam fixation is 130 °C and the time is 30 min. After the steam fixation is completed, send it into a cheese yarn dyeing machine for soaping and water washing. During the soaping process, use soaping agent PERMULSIN-553, and the dosage of the soaping agent is 1 g / L. The temperature for soaping is 80 °C and the time is 20 min. After the water washing is completed, perform dehydration and drying to obtain the double-dyeing polyimide yarn;

[0046] The dispersion dye solution includes Disperse Blue BE-RPD, dispersant RDT-35, and penetrant WA-M. Among them, the concentration of Disperse Blue BE-RPD is 1 wt.%, the concentration of dispersant RDT-35 is 0.1 wt.%, and the concentration of penetrant WA-M is 0.5 wt.%. Use neutralizing acid AB acid to adjust the pH value of the dispersion dye solution to 5;

[0047] The cationic dye solution includes Cationic Blue BFGRL and penetrant WA-M. Among them, the concentration of Cationic Blue BFGRL is 1 wt.%, and the concentration of penetrant WA-M is 0.5 wt.%. Use glacial acetic acid to adjust the pH value of the cationic dye solution to 5.

[0048] Example 2

[0049] The method for double-dyeing polyimide yarn includes the following steps:

[0050] (1) Preliminary Dyeing: Inject the dispersion dye solution into the material tank of the coloring device. The polyimide yarn is saturated with the dispersion dye solution during the winding process. The winding speed is 600 m / min, and then after extrusion and coating treatment, it is finally wound into an open-width cheese yarn. The liquor ratio of the open-width cheese yarn is 25%;

[0051] (2) Preliminary fixation and post-treatment: Place the open-width cheese yarn obtained in step (1) in a steamer and perform steam fixation treatment using saturated steam. The temperature for steam fixation is 140 °C and the time is 35 min. After the steam fixation is completed, put it into a cheese yarn dyeing machine for reduction cleaning and water washing. During the reduction cleaning process, reduction cleaning agent RC-200 is used, and the dosage of the reduction cleaning agent is 2 g / L. The temperature for reduction cleaning is 90 °C and the time is 30 min. After the water washing is completed, perform dehydration and drying to obtain the polyimide pre-dyed yarn;

[0052] (3) Deepening dyeing: Inject the cationic dye solution into the material tank of the coloring device. The polyimide pre-dyed yarn is saturated with the cationic dye solution again during the winding process. The winding speed is 600 m / min, and then it undergoes extrusion and coating treatment and is wound into an open-width cheese yarn. The liquor ratio of the open-width cheese yarn is 35%;

[0053] (4) Deepening fixation and post-treatment: Place the open-width cheese yarn obtained in step (3) in a steamer and perform steam fixation treatment using saturated steam. The temperature for steam fixation is 135 °C and the time is 35 min. After the steam fixation is completed, send it into a cheese yarn dyeing machine for soaping and water washing. During the soaping process, soaping agent PERMULSIN-553 is used, and the dosage of the soaping agent is 2 g / L. The temperature for soaping is 90 °C and the time is 20 min. After the water washing is completed, perform dehydration and drying to obtain the double-dyeing polyimide yarn;

[0054] The dispersion dye solution includes Disperse Black BKSWF, dispersant RDT-35, and penetrant WA-M. Among them, the concentration of Disperse Black BKSWF is 7 wt.%, the concentration of dispersant RDT-35 is 0.2 wt.%, and the concentration of penetrant WA-M is 1 wt.%. The pH value of the dispersion dye solution is adjusted to 4 using neutralizing acid AB acid;

[0055] The cationic dye solution includes Cationic Black BKFDL and penetrant WA-M. Among them, the concentration of Cationic Black BKFDL is 5 wt.%, the concentration of penetrant WA-M is 0.5 wt.%. The pH value of the cationic dye solution is adjusted to 4 using glacial acetic acid.

[0056] Example 3

[0057] The method for double-dyeing polyimide yarn includes the following steps:

[0058] (1) Preliminary dyeing: Inject the dispersion dye solution into the material tank of the coloring device. The polyimide yarn is saturated with the dispersion dye solution during the winding process. The winding speed is 700 m / min, and then it undergoes extrusion and coating treatment and is finally wound into an open-width cheese yarn. The liquor ratio of the open-width cheese yarn is 20%;

[0059] (2) Preliminary color fixation and post-treatment: Place the open-width cheese yarn obtained in step (1) in a steamer and perform steam color fixation treatment using saturated steam. The temperature for steam color fixation is 130 °C and the time is 30 min. After the steam color fixation is completed, put it into a cheese yarn dyeing machine for reduction cleaning and water washing. During the reduction cleaning process, use reduction cleaning agent RC-200, and the dosage of the reduction cleaning agent is 1 g / L. The temperature for reduction cleaning is 80 °C and the time is 20 min. After the water washing is completed, perform dehydration and drying to obtain the polyimide pre-dyed yarn;

[0060] (3) Deepening dyeing: Inject the cationic dye solution into the material tank of the coloring device. The polyimide pre-dyed yarn is saturated with the cationic dye solution again during the winding process. The winding speed is 400 m / min, and then it undergoes extrusion and coating treatment to wind into an open-width cheese yarn. The liquor ratio of the open-width cheese yarn is 40%;

[0061] (4) Deepening color fixation and post-treatment: Place the open-width cheese yarn obtained in step (3) in a steamer and perform steam color fixation treatment using saturated steam. The temperature for steam color fixation is 140 °C and the time is 50 min. After the steam color fixation is completed, send it into a cheese yarn dyeing machine for soaping and water washing. During the soaping process, use soaping agent PERMULSIN-553, and the dosage of the soaping agent is 3 g / L. The temperature for soaping is 105 °C and the time is 30 min. After the water washing is completed, perform dehydration and drying to obtain the double-dyed polyimide yarn;

[0062] The described disperse dye solution includes disperse red RS-WF, dispersant RDT-35, and penetrant WA-M. Among them, the concentration of disperse red RS-WF is 3 wt.%, the concentration of dispersant RDT-35 is 0.1 wt.%, and the concentration of penetrant WA-M is 0.5 wt.%. Use neutralizing acid AB acid to adjust the pH value of the disperse dye solution to 4;

[0063] The described cationic dye solution includes cationic red RFBL and penetrant WA-M. Among them, the concentration of cationic red RFBL is 10 wt.%, and the concentration of penetrant WA-M is 1 wt.%. Use glacial acetic acid to adjust the pH value of the cationic dye solution to 4.

[0064] Comparative Example 1

[0065] The difference from Example 1 is that steps (3) and (4) are not included, and the others are the same as Example 1.

[0066] Comparative Example 2

[0067] The difference from Example 2 is that the temperature for steam color fixation in step (2) is 120 °C, and the others are the same as Example 2.

[0068] Comparative Example 3

[0069] The difference from Example 3 is that the winding speed in step (3) is 850 m / min, and the others are the same as in Example 3.

[0070] Performance tests were carried out on the polyimide yarns prepared in Examples 1 to 3 and Comparative Examples 1 to 3 respectively. The test methods are as follows:

[0071] Dry rubbing color fastness (grade): Tested with reference to GB / T 3920-2008;

[0072] Wet rubbing color fastness (grade): Tested with reference to GB / T 3920-2008;

[0073] Soaping color fastness (grade): Tested with reference to GB / T 3921-2008;

[0074] The K / S value of the yarn was measured using a datacolor600 spectrophotometer.

[0075] The test results are shown in Table 1.

[0076] Table 1 Performance test results

[0077]

[0078] It can be seen from the test data in Table 1 that compared with Comparative Example 1, Comparative Example 2 and Comparative Example 3 respectively, the K / S values of the polyimide yarns prepared in Example 1, Example 2 and Example 3 are higher, indicating that the method for double-dyeing polyimide yarns of the present invention has a significant effect on improving the dyeing depth of polyimide yarns.

[0079] In Comparative Example 1, since the deepening dyeing of the polyimide yarn was not carried out, the K / S value of the yarn was small and the color was light; since the steaming and fixing process was only carried out once during the dyeing process, its dry and wet rubbing color fastness and soaping color fastness were inferior to those of Example 1.

[0080] In Comparative Example 2, since the temperature of the preliminary fixing was reduced, its dry and wet rubbing color fastness and soaping color fastness decreased, and the dyeing depth of the yarn was inferior to that of Example 2.

[0081] In Comparative Example 3, since the winding speed during the deepening dyeing was increased, the contact time between the yarn and the dye liquor became shorter, resulting in the dyeing depth of the yarn being inferior to that of Example 3, but the color of the yarn became lighter, and its wet rubbing color fastness was better than that of Example 3.

Claims

1. A method for dyeing polyimide yarn with double dyes, characterized in that: The following steps are involved: (1) Preliminary dyeing: The disperse dye solution is injected into the material tank of the coloring device. The polyimide yarn is saturated with the disperse dye solution during the winding process, and then it is squeezed and coated to finally be wound into a loose cone yarn; (2) Preliminary color fixation and post-treatment: placing the loose bobbin yarn obtained in step (1) in a steamer and performing a steaming color fixation treatment using saturated steam at a temperature of 130-140° C. After the steaming color fixation is completed, placing the bobbin yarn in a bobbin dyeing machine for reduction cleaning and water washing. After the water washing is completed, dehydration and drying are performed to obtain polyimide primary dyed yarn; (3) Darkening dyeing: The cationic dye solution is injected into the material tank of the coloring device. The polyimide primary dyed yarn is saturated with the cationic dye solution again during the winding process. The winding speed is 400-800 m / min. After that, it is squeezed and coated to form a loose cone yarn. (4) Darkening and fixing and post-treatment: The loose bobbin yarn obtained in step (3) is placed in a steamer and subjected to steaming and fixing treatment using saturated steam. After the steaming and fixing treatment is completed, the bobbin yarn is sent to a bobbin dyeing machine for soaping and washing. After the washing is completed, the bobbin yarn is dehydrated and dried to obtain a double-dye-dyed polyimide yarn. The disperse dye solution comprises disperse dye, dispersant and penetrant, wherein the concentration of disperse dye is 1-7wt.%, the concentration of dispersant is 0.1-0.2wt.%, and the concentration of penetrant is 0.5-1wt.%; The cationic dye solution comprises a cationic dye and a penetrant, wherein the concentration of the cationic dye is 1-10wt.%, and the concentration of the penetrant is 0.5-1wt.%.

2. The method for dyeing polyimide yarn with double dyes according to claim 1, characterized in that: The pH value of the disperse dye solution is 4-5.

3. The method for dyeing polyimide yarn with double dyes according to claim 1, characterized in that: The pH value of the cationic dye solution is 4-5, and glacial acetic acid is used to adjust the pH value.

4. The method for dyeing polyimide yarn with double dyes according to claim 1, characterized in that: The coloring device is a single yarn online coating device.

5. The method for dyeing polyimide yarn with double dyes according to claim 1, characterized in that: In the step (1), the winding speed is 400-800 m / min, and the liquid carrying rate of the loose bobbin yarn is 20-30%.

6. The method for dyeing polyimide yarn with double dyes according to claim 1, characterized in that: In the step (2), the steaming fixation time is 30 to 50 minutes.

7. The method for dyeing polyimide yarn with double dyes according to claim 1, characterized in that: In the step (2), a non-ionic reducing cleaning agent is used for reduction cleaning, the amount of the reducing cleaning agent is 1-2 g / L, the temperature of the reducing cleaning is 80-90° C., and the time is 20-30 min.

8. The method for dyeing polyimide yarn with double dyes according to claim 1, characterized in that: In the step (3), the liquid carrying rate of the loose bobbin yarn is 30-40%.

9. The method for dyeing polyimide yarn with double dyes according to claim 1, characterized in that: In the step (4), the temperature of steaming and fixing is 130-140°C and the time is 30-50 minutes.

10. The method for dyeing polyimide yarn with double dyes according to claim 1, characterized in that: In the step (4), anionic soaping agent is used for soaping, the amount of soaping agent is 1-3 g / L, the temperature of soaping is 80-105° C., and the time is 20-30 min.

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