Method for dyeing polyimide yarns by using double dyes

Abstract

The invention belongs to the technical field of textile printing and dyeing, and particularly relates to a method for dyeing polyimide yarn with double dyes. Comprising the following steps: (1) injecting dispersed dye liquor into a coloring device, adsorbing the dispersed dye liquor by polyimide yarns in a winding process, and winding the polyimide yarns into loose cone yarns after extrusion and coating treatment; (2) performing steaming color fixation treatment on the slack cone yarns in the step (1), then performing reduction cleaning and water washing, dehydrating and drying to obtain polyimide primarily-dyed yarns; (3) the cationic dye liquor is injected into a coloring device, the polyimide primarily-dyed yarn adsorbs the cationic dye liquor in the winding process, and the polyimide primarily-dyed yarn is wound into loose cone yarn after being extruded and smeared; (4) performing steaming color fixation treatment on the slack cone yarns in the step (3), then performing soaping and water washing, and performing dehydration and drying to obtain double-dye dyed polyimide yarns; a two-step dyeing process is adopted, firstly, the disperse dye is used for primary dyeing, then the cationic dye is used for deepening dyeing, and the prepared polyimide dyed yarn is high in dyeing depth and good in dyeing fastness.

Description

Technical Field

[0001] The invention belongs to the technical field of textile printing and dyeing, and particularly relates to a method for double-dye dyeing polyimide yarn. Background Art

[0002] Polyimide fiber (PI) refers to a fiber containing aromatic imide in the molecular chain. It can generally be made by the polycondensation reaction of anhydride and aromatic diisocyanate in solvents such as dimethylamide, and then spinning. Polyimide fiber has many excellent properties, such as good spinnability, flame retardancy, excellent thermal insulation performance, non-melting droplet characteristics, self-extinguishing ability, 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 sanitary protective clothing, special clothing for anti-biological and chemical weapons, racing flame-proof clothing, aerospace suits, and high-efficiency smoke protection masks. Polyimide fabrics also have excellent dimensional stability and safety, and long service life. However, due to the high conjugation of the molecular main chain structure of polyimide fiber, its molecular orientation is high, the glass transition temperature is high, and the fiber itself is golden yellow. These factors make polyimide fibers face problems such as low dye uptake and poor deep dyeing ability during dyeing and finishing, thus limiting their development and application in the textile and clothing field.

[0003] At present, the main dyeing methods for polyimide fibers include carrier dyeing, fiber pretreatment dyeing and solvent dyeing. Chinese patent CN107287933A discloses a dyeing method for polyimide fibers or polyimide fabrics. This method has a high dye uptake 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 fibers. The fibers are pretreated with an alkaline pretreatment liquid. This method enhances the dyeing performance of the fibers, but affects the mechanical properties of the fibers to a certain extent. Chinese patent CN106087379A discloses a waterless dyeing method for polyimide fabrics. Dispersed dyes are used to dye polyimide fabrics in supercritical carbon dioxide. The dyed fabric has a high color depth and good color fastness, but this method has a relatively high process difficulty. After dyeing, the dispersed dyes and carbon dioxide need to be recovered separately, which makes it difficult to achieve mass production. Summary of the invention

[0004] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a method for double-dye dyeing polyimide yarn, which adopts a two-step dyeing process, firstly using disperse dyes for preliminary dyeing, and then using cationic dyes for deepening dyeing. The obtained polyimide dyed yarn has a high dyeing depth and good color fastness; the dyeing process is carried out at room temperature, without the need for pretreatment of the yarn, effectively reducing the strength loss of the yarn, reducing energy consumption, being green and environmentally friendly, and easy for industrial production.

[0005] The technical solution adopted by the present invention is as follows: The method for dyeing polyimide yarn with double dyes comprises the following steps: (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-type cone yarn obtained in step (1) in a steamer for steaming color fixation treatment. After the steaming color fixation is completed, placing it in a cone 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, and then 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 for steaming and fixing. After the steaming and fixing is completed, it is sent to a bobbin dyeing machine for soaping and washing. After the washing is completed, it 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.%.

[0006] The pH value of the disperse dye solution is 4-5, and the pH value is adjusted by using a neutralizing acid, which is an aqueous dispersion of an organic acid and a dispersant.

[0007] The pH value of the cationic dye solution is 4-5, and glacial acetic acid is used to adjust the pH value.

[0008] The coloring device is a single yarn online coating device in Chinese patent CN116716734A. The dye solution is added into the material tank of the single yarn online coating device. The operation of the device is used to transfer the polyimide yarn through the liquid wheel to absorb the dye solution, and then the dye solution is coated by the extrusion device and wound into a loose cone yarn.

[0009] 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%.

[0010] In the step (2), the temperature of steaming and fixing is 130-140° C., and the time is 30-50 min.

[0011] In the step (2), a non-ionic reducing cleaning agent is used for reduction cleaning. The non-ionic reducing cleaning agent is neutral or acidic. 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.

[0012] In the step (3), the winding speed is 400-800 m / min, and the liquid carrying rate of the loose bobbin yarn is 30-40%.

[0013] In the step (4), the temperature of steaming and fixing is 130-140°C and the time is 30-50 minutes.

[0014] 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.

[0015] Compared with the prior art, the present invention has the following beneficial effects: (1) The method for dyeing polyimide yarn with double dyes of the present invention does not require yarn pretreatment, and does not require the use of a carrier during the dyeing process, making the production process more environmentally friendly; (2) The present invention adopts a two-step dyeing method, firstly using disperse dyes for preliminary dyeing, and then using cationic dyes for deepening dyeing, so that the obtained polyimide yarn has high dyeing depth and good dyeing fastness; (3) The dyeing process of the present invention is carried out at room temperature, and the color fixing process is carried out using steam under non-water bath conditions. The yarn strength loss is small, the energy consumption is low, the requirements for production equipment are low, and the production efficiency is high, which is suitable for industrial production. DETAILED DESCRIPTION

[0016] The present invention is further described below with reference to the embodiments, but they do not limit the implementation of the present invention.

[0017] The raw materials used in the examples and comparative examples are conventional commercially available raw materials unless otherwise specified, and the process methods used in the examples and comparative examples are conventional methods in the art unless otherwise specified.

[0018] Some of the raw materials used in the examples and comparative examples are described as follows: Disperse blue BE-RPD was purchased from Sumitomo Chemical (Shanghai) Co., Ltd.; Disperse black BKSWF, purchased from Yorkshire (China) Trading Co., Ltd.; Disperse Red RS-WF was purchased from Archroma Chemicals (China) Co., Ltd. Cationic blue BFGRL was purchased from DyStar (Shanghai) Trading Co., Ltd.; Cationic black BKFDL, purchased from DyStar (Shanghai) Trading Co., Ltd.; Cationic red RFBL was purchased from DyStar (Shanghai) Trading Co., Ltd.; Dispersant RDT-35 was purchased from Shanghai Xintian Economic and Trade Co., Ltd.; Penetrant WA-M was purchased from Zibo Lurui Fine Chemical Co., Ltd.; Neutralizing acid AB acid was purchased from Tona Trading (Shanghai) Co., Ltd.; Reducing cleaning agent RC-200 was purchased from Doen Biotechnology Co., Ltd.; Soaping agent PERMULSIN-553 was purchased from Boset (Ningbo) Chemical Co., Ltd.

[0019] Example 1 The method for dyeing polyimide yarn with double dyes comprises the following steps: (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. The winding speed is 800 m / min. After extrusion and coating, the yarn is finally wound into a loose bobbin with a liquid content of 20%. (2) Preliminary color fixation and post-treatment: the loose bobbin yarn obtained in step (1) is placed in a steamer and subjected to steaming color fixation treatment using saturated steam at a temperature of 130°C for 30 min. After the steaming color fixation is completed, the bobbin yarn is placed in a bobbin dyeing machine for reduction cleaning and water washing, wherein the reduction cleaning agent RC-200 is used in an amount of 1 g / L, the reduction cleaning temperature is 80°C for 20 min, and the water washing is completed. After the water washing is completed, the bobbin yarn is dehydrated and dried to obtain polyimide primary dyed yarn. (3) Darkening dyeing: cationic dye solution is injected into the material tank of the coloring device. The polyimide primary dyed yarn is saturated with cationic dye solution again during the winding process. The winding speed is 800 m / min. After that, it is squeezed and coated to form a loose bobbin yarn. The liquid carrying rate of the loose bobbin yarn is 30%; (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 at a temperature of 130°C for 30 min. After the steaming and fixing is completed, the bobbin yarn is sent to a bobbin dyeing machine for soaping and water washing, wherein the soaping process uses a soaping agent PERMULSIN-553 at a dosage of 1 g / L, at a soaping temperature of 80°C for 20 min. After the water washing is completed, the bobbin yarn is dehydrated and dried to obtain a double-dye dyed polyimide yarn. The disperse dye solution comprises disperse blue BE-RPD, dispersant RDT-35 and penetrant WA-M, wherein the concentration of disperse blue BE-RPD is 1wt.%, the concentration of dispersant RDT-35 is 0.1wt.%, the concentration of penetrant WA-M is 0.5wt.%, and the pH value of the disperse dye solution is adjusted to 5 by neutralizing acid AB acid; The cationic dye solution comprises cationic blue BFGRL and penetrant WA-M, wherein the concentration of cationic blue BFGRL is 1wt.%, the concentration of penetrant WA-M is 0.5wt.%, and glacial acetic acid is used to adjust the pH value of the cationic dye solution to 5.

[0020] Example 2 The method for dyeing polyimide yarn with double dyes comprises the following steps: (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. The winding speed is 600 m / min. After extrusion and coating, the yarn is finally wound into a loose bobbin with a liquid content of 25%. (2) Preliminary color fixation and post-treatment: the loose bobbin yarn obtained in step (1) is placed in a steamer and subjected to steaming color fixation treatment using saturated steam at a temperature of 140°C for 35 min. After the steaming color fixation is completed, the bobbin yarn is placed in a bobbin dyeing machine for reduction cleaning and water washing, wherein the reduction cleaning agent RC-200 is used in an amount of 2 g / L, the reduction cleaning temperature is 90°C for 30 min, and the water washing is completed. After the water washing is completed, the bobbin yarn is dehydrated and dried to obtain polyimide primary dyed yarn. (3) Darkening dyeing: cationic dye solution is injected into the material tank of the coloring device. The polyimide primary dyed yarn is saturated with cationic dye solution again during the winding process. The winding speed is 600 m / min. After that, it is squeezed and coated to form a loose bobbin yarn. The liquid carrying rate of the loose bobbin yarn is 35%; (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 at a temperature of 135°C for 35 min. After the steaming and fixing is completed, the bobbin yarn is sent to a bobbin dyeing machine for soaping and water washing, wherein the soaping process uses a soaping agent PERMULSIN-553 at a dosage of 2 g / L, at a soaping temperature of 90°C for 20 min. After the water washing is completed, the bobbin yarn is dehydrated and dried to obtain a double-dye dyed polyimide yarn. The disperse dye solution comprises disperse black BKSWF, dispersant RDT-35 and penetrant WA-M, wherein the concentration of disperse black BKSWF is 7wt.%, the concentration of dispersant RDT-35 is 0.2wt.%, and the concentration of penetrant WA-M is 1wt.%, and the pH value of the disperse dye solution is adjusted to 4 by neutralizing acid AB acid; The cationic dye solution comprises cationic black BKFDL and penetrant WA-M, wherein the concentration of cationic black BKFDL is 5wt.%, the concentration of penetrant WA-M is 0.5wt.%, and the pH value of the cationic dye solution is adjusted to 4 by using glacial acetic acid.

[0021] Example 3 The method for dyeing polyimide yarn with double dyes comprises the following steps: (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. The winding speed is 700 m / min. After extrusion and coating, the yarn is finally wound into a loose bobbin with a liquid content of 20%. (2) Preliminary color fixation and post-treatment: the loose bobbin yarn obtained in step (1) is placed in a steamer and subjected to steaming color fixation treatment using saturated steam at a temperature of 130°C for 30 min. After the steaming color fixation is completed, the bobbin yarn is placed in a bobbin dyeing machine for reduction cleaning and water washing, wherein the reduction cleaning agent RC-200 is used in an amount of 1 g / L, the reduction cleaning temperature is 80°C for 20 min, and the water washing is completed. After the water washing is completed, the bobbin yarn is dehydrated and dried to obtain polyimide primary dyed yarn. (3) Darkening dyeing: cationic dye solution is injected into the material tank of the coloring device. The polyimide primary dyed yarn is saturated with cationic dye solution again during the winding process. The winding speed is 400 m / min. After that, it is squeezed and coated to form a loose bobbin yarn. The liquid carrying rate of the loose bobbin yarn is 40%; (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 at a temperature of 140°C for 50 min. After the steaming and fixing is completed, the bobbin yarn is sent to a bobbin dyeing machine for soaping and water washing, wherein the soaping agent PERMULSIN-553 is used in the soaping process, the amount of the soaping agent is 3 g / L, the soaping temperature is 105°C, and the time is 30 min. After the water washing is completed, the bobbin yarn is dehydrated and dried to obtain a double-dye dyed polyimide yarn. The disperse dye solution comprises disperse red RS-WF, dispersant RDT-35 and penetrant WA-M, wherein the concentration of disperse red RS-WF is 3wt.%, the concentration of dispersant RDT-35 is 0.1wt.%, the concentration of penetrant WA-M is 0.5wt.%, and the pH value of the disperse dye solution is adjusted to 4 by neutralizing acid AB acid; The cationic dye solution comprises cationic red RFBL and penetrant WA-M, wherein the concentration of cationic red RFBL is 10wt.%, the concentration of penetrant WA-M is 1wt.%, and the pH value of the cationic dye solution is adjusted to 4 by using glacial acetic acid.

[0022] Comparative Example 1 The difference from Example 1 is that step (3) and step (4) are not included, and the rest is the same as Example 1.

[0023] Comparative Example 2 The difference from Example 2 is that the temperature of steaming and fixing in step (2) is 120° C., and the rest is the same as Example 2.

[0024] Comparative Example 3 The difference from Example 3 is that the winding speed in step (3) is 850 m / min, and the rest is the same as Example 3.

[0025] The performance tests of the polyimide yarns prepared in Examples 1 to 3 and Comparative Examples 1 to 3 were performed respectively, and the test methods were as follows: Color fastness to dry rubbing (grade): Tested in accordance with GB / T 3920-2008; Color fastness to wet rubbing (grade): Tested in accordance with GB / T 3920-2008; Color fastness to soap washing (grade): Tested in accordance with GB / T 3921-2008; The K / S value of the yarn was measured using a datacolor 600 spectrophotometer.

[0026] The test results are shown in Table 1.

[0027] Table 1 Performance test results

[0028] It can be seen from the test data in Table 1 that, compared with Comparative Example 1, Comparative Example 2 and Comparative Example 3, the K / S values ​​of the polyimide yarns prepared in Example 1, Example 2 and Example 3 are high, respectively, indicating that the method for double-dye dyeing polyimide yarns described in the present invention has a significant effect on improving the dyeing depth of polyimide yarns.

[0029] In Comparative Example 1, since the polyimide yarn was not dyed darker, the yarn K / S value was small and the color was lighter; since only one steaming fixation was performed during the dyeing process, its color fastness to dry and wet friction and color fastness to soap washing were not as good as those in Example 1.

[0030] In Comparative Example 2, since the temperature of the initial color fixation was lowered, the color fastness to dry and wet friction and the color fastness to soap washing decreased, and the yarn dyeing depth was not as good as that in Example 2.

[0031] In Comparative Example 3, since the winding speed during darkening dyeing is increased, the contact time between the yarn and the dye solution is shortened, resulting in the yarn dyeing being not as dark as in Example 3, but the yarn color becomes lighter, and its wet friction color fastness is better than that in 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-type cone yarn obtained in step (1) in a steamer for steaming color fixation treatment at a temperature of 130-140° C. After the steaming color fixation is completed, placing the cone yarn in a cone 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 for steaming and fixing. After the steaming and fixing is completed, it is sent to a bobbin dyeing machine for soaping and washing. After the washing is completed, it 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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