A waterless dyeing method for polyphenylene sulfoxide fiber

Abstract

The invention relates to the field of textiles and provides a waterless dyeing method for polyphenylsulfone sulfoxide fibers, which solves the defects of the prior art water dyeing method, namely, being environmentally unfriendly, energy-consuming, water-inefficient, and requiring the use of auxiliaries. The method comprises the following processing steps: opening a condenser, loading a dye kettle, loading a dyeing kettle, increasing pressure and temperature, dyeing, recycling, cleaning, sampling, and testing.

Description

Technical Field

[0001] The invention relates to the field of textiles, in particular to a waterless dyeing method for polyphenylsulfone sulfoxide fibers. Background Art

[0002] Supercritical carbon dioxide fluid has been widely used as a green solvent in the textile industry, particularly in the dyeing of synthetic fibers. The waterbath dyeing process for synthetic fibers produces large amounts of contaminated wastewater containing various dispersants, surfactants, and unused dyes. Improper treatment of this wastewater can cause severe environmental pollution. Applying supercritical carbon dioxide fluid dyeing technology to synthetic fiber dyeing not only reduces overall dyeing costs but also prevents environmental pollution from post-dyeing emissions.

[0003] During the supercritical CO2 dyeing process, the mobility of the fiber's amorphous molecular chains increases in the supercritical CO2 fluid, increasing the amorphous region content and pore size within the fiber. Under the same dyeing conditions, this effect is more significant than with water. Simultaneously, the excellent fluidity and diffusivity of the supercritical CO2 fluid facilitates the diffusion of the dye into the fiber in a single-molecule state, completing the dyeing process. The supercritical CO2 dyeing process requires no auxiliaries, and the CO2 is non-toxic and recyclable. Residual dye can be recovered in powder form, eliminating wastewater and waste, and eliminating the need for post-dyeing treatment and drying, saving approximately 80% energy. This process is several times faster than traditional methods, achieving high dyeing efficiency.

[0004] As can be seen from the above, supercritical carbon dioxide dyeing is an efficient and environmentally friendly dyeing process. Therefore, the application of supercritical carbon dioxide dyeing technology in the printing and dyeing industry is feasible and has great development potential.

[0005] As a structural modification material for polyphenylene sulfide fibers, the modified polyphenylene sulfoxide fibers introduce highly polar sulfone groups (-SO2-) into the molecular chain, transforming them into a non-crystalline polymer with a glass transition temperature (Tg) as high as 215°C. This overcomes the shortcomings of polyphenylene sulfide, such as its low glass transition temperature (Tg = 85°C), poor toughness, and brittleness. For example, CN105113209A discloses a method for preparing self-extinguishing and drip-free PPS fibers. This method uses pure polyphenylene sulfide fibers as raw material, immersing them in an oxidant solution. By selecting the oxidant type, controlling the immersion temperature and time, the degree of oxidation of sulfur atoms on the fiber surface is regulated. After the reaction is complete, the fibers are separated by solvent, and the PPS fibers are washed and dried. The resulting PPS fibers exhibit significantly improved antioxidant, high-temperature, creep, and drip resistance properties. CN 115637582A discloses a method for preparing polyphenylene sulfoxide fibers by ozone-hydrogen peroxide synergistic heterogeneous oxidation. This method uses polyphenylene sulfide (PPS) fiber as a raw material, mixes it with deionized water, an activator, hydrogen peroxide, and an acidity regulator to form a mixture, then heats the mixture to a certain temperature under self-circulating conditions, continuously introduces ozone into the mixture, and reacts at a certain temperature. The residual liquid on the surface of the resulting fiber is removed, and the fiber is dried to obtain polyphenylene sulfoxide (PPSSO) fiber. The PPSSO fiber prepared by the present invention has no melting point and has excellent oxidation resistance, high temperature resistance, and acid and alkali resistance.

[0006] Polyphenylsulfoxide (PSS) fibers offer superior mechanical properties, high-temperature resistance, dimensional stability, corrosion resistance, flame retardancy, and electrical properties. This makes them promising for applications in environmental protection, military, electrical engineering, machinery, aviation, and other fields. As high-temperature, flame-retardant fibers, they can also be used in specialized industries such as protective clothing, workwear, and interior decoration for public buildings and vehicles. However, most textile products used in these applications require dyeing.

[0007] Since polyphenylsulfone sulfoxide fiber has no hydrophilic groups such as hydroxyl and amino groups on its macromolecular chain, nor reactive groups that can interact with dye molecules, it is highly hydrophobic and has a high glass transition temperature. However, since the temperature during water bath dyeing does not reach the glass transition temperature of polyphenylsulfone sulfoxide fiber, the dye cannot fully penetrate the fiber to achieve a good dyeing effect. Therefore, it is difficult to dye polyphenylsulfone sulfoxide fiber under conventional water bath dyeing conditions and the dyeing effect is very poor.

[0008] Disperse dyes generally have the characteristics of weak molecular polarity and small molecular weight. The solubility of supercritical carbon dioxide fluid in organic matter varies with the solute polarity, molecular weight, density, etc. It can easily dissolve non-polar or weakly polar, small molecular weight organic matter. Therefore, disperse dyes are easily soluble in supercritical carbon dioxide fluid. The swelling effect of supercritical carbon dioxide fluid on fiber materials can also promote the dye to enter the interior of the fiber to achieve better dyeing effect.

[0009] Compared with polyphenylene sulfide fibers, polyphenylene sulfoxide fibers are more difficult to dye, and there is currently no report on dyeing technology and methods for polyphenylene sulfoxide fibers or fabrics. Summary of the Invention

[0010] Therefore, in order to solve the above problems, the present invention provides a waterless dyeing method for polyphenylene sulfone sulfoxide fibers, which solves the defects of the prior art water dyeing method, such as being environmentally unfriendly, energy-consuming, water-inefficient, and requiring the use of auxiliaries.

[0011] To achieve the above object, the present invention adopts the following technical solution: a waterless dyeing method for polyphenylene sulfoxide fiber, comprising the following processing steps: opening a condenser, charging a dye kettle, charging a dye kettle, increasing pressure and temperature, and dyeing;

[0012] Among them, the purpose of opening the condenser is to condense carbon dioxide into liquid, in preparation for the subsequent pressurization of the dyeing kettle;

[0013] The dye kettle loading process is to add disperse dye into the dye kettle;

[0014] The dyeing kettle loading process is to load the sample to be dyed into the dyeing kettle;

[0015] The pressure and temperature raising process is to open the carbon dioxide inlet valve on the dye kettle, and the carbon dioxide gas passes through the refrigerator and then enters the dyeing kettle through an additional pump or a high-pressure pump, and then the temperature is raised to make the carbon dioxide enter a supercritical state;

[0016] The dyeing process is to perform supercritical carbon dioxide fluid dynamic circulation dyeing on the sample in the dyeing kettle, the dyeing conditions are to maintain the temperature at 110-180°C, the pressure at 22-30 MPa, the time at 45-80 min, and the dye dosage at 2-6%, calculated based on the weight ratio of the dye to the sample to be dyed;

[0017] Furthermore: the disperse dye contains at least one of the five dyes of Disperse Red 86, Disperse Red 92, Disperse Red 137, Disperse Yellow 114 and Disperse Yellow M-FL, and the mass proportion of other disperse dyes in the total amount of dyes added is ≤40%.

[0018] Furthermore: it also includes a recovery process, which is to open the valve of the dye recovery kettle, and allow the supercritical carbon dioxide fluid carrying the dye to enter the dye recovery kettle. After cooling and reducing pressure, the solubility of the dye decreases and remains in the dye recovery kettle, and the carbon dioxide is converted into gas and recovered.

[0019] Furthermore: it also includes a cleaning process, which is to close the dye kettle, introduce clean carbon dioxide fluid, and wash away the dye attached to the fiber surface and the dyeing device and pipeline.

[0020] Furthermore, the method further includes a sampling process. After the cleaning process is completed, when the temperature of the dye kettle, dyeing kettle and dye recovery kettle reaches 25-40°C and the pressure is released to normal pressure, the dyeing kettle is opened to take out the sample.

[0021] Furthermore: it also includes an inspection process, which is to measure the color fastness to soaping, dyeing depth K / S value and various fastness properties of the dyed polyphenylsulfone sulfoxide fiber according to national standards.

[0022] By adopting the above technical solution, the beneficial effects of the present invention are:

[0023] 1. The present invention uses supercritical carbon dioxide fluid as the dyeing medium during the dyeing process and adopts a cyclic dynamic dyeing method, which saves a large amount of water resources and does not produce sewage or wastewater after the dyeing is completed, achieving pollution-free and clean dyeing. After the dyeing is completed, there is no need for washing, dehydration or drying, which saves electricity and energy.

[0024] 2. The polyphenylsulfone sulfoxide fiber dyed with supercritical carbon dioxide fluid of the present invention has high color fastness and depth, and the color fastness to soaping and the color fastness to rubbing both reach level 4 (including level 4) or above, and the K / S value reaches 4.5 or above.

[0025] 3. The polyphenylene sulfoxide fiber dyed with supercritical carbon dioxide fluid in the present invention has no effect on the fiber properties compared with the fiber before dyeing, and its fiber breaking strength value remains basically unchanged. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 Schematic diagram of the structure of the dyeing system in Example 1 of the present invention.

[0027] Explanation of icons: 1-CO2 gas storage tank; 2-first purifier; 3-first condenser; 4-high-pressure pump; 5-heat exchanger; 6-dye kettle; 7-dyeing kettle; 8-dye recovery kettle; 9-circulation pump; 10-second condenser; 11-recovery pump; 12-second purifier. DETAILED DESCRIPTION

[0028] For the convenience of understanding the present invention, the present invention is given below with examples. It should be understood by those skilled in the art that the examples are only for the purpose of helping to understand the present invention and should not be regarded as specific limitations of the present invention.

[0029] The dyeing performance test of the fibers in each embodiment follows the following method:

[0030] Color fastness to washing with soap: Tested in accordance with GB / T 3921-2008 Textiles - Tests for color fastness - Color fastness to washing with soap;

[0031] Color fastness to rubbing: Tested in accordance with GB / T 3920-2008 Textiles - Tests for color fastness to rubbing;

[0032] Dyeing depth K / S value: tested in accordance with GB / T 6688-2008 instrumental method for determination of relative strength and color difference of dyes.

[0033] Fiber breaking strength: Tested in accordance with GB / T 14337-2022 Test method for tensile properties of short fibers, with reference to the values ​​listed for pre-tension of polyphenylene sulfide fibers.

[0034] Example 1

[0035] refer to Figure 1 , a waterless dyeing method for polyphenylsulfone sulfoxide fiber, the process of which includes:

[0036] Open the first condenser → load the dye kettle → load the dye kettle → increase pressure and temperature → dye → recycle → clean → take samples → inspect.

[0037] The carbon dioxide in the CO2 gas tank 1 is purified by the first purifier 2 and then condensed into liquid by the first condenser 3, in preparation for the subsequent pressurization in the dyeing kettle 7;

[0038] Add disperse dye Disperse Red 86 into dye kettle 6;

[0039] The polyphenylene sulfoxide fiber sample to be dyed is placed in the dyeing kettle 7;

[0040] Open the carbon dioxide inlet valve on the dye kettle 6. After the carbon dioxide gas passes through the refrigerator, it first enters the dyeing kettle 7 through the high-pressure pump 4, and then passes through the heat exchanger 5 to increase the temperature so that the carbon dioxide enters a supercritical state.

[0041] Turn on the circulation pump 9 to perform supercritical carbon dioxide fluid dynamic circulation dyeing on the sample in the dyeing kettle 7. The dyeing conditions are maintained at a temperature of 145° C. and a pressure of 25 MPa. The timing is started after the set conditions are reached. The time is 60 minutes and the dye dosage is 5% (owf).

[0042] After dyeing is completed, the valve of the dye recovery kettle 8 is opened, and the supercritical carbon dioxide fluid carrying the dye enters the dye recovery kettle 8. After cooling and reducing pressure, the solubility of the dye decreases and remains in the dye recovery kettle 8. The carbon dioxide turns into gas and is recovered. Specifically, the carbon dioxide is purified by the second purifier 12, condensed by the second condenser 10, and then recovered by the recovery pump 11.

[0043] Close the dye kettle 6 and introduce clean carbon dioxide fluid to wash away the dye attached to the fiber surface and the dyeing device and pipeline;

[0044] After the cleaning process is completed, when the temperature of the dye kettle, dyeing kettle and dye recovery kettle reaches 40°C and the pressure is released to normal pressure, open the dyeing kettle and take out the sample.

[0045] The test results of the dyed polyphenylene sulfoxide fiber are shown in Table 1.

[0046] Example 2

[0047] A waterless dyeing method for polyphenylsulfone sulfoxide fibers, the process of which comprises:

[0048] Open the condenser → load the dye kettle → load the dye kettle → increase the pressure and temperature → dye → recycle → clean → take samples → inspect.

[0049] Open the condenser to condense the carbon dioxide into liquid, in preparation for the subsequent pressurization of the dyeing kettle;

[0050] Add disperse dye Disperse Yellow 114 into the dye kettle;

[0051] The polyphenylene sulfoxide fiber sample to be dyed is placed in the dyeing kettle;

[0052] Open the CO2 inlet valve on the dye kettle. After the CO2 gas passes through the refrigerator, it first enters the dyeing kettle through a high-pressure pump, and then is heated by a heat exchanger to make the CO2 enter a supercritical state.

[0053] Turn on the circulation pump to perform supercritical carbon dioxide fluid dynamic circulation dyeing on the sample in the dyeing kettle. The dyeing conditions are maintained at 180°C and 30 MPa. When the set conditions are reached, the timing starts, the time is 45 minutes, and the dye dosage is 6% (owf);

[0054] After dyeing is completed, the valve of the dye recovery kettle is opened, and the supercritical carbon dioxide fluid carrying the dye enters the dye recovery kettle. After cooling and reducing pressure, the solubility of the dye decreases and remains in the kettle, and the carbon dioxide turns into gas and is recovered;

[0055] Close the dye kettle and introduce clean carbon dioxide fluid to wash away the dye attached to the fiber surface and the dyeing device and pipeline;

[0056] After the cleaning process is completed, when the temperature of the dye kettle, dyeing kettle and recovery kettle reaches 35°C and the pressure is released to normal pressure, open the dyeing kettle and take out the sample.

[0057] The test results of the dyed polyphenylene sulfoxide fiber are shown in Table 1.

[0058] Example 3

[0059] A waterless dyeing method for polyphenylsulfone sulfoxide fibers, the process of which comprises:

[0060] Open the condenser → load the dye kettle → load the dye kettle → increase the pressure and temperature → dye → recycle → clean → take samples → inspect.

[0061] Open the condenser to condense the carbon dioxide into liquid, in preparation for the subsequent pressurization of the dyeing kettle;

[0062] Add disperse dye Disperse Red 92 into the dye kettle;

[0063] The polyphenylene sulfoxide fiber sample to be dyed is placed in the dyeing kettle;

[0064] Open the CO2 inlet valve on the dye kettle. After the CO2 gas passes through the refrigerator, it first enters the dyeing kettle through a high-pressure pump, and then is heated by a heat exchanger to make the CO2 enter a supercritical state.

[0065] Turn on the circulation pump to perform supercritical carbon dioxide fluid dynamic circulation dyeing on the sample in the dyeing kettle. The dyeing conditions are maintained at 110°C and 22 MPa. When the set conditions are reached, the timing is started, the time is 80 minutes, and the dye dosage is 4% (owf);

[0066] After dyeing is completed, the valve of the dye recovery kettle is opened, and the supercritical carbon dioxide fluid carrying the dye enters the dye recovery kettle. After cooling and reducing pressure, the solubility of the dye decreases and remains in the kettle, and the carbon dioxide turns into gas and is recovered;

[0067] Close the dye kettle and introduce clean carbon dioxide fluid to wash away the dye attached to the fiber surface and the dyeing device and pipeline;

[0068] After the cleaning process is completed, when the temperature of the dye kettle, dyeing kettle and recovery kettle reaches 25°C and the pressure is released to normal pressure, open the dyeing kettle and take out the sample.

[0069] The test results of the dyed polyphenylene sulfoxide fiber are shown in Table 1.

[0070] Example 4

[0071] A waterless dyeing method for polyphenylsulfone sulfoxide fibers, the process of which comprises:

[0072] Open the condenser → load the dye kettle → load the dye kettle → increase the pressure and temperature → dye → recycle → clean → take samples → inspect.

[0073] Open the condenser to condense the carbon dioxide into liquid, in preparation for the subsequent pressurization of the dyeing kettle;

[0074] Add disperse dyes disperse red 137 and disperse blue 79 into the dye kettle in a mass ratio of 1:1;

[0075] The polyphenylene sulfoxide fiber sample to be dyed is placed in the dyeing kettle;

[0076] Open the CO2 inlet valve on the dye kettle. After the CO2 gas passes through the refrigerator, it first enters the dyeing kettle through a high-pressure pump, and then is heated by a heat exchanger to make the CO2 enter a supercritical state.

[0077] Turn on the circulation pump to perform supercritical carbon dioxide fluid dynamic circulation dyeing on the sample in the dyeing kettle. The dyeing conditions are maintained at 140°C and 23 MPa. When the set conditions are reached, the timing starts, the time is 70 minutes, and the total dye dosage is 3% (owf);

[0078] After dyeing is completed, the valve of the dye recovery kettle is opened, and the supercritical carbon dioxide fluid carrying the dye enters the dye recovery kettle. After cooling and reducing pressure, the solubility of the dye decreases and remains in the kettle, and the carbon dioxide turns into gas and is recovered;

[0079] Close the dye kettle and introduce clean carbon dioxide fluid to wash away the dye attached to the fiber surface and the dyeing device and pipeline;

[0080] After the cleaning process is completed, when the temperature of the dye kettle, dyeing kettle and recovery kettle reaches 40°C and the pressure is released to normal pressure, open the dyeing kettle and take out the sample.

[0081] The test results of the dyed polyphenylene sulfoxide fiber are shown in Table 1.

[0082] Example 5

[0083] A waterless dyeing method for polyphenylsulfone sulfoxide fibers, the process of which comprises:

[0084] Open the condenser → load the dye kettle → load the dye kettle → increase the pressure and temperature → dye → recycle → clean → take samples → inspect.

[0085] Open the condenser to condense the carbon dioxide into liquid, in preparation for the subsequent pressurization of the dyeing kettle;

[0086] Add disperse dyes Disperse Red 86, Disperse Yellow M-FL and Disperse Blue 79 into the dye kettle in a mass ratio of 1:1:1;

[0087] The polyphenylene sulfoxide fiber sample to be dyed is placed in the dyeing kettle;

[0088] Open the CO2 inlet valve on the dye kettle. After the CO2 gas passes through the refrigerator, it first enters the dyeing kettle through a high-pressure pump, and then is heated by a heat exchanger to make the CO2 enter a supercritical state.

[0089] Turn on the circulation pump to perform supercritical carbon dioxide fluid dynamic circulation dyeing on the sample in the dyeing kettle. The dyeing conditions are maintained at 150°C and 25 MPa. When the set conditions are reached, the timing starts, the time is 60 minutes, and the total dye dosage is 5% (owf);

[0090] After dyeing is completed, the valve of the dye recovery kettle is opened, and the supercritical carbon dioxide fluid carrying the dye enters the dye recovery kettle. After cooling and reducing pressure, the solubility of the dye decreases and remains in the kettle, and the carbon dioxide turns into gas and is recovered;

[0091] Close the dye kettle and introduce clean carbon dioxide fluid to wash away the dye attached to the fiber surface and the dyeing device and pipeline;

[0092] After the cleaning process is completed, when the temperature of the dye kettle, dyeing kettle and recovery kettle reaches 40°C and the pressure is released to normal pressure, open the dyeing kettle and take out the sample.

[0093] The test results of the dyed polyphenylene sulfoxide fiber are shown in Table 1.

[0094] Comparative Example 1

[0095] Disperse red 60 was selected as the disperse dye, and other methods and conditions were the same as those in Example 2.

[0096] Comparative Example 2

[0097] Disperse blue 79 was selected as the disperse dye, and other methods and conditions were the same as those in Example 2.

[0098] Table 1 Performance test results of polyphenylsulfone sulfoxide fiber before and after dyeing

[0099]

[0100] Although the present invention has been particularly shown and described in conjunction with preferred embodiments, it will be understood by those skilled in the art that various changes in form and details may be made to the present invention without departing from the spirit and scope of the invention as defined in the appended claims, and all such changes are within the scope of protection of the present invention.

Claims

1. A waterless dyeing method for polyphenylene sulfoxide fiber, characterized in that: The process includes the following steps: opening the condenser, loading the dye kettle, loading the dye kettle, increasing the pressure and temperature, and dyeing; Among them, the purpose of opening the condenser is to condense carbon dioxide into liquid, in preparation for the subsequent pressurization of the dyeing kettle; The dye kettle loading process is to add disperse dye into the dye kettle; The dyeing kettle loading process is to load the sample to be dyed into the dyeing kettle; The pressure and temperature raising process is to open the carbon dioxide inlet valve on the dye kettle, and the carbon dioxide gas passes through the refrigerator and then enters the dyeing kettle through an additional pump or a high-pressure pump, and then the temperature is raised to make the carbon dioxide enter a supercritical state; The dyeing process is to perform supercritical carbon dioxide fluid dynamic circulation dyeing on the sample in the dyeing kettle, the dyeing conditions are maintained at a temperature of 110-180°C, a pressure of 22-30 MPa, a time of 45-80 minutes, and a dye dosage of 2-6%, calculated based on the weight ratio of the dye to the sample to be dyed; The disperse dye contains at least one of the five dyes of disperse red 86, disperse red 92, disperse red 137, disperse yellow 114 and disperse yellow M-FL, and the mass proportion of other disperse dyes in the total amount of dyes added is ≤40%.

2. The waterless dyeing method for polyphenylene sulfoxide fiber according to claim 1, characterized in that: It also includes a recovery process, in which the valve of the dye recovery kettle is opened, and the supercritical carbon dioxide fluid carrying the dye enters the dye recovery kettle. After cooling and reducing pressure, the solubility of the dye decreases and remains in the dye recovery kettle, and the carbon dioxide is converted into gas and recovered.

3. The waterless dyeing method for polyphenylene sulfoxide fiber according to claim 1, characterized in that: The method also includes a cleaning process, wherein the cleaning process includes closing the dye kettle, introducing clean carbon dioxide fluid, and washing out the dye attached to the fiber surface and the dyeing device and pipeline.

4. The waterless dyeing method for polyphenylene sulfoxide fiber according to claim 1, characterized in that: The sampling process is also included. After the cleaning process is completed, when the temperature of the dye kettle, dyeing kettle and dye recovery kettle reaches 25-40°C and the pressure is released to normal pressure, the dyeing kettle is opened to take out the sample.

5. The waterless dyeing method for polyphenylene sulfoxide fiber according to claim 1, characterized in that: The method also includes an inspection process, which is to measure the color fastness to soaping, the dyeing depth K / S value and various fastness properties of the dyed polyphenylsulfone sulfoxide fiber according to national standards.

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