A method for increasing the color depth of polyarylate fiber dyeing

Abstract

The present invention relates to a method for improving the color depth of polyarylate fiber dyeing. The method mainly involves modifying the polyarylate fiber with sodium carbonate, urea, and a coupling agent solution and then dyeing with a carrier. The present invention increases the surface activity and roughness of the polyarylate fiber by sodium carbonate and urea, and connects them together on the fiber surface through a silane coupling agent KH570 to form a network structure that wraps the fiber. The ethylene glycol phenyl ether used in dyeing is oily and organically integrates with the KH570 layer on the fiber surface, making it easier to carry dye into the fiber and improving the dyeing efficiency of the ethylene glycol phenyl ether carrier. Since the surface activity of the polyarylate fiber is improved, the adsorption capacity of the aqueous dye solution is enhanced, thereby improving the dyeing effect. The polyarylate fiber after the modified dyeing treatment of the present invention has a K / S value of up to 8.65, and the color depth is increased by 13.3 times; and the color remains substantially unchanged after 40 hours of sun exposure.

Description

Technical Field

[0001] The invention belongs to the field of fiber dyeing, in particular to a method for improving the dyeing depth of polyarylate fibers. Background Art

[0002] Polyarylate fiber is a high-tech fiber with excellent overall properties, including high strength and modulus, high-temperature resistance, self-flammability, chemical and radiation resistance, and strong dimensional stability. Its overall mechanical properties are slightly higher than those of aramid fiber, and its hydrophobicity makes it widely used in aerospace, military, and sports applications. Furthermore, compared to the three traditional high-performance fibers (aramid, ultra-high molecular weight polyethylene, and carbon fiber), it is the only high-performance fiber produced using the melt spinning method, resulting in lower costs and less pollution.

[0003] Polyarylate molecular chains have high rigidity and a long relaxation time, and their highly oriented structure is almost completely retained after cooling and solidification. Therefore, during the melt spinning process, the polyarylate melt can achieve a high degree of orientation when passing through the spinneret, even at low shear rates, resulting in high mechanical properties of the fiber. However, thermotropic liquid crystal polyarylate fibers do not have active groups and have extremely low surface energy, resulting in poor adhesion to the fiber surface and poor dyeing properties.

[0004] Currently, only solution coloring technology can color thermotropic liquid crystal polyarylate fibers. However, fibers produced using this technology exhibit poor interaction between the masterbatch and the fibers, resulting in reduced interfiber cohesion, which in turn reduces mechanical properties, resulting in low strength retention and a limited variety of colors. Furthermore, the spinning solution is less stable during the production process, and spinnerets are prone to clogging, limiting the further industrial application of thermotropic liquid crystal polyarylate fibers.

[0005] Patent application number CN110184669A discloses a colored polyarylate fiber and its preparation method. First, an organic pigment is added to a dispersion medium containing a stabilizer and mixed uniformly to produce a colored slurry. The colored slurry is then introduced into molten polyarylate, and finally, the mixture is mixed, filtered, and spun to produce the colored polyarylate fiber. The mechanical properties of the fiber produced by this method are significantly reduced, and the equipment is prone to wear and tear. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a method for increasing the dyeing depth of polyarylate fibers.

[0007] A method for increasing the color depth of polyarylate fiber dyeing, comprising the following steps:

[0008] Step 1, washing and drying the polyarylate fiber;

[0009] Step 2: Mixing sodium carbonate, urea and coupling agent KH570 to prepare a modified solution;

[0010] Step 3: Modifying the polyarylate fiber using a modification solution to obtain modified polyarylate fiber;

[0011] Step 4: dyeing the modified polyarylate fiber.

[0012] Furthermore, in the modified solution of step 2, the content of sodium carbonate is 5 g / L-30 g / L, and the mass fraction of the silane coupling agent KH570 is 1%.

[0013] Furthermore, the specific content of step 3 is:

[0014] The polyarylate fiber treated in step 1 was added to the modified solution at a bath ratio of (1-2):30, and the solution was kept at 130° C. for 60 min. The modified polyarylate fiber was then washed and dried to obtain the modified polyarylate fiber.

[0015] Furthermore, the dye solution in step 4 includes 35-45 g / L of ethylene glycol phenyl ether.

[0016] Furthermore, in the modified solution of step 2, the content of urea is 10 g / L-15 g / L.

[0017] The beneficial effects of the present invention are:

[0018] Polyarylate is not alkali-resistant. When sodium carbonate and urea are dissolved in water, urea will react with CO3 2- Ion fusion, achieving Na + The sustained-release effect of KH570, at a temperature of 130°C, breaks the macromolecular chains on the surface of polyarylate fibers, generating new functional groups. KH570 partially hydrolyzes under alkaline conditions to produce highly reactive -OH groups, which react and connect with the new end groups on the polyarylate fiber macromolecular chains. KH570 is oily, and after grafting onto the fiber surface, it hinders the interaction of sodium carbonate and urea in the aqueous solution with the fibers, forming a protective layer and further modifying the fiber surface.

[0019] As a result, the surface activity of the polyarylate fiber increases, and KH570 forms a network of reactive bonds on the fiber surface, effectively enveloping the fiber. The oily ethylene glycol phenyl ether used in dyeing organically blends with the KH570 layer on the fiber surface. The KH570 layer helps the ethylene glycol phenyl ether carry the dye into the fiber, improving dyeing efficiency.

[0020] As the surface activity of polyarylate fibers increases, their adsorption capacity for aqueous dye solutions is enhanced, further improving the dyeing effect.

[0021] The method of the present invention does not involve changes in the fiber crystallization area, but is a surface treatment of the fiber. The dyeing color depth can be increased by 13.3 times, the mechanical retention rate reaches 97.56%, and the thermal properties are almost unchanged.

[0022] Experiments have shown that the color of the polyarylate fiber treated with the modified dyeing method of the present invention remains essentially unchanged after being exposed to the sun for 40 hours, and the diversified colors of the dyed polyarylate fiber can be applied in multiple fields, thus expanding its application. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 Schematic diagram of the modification process of the present invention;

[0024] Figure 2 Schematic diagram of the dyeing process of the present invention. DETAILED DESCRIPTION

[0025] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiment described is a sub-embodiment of the present invention, not a complete embodiment. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0026] Example 1

[0027] like Figure 1-2 As shown, a method for increasing the color depth of polyarylate fiber dyeing is to modify the polyarylate fiber by bathing it with sodium carbonate, urea, and a coupling agent solution and then dye it with a carrier. The specific steps are as follows:

[0028] The polyarylate fiber was first cleaned in a 5g / L JFC pretreatment bath to remove surface impurities, and then dried at 60°C. A mixed solution of 10g / L sodium carbonate, 10g / L urea, and 1% silane coupling agent KH570 was prepared. The polyarylate fiber was placed in the treatment bath at a bath ratio of 1:30 for 60 minutes, washed to remove unreacted KH570, and dried at 60°C for 20 minutes. A 3% owf Red AM-SLR dye bath was prepared, containing 40g / L ethylene glycol phenyl ether as the carrier, 20g / L NaCl, and HAc adjusted to a pH of 4-5. The modified polyarylate fiber was immersed in the dye bath at a bath ratio of 1:20, dyed at 130°C for 60 minutes, and then washed to remove floating color. The fiber was then dried at 60°C to obtain the modified and dyed polyarylate fiber.

[0029] Examples 2-3

[0030] Examples 2 to 3 respectively provide a modification method for increasing the dyeing depth of polyarylate. Compared with Example 1, the difference lies in adjusting the sodium carbonate concentration and urea concentration. The corresponding parameter values ​​of each example are shown in Table 1.

[0031] Table 1 Modification process parameters provided by Examples 2 to 3

[0032] Modification process Example 2 Example 3 Sodium carbonate concentration (g / L) 5 30 Urea concentration (g / L) 10 15 KH570 concentration (%) 1 1

[0033] Comparative Example 1

[0034] Comparative Example 1 is a traditional high temperature and high pressure dyeing method. Compared with Example 1, the difference is that no modification treatment is performed. The corresponding parameter values ​​are shown in Table 2.

[0035] Table 2 Dyeing process parameters provided by Comparative Example 1

[0036]

[0037]

[0038] The color K / S value, single fiber strength, K / S value after 40 hours of sun exposure, and thermal properties of the polyarylate fibers dyed in the above examples and comparative examples were measured. The results are shown in Table 3:

[0039] Table 3 Color characteristic values ​​of polyarylate fibers

[0040]

[0041] As shown in Table 1, the K / S value of the polyarylate fiber (Comparative Example 1) dyed with the conventional dyeing method showed little change, only 0.65, indicating that conventional high-temperature and high-pressure dyeing methods have difficulty in dyeing the fiber. The K / S value of the polyarylate fiber dyed with this method, synergistically with the carrier, was increased to a maximum of 8.65, a 13.3-fold increase, resulting in an excellent color depth. The color of the polyarylate fiber dyed with this method remained virtually unchanged after 40 hours of sun exposure.

[0042] The single fiber strength test was performed using an INSTRON universal strength tester, and the single fiber strength of the yarn was measured to have no significant change. The strength retention rate of Example 3 can reach 97.56%, and the thermal properties are stable.

[0043] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for increasing the color depth of polyarylate fiber dyeing, characterized in that: The following steps are involved: Step 1, washing and drying the polyarylate fiber; Step 2: Mixing sodium carbonate, urea and coupling agent KH570 to prepare a modified solution; Step 3: Modifying the polyarylate fiber using a modification solution to obtain modified polyarylate fiber; Step 4: dyeing the modified polyarylate fiber; the dye solution in step 4 includes 35-45 g / L of ethylene glycol phenyl ether.

2. The method for increasing the color depth of polyarylate fiber according to claim 1, characterized in that: In the modified solution of step 2, the content of sodium carbonate is 5 g / L-30 g / L, and the mass fraction of the silane coupling agent KH570 is 1%.

3. The method for increasing the color depth of polyarylate fiber according to claim 1, characterized in that: The specific content of step 3 is: The polyarylate fiber treated in step 1 was added to the modified solution at a bath ratio of (1-2):30, and the solution was kept at 130° C. for 60 min. The modified polyarylate fiber was obtained after washing and drying.

4. The method for increasing the color depth of polyarylate fiber dyeing according to claim 1, characterized in that: In the modified solution of step 2, the content of urea is 10 g / L-15 g / L.

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