A method for improving the dye fastness of polyphenylene sulfide fibers

Abstract

The present application relates to a kind of method for improving the dyeing fastness of polyphenyl sulfide fiber, comprising the following steps: 1, phosphate starch, defoaming agent, ethylene glycol phenyl ether and fatty alcohol polyoxyethylene ether sodium sulfate are mixed, stirring and heating to 95 DEG C or more, preparation obtains dyeing liquid;2, in dyeing liquid, polyphenyl sulfide fiber, sodium chloride and glacial acetic acid are then put into dyeing machine and dyeing, washing and drying after obtaining dyed polyphenyl sulfide fiber.The esterification degree of 2-3 phosphate starch used in the present application has good affinity to hydrophobic polyphenyl sulfide fiber, and under high temperature dyeing conditions, the vat dye soluble in ethylene glycol phenyl ether is more easily combined with fiber, enters the inside of fiber, improves dyeing effect, realizes the dyeing depth of excellent vat dye dyeing polyphenyl sulfide fiber, and then reaches the effect of high color depth and high light fastness of vat dye dyeing polyphenyl sulfide fiber.

Description

Technical Field

[0001] This invention belongs to the field of fiber dyeing, and in particular, it is a method for improving the color fastness of polyphenylene sulfide fibers. Background Technology

[0002] Although disperse dyes can achieve high color depth with the help of a carrier, the light fastness of conventional disperse dyes is only grade 1-2, and even disperse dyes with good light fastness only reach grade 3-4, making it difficult to achieve good results and thus limiting their application.

[0003] Poor lightfastness is a bottleneck problem in the application of polyphenylene sulfide (PPS). This problem is caused by the conjugation of benzene rings and sulfur atoms on the main chain of PPS molecules, and the fact that the sulfur atoms are not yet saturated. After absorbing ultraviolet light energy, the color changes, resulting in low lightfastness and loss of strength.

[0004] Vat dyes are numerous, have a complete color spectrum, and offer vibrant colors, along with excellent lightfastness. However, when used to dye polyphenylene sulfide fibers, their dyeing rate is low, making it impossible to achieve high lightfastness for certain varieties. Furthermore, the limitation in color depth restricts their further applications.

[0005] Therefore, in order to solve the problem that vat dyes are not easy to bind with polyphenylene sulfide fibers, resulting in difficulty in dyeing and poor light fastness, we utilize the high affinity of phosphate ester amylase and fatty alcohol polyoxyethylene ether sulfate for hydrophobic polyphenylene sulfide fibers, as well as the effective adsorption of phosphate ester starch on the carrier, to make it easier for vat dyes to be adsorbed on the fiber surface and penetrate into the fiber interior, thereby achieving a dyeing effect and solving the problem that vat dyes are difficult to dye polyphenylene sulfide fibers, resulting in poor light fastness. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a method for improving the color fastness of polyphenylene sulfide fibers.

[0007] A method for improving the color fastness of polyphenylene sulfide fibers includes the following steps:

[0008] Step 1: Mix phosphate starch with an esterification degree of 2-3, defoamer, ethylene glycol phenyl ether and sodium fatty alcohol polyoxyethylene ether sulfate, stir and heat to above 95°C to prepare the dyeing solution.

[0009] Step 2: Add dye, polyphenylene sulfide fiber, sodium chloride and glacial acetic acid to the dyeing solution from the previous step. Then put it into the dyeing machine, raise the temperature to 120-140℃ and keep it at that temperature for 55-65 minutes. After cooling to 75-85℃, take it out, add amylase and keep it at that temperature for more than 5 minutes.

[0010] Step 3: After the heat preservation is completed, the fiber is removed after cooling to 70℃, washed and dried to obtain dyed polyphenylene sulfide fiber.

[0011] Furthermore, the content of the phosphate starch is 0.5 g / L-1.5 g / L.

[0012] Furthermore, the content of ethylene glycol phenyl ether in step 1 is 20-40 g / L.

[0013] Furthermore, the content of sodium fatty alcohol polyoxyethylene ether sulfate in step 1 is 0.5 g / L-1.5 g / L.

[0014] The beneficial effects of this invention are as follows: The phosphate starch with an esterification degree of 2-3 used in this invention has good affinity for hydrophobic polyphenylene sulfide (PPS) fibers and can effectively aggregate and adsorb onto the surface of PPS fibers. Sodium fatty alcohol polyoxyethylene ether sulfate (SOLS) is a surfactant that can adsorb both lipophilically and hydrophilically, while also exhibiting excellent diffusivity. It also has a high affinity for phosphate starch and, under low-speed stirring, combines with phosphate starch, thus improving the adsorption of phosphate starch onto PPS fibers. Furthermore, phosphate starch has a good spatial branched structure. Although the viscosity increases after esterification, a small amount of phosphate starch enzyme can be miscible with the ethylene glycol phenyl ether carrier. High-speed stirring at 95°C helps to achieve high aggregation of ethylene glycol phenyl ether, i.e., combining with phosphate starch, allowing it to efficiently aggregate on the fiber surface. Thus, under high-temperature dyeing conditions, vat dyes soluble in ethylene glycol phenyl ether can more easily combine with fibers, penetrate into the fiber interior, improve the dyeing effect, achieve excellent dyeing depth of vat dyes on polyphenylene sulfide fibers, and thus achieve the effect of high color depth and high light fastness of vat dyes on polyphenylene sulfide fibers. Detailed Implementation

[0015] The technical solution of the present invention will be clearly and completely described below. Obviously, the described embodiments are partial embodiments of the present invention, not the entire embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0016] The method for improving the color fastness of polyphenylene sulfide fibers provided by the present invention will be described below with reference to specific embodiments and comparative examples:

[0017] Example 1 Process:

[0018] 1. First, add 0.5 g / L of phosphate starch with an esterification degree of 2 and 0.5 g / L of sodium fatty alcohol polyoxyethylene ether sulfate. Add 0.5 g / L of defoamer at room temperature. Stir for 5 min at a speed of 400 r / min. Then, heat to 95℃ and stir at a speed of 800 r / min. At the same time, add 20 g / L of carrier (ethylene glycol phenyl ether) and stir for 10 min.

[0019] 2. Add the prepared dye solution to the dyeing accelerator in step 1, stir well, and then pour into the dyeing cup;

[0020] 3. Add cellulose, 20 g / L sodium chloride (liquid ratio 1:20), and glacial acetic acid (pH: 3-4) to the solution prepared in step 2. Then place it in a dyeing machine and heat it to 130°C at a rate of 1°C / min and keep it at that temperature for 60 min. Then start cooling it down at a rate of 2°C / min. When the temperature drops to 80°C, take it out, add amylase, and keep it at that temperature for 5 min.

[0021] 4. After the heat preservation in step 3 is completed, start cooling down at 2℃ / min to below 70℃. Remove the fibers and wash them with water. After washing, perform soap washing with a bath ratio of 1:20, adding 3g / L of sodium carbonate and 2g / L of soap powder. Raise the temperature to 90℃ at a rate of 2℃ / min and keep it at that temperature for 20min. Then start cooling down at 2℃ / min to below 70℃. Remove the fibers and wash them with water. After washing, dry them.

[0022] Process of Examples 2-3:

[0023] First, add phosphate starch, sodium fatty alcohol polyoxyethylene ether sulfate, defoamer, and ethylene glycol phenyl ether as required in step 1; then proceed with steps 2-3 in sequence. The difference between Examples 2-3 and Example 1 is that Example 2 adds 30 g / L ethylene glycol phenyl ether; Example 3 adds 40 g / L ethylene glycol phenyl ether.

[0024] Example 4 Process:

[0025] The operation steps are the same as in Example 1, but Example 4 is characterized by the addition of phosphate starch with an esterification degree of 3 in Example 4.

[0026] Example 5 Process:

[0027] The operation steps are the same as in Example 2, but Example 5 is characterized by the addition of phosphate starch with an esterification degree of 3 in Example 5.

[0028] Example 6 Process:

[0029] The operation steps are the same as in Example 3, but Example 6 is characterized by the addition of phosphate starch with an esterification degree of 3 in Example 6.

[0030] Comparative Example 1 Process:

[0031] The operation steps are the same as in Example 1, but the feature of Comparative Example 1 compared to Example 1 is that: Comparative Example 1 adds phosphate starch with a degree of esterification of 1.

[0032] Comparative Example 2 Process:

[0033] The operation steps are the same as in Example 2, but the feature of Comparative Example 2 is that: Comparative Example 2 adds phosphate starch with an esterification degree of 1.

[0034] Comparative Example 3 Process:

[0035] The operation steps are the same as in Example 3, but the feature of Comparative Example 3 compared to Example 3 is that: Comparative Example 3 adds phosphate starch with an esterification degree of 1.

[0036] Comparative Example 4 Process:

[0037] 1. After stirring the prepared dye solution evenly, pour it into the dye cup;

[0038] 2. Add polyphenylene sulfide fiber, sodium chloride 20g / L (liquor ratio 1:20), glacial acetic acid (pH: 3-4), and ethylene glycol phenyl ether 20g / L to the dyeing solution prepared in step 1. Then place it in the dyeing machine and raise the temperature to 130℃ at a rate of 1℃ / min and keep it at that temperature for 60min. Then lower the temperature to below 70℃ at a rate of 2℃ / min. Remove the fiber and wash it with water.

[0039] 3. After washing with water, perform soap washing. The soap washing is carried out at a bath ratio of 1:20, with the addition of 3g / L sodium carbonate and 2g / L soap powder. The temperature is raised to 90℃ at a rate of 2℃ / min and held for 20min. Then, the temperature is lowered to below 70℃ at a rate of 2℃ / min. After removing the fibers, they are washed with water and then dried.

[0040] Comparative Example 5-6 process:

[0041] The operation steps are the same as those of Comparative Example 4. The difference between Comparative Examples 5 and 6 and Comparative Example 4 is that Comparative Example 5 adds 30 g / L ethylene glycol phenyl ether; and Comparative Example 6 adds 40 g / L ethylene glycol phenyl ether.

[0042] Comparative Example 7 Process:

[0043] The operation steps are the same as those of Comparative Example 4, but Comparative Example 7 is characterized by the fact that ethylene glycol phenyl ether is not added to Comparative Example 7.

[0044] The examples and comparative data are as follows, using Vat Blue BO as the dye:

[0045] The technical effects are mainly reflected in color depth and the corresponding light fastness index.

[0046]

[0047] The data above show that: dyeing according to the methods of Examples 1-3 significantly improves the color depth and lightfastness of the polyphenylene sulfide (PPS) fiber samples, with Example 3 exhibiting the best color depth and lightfastness; dyeing according to the methods of Examples 4-6 slightly improves the color depth of the PPS fiber samples with increasing esterification degree of phosphate starch, but shows no significant difference in lightfastness, indicating that the higher the esterification degree of phosphate starch, the better its water solubility and the stronger its interaction with sodium fatty alcohol polyoxyethylene ether sulfate and ethylene glycol phenyl ether; dyeing according to the methods of Comparative Examples 1-3 significantly reduces the color depth and lightfastness of the PPS fiber samples with decreasing esterification degree of phosphate starch, indicating that the interaction between phosphate starch and sodium fatty alcohol polyoxyethylene ether sulfate and ethylene glycol phenyl ether is significant when the esterification degree is 2-3, which is beneficial to the dyeing of PPS fiber, while the improvement in dyeing effect is not significant when the esterification degree is low. Following the dyeing methods of Comparative Examples 4-7, the color depth and lightfastness of the polyphenylene sulfide fiber samples gradually increased with the increase of ethylene glycol phenyl ether. Furthermore, through a relative comparison of the dyeing performance between the examples and the comparative examples (Example 1 / 4 vs. Comparative Example 4; Example 2 / 5 vs. Comparative Example 5; Example 3 / 6 vs. Comparative Example 6), the addition of phosphate starch with an esterification degree of 2-3 and sodium fatty alcohol polyoxyethylene ether sulfate again significantly improved the color depth and lightfastness. This indicates that there is a synergistic effect between the phosphate starch with an esterification degree of 2-3 and sodium fatty alcohol polyoxyethylene ether sulfate, and under the same dyeing process conditions and carrier, an increase in the proportion of phosphate starch and sodium fatty alcohol polyoxyethylene ether sulfate is beneficial for improving color depth and lightfastness.

[0048] 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 within the protection scope of the present invention.

Claims

1. A method for improving the color fastness of polyphenylene sulfide fibers, characterized in that: Includes the following steps: Step 1: Mix phosphate starch with a degree of esterification of 2-3, defoamer, ethylene glycol phenyl ether, and sodium fatty alcohol polyoxyethylene ether sulfate, stir and heat to above 95°C to prepare a dyeing accelerator; the content of phosphate starch is 0.5 g / L-1.5 g / L, and the content of ethylene glycol phenyl ether in Step 1 is 20-40 g / L; Step 2: Add dye, polyphenylene sulfide fiber, sodium chloride and glacial acetic acid to the dyeing solution from the previous step. Then put it into the dyeing machine, raise the temperature to 120-140℃ and keep it at that temperature for 55-65 minutes. After cooling to 75-85℃, take it out, add amylase and keep it at that temperature for more than 5 minutes. Step 3: After the heat preservation is completed, the fiber is removed after cooling to 70℃, washed, and then dried to obtain dyed polyphenylene sulfide fiber.

2. The method for improving the color fastness of polyphenylene sulfide fibers according to claim 1, characterized in that: In step 1, the content of sodium fatty alcohol polyoxyethylene ether sulfate is 0.5 g / L-1.5 g / L.

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