A dyeing auxiliary agent for nylon / spandex composite fibers and its preparation method

Abstract

This invention discloses a dyeing auxiliary agent for nylon / spandex composite fibers and its preparation method, aiming to provide a dyeing auxiliary agent that can significantly improve the problems of "white exposure" and staining of nylon / spandex composite fibers; its structural formula is as follows: where: x = 1~50; y = 1~50; z = 1~10; belonging to the field of applied chemical technology.

Description

Technical Field

[0001] This invention relates to a dyeing auxiliary agent for nylon / spandex composite fibers, and also discloses a method for preparing the auxiliary agent; it belongs to the field of applied chemical technology. Technical Background

[0002] Spandex, also known as polyurethane fiber, is often combined with nylon due to its excellent breathability, elongation, and elastic recovery. It is widely used in yoga wear, swimwear, underwear, and other fields.

[0003] Dyes available for nylon include acid dyes, neutral dyes, and reactive dyes. However, regardless of the type of dye, the uptake on spandex is very limited. Therefore, dyeing nylon-spandex composite fibers presents two major challenges: the "white showing" problem of spandex and the problem of spandex staining. "White showing" refers to the undyed spandex appearing as white undyed spandex when the fiber is stretched, which is particularly noticeable on dark fabrics. This problem significantly lowers the quality of the fabric. Staining of spandex, on the other hand, mostly manifests as poor wash fastness.

[0004] To address the above issues, current research mainly focuses on the following two aspects:

[0005] (1) Modify spandex from the perspective of fiber to make it easier to dye.

[0006] Currently, researchers mainly modify spandex to improve its dyeability by adjusting the polyol / isocyanate or chain extender portion. Chinese patents CN103483478A, CN104141176A, and CN101096779A all describe how to modify spandex to improve its dyeing performance. Overall, the effect is generally average, and its mechanical properties are affected while modifying spandex. Dyeable spandex is also much more expensive than ordinary spandex, increasing the cost pressure on dyeing plants.

[0007] (2) From the perspective of dyes, develop dyes specifically for spandex.

[0008] There are many studies and reports on modified disperse dyes, but almost none on acid dyes. Moreover, the modification of dyes is relatively complex and not widely applicable to fibers. Summary of the Invention

[0009] Therefore, the purpose of this invention is to provide a dyeing auxiliary that can significantly improve the problems of "white showing" and staining in nylon / spandex composite fibers, as well as a method for preparing the auxiliary.

[0010] Therefore, the first technical solution provided by this invention is as follows:

[0011] A dyeing auxiliary agent for nylon / spandex composite fibers, with the following structural formula:

[0012]

[0013] Where: x = 1~50; y = 1~50; z = 1~10.

[0014] The second technical solution provided by this invention is a method for preparing the dyeing auxiliary agent for nylon / spandex composite fibers as described in the first technical solution, comprising the following steps in sequence:

[0015] 1) Add 14.4–21.6 parts of sodium p-hydroxybenzenesulfonate, 6–9 parts of urea, and 108.6–401 parts of intermediate (Ⅰ) sequentially into a four-necked flask;

[0016] 2) Raise the temperature to 60℃ and begin adding 28.4–30 parts of formaldehyde aqueous solution dropwise over 2–4 hours; continue the reaction at 60℃ for 2–3 hours.

[0017] 3) After cooling to room temperature, a brownish-red viscous liquid is obtained, which is the dyeing auxiliary agent for nylon / spandex composite fibers;

[0018] The structural formula of intermediate (Ⅰ) is as follows:

[0019]

[0020] Intermediate (Ⅰ)

[0021] Where: R is -H or -CH3; n = 1 to 100.

[0022] Furthermore, in the above-mentioned method for preparing the dyeing auxiliary agent for nylon / spandex composite fibers, intermediate (Ⅰ) is prepared through the following steps:

[0023] 1) Add 75-150 parts of polyol, 75-150 parts of ethanol, 9.38-18.75 parts of methyl carbamate, and 0.005-0.01 parts of tetrabutyl titanate catalyst to a three-necked flask.

[0024] 2) Heat to boiling point and react for 3 hours. During the reaction, methanol, a byproduct, is released.

[0025] 3) Remove the reaction solvent ethanol by vacuuming;

[0026] 4) Discharge the material to obtain a yellow viscous liquid intermediate (Ⅰ).

[0027] Furthermore, in the above-mentioned method for preparing the dyeing auxiliary agent for nylon / spandex composite fibers, the four-necked flask is equipped with a stirrer, a thermometer, and a nitrogen protection device.

[0028] Furthermore, in the above-mentioned method for preparing the dyeing auxiliary agent for nylon / spandex composite fibers, the three-necked flask is equipped with a stirrer, a thermometer, and a vacuum device.

[0029] Furthermore, in the above-mentioned method for preparing the dyeing auxiliary agent for nylon / spandex composite fibers, the mass concentration of the formaldehyde aqueous solution is 37%.

[0030] Furthermore, in the above-mentioned method for preparing the dyeing auxiliary agent for nylon / spandex composite fibers, the polyol is one of PPG1500, PEG1000, and PEG3000.

[0031] Compared with the prior art, the present invention has the following advantages:

[0032] 1. The nylon / spandex composite fiber dyeing auxiliary agent provided by the present invention has abundant -OH, -NH groups and sulfonic acid groups, which can have a good binding force with acid dyes and can greatly improve the fastness of dyes on fibers.

[0033] 2. The nylon / spandex composite fiber dyeing auxiliary agent provided by the present invention has NH-C(O) bonds that are very similar to those of spandex. According to the principle of like dissolves like, it can improve the adsorption of dye on spandex, effectively avoiding "white exposure" and staining problems caused by poor dye bonding in the later stage.

[0034] 3. The nylon / spandex composite fiber dyeing auxiliary agent provided by the present invention has readily available raw materials and a simple process. Attached Figure Description

[0035] Figure 1 The compound provided in Example 3 of this application 1 H NMR spectrum. Detailed Implementation

[0036] The technical solution of the present invention will be clearly and completely described below. Obviously, the described embodiments are only the main test process of the present invention. For process parameters or conditions not specifically noted, conventional techniques can be referred to.

[0037] Example 1

[0038] This invention provides a dyeing auxiliary agent for nylon / spandex composite fibers, the structural formula of which is as follows:

[0039]

[0040] Where: x=12, y=25, z=5.

[0041] The preparation method of this dyeing auxiliary agent includes the following steps in sequence:

[0042] 1) Add 18g of sodium p-hydroxybenzenesulfonate, 9g of urea and 108.6g of intermediate (Ⅰ) to a 500ml four-necked flask (equipped with a stirrer, thermometer and nitrogen protection device);

[0043] 2) Raise the temperature to 60℃, and when the temperature reaches 60℃, start adding 28.4g of 37% formaldehyde aqueous solution dropwise, and finish adding it over 3 hours;

[0044] 3) Maintain the temperature at 60℃ and continue the reaction for 2 hours;

[0045] 4) Cool to room temperature to obtain a brownish-red viscous liquid. Filter through a 200-mesh sieve to remove possible impurities to obtain the dyeing auxiliary agent for nylon / spandex composite fibers.

[0046] Intermediate (Ⅰ) is prepared by the following steps:

[0047] 1) Add 150g PPG1500, 150g ethanol, 18.75g methyl carbamate, and 0.01g tetrabutyl titanate catalyst sequentially into a 500ml three-necked flask (equipped with a stirrer, thermometer, and vacuum equipment).

[0048] 2) Turn on the heating equipment and heat to boiling point. Time the reaction for 3 hours. During the reaction, methanol, a byproduct, will be removed.

[0049] 3) Turn on the vacuum equipment and evacuate (control the vacuum level below -0.8MPa) to remove the reaction solvent ethanol;

[0050] 4) Discharge the material and filter it through a 200-mesh sieve to obtain a yellow viscous liquid intermediate (Ⅰ).

[0051]

[0052] Intermediate (Ⅰ)

[0053] Where: R = -CH3, n = 25.

[0054] Example 2

[0055] This invention provides a dyeing auxiliary agent for nylon / spandex composite fibers, the structural formula of which is:

[0056]

[0057] Where: x=9, y=20, z=2.

[0058] The preparation method of this dyeing auxiliary agent includes the following steps in sequence:

[0059] 1) Add 14.4g of sodium p-hydroxybenzenesulfonate, 7.2g of urea and 401g of intermediate (Ⅰ) sequentially into a 500ml four-necked flask (equipped with a stirrer, thermometer and nitrogen protection device);

[0060] 2) Raise the temperature to 60℃, and when the temperature reaches 60℃, start adding 28.4g of 37% formaldehyde aqueous solution dropwise, and finish adding it over 3 hours;

[0061] 3) Maintain the temperature at 60℃ and continue the reaction for 3 hours;

[0062] 4) Cool to room temperature to obtain a brownish-red viscous liquid. Filter through a 200-mesh sieve to remove possible impurities to obtain the dyeing auxiliary agent for nylon / spandex composite fibers.

[0063] Intermediate (Ⅰ) is prepared by the following steps:

[0064] 1) Add 150g PEG3000, 150g ethanol, 9.38g methyl carbamate, and 0.005g tetrabutyl titanate catalyst sequentially into a 500ml three-necked flask (equipped with a stirrer, thermometer, and vacuum equipment).

[0065] 2) Heat to boiling point and react for 3 hours. During the reaction, methanol, a byproduct, is released.

[0066] 3) Remove the reaction solvent ethanol by drawing a vacuum (vacuum degree controlled below -0.8MPa);

[0067] 4) Discharge the material and filter it through a 200-mesh sieve to obtain a yellow viscous liquid intermediate (Ⅰ).

[0068]

[0069] (I)

[0070] Where: R = -H, n = 67.

[0071] Example 3

[0072] This invention provides a dyeing auxiliary agent for nylon / spandex composite fibers, the structural formula of which is:

[0073]

[0074] Where: x=15, y=15, z=3.

[0075] The preparation method of this dyeing auxiliary agent includes the following steps in sequence:

[0076] 1) Add 21.6g of sodium p-hydroxybenzenesulfonate, 6g of urea and 238g of the above intermediate (Ⅰ) to a 500ml four-necked flask (equipped with a stirrer, thermometer and nitrogen protection device);

[0077] 2) Raise the temperature to 60℃, and when the temperature reaches 60℃, start adding 30g of 37% formaldehyde solution dropwise, and finish adding it over 3 hours;

[0078] 3) Maintain the temperature at 60℃ and continue the reaction for 2 hours;

[0079] 4) Cool to room temperature to obtain a brownish-red viscous liquid. Filter through a 200-mesh sieve to remove possible impurities to obtain the dyeing auxiliary agent for nylon / spandex composite fibers.

[0080] Intermediate (Ⅰ) is prepared by the following steps:

[0081] 1) Add 50g PEG1000, 50g ethanol, 9.38g methyl carbamate, and 0.005g tetrabutyl titanate catalyst sequentially into a 250ml three-necked flask (equipped with a stirrer, thermometer, and vacuum equipment).

[0082] 2) Heat to boiling point and react for 3 hours. During the reaction, methanol, a byproduct, is released.

[0083] 3) Remove the reaction solvent ethanol by drawing a vacuum (vacuum degree controlled below -0.8MPa);

[0084] 4) Discharge the material and filter it through a 200-mesh sieve to obtain a yellow viscous liquid intermediate (Ⅰ).

[0085]

[0086] (I)

[0087] Where: R = -H, n = 22.

[0088] That 1 See H NMR spectrum Figure 1 ,pass Figure 1 It can be seen that the peak at around 7.8 ppm corresponds to the -OH group on the benzene ring, the peak at 7.3-7.5 ppm corresponds to the hydrogen group on the benzene ring, the peak at 4.7-4.9 ppm corresponds to the urea group NH, and the peak at 2.3-3.3 ppm corresponds to the hydrogen group on the methylene group.

[0089] To better utilize the nylon / spandex composite fiber dyeing auxiliary agent provided in this application, the actual dyeing formula table 1 is given below:

[0090] Table 1

[0091] Components Formula 1 dosage Formula 2 dosage Acid dye (red) (% owf) 2.0 - Acid dye (blue) (% owf) - 2.5 Leveling agent % 2.0 2.0 The dyeing auxiliary agent provided in Example 1% 1.5 1.5 pH value of dye bath 5 5 Bath ratio 1:20 1:20

[0092] It should be noted that the percentage of the leveling agent and the dyeing auxiliary agent provided in Example 1 is the percentage of the mass of the product to be dyed.

[0093] Customers can choose leveling agents according to their actual needs.

[0094] In practical use, place the product to be dyed into the dyeing container, add each component according to the dosage of formula 1 or formula 2, heat to 40℃, stir evenly, then heat to 98℃ again for dyeing for 60 minutes, and then cool to room temperature and wash with water.

[0095] To demonstrate the effectiveness of the technical solution provided in this application, the performance testing process and data of the dyeing auxiliaries provided in Examples 1 to 3 are given below:

[0096] Post-staining performance testing:

[0097] 1. The apparent color gain (K / S) value of nylon / spandex composite fabric (nylon / spandex 80 / 20) after dyeing was tested using an SF600XDatacolor colorimetric spectrometer (D65 light source). Three parallel measurements were taken at different locations on the fabric surface, and the average value was recorded. The results are shown in Table 2.

[0098] Table 2

[0099]

[0100] The blanks mentioned in Table 2 refer to those without the nylon / spandex composite fiber dyeing auxiliaries provided in this application. Other formulations and conditions are the same as in Examples 1-3.

[0101] 2. The color fastness to washing was tested according to the experimental scheme B(2) in GB / T3921—2008 Textiles - Tests for Color Fastness to Washing. The color fastness and staining fastness of the fabric were tested. The lining fabrics were acetate, cotton, nylon, polyester, acrylic and wool. The results are shown in Table 3:

[0102] Table 3

[0103]

[0104] The blanks mentioned in Table 3 refer to dyeing auxiliaries for nylon / spandex composite fibers that do not contain the dyeing agent provided in this application. Other formulations and conditions are the same as in Examples 1-3.

[0105] As can be seen from Table 2, when using acid dyes to dye spandex fabrics in the same bath, compared with the blank, the addition of the dyeing auxiliary in the examples can significantly increase the K / S value of nylon / spandex blended fabrics. Moreover, after soaping, the K / S value of the fibers treated with the dyeing auxiliary in the examples is still much higher than that of the untreated blank sample. This indicates that the dyeing auxiliary in this invention can effectively help the acid dyes to be dyed onto spandex and penetrate into the fiber interior. Furthermore, after soaping, a significant amount of dye remains on the fiber, indicating that the acid dyes and spandex have a good bond.

[0106] As can be seen from Table 3, compared with the blank sample, the nylon / spandex blended fabric with the dyeing auxiliary added in the examples has excellent washing fastness, especially it can improve the staining grade of dye on nylon and wool, indicating that the dyeing auxiliary can help improve the binding force of acid dyes with nylon and spandex fabrics.

Claims

1. A method for preparing a dyeing auxiliary agent for nylon / spandex composite fibers, characterized in that, The steps are as follows: 1) Add 14.4–21.6 parts of sodium p-hydroxybenzenesulfonate, 6–9 parts of urea, and 108.6–401 parts of intermediate (Ⅰ) sequentially into a four-necked flask; 2) Raise the temperature to 60℃ and begin adding 28.4–30 parts of formaldehyde aqueous solution dropwise over 2–4 hours; continue the reaction at 60℃ for 2–3 hours. 3) After cooling to room temperature, a brownish-red viscous liquid is obtained, which is the dyeing auxiliary agent for nylon / spandex composite fibers; The structural formula of intermediate (Ⅰ) is as follows: ； (Ⅰ) Where: R is -H or -CH3; n = 22 to 100.

2. The method for preparing the dyeing auxiliary agent for nylon / spandex composite fibers according to claim 1, characterized in that, Intermediate (Ⅰ) is prepared by the following steps: 1) Add 75-150 parts of polyol, 75-150 parts of ethanol, 9.38-18.75 parts of methyl carbamate, and 0.005-0.01 parts of tetrabutyl titanate catalyst to a three-necked flask. 2) Heat to boiling point and react for 3 hours. During the reaction, methanol, a byproduct, is released. 3) Remove the reaction solvent ethanol by vacuuming; 4) Discharge the material to obtain a yellow viscous liquid intermediate (Ⅰ).

3. The method for preparing the dyeing auxiliary agent for nylon / spandex composite fibers according to claim 2, characterized in that, The four-necked flask is equipped with a stirrer, a thermometer, and a nitrogen protection device.

4. The method for preparing the dyeing auxiliary agent for nylon / spandex composite fibers according to claim 2, characterized in that, The three-necked flask is equipped with a stirrer, a thermometer, and a vacuum device.

5. The method for preparing the dyeing auxiliary agent for nylon / spandex composite fibers according to claim 2, characterized in that, The mass concentration of the formaldehyde aqueous solution is 37%.

6. The method for preparing the dyeing auxiliary agent for nylon / spandex composite fibers according to claim 2, characterized in that, The polyol is one of PPG1500, PEG1000, and PEG3000.

7. A dyeing auxiliary agent for nylon / spandex composite fibers, characterized in that, Prepared using the method described in any one of claims 1-6.

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