Dyeing method for improving color fastness of spandex by utilizing azo disperse orange dye

Abstract

The invention discloses a dyeing method for improving color fastness of spandex by utilizing azo disperse orange dye, and belongs to the technical field of textile printing and dyeing. The invention provides a dyeing method capable of improving the color fastness of spandex, and particularly provides an azo disperse orange dye which can be used for dyeing the spandex in a wide range of pH (Potential of Hydrogen) of 4-12 and is high in dye uptake and good in color fastness by applying the azo disperse orange dye with a specific structure to the dyeing of the spandex, so that the color fastness of the dyed spandex is improved.

Description

Technical Field

[0001] This invention belongs to the field of textile printing and dyeing technology, specifically relating to a dyeing method for improving the color fastness of spandex using azo disperse orange dyes. Background Technology

[0002] Spandex fiber, scientifically known as polyurethane fiber, is a synthetic fiber with extremely high elasticity. Its elongation at break can reach 500% to 700%, and it can quickly return to its original shape. This unique property makes spandex widely used in many fields such as clothing (e.g., sportswear, yoga wear, underwear), medical compression clothing, and home furnishings, significantly improving the comfort and fit of fabrics. The molecular structure of spandex consists of soft and hard segments, forming a microphase separation structure, which is the source of its high elasticity.

[0003] Despite its wide range of applications, spandex's inherent molecular structure and chemical properties pose significant challenges to dyeing processes. Poor dyeing performance and low color fastness have become bottlenecks restricting its application in high-end fabrics. Specifically, its technical difficulties manifest in many aspects, such as molecular structure defects, "white showing" phenomenon, poor wet heat fastness, poor washing fastness, and low light fastness.

[0004] To improve the dyeing performance of spandex, the industry has explored various approaches, but all of them have limitations to varying degrees. The approaches can be roughly classified as follows: (1) Fiber modification, introducing groups that can bind dyes (such as amino groups) during the spinning process, so that spandex can be used with acid dyes, etc., but the process is complex, costly, and may damage the elasticity of the fiber. (2) Developing or screening disperse dyes or weak acid dyes suitable for spandex, but according to market feedback, the improvement effect is limited, disperse dyes have poor fastness; although weak acid dyes have better fastness, the deep dyeing ability is still insufficient due to the limited number of amino groups in spandex itself. (3) Using spandex coloring agents, the auxiliary molecules are combined with the fiber to increase the "dyeing seat", the effect and environmental friendliness of the auxiliary agents are different, and the addition may affect the hand feel of the fabric or increase the burden of wastewater treatment. (4) Optimizing the dyeing process, such as alkali reduction treatment to etch the fiber surface to facilitate the adhesion of auxiliary agents; or using cold pad-batch dyeing to save energy. However, alkali reduction treatment requires precise control, otherwise it can easily damage the fiber; the application process parameters of cold pad-batch dyeing on spandex are still not fully explored, and the improvement in fastness is limited.

[0005] Currently, disperse dyes suitable for spandex have been developed or screened and have become mainstream, such as the monoazo disperse dyes such as Disperse Yellow H4GL, Disperse Yellow Brown 2RFL, Disperse Ruby S-2GFL, and Disperse Scarlet SBWF launched by Zhejiang Runtu Co., Ltd. ; Zhejiang Longsheng Group Co., Ltd. has launched RGFL, a dispersible yellow diazo disperse dye. ; In addition, Jiangsu Changzhou Yabang Dyestuff Co., Ltd. offers anthraquinone disperse dyes such as Disperse Red 3B and Disperse Turquoise Blue GL. .

[0006] Among the aforementioned dyes, Disperse Ruby S-2GFL showed the best affinity for spandex, achieving a dyeing rate of 91.3%. However, its wet fastness was found to be poor. The dyeing rates of the other dyes were generally between 80% and 85%, with Disperse Turquoise GL even showing a rate of only 50%. The main reason for this is that the soft segments (ether / ester chains) of spandex are porous, allowing dyes to easily enter and exit, while the hard segments have high crystallinity, making it difficult for dyes to bind. Therefore, the binding force between the dyes and spandex is weak, primarily relying on physical adsorption. Even Disperse Ruby S-2GFL, which exhibits good binding affinity to spandex, binds through van der Waals forces and hydrogen bonds, making it easy to detach from the fiber in humid and hot environments.

[0007] Furthermore, the aforementioned dyes are not suitable for dyeing processes with a wide pH range, only applicable within a pH range of 4-7. The ester and cyano groups in most dyes hydrolyze and fade at higher pH conditions, making it impossible to achieve the typical "washing, scouring, and dyeing" or "alkali reduction / dyeing" one-bath process—a practice driven by technological innovation for industrial upgrading. Only alkali-resistant dyes can directly address the core demands of the current printing and dyeing industry for green, efficient, and high-quality development. In short, with the increasing demand for elastic fabrics, the problems facing spandex dyeing are becoming increasingly prominent. Existing technologies have not yet effectively solved the dyeing challenges of spandex, especially under high color fastness requirements, and must also comply with national environmental protection policies for the printing and dyeing industry.

[0008] Based on the above, finding a type of disperse dye that can dye spandex under a relatively wide pH range, with high dyeing rate and good color fastness is a technical problem that urgently needs to be solved. Summary of the Invention

[0009] [Technical Issues] With the increasing use of polyester-spandex blended fibers, the problem of spandex dyeing has become more and more prominent, mainly in the following aspects: (1) Low dyeing rate. Currently, the azo disperse dyes on the market generally have a low dyeing rate. Even if there are azo disperse dyes with a dyeing rate of over 90%, their wet fastness is poor, which causes the dye to migrate from the spandex and stain the polyester.

[0010] (2) Poor color fastness. Due to the special microphase structure of spandex, the fastness of azo disperse dyes is poor.

[0011] (3) Currently, the dyes required for spandex on the market must be dyed under acidic conditions. Combined with reduction cleaning, this results in a long dyeing process, high energy consumption, and a significant increase in environmental pressure.

[0012] [Technical Solution] To address the above shortcomings, this invention provides a dyeing method that can improve the color fastness of spandex. Specifically, it proposes to apply azo disperse orange dye with a specific structure to spandex dyeing. This azo disperse orange dye can dye spandex in a wide pH range of 4 to 12, and has a high dyeing rate and good color fastness, thereby improving the color fastness of spandex dyeing.

[0013] Based on the microphase structure of spandex, the applicant discovered that most disperse dyes on the market, when used for dyeing spandex, result in poor color fastness because the dye molecules have no binding force with the soft segments of spandex, allowing them to easily enter and exit, while the hard segments are crystalline regions where dyes have difficulty entering. However, by modifying and optimizing the molecular structure of azo dyes—specifically by expanding the conjugated system of azo disperse dyes and introducing a benzene ring or benzene ring derivative structure onto one of the N atoms in the N,N-substituent—the polarity and rigidity of the entire dye structure can be ensured. This increases the hydrophobicity and binding force within the soft segment structure of spandex, and due to the increased volume, it makes migration difficult, thereby guaranteeing enhanced color fastness in spandex dyeing.

[0014] Furthermore, the introduction of N,N-substituents into the benzene ring or benzene ring derivatives increases the volume several times, or even tens of times. This creates a significant steric hindrance effect on easily hydrolyzed groups such as ester, cyano, acyl, and ether groups on adjacent N-substituents, preventing the hydrolysis of these groups under alkaline conditions. Therefore, this greatly expands the pH range for spandex dyeing, allowing it to be completed under alkaline conditions. Ultimately, this achieves a typical example of industrial upgrading driven by technological innovation: a one-bath process of "washing, scouring, and dyeing" or a one-bath process of "alkali reduction / dyeing." This fully aligns with the national core requirements for green, efficient, and high-quality development in the environmental protection industry. To achieve the above objectives, the present invention provides the following technical solutions.

[0015] A dyeing method for improving the color fastness of spandex using azo disperse orange dyes, wherein the structure of the azo disperse orange dye is shown in Formula I: Formula I, Where R1 is -H, -Cl, -Br; R2 is -H, -Cl, -Br; R3 is -H, -CH3, -NHSO2CH3; R4 is -H, -CH3, -CH2CH3, -CH2CH2CN, -COCH2COCH3; R5 is -H, -CH3, -CH2CH3, -Cl; R6 is -H, -CH3, -Cl, -NO2; and n is 0, 1, or 2.

[0016] The disperse orange dye compound used in this invention is a monoazo dye with an N-substituent in the coupling component being a benzene ring or a benzene ring derivative. This design aims to increase the conjugation system and hydrophobicity of the molecular structure, as well as increase the rigidity of the molecular structure, thereby increasing the binding force between the dye molecule and the spandex.

[0017] In one embodiment of the present invention, the azo disperse orange dye preferably has the structure of dye 1 to dye 8:

[0018] In one embodiment of the present invention, the azo disperse orange dye is prepared by the following method:

[0019] Step 1: Synthesize compound I-4 Compound I-2 and compound I-3 were condensed together to obtain compound I-4.

[0020] Step 2: Diazotization of Formula I-1 The compound of formula I-1 was dissolved in 93% sulfuric acid and cooled to a certain temperature. Then, 40% nitrosyl sulfuric acid was added dropwise. After the addition was completed, the mixture was kept at the temperature for a certain period of time to carry out the diazotization reaction and obtain a diazo solution.

[0021] Step 3: Synthesize Compound I A measured amount of water and 93% sulfuric acid were added to a four-necked flask, along with compound I-4, aminosulfonic acid, and auxiliary agent O-25. The mixture was stirred and cooled to a certain temperature. Diazo solution was then added dropwise. After the addition was complete, the mixture was kept at the same temperature for several hours. The temperature was then raised to a certain level and maintained for a period of time. The mixture was then hot-filtered and washed with hot water to obtain the target dye with the structure shown in Formula I.

[0022] In one embodiment of the present invention, in step 1, the condensation reaction is carried out in a solvent, which is any one or more mixtures of water, acetone, and acetonitrile; the mass of the solvent is 1.5 to 2.5 times the total mass of compounds of formula I-2 and formula I-3.

[0023] In one embodiment of the present invention, in step 1, the molar ratio of compound I-2 and compound I-3 in the reaction is 1:1.05~1.2.

[0024] In one embodiment of the present invention, in step 1, the acid-binding agent used in the reaction is sodium bicarbonate, and its amount is 1.2 to 1.5 times the amount of the compound of formula I-3.

[0025] In one embodiment of the present invention, in step 1, the reaction temperature is 60~95℃, preferably 80~85℃, and the holding time is 8~12h.

[0026] In one embodiment of the present invention, in step 1, acetic anhydride is added as a reaction terminator after the reaction is completed, and the amount of acetic anhydride is 5 to 10% of the amount of structural formula I-3.

[0027] In one embodiment of the present invention, in step 2, during the diazotization reaction, the mass of sulfuric acid is 6 to 10 times the mass of the compound of formula I-1, and the molar amount of nitrosylsulfuric acid is 1.05 to 1.2 times the amount of substance of the compound of formula I-1. In one embodiment of the present invention, in step 2, the reaction temperature is set at -5~10℃, preferably -3~3℃; In one embodiment of the present invention, in step 2, the dripping time of nitrosyl sulfuric acid is controlled at 0.5~1h, and after the dripping is completed, the heat preservation time is controlled at 10min~2h.

[0028] In one embodiment of the present invention, in step 3, the amount of water used in the reaction is 4 to 5 times the sum of the masses of all substances, and the amount of sulfuric acid used is determined by the pH value to ensure that the pH of the system is between 3 and 4.

[0029] In one embodiment of the present invention, in step 3, the amount of compound of structural formula I-4 is 1.05 to 1.1 times the amount of compound of formula I-1 in the diazo solution.

[0030] In one embodiment of the present invention, in step 3, the amount of aminosulfonic acid is 5 to 10% of the amount of nitrosylsulfonic acid.

[0031] In one embodiment of the present invention, in step 3, Pingpingjia O-25 is a dispersant, and the amount used is 1 to 2% of the total system mass.

[0032] In one embodiment of the present invention, the reaction temperature in step 3 is -5~10℃.

[0033] In one embodiment of the present invention, in step 3, the dripping time of the diazo solution is controlled at about 2 hours, and the temperature is maintained for 2 to 8 hours after the dripping is completed.

[0034] In one embodiment of the present invention, in step 3, after the reaction is completed, the temperature is slowly raised to 60~95°C and kept at that temperature for 2~3 hours.

[0035] In one embodiment of the present invention, in step 3, after the above reaction is completed, the product is hot filtered, washed with hot water until the wash water is colorless, and then dried at 100°C for 12 hours to ensure that the moisture content is less than 0.1%, thus obtaining the dried product.

[0036] This invention also specifically provides a dyeing method for improving the color fastness of spandex using azo disperse orange dyes, comprising: Azo disperse orange dye, MF (sodium naphthalene sulfonate), sodium lignin sulfonate and water are mixed and ground, then diluted with water to prepare an initial dye bath. The pH of the initial dye bath is adjusted to 4-12, and then a leveling agent is added to obtain the dye bath. Finally, polyester-ammonia blended fibers are placed in the obtained dye bath for dyeing.

[0037] In one embodiment of the present invention, the mass ratio of azo disperse orange dye to MF is 1:0.5~1.5. Specifically, 1:1 is optional.

[0038] In one embodiment of the present invention, the mass ratio of azo disperse orange dye to sodium lignosulfonate is 1:0.5~0.8. Specifically, 1:0.5 is optional.

[0039] In one embodiment of the present invention, the particles are ground to a particle size of about 500 nm.

[0040] In one embodiment of the present invention, the dispersion concentration of the dye in the initial dye bath is 1% to 3%.

[0041] In one embodiment of the present invention, the leveling agent is A-80 (arylphenol polyoxyethylene ether). The mass ratio of azo disperse orange dye to the leveling agent is 1:0.5~0.8. Specifically, 1:0.6 is optional.

[0042] In one embodiment of the present invention, the polyester-spandex blended fiber contains 80% polyester and 20% spandex.

[0043] In one embodiment of the present invention, the dye bath and the polyester-spandex blended fiber are dyed at a bath ratio of 1:40.

[0044] In one embodiment of the present invention, the specific dyeing process conditions are as follows: programmed temperature rise, 5℃ / min to 80℃, then 2℃ / min to 130℃ for dyeing for 40 min, cooling down to 80℃ and holding for 0.5 h, cooling down to room temperature, and then washing the obtained fabric sample with hot water to finally obtain a polyester-ammonia blended dyed fabric sample.

[0045] The present invention provides a polyester-ammonia blended dyeing product based on the above method.

[0046] The present invention also provides the application of the above-mentioned polyester-spandex blended dyed products in clothing, medical pressure garments, and household goods.

[0047] Beneficial effects 1) The N-benzene ring substituents present in all the disperse orange dye compounds provided by this invention significantly enhance hydrophobicity and strengthen the van der Waals forces with the spandex molecular chain, making it less likely for the dye to desorb from the hydrophobic region of the spandex, and significantly improving the wash fastness.

[0048] 2) The N-benzene ring substituents present in all the disperse orange dye compounds provided by this invention increase both volume and rigidity, making it more difficult to diffuse and migrate in the amorphous region of spandex. Once dyed, spandex will be more stable, and the fastness to rubbing and wet treatment will be improved.

[0049] 3) The N-benzene ring substituents present in all the disperse orange dye compounds provided by this invention have hydrophobicity and volume that are more compatible with the supramolecular structure of spandex, allowing the dye to be more "firmly" embedded in the fiber and resulting in better overall fastness.

[0050] 4) The N-cyanoethyl substituent in azo disperse dyes is prone to hydrolysis under high-temperature alkaline dyeing conditions, resulting in a lighter color. However, the adjacent N-phenyl ring substituent provided by this invention, due to its sufficiently large size, provides steric hindrance protection to the adjacent cyanoethyl group, significantly expanding the applicable pH range for dyeing from pH 4-8 to pH 4-12. This greatly improves re-dyeing performance compared to acidic conditions. Furthermore, the alkali-resistant dyeing process enables a one-bath method of "washing, scouring, and dyeing" or a one-bath method of "alkali reduction / dyeing," representing a typical example of industrial upgrading driven by technological innovation. The use of alkali-resistant dyes directly addresses the core demands of the current printing and dyeing industry for green, efficient, and high-quality development. Attached Figure Description

[0051] Figure 1 The image shows the UV spectrophotometer detection spectrum of dye 1 obtained in Example 1.

[0052] Figure 2 The image shows the UV spectrophotometer detection spectrum of dye 2 obtained in Example 2.

[0053] Figure 3 The image shows the UV spectrophotometer detection spectrum of dye 3 obtained in Example 3.

[0054] Figure 4 The image shows the UV spectrophotometer detection spectrum of dye 4 obtained in Example 4.

[0055] Figure 5 The image shows the UV spectrophotometer detection spectrum of dye 5 obtained in Example 5.

[0056] Figure 6 The image shows the UV spectrophotometer detection spectrum of dye 6 obtained in Example 6.

[0057] Figure 7The image shows the UV spectrophotometer detection spectrum of dye 7 obtained in Example 7.

[0058] Figure 8 The image shows the UV spectrophotometer detection spectrum of dye 8 obtained in Example 8.

[0059] Figure 9 This is the proton NMR spectrum of dye 1.

[0060] Figure 10 This is the proton NMR spectrum of dye 2.

[0061] Figure 11 The image shows the proton NMR spectrum of dye 3.

[0062] Figure 12 This is the proton NMR spectrum of dye 4.

[0063] Figure 13 The images show the dyeing results of the fabric samples obtained from Examples 1 to 8. Detailed Implementation

[0064] The source of raw materials involved in this invention: 2,6-Dichloro-4-nitroaniline, o-chloro-4-nitroaniline, 2-chloro-6-bromo-4-nitroaniline, and 4-nitroaniline were all purchased from Shanghai Maclean Biochemical Technology Co., Ltd. 93% sulfuric acid, 40% nitrosyl sulfuric acid, aminosulfonic acid, sodium bicarbonate, acetic anhydride, sodium hydroxide, and acetone were all purchased from Sinopharm Chemical Reagent Co., Ltd. Pingpingjia O-25 was purchased from Jiangsu Haian Petrochemical Plant; m-Methanesulfonylaniline, N-ethyl-m-toluidine, N-cyanoethyl-m-toluidine, N-cyanoethylaniline, and N-ethylaniline were all purchased from Shanghai Maclean Biochemical Technology Co., Ltd. 4-chlorobenzyl chloride, 3-chloro-4-methylbenzyl chloride, 3-nitro-4-methylbenzyl chloride, (2-chloroethyl)benzene, and 1-(4-methylphenyl)-2-chloroethane were all purchased from Shanghai Maclean Biochemical Technology Co., Ltd. MF, sodium lignosulfonate, and leveling agent were all supplied by Penglai Jiaxin Dyestuff & Chemical Co., Ltd.

[0065] Disperse Orange 41, Disperse Orange 33, Disperse Orange 44, and Disperse Red 5 were all supplied by Zhejiang Boao Dyestuff Industry Co., Ltd., while the precursor of Disperse Red 343, Disperse Red 1, and Disperse Brown 4 were supplied by Penglai Jiaxin Dyestuff Chemical Co., Ltd.

[0066] Example 1 The synthetic route for dye 1 is shown below:

[0067]

[0068] (1) 60g of water, 15g (0.111mol) of N-ethyl-m-toluidine, 19.7g (0.122mol) of 2,4-dichlorotoluene, and 14g of sodium bicarbonate were put into a four-necked flask. Stirring was started, the temperature was raised to 85℃ and kept for 4h, then the temperature was raised to 95℃ and kept for 6h. After the reaction was completed, 1g of acetic anhydride was added, and stirring was continued for 2h. The mixture was poured into a separatory funnel and allowed to stand for separation. The lower water layer was discharged, and 100g of water was added again. The mixture was shaken for a while, and then allowed to stand again. The lower water layer was discharged to obtain 26g of yellow-brown oily dye intermediate 1.

[0069] (2) Add 60g of 93% sulfuric acid to a 250ml four-necked flask, add 21.8g (0.105mol) of 2,6-dichloro-4-nitroaniline, cool down to below 10℃, and start adding 14.68g (0.1155mol) of 40% nitrosyl sulfuric acid. Keep the reaction at the temperature for 2h to obtain a diazonium solution for later use.

[0070] (3) Add 400g of water and 5g of 93% sulfuric acid to a 1000ml four-necked flask, add a batch (26g) of dye intermediate obtained in step (1), 1g of aminosulfonic acid, and 0.25g of Pingpingjia O-25 auxiliary agent, and cool to below 10℃. Start adding 92g of diazonium solution obtained in step (2) dropwise. After the addition is complete, keep warm for more than 6 hours, and take the complete reaction of diazonium salt as the endpoint. When the endpoint is reached, raise the temperature to 70℃ and keep warm for 2 hours. Hot filter, wash the filter cake with hot water until the wash water is colorless, and dry the obtained wet product in an oven at 100℃ to obtain orange-red dry dye 1 (41.1g).

[0071] Example 2 The synthetic route for dye 2 is shown below:

[0072]

[0073] (1) 100g of water, 25g (0.1342mol) of m-methanesulfonylaniline, 22.7g (0.141mol) of 4-chlorobenzyl chloride and 13.5g of sodium bicarbonate were put into a four-necked flask, stirred, heated to 65℃ and kept at that temperature for 2h, then heated to 80℃ and kept at that temperature for 4h, then heated to 95℃ and kept at that temperature for 4h. After the reaction was completed, 1g of acetic anhydride was added, and stirring was continued for 2h. The mixture was poured into a separatory funnel and allowed to stand to separate into layers. The lower water layer was removed, and 100g of water was added again. The mixture was shaken for a while and allowed to stand again. The lower water layer was removed to obtain a yellowish-brown oily dye intermediate (33.7g).

[0074] (2) 60g of 93% sulfuric acid was put into a 250ml four-necked flask, and 10g (0.0483mol) of 2,6-dichloro-4-nitroaniline was added. The temperature was lowered to below 10℃, and 16.1g (0.0507mol) of 40% nitrosyl sulfuric acid was added dropwise. The reaction was kept at the temperature for 2h to obtain 82g of diazonium solution for later use.

[0075] (3) Add 450g of water and 6g of 93% sulfuric acid to a 1000ml four-necked flask, add 16.3g (0.05313mol) of yellowish-brown oily dye 2 intermediate, 1g of aminosulfonic acid, and 0.25g of Pingpingjia O-25 auxiliary agent, and cool to below 10℃. Start adding 82g of diazonium solution dropwise, and keep warm for more than 6 hours after the addition is complete, until the diazonium salt reaction is complete. After the endpoint is reached, raise the temperature to 85℃ and keep warm for 2 hours. Filter hot, wash the filter cake with hot water until the wash water is colorless, and dry the obtained wet product in an oven at 100℃ to obtain dark orange dry dye 2 (22.3g).

[0076] Example 3 The synthetic route for dye 3 is shown below:

[0077]

[0078] (1) 100g of water, 25g (0.1849mol) of N-ethyl-m-toluidine, 36g (0.2034mol) of 3-chloro-4-methylbenzyl chloride and 23.3g of sodium bicarbonate were put into a four-necked flask, stirred, heated to 65℃ and kept at that temperature for 2h, then heated to 80℃ and kept at that temperature for 12h. After the reaction was completed, 1.2g of acetic anhydride was added, and stirring was continued for 2h. The mixture was poured into a separatory funnel and allowed to stand to separate into layers. The lower water layer was removed, and 100g of water was added again. The mixture was shaken for a while and allowed to stand again. The lower water layer was removed to obtain 40.5g of blackish-brown oily dye intermediate 3.

[0079] (2) 60g of 93% sulfuric acid was put into a 250ml four-necked flask, and 10g (0.058mol) of o-chloro-4-nitroaniline was added. The temperature was lowered to below 10℃, and 20.27g (0.0638mol) of 40% nitrosyl sulfuric acid was added dropwise. The reaction was kept warm for 2h to obtain 85g of diazonium solution for later use.

[0080] (3) Add 600g of water and 10g of 93% sulfuric acid to a 1000ml four-necked flask, add 16.9g (0.06264mol) of dark brown oily dye 3 intermediate, 1.5g of aminosulfonic acid, and 0.6g of Pingpingjia O-25 auxiliary agent. Cool down to below 10℃, and start adding 85g of diazonium solution dropwise. After the addition is complete, keep warm for more than 6 hours, and take the reaction of diazonium salt as the endpoint. When the endpoint is reached, raise the temperature to 80℃ and keep warm for 2 hours. Hot filter, wash the filter cake with hot water until the wash water is colorless, and dry the obtained wet product in an oven at 100℃ to obtain dark orange dry dye 3 (22.5g). Example 4 The synthetic route for dye 4 is shown below:

[0081]

[0082] (1) 100g of water, 25g (0.156mol) of N-cyanoethyl m-toluidine, 32.8g (0.1872mol) of 3-chloro-4-methylbenzyl chloride and 19.6g of sodium bicarbonate were put into a four-necked flask, stirred, heated to 65℃ and kept at that temperature for 2h, then heated to 75℃ and kept at that temperature for 6h, then heated to 90℃ and kept at that temperature for 4h. After the reaction was completed, 1.5g of acetic anhydride was added, and stirring was continued for 2h. The mixture was poured into a separatory funnel and allowed to stand to separate into layers. The lower water layer was removed, and 100g of water was added again. The mixture was shaken for a while, allowed to stand again, and the lower water layer was removed to obtain 38g of black brown oily dye intermediate 4.

[0083] (2) Add 60g of 93% sulfuric acid to a 250ml four-necked flask, add 10g (0.058mol) of o-chloro-4-nitroaniline, cool down to below 10℃, and start adding 20.27g (0.0638mol) of 40% nitrosyl sulfuric acid. Keep the reaction at the temperature for 2h to obtain 75g of diazonium solution for later use.

[0084] (3) Add 600g of water and 10g of 93% sulfuric acid to a 1000ml four-necked flask, add 20.78g (0.0696mol) of dark brown oily dye 4 intermediate, 1.2g of aminosulfonic acid, and 0.5g of Pingpingjia O-25 auxiliary agent. Cool down to below 10℃, and start adding 75g of diazonium solution dropwise. After the addition is complete, keep warm for more than 6 hours, and take the reaction of diazonium salt as the endpoint. When the endpoint is reached, raise the temperature to 80℃ and keep warm for 2 hours. Filter hot, wash the filter cake with hot water until the wash water is colorless, and dry the obtained wet product in an oven at 100℃ to obtain orange dry dye 4 (23g).

[0085] Example 5 The synthetic route for dye 5 is shown below:

[0086]

[0087] (1) 100g of water, 25g (0.171mol) of N-cyanoethyl aniline, 36g (0.197mol) of 3-nitro-4-methylbenzyl chloride and 21.5g of sodium bicarbonate were put into a four-necked flask, stirred, heated to 65℃ and kept at that temperature for 2h, then heated to 75℃ and kept at that temperature for 2h, then heated to 85℃ and kept at that temperature for 12h. After the reaction was completed, 1.2g of acetic anhydride was added and stirred for another 2h. The mixture was poured into a separatory funnel and allowed to stand to separate into layers. The lower water layer was removed, and 100g of water was added again. The mixture was shaken for a while and allowed to stand again. The lower water layer was removed to obtain 42g of brown oily dye intermediate 5.

[0088] (2) 60g of 93% sulfuric acid was put into a 250ml four-necked flask, and 10g (0.040mol) of 2-chloro-6-bromo-4-nitroaniline was added. The temperature was lowered to below 10℃, and 13.26g (0.042mol) of 40% nitrosyl sulfuric acid was added dropwise. The reaction was kept warm for 2h to obtain 74.5g of diazonium solution, which was then set aside for use.

[0089] (3) Add 500g of water and 8g of 93% sulfuric acid to a 1000ml four-necked flask, add 14.2g (0.048mol) of brown oily dye intermediate 5, 1g of aminosulfonic acid, and 0.5g of Pingpingjia O-25 auxiliary agent. Cool down to below 10℃, and start adding 74.5g of diazonium solution dropwise. After the addition is complete, keep warm for more than 6 hours, and take the reaction of diazonium salt as the endpoint. When the endpoint is reached, raise the temperature to 95℃ and keep warm for 2 hours. Filter hot, wash the filter cake with hot water until the wash water is colorless, and dry the obtained wet product in an oven at 100℃ to obtain 5 (18.3)g of orange dry dye.

[0090] Example 6 The synthetic route for dye 6 is shown below:

[0091]

[0092] (1) 100g of water, 25g (0.1849mol) of N-ethyl-m-toluidine, 36.5g (0.197mol) of 3-nitro-4-methylbenzyl chloride and 21.5g of sodium bicarbonate were put into a four-necked flask, stirred, heated to 80℃ and kept at that temperature for 16h, then heated to 90℃ and kept at that temperature for 2h. After the reaction was completed, 1.2g of acetic anhydride was added, and stirring was continued for 2h. The mixture was poured into a separatory funnel and allowed to stand for separation. The lower water layer was removed, and 100g of water was added again. The mixture was shaken for a while and allowed to stand again. The lower water layer was removed to obtain 42.6g of brown oily dye intermediate 6.

[0093] (2) Add 60g of 93% sulfuric acid to a 250ml four-necked flask, add 10g (0.040mol) of 2-chloro-6-bromo-4-nitroaniline, cool down to below 10℃, and start adding 13.26g (0.042mol) of 40% nitrosyl sulfuric acid. Keep the reaction at the temperature for 2h to obtain 74g of diazonium solution for later use.

[0094] (3) Add 500g of water and 8g of 93% sulfuric acid to a 1000ml four-necked flask, add 13.6g (0.048mol) of brown oily dye 6 intermediate, 1g of aminosulfonic acid, and 0.5g of Pingpingjia O-25 auxiliary agent. Cool down to below 10℃, and start adding 74g of diazonium solution dropwise. After the addition is complete, keep warm for more than 6 hours, and take the reaction of diazonium salt as the endpoint. When the endpoint is reached, raise the temperature to 85℃ and keep warm for 2 hours. Filter hot, wash the filter cake with hot water until the wash water is colorless, and dry the obtained wet product in an oven at 100℃ to obtain orange dry dye 6 (18.6g).

[0095] Example 7 The synthetic route for dye 7 is shown below:

[0096]

[0097] (1) 100g of water, 25g (0.1849mol) N-ethyl-m-toluidine, 27.7g (0.197mol) (2-chloroethyl)benzene and 21.5g of sodium bicarbonate were put into a four-necked flask, stirred, heated to 60℃ and kept at that temperature for 2h, then heated to 80℃ and kept at that temperature for 2h, then heated to 95℃ and kept at that temperature for 16h. After the reaction was completed, 1.5g of acetic anhydride was added, and stirring was continued for 2h. The mixture was poured into a separatory funnel and allowed to stand to separate into layers. The lower water layer was removed, and 100g of water was added again. The mixture was shaken for a while and allowed to stand again. The lower water layer was removed to obtain 36.3g of brown oily dye intermediate 7.

[0098] (2) Add 60g of 93% sulfuric acid to a 250ml four-necked flask, add 10g (0.0724mol) of 4-nitroaniline, cool down to below 10℃, and start adding 25.3g (0.0796 mol) of 40% nitrosyl sulfuric acid. Keep the reaction at the temperature for 2h to obtain 88g of diazonium solution for later use.

[0099] (3) Add 500g of water and 8g of 93% sulfuric acid to a 1000ml four-necked flask, add 20.8g (0.087mol) of brown oily dye 7 intermediate, 1.5g of aminosulfonic acid, and 0.8g of Pingpingjia O-25 auxiliary agent. Cool down to below 10℃, and start adding 88g of diazonium solution dropwise. After the addition is complete, keep warm for more than 6 hours, and take the reaction of diazonium salt as the endpoint. When the endpoint is reached, raise the temperature to 90℃ and keep warm for 2 hours. Filter hot, wash the filter cake with hot water until the wash water is colorless, and dry the obtained wet product in an oven at 100℃ to obtain orange dry dye 7 (23g).

[0100] Example 8 The synthetic route for dye 8 is shown below:

[0101]

[0102] (1) 100g of water, 25g (0.206mol) of N-ethylaniline, 35g (0.227mol) of 1-(4-methylphenyl)-2-chloroethane and 26g of sodium bicarbonate were put into a four-necked flask, stirred, heated to 65℃ and kept at that temperature for 12h, then heated to 80℃ and kept at that temperature for 6h. After the reaction was completed, 1.2g of acetic anhydride was added and stirred for 2h. The mixture was poured into a separatory funnel and allowed to stand to separate into layers. The lower water layer was removed, and 100g of water was added again. The mixture was shaken for a while and allowed to stand again. The lower water layer was removed to obtain 39.5g of blackish-brown oily dye intermediate 8.

[0103] (2) Add 60g of 93% sulfuric acid to a 250ml four-necked flask, add 10g (0.0724mol) of 4-nitroaniline, cool down to below 10℃, and start adding 25.3g (0.0796 mol) of 40% nitrosyl sulfuric acid. Keep the reaction at the temperature for 2h to obtain 86g of diazonium solution for later use.

[0104] (3) Add 500g of water and 8g of 93% sulfuric acid to a 1000ml four-necked flask, add 20.8g (0.08mol) of dark brown oily dye 8 intermediate, 1.5g of aminosulfonic acid, and 0.8g of Pingpingjia O-25 auxiliary agent. Cool down to below 10℃ and start adding diazonium solution dropwise. After the addition is complete, keep warm for more than 6 hours until the diazonium salt reaction is complete. When the endpoint is reached, heat up to 90℃ and keep warm for 2 hours. Filter hot, wash the filter cake with hot water until the wash water is colorless, and dry the obtained wet product in an oven at 100℃ to obtain orange dry dye 8 (25.3g).

[0105] Application Example 1 Grind 0.5g of dye 1, 0.5g of MF, 0.25g of sodium lignosulfonate, and 1g of water in a mortar until the particle size is approximately 500nm. Prepare a 25ml dye bath using deionized water, and then adjust the pH of the dye bath to 10 using a 0.4g / L sodium hydroxide solution. After adjustment, add a few drops of leveling agent A-80 (arylphenol polyoxyethylene ether) (approximately 0.3g) using a 5ml disposable dropper. Then, dye the polyester / spandex blended fiber (80% polyester, 20% spandex) at a liquor ratio of 1:40. The dyeing process is as follows: programmed temperature increase, increasing to 80℃ at 5℃ / min, then increasing to 130℃ at 2℃ / min for 40 minutes, cooling to 80℃ and holding for 0.5 hours, then cooling to room temperature. The resulting fabric sample is then washed with hot water to obtain polyester / spandex blended dyed fabric sample 1.

[0106] Application Examples 2-8 By replacing dye 1 in Application Example 1 with dyes 2-8 respectively, while keeping other conditions unchanged, and finally combining with Application Example 1, eight dyed fabric samples 1-8 of polyester-spandex blended fibers were obtained. The polyester-spandex blended fabric samples were dyed according to GB / T8427.2008 "Textiles - Tests for color fastness - Color fastness to artificial light: Xenon arc" and GB / T6152 The 1997 standard "Tests for Color Fastness of Textiles - Heat and Pressure Fastness" tests the color fastness by using the residual liquid method to determine the dyeing rate.

[0107] Test Example 1 The crude filter cakes of dyes 1 to 8 were dissolved in acetone and recrystallized to obtain pure products, which were then analyzed by ultraviolet spectrophotometry and proton nuclear magnetic resonance spectroscopy. Figures 1-8 The UV absorption spectra of dyes 1 through 8 are shown. Figures 9-12 The NMR spectra of dyes 1 to 4 are shown below.

[0108] Dissolved in acetone at a uniform concentration, the maximum absorption wavelength λ was measured using a UV-Vis spectrophotometer. max The molar extinction coefficient ε and the results are shown in Table 1: Table 1

[0109] Test Example 2 The fabric samples obtained from Examples 1-8 were tested using a Data Color 600 colorimeter, and the results are as follows: Figure 13 As shown.

[0110] Test Example 3 The fabric samples obtained from Examples 1-8 were subjected to various fastness tests, and the test results are shown in Table 2: Table 2

[0111] Comparative Example 1 Following the method in Application Example 1, other disperse orange dyes with similar structures and whose N,N-substituents of the azo component do not contain benzene ring structures (as shown in Table 3) were selected as comparative examples to dye polyester-spandex blends. The resulting dyed fabric samples were then subjected to fastness testing. The comparative samples are shown in Table 3 below: Table 3

[0112] The corresponding test results are shown in Table 4 below: Table 4

[0113] Comparative Example 2 Based on Application Example 1, the dye bath was adjusted to pH conditions of 4.5, 6, 8, 10, and 12, respectively. Four dyes from Examples 1-4 and four dyes from Comparative Examples 1-4 were selected, and a uniform dyeing process was used to dye polyester-spandex blended fabric samples. The dye uptake rate of the dyed fabric samples was tested, and the results are shown in Table 5 below: Table 5

[0114] According to the technical solution and corresponding test data provided by the present invention, the azo disperse orange dye containing N-benzene ring substituents provided by the present invention exhibits superior and unique properties in the dyeing of polyester-ammonia blended fabrics, regardless of its wide pH range, dyeing rate, and various fastness properties.

[0115] The embodiments provided above are not intended to limit the scope of the invention, nor are the described steps intended to limit the order of execution. Any obvious modifications made to the invention by those skilled in the art based on existing common knowledge also fall within the scope of protection defined by the claims.

Claims

1. A dyeing method for improving the color fastness of spandex using an azo-based disperse orange dye, characterized by, The structure of the azo disperse orange dye is shown as formula I: Formula I, In the formula, R1 is -H, -Cl or -Br; R2 is -H, -Cl or -Br; R3 is -H, -CH3 or -NHSO2CH3; R4 is -H, -CH3, -CH2CH3, -CH2CH2CN or -COCH2COCH3; R5 is -H, -CH3 or -Cl; R6 is -H, -CH3, -Cl or -NO2; and n is 0, 1 or 2.

2. The dyeing method according to claim 1, characterized in that, The azo disperse orange dye is specifically selected from the group consisting of: 、 、 、 、 、 、 、 。 3. The dyeing method according to claim 1 or 2, characterized in that, The method comprises the following steps: mixing, grinding and diluting the azo disperse orange dye, MF, sodium lignosulfonate and water to prepare an initial dye bath, adjusting the pH of the obtained initial dye bath to 4-12, adding a leveling agent dropwise to obtain a dye bath, and finally dyeing the polyester-spandex blended fabric in the dye bath.

4. The dyeing method according to claim 3, characterized in that, The mass ratio of the azo disperse orange dye to the MF is 1:0.5-1.

5.

5. The dyeing method according to claim 3, characterized in that, The mass ratio of the azo disperse orange dye to the sodium lignosulfonate is 1:0.5-0.

8.

6. The dyeing method according to claim 3, characterized in that, The leveling agent is aryl phenol polyoxyethylene ether, and the mass ratio of the azo disperse orange dye to the leveling agent is 1:0.5-0.

8.

7. The dyeing method according to claim 3, characterized by, The polyester-spandex blended fabric contains 80% polyester and 20% spandex.

8. The dyeing method according to claim 3, characterized by, The dye bath and the polyester-spandex blended fabric are dyed at a bath ratio of 1:40, and the specific process conditions of the dyeing are as follows: programmed temperature rising, 5℃ / min to 80℃, then 2℃ / min to 130℃ for dyeing for 40 min, cooling to 80℃ for 0.5h, cooling to room temperature, washing the obtained cloth sample in hot water, and finally obtaining a polyester-spandex blended dyed cloth sample.

9. A polyester-spandex blended dyed product prepared by the method of any one of claims 1-8.

10. The polyester-spandex blended dyed product of claim 9 for use in clothing, medical compression garments and home products.

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