A three-colour one-bath dyeing process

Abstract

The present application relates to cloth dyeing and finishing technical field, especially to a three-color one-bath dyeing method, comprising the following steps: injecting water into a dyeing container, immersing cloth in water, using disperse dye, cationic dye and blended dye for dyeing; preparing a fixing liquid by mixing fixing agent with 80-90 DEG C water; maintaining the temperature of the fixing liquid at 80-90 DEG C, immersing the cloth after step S1, cooling to 20-30 DEG C after completing immersion, and placing for 10-12 hours; the fixing agent comprises soluble divalent nickel salt and fixing polymer, and the fixing polymer is a polymer with multiple terpyridyl groups and multiple isocyanate groups. In the method of the present application, special fixing agent is used, which is suitable for the system with coexisting dyes with different charges, can play a role on disperse dye, cationic dye and blended dye, and can achieve good fixing effect.

Description

Technical Field

[0001] This invention relates to the field of fabric dyeing and finishing technology, and in particular to a three-color one-bath dyeing method. Background Technology

[0002] Three-color one-bath dyeing involves adding three dyes (including cationic dyes, disperse dyes, blended dyes, or acid dyes) to the same dye bath for dyeing. Compared with traditional multi-bath, multi-step dyeing (such as two-bath dyeing), it has the advantages of shorter process time, higher production efficiency, and can reduce energy and water consumption, as well as wastewater discharge.

[0003] In the three-color one-bath dyeing process, the dyes used include positively charged dyes (such as cationic dyes) and negatively charged dyes (such as disperse dyes). During color fixation, existing fixing agents often struggle to simultaneously act on dyes with different charges, or the color fixation effect is poor. For example, patent CN114592360B uses modified chitosan and polyurethane dyeing auxiliaries as fixing agents. These form a thin film on the surface of the fabric fibers. Both modified chitosan and polyurethane dyeing auxiliaries can bind to the anions of the dyes through ionic bonds, and modified chitosan can also bind to the fabric fibers through hydrogen bonds. This cross-linking of the fixing agent, dye, and fabric fibers achieves color fixation. Compared to small-molecule fixing agents, this large-molecule fixing agent can achieve better color fixation by utilizing intramolecular cohesion and entanglement with the fabric fibers. However, when used for color fixation of three-color one-bath dyed fabrics, the fixing agent can only bind to the fabric fibers and cationic dyes through hydrogen bonds, and the strength of hydrogen bonds is relatively weak, thus limiting the effect on improving color fastness. Summary of the Invention

[0004] To address the technical problem of poor color-fixing effect of existing fixing agents when used in three-color one-bath dyeing, this invention provides a three-color one-bath dyeing method. In this method, a soluble divalent nickel salt and a polymer containing multiple terpyridine groups and multiple isocyanate groups are used as fixing agents. This method can produce good color-fixing effects on disperse dyes, cationic dyes, and blended dyes, significantly improving color fastness.

[0005] The specific technical solution of this invention is as follows: A three-color one-bath staining method includes the following steps: S1: Pour water into the dyeing container, immerse the fabric in the water, and dye it using disperse dyes, cationic dyes, and blended dyes; S2: Mix the color-fixing agent with water at 80~90℃ to make a color-fixing solution; maintain the temperature of the color-fixing solution at 80~90℃ and impregnate the fabric after step S1; after impregnation, cool down to 20~30℃ and leave for 10~12 hours. In step S2, the fixing agent includes a soluble divalent nickel salt and a fixing polymer, wherein the fixing polymer is a polymer with multiple terpyridine groups and multiple isocyanate groups.

[0006] The fixing agent used in this invention functions in the following ways: the long molecular chains of the fixing polymer can form physical entanglement with the fabric fibers; the isocyanate groups in the fixing polymer can react with the hydroxyl and amino groups on the dye and fabric fibers to form covalent crosslinks; the terpyridine groups on the fixing polymer can react with Ni... 2+ Coordination bonds are formed, and dyes and fabric fibers also contain substances that can interact with Ni. 2+ Coordinating groups, therefore, via Ni 2+ This invention enables the formation of bridges between the fixing polymer and the dye, and between the fixing polymer and the fabric fibers. Through these effects, the fixing agent of this invention allows dye molecules to bind more firmly to the fibers, improving color fastness. Furthermore, the fixing agent of this invention is suitable for systems where positively charged dyes (such as cationic dyes) and negatively charged dyes (such as disperse dyes) coexist. It can fix dyes with different charges, and the coordinate bonds are stronger than hydrogen bonds, resulting in a better color fastening effect.

[0007] Furthermore, when polymer + metal ions are used as fixing agents, the metal ions form coordination bonds with multiple groups in the polymer in the fixing solution. However, when this is applied to the fabric, the limited coordination number of the metal ions and steric hindrance prevent them from forming further coordination bonds with the fabric fibers and dyes. This hinders the interaction between the terpyridine groups and the fabric fibers and dyes via Ni... 2+ Furthermore, this interconnectedness hinders the polymer from encapsulating onto the fabric fibers and forming a physical entanglement, resulting in poor colorfastness. In this invention, terpyridine is used as the group in the color-fixing polymer that coordinates with metal ions, and Ni is employed... 2+ As a metal ion, when combined with a specific color-fixing process, it can achieve the following effects: when the temperature of the color-fixing solution is controlled at 80~90℃, the terpyridine group reacts with Ni. 2+ The coordination bonds between them are in a dissociated state at this temperature, and the terpyridine groups are in a free state (the terpyridine groups are not separated by Ni). 2+ (Combined together), after being impregnated onto the fabric surface and then cooled, terpyridine and Ni can be combined. 2+ Forming coordinate bonds, which in this way is beneficial for Ni 2+ The free terpyridine groups in the color-fixing polymer form bridges between the fabric fibers and the dye, thereby fixing the color-fixing polymer on the fibers and fixing the dye molecules on the color-fixing polymer. It also helps the color-fixing polymer to wrap around the fabric fibers and form physical entanglement with them, thus improving the color fastness.

[0008] Preferably, step S1 specifically includes the following steps: S1.1: Pour water into the dyeing container, immerse the fabric in the water, heat to 50~60℃, and add disperse dye; S1.2: Heat to 75~85℃, add cationic dye, keep warm for 5~10 min, then heat to 120~130℃ and keep warm for 15~20 min; S1.3: Cool to 85~95℃, add dyeing auxiliaries, mix well, then add blended dyes, keep warm for 20~40 minutes, cool down and wash with water, and dry.

[0009] By using the above method, the mutual interference between the three dyes can be reduced effectively, and a better dyeing effect can be achieved.

[0010] Preferably, in step S2, the method for preparing the color-fixing polymer includes the following steps: mixing pentaerythritol polyoxyethylene ether and diisocyanate, reacting at 80~90℃ for 1~2h under inert gas protection, adding 2,2':6',2”-terpyridine-4'-methanol, and continuing to react at 80~90℃ for 0.5~1h to obtain the color-fixing polymer; the molar ratio of pentaerythritol polyoxyethylene ether, diisocyanate and 2,2':6',2”-terpyridine-4'-methanol is 1:6~8:0.1~0.5.

[0011] Pentaerythritol polyoxyethylene ether is synthesized by ring-opening polymerization of pentaerythritol and ethylene oxide, and its structural formula is as follows: .

[0012] By utilizing the four hydroxyl groups in pentaerythritol polyoxyethylene ether and the two isocyanate groups in diisocyanate, the two can be polymerized to generate a polymer with terminal isocyanate groups. By using the hydroxyl groups in 2,2':6',2”-terpyridine-4'-methanol to react with the terminal isocyanate groups, terpyridine groups can be grafted onto the polymer, thereby obtaining a color-fixing polymer with multiple isocyanate groups and multiple terpyridine groups.

[0013] Preferably, the preparation method of the pentaerythritol polyoxyethylene ether includes the following steps: taking pentaerythritol and ethylene oxide in a molar ratio of 1:24~28; adding pentaerythritol and catalyst into a reaction vessel, mixing well, replacing the air in the reaction vessel with an inert gas, raising the temperature to 150~160℃, and adjusting the inert gas pressure to 0.1~0.2MPa; maintaining the temperature at 150~160℃, introducing a first portion of ethylene oxide into the reaction vessel, reacting until the gas pressure no longer decreases, and dehydrating; then maintaining the temperature at 150~160℃, introducing a second portion of ethylene oxide, reacting until the gas pressure no longer decreases, and dehydrating to obtain pentaerythritol polyoxyethylene ether.

[0014] The pentaerythritol polyoxyethylene ether prepared by the above method has pentaerythritol as the core and is connected with a relatively long polyether chain, which can introduce a certain length of flexible chain segment into the color-fixing polymer, which is beneficial to the formation of physical entanglement between the color-fixing polymer and the fabric fibers.

[0015] Preferably, the molar ratio of the first portion of ethylene oxide to the second portion of ethylene oxide is 1:1.3~2.0.

[0016] Preferably, the molar ratio of pentaerythritol to catalyst is 1:0.01~0.03.

[0017] Preferably, in steps S1.1 to S1.3, the disperse dye, cationic dye, and blended dye are all added by uniform feeding, and the feeding time is 8 to 13 minutes.

[0018] Preferably, in step S1.3, the dyeing auxiliary agent is sodium sulfate, and the dosage is 2~10g / L.

[0019] Preferably, in step S1.2, the heating rate is 0.5~1℃ / min during the process of heating to 75~85℃.

[0020] Preferably, in step S1.2, the specific process of heating to 120~130℃ includes the following steps: heating to 90~100℃ at a rate of 0.6~0.9℃ / min, and then heating to 120~130℃ at a rate of 0.8~1.2℃ / min.

[0021] Preferably, in step S1.3, during the cooling process to 85~95℃, the cooling rate is 1.0~1.8℃ / min.

[0022] Preferably, in steps S1.1 to S1.3, the dosages of the disperse dye, cationic dye, and blended dye are 0.1~0.4 g / L, 0.1~0.4 g / L, and 0.4~0.8 g / L, respectively.

[0023] Preferably, in step S1, the disperse dye includes one or more of Disperse Blue 2BLN, Disperse Yellow E-RGFL, and Disperse Red 3B; the cationic dye includes one or more of Cationic Blue X-BL, Cationic Red X-GRL, and Cationic Golden Yellow X-GL; and the blended dye includes one or more of Blended Blue D-3GL, Blended Red D-GLN, and Blended Yellow D-3RNL.

[0024] Preferably, in step S2, the mass ratio of the fixing polymer to the soluble divalent nickel salt in the fixing agent is 1:0.10~0.25.

[0025] Preferably, in step S2, the content of the fixing agent in the fixing solution is 30~50g / L.

[0026] Preferably, in step S2, after being left to stand for 10-12 hours, the product is washed with water and dried.

[0027] Compared with the prior art, the present invention has the following advantages: (1) In this invention, a soluble divalent nickel salt and a polymer with multiple terpyridine groups and multiple isocyanate groups are used as fixing agents. This is suitable for systems where dyes with different charges coexist. It can work on disperse dyes, cationic dyes and blended dyes, and can achieve better color fixing effect. (2) In the preparation process of the color-fixing polymer, the present invention uses pentaerythritol polyoxyethylene ether with a certain length of polyether chain, which is conducive to the formation of physical entanglement between the color-fixing polymer and the fabric fiber, thereby further improving the color-fixing effect. Detailed Implementation

[0028] The present invention will be further described below with reference to embodiments.

[0029] General Implementation Examples A three-color one-bath staining method includes the following steps: S1: Pour water into the dyeing container, immerse the fabric in the water, and dye it using disperse dyes, cationic dyes, and blended dyes; S2: Mix the color-fixing agent with water at 80~90℃ to make a color-fixing solution; maintain the temperature of the color-fixing solution at 80~90℃ and impregnate the fabric after step S1; after impregnation, cool down to 20~30℃ and leave for 10~12 hours. In step S2, the fixing agent includes a soluble divalent nickel salt and a fixing polymer, wherein the fixing polymer is a polymer with multiple terpyridine groups and multiple isocyanate groups.

[0030] As one specific implementation method, step S1 specifically includes the following steps: S1.1: Pour water into the dyeing container, immerse the fabric in the water, heat to 50~60℃, and add disperse dye; S1.2: Heat to 75~85℃, add cationic dye, keep warm for 5~10 min, then heat to 120~130℃ and keep warm for 15~20 min; S1.3: Cool to 85~95℃, add dyeing auxiliaries, mix well, then add blended dyes, keep warm for 20~40 minutes, cool down and wash with water, and dry.

[0031] In one specific implementation, in steps S1.1 to S1.3, the disperse dye, cationic dye, and blended dye are all added by uniform feeding, and the feeding time is 8 to 13 minutes.

[0032] In one specific implementation, in step S1.3, the dyeing auxiliary agent is sodium sulfate, and the dosage is 2~10g / L.

[0033] In one specific implementation, in step S1.2, the heating rate is 0.5~1℃ / min during the process of heating to 75~85℃; in step S1.2, the specific process of heating to 120~130℃ includes the following steps: heating to 90~100℃ at a rate of 0.6~0.9℃ / min, and then heating to 120~130℃ at a rate of 0.8~1.2℃ / min; in step S1.3, the cooling rate is 1.0~1.8℃ / min during the process of cooling to 85~95℃.

[0034] In one specific implementation, in steps S1.1 to S1.3, the dosages of the disperse dye, cationic dye, and blended dye are 0.1~0.4 g / L, 0.1~0.4 g / L, and 0.4~0.8 g / L, respectively.

[0035] In one specific embodiment, in step S1, the disperse dye includes one or more of Disperse Blue 2BLN, Disperse Yellow E-RGFL, and Disperse Red 3B; the cationic dye includes one or more of Cationic Blue X-BL, Cationic Red X-GRL, and Cationic Golden Yellow X-GL; and the blended dye includes one or more of Blended Blue D-3GL, Blended Red D-GLN, and Blended Yellow D-3RNL.

[0036] In one specific embodiment, step S2 includes the following steps in the preparation method of the color-fixing polymer: S2.1: Take pentaerythritol and ethylene oxide in a molar ratio of 1:24~28; add pentaerythritol and catalyst to a reaction vessel, mix well, replace the air in the reaction vessel with inert gas, raise the temperature to 150~160℃, and adjust the inert gas pressure to 0.1~0.2MPa; maintain the temperature at 150~160℃, introduce the first part of ethylene oxide into the reaction vessel, react until the gas pressure no longer decreases, and dehydrate; then maintain the temperature at 150~160℃, introduce the second part of ethylene oxide, react until the gas pressure no longer decreases, and dehydrate to obtain pentaerythritol polyoxyethylene ether; the molar ratio of the first part of ethylene oxide to the second part of ethylene oxide is 1:1.3~2.0, and the molar ratio of pentaerythritol to catalyst is 1:0.01~0.03; S2.2: After mixing pentaerythritol polyoxyethylene ether and diisocyanate, the mixture is reacted at 80~90℃ for 1~2h under inert gas protection, followed by the addition of 2,2':6',2”-terpyridine-4'-methanol, and the reaction is continued at 80~90℃ for 0.5~1h to obtain a color-fixing polymer; the molar ratio of pentaerythritol polyoxyethylene ether, diisocyanate and 2,2':6',2”-terpyridine-4'-methanol is 1:6~8:0.1~0.5.

[0037] In one specific embodiment, in step S2, the mass ratio of the fixing polymer to the soluble divalent nickel salt in the fixing agent is 1:0.10~0.25.

[0038] In one specific implementation, in step S2, the content of the fixing agent in the fixing solution is 30~50g / L.

[0039] In one specific implementation, in step S2, after being placed for 10-12 hours, the product is washed with water and dried.

[0040] Example 1 The steps for preparing the color-fixing polymer are as follows: (1) Pentaerythritol, ethylene oxide, and sodium formate were prepared according to a molar ratio of 1:25:0.02. Pentaerythritol and sodium formate were added to the polymerization reactor and stirred until homogeneous. The air in the polymerization reactor was replaced with nitrogen three times, and the temperature was raised to 155°C. The nitrogen pressure was adjusted to 0.1 MPa. The temperature inside the polymerization reactor was maintained at 155±5°C. Two-fifths of the ethylene oxide was introduced into the polymerization reactor, and the reaction was stirred until the pressure no longer decreased. Then, low-boiling substances were removed under vacuum. The temperature inside the polymerization reactor was maintained at 155±5°C again, and the remaining ethylene oxide was introduced. The reaction was stirred until the pressure no longer decreased. Then, the product was dried under vacuum to obtain pentaerythritol polyoxyethylene ether.

[0041] (2) According to the molar ratio of 1:6:0.3:0.12, pentaerythritol polyoxyethylene ether, isophorone diisocyanate, 2,2':6',2”-terpyridine-4'-methanol and sodium bisulfite were taken. Pentaerythritol polyoxyethylene ether and isophorone diisocyanate were added to the reaction vessel and stirred evenly. The air in the reaction vessel was replaced with nitrogen three times to maintain the temperature in the reaction vessel at 85±5℃. The reaction was stirred for 1.5h. Then 2,2':6',2”-terpyridine-4'-methanol was added and the temperature in the reaction vessel was maintained at 85±5℃. The reaction was stirred for another 0.5h. Sodium bisulfite was added to block the isocyanate groups to obtain the fixed polymer.

[0042] For polyester / cationically modified polyester / cotton blended fabrics, a three-color one-bath dyeing process is performed, as follows: S1: Pour water into the dyeing container, immerse the fabric in the water, the bath ratio is 1:20, heat to 60℃, add Disperse Blue 2BLN at a uniform feed rate of 0.14g / L, and feed for 10min.

[0043] S2: Heat to 80℃ at a rate of 0.8℃ / min, add cationic red X-GRL at a constant rate of 0.19 g / L for 10 min, hold for 5 min, then heat to 100℃ at a rate of 0.7℃ / min, and then heat to 1250℃ at a rate of 0.8℃ / min for 20 min.

[0044] S3: Cool to 90℃ at a rate of 1.5℃ / min, add sodium sulfate at a dosage of 2g / L, stir evenly for 5min, then add blended yellow D-3RNL at a uniform feeding rate of 0.5g / L for 10min, keep warm for 30min, cool to 70℃, wash with water, and dry.

[0045] S4: Take the color-fixing polymer and nickel nitrate prepared in this example at a mass ratio of 1:0.15, add them to water at 85°C, and control the total addition amount of both in the water to be 40 g / L. Disperse them evenly to obtain a color-fixing solution. Use the color-fixing solution to perform two dips and two pads on the fabric after step S3, controlling the temperature of the color-fixing solution at 85±5°C during the process. After the dips and pads are completed, the padding rate of the fabric is 70%. Allow it to cool naturally to room temperature (24°C), let it stand for 12 hours, then wash it with water and dry it to obtain the dyed fabric.

[0046] Example 2 The steps for preparing the color-fixing polymer are as follows: (1) Pentaerythritol, ethylene oxide, and sodium formate were prepared according to a molar ratio of 1:24:0.01. Pentaerythritol and sodium formate were added to the polymerization reactor and stirred until homogeneous. The air in the polymerization reactor was replaced with nitrogen three times, and the temperature was raised to 155°C. The nitrogen pressure was adjusted to 0.2 MPa. The temperature inside the polymerization reactor was maintained at 155±5°C. One-third of the ethylene oxide was introduced into the polymerization reactor and stirred until the gas pressure no longer decreased. Then, low-boiling substances were removed under vacuum. The temperature inside the polymerization reactor was maintained at 155±5°C again, and the remaining ethylene oxide was introduced and stirred until the gas pressure no longer decreased. Then, the mixture was dried under vacuum to obtain pentaerythritol polyoxyethylene ether.

[0047] (2) According to the molar ratio of 1:8:0.5:0.16, pentaerythritol polyoxyethylene ether, isophorone diisocyanate, 2,2':6',2”-terpyridine-4'-methanol and sodium bisulfite were taken. Pentaerythritol polyoxyethylene ether and isophorone diisocyanate were added to the reaction vessel and stirred evenly. The air in the reaction vessel was replaced with nitrogen three times to maintain the temperature in the reaction vessel at 85±5℃. The reaction was stirred for 1h. Then 2,2':6',2”-terpyridine-4'-methanol was added and the temperature in the reaction vessel was maintained at 85±5℃. The reaction was stirred for another 1h. Sodium bisulfite was added to block the isocyanate groups to obtain the fixed polymer.

[0048] For polyester / cationically modified polyester / cotton blended fabrics, a three-color one-bath dyeing process is performed, as follows: S1: Pour water into the dyeing container, immerse the fabric in the water, the bath ratio is 1:20, heat to 60℃, add Disperse Blue 2BLN at a uniform feed rate of 0.14g / L, and feed for 10min.

[0049] S2: Heat to 80℃ at a rate of 0.8℃ / min, add cationic red X-GRL at a constant rate of 0.19 g / L for 10 min, hold for 5 min, then heat to 100℃ at a rate of 0.7℃ / min, and then heat to 1250℃ at a rate of 0.8℃ / min for 20 min.

[0050] S3: Cool to 90℃ at a rate of 1.5℃ / min, add sodium sulfate at a dosage of 2g / L, stir evenly for 5min, then add blended yellow D-3RNL at a uniform feeding rate of 0.5g / L for 10min, keep warm for 30min, cool to 70℃, wash with water, and dry.

[0051] S4: Take the color-fixing polymer and nickel nitrate prepared in this example at a mass ratio of 1:0.10, add them to water at 80°C, and control the total addition amount of both in the water to be 50 g / L. Disperse them evenly to obtain a color-fixing solution. Use the color-fixing solution to perform two dips and two pads on the fabric after step S3, controlling the temperature of the color-fixing solution at 85±5°C during the process. After the dips and pads are completed, the padding rate of the fabric is 70%. Allow it to cool naturally to room temperature (23°C), let it stand for 10 hours, then wash it with water and dry it to obtain the dyed fabric.

[0052] Example 3 The steps for preparing the color-fixing polymer are as follows: (1) Pentaerythritol, ethylene oxide, and sodium formate were prepared according to a molar ratio of 1:28:0.03. Pentaerythritol and sodium formate were added to the polymerization reactor and stirred until homogeneous. The air in the polymerization reactor was replaced with nitrogen three times, and the temperature was raised to 155°C. The nitrogen pressure was adjusted to 0.13 MPa. The temperature inside the polymerization reactor was maintained at 155±5°C. 3 / 7 of the ethylene oxide was introduced into the polymerization reactor and stirred until the gas pressure no longer decreased. Then, low-boiling substances were removed under vacuum. The temperature inside the polymerization reactor was maintained at 155±5°C again, and the remaining ethylene oxide was introduced and stirred until the gas pressure no longer decreased. Then, the mixture was dried under vacuum to obtain pentaerythritol polyoxyethylene ether.

[0053] (2) According to the molar ratio of 1:7:0.1:0.15, pentaerythritol polyoxyethylene ether, isophorone diisocyanate, 2,2':6',2”-terpyridine-4'-methanol and sodium bisulfite were taken. Pentaerythritol polyoxyethylene ether and isophorone diisocyanate were added to the reaction vessel and stirred evenly. The air in the reaction vessel was replaced with nitrogen three times to maintain the temperature in the reaction vessel at 85±5℃. The reaction was stirred for 2h. Then 2,2':6',2”-terpyridine-4'-methanol was added and the temperature in the reaction vessel was maintained at 85±5℃. The reaction was stirred for another 0.5h. Sodium bisulfite was added to block the isocyanate groups to obtain the fixed polymer.

[0054] For polyester / cationically modified polyester / cotton blended fabrics, a three-color one-bath dyeing process is performed, as follows: S1: Pour water into the dyeing container, immerse the fabric in the water, the bath ratio is 1:20, heat to 60℃, add Disperse Blue 2BLN at a uniform feed rate of 0.14g / L, and feed for 10min.

[0055] S2: Heat to 80℃ at a rate of 0.8℃ / min, add cationic red X-GRL at a constant rate of 0.19 g / L for 10 min, hold for 5 min, then heat to 100℃ at a rate of 0.7℃ / min, and then heat to 1250℃ at a rate of 0.8℃ / min for 20 min.

[0056] S3: Cool to 90℃ at a rate of 1.5℃ / min, add sodium sulfate at a dosage of 2g / L, stir evenly for 5min, then add blended yellow D-3RNL at a uniform feeding rate of 0.5g / L for 10min, keep warm for 30min, cool to 70℃, wash with water, and dry.

[0057] S4: The fixing polymer and nickel nitrate prepared in this example are added to water at 90°C at a mass ratio of 1:0.25, with the total addition amount controlled at 30 g / L. The mixture is then evenly dispersed to obtain a fixing solution. The fabric after step S3 is subjected to two dips and two pads using the fixing solution, with the temperature of the fixing solution controlled at 85±5°C. After padding, the fabric has a padding rate of 70%. It is then naturally cooled to room temperature (26°C) and left to stand for 12 hours. Afterward, it is washed and dried to obtain the dyed fabric.

[0058] Example 4 The steps for preparing the color-fixing polymer are as follows: (1) Pentaerythritol, ethylene oxide, and sodium formate were prepared according to a molar ratio of 1:8:0.01. Pentaerythritol and sodium formate were added to the polymerization reactor and stirred until homogeneous. The air in the polymerization reactor was replaced with nitrogen three times, and the temperature was raised to 155°C. The nitrogen pressure was adjusted to 0.2 MPa. The temperature inside the polymerization reactor was maintained at 155±5°C. Ethylene oxide was introduced into the polymerization reactor and stirred until the gas pressure no longer decreased. Then, the mixture was dried under vacuum to obtain pentaerythritol polyoxyethylene ether.

[0059] (2) According to the molar ratio of 1:8:0.5:0.16, pentaerythritol polyoxyethylene ether, isophorone diisocyanate, 2,2':6',2”-terpyridine-4'-methanol and sodium bisulfite were taken. Pentaerythritol polyoxyethylene ether and isophorone diisocyanate were added to the reaction vessel and stirred evenly. The air in the reaction vessel was replaced with nitrogen three times to maintain the temperature in the reaction vessel at 85±5℃. The reaction was stirred for 1h. Then 2,2':6',2”-terpyridine-4'-methanol was added and the temperature in the reaction vessel was maintained at 85±5℃. The reaction was stirred for another 1h. Sodium bisulfite was added to block the isocyanate groups to obtain the fixed polymer.

[0060] For polyester / cationically modified polyester / cotton blended fabrics, a three-color one-bath dyeing process is performed, as follows: S1: Pour water into the dyeing container, immerse the fabric in the water, the bath ratio is 1:20, heat to 60℃, add Disperse Blue 2BLN at a uniform feed rate of 0.14g / L, and feed for 10min.

[0061] S2: Heat to 80℃ at a rate of 0.8℃ / min, add cationic red X-GRL at a constant rate of 0.19 g / L for 10 min, hold for 5 min, then heat to 100℃ at a rate of 0.7℃ / min, and then heat to 1250℃ at a rate of 0.8℃ / min for 20 min.

[0062] S3: Cool to 90℃ at a rate of 1.5℃ / min, add sodium sulfate at a dosage of 2g / L, stir evenly for 5min, then add blended yellow D-3RNL at a uniform feeding rate of 0.5g / L for 10min, keep warm for 30min, cool to 70℃, wash with water, and dry.

[0063] S4: Take the color-fixing polymer and nickel nitrate prepared in this example at a mass ratio of 1:0.10, add them to water at 80°C, and control the total addition amount of both in the water to be 50 g / L. Disperse them evenly to obtain a color-fixing solution. Use the color-fixing solution to perform two dips and two pads on the fabric after step S3, controlling the temperature of the color-fixing solution at 85±5°C during the process. After the dips and pads are completed, the padding rate of the fabric is 70%. Allow it to cool naturally to room temperature (23°C), let it stand for 10 hours, then wash it with water and dry it to obtain the dyed fabric.

[0064] Comparative Example 1 For polyester / cationically modified polyester / cotton blended fabrics, a three-color one-bath dyeing process is performed, as follows: S1: Pour water into the dyeing container, immerse the fabric in the water, the bath ratio is 1:20, heat to 60℃, add Disperse Blue 2BLN at a uniform feed rate of 0.14g / L, and feed for 10min.

[0065] S2: Heat to 80℃ at a rate of 0.8℃ / min, add cationic red X-GRL at a constant rate of 0.19 g / L for 10 min, hold for 5 min, then heat to 100℃ at a rate of 0.7℃ / min, and then heat to 1250℃ at a rate of 0.8℃ / min for 20 min.

[0066] S3: Cool to 90℃ at a rate of 1.5℃ / min, add sodium sulfate at a dosage of 2g / L, stir evenly for 5min, then add blended yellow D-3RNL at a uniform feeding rate of 0.5g / L for 10min, keep warm for 30min, cool to 70℃, wash with water, and dry.

[0067] S4: Add polymetallic acetate SLA to water at a dosage of 30 g / L, and disperse evenly to obtain a fixing solution. Use the fixing solution to perform two dips and two nips on the fabric after step S3. After the dips and nips, the fabric has a nip rate of 70%. Heat to 85°C, keep warm for 30 min, cool naturally to room temperature (26°C), wash with water, and dry to obtain the dyed fabric.

[0068] Comparative Example 2 The steps for preparing the color-fixing polymer are as follows: (1) Pentaerythritol, ethylene oxide, and sodium formate were prepared according to a molar ratio of 1:25:0.02. Pentaerythritol and sodium formate were added to the polymerization reactor and stirred until homogeneous. The air in the polymerization reactor was replaced with nitrogen three times, and the temperature was raised to 155°C. The nitrogen pressure was adjusted to 0.1 MPa. The temperature inside the polymerization reactor was maintained at 155±5°C. Two-fifths of the ethylene oxide was introduced into the polymerization reactor, and the reaction was stirred until the pressure no longer decreased. Then, low-boiling substances were removed under vacuum. The temperature inside the polymerization reactor was maintained at 155±5°C again, and the remaining ethylene oxide was introduced. The reaction was stirred until the pressure no longer decreased. Then, the product was dried under vacuum to obtain pentaerythritol polyoxyethylene ether.

[0069] (2) Take pentaerythritol polyoxyethylene ether, isophorone diisocyanate and sodium bisulfite according to a molar ratio of 1:6:0.12. Add pentaerythritol polyoxyethylene ether and isophorone diisocyanate to the reaction vessel, stir evenly, replace the air in the reaction vessel with nitrogen three times, maintain the temperature in the reaction vessel at 85±5℃, stir and react for 2h, add sodium bisulfite to block the isocyanate groups, and obtain the fixed polymer.

[0070] For polyester / cationically modified polyester / cotton blended fabrics, a three-color one-bath dyeing process is performed, as follows: S1: Pour water into the dyeing container, immerse the fabric in the water, the bath ratio is 1:20, heat to 60℃, add Disperse Blue 2BLN at a uniform feed rate of 0.14g / L, and feed for 10min.

[0071] S2: Heat to 80℃ at a rate of 0.8℃ / min, add cationic red X-GRL at a constant rate of 0.19 g / L for 10 min, hold for 5 min, then heat to 100℃ at a rate of 0.7℃ / min, and then heat to 1250℃ at a rate of 0.8℃ / min for 20 min.

[0072] S3: Cool to 90℃ at a rate of 1.5℃ / min, add sodium sulfate at a dosage of 2g / L, stir evenly for 5min, then add blended yellow D-3RNL at a uniform feeding rate of 0.5g / L for 10min, keep warm for 30min, cool to 70℃, wash with water, and dry.

[0073] S4: Take the color-fixing polymer and nickel nitrate prepared in this example at a mass ratio of 1:0.15, add them to water at 85°C, and control the total addition amount of both in the water to be 40 g / L. Disperse them evenly to obtain a color-fixing solution. Use the color-fixing solution to perform two dips and two pads on the fabric after step S3, controlling the temperature of the color-fixing solution at 85±5°C during the process. After the dips and pads are completed, the padding rate of the fabric is 70%. Allow it to cool naturally to room temperature (24°C), let it stand for 12 hours, then wash it with water and dry it to obtain the dyed fabric.

[0074] Comparative Example 3 The steps for preparing the color-fixing polymer are as follows: (1) Pentaerythritol, ethylene oxide, and sodium formate were prepared according to a molar ratio of 1:25:0.02. Pentaerythritol and sodium formate were added to the polymerization reactor and stirred until homogeneous. The air in the polymerization reactor was replaced with nitrogen three times, and the temperature was raised to 155°C. The nitrogen pressure was adjusted to 0.1 MPa. The temperature inside the polymerization reactor was maintained at 155±5°C. Two-fifths of the ethylene oxide was introduced into the polymerization reactor, and the reaction was stirred until the pressure no longer decreased. Then, low-boiling substances were removed under vacuum. The temperature inside the polymerization reactor was maintained at 155±5°C again, and the remaining ethylene oxide was introduced. The reaction was stirred until the pressure no longer decreased. Then, the product was dried under vacuum to obtain pentaerythritol polyoxyethylene ether.

[0075] (2) According to the molar ratio of 1:6:0.3:0.12, pentaerythritol polyoxyethylene ether, isophorone diisocyanate, 2,2':6',2”-terpyridine-4'-methanol and sodium bisulfite were taken. Pentaerythritol polyoxyethylene ether and isophorone diisocyanate were added to the reaction vessel and stirred evenly. The air in the reaction vessel was replaced with nitrogen three times to maintain the temperature in the reaction vessel at 85±5℃. The reaction was stirred for 1.5h. Then 2,2':6',2”-terpyridine-4'-methanol was added and the temperature in the reaction vessel was maintained at 85±5℃. The reaction was stirred for another 0.5h. Sodium bisulfite was added to block the isocyanate groups to obtain the fixed polymer.

[0076] For polyester / cationically modified polyester / cotton blended fabrics, a three-color one-bath dyeing process is performed, as follows: S1: Pour water into the dyeing container, immerse the fabric in the water, the bath ratio is 1:20, heat to 60℃, add Disperse Blue 2BLN at a uniform feed rate of 0.14g / L, and feed for 10min.

[0077] S2: Heat to 80℃ at a rate of 0.8℃ / min, add cationic red X-GRL at a constant rate of 0.19 g / L for 10 min, hold for 5 min, then heat to 100℃ at a rate of 0.7℃ / min, and then heat to 1250℃ at a rate of 0.8℃ / min for 20 min.

[0078] S3: Cool to 90℃ at a rate of 1.5℃ / min, add sodium sulfate at a dosage of 2g / L, stir evenly for 5min, then add blended yellow D-3RNL at a uniform feeding rate of 0.5g / L for 10min, keep warm for 30min, cool to 70℃, wash with water, and dry.

[0079] S4: Take the color-fixing polymer and nickel nitrate prepared in this comparative example at a mass ratio of 1:0.15, add them to room temperature water, and control the total addition amount of both in the water to be 40 g / L. After dispersing evenly, obtain the color-fixing solution. Use the color-fixing solution to perform two dips and two nips on the fabric after step S3. After the dips and nips are completed, the fabric has a nip-out rate of 70%. Heat to 85℃, keep warm for 30 min, and place at room temperature (24℃) for 12 h. Then wash with water and dry to obtain the dyed fabric.

[0080] Test case The dyed fabrics obtained in Examples 1-4 and Comparative Examples 1-3 were tested for light fastness (GB / T 8427-2019), soap fastness (GB / T 3921-2008 Test Method A), and rubbing fastness (GB / T 3920-2008). The results are shown in Table 1.

[0081] Table 1. Color fastness test results

[0082] Analyzing the color fastness test results in Table 1, we can see that: (1) Compared with conventional color-fixing agents such as polymetallic acetate SLA (Comparative Example 1), the color fastness of dyed fabrics is significantly improved when using the color-fixing agent of the present invention (Example 3) and in conjunction with the corresponding color-fixing process. This is because the color-fixing agent of the present invention can connect dye molecules to fabric fibers in multiple ways, including the formation of physical entanglement between the color-fixing polymer and the fiber, and the interaction between the terpyridine groups on the color-fixing polymer and the dye, the groups on the fiber, and Ni… 2+ By forming coordination bonds, the isocyanate groups in the color-fixing polymer react with the hydroxyl and amino groups on the dye and fiber to form covalent crosslinks, thus achieving a good color-fixing effect on disperse dyes, cationic dyes and blended dyes.

[0083] (2) Compared to Comparative Example 2, the color-fixing polymer in Example 1 contains terpyridine groups, resulting in higher color fastness of the dyed fabric. This is because the terpyridine groups can react with Ni... 2+ Coordination bonds are formed, and dyes and fabric fibers also contain substances that can interact with Ni. 2+ Coordinating groups, therefore, via Ni 2+ It can form bridges between the fixing polymer and the dye, and between the fixing polymer and the fabric fibers, thereby making the dye molecules more firmly bound to the fabric.

[0084] (3) Compared to heating after padding (Comparative Example 3), Example 1 used water at 85°C when preparing the fixing solution and controlled the temperature of the fixing solution at 85±5°C during padding, resulting in higher color fastness of the dyed fabric. The reason is that in Comparative Example 3, the terpyridine group reacts with Ni...2+ Coordination bonds will form prematurely in the fixing solution, which is detrimental to Ni after padding. 2+ The formation of bridges between the terpyridine groups and the fabric fibers and dyes is also detrimental to the polymer encapsulating onto the fabric fibers and forming physical entanglement with them; however, in Example 1, in the fixing solution at 80-90°C, the terpyridine groups and Ni 2+ The coordination bonds between the fibers are in a dissociated state, and the terpyridine groups are not bonded together. This facilitates the coating of the fixative polymer onto the fabric fibers and the formation of physical entanglement during impregnation onto the fabric surface. Cooling after impregnation allows the terpyridine groups to interact with the Ni... 2+ Coordination bonds are formed between them, which facilitates the bonding between the fixing polymer and the fabric fibers and dyes via Ni. 2+ The connection between the two elements improves the colorfastness.

[0085] (4) Compared with Example 4, in Example 2, the polyether chain in the pentaerythritol polyoxyethylene ether used to prepare the color-fixing polymer was longer, resulting in higher color fastness of the dyed fabric. The reason is that the longer polyether chain in the pentaerythritol polyoxyethylene ether can introduce longer flexible segments into the color-fixing polymer, which is beneficial for the color-fixing polymer molecular chain to form physical entanglement with the fabric fiber, thus improving the color-fixing effect.

[0086] Unless otherwise specified, the raw materials and equipment used in this invention are all commonly used in the field; unless otherwise specified, the methods used in this invention are all conventional methods in the field.

[0087] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications, alterations, and equivalent transformations made to the above embodiments based on the technical essence of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A three-color one-bath staining method, characterized in that, Includes the following steps: S1: Pour water into the dyeing container, immerse the fabric in the water, and dye it using disperse dyes, cationic dyes, and blended dyes; S2: Mix the color-fixing agent with water at 80~90℃ to make a color-fixing solution; maintain the temperature of the color-fixing solution at 80~90℃ and impregnate the fabric after step S1; after impregnation, cool down to 20~30℃ and leave for 10~12 hours. In step S2, the fixing agent includes a soluble divalent nickel salt and a fixing polymer. The preparation steps of the fixing polymer include: mixing pentaerythritol polyoxyethylene ether and diisocyanate, reacting them at 80-90°C for 1-2 hours under inert gas protection, adding 2,2':6',2”-terpyridine-4'-methanol, and continuing to react at 80-90°C for 0.5-1 hours to obtain the fixing polymer; the molar ratio of pentaerythritol polyoxyethylene ether, diisocyanate, and 2,2':6',2”-terpyridine-4'-methanol is 1:6-8:0.1-0.5, and the pentaerythritol polyoxyethylene ether is polymerized from pentaerythritol and ethylene oxide in a molar ratio of 1:24-28.

2. The three-color one-bath staining method as described in claim 1, characterized in that, Step S1 specifically includes the following steps: S1.1: Pour water into the dyeing container, immerse the fabric in the water, heat to 50~60℃, and add disperse dye; S1.2: Heat to 75~85℃, add cationic dye, keep warm for 5~10 min, then heat to 120~130℃ and keep warm for 15~20 min; S1.3: Cool to 85~95℃, add dyeing auxiliaries, mix well, then add blended dyes, keep warm for 20~40 minutes, cool down and wash with water, and dry.

3. The three-color one-bath staining method as described in claim 1, characterized in that, The preparation method of the pentaerythritol polyoxyethylene ether includes the following steps: taking pentaerythritol and ethylene oxide in a molar ratio of 1:24~28; adding pentaerythritol and catalyst into a reaction vessel, mixing well, replacing the air in the reaction vessel with an inert gas, raising the temperature to 150~160℃, and adjusting the inert gas pressure to 0.1~0.2MPa; maintaining the temperature at 150~160℃, introducing the first part of ethylene oxide into the reaction vessel, reacting until the gas pressure no longer decreases, and dehydrating; then maintaining the temperature at 150~160℃, introducing the second part of ethylene oxide, reacting until the gas pressure no longer decreases, and dehydrating to obtain pentaerythritol polyoxyethylene ether.

4. The three-color one-bath staining method as described in claim 3, characterized in that, The molar ratio of the first portion of ethylene oxide to the second portion of ethylene oxide is 1:1.3~2.

0.

5. The three-color one-bath staining method as described in claim 2, characterized in that, In steps S1.1 to S1.3, the disperse dye, cationic dye and blended dye are added by uniform feeding, and the feeding time is 8 to 13 minutes.

6. The three-color one-bath staining method as described in claim 2, characterized in that, In step S1.3, the dyeing auxiliary agent is sodium sulfate, and the dosage is 2~10g / L.

7. The three-color one-bath staining method as described in claim 2, characterized in that: In step S1.2, during the process of heating to 75~85℃, the heating rate is 0.5~1℃ / min; In step S1.2, the specific process of heating to 120~130℃ includes the following steps: heating to 90~100℃ at a rate of 0.6~0.9℃ / min, and then heating to 120~130℃ at a rate of 0.8~1.2℃ / min.

8. The three-color one-bath staining method as described in claim 2, characterized in that, In step S1.3, during the process of cooling down to 85~95℃, the cooling rate is 1.0~1.8℃ / min.

9. The three-color one-bath staining method as described in claim 1, characterized in that, In step S2, the mass ratio of the fixing polymer to the soluble divalent nickel salt in the fixing agent is 1:0.10~0.

25.

10. The three-color one-bath staining method as described in claim 1 or 9, characterized in that, In step S2, the content of the fixing agent in the fixing solution is 30~50g / L.

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