Azo dye for PET (polyethylene terephthalate) superfine fiber PU (polyurethane) resin suede fabric as well as preparation method and deep dyeing method of azo dye

Abstract

The invention belongs to the technical field of fabric dyeing, and provides an azo dye for a PET superfine fiber PU resin suede fabric, and a preparation method and a deep dyeing method thereof. The method comprises the following steps: preparing a diazonium salt solution from a diazonium component, dissolving a coupling component in water and hydrochloric acid or concentrated sulfuric acid, and cooling in an ice bath to obtain a cooling liquid; dropwise adding the diazonium salt solution into the cooling liquid, keeping the ice bath reaction after dropwise adding, removing the ice bath, and continuing the reaction to obtain the azo dye. According to the azo dye molecular structure model, hydroxyl groups are contained at the molecular ends, a large number of hydrogen bonds can be formed among the azo dye molecular structure model, PET superfine fibers and PU resin besides intermolecular force, the molecular structure is monoazo disperse dye, the structure is simple, the size is small, a fiber amorphous area can contain a large number of dye molecules, and the dye molecules can be used for dyeing the PET superfine fibers and the PU resin. The adsorption saturation value is high, the bonding capability is strong, and ideal deep dyeing property, rubbing fastness and thermal migration resistance are endowed.

Description

Technical Field

[0001] The invention relates to the technical field of fabric dyeing, and in particular to an azo dye for PET ultrafine fiber PU resin suede-like fabric, a preparation method thereof and a deep dyeing method thereof. Background Art

[0002] PET ultrafine fiber PU resin suede-like fabric is a composite of polyester (PET) ultrafine fiber layer impregnated with polyurethane (PU) resin. It has certain air permeability and moisture permeability. Its appearance and performance are very similar to or even better than natural leather. It is now widely used in high-end shoes, clothing, furniture, balls, and car interiors. This type of suede-like fabric is generally dyed with disperse dyes. Due to the large specific surface area of ​​its ultrafine fibers and the differences in the structural properties of the two components of PET and PU, the dyeing depth of suede-like fabric has become a technical problem in the current dyeing and processing of such products, and has attracted much attention from industry insiders.

[0003] PET ultrafine fibers have a large specific surface area and reflect strong light. Compared with conventional PET fibers, to achieve a similar color depth, more dyes need to be adsorbed. Dyeing depth has become a technical problem in PET ultrafine fiber dyeing. Different dye molecular structures have different forces, adsorption positions and arrangements with fiber macromolecules. Therefore, for dye molecules with different structures, their saturated adsorption amounts are also different. In order to meet the technical requirements for dyeing depth, dye varieties with large saturated adsorption amounts and good lifting properties should be selected.

[0004] Therefore, it is of great significance to study and obtain a dye for PET ultrafine fiber PU resin suede-like fabrics and a dyeing method for improving dyeing depth, friction fastness and heat migration resistance. Summary of the invention

[0005] The purpose of the present invention is to provide an azo dye for PET ultrafine fiber PU resin suede-like fabric and a preparation method and a deep dyeing method thereof in order to overcome the deficiencies of the prior art.

[0006] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions: The present invention provides an azo dye for PET ultrafine fiber PU resin suede-like fabric, the structural formula of the azo dye is: ; Wherein, R is H, CH3 or OCH3, and X is H or CN; The structural formula of Ar is: , , or ; R1 and R2 are independently H, Cl, Br, CN or NO2.

[0007] The present invention also provides a method for preparing an azo dye for PET ultrafine fiber PU resin suede-like fabric, comprising the following steps: 1) Preparation of diazonium salt solution: Method 1: Dissolve the diazo component in water and concentrated hydrochloric acid and cool to obtain a diazo solution, add an aqueous solution of sodium nitrite dropwise to the diazo solution, continue the reaction and quench the sodium nitrite to obtain a diazonium salt solution; The diazo component is p-nitroaniline or o-chloro-p-nitroaniline; Method 2: Add the diazo component dropwise into concentrated sulfuric acid to dissolve it and then cool it, then add nitrosyl sulfuric acid dropwise into the coolant to continue the reaction to obtain a diazonium salt solution; The structural formula of the diazo component is: , the structural formula of the diazonium salt is: ; Among them, the structural formula of Ar is: , , or ; R1 and R2 are independently Br, CN or NO2; 2) Preparation of azo dyes: The coupling component is dissolved in water and acid and then cooled in an ice bath to obtain a cooling liquid; the diazonium salt solution is added dropwise to the cooling liquid, and after the addition is completed, the reaction is maintained in an ice bath, and then the ice bath is removed to continue the reaction to obtain an azo dye; The structural formula of the coupling component is: ; Wherein, R is H, CH3 or OCH3, and X is H or CN.

[0008] Preferably, in the method 1 of step 1), the molar volume ratio of the diazo component, water and concentrated hydrochloric acid is 10 mmol:10-15 mL:4-6 mL; the molar ratio of sodium nitrite to the diazo component is 10-11 mol:10 mmol.

[0009] Preferably, in method 1 of step 1), the dissolving temperature is 60-80°C, the cooling temperature is 0-5°C; the continuing reaction temperature is 0-5°C, the continuing reaction time is 1.5-2.5h, and the quenching reagent is aminosulfonic acid.

[0010] Preferably, in the method 2 of step 1), the molar volume ratio of the diazo component to concentrated sulfuric acid is 10 mmol:4-6 mL; the molar volume ratio of the diazo component to nitrosyl sulfuric acid is 10 mmol:2-2.5 mL.

[0011] Preferably, in the method 2 of step 1), the cooling temperature is 0-5°C, the temperature for continuing the reaction is 0-5°C, and the time for continuing the reaction is 1.5-2.5h.

[0012] Preferably, in step 2), the molar volume ratio of the coupling component, water and acid is 10-10.3 mmol:40-60 mL:2-5 mL; the acid is hydrochloric acid or concentrated sulfuric acid; The ice bath cooling temperature is 0-10° C., the ice bath reaction time is 1.5-2.5 h, and the ice bath is removed and the reaction time is 2-4 h.

[0013] The invention also provides a method for deep dyeing of azo dyes for PET ultrafine fiber PU resin suede-like fabrics, which comprises mixing azo dyes, auxiliary agents and water and adding the mixture into fabrics for dyeing.

[0014] Preferably, the initial dyeing temperature is 65-75°C, the dyeing temperature is 125-135°C, the dyeing time is 30-60 min, and the rate of heating to the dyeing temperature is 1-3°C / min.

[0015] The beneficial effects of the present invention include the following: 1) Based on the same chromophore, the present invention synthesizes a series of disperse dyes containing different characteristic groups, which are respectively applied to the dyeing of PET fiber and PU fiber. Through the test of adsorption isotherm and the analysis of adsorption parameter performance, the structure-activity relationship between the characteristic groups and the dyeing performance of the two types of fibers is revealed, and the structural model of the disperse dye is optimized to be suitable for the dyeing of PET ultrafine fiber PU resin suede fabric, so as to obtain a more ideal dyeing depth, and have better friction fastness and heat migration resistance.

[0016] 2) The molecular structure model of the azo dye of the present invention contains hydroxyl groups (-OH) at the molecular ends, which can form a large number of hydrogen bonds with the PET ultrafine fiber and the PU resin in addition to the intermolecular forces. Its molecular structure is a monoazo disperse dye, which has a relatively simple structure and a small volume, so that the amorphous region of the fiber can accommodate a large number of dye molecules, has a high adsorption saturation value, and has a strong bonding ability, giving it ideal dyeing depth, friction fastness and heat migration resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is the infrared spectrum of the azo dye of Example 1; Figure 2 is the infrared spectrum of the azo dye of Comparative Example 1; Figure 3 is the infrared spectrum of the azo dye of Comparative Example 2; Figure 4is the infrared spectrum of the azo dye of Comparative Example 3; Figure 5 is the infrared spectrum of the azo dye of Comparative Example 4; Figure 6 is the adsorption isotherm of the azo dyes of Example 1 and Comparative Examples 1 to 4 on PET fabric, wherein D1 is Comparative Example 1, D2 is Comparative Example 2, D3 is Comparative Example 3, D4 is Comparative Example 4, and D5 is Example 1; Figure 7 is the adsorption isotherm of the azo dyes of Example 1 and Comparative Examples 1 to 4 on PU fiber dyeing, wherein D1 is Comparative Example 1, D2 is Comparative Example 2, D3 is Comparative Example 3, D4 is Comparative Example 4, and D5 is Example 1; Figure 8 The performance improvement of the azo dyes of Example 1 and Comparative Examples 1 to 4 on dyeing suede-like fabrics, D1 is Comparative Example 1, D2 is Comparative Example 2, D3 is Comparative Example 3, D4 is Comparative Example 4, and D5 is Example 1; Fig. 9 is the infrared spectrum of Disperse Orange A of Example 2; Fig.10 is the infrared spectrum of Disperse Blue A of Example 3; Fig.11 This is a graph showing the improvement in dyeing performance of suede-like fabrics using hydroxyl-containing dyes of Examples 2 and 3. DETAILED DESCRIPTION

[0018] The present invention provides an azo dye for PET ultrafine fiber PU resin suede-like fabric, the structural formula of the azo dye is: ; Wherein, R is H, CH3 or OCH3, and X is H or CN; The structural formula of Ar is: , , or ; R1 and R2 are independently H, Cl, Br, CN or NO2.

[0019] The present invention also provides a method for preparing an azo dye for PET ultrafine fiber PU resin suede-like fabric, comprising the following steps: 1) Preparation of diazonium salt solution: Method 1: Dissolve the diazo component in water and concentrated hydrochloric acid and cool to obtain a diazo solution, add an aqueous solution of sodium nitrite dropwise to the diazo solution, continue the reaction and quench the sodium nitrite to obtain a diazonium salt solution; The diazo component is p-nitroaniline or o-chloro-p-nitroaniline; Method 2: Add the diazo component dropwise into concentrated sulfuric acid to dissolve it and then cool it, then add nitrosyl sulfuric acid dropwise into the coolant to continue the reaction to obtain a diazonium salt solution; The structural formula of the diazo component is: , the structural formula of the diazonium salt is: ; Among them, the structural formula of Ar is: , , or ; R1 and R2 are independently Br, CN or NO2; 2) Preparation of azo dyes: The coupling component is dissolved in water and acid and then cooled in an ice bath to obtain a cooling liquid; the diazonium salt solution is added dropwise to the cooling liquid, and after the addition is completed, the reaction is maintained in an ice bath, and then the ice bath is removed to continue the reaction to obtain an azo dye; The structural formula of the coupling component is: ; Wherein, R is H, CH3 or OCH3, and X is H or CN.

[0020] In method 1 of step 1) of the present invention, the molar volume ratio of the diazo component, water and concentrated hydrochloric acid is preferably 10mmol:10~15mL:4~6mL, more preferably 10mmol:11~14mL:4.5~5.5mL, more preferably 10mmol:12~13mL:5mL; the molar ratio of sodium nitrite to the diazo component is preferably 10~11mol:10mmol, more preferably 10.5mol:10mmol.

[0021] In method 1 of step 1) of the present invention, the dissolution temperature is preferably 60-80°C, more preferably 65-75°C, and the cooling temperature is preferably 0-5°C; after the diazo component is dissolved, the temperature is reduced to 0-5°C, and the reaction is continued for 1.5-2.5h, more preferably 2h; the reaction progress is preferably tracked by an amino reagent, and the quenching reagent is preferably aminosulfonic acid.

[0022] In the method 2 of step 1) of the present invention, the molar volume ratio of the diazo component to concentrated sulfuric acid is preferably 10 mmol: 4-6 mL, more preferably 10 mmol: 5 mL; the molar volume ratio of the diazo component to nitrosyl sulfuric acid is 10 mmol: 2-2.5 mL, more preferably 10 mmol: 2.2-2.3 mL.

[0023] In the method 2 of step 1) of the present invention, the cooling temperature is preferably 0-5°C, the reaction time is preferably 1.5-2.5h, more preferably 2h; the reaction endpoint is preferably detected by the ice water method.

[0024] In the present invention, the molar volume ratio of the coupling component, water and acid in step 2) is preferably 10-10.3 mmol: 40-60 mL: 2-5 mL, more preferably 10.1-10.2 mmol: 45-55 mL: 3-4 mL, and more preferably 10.2 mmol: 50 mL: 3.5 mL; the acid is hydrochloric acid or concentrated sulfuric acid; The cooling temperature of the ice bath is preferably 0-10° C.; the reaction time in the ice bath is preferably 1.5-2.5 h, more preferably 2 h; the reaction time after removing the ice bath is preferably 2-4 h, more preferably 3 h.

[0025] The invention also provides a method for deep dyeing of azo dyes for PET ultrafine fiber PU resin suede-like fabrics, which comprises mixing azo dyes, auxiliary agents and water and adding the mixture into fabrics for dyeing.

[0026] In the present invention, the initial dyeing temperature is preferably 65-75°C, more preferably 68-72°C, more preferably 70°C, the dyeing temperature is preferably 125-135°C, more preferably 130°C; the dyeing time is preferably 30-60min, more preferably 40-50min, more preferably 45min; the rate of heating to the dyeing temperature is preferably 1-3°C / min, more preferably 1.5-2.5°C / min, more preferably 2°C / min.

[0027] In the present invention, the owf of the azo dye is preferably 0.1-10%, more preferably 6-8%; the bath ratio is preferably 5-50:1, more preferably 5-10:1.

[0028] In the present invention, the auxiliary agent preferably comprises a pH adjusting agent and a dispersant MF, the concentration of the dispersant MF is preferably 0.5-2 g / L, more preferably 1 g / L; the pH adjusting agent is preferably ammonium sulfate or acetic acid, and the pH value is adjusted to 5-6; the concentration of ammonium sulfate is preferably 0.8-1.2 g / L, more preferably 1 g / L; the concentration of acetic acid is preferably 0.8-1.2 mL / L, more preferably 1 mL / L.

[0029] In the present invention, the dyeing is followed by cooling, and the cooling temperature is preferably 75-85°C, more preferably 80°C; after cooling, the PET fiber is sequentially subjected to reduction cleaning and water cleaning, and the PU fiber is subjected to water cleaning; the reduction cleaning reagent preferably comprises sodium hypochlorite, caustic soda and water, and the concentrations of sodium hypochlorite and caustic soda are independently preferably 1.8-2.2 g / L, more preferably 2 g / L; the reduction cleaning temperature is preferably 80-90°C, more preferably 82-88°C, more preferably 84-85°C; the reduction cleaning time is preferably 12-17 min, more preferably 13-16 min, more preferably 14-15 min; the bath ratio is preferably 5-50:1, more preferably 5-10:1.

[0030] The technical solutions provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0031] Example 1 Preparation of p-nitrodiazonium salt: Add 10mmol p-nitroaniline to a 50mL three-necked bottle, add 10mL water and 5mL concentrated hydrochloric acid in sequence, start stirring, heat to 60℃ in a water bath, cool to 0~5℃ in an ice bath after dissolution, and obtain p-nitroaniline solution. Dissolve 10.5mol sodium nitrite in 3mL water, slowly drip the sodium nitrite solution into the p-nitroaniline solution, continue to react at 0~5℃ for 2h, use an amino reagent (p-dimethylaminobenzaldehyde) to track the progress of the reaction, and add aminosulfonic acid to quench the excess sodium nitrite after the reaction is completed.

[0032] Preparation of azo dyes: Add 60 mL of water, 4 mL of concentrated sulfuric acid and 3 drops of fatty alcohol polyoxyethylene ether-9 (AEO-9) to a 500 mL three-necked bottle, start stirring, add 10 mmol of coupling component and stir at room temperature until dissolved. Cool to 0-10 ° C in an ice bath, slowly drip the diazonium salt solution into the coolant, add crushed ice to the reaction system during the dropwise addition to maintain 0-10 ° C, and the dropwise addition time is 30 min. After the dropwise addition is completed, keep the ice bath for 2 hours, and continue the reaction for 4 hours after removing the ice bath. Filter and purify the azo dye by DMF-water recrystallization method.

[0033] The structural formula of 4-nitrodiazonium salt is:

[0034] The structural formulas of the coupling component and the azo dye are: , , A is OH.

[0035] Comparative Example 1 The preparation of p-nitrodiazonium salt is the same as in Example 1.

[0036] Preparation of coupling component: Add 40mL of dichloromethane as solvent to a 500mL three-necked flask, then add 0.2g of 4-dimethylaminopyridine and 2mL of triethylamine in sequence, and then add 10mmol of N-ethyl-N-hydroxyethyl-m-toluidine and 10.5mmol of p-methylbenzoyl chloride in sequence after fully dissolving. Ultrasonic oscillation (53kHz) was applied to the reaction solution in an ultrasonic cleaner for 30s at room temperature, and the reaction progress was tracked by thin layer spotting after standing for 30min. After the reaction was completed, the dichloromethane was dried at 40°C, and the coupling component was directly used for the next step of preparing azo dyes.

[0037] The structural formulas of N-ethyl-N-hydroxyethyl-m-toluidine and the coupling component are: , .

[0038] In the preparation of azo dyes, 60 mL of water, 60 mL of anhydrous ethanol, 4 mL of concentrated sulfuric acid and 3 drops of AEO-9 were added to a 500 mL three-necked bottle. The coupling components were different from those in Example 1, and the other conditions were the same as those in Example 1.

[0039] The structural formula of azo dyes is: , A is .

[0040] Comparative Example 2 The preparation of p-nitrodiazonium salt is the same as in Example 1.

[0041] The structural formula of the coupling component is:

[0042] Preparation of coupling components: 40 mL of dichloromethane was added as solvent to a 200 mL single-necked flask, followed by 10 mmol of N-ethyl-N-hydroxyethyl-m-toluidine and 10.5 mmol of p-toluene isocyanate. The reaction solution was ultrasonically oscillated (53 kHz) for 30 seconds in an ultrasonic cleaner at room temperature, and then the reaction progress was tracked by thin layer spotting after standing for 30 minutes. After the reaction was completed, the dichloromethane was dried at 40°C to obtain a white solid product with a yield of 98%.

[0043] In the preparation of azo dyes, 60 mL of water, 60 mL of anhydrous ethanol, 4 mL of concentrated sulfuric acid and 3 drops of AEO-9 were added to a 500 mL three-necked bottle. The coupling components were different from those in Example 1, and the other conditions were the same as those in Example 1.

[0044] The structural formula of azo dyes is: , A is .

[0045] Comparative Example 3 The preparation of p-nitrodiazonium salt is the same as in Example 1.

[0046] Preparation of coupling components: Add 40 mL of dichloromethane as solvent to a 500 mL three-necked flask, then add 0.2 g of 4-dimethylaminopyridine and 2 mL of triethylamine in sequence, fully dissolve and mix, then add 10 mmol of N-ethyl-N-aminoethyl-m-toluidine and 10.5 mmol of p-methylbenzoyl chloride in sequence, ultrasonically oscillate the reaction solution in an ultrasonic cleaner (53 kHz) for 30 seconds at room temperature, let it stand for 30 minutes, and then spot the reaction with a thin layer to track the reaction progress. After the reaction, spin dry the dichloromethane at 40 ° C, and the obtained coupling components are directly used for the next coupling reaction.

[0047] The structural formulas of N-ethyl-N-aminoethyl-m-toluidine and the coupling component are: , .

[0048] In the preparation of azo dyes, 60 mL of water, 60 mL of anhydrous ethanol, 4 mL of concentrated sulfuric acid and 3 drops of AEO-9 were added to a 500 mL three-necked bottle. The coupling components were different from those in Example 1, and the other conditions were the same as those in Example 1.

[0049] The structural formula of azo dyes is: , A is .

[0050] Comparative Example 4 The preparation of p-nitrodiazonium salt is the same as in Example 1.

[0051] Preparation of coupling components: 40 mL of dichloromethane was added as solvent to a 200 mL single-necked flask, followed by 10 mmol of N-ethyl-N-aminoethyl-m-toluidine and 10.5 mmol of p-toluene isocyanate. The reaction solution was ultrasonically oscillated (53 kHz) for 30 seconds in an ultrasonic cleaner at room temperature, and then the reaction progress was tracked by thin layer spotting after standing for 30 minutes. After the reaction was completed, the dichloromethane was dried at 40°C to obtain a white solid product with a yield of 98%.

[0052] The structural formula of the coupling component is: .

[0053] In the preparation of azo dyes, 60 mL of water, 60 mL of anhydrous ethanol, 4 mL of concentrated sulfuric acid and 3 drops of AEO-9 were added to a 500 mL three-necked bottle. The coupling components were different from those in Example 1, and the other conditions were the same as those in Example 1.

[0054] The structural formula of azo dyes is: , A is .

[0055] The infrared spectra of the azo dyes of Example 1 and Comparative Examples 1 to 4 are as follows: Figures 1 to 5 As shown. Figure 1 It can be seen that 3313cm -1 is the stretching vibration peak of hydroxyl (OH), 2971cm -1 is the stretching vibration peak of CH in methylene, 1596cm -1 The carbonyl (C=O) stretching vibration peak in the ester group is 1539 cm -1 The stretching vibration peak of azo group (N=N) or benzene ring (C=C) is 1503cm -1 The asymmetric stretching vibration peak of NO2 is 1423 cm -1 OH bending (in-plane) vibration peak, 1323 cm -1 is the symmetrical stretching vibration peak of NO2, 1250cm -1 CN stretching vibration peak, 1104cm -1 is the CO stretching vibration peak in the ester group. Figure 2 It can be seen that 1714cm -1 The carbonyl (C=O) stretching vibration peak in the ester group is 1593 cm -1 The peak of stretching vibration of azo group (N=N) or benzene ring (C=C) is 1508cm -1 is the asymmetric stretching vibration peak of NO2, 1321cm -1 The symmetrical stretching vibration peak of NO2 is 1253 cm -1 is the CN stretching vibration peak, 1093cm -1 is the CO stretching vibration peak in the ester group. Figure 3 It can be seen that 3315cm -1 is the (NH) stretching vibration peak in carbamate, 2969 cm -1 is the stretching vibration peak of CH in methylene, 1701cm -1 The carbonyl (C=O) stretching vibration peak in the ester group is 1599 cm -1 The peak of stretching vibration of azo group (N=N) or benzene ring (C=C) is 1514cm -1 The asymmetric stretching vibration peak of NO2 is 1327 cm -1 The symmetrical stretching vibration peak of NO2 is 1229 cm -1 is the CN stretching vibration peak, 1101cm -1 is the CO stretching vibration peak in the ester group. Figure 4 It can be seen that 3346cm -1 is the (NH) stretching vibration peak in the amide bond, 1635 cm -1 is the stretching vibration peak of the carbonyl (C=O) in the ester group, 1600cm -1 The peak of stretching vibration of azo group (N=N) or benzene ring (C=C) is 1510cm-1 The asymmetric stretching vibration peak of NO2 is 1332 cm -1 The symmetrical stretching vibration peak of NO2 is 1242 cm -1 is the CN stretching vibration peak, 1103cm -1 is the CO stretching vibration peak in the ester group. Figure 5 It can be seen that 3304cm -1 The (NH) stretching vibration peak in the amide bond, 2974 cm -1 is the stretching vibration of CH in methylene, 1631 cm -1 The carbonyl (C=O) stretching vibration peak in the ester group is 1598 cm -1 and 1566cm -1 The peak of stretching vibration of azo group (N=N) or benzene ring (C=C) is 1510cm -1 The asymmetric stretching vibration peak of NO2 is 1425 cm -1 The CN stretching vibration peak in the amide bond, 1332 cm -1 The symmetrical stretching vibration peak of NO2 is 1230 cm -1 CN stretching vibration peak, 1097cm -1 It is the CO stretching vibration peak in the ester group.

[0056] Adsorption performance test of azo dyes of Example 1 and Comparative Examples 1 to 4 on PET fiber and PU fiber: In order to understand the influence of various characteristic groups on the adsorption capacity and adsorption saturation value of PET and PU materials, the adsorption isotherms of PET fabric and PU fiber dyeing were measured respectively.

[0057] The test method is as follows: prepare dyeing solutions containing a series of azo dyes with different concentrations. In the dyeing solution, the concentration of ammonium sulfate is 1g / L, the pH value of the system is adjusted to 5, the concentration of dispersant MF (sodium methylene bismethyl naphthalene sulfonate) is 1g / L, and the bath ratio is 50:1. The dyeing machine is heated to 70℃, the PET fabric is put into the dye cup and placed in the dyeing machine, and the temperature is raised to 130℃ at a rate of 1℃ / min after running for 5min. PU fiber is dyed from room temperature and heated to 120℃ at a rate of 1℃ / min. After keeping warm for 60min to reach dyeing equilibrium, the temperature is lowered to 80℃ and the dyed sample is taken out. The PET fabric dyed sample is sequentially washed with hydrosulfite reduction and washed with cold water. In the hydrosulfite reduction washing, the hydrosulfite concentration is 2g / L, the NaOH concentration is 2g / L, the bath ratio is 50:1, the washing temperature is 85℃, the washing time is 15min, and the cold water washing is followed by natural drying; the PU fiber dyed sample is directly rinsed with cold water and then dried naturally.

[0058] Dye adsorption test: Use N,N-dimethylformamide (DMF) solvent to repeatedly strip the dye sample that is accurately weighed (±0.1mg). The stripping process is: weigh 0.0200~0.0600g of dyed fabric, put it into a 100mL beaker, add 5~10mL DMF solvent, heat it on an electric furnace, control the temperature at 130℃, and slowly extract the dye. Repeat the above operation 3 times until the dye sample becomes colorless. And make the extract volume constant, use UV-2450 spectrophotometer to test its absorbance respectively, and calculate the adsorption amount through the working curve of the dye. The equilibrium adsorption amount on the fiber [D] is respectively f ~Dye concentration in solution [D] s Plotting was performed to obtain the adsorption isotherm. The adsorption isotherms of the azo dyes for dyeing PET fabrics in Example 1 and Comparative Examples 1 to 4 are shown in FIG. Figure 6 As shown, the adsorption isotherms of the azo dyes of Example 1 and Comparative Examples 1 to 4 on PU fiber dyeing are as follows Figure 7 As shown, D1 is comparative example 1, D2 is comparative example 2, D3 is comparative example 3, D4 is comparative example 4, and D5 is embodiment 1.

[0059] pass Figures 6 and 7 It can be found from the shape that, except for the hydroxyl-containing dye of Example 1 which exhibits a composite adsorption model of Nernst and Langmuir on PET fabric, the dyes of Comparative Examples 1 to 4 are all Nernst type adsorption. This is because the dye of Example 1 contains hydroxyl groups at the molecular end, and a strong hydrogen bond localized adsorption occurs with the PET fiber. Further analysis of the data of the above adsorption isotherms can obtain adsorption performance parameters such as the distribution coefficient, affinity and saturated adsorption amount, as shown in Table 1.

[0060] Table 1 Distribution coefficient, affinity and saturated adsorption capacity of dyes on different fibers

[0061] As can be seen from Table 1, in the case of having the same chromophore, the characteristic group has a greater influence on the dyeing performance of PET fabrics and PU fibers. By comparison, it can be found that the amide-containing disperse dye in Comparative Example 3 has a greater affinity for both materials, but its saturated adsorption capacity is not ideal, especially for PET fabrics, which is at a medium level; the urea-containing disperse dye in Comparative Example 4, although it has the highest saturated adsorption capacity on PU fibers, has the lowest saturated adsorption capacity on PET fabrics, which is related to the hydrophilic tendency of the urea itself and poor affinity with hydrophobic fiber PET; the dye containing carbamate characteristic groups in Comparative Example 2, because it is similar to the characteristic groups of PU fibers, shows the highest affinity, but its saturated adsorption capacity is not ideal; The ester-containing disperse dyes of Example 1 do not have the highest affinity and saturated adsorption capacity for both materials; the hydroxyl-containing dyes of Example 1, because they easily form hydrogen bonds with water molecules, their affinity with both materials is not the largest, but their saturated adsorption capacity is relatively large, the adsorption saturation value on the PU fiber is 41.5g / kg, and the adsorption on the PET fabric belongs to the adsorption of the composite model, one part of which produces localized adsorption with the Langmuir model, and its adsorption saturation value is 11.73g / kg, and the other part of the dye is adsorbed with the Nernst model, and the adsorption capacity increases linearly with the increase of the dye concentration. When the total adsorption amount reaches 28.72g / kg, it still does not reach saturation, which is far more than the dyes of Comparative Examples 1 to 4. Based on the above test results, it is found that the hydroxyl-containing disperse dyes have a high saturated adsorption capacity for both materials, and are suitable for the dark color dyeing of PET ultrafine fiber PU resin suede fabrics.

[0062] Test on the improvement of dyeing of suede-like fabric by azo dyes of Example 1 and Comparative Examples 1 to 4: The dyeing enhancement test of suede-like fabric was carried out using azo disperse dyes containing different characteristic groups in Example 1 and Comparative Examples 1 to 4. The dyeing was carried out using the same dyeing process with the concentration of dye liquor changed. The dyeing was started at 70°C, the temperature was raised to 130°C at a rate of 1°C / min, the temperature was lowered to 80°C after keeping the temperature for 40 minutes, and the fabric was discharged. The color depth values ​​(K / S values) of the dyed samples were measured respectively, and plotted corresponding to the dye concentration (owf) to obtain the enhancement curve. The results are shown in FIG. Figure 8 As shown, D1 is comparative example 1, D2 is comparative example 2, D3 is comparative example 3, D4 is comparative example 4, and D5 is embodiment 1.

[0063] from Figure 8The data show that among the five dyes, the worst enhancing property is the urea-containing dye D4, and the color depth value (K / S value) reaches the maximum (10.19) when the dye concentration is 3% (owf); followed by the amide-containing dye D3, and the color depth value (K / S value) reaches the maximum (13.33) when the dye concentration is 3.5% (owf); the carbamate-containing dye D2 and the ester-containing dye D1 are at a medium level, and the color depth values ​​reach the highest (13.72 and 15.01) at 2% (owf) and 4% (owf), respectively; the best enhancing property is the hydroxyl-containing dye D5 of Example 1, and the color depth value reaches the highest when the dye concentration is 6% (owf), and its K / S value is 37.60, which is much higher than the highest color depth values ​​of the other four dyes. This result is basically consistent with the saturated adsorption test results of the above-mentioned PET fabric and PU fiber. The saturated adsorption capacity of hydroxyl-containing dyes on the two materials is high, and its dyeing improvement property for suede-like fabrics is also the best, which further verifies that hydroxyl-containing disperse dyes are suitable for dark dyeing of suede-like fabrics.

[0064] The rubbing fastness and color migration fastness of the suede-like fabric are important inspection objects. The color fastness of the dyed suede-like fabric samples with the highest color depth value of the azo dyes in Example 1 and Comparative Examples 1 to 4 is tested for color fastness. The test standard methods are: the color fastness to rubbing refers to the "ISO 105-X12 Textiles Color Fastness Test X12 Part: Color Fastness to Rubbing" standard, and the color migration fastness refers to the "AATCC 163-2013 Method I Color Fastness: Dye Transfer from Fabric to Fabric in Storage" standard. The results are shown in Table 2.

[0065] Table 2 Color fastness properties of disperse dyes containing different characteristic groups on suede-like dark-colored samples

[0066] From the fastness performance results in Table 2, it can be seen that Example 1 containing hydroxyl dyes has excellent rubbing fastness and color migration fastness performance, while the four dyes of Comparative Examples 1 to 4 have severe surface adsorption, and the rubbing fastness and color migration fastness are at a low level, which is not suitable for dark color dyeing of suede-like fabrics.

[0067] Example 2

[0068] Add 10mmol o-chloro-p-nitroaniline to a 50mL three-necked bottle, add 10mL water and 5mL concentrated hydrochloric acid in sequence, start stirring, heat to 80℃ in a water bath, cool to 0~5℃ in an ice bath after dissolving, and obtain o-chloro-p-nitroaniline solution. Dissolve 10.5mol sodium nitrite in 3mL water, slowly drip the sodium nitrite solution into the o-chloro-p-nitroaniline solution, continue to react at 0~5℃ for 2h, use an amino reagent (p-dimethylaminobenzaldehyde) to track the progress of the reaction, and add aminosulfonic acid to quench the excess sodium nitrite after the reaction is completed.

[0069] Add 60mL of water, 4mL of concentrated sulfuric acid and 3 drops of AEO-9 to a 500mL three-necked flask, start stirring, add 10mmol of coupling component and stir at room temperature until dissolved. Cool to 0~10℃ in an ice bath, slowly drip the diazonium salt solution into the coolant, add crushed ice to the reaction system to maintain 0~10℃ during the addition, and the addition time is 30min. After the addition is completed, keep the ice bath for 2h, remove the ice bath and continue the reaction for 2h. Filter and purify the azo dye (Disperse Orange A) by DMF-water recrystallization method.

[0070] The structural formulas of the coupling component and the azo dye are: , .

[0071] Example 3

[0072] Add 5 mL of concentrated sulfuric acid to a 50 mL three-necked bottle, start stirring, and slowly add 10 mmol of benzisothiazole to the three-necked bottle. After dissolving, cool to 0-5 ° C with an ice bath, drop 2.5 mL of nitrosyl sulfuric acid, continue to react at 0-5 ° C for 2 h, and detect the end point of the reaction by ice water method. Other conditions are the same as in Example 2 to obtain an azo dye (disperse blue A).

[0073] The structural formula of azo dyes is: .

[0074] The two dyes synthesized in Examples 2 and 3 were analyzed using an infrared spectrometer. The results are as follows: Fig. 9 , 10 As shown. Fig. 9 Analysis shows that 3363cm -1 is the stretching vibration peak of hydroxyl (OH), 3099cm -1 is the stretching vibration of benzene ring CH, 2914cm -1 is the stretching vibration of CH in methylene, 2248 cm -1 is the stretching vibration peak of cyano (CN), 1605cm -1 The peak of stretching vibration of azo group (N=N) or benzene ring (C=C) is 1512cm -1 is the asymmetric stretching vibration peak of NO2, 1400cm -1 OH bending (in-plane) vibration peak, 1364 cm -1 Symmetric stretching vibration of NO2, 1152 cm -1 CN stretching vibration, 1047cm -1 It is the stretching vibration of CO in the ester group. Fig.10 Analysis shows that 3416cm -1is the stretching vibration peak of hydroxyl (OH), 3094 cm -1 is the stretching vibration of benzene ring CH, 2935cm -1 is the stretching vibration of CH in methylene, 2246 cm -1 is the stretching vibration peak of cyano (CN), 1594 cm -1 The peak of stretching vibration of azo group (N=N) or benzene ring (C=C) is 1548cm -1 is the (C=N) stretching vibration peak in benzisothiazole, 1514 cm -1 The asymmetric stretching vibration peak of NO2 is 1398 cm -1 OH bending (in-plane) vibration peak, 1325 cm -1 The symmetrical stretching vibration peak of NO2 is 1245 cm -1 CC stretching vibration peak, 1138cm -1 CN stretching vibration peak, 1049cm -1 It is the CO stretching vibration peak in the ester group.

[0075] The dyeing performance test of the dyes of Example 2 and Example 3 on suede-like fabrics: The suede-like fabric was dyed with the two disperse dyes of Examples 2 and 3, and the lifting property, rubbing fastness and color migration fastness were measured respectively. The results are as follows: Fig.11 And as shown in Table 3.

[0076] from Fig.11 The data show that the two hydroxyl-containing dyes have good lifting properties when used for dyeing suede-like fabrics. The highest color depth values ​​are reached when the dye concentration reaches 5% (owf) and 6.5% (owf), respectively. The K / S values ​​of Disperse Orange A and Disperse Blue A are over 32 and 28, respectively. It further shows that whether it is an aromatic amine diazo component (Disperse Orange A) or a heterocyclic amine diazo component (Disperse Blue A), as long as the coupling component contains hydroxyl groups at the end, it can achieve good lifting properties when dyeing suede-like fabrics, which is suitable for dyeing suede-like fabrics in dark colors, and the friction fastness and color migration fastness are both at level 4 and above (see Table 3), which can better meet the product quality requirements of dark and dark suede-like fabrics.

[0077] Table 3 Color fastness properties of suede-like leather dyed with hydroxyl disperse dyes

[0078] The hydroxyl-containing disperse dyes of the present invention can achieve dark and rich dyeing of suede-like fabrics, have a complete color spectrum, and can meet the needs of actual production.

[0079] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. An azo dye for PET ultrafine fiber PU resin suede-like fabric, characterized in that: The structural formula of azo dyes is: ； Wherein, R is H, CH3 or OCH3, and X is H or CN; The structural formula of Ar is: , , or ; R1 and R2 are independently H, Cl, Br, CN or NO2.

2. The method for preparing the azo dye for PET ultrafine fiber PU resin suede-like fabric according to claim 1, characterized in that: The following steps are included: 1) Preparation of diazonium salt solution: Method 1: Dissolve the diazo component in water and concentrated hydrochloric acid and cool to obtain a diazo solution, add an aqueous solution of sodium nitrite dropwise to the diazo solution, continue the reaction and quench the sodium nitrite to obtain a diazonium salt solution; The diazo component is p-nitroaniline or o-chloro-p-nitroaniline; Method 2: Add the diazo component dropwise into concentrated sulfuric acid to dissolve it and then cool it, then add nitrosyl sulfuric acid dropwise into the coolant to continue the reaction to obtain a diazonium salt solution; The structural formula of the diazo component is: , the structural formula of the diazonium salt is: ; Among them, the structural formula of Ar is: , , or ; R1 and R2 are independently Br, CN or NO2; 2) Preparation of azo dyes: The coupling component is dissolved in water and acid and then cooled in an ice bath to obtain a cooling liquid; the diazonium salt solution is added dropwise to the cooling liquid, and after the addition is completed, the reaction is maintained in an ice bath, and then the ice bath is removed to continue the reaction to obtain an azo dye; The structural formula of the coupling component is: ； Wherein, R is H, CH3 or OCH3, and X is H or CN.

3. The method for preparing an azo dye for PET ultrafine fiber PU resin suede-like fabric according to claim 2, characterized in that: In method 1 of step 1), the molar volume ratio of the diazo component, water and concentrated hydrochloric acid is 10 mmol:10-15 mL:4-6 mL; the molar ratio of sodium nitrite to the diazo component is 10-11 mol:10 mmol.

4. The method for preparing an azo dye for PET ultrafine fiber PU resin suede-like fabric according to claim 2 or 3, characterized in that: In the method 1 of step 1), the dissolving temperature is 60-80°C, the cooling temperature is 0-5°C; the temperature for continuing the reaction is 0-5°C, the time for continuing the reaction is 1.5-2.5h, and the quenching reagent is aminosulfonic acid.

5. The method for preparing an azo dye for PET ultrafine fiber PU resin suede-like fabric according to claim 2, characterized in that: In the method 2 of step 1), the molar volume ratio of the diazo component to concentrated sulfuric acid is 10 mmol: 4-6 mL; the molar volume ratio of the diazo component to nitrosyl sulfuric acid is 10 mmol: 2-2.5 mL.

6. The method for preparing an azo dye for PET ultrafine fiber PU resin suede-like fabric according to claim 2 or 5, characterized in that: In the method 2 of step 1), the cooling temperature is 0-5°C, the temperature for continuing the reaction is 0-5°C, and the time for continuing the reaction is 1.5-2.5h.

7. The method for preparing an azo dye for PET ultrafine fiber PU resin suede-like fabric according to claim 2, characterized in that: Step 2) The molar volume ratio of the coupling component, water and acid is 10-10.3 mmol:40-60 mL:2-5 mL; the acid is hydrochloric acid or concentrated sulfuric acid; The ice bath cooling temperature is 0-10° C., the ice bath reaction time is 1.5-2.5 h, and the ice bath is removed and the reaction time is 2-4 h.

8. The deep dyeing method of azo dyes for PET ultrafine fiber PU resin suede-like fabrics according to claim 1, characterized in that: Mix azo dyes, auxiliaries and water and add them to fabric for dyeing.

9. The deep dyeing method according to claim 8, characterized in that: The initial dyeing temperature is 65~75℃, the dyeing temperature is 125~135℃, the dyeing time is 30~60min, and the rate of heating to the dyeing temperature is 1~3℃ / min.

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