Denim with ozone fastness resistance and preparation method thereof

Abstract

The invention relates to the technical field of textiles, in particular to denim with ozone fastness resistance and a preparation method thereof. The preparation method comprises the following steps: S1, uniformly mixing an amino-terminated hyperbranched polymer and deionized water, heating to 70-80 DEG C, dropwise adding a mixed solution of a cationic modifier and deionized water within 1-2 hours, carrying out heat preservation reaction for 3-5 hours, and carrying out precipitation separation and drying to obtain an ozone-resistant color fastness improver; s2, uniformly mixing an ozone-resistant color fastness improver and deionized water to obtain a finishing solution; s3, immersing the denim into the finishing liquid, heating to 50-60 DEG C, treating for 30-50 minutes, taking out, dehydrating, and baking for 3-5 minutes at 100-150 DEG C to obtain the denim with ozone fastness, the denim not only has excellent ozone resistance, but also has excellent ultraviolet protection effect and antibacterial effect, and the service life of the denim is prolonged.

Description

Technical Field

[0001] The invention relates to the technical field of textiles, in particular to a denim fabric with high ozone fastness resistance and a preparation method thereof. Background Art

[0002] With the acceleration of industrialization and the rapid increase in the number of cars in cities, the amount of ozone in the air has increased significantly, even reaching a level that is harmful to health and the environment. Ozone not only poses a threat to the human respiratory system, but also has a significant impact on many materials, especially textiles such as denim.

[0003] The ozone fastness of denim refers to its ability to maintain color stability after exposure to ozone. Ozone (O3) in the atmosphere is a very strong oxidant. Under the irradiation of (UV) ultraviolet light, it will decompose the dye and cause discoloration. The indigo dye used for dyeing denim fabrics has the characteristic of being resistant to oxidation and turning yellow. Indigo will decompose into indigo (2,3-dihydroindoledione), tannic acid and a combination of the two under the action of ozone, causing the fabric to turn yellow. Not only does it change the color of the denim, but it also damages the appearance of the fabric, seriously affecting the quality and service life of the clothing.

[0004] Therefore, we propose a denim fabric with ozone fastness resistance and a preparation method thereof. Summary of the invention

[0005] The object of the present invention is to provide a denim fabric with high ozone fastness and a preparation method thereof, so as to solve the problems raised in the prior art.

[0006] To achieve the above object, the present invention provides the following technical solutions: A method for preparing denim fabric with high ozone fastness comprises the following steps: Step S1: uniformly mix the amino-terminated hyperbranched polymer and deionized water, raise the temperature to 70-80° C., dropwise add a mixed solution of a cationic modifier and deionized water, and complete the dropwise addition for 1-2 hours. Keep the temperature for reaction for 3-5 hours, and obtain an ozone fastness enhancer after precipitation, separation, and drying. Step S2: uniformly mixing the ozone fastness enhancer and deionized water to obtain a finishing solution; Step S3: immerse the denim in the finishing liquid, heat it to 50-60° C. for 30-50 minutes, take it out, dehydrate it, and bake it at 100-150° C. for 3-5 minutes to obtain the denim with ozone fastness.

[0007] Furthermore, in step S1, the mass ratio of the amino-terminated hyperbranched polymer to deionized water is 1:(20-50).

[0008] Furthermore, in step S1, the mass of the cationic modifier is 0.1-1.0 times the mass of the amino-terminated hyperbranched polymer, and the mass ratio of the cationic modifier to deionized water is 1:(8-10).

[0009] Furthermore, in step S2, the concentration of the ozone fastness enhancer in the finishing liquid is 10-20 g / L.

[0010] Furthermore, in step S3, the bath ratio of the denim fabric to the finishing liquid is 1:(30-50).

[0011] Furthermore, the preparation method of the amino-terminated hyperbranched polymer is as follows: Diethylenetriamine, hexamethylenediamine and methanol are mixed evenly, methyl acrylate is added dropwise over 1-2 hours, the mixture is reacted at 40-50°C for 12-24 hours, the temperature is increased to 140-160°C at a heating rate of 20°C / h, and the reaction is performed for 2-4 hours to obtain an amino-terminated hyperbranched polymer.

[0012] Furthermore, the amino-terminated hyperbranched polymer comprises the following components by weight: 12-14 parts of diethylenetriamine, 125-138 parts of hexamethylenediamine, 45-50 parts of methanol, and 85-95 parts of methyl acrylate.

[0013] Furthermore, the preparation method of the cationic modifier is as follows: Step (1): uniformly mixing amino silicone oil, epoxidized ultraviolet absorber and anhydrous ethanol, reacting at 20-30° C. for 6-8 hours, and distilling under reduced pressure to obtain modified amino silicone oil; Step (2): uniformly mix the modified amino silicone oil and anhydrous ethanol, add sodium ethoxide, and react for 30-40 minutes in an ice bath to obtain solution A; uniformly mix N,N-dimethyl-2-chloroethylamine hydrochloride and anhydrous ethanol, add sodium ethoxide, and react for 30-40 minutes in an ice bath to obtain solution B; uniformly mix solution A and solution B, react at 50-60° C. for 12-24 hours, filter, and distill under reduced pressure to obtain a tertiary amine compound; Step (3): Evenly mix the tertiary amine compound and deionized water, adjust the system pH to 7.0-7.5 with concentrated sulfuric acid, raise the temperature to 70-80°C, drop epichlorohydrin, add the dropwise addition over 0.5-1.0h, react for 8-10h, and obtain a cationic modifier.

[0014] In the above technical scheme, the amino group in the amino silicone oil undergoes a ring-opening reaction with the epoxidized ultraviolet absorber to form a secondary amino structure; then, it reacts with N,N-dimethyl-2-chloroethylamine hydrochloride and sodium ethoxide to generate N,N-dimethylchloroethylamine to generate a tertiary amine compound; finally, the tertiary amine group of the tertiary amine compound undergoes a quaternization reaction with the -Cl of epichlorohydrin to obtain a cationic modifier; the active epoxy group on the cationic modifier can further react with the terminal amino hyperbranched polymer to obtain an ozone fastness enhancer.

[0015] Furthermore, in the step (1), the mass ratio of amino silicone oil, epoxidized UV absorber and anhydrous ethanol is 1:(1.2-1.5):(8-10).

[0016] Furthermore, in the step (2), the mass ratio of modified amino silicone oil, anhydrous ethanol and sodium ethoxide is 1:(8-12):(0.1-0.2).

[0017] Furthermore, in step (2), the mass ratio of N,N-dimethyl-2-chloroethylamine hydrochloride, anhydrous ethanol and sodium ethoxide is 1:(8-12):(0.5-0.6), and the mass of N,N-dimethyl-2-chloroethylamine hydrochloride is 0.8-1.0 of the mass of the modified amino silicone oil.

[0018] Furthermore, in step (3), the mass ratio of the tertiary amine compound, deionized water and epichlorohydrin is 1:(5-10):(0.5-1.5).

[0019] Further, the preparation method of the epoxidized ultraviolet absorber is as follows: Step A: o-nitroaniline, hydrochloric acid and deionized water are mixed, stirred at 25-30°C for 30-40 minutes, cooled to 0-5°C, sodium nitrite aqueous solution is added dropwise, the dripping is completed in 1-2 hours, and the reaction is carried out for 30-50 minutes. Urea is added to remove excess sodium nitrite until the starch-potassium iodide test paper does not turn blue, and then filtered to obtain a diazonium salt aqueous solution; Mix 2-naphthol-6-sulfonic acid sodium hydrate and deionized water evenly, adjust the system pH to 8-9 with sodium carbonate, place in an ice water bath, add diazonium salt aqueous solution dropwise, drip for 1-2 hours, react for 2-4 hours, and obtain an intermediate; Step B: The intermediate, ethanol and sodium hydroxide are mixed evenly, heated to 80-90°C, and sodium hydroxide is added every 30 minutes. The mixture is refluxed for 1-2 hours, cooled to room temperature, acidified and filtered, and the filter cake is washed and dried to obtain a UV absorber; Step C: uniformly mix the ultraviolet absorber, epichlorohydrin and tetrabutylammonium bromide, react at 80-90°C for 3-5h, cool to 50-55°C, add sodium hydroxide solution, continue to react for 2-3h, filter, wash and dry to obtain the epoxidized ultraviolet absorber.

[0020] In the above technical scheme, o-nitroaniline is diazotized and coupled with 2-naphthol-6-sulfonate sodium hydrate to generate 2-naphthol-7-sulfonate azo o-nitrobenzene intermediate, and then the intermediate is reduced with hydrosulfite to finally generate a water-soluble benzotriazole ultraviolet absorber; the ultraviolet absorber is then modified with epichlorohydrin to prepare an epoxy monomer containing ultraviolet absorbing groups, namely, an epoxidized ultraviolet absorber.

[0021] Furthermore, in step A, the mass ratio of o-nitroaniline, hydrochloric acid and deionized water is 1:(1.5-2.0):(8-10), and the concentration of hydrochloric acid is 36-38wt%.

[0022] Furthermore, in step A, the concentration of the sodium nitrite aqueous solution is 12-16wt%, and its amount is 25-35% of the mass of o-nitroaniline.

[0023] Furthermore, in step A, the mass ratio of sodium 2-naphthol-6-sulfonate hydrate, deionized water and diazonium salt aqueous solution is 1:(20-40):(6-10).

[0024] Furthermore, in step B, the mass ratio of the intermediate, ethanol and sodium hydroxide is 1:(8-10):(0.8-1.0).

[0025] Furthermore, the total mass of the hydrosulfur powder added is 1.5-2.0 times the mass of the intermediate.

[0026] Furthermore, in step C, the mass ratio of the ultraviolet absorber to epichlorohydrin, tetrabutylammonium bromide and sodium hydroxide solution is 1: (1.5-1.8): (0.02-0.03): (1.6-1.7).

[0027] Furthermore, in step C, the concentration of the sodium hydroxide solution is 30wt%.

[0028] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention discloses a denim with ozone fastness and a preparation method thereof. The o-nitroaniline is subjected to diazotization treatment, and a coupling reaction is carried out with sodium 2-naphthol-6-sulfonate hydrate to generate an intermediate, and the intermediate is reduced with hydrosulfite to finally generate a water-soluble benzotriazole ultraviolet absorber. The ultraviolet absorber is made water-soluble by introducing a monomer having a water-soluble group, so that the ultraviolet absorber can be better diffused into the fabric, thereby increasing the utilization rate of the absorber, and can greatly absorb ultraviolet light of different wavelengths, thereby preventing the C=C bond of the plant indigo dye from breaking under ultraviolet light irradiation conditions, thereby improving the light fastness of the plant indigo dyed denim. The ultraviolet absorber is then modified with epichlorohydrin to obtain an epoxidized ultraviolet absorber; the amino group in the amino silicone oil undergoes a ring-opening reaction with the epoxidized ultraviolet absorber to form a secondary amino structure; the structure is then reacted with N,N-dimethyl-2-chloroethylamine hydrochloride and sodium ethanol to generate N,N-dimethylchloroethylamine to generate a tertiary amine compound; finally, the tertiary amine group of the tertiary amine compound undergoes a quaternization reaction with the -Cl of epichlorohydrin to obtain a cationic modifier, which not only provides softness to the fabric, but also improves the yellowing resistance of the amino silicone oil.

[0029] 2. The present invention discloses a denim with ozone fastness and a preparation method thereof. Methyl acrylate, diethylenetriamine, and hexamethylenediamine monomers are used as raw materials, and methanol is used as a reaction medium. An amino-terminated hyperbranched polymer is synthesized through Michael addition reaction and amidation reaction. The polymer contains a large number of amino groups, has a strong reducing effect, and has a strong anti-ozone ability. The epoxy group in the cationic modifier further reacts with the amino-terminated hyperbranched polymer to obtain an ozone fastness enhancer. This modification process introduces a strong cationic group, which greatly enhances the ability to adsorb active dye anions, so that the denim exhibits a better color fixation effect. During soaping and washing, unfixed dye anions can also be adsorbed. At the same time, the cationic modifier is a quaternary ammonium salt, which has excellent antibacterial properties and effectively solves the shortcomings of poor bonding between traditional benzotriazole ultraviolet absorbers and fibers and non-persistent ultraviolet absorption performance. It not only improves the ozone resistance of denim, but also extends its service life, while ensuring its excellent performance in antibacterial and ultraviolet protection. DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] In this embodiment, the denim fabric is made of pure cotton herringbone denim fabric with a unit area mass of 283g / m 2, after water washing, comes from Jiangsu Deliheng Cotton Industry Co., Ltd.; amino silicone oil: model OFX-8040A, comes from Guangzhou Yanghang Chemical Co., Ltd.; insurance powder: sodium dithionite.

[0032] In the following examples and comparative examples, 1 part is equal to 1 g.

[0033] Embodiment 1: A method for preparing denim fabric with high ozone fastness, comprising the following process: Step S1: 100 parts of amino-terminated hyperbranched polymer and 2000 parts of deionized water are mixed evenly, the temperature is raised to 70° C., a mixed solution of 10 parts of cationic modifier and 400 parts of deionized water is added dropwise, the mixture is added over a period of 1 hour, the mixture is kept warm for reaction for 3 hours, and after precipitation, separation and drying, an ozone fastness enhancer is obtained; Step S2: uniformly mixing the ozone fastness enhancer and deionized water to obtain a finishing solution with a concentration of 10 g / L; Step S3: immersing the denim in the finishing liquid, controlling the bath ratio to be 1:30, heating to 50° C. for 30 min, taking out, dehydrating, and then baking at 100° C. for 3 min to obtain the denim with ozone fastness; The preparation method of the amino-terminated hyperbranched polymer is as follows: 12 parts of diethylenetriamine, 125 parts of hexamethylenediamine and 45 parts of methanol were mixed evenly, 85 parts of methyl acrylate were added dropwise for 1 hour, the mixture was reacted at 40°C for 24 hours, the temperature was increased to 140°C at a heating rate of 20°C / h, and the mixture was reacted for 2 hours to obtain an amino-terminated hyperbranched polymer; The preparation method of the cationic modifier is as follows: Step (1): 50 parts of amino silicone oil, 60 parts of epoxidized ultraviolet absorber and 400 parts of anhydrous ethanol are mixed evenly, reacted at 20° C. for 6 hours, and subjected to reduced pressure distillation to obtain modified amino silicone oil; Step (2): 50 parts of modified amino silicone oil and 400 parts of anhydrous ethanol are mixed evenly, 5 parts of sodium ethoxide are added, and the mixture is reacted in an ice bath for 30 minutes to obtain a solution A; 40 parts of N,N-dimethyl-2-chloroethylamine hydrochloride and 320 parts of anhydrous ethanol are mixed evenly, 20 parts of sodium ethoxide are added, and the mixture is reacted in an ice bath for 30 minutes to obtain a solution B; solution A and solution B are mixed evenly, reacted at 50°C for 12 hours, filtered, and distilled under reduced pressure to obtain a tertiary amine compound; Step (3): 50 parts of a tertiary amine compound and 250 parts of deionized water are mixed evenly, concentrated sulfuric acid is used to adjust the pH of the system to 7.0, the temperature is raised to 70°C, 25 parts of epichlorohydrin are added dropwise, the dripping is completed in 0.5 h, and the reaction is carried out for 8 h to obtain a cationic modifier; The preparation method of the epoxidized UV absorber is as follows: Step A: 60 parts of o-nitroaniline, 90 parts of 36 wt% hydrochloric acid and 480 parts of deionized water were mixed, stirred at 25°C for 30 minutes, cooled to 0°C, 15 parts of 12 wt% sodium nitrite aqueous solution were added dropwise, the solution was completed within 1 hour, and the reaction was continued for 30 minutes. Urea was added to remove excess sodium nitrite until the starch-potassium iodide test paper did not turn blue, and then filtered to obtain a diazonium salt aqueous solution; 10 parts of sodium 2-naphthol-6-sulfonate hydrate and 200 parts of deionized water were mixed evenly, the pH of the system was adjusted to 8 with sodium carbonate, and the mixture was placed in an ice-water bath, and 60 parts of a diazonium salt aqueous solution were added dropwise over a period of 1 hour, and the mixture was reacted for 2 hours to obtain an intermediate; Step B: 60 parts of the intermediate, 480 parts of ethanol and 48 parts of sodium hydroxide were mixed evenly, heated to 80°C, 45 parts of sodium hydrosulfite were added every 30 minutes, refluxed for 1 hour, cooled to room temperature, acidified and filtered, and the filter cake was washed and dried to obtain an ultraviolet absorber; Step C: 60 parts of ultraviolet absorber, 90 parts of epichlorohydrin and 1.2 parts of tetrabutylammonium bromide are mixed evenly, reacted at 80°C for 3 hours, cooled to 50°C, 96 parts of 30wt% sodium hydroxide solution are added, and the reaction is continued for 2 hours. After filtering, washing and drying, an epoxidized ultraviolet absorber is obtained.

[0034] Embodiment 2: A method for preparing denim with ozone fastness, comprising the following process: Step S1: 100 parts of amino-terminated hyperbranched polymer and 3000 parts of deionized water are mixed evenly, the temperature is raised to 75° C., a mixed solution of 50 parts of cationic modifier and 900 parts of deionized water is added dropwise, the mixture is added over a period of 1.5 hours, the mixture is kept warm for reaction for 4 hours, and after precipitation, separation and drying, an ozone fastness enhancer is obtained; Step S2: uniformly mixing the ozone fastness enhancer and deionized water to obtain a finishing solution with a concentration of 15 g / L; Step S3: immersing the denim in the finishing liquid, controlling the bath ratio to be 1:40, heating to 55° C. for 40 min, taking out, dehydrating, and then baking at 120° C. for 4 min to obtain the denim with ozone fastness resistance; The preparation method of the amino-terminated hyperbranched polymer is as follows: 13 parts of diethylenetriamine, 130 parts of hexamethylenediamine and 48 parts of methanol were mixed evenly, 90 parts of methyl acrylate were added dropwise, and the mixture was allowed to drip completely over 1.5 hours. The mixture was reacted at 45°C for 18 hours, and the temperature was raised to 150°C at a heating rate of 20°C / h, and the mixture was reacted for 3 hours to obtain an amino-terminated hyperbranched polymer. The preparation method of the cationic modifier is as follows: Step (1): 100 parts of amino silicone oil, 130 parts of epoxidized ultraviolet absorber and 900 parts of anhydrous ethanol are mixed evenly, reacted at 25° C. for 7 hours, and subjected to reduced pressure distillation to obtain modified amino silicone oil; Step (2): 100 parts of modified amino silicone oil and 1000 parts of anhydrous ethanol are mixed evenly, 150 parts of sodium ethoxide are added, and the mixture is reacted in an ice bath for 35 minutes to obtain a solution A; 90 parts of N,N-dimethyl-2-chloroethylamine hydrochloride and 900 parts of anhydrous ethanol are mixed evenly, 50 parts of sodium ethoxide are added, and the mixture is reacted in an ice bath for 35 minutes to obtain a solution B; solution A and solution B are mixed evenly, reacted at 55°C for 18 hours, filtered, and distilled under reduced pressure to obtain a tertiary amine compound; Step (3): 100 parts of a tertiary amine compound and 800 parts of deionized water are mixed evenly, concentrated sulfuric acid is used to adjust the pH of the system to 7.2, the temperature is raised to 75°C, 100 parts of epichlorohydrin are added dropwise, the dripping is completed in 0.8 hours, and the reaction is carried out for 9 hours to obtain a cationic modifier; The preparation method of the epoxidized UV absorber is as follows: Step A: 130 parts of o-nitroaniline, 230 parts of 37 wt% hydrochloric acid and 1170 parts of deionized water were mixed, stirred at 28°C for 35 min, cooled to 3°C, 40 parts of 14 wt% sodium nitrite aqueous solution were added dropwise, the dripping was completed in 1.5 h, and the reaction was carried out for 40 min. Urea was added to remove excess sodium nitrite until the starch-potassium iodide test paper did not turn blue, and then filtered to obtain a diazonium salt aqueous solution; 16 parts of 2-naphthol-6-sulfonic acid sodium hydrate and 480 parts of deionized water were mixed evenly, the pH value of the system was adjusted to 8.5 with sodium carbonate, and the mixture was placed in an ice water bath, and 130 parts of a diazonium salt aqueous solution were added dropwise over 1.5 hours, and the mixture was reacted for 3 hours to obtain an intermediate; Step B: 130 parts of the intermediate, 1170 parts of ethanol and 117 parts of sodium hydroxide were mixed evenly, heated to 85°C, 78 parts of sodium hydrosulfite were added every 30 minutes, refluxed for 1.5 hours, cooled to room temperature, acidified and filtered, and the filter cake was washed and dried to obtain an ultraviolet absorber; Step C: 100 parts of ultraviolet absorber, 170 parts of epichlorohydrin and 2.5 parts of tetrabutylammonium bromide are mixed evenly, reacted at 85°C for 4 hours, cooled to 52°C, 165 parts of 30wt% sodium hydroxide solution are added, and the reaction is continued for 2.5 hours. After filtering, washing and drying, an epoxidized ultraviolet absorber is obtained.

[0035] Embodiment 3: A method for preparing denim with ozone fastness, comprising the following process: Step S1: 100 parts of amino-terminated hyperbranched polymer and 5000 parts of deionized water are mixed evenly, the temperature is raised to 80° C., a mixed solution of 100 parts of cationic modifier and 1000 parts of deionized water is added dropwise for 2 hours, the mixture is kept warm for reaction for 5 hours, and after precipitation, separation and drying, an ozone fastness enhancer is obtained; Step S2: uniformly mixing the ozone fastness enhancer and deionized water to obtain a finishing solution with a concentration of 20 g / L; Step S3: immersing the denim in the finishing liquid, controlling the bath ratio to be 1:50, heating to 60°C for 50 minutes, taking out, dehydrating, and then baking at 150°C for 5 minutes to obtain the denim with ozone fastness; The preparation method of the amino-terminated hyperbranched polymer is as follows: 14 parts of diethylenetriamine, 138 parts of hexamethylenediamine and 50 parts of methanol were mixed evenly, 95 parts of methyl acrylate were added dropwise, and the mixture was allowed to drip completely over 2 hours. The mixture was reacted at 50°C for 12 hours, and the temperature was raised to 160°C at a heating rate of 20°C / h, and the mixture was reacted for 4 hours to obtain an amino-terminated hyperbranched polymer. The preparation method of the cationic modifier is as follows: Step (1): 100 parts of amino silicone oil, 150 parts of epoxidized ultraviolet absorber and 1000 parts of anhydrous ethanol are mixed evenly, reacted at 30° C. for 8 hours, and subjected to reduced pressure distillation to obtain modified amino silicone oil; Step (2): 100 parts of modified amino silicone oil and 1200 parts of anhydrous ethanol are mixed evenly, 20 parts of sodium ethoxide are added, and the mixture is reacted in an ice bath for 40 minutes to obtain a solution A; 100 parts of N,N-dimethyl-2-chloroethylamine hydrochloride and 1200 parts of anhydrous ethanol are mixed evenly, 60 parts of sodium ethoxide are added, and the mixture is reacted in an ice bath for 40 minutes to obtain a solution B; solution A and solution B are mixed evenly, reacted at 60°C for 24 hours, filtered, and distilled under reduced pressure to obtain a tertiary amine compound; Step (3): 100 parts of a tertiary amine compound and 1000 parts of deionized water are mixed evenly, concentrated sulfuric acid is used to adjust the pH value of the system to 7.5, the temperature is raised to 80°C, 1500 parts of epichlorohydrin are added dropwise, the dripping is completed within 1.0 hour, and the reaction is carried out for 10 hours to obtain a cationic modifier; The preparation method of the epoxidized UV absorber is as follows: Step A: 150 parts of o-nitroaniline, 300 parts of 38 wt% hydrochloric acid and 1500 parts of deionized water were mixed, stirred at 30°C for 40 minutes, cooled to 5°C, 52.5 parts of 16 wt% sodium nitrite aqueous solution were added dropwise, the mixture was added over 2 hours, reacted for 50 minutes, urea was added to remove excess sodium nitrite, until the starch-potassium iodide test paper did not turn blue, and then filtered to obtain a diazonium salt aqueous solution; 15 parts of sodium 2-naphthol-6-sulfonate hydrate and 600 parts of deionized water were mixed evenly, the pH of the system was adjusted to 9 with sodium carbonate, and the mixture was placed in an ice-water bath, and 150 parts of a diazonium salt aqueous solution were added dropwise over a period of 2 hours, and the mixture was reacted for 4 hours to obtain an intermediate; Step B: 150 parts of the intermediate, 1500 parts of ethanol and 150 parts of sodium hydroxide are mixed evenly, heated to 90°C, 75 parts of sodium hydrosulfite are added every 30 minutes, refluxed for 2 hours, cooled to room temperature, acidified and filtered, and the filter cake is washed and dried to obtain an ultraviolet absorber; Step C: 150 parts of ultraviolet absorber, 270 parts of epichlorohydrin and 4.5 parts of tetrabutylammonium bromide are mixed evenly, reacted at 90°C for 5 hours, cooled to 55°C, 255 parts of 30wt% sodium hydroxide solution are added, and the reaction is continued for 3 hours. After filtering, washing and drying, an epoxidized ultraviolet absorber is obtained.

[0036] Comparative Example 1: A method for preparing denim with ozone fastness, comprising the following process: Compared with Example 2, in Comparative Example 1, the ozone fastness enhancer is replaced with an amino-terminated hyperbranched polymer of the same mass, and the other steps are the same as those of Example 2.

[0037] Comparative Example 2: A method for preparing denim with ozone fastness, comprising the following process: Compared with Example 2, Comparative Example 2 replaces the epoxidized UV absorber with a UV absorber of the same mass, and the other steps are the same as those of Example 2.

[0038] Comparative Example 3: A method for preparing denim with ozone fastness, comprising the following process: Compared with Example 2, in step S2 of Comparative Example 3, the mass of the cationic modifier is twice the mass of the amino-terminated hyperbranched polymer, and the other steps are the same as those of Example 2.

[0039] Experiment: Take the ozone fastness denim obtained in Examples 1-3 and Comparative Examples 1-3, prepare samples, test their properties respectively and record the test results: The color fastness to light was tested in accordance with GB / T 8427-2019 "Textiles - Tests for color fastness - Color fastness to artificial light: Xenon arc oscillation", and the sample size was 100mm×50mm; the color fastness to ozone was tested in accordance with GB / T 11039.3-2005 "Textiles - Tests for color fastness - Color fastness to atmospheric pollutants - Part 3: Atmospheric ozone", and the sample size was 60mm×100mm; the antibacterial rate was tested in accordance with GB / T20944.3-2008 "Evaluation of antibacterial properties of textiles - Part 3: Oscillation method", the sample size was 5mm×5mm, and the bacteria used were Staphylococcus aureus (ATCC 6538).

[0040] The test results are as follows:

[0041] According to the data in the above table, we can clearly draw the following conclusions: 1. Compared with Examples 1-3, the light fastness and antibacterial rate of the products obtained in Comparative Examples 1 and 2 are reduced, indicating that the ozone fastness enhancer prepared by the present invention has better UV resistance and antibacterial properties than the amino-terminated hyperbranched polymer; at the same time, the present invention can participate in subsequent chemical reactions by epoxidation modification of the ultraviolet absorber.

[0042] 2. Compared with Examples 1-3, the color fastness to ozone of the product obtained in Comparative Example 3 is reduced. It can be seen that when an excessive amount of cationic modifier is added, the primary amine content in the color fastness to ozone is reduced, thereby causing a decrease in the color fastness to ozone.

[0043] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be considered exemplary and non-restrictive in all respects, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention.

Claims

1. A method for preparing denim with ozone fastness, characterized in that: The steps include: Step S1: uniformly mix the amino-terminated hyperbranched polymer and deionized water, raise the temperature to 70-80° C., dropwise add a mixed solution of a cationic modifier and deionized water, and complete the dropwise addition for 1-2 hours. Keep the temperature for reaction for 3-5 hours, and obtain an ozone fastness enhancer after precipitation, separation, and drying. Step S2: uniformly mixing the ozone fastness enhancer and deionized water to obtain a finishing solution; Step S3: immersing the denim into the finishing liquid, heating it to 50-60°C for 30-50 minutes, taking it out, dehydrating it, and then baking it at 100-150°C for 3-5 minutes to obtain the denim with ozone fastness; The preparation method of the cationic modifier is as follows: Step (1): uniformly mixing amino silicone oil, epoxidized ultraviolet absorber and anhydrous ethanol, reacting at 20-30° C. for 6-8 hours, and distilling under reduced pressure to obtain modified amino silicone oil; Step (2): uniformly mix the modified amino silicone oil and anhydrous ethanol, add sodium ethoxide, and react for 30-40 minutes in an ice bath to obtain solution A; uniformly mix N,N-dimethyl-2-chloroethylamine hydrochloride and anhydrous ethanol, add sodium ethoxide, and react for 30-40 minutes in an ice bath to obtain solution B; uniformly mix solution A and solution B, react at 50-60° C. for 12-14 hours, filter, and distill under reduced pressure to obtain a tertiary amine compound; Step (3): Evenly mix the tertiary amine compound and deionized water, adjust the system pH to 7.0-7.5 with concentrated sulfuric acid, raise the temperature to 70-80°C, drop epichlorohydrin, add the dropwise addition over 0.5-1.0h, react for 8-10h, and obtain a cationic modifier.

2. The method for preparing ozone fastness denim according to claim 1, characterized in that: In the step S1, the mass of the cationic modifier is 0.1-1.0 times the mass of the amino-terminated hyperbranched polymer.

3. The method for preparing ozone fastness denim according to claim 1, characterized in that: In step S2, the concentration of the finishing liquid is 10-20 g / L.

4. The method for preparing ozone fastness denim according to claim 1, characterized in that: The preparation method of the amino-terminated hyperbranched polymer is as follows: Diethylenetriamine, hexamethylenediamine and methanol are mixed evenly, methyl acrylate is added dropwise over 1-2 hours, the mixture is reacted at 40-50°C for 24-48 hours, the temperature is increased to 140-160°C at a heating rate of 20°C / h, and the reaction is performed for 2-4 hours to obtain an amino-terminated hyperbranched polymer.

5. The method for preparing ozone fastness denim according to claim 4, characterized in that: The amino-terminated hyperbranched polymer comprises the following components by weight: 12-14 parts of diethylenetriamine, 125-138 parts of hexamethylenediamine, 45-50 parts of methanol and 85-95 parts of methyl acrylate.

6. The method for preparing ozone fastness denim according to claim 1, characterized in that: In the step (1), the mass ratio of amino silicone oil, epoxidized ultraviolet absorber and anhydrous ethanol is 1: (1.2-1.5): (8-10).

7. The method for preparing ozone fastness denim according to claim 6, characterized in that: The preparation method of the epoxidized ultraviolet absorber is as follows: Step A: o-nitroaniline, hydrochloric acid and deionized water are mixed, stirred at 25-30°C for 30-40 minutes, cooled to 0-5°C, sodium nitrite aqueous solution is added dropwise, the dripping is completed in 1-2 hours, and the reaction is carried out for 30-50 minutes. Urea is added to remove excess sodium nitrite until the starch-potassium iodide test paper does not turn blue, and then filtered to obtain a diazonium salt aqueous solution; Mix 2-naphthol-6-sulfonic acid sodium hydrate and deionized water evenly, adjust the system pH to 8-9 with sodium carbonate, place in an ice water bath, add diazonium salt aqueous solution dropwise, drip for 1-2 hours, react for 2-4 hours, and obtain an intermediate; Step B: The intermediate, ethanol and sodium hydroxide are mixed evenly, heated to 80-90°C, and sodium hydroxide is added every 30 minutes. The mixture is refluxed for 1-2 hours, cooled to room temperature, acidified and filtered, and the filter cake is washed and dried to obtain a UV absorber; Step C: uniformly mix the ultraviolet absorber, epichlorohydrin and tetrabutylammonium bromide, react at 80-90°C for 3-5h, cool to 50-55°C, add sodium hydroxide solution, continue to react for 2-3h, filter, wash and dry to obtain the epoxidized ultraviolet absorber.

8. The method for preparing ozone fastness denim according to claim 1, characterized in that: Furthermore, in step (3), the mass ratio of the tertiary amine compound, deionized water and epichlorohydrin is 1:(5-10):(0.5-1.5).

9. A denim with ozone fastness obtained according to the preparation method according to any one of claims 1 to 8.

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