A denim fabric with ozone fastness and its preparation method

Abstract

The present invention relates to the technical field of textile, and specifically to a denim fabric with ozone fastness and a preparation method thereof. The present invention includes the following steps: Step S1: Mix an amino-terminated hyperbranched polymer and deionized water evenly, heat up to 70-80 °C, dropwise add a mixed solution of a cationic modifier and deionized water, finish dropping in 1-2 h, keep the temperature for reaction for 3-5 h, and after precipitation separation and drying, obtain an ozone color fastness improver; Step S2: Mix the ozone color fastness improver and deionized water evenly to obtain a finishing solution; Step S3: Immerse the denim fabric in the finishing solution, heat up to 50-60 °C and treat for 30-50 min, take it out, dehydrate, and then bake at 100-150 °C for 3-5 min to obtain the denim fabric with ozone fastness, which not only has excellent ozone resistance performance, but also has excellent ultraviolet protection effect and antibacterial effect, and prolongs its service life.

Description

Technical Field

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

[0002] With the acceleration of the industrialization process and the sharp increase in the number of urban cars, the amount of ozone in the air has increased significantly, even reaching a level that endangers 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 contact with ozone. Ozone (O 3 ) in the atmosphere is a very strong oxidant. Under the irradiation of (UV) ultraviolet light, it will cause the dye to decompose and discolor. The indigo dye used for dyeing denim fabrics has the characteristic of being prone to yellowing due to oxidation intolerance. Indigo will decompose into isatin (2,3-dihydroindole dione), tannic acid and their combination under the action of ozone, resulting in the yellowing of the fabric. This not only changes the color of the denim, but 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 and a preparation method thereof. Summary of the Invention

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

[0006] To achieve the above purpose, the present invention provides the following technical solutions:

[0007] A preparation method of a denim fabric with ozone fastness includes the following steps:

[0008] Step S1: Mix the amino-terminated hyperbranched polymer and deionized water evenly, heat up to 70 - 80 °C, dropwise add the mixed solution of the cationic modifier and deionized water, finish dropping in 1 - 2 h, keep the temperature for reaction for 3 - 5 h, and obtain the ozone fastness improver after precipitation separation and drying;

[0009] Step S2: Mix the ozone fastness improver and deionized water evenly to obtain the finishing solution;

[0010] Step S3: Immerse the denim fabric in the finishing solution, heat up to 50 - 60 °C and treat for 30 - 50 min, take out, dehydrate, and then bake at 100 - 150 °C for 3 - 5 min to obtain the denim fabric with ozone fastness.

[0011] Further, in the step S1, the mass ratio of the amino-terminated hyperbranched polymer to deionized water is 1:(20 - 50).

[0012] Further, in the 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).

[0013] Further, in the step S2, the concentration of the ozone fastness improver in the finishing liquor is 10 - 20 g / L.

[0014] Further, in the step S3, the bath ratio of the denim to the finishing liquor is 1:(30 - 50).

[0015] Further, the preparation method of the amino-terminated hyperbranched polymer is as follows:

[0016] Mix diethylenetriamine, hexamethylenediamine and methanol evenly, dropwise add methyl acrylate, and finish dropping in 1 - 2 h. React at 40 - 50 °C for 12 - 24 h, then heat up to 140 - 160 °C at a heating rate of 20 °C / h and react for 2 - 4 h to obtain the amino-terminated hyperbranched polymer.

[0017] Further, the amino-terminated hyperbranched polymer comprises the following weight components: 12 - 14 parts of diethylenetriamine, 125 - 138 parts of hexamethylenediamine, 45 - 50 parts of methanol, and 85 - 95 parts of methyl acrylate.

[0018] Further, the preparation method of the cationic modifier is as follows:

[0019] Step (1): Mix amino silicone oil, epoxy ultraviolet absorber and absolute ethanol evenly, react at 20 - 30 °C for 6 - 8 h, and obtain modified amino silicone oil through vacuum distillation;

[0020] Step (2): Mix the modified amino silicone oil and absolute ethanol evenly, add sodium ethoxide, and react under ice bath conditions for 30 - 40 min to obtain solution A; mix N,N-dimethyl-2-chloroethylamine hydrochloride and absolute ethanol evenly, add sodium ethoxide, and react under ice bath conditions for 30 - 40 min to obtain solution B; mix solution A and solution B evenly, react at 50 - 60 °C for 12 - 24 h, and obtain a tertiary amine compound after filtration and vacuum distillation;

[0021] Step (3): Mix the tertiary amine compound and deionized water evenly, adjust the pH of the system to 7.0 - 7.5 with concentrated sulfuric acid, heat up to 70 - 80 °C, dropwise add epichlorohydrin, finish dropping in 0.5 - 1.0 h, and react for 8 - 10 h to obtain the cationic modifier.

[0022] In the above technical solution, 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, and a tertiary amine compound is formed; finally, a quaternization reaction occurs between the tertiary amine group of the tertiary amine compound and -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 improver.

[0023] Further, in the step (1), the mass ratio of the amino silicone oil, the epoxidized ultraviolet absorber and absolute ethanol is 1:(1.2 - 1.5):(8 - 10).

[0024] Further, in the step (2), the mass ratio of the modified amino silicone oil, absolute ethanol and sodium ethoxide is 1:(8 - 12):(0.1 - 0.2).

[0025] Further, in the step (2), the mass ratio of N,N-dimethyl-2-chloroethylamine hydrochloride, absolute 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.

[0026] Further, in the step (3), the mass ratio of the tertiary amine compound, deionized water and epichlorohydrin is 1:(5 - 10):(0.5 - 1.5).

[0027] Further, the preparation method of the epoxidized ultraviolet absorber is as follows:

[0028] Step A: Mix o-nitroaniline, hydrochloric acid and deionized water, stir at 25 - 30 °C for 30 - 40 min, cool to 0 - 5 °C, dropwise add an aqueous solution of sodium nitrite, finish dropping in 1 - 2 h, react for 30 - 50 min, add urea to remove the excess sodium nitrite until the starch-iodide test paper no longer turns blue, and then filter to obtain a diazonium salt aqueous solution;

[0029] Mix 2-naphthol-6-sulfonic acid sodium hydrate and deionized water evenly, adjust the pH of the system to 8 - 9 with sodium carbonate, place it in an ice-water bath, dropwise add the diazonium salt aqueous solution, finish dropping in 1 - 2 h, and react for 2 - 4 h to obtain an intermediate;

[0030] Step B: Mix the intermediate, ethanol and sodium hydroxide evenly, heat to 80 - 90 °C, add sodium dithionite every 30 min, reflux and react for 1 - 2 h, cool to room temperature, carry out acidification and filtration, and after washing and drying the filter cake, obtain the ultraviolet absorber;

[0031] Step C: Mix the ultraviolet absorber, epichlorohydrin, and tetrabutylammonium bromide evenly, react at 80 - 90 °C for 3 - 5 h, cool down to 50 - 55 °C, add sodium hydroxide solution, and continue to react for 2 - 3 h. After filtration, washing, and drying, the epoxidized ultraviolet absorber is obtained.

[0032] In the above technical solution, o-nitroaniline is diazotized and coupled with 2-naphthol-6-sulfonic acid hydrate to form a 2-naphthol-7-sulfonyl azo o-nitrobenzene intermediate. Then, the intermediate is reduced with sodium dithionite to finally form a water-soluble benzotriazole ultraviolet absorber. Further, epichlorohydrin is used to modify the ultraviolet absorber to prepare an epoxy monomer containing an ultraviolet absorption group, that is, the epoxidized ultraviolet absorber.

[0033] Further, 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 - 38 wt%.

[0034] Further, in step A, the concentration of the sodium nitrite aqueous solution is 12 - 16 wt%, and its dosage is 25 - 35% of the mass of o-nitroaniline.

[0035] Further, in step A, the mass ratio of 2-naphthol-6-sulfonic acid hydrate, deionized water, and the diazonium salt aqueous solution is 1:(20 - 40):(6 - 10).

[0036] Further, in step B, the mass ratio of the intermediate, ethanol, and sodium hydroxide is 1:(8 - 10):(0.8 - 1.0).

[0037] Further, the total mass of sodium dithionite added is 1.5 - 2.0 times the mass of the intermediate.

[0038] Further, in step C, the mass ratio of the ultraviolet absorber, epichlorohydrin, tetrabutylammonium bromide, and sodium hydroxide solution is 1:(1.5 - 1.8):(0.02 - 0.03):(1.6 - 1.7).

[0039] Further, in step C, the concentration of the sodium hydroxide solution is 30 wt%.

[0040] Compared with the prior art, the beneficial effects of the present invention are:

[0041] 1. A kind of indigo denim fabric with ozone fastness and its preparation method according to the present invention. Through diazotization of o-nitroaniline and coupling reaction with 2-naphthol-6-sulfonic acid sodium hydrate to generate an intermediate, and then reducing the intermediate with sodium dithionite, a water-soluble benzotriazole ultraviolet absorber is finally generated. By introducing a monomer with a water-soluble group, the ultraviolet absorber has water solubility, so as to better diffuse into the fabric, improve the utilization rate of the absorber, can absorb ultraviolet light in a wide range of wavelengths, prevent the breakage of the C=C bond of indigo dye under ultraviolet irradiation, and thus improve the light fastness of indigo dyed denim fabric;

[0042] After that, epichlorohydrin is used to modify the ultraviolet absorber to obtain an epoxidized ultraviolet absorber; through the ring-opening reaction of the amino group in amino silicone oil with the epoxidized ultraviolet absorber to form a secondary amino structure; then reacting with N,N-dimethyl-2-chloroethylamine hydrochloride and sodium ethoxide to generate N,N-dimethylchloroethylamine, and generating a tertiary amine compound; finally, through the quaternization reaction of the tertiary amine group of the tertiary amine compound with -Cl of epichlorohydrin, a cationic modifier is obtained, which not only provides the softness of the fabric but also improves the yellowing resistance of amino silicone oil.

[0043] 2. A kind of indigo denim fabric with ozone fastness and its preparation method according to the present invention. Using methyl acrylate, diethylenetriamine, and hexamethylenediamine monomers as raw materials and methanol as the reaction medium, a terminal amino hyperbranched polymer is synthesized through Michael addition reaction and amidation reaction. It contains a large number of amino groups, has a large reducing effect, and strong anti-ozone ability; through the further reaction of the epoxy group in the cationic modifier with the terminal amino hyperbranched polymer, a ozone fastness improver is obtained. This modification process introduces strong cationic groups, greatly enhancing the ability to adsorb anionic reactive dyes, making the denim fabric show good color fixation effect. During soaping and washing, it can also adsorb unfixed dye anions; at the same time, the cationic modifier is a quaternary ammonium salt with excellent antibacterial properties, effectively solving the disadvantages of poor binding between traditional benzotriazole ultraviolet absorbers and fibers and non-persistent ultraviolet absorption performance. It not only improves the ozone fastness of denim fabric but also extends its service life, while ensuring its excellent performance in antibacterial and anti-ultraviolet aspects. Specific embodiments

[0044] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

[0045] In this embodiment, the denim fabric: pure cotton herringbone twill denim fabric, with a unit area mass of 283 g / m2 , after being washed with water, it is sourced from Jiangsu Deliheng Cotton Industry Co., Ltd.; amino silicone oil: model OFX-8040A, sourced from Guangzhou Yanghang Chemical Co., Ltd.; sodium hydrosulfite: sodium dithionite.

[0046] In the following examples and comparative examples, 1 part is equal to 1 g.

[0047] Example 1: A preparation method of ozone-fastness denim, comprising the following processes:

[0048] Step S1: Mix 100 parts of amino-terminated hyperbranched polymer and 2000 parts of deionized water evenly, heat up to 70 °C, and dropwise add a mixed solution of 10 parts of cationic modifier and 400 parts of deionized water. Finish dropping in 1 h, keep the temperature for reaction for 3 h, and after precipitation separation and drying, obtain an ozone color fastness improver;

[0049] Step S2: Mix the ozone color fastness improver and deionized water evenly to obtain a finishing solution with a concentration of 10 g / L;

[0050] Step S3: Immerse the denim in the finishing solution, control the bath ratio to 1:30, heat up to 50 °C and treat for 30 min, take out, dehydrate, and then bake at 100 °C for 3 min to obtain ozone-fastness denim;

[0051] The preparation method of the amino-terminated hyperbranched polymer is as follows:

[0052] Mix 12 parts of diethylenetriamine, 125 parts of hexamethylenediamine and 45 parts of methanol evenly, dropwise add 85 parts of methyl acrylate, finish dropping in 1 h, react at 40 °C for 24 h, heat up to 140 °C at a heating rate of 20 °C / h, and react for 2 h to obtain the amino-terminated hyperbranched polymer;

[0053] The preparation method of the cationic modifier is as follows:

[0054] Step (1): Mix 50 parts of amino silicone oil, 60 parts of epoxy ultraviolet absorber and 400 parts of absolute ethanol evenly, react at 20 °C for 6 h, and after vacuum distillation, obtain modified amino silicone oil;

[0055] Step (2): Mix 50 parts of modified amino silicone oil and 400 parts of absolute ethanol evenly, add 5 parts of sodium ethoxide, and react for 30 min under ice bath conditions to obtain solution A; mix 40 parts of N,N-dimethyl-2-chloroethylamine hydrochloride and 320 parts of absolute ethanol evenly, add 20 parts of sodium ethoxide, and react for 30 min under ice bath conditions to obtain solution B; mix solution A and solution B evenly, react at 50 °C for 12 h, and after filtration and vacuum distillation, obtain a tertiary amine compound;

[0056] Step (3): Mix 50 parts of tertiary amine compound and 250 parts of deionized water evenly, adjust the pH of the system to 7.0 with concentrated sulfuric acid, heat up to 70 °C, dropwise add 25 parts of epichlorohydrin, finish dropping in 0.5 h, react for 8 h to obtain a cationic modifier;

[0057] The preparation method of the epoxidized ultraviolet absorber is as follows:

[0058] Step A: Mix 60 parts of o-nitroaniline, 90 parts of 36 wt% hydrochloric acid and 480 parts of deionized water, stir at 25 °C for 30 min, cool to 0 °C, dropwise add 15 parts of 12 wt% sodium nitrite aqueous solution, finish dropping in 1 h, react for 30 min, add urea to remove the excess sodium nitrite until the starch-potassium iodide test paper no longer turns blue, and then filter to obtain a diazonium salt aqueous solution;

[0059] Mix 10 parts of 2-naphthol-6-sulfonic acid sodium hydrate and 200 parts of deionized water evenly, adjust the pH of the system to 8 with sodium carbonate, place it in an ice-water bath, dropwise add 60 parts of the diazonium salt aqueous solution, finish dropping in 1 h, react for 2 h to obtain an intermediate;

[0060] Step B: Mix 60 parts of the intermediate, 480 parts of ethanol and 48 parts of sodium hydroxide evenly, heat to 80 °C, add 45 parts of sodium dithionite every 30 min, reflux and react for 1 h, cool to room temperature, carry out acidification and filtration, and after washing and drying the filter cake, obtain an ultraviolet absorber;

[0061] Step C: Mix 60 parts of the ultraviolet absorber, 90 parts of epichlorohydrin and 1.2 parts of tetrabutylammonium bromide evenly, react at 80 °C for 3 h, cool to 50 °C, add 96 parts of 30 wt% sodium hydroxide solution, continue to react for 2 h, and after filtration, washing and drying, obtain the epoxidized ultraviolet absorber.

[0062] Example 2: A preparation method of ozone-fastness denim, including the following processes:

[0063] Step S1: Mix 100 parts of terminal amino hyperbranched polymer and 3000 parts of deionized water evenly, heat up to 75 °C, dropwise add a mixed solution of 50 parts of cationic modifier and 900 parts of deionized water, finish dropping in 1.5 h, keep warm and react for 4 h, and after precipitation separation and drying, obtain an ozone color fastness improver;

[0064] Step S2: Mix the ozone color fastness improver and deionized water evenly to obtain a finishing solution with a concentration of 15 g / L;

[0065] Step S3: Immerse the denim in the finishing solution, control the bath ratio to 1:40, heat up to 55 °C and treat for 40 min, take out, dehydrate, and then bake at 120 °C for 4 min to obtain ozone-fastness denim;

[0066] The preparation method of the amino-terminated hyperbranched polymer is as follows:

[0067] Mix 13 parts of diethylenetriamine, 130 parts of hexamethylenediamine and 48 parts of methanol evenly, dropwise add 90 parts of methyl acrylate, finish dropping in 1.5 h, react at 45 °C for 18 h, raise the temperature to 150 °C at a heating rate of 20 °C / h, and react for 3 h to obtain the amino-terminated hyperbranched polymer;

[0068] The preparation method of the cationic modifier is as follows:

[0069] Step (1): Mix 100 parts of amino silicone oil, 130 parts of epoxy ultraviolet absorber and 900 parts of absolute ethanol evenly, react at 25 °C for 7 h, and obtain modified amino silicone oil through vacuum distillation;

[0070] Step (2): Mix 100 parts of modified amino silicone oil and 1000 parts of absolute ethanol evenly, add 150 parts of sodium ethoxide, and react for 35 min under ice bath conditions to obtain solution A; Mix 90 parts of N,N-dimethyl-2-chloroethylamine hydrochloride and 900 parts of absolute ethanol evenly, add 50 parts of sodium ethoxide, and react for 35 min under ice bath conditions to obtain solution B; Mix solution A and solution B evenly, react at 55 °C for 18 h, and obtain a tertiary amine compound after filtration and vacuum distillation;

[0071] Step (3): Mix 100 parts of the tertiary amine compound and 800 parts of deionized water evenly, adjust the pH of the system to 7.2 with concentrated sulfuric acid, raise the temperature to 75 °C, dropwise add 100 parts of epichlorohydrin, finish dropping in 0.8 h, and react for 9 h to obtain the cationic modifier;

[0072] The preparation method of the epoxy ultraviolet absorber is as follows:

[0073] Step A: Mix 130 parts of o-nitroaniline, 230 parts of 37 wt% hydrochloric acid and 1170 parts of deionized water, stir at 28 °C for 35 min, cool to 3 °C, dropwise add 40 parts of 14 wt% sodium nitrite aqueous solution, finish dropping in 1.5 h, react for 40 min, add urea to remove the excess sodium nitrite until the starch-potassium iodide test paper no longer turns blue, and obtain a diazonium salt aqueous solution after filtration;

[0074] Mix 16 parts of 2-naphthol-6-sulfonic acid sodium hydrate and 480 parts of deionized water evenly, adjust the pH of the system to 8.5 with sodium carbonate, place it in an ice-water bath, dropwise add 130 parts of the diazonium salt aqueous solution, finish dropping in 1.5 h, and react for 3 h to obtain an intermediate;

[0075] Step B: Mix 130 parts of the intermediate, 1170 parts of ethanol, and 117 parts of sodium hydroxide evenly, heat to 85 °C, add 78 parts of sodium dithionite every 30 minutes, reflux for 1.5 hours, cool to room temperature, perform acidification and filtration. After washing and drying the filter cake, an ultraviolet absorber is obtained.

[0076] Step C: Mix 100 parts of the ultraviolet absorber, 170 parts of epichlorohydrin, and 2.5 parts of tetrabutylammonium bromide evenly, react at 85 °C for 4 hours, cool to 52 °C, add 165 parts of 30 wt% sodium hydroxide solution, and continue to react for 2.5 hours. After filtration, washing, and drying, an epoxidized ultraviolet absorber is obtained.

[0077] Example 3: A preparation method of ozone-fastness denim, comprising the following processes:

[0078] Step S1: Mix 100 parts of the amino-terminated hyperbranched polymer and 5000 parts of deionized water evenly, heat to 80 °C, dropwise add a mixed solution of 100 parts of the cationic modifier and 1000 parts of deionized water, finish dropping in 2 hours, keep warm and react for 5 hours. After precipitation separation and drying, a ozone color fastness improver is obtained.

[0079] Step S2: Mix the ozone color fastness improver and deionized water evenly to obtain a finishing solution with a concentration of 20 g / L.

[0080] Step S3: Immerse the denim in the finishing solution, control the bath ratio to 1:50, heat to 60 °C and treat for 50 minutes, take out, dehydrate, and then bake at 150 °C for 5 minutes to obtain ozone-fastness denim.

[0081] The preparation method of the amino-terminated hyperbranched polymer is as follows:

[0082] Mix 14 parts of diethylenetriamine, 138 parts of hexamethylenediamine, and 50 parts of methanol evenly, dropwise add 95 parts of methyl acrylate, finish dropping in 2 hours, react at 50 °C for 12 hours, heat to 160 °C at a heating rate of 20 °C / h, and react for 4 hours to obtain the amino-terminated hyperbranched polymer.

[0083] The preparation method of the cationic modifier is as follows:

[0084] Step (1): Mix 100 parts of amino silicone oil, 150 parts of the epoxidized ultraviolet absorber, and 1000 parts of absolute ethanol evenly, react at 30 °C for 8 hours, and perform vacuum distillation to obtain the modified amino silicone oil.

[0085] Step (2): Mix 100 parts of modified amino silicone oil and 1200 parts of absolute ethanol evenly, add 20 parts of sodium ethoxide, and react for 40 min under ice bath conditions to obtain solution A; mix 100 parts of N,N-dimethyl-2-chloroethylamine hydrochloride and 1200 parts of absolute ethanol evenly, add 60 parts of sodium ethoxide, and react for 40 min under ice bath conditions to obtain solution B; mix solution A and solution B evenly, react at 60 °C for 24 h, and after filtration and vacuum distillation, obtain a tertiary amine compound;

[0086] Step (3): Mix 100 parts of the tertiary amine compound and 1000 parts of deionized water evenly, adjust the pH of the system to 7.5 with concentrated sulfuric acid, heat to 80 °C, dropwise add 1500 parts of epichlorohydrin, finish dropping in 1.0 h, and react for 10 h to obtain a cationic modifier;

[0087] The preparation method of the epoxidized ultraviolet absorber is as follows:

[0088] Step A: Mix 150 parts of o-nitroaniline, 300 parts of 38 wt% hydrochloric acid and 1500 parts of deionized water, stir at 30 °C for 40 min, cool to 5 °C, dropwise add 52.5 parts of 16 wt% sodium nitrite aqueous solution, finish dropping in 2 h, react for 50 min, add urea to remove the excess sodium nitrite until the starch-potassium iodide test paper no longer turns blue, and after filtration, obtain a diazonium salt aqueous solution;

[0089] Mix 15 parts of 2-naphthol-6-sulfonic acid sodium hydrate and 600 parts of deionized water evenly, adjust the pH of the system to 9 with sodium carbonate, place in an ice-water bath, dropwise add 150 parts of the diazonium salt aqueous solution, finish dropping in 2 h, and react for 4 h to obtain an intermediate;

[0090] Step B: Mix 150 parts of the intermediate, 1500 parts of ethanol and 150 parts of sodium hydroxide evenly, heat to 90 °C, add 75 parts of sodium dithionite every 30 min, reflux and react for 2 h, cool to room temperature, carry out acidification and filtration, and after the filter cake is washed and dried, obtain an ultraviolet absorber;

[0091] Step C: Mix 150 parts of the ultraviolet absorber, 270 parts of epichlorohydrin and 4.5 parts of tetrabutylammonium bromide evenly, react at 90 °C for 5 h, cool to 55 °C, add 255 parts of 30 wt% sodium hydroxide solution, continue to react for 3 h, and after filtration, washing and drying, obtain the epoxidized ultraviolet absorber.

[0092] Comparative Example 1: The preparation method of a denim fabric with ozone fastness includes the following processes:

[0093] Compared with Example 2, in Comparative Example 1, the ozone color fastness improver was replaced with an end-amino hyperbranched polymer of the same mass, and other steps were the same as those in Example 2.

[0094] Comparative Example 2: A preparation method of ozone-fastness denim, comprising the following processes:

[0095] Compared with Example 2, in Comparative Example 2, the epoxy ultraviolet absorber was replaced with the same mass of ultraviolet absorber, and other steps were the same as those in Example 2.

[0096] Comparative Example 3: A preparation method of ozone-fastness denim, comprising the following processes:

[0097] Compared with Example 2, in step S2 of Comparative Example 3, the mass of the cationic modifier was 2 times the mass of the amino-terminated hyperbranched polymer, and other steps were the same as those in Example 2.

[0098] Experiment: Take the ozone-fastness denim obtained in Examples 1-3 and Comparative Examples 1-3, prepare specimens, and detect and record the test results of their properties respectively:

[0099] The light fastness was tested according to GB / T 8427-2019 "Textiles - Tests for colour fastness - Colour fastness to artificial light: Xenon arc", and the specimen size was 100 mm × 50 mm; the ozone fastness was tested according to GB / T 11039.3-2005 "Textiles - Tests for colour fastness - Colour fastness to atmospheric pollutants - Part 3: Atmospheric ozone", and the specimen size was 60 mm × 100 mm; the antibacterial rate was tested according to GB / T20944.3-2008 "Textiles - Evaluation of antibacterial properties - Part 3: Oscillation method", the specimen size was 5 mm × 5 mm, and the strain used was Staphylococcus aureus (ATCC 6538).

[0100] The test results are as follows:

[0101]

[0102] According to the data in the above table, the following conclusions can be clearly obtained:

[0103] 1. Compared with Examples 1-3, the light fastness and antibacterial rate of the products obtained in Comparative Examples 1 and 2 decreased, indicating that the ozone fastness improver prepared by the present invention has better ultraviolet resistance and antibacterial properties compared with the amino-terminated hyperbranched polymer; at the same time, by epoxidizing the ultraviolet absorber, the present invention can participate in subsequent chemical reactions.

[0104] 2. Compared with Examples 1-3, the ozone fastness of the product obtained in Comparative Example 3 decreased. It can be seen that when an excessive amount of cationic modifier is added, the primary amine content in the ozone fastness will decrease, resulting in a decrease in the ozone fastness.

[0105] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above-described exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be embraced within 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): uniformly 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, dropwise add epichlorohydrin, and complete the dropwise addition over 0.5-1.0h, react for 8-10h, and obtain a cationic modifier; 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 mixing the ultraviolet absorber, epichlorohydrin and tetrabutylammonium bromide, reacting at 80-90°C for 3-5h, cooling to 50-55°C, adding sodium hydroxide solution, continuing to react for 2-3h, filtering, washing and drying to obtain an epoxidized ultraviolet absorber; In the step S1, the mass of the cationic modifier is 0.1-1.0 times the mass of the amino-terminated hyperbranched polymer.

2. 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.

3. 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.

4. The method for preparing ozone fastness denim according to claim 1, characterized in that: The amino-terminated hyperbranched polymer is prepared from the following raw materials in parts by weight: 12-14 parts of diethylenetriamine, 125-138 parts of hexamethylenediamine, 45-50 parts of methanol, and 85-95 parts of methyl acrylate.

5. 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).

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

7. A denim with ozone fastness obtained according to the preparation method according to any one of claims 1 to 6.

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