Anti-fading micro-elastic business jean fabric and preparation method thereof

Abstract

The present application relates to a kind of anti-fading micro elastic business jean fabric and its preparation method, belong to the technical field of fabric.The preparation method of the business jean fabric is, using modified liquid pretreatment warp yarn, then it is dyed by rope dyeing, multiple washing, sizing, winding, obtain modified dyeing warp yarn, using cotton double spandex core yarn as weft yarn, with modified dyeing warp yarn interwoven weaving, the obtained grey cloth is one positive and one negative gas singeing after desizing, it is neutralized and washed, high-temperature cleaning, drying, plasma treatment, two dip two padding impregnation elastic color fixing finishing liquid, tentering setting, rubber blanket preshrinking treatment.The business jean fabric prepared has excellent anti-fading performance, stable micro elastic performance.

Description

Technical Field

[0001] This invention belongs to the field of fabric technology and relates to a colorfast, micro-elastic business denim fabric and its preparation method. Background Technology

[0002] Current business denim fabrics are mostly made of high-density dark twill weave and add a small amount of spandex to create a slightly elastic fabric. They abandon the traditional distressed and faded process of casual denim, resulting in a smooth and crisp fabric surface and a simple and formal style. They are widely used in light business workplace commuting attire, effectively making up for the shortcomings of traditional formal wear fabrics that are stiff and inelastic.

[0003] Current business denim fabrics still suffer from significant technical drawbacks, and existing improvement solutions have limitations. Conventional indigo and sulfur dyes adhere only to the fiber surface, resulting in high levels of loose dye. Due to the dark color requirements of business denim, heavy washing cannot remove this loose dye, leading to low wet rubbing colorfastness and a tendency to fade and stain. Traditional spandex formulations struggle to balance elasticity and crispness, resulting in elasticity degradation and surface blistering with prolonged use. Therefore, there is an urgent need to develop a manufacturing process for business denim fabrics that balances colorfastness and elasticity, addressing the multiple shortcomings of existing technologies. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a colorfast micro-elastic business denim fabric and its preparation method.

[0005] The objective of this invention can be achieved through the following technical solutions: This invention provides a method for preparing a colorfast, micro-elastic business denim fabric, the method comprising the following steps: X1. The warp yarn is pretreated with a modified liquid, then dyed with rope dye, washed multiple times, sized, and wound to obtain modified dyed warp yarn. X2. Cotton double spandex core-spun yarn is used as the weft yarn and interwoven with modified dyed warp yarn to obtain the greige fabric; X3. After the fabric is singed with gas in both directions, it is desized, washed with neutralized water, cleaned at high temperature, and dried to obtain the treated fabric. X4. The treated fabric is subjected to plasma treatment and then dipped and rubbed twice with an elastic color-fixing finishing solution to obtain the dipped fabric. X5. The impregnated fabric is stretched and shaped, and then pre-shrinked with a rubber blanket to obtain the fabric.

[0006] Preferably, the warp yarn in step X1 is 30-count pure cotton yarn; the modifying solution consists of 4-6 g / L cationic modifier, 2-4 g / L penetrant, and the remainder deionized water; the pretreatment involves immersing the warp yarn in the modifying solution at 45°C for 20-30 minutes, with a roll-off rate of 65-75%, and pre-drying at 80°C after immersion.

[0007] Preferably, the cationic modifier is selected from one or more of 3-chloro-2-hydroxypropyltrimethylammonium chloride, 2,3-epoxypropyltrimethylammonium chloride, and polyepoxychloropropane-dimethylamine.

[0008] Preferably, the penetrant is selected from one or more of penetrant JFC-1, penetrant OEP-70, and BASF XP-90.

[0009] Preferably, the dyeing process parameters are as follows: using 3-4% (owf) indigo dye, 16-20 g / L sodium hydrosulfite, 8-12 g / L caustic soda, and 4-8 g / L leveling agent, dyeing is carried out at 35-45℃, the machine speed is 18-22 m / min, the number of dyeing passes is 6, after each dyeing pass, oxidation is carried out in the air for 2-3 minutes, and after the final dyeing pass, three countercurrent water washes are performed at a water temperature of 45-55℃.

[0010] Preferably, the leveling agent is selected from one or more of leveling agent 1815, leveling agent O-25, and leveling agent O-15.

[0011] Preferably, the sizing slurry is 75-85 g / L oxidized modified starch, which is dried at 110-130℃ after sizing and then wound.

[0012] This invention uses a cationic modified liquid to pretreat pure cotton warp yarns, stabilizing the surface of cotton fiber macromolecules with cationic active groups. Utilizing electrostatic adsorption, it significantly enhances the binding strength of indigo leuco dye to the fibers, effectively improving the defects of traditional denim warp yarns such as "severe ring dyeing and large amount of surface dye accumulation." It reduces the amount of surface dye generated from the source of dye adsorption and fixation. Simultaneously, the modified pretreatment does not clog fiber pores or damage the smooth texture of the fabric surface, perfectly matching the dark, non-distressed appearance requirements of business denim. It avoids the problems of fabric whitening and pattern damage caused by traditional heavy water washing to remove surface dye, providing a pre-existing guarantee for the fabric's basic anti-fading performance.

[0013] Preferably, the cotton double spandex core-spun yarn in step X2 consists of a cotton fiber outer sheath and a double spandex elastic yarn core layer; the specifications of the double spandex elastic yarns are 40D and 70D, the feeding mass ratio of 40D spandex yarn to 70D spandex yarn is 0.8-1.2:1, the pre-stretch ratio is controlled at 2.5-3.5 times and 3.0-4.0 times respectively, and the total mass proportion of double spandex elastic yarn in the entire core-spun weft yarn is 2-4%.

[0014] Preferably, the weft yarn has a count of 20 and a twist of 900-1100 twists / meter; the interlacing weave adopts a 3 / 1 right-hand twill weave structure, the warp and weft density of the greige fabric is 120-130 threads / inch × 80-90 threads / inch, and the greige fabric weight is 9.5-11 oz; the weft yarn is steamed before winding at a temperature of 70°C for 30-50 minutes.

[0015] This invention employs a dual-specification differentiated spandex parallel core-spun weft yarn structure, combined with different pre-stretch ratios and high-temperature steaming and setting processes. The fine denier 40D spandex provides soft and immediate stretch elasticity, ensuring comfortable and unrestricted wear, while the coarse denier 70D spandex possesses excellent resistance to plastic deformation, effectively resisting the loosening and bulging problems caused by prolonged sitting and repeated stretching. The two spandex fibers complement each other, completely avoiding the defects of traditional single spandex elastic yarns such as long-term fatigue loss of elasticity and rapid decline in fabric elasticity.

[0016] Preferably, the amount of desizing enzyme used in step X3 is 1.5-2.5 g / L, the pH value is 5.5-6.5, the temperature is 60-70℃, and the stacking time is 40-50 min; the singeing temperature is 850-950℃, and the machine speed is 60-70 m / min; the neutralizing water washing working solution contains 2-4 g / L acetic acid, and the water washing temperature is 40℃; the high-temperature cleaning is two hot water washes at 80℃; and the drying is drying at 110℃ until the fabric surface moisture content is ≤5%.

[0017] Preferably, the plasma treatment in step X4 is an air plasma treatment at atmospheric pressure, 250W, and 40℃ for 2-3 minutes; the pH of the elastic color-fixing solution is 5.5, and it consists of 40-50 g / L polyurethane / acrylate core-shell composite nanoemulsion, an appropriate amount of glacial acetic acid, and the remainder deionized water; the speed of the two dips and two rolls is 30-35 m / min, and the roll pressure is 2.5-3.0 kg / cm². 2 The rolling allowance is 70-75%.

[0018] This invention introduces atmospheric pressure low-temperature air plasma directional activation treatment, which micro-etches the surface of fabric fibers to construct a nanoscale rough structure without damaging the fabric's strength or destroying its dark appearance. This significantly improves the fiber surface energy and wettability, while generating polar active groups such as hydroxyl and carboxyl groups. This process can effectively open the gaps between tightly packed yarns, solving the defect of traditional finishing that can only adhere to the fabric surface and cannot penetrate into the yarn interior, and significantly improving the adsorption capacity and penetration uniformity of the subsequent elastic color-fixing solution.

[0019] Preferably, the polyurethane / acrylate core-shell composite nanoemulsion described in step X5 is prepared by the following method: Y1. Polycarbonate diol was dehydrated under vacuum at 110℃ for 2 hours, cooled to 85℃, and isophorone diisocyanate and dibutyltin dilaurate were added and reacted for 3-4 hours. Then, 2,2-dimethylolpropionic acid, 1,4-butanediol and trimethylolpropane were added and reacted for 2-3 hours. After cooling to 40℃, triethylamine was added to neutralize for 10-20 minutes. Deionized water was added and dispersed under stirring at 1200-1800 rpm. After adding ethylenediamine aqueous solution dropwise, the chain was extended for 1-2 hours to obtain an aqueous polyurethane dispersion. Y2. Glycidyl methacrylate, N-hydroxymethylacrylamide, methyl methacrylate, butyl acrylate, divinylbenzene, sodium allyl hydroxypropyl sulfonate, sodium bicarbonate, and deionized water are mixed and emulsified at 4000-6000 rpm for 30-40 min to obtain a shell monomer pre-emulsion. Y3. Dilute the aqueous polyurethane dispersion to 8-10%, heat to 75°C, add potassium persulfate initiator accounting for 0.3-0.6% of the total mass of the shell monomer preemulsion, and uniformly add the shell monomer preemulsion over 4-5 hours to carry out seed emulsion polymerization. After the addition is complete, keep the reaction at the temperature for 2-3 hours to obtain the polyurethane / acrylate core-shell composite nanoemulsion.

[0020] Preferably, in step Y1, the mass ratio of polycarbonate diol, isophorone diisocyanate, dibutyltin dilaurate, 2,2-dimethylolpropionic acid, 1,4-butanediol, trimethylolpropane, triethylamine, ethylenediamine aqueous solution, and deionized water is 55-65:20-24:0.05-0.15:2-5:1.8-2.6:0.6-1:2.5-3.5:15-21:110-130; and the mass concentration of the ethylenediamine aqueous solution is 8-12 wt%.

[0021] Preferably, the mass ratio of glycidyl methacrylate, N-hydroxymethylacrylamide, methyl methacrylate, butyl acrylate, divinylbenzene, sodium allyl hydroxypropyl sulfonate, sodium bicarbonate, and deionized water in step Y2 is 8-12:3-5:10-15:4-6:1-2:0.5-1:0.1-0.3:60-80.

[0022] Preferably, the mass ratio of the aqueous polyurethane dispersion to the shell monomer preemulsion in step Y3 is 1:0.8-1.5.

[0023] This invention provides a polyurethane / acrylate core-shell composite nanoemulsion. By embedding the nanoemulsion into fiber gaps and penetrating into the yarn, it is initially anchored by intermolecular forces. The epoxy groups and N-hydroxymethyl active groups enriched in the emulsion shell undergo direct ring-opening and bonding with the hydroxyl groups of the cotton fibers during subsequent finishing processes. The N-hydroxymethyl groups undergo thermally induced self-dehydration condensation crosslinking at high temperatures, thereby forming a crosslinked protective film in the fiber's internal pores and surface. On one hand, the crosslinked film completely encapsulates and seals residual free indigo dye that cannot be washed away from the fiber surface and yarn gaps, restricting the dissolution and migration of dye during washing and friction. On the other hand, the crosslinked bonds anchor the protective film entirely to the fiber matrix, effectively preventing the color-fixing auxiliaries from detaching and becoming ineffective, achieving long-lasting color locking. Meanwhile, the high elongation polycarbonate polyurethane core of the emulsion forms a flexible and elastic protective network after curing, which covers cotton fibers and dual-specification spandex filaments. This effectively buffers external force stretching and friction loss, inhibits spandex thermal aging and plastic deformation, and thus maintains the fabric's uniform and stable micro-elasticity, giving the fabric both long-lasting colorfastness and stable micro-elasticity.

[0024] Preferably, the setting temperature of the stretching and setting in step X5 is 150-160℃, the machine speed is 35-45m / min, the hot air circulation speed is 10-15m / s, the time is 100-150s, and the setting liquid used for setting consists of 18-22g / L softener, 2.5-3.5g / L phenolic antioxidant, 1.5-2.5g / L anti-slip agent, and the balance deionized water.

[0025] Preferably, the softener is selected from one or more of polyethylene glycol PEG-6000, polyethylene glycol PEG-600, and softener SG-100.

[0026] Preferably, the phenolic antioxidant is selected from one or more of antioxidant 1098, antioxidant 245, and antioxidant 330.

[0027] Preferably, the antislip agent is selected from one or more of antislip agent YZ-82, antislip agent LT-ZY012, and antislip agent SSG300.

[0028] Preferably, the pre-shrinking process uses a rubber blanket pre-shrinking machine with a warp shrinkage rate of 3-4% and a machine speed of 30-35 m / min.

[0029] Finally, this invention utilizes stretching and setting to transform the physically adsorbed nano-protective film into a more stable cured film, significantly improving its water resistance and abrasion resistance. Furthermore, by combining it with mechanical pre-shrinking treatment using a rubber blanket, the potential shrinkage stress of the cotton fibers is released in advance, further stabilizing the fabric's shape and appearance quality.

[0030] The beneficial effects of this invention are: This invention creatively provides a polyurethane / acrylate core-shell composite nanoemulsion, which differs from ordinary single-component additives that are simply compounded, only adhere to the surface, and are prone to detachment and failure. This invention forms a multi-level anti-fading mechanism of base chemical bond color fixation + internal and external double-encapsulation color locking. Specifically, pre-cationic modification makes the inside and surface of cotton fibers positively charged, firmly adsorbing and bonding the indigo dye leuco form to the inside of the fiber from the source, reducing free floating color. Then, plasma etching is used to construct micropores on the fiber surface and generate a large number of hydroxyl and carboxyl active groups, breaking the dense structure of the fabric. This allows the nanoemulsion particles to be deeply embedded in the fiber gaps and penetrate into the yarn. They are initially anchored by intermolecular forces and form a cross-linked protective film in the fiber pores and on the surface. Finally, shaping and pre-shrinking treatment effectively endow the fabric with the dual properties of anti-fading and stable micro-elasticity.

[0031] This invention provides a method for preparing business denim fabric. Through a process of "reducing floating color at the source - pretreatment to clean the substrate - plasma activation - core-shell emulsion film formation to lock in color and protect elasticity - curing and stabilizing", the fabric achieves excellent anti-fading performance and stable micro-elasticity without using heavy washing and bleaching processes that would damage its business appearance. This method has certain application prospects. Detailed Implementation

[0032] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with embodiments, is provided below.

[0033] The 30-count pure cotton yarn comes from Qingdao Xinyutai Textile Co., Ltd.; the 40D and 70D spandex yarns come from Wuxi Sanjiang New Material Fiber Co., Ltd.; and the oxidized modified starch comes from Qinyang Xinxing Chemical Co., Ltd.

[0034] The fiber / yarn materials used in all embodiments and comparative examples of this invention have been treated with conventional steps such as opening before processing, according to the requirements of the corresponding materials; other materials and reagents used in all embodiments and comparative examples of this invention can be obtained commercially unless otherwise specified.

[0035] The preparation methods of the colorfast, micro-elastic business denim fabrics described in Examples 1-3 all include the following steps: X1. The warp yarn is pretreated with a modified liquid, then dyed with rope dye, washed multiple times, sized, and wound to obtain modified dyed warp yarn. X2. Cotton double spandex core-spun yarn is used as the weft yarn and interwoven with modified dyed warp yarn to obtain the greige fabric; X3. After the fabric is singed with gas in both directions, it is desized, washed with neutralized water, cleaned at high temperature, and dried to obtain the treated fabric. X4. The treated fabric is subjected to plasma treatment and then dipped and rubbed twice with an elastic color-fixing finishing solution to obtain the dipped fabric. X5. The impregnated fabric is stretched and shaped, and then pre-shrinked with a rubber blanket to obtain the fabric. The dyeing process parameters in step X1 are as follows: 3.5% (owf) indigo dye, 18 g / L sodium hydrosulfite, 10 g / L caustic soda, and 6 g / L leveling agent O-25 are used for dyeing at 40℃, with a machine speed of 20 m / min, 6 dyeing passes, and an air oxidation period of 2.5 min after each dyeing pass. After the final dyeing pass, the product undergoes three countercurrent water washes at a temperature of 50℃. The sizing agent is 80 g / L oxidized modified starch, which is dried at 120℃ after sizing and then wound. The cotton double spandex core-spun yarn in step X2 consists of a cotton fiber outer layer and a double spandex elastic yarn core layer; the weft yarn has a count of 20 and a twist of 1000 twists / meter; the interlacing weave adopts a 3 / 1 right twill weave structure, the warp and weft density of the greige fabric is 125 threads / inch × 85 threads / inch, and the greige fabric weight is 10oz; the weft yarn is steamed before winding at a temperature of 70℃ for 40 minutes. In step X3, the desizing enzyme dosage is 2 g / L, the pH value is 6, the temperature is 65℃, and the stacking time is 45 min; the singeing temperature is 900℃, and the machine speed is 65 m / min; the neutralization water washing working solution contains 3 g / L acetic acid, and the water washing temperature is 40℃; the high-temperature cleaning is two hot water washes at 80℃; the drying is done at 110℃ until the fabric surface moisture content is ≤5%. The pre-shrinking process described in step X5 uses a rubber blanket pre-shrinking machine with a warp shrinkage rate of 3.5% and a machine speed of 32m / min.

[0036] Example 1

[0037] In step X1 of this embodiment, the warp yarn is 30-count pure cotton yarn; the modification solution consists of 5g / L cationic modifier (3-chloro-2-hydroxypropyltrimethylammonium chloride), 3g / L penetrant (penetrant JFC-1), and the remainder is deionized water; the pretreatment involves immersing the warp yarn in the modification solution at 45°C for 25 minutes, with a roll-off rate of 70%, and pre-drying at 80°C after immersion. The specifications of the double spandex elastic yarns mentioned in step X2 are 40D and 70D, respectively. The feed mass ratio of 40D spandex yarn to 70D spandex yarn is 1:1, and the pre-stretch ratio is controlled at 3.0 times and 3.5 times, respectively. The total mass proportion of double spandex elastic yarns in the entire core-spun weft yarn is 3%. Step X4 involves plasma treatment at atmospheric pressure, 250W, and 40°C for 2.5 minutes; the elastic color-fixing solution has a pH of 5.5 and is composed of 45 g / L polyurethane / acrylate core-shell composite nanoemulsion, a suitable amount of glacial acetic acid, and the remainder deionized water; the two-dip and two-roll process involves a machine speed of 32 m / min and a roll pressure of 2.7 kg / cm². 2 The rolling surplus rate was 73%. The polyurethane / acrylate core-shell composite nanoemulsion described in step X5 was prepared by the following method: Y1. Polycarbonate diol was vacuum dehydrated at 110℃ for 2 hours, then cooled to 85℃ and isophorone diisocyanate and dibutyltin dilaurate were added and reacted for 3.5 hours. Then, 2,2-dimethylolpropionic acid, 1,4-butanediol, and trimethylolpropane were added and reacted for 2.5 hours. After cooling to 40℃, triethylamine was added for neutralization for 15 minutes. The mixture was then dispersed in deionized water under stirring at 1500 rpm. After dropwise addition of ethylenediamine aqueous solution, chain extension was performed for 1.5 hours to obtain an aqueous polyurethane dispersion. The mass ratio of polycarbonate diol, isophorone diisocyanate, dibutyltin dilaurate, 2,2-dimethylolpropionic acid, 1,4-butanediol, trimethylolpropane, triethylamine, ethylenediamine aqueous solution, and deionized water was 60:22:0.1:3.5:2.2:0.8:3:18:120; the mass concentration of the ethylenediamine aqueous solution was 10 wt%. Y2. Glycidyl methacrylate, N-hydroxymethylacrylamide, methyl methacrylate, butyl acrylate, divinylbenzene, sodium allyl hydroxypropyl sulfonate, sodium bicarbonate, and deionized water were mixed in a mass ratio of 10:4:12.5:5:1.5:0.75:0.2:70 and emulsified at 5000 rpm for 35 min to obtain a shell monomer pre-emulsion. Y3. Dilute the aqueous polyurethane dispersion to 9%, heat to 75°C, add potassium persulfate initiator accounting for 0.45% of the total mass of monomers in the shell monomer preemulsion, and uniformly add the shell monomer preemulsion dropwise over 4.5 hours to carry out seed emulsion polymerization. The mass ratio of the aqueous polyurethane dispersion to the shell monomer preemulsion is 1:1.1. After the dropwise addition is complete, keep the reaction at the temperature for 2.5 hours to obtain the polyurethane / acrylate core-shell composite nanoemulsion. The setting temperature for the stretching and setting process described in step X5 is 150℃, the machine speed is 40m / min, the hot air circulation speed is 12m / s, and the time is 120s. The setting solution used for setting consists of 20g / L softener (polyethylene glycol PEG-6000), 3g / L phenolic antioxidant (antioxidant 1098), 2g / L anti-slip agent (anti-slip agent YZ-82), and the balance deionized water.

[0038] Example 2

[0039] In step X1 of this embodiment, the warp yarn is 30-count pure cotton yarn; the modification solution consists of 4 g / L cationic modifier (2,3-epoxypropyltrimethylammonium chloride), 2 g / L penetrant (penetrant OEP-70), and the remainder is deionized water; the pretreatment involves immersing the warp yarn in the modification solution at 45°C for 30 min, with a roll-off rate of 75%, and pre-drying at 80°C after immersion. The specifications of the double spandex elastic yarns mentioned in step X2 are 40D and 70D, respectively. The feed mass ratio of 40D spandex yarn to 70D spandex yarn is 0.8:1, and the pre-stretch ratio is controlled at 2.5 times and 3.0 times, respectively. The total mass proportion of double spandex elastic yarns in the entire core-spun weft yarn is 2%. Step X4 describes plasma treatment as air plasma treatment at atmospheric pressure, 250W, and 40℃ for 2 minutes; the elastic color-fixing solution is prepared by adjusting the pH of 30g / L polyurethane / acrylate core-shell composite nanoemulsion to 5.5 with glacial acetic acid and then adding the remaining deionized water; the two-dip and two-roll process has a machine speed of 30m / min and a roll pressure of 2.5kg / cm. 2 The rolling surplus rate was 75%. The polyurethane / acrylate core-shell composite nanoemulsion described in step X5 was prepared by the following method: Y1. Polycarbonate diol was vacuum dehydrated at 110℃ for 2 hours, then cooled to 85℃ and isophorone diisocyanate and dibutyltin dilaurate were added and reacted for 3 hours. 2,2-dimethylolpropionic acid, 1,4-butanediol, and trimethylolpropane were added and reacted for 2 hours. After cooling to 40℃, triethylamine was added for neutralization for 10 minutes. The mixture was then dispersed in deionized water under stirring at 1200 rpm. After dropwise addition of ethylenediamine aqueous solution, chain extension was performed for 1 hour to obtain an aqueous polyurethane dispersion. The mass ratio of polycarbonate diol, isophorone diisocyanate, dibutyltin dilaurate, 2,2-dimethylolpropionic acid, 1,4-butanediol, trimethylolpropane, triethylamine, ethylenediamine aqueous solution, and deionized water was 55:20:0.05:2:1.8:0.6:2.5:15:110; the mass concentration of the ethylenediamine aqueous solution was 8 wt%. Y2. Glycidyl methacrylate, N-hydroxymethylacrylamide, methyl methacrylate, butyl acrylate, divinylbenzene, sodium allyl hydroxypropyl sulfonate, sodium bicarbonate, and deionized water were mixed in a mass ratio of 8:3:10:4:1:0.5:0.1:60 and emulsified at 4000 rpm for 40 min to obtain a shell monomer pre-emulsion. Y3. Dilute the aqueous polyurethane dispersion to 8%, heat to 75°C, add potassium persulfate initiator accounting for 0.3% of the total mass of the shell monomer preemulsion, and uniformly add the shell monomer preemulsion dropwise over 4 hours to carry out seed emulsion polymerization. The mass ratio of the aqueous polyurethane dispersion to the shell monomer preemulsion is 1:0.8. After the dropwise addition is completed, keep the reaction at the temperature for 2 hours to obtain the polyurethane / acrylate core-shell composite nanoemulsion. The setting temperature for the stretching and setting process described in step X5 is 150℃, the machine speed is 35m / min, the hot air circulation speed is 10m / s, and the time is 150s. The setting solution used for setting consists of 18g / L softener (polyethylene glycol PEG-600), 2.5g / L phenolic antioxidant (antioxidant 245), 1.5g / L anti-slip agent (anti-slip agent LT-ZY012), and the balance deionized water.

[0040] Example 3

[0041] In step X1 of this embodiment, the warp yarn is 30-count pure cotton yarn; the modification solution consists of 6g / L cationic modifier (polyepoxychloropropane-dimethylamine), 4g / L penetrant (BASF XP-90), and the remainder is deionized water; the pretreatment involves immersing the warp yarn in the modification solution at 45°C for 20 minutes, with a roll-off rate of 65%, and pre-drying at 80°C after immersion. The specifications of the double spandex elastic yarns mentioned in step X2 are 40D and 70D, respectively. The feed mass ratio of 40D spandex yarn to 70D spandex yarn is 1.2:1, and the pre-stretch ratio is controlled at 3.5 times and 4.0 times, respectively. The total mass proportion of double spandex elastic yarns in the entire core-spun weft yarn is 4%. Step X4 involves plasma treatment at atmospheric pressure, 250W, and 40°C for 3 minutes; the elastic color-fixing solution has a pH of 5.5 and is composed of 50 g / L polyurethane / acrylate core-shell composite nanoemulsion, a suitable amount of glacial acetic acid, and the remainder deionized water; the two-dip and two-roll process has a machine speed of 35 m / min and a roll pressure of 3.0 kg / cm². 2 The rolling surplus rate is 70%; The polyurethane / acrylate core-shell composite nanoemulsion described in step X5 was prepared by the following method: Y1. Polycarbonate diol was vacuum dehydrated at 110℃ for 2 hours, then cooled to 85℃ and isophorone diisocyanate and dibutyltin dilaurate were added and reacted for 4 hours. 2,2-dimethylolpropionic acid, 1,4-butanediol, and trimethylolpropane were added and reacted for 3 hours. After cooling to 40℃, triethylamine was added for neutralization for 20 minutes. The mixture was then dispersed in deionized water under stirring at 1800 rpm. After dropwise addition of ethylenediamine aqueous solution, chain extension was performed for 2 hours to obtain an aqueous polyurethane dispersion. The mass ratio of polycarbonate diol, isophorone diisocyanate, dibutyltin dilaurate, 2,2-dimethylolpropionic acid, 1,4-butanediol, trimethylolpropane, triethylamine, ethylenediamine aqueous solution, and deionized water was 65:24:0.15:5:2.6:1:3.5:21:130; the mass concentration of the ethylenediamine aqueous solution was 12 wt%. Y2. Glycidyl methacrylate, N-hydroxymethylacrylamide, methyl methacrylate, butyl acrylate, divinylbenzene, sodium allyl hydroxypropyl sulfonate, sodium bicarbonate, and deionized water were mixed in a mass ratio of 12:5:15:6:2:1:0.3:80 and emulsified at 6000 rpm for 30 min to obtain a shell monomer pre-emulsion. Y3. Dilute the aqueous polyurethane dispersion to 10%, heat to 75°C, add potassium persulfate initiator accounting for 0.6% of the total mass of monomers in the shell monomer preemulsion, and uniformly add the shell monomer preemulsion dropwise over 5 hours to carry out seed emulsion polymerization. The mass ratio of the aqueous polyurethane dispersion to the shell monomer preemulsion is 1:1.5. After the dropwise addition is complete, keep the reaction at the temperature for 3 hours to obtain the polyurethane / acrylate core-shell composite nanoemulsion. The setting temperature for the stretching and setting process described in step X5 is 160℃, the machine speed is 45m / min, the hot air circulation speed is 15m / s, and the time is 100s. The setting solution used for setting consists of 22g / L softener (softener SG-100), 3.5g / L phenolic antioxidant (antioxidant 330), 2.5g / L anti-slip agent (anti-slip agent SSG300), and the balance deionized water.

[0042] Comparative Example 1 The difference from Example 1 is that the warp yarns are not pretreated with the modifying liquid, while the other conditions remain the same as in Example 1.

[0043] Comparative Example 2 Compared with Example 1, the difference is that a 40D spandex core layer is used instead of a double spandex elastic yarn core layer, while other conditions remain the same as in Example 1.

[0044] Comparative Example 3 Compared with Example 1, the difference is that a 70D spandex core layer is used instead of a double spandex elastic yarn core layer, while other conditions remain the same as in Example 1.

[0045] Comparative Example 4 Compared with Example 1, the difference is that the plasma treatment in step X4 is removed, while the other conditions remain the same as in Example 1.

[0046] Comparative Example 5 Compared with Example 1, the difference is that the polycarbonate diol in step Y1 is replaced with a polyether diol, while the other conditions remain the same as in Example 1.

[0047] Comparative Example 6 Compared with Example 1, the difference is that, keeping other conditions unchanged, an equal amount of polyurethane / acrylate composite emulsion is used to replace the polyurethane / acrylate core-shell composite nanoemulsion. The preparation method of the polyurethane / acrylate core-shell composite nanoemulsion is to eliminate the seed emulsion polymerization step in the original preparation process of polyurethane / acrylate core-shell composite nanoemulsion, and to simply and rapidly stir and physically blend the aqueous polyurethane dispersion with the acrylate emulsion of the same composition to obtain the blended composite emulsion.

[0048] Comparative Example 7 Compared with Example 1, the difference is that an equal amount of TY2-17 turquoise blue fixing agent (padding dosage of 45 g / L) was used instead of the elastic fixing solution, while other conditions remained the same as in Example 1.

[0049] To test the colorfastness and elasticity of the fabric in practical applications, the commercial denim fabrics prepared in Examples 1-3 and Comparative Examples 1-7 were used as samples. The colorfastness of the samples was tested according to GB / T 3920-2024, and the test results are recorded in Table 1 below. The elasticity of the samples was tested according to GB / T 21655.2-2019. Each group of samples required 3 parallel tests, and the average test results were recorded in Table 1 below.

[0050] Table 1

[0051] As shown in Table 1, the commercial denim fabric prepared by this invention has excellent anti-fading properties and stable micro-elasticity.

[0052] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any indirect modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A method for preparing a colorfast, micro-elastic business denim fabric, characterized in that, The preparation method of the colorfast, micro-elastic business denim fabric includes the following steps: X1. The warp yarn is pretreated with a modified liquid, then dyed with rope dye, washed multiple times, sized, and wound to obtain modified dyed warp yarn. X2. Cotton double spandex core-spun yarn is used as the weft yarn and interwoven with modified dyed warp yarn to obtain the greige fabric; X3. After the fabric is singed with gas in both directions, it is desized, washed with neutralized water, cleaned at high temperature, and dried to obtain the treated fabric. X4. The treated fabric is subjected to plasma treatment and then dipped and rubbed twice with an elastic color-fixing finishing solution to obtain the dipped fabric. X5. The impregnated fabric is stretched and shaped, and then pre-shrinked with a rubber blanket to obtain the fabric.

2. The method for preparing the colorfast, micro-elastic business denim fabric according to claim 1, characterized in that, The warp yarn in step X1 is 30-count pure cotton yarn; the modification solution consists of 4-6 g / L cationic modifier, 2-4 g / L penetrant, and the remainder is deionized water; the pretreatment involves immersing the warp yarn in the modification solution at 45°C for 20-30 minutes, with a roll-off rate of 65-75%, and pre-drying at 80°C after immersion.

3. The method for preparing the colorfast, micro-elastic business denim fabric according to claim 1, characterized in that, The cotton double spandex core-spun yarn described in step X2 consists of a cotton fiber outer sheath and a double spandex elastic yarn core layer; the specifications of the double spandex elastic yarns are 40D and 70D, the feeding mass ratio of 40D spandex yarn to 70D spandex yarn is 0.8-1.2:1, the pre-stretch ratio is controlled at 2.5-3.5 times and 3.0-4.0 times respectively, and the total mass proportion of double spandex elastic yarn in the entire core-spun weft yarn is 2-4%.

4. The method for preparing the colorfast, micro-elastic business denim fabric according to claim 1, characterized in that, Step X4 involves plasma treatment at atmospheric pressure, 250W, and 40℃ for 2-3 minutes; the elastic color-fixing solution has a pH of 5.5 and consists of 40-50 g / L polyurethane / acrylate core-shell composite nanoemulsion, an appropriate amount of glacial acetic acid, and the remainder deionized water; the two-dip and two-roll process involves a machine speed of 30-35 m / min and a roll pressure of 2.5-3.0 kg / cm². 2 The rolling allowance is 70-75%.

5. The method for preparing the colorfast, micro-elastic business denim fabric according to claim 1, characterized in that, The polyurethane / acrylate core-shell composite nanoemulsion described in step X5 was prepared by the following method: Y1. Polycarbonate diol was dehydrated under vacuum at 110℃ for 2 hours, then cooled to 85℃ and isophorone diisocyanate and dibutyltin dilaurate were added and reacted for 3-4 hours. 2,2-dimethylolpropionic acid, 1,4-butanediol and trimethylolpropane were added and reacted for 2-3 hours. After cooling to 40℃, triethylamine was added to neutralize for 10-20 minutes. Deionized water was added and dispersed under stirring at 1200-1800 rpm. After adding ethylenediamine aqueous solution dropwise, the chain was extended for 1-2 hours to obtain an aqueous polyurethane dispersion. Y2. Glycidyl methacrylate, N-hydroxymethylacrylamide, methyl methacrylate, butyl acrylate, divinylbenzene, sodium allyl hydroxypropyl sulfonate, sodium bicarbonate, and deionized water are mixed and emulsified at 4000-6000 rpm for 30-40 min to obtain a shell monomer pre-emulsion. Y3. Dilute the aqueous polyurethane dispersion to 8-10%, heat to 75°C, add potassium persulfate initiator accounting for 0.3-0.6% of the total mass of the shell monomer preemulsion, and uniformly add the shell monomer preemulsion over 4-5 hours to carry out seed emulsion polymerization. After the addition is complete, keep the reaction at the temperature for 2-3 hours to obtain the polyurethane / acrylate core-shell composite nanoemulsion.

6. The method for preparing a colorfast, micro-elastic business denim fabric according to claim 5, characterized in that, In step Y1, the mass ratio of polycarbonate diol, isophorone diisocyanate, dibutyltin dilaurate, 2,2-dimethylolpropionic acid, 1,4-butanediol, trimethylolpropane, triethylamine, ethylenediamine aqueous solution, and deionized water is 55-65:20-24:0.05-0.15:2-5:1.8-2.6:0.6-1:2.5-3.5:15-21:110-130; the mass concentration of the ethylenediamine aqueous solution is 8-12 wt%.

7. The method for preparing a colorfast, micro-elastic business denim fabric according to claim 5, characterized in that, The mass ratio of glycidyl methacrylate, N-hydroxymethylacrylamide, methyl methacrylate, butyl acrylate, divinylbenzene, sodium allyl hydroxypropyl sulfonate, sodium bicarbonate, and deionized water in step Y2 is 8-12:3-5:10-15:4-6:1-2:0.5-1:0.1-0.3:60-80.

8. The method for preparing a colorfast, micro-elastic business denim fabric according to claim 5, characterized in that, The mass ratio of the aqueous polyurethane dispersion to the shell monomer preemulsion in step Y3 is 1:0.8-1.

5.

9. The method for preparing a colorfast, micro-elastic business denim fabric according to claim 1, characterized in that, The setting temperature for the stretching and setting process described in step X5 is 150-160℃, the machine speed is 35-45m / min, the hot air circulation speed is 10-15m / s, and the time is 100-150s. The setting solution used for setting consists of 18-22g / L softener, 2.5-3.5g / L phenolic antioxidant, 1.5-2.5g / L anti-slip agent, and the remainder is deionized water.

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