A bio-based liquid reducing cleaning agent and its application method

Abstract

The application discloses a kind of liquid reductive cleaning agent of biomass type and its application method.The cleaning agent includes hydrating reducing sugar 30-35% by weight percentage, bovine fat alkyl ethoxylated amine 1-2%, and the rest is water;Wherein the hydrating reducing sugar is derived from including glucose, fructose, maltose, lactose, gluconic acid, sodium gluconate and its hydrate one or more;The pH value of 10% aqueous solution of the cleaning agent is 7-9 at 20 DEG C.The total biomass content of the cleaning agent is >90%, and the biodegradability is >90% in 28 days, and the COD of 5g / L aqueous solution is <700 ppm, does not contain sulfide, and the flash point is >100 DEG C.In application, the cleaning agent is used for reductive cleaning of polyester fabric after disperse dye dyeing or stripping process of dyeing defect fabric.Compared with traditional sodium hydrosulfite, the application can reduce COD by >50%, reduce carbon emission by >90%, has no safety hazard, and the reduction washing fastness and stripping effect are equivalent or better, to realize green printing and dyeing.

Description

Technical Field

[0001] This invention relates to the field of textile printing and dyeing technology, and more specifically, to a bio-based liquid reducing cleaning agent for post-dyeing treatment of polyester and its blended fabrics, and an application method using the cleaning agent for reducing cleaning and color stripping treatment. Background Technology

[0002] The textile printing and dyeing industry is a typical high-water-consuming and high-polluting industry. In the dyeing process of synthetic fibers such as polyester, disperse dyes are typically used for high-temperature and high-pressure dyeing. After dyeing, a large amount of unfixed disperse dye (i.e., floating dye) often remains on the fiber surface. This floating dye severely affects the color fastness (such as wash fastness and rubbing fastness) and color brightness of the dyed fabric. Therefore, reduction cleaning (post-treatment) is necessary to remove the floating dye.

[0003] Traditional reduction cleaning processes commonly use sodium dithionite (CAS: 7775-14-6) as a reducing agent. However, sodium dithionite has several inherent drawbacks: 1. Significant Environmental Hazards: The production and use of sodium hydrosulfite generate large amounts of wastewater with high chemical oxygen demand (COD). Its decomposition products and byproducts (such as sulfites and thiosulfates), as well as unreacted sodium hydrosulfite, significantly increase the wastewater treatment load. The COD concentration of residual sodium hydrosulfite solution is typically above 1500-1600 ppm, placing enormous pressure on wastewater treatment plants. Simultaneously, its sulfur content may cause foul odors and ecotoxicity in water bodies, harming aquatic life.

[0004] 2. High Safety Hazards: Sodium hydrosulfite is a powdery solid that is flammable and explosive. It readily decomposes and spontaneously combusts when exposed to moisture, heat, or air, requiring stringent storage and transportation procedures. In dyeing and printing workshops, sodium hydrosulfite dust not only poses an explosion risk but also damages the respiratory system of workers, potentially leading to occupational diseases with prolonged exposure. Furthermore, the sulfur dioxide and other gases released during the decomposition of sodium hydrosulfite have an irritating odor, worsening the working environment in the workshop.

[0005] 3. Poor process stability: The reducing power of sodium hydrosulfite decreases significantly with prolonged storage time and exposure to humid air, resulting in large differences in dyeing effects between batches (batch variation) and making quality control difficult. High temperatures and multiple water washes are required during use, leading to high energy and water consumption. Furthermore, sodium hydrosulfite exhibits varying reduction and cleaning effects on disperse dyes with different structural types (such as azo, anthraquinone, and heterocyclic dyes), indicating a need to improve its versatility.

[0006] 4. High carbon emissions: The production of sodium hydrosulfite originates from the petrochemical route, resulting in a high carbon footprint throughout its entire life cycle. In the context of global "dual carbon" goals, the use of sodium hydrosulfite is detrimental to the green transformation and sustainable development of dyeing and printing enterprises.

[0007] To overcome the aforementioned drawbacks of sodium hydrosulfite, the industry has attempted to develop various alternatives, such as thiourea dioxide and environmentally friendly reducing cleaning agents. However, existing alternatives still suffer from insufficient reducing capacity, high costs, or the presence of environmentally unfriendly components. Therefore, developing a truly green, safe, efficient, and cost-effective liquid reducing cleaning agent, and establishing corresponding application processes, has become an urgent need within the industry. Summary of the Invention

[0008] This invention aims to provide an environmentally friendly and safe bio-based liquid reducing cleaning agent, namely Reduction RCOPlus, which uses hydrated reducing sugar as the main active component, combined with tallow alkyl ethoxyamine as a synergistic dispersant, water as a solvent, and is applied under weakly alkaline conditions with a pH of 7-9. It also provides an application method for this cleaning agent, achieving excellent reducing cleaning and color stripping effects by optimizing the reduction cleaning and color stripping process parameters, thus solving the problems of poor safety, serious pollution, and high carbon emissions associated with traditional sodium hydrosulfite.

[0009] To achieve the above objectives, the present invention provides the following technical solution: A bio-based liquid reducing cleaning agent, by weight percentage, comprises 30-35% hydrated reducing sugar, 1-2% tallow alkyl ethoxylate, and the remainder is water; wherein the hydrated reducing sugar is a reducing sugar substance derived from plant-based raw materials, including one or more of glucose, fructose, maltose, lactose, gluconic acid, sodium gluconate, and their hydrates; a 10% aqueous solution of the bio-based liquid reducing cleaning agent has a pH value of 7-9 at 20°C.

[0010] In this invention, hydrated reducing sugar is the main active component. Its mechanism of action is as follows: under alkaline conditions, hydrated reducing sugar can undergo an enediolization reaction to generate a highly reducing intermediate, thereby effectively reducing and decomposing the chromophores such as azo and anthraquinone groups in disperse dye molecules, or reducing the floating dye adsorbed on the fiber surface to a soluble leuco form, making it easy to remove by washing with water. Compared with sodium hydrosulfite, hydrated reducing sugar is derived from plant resources, is renewable and biodegradable, and does not contain sulfur, significantly improving its environmental friendliness.

[0011] In this invention, tallow alkyl ethoxylate (CAS No.: 61791-26-2) is used as a synergistic dispersant. Its functions are twofold: firstly, tallow alkyl ethoxylate possesses excellent wetting, penetrating, and emulsifying dispersion capabilities, promoting the penetration of the cleaning agent into the fiber interior and rapidly dispersing the loose dye stripped from the fiber surface in the treatment bath, preventing re-contamination of the fiber; secondly, the weakly cationic nature of tallow alkyl ethoxylate helps it bind with negatively charged dye molecules, improving the removal efficiency of loose dye. The content of tallow alkyl ethoxylate is controlled between 1-2%, which fully utilizes its synergistic effect while avoiding the irritation problems caused by excessively high concentrations (the actual usable concentration after dilution is extremely low, and the risk is negligible).

[0012] In this invention, water serves as both a solvent and a carrier, dissolving or dispersing hydrated reducing sugars and tallow alkyl ethoxylates into a homogeneous liquid system. The liquid form avoids dust generation, improves operational safety, and facilitates automated dosing.

[0013] Furthermore, the bio-based liquid reducing cleaning agent is applied under weakly alkaline conditions with a pH of 7-9. Firstly, hydrated reducing sugars are stable and exhibit optimal reducing activity under weakly alkaline conditions; if the pH is too low, the reducing capacity decreases, and if the pH is too high, side reactions or fabric damage may occur. Secondly, the weakly alkaline conditions match the conventional processes for polyester dyeing post-treatment, eliminating the need for additional pH adjustments. Thirdly, the weakly alkaline conditions of pH 7-9 are less corrosive to operators and equipment, resulting in higher safety. It should be noted that this pH range refers to the pH value of the treatment bath during application, not the pH value of the undiluted cleaning agent. In practical applications, this can be achieved by adding an alkaline adjuster or utilizing the inherent weak alkalinity of the cleaning agent itself.

[0014] Furthermore, the bio-based liquid reducing cleaning agent satisfies one or more of the following characteristics: a) Total biomass content greater than 90%; b) Biodegradability greater than 90% after 28 days; c) The chemical oxygen demand (COD) of a 5 g / L aqueous solution is less than 700 ppm; d) Contains no sulfides; e) Flash point above 100℃, does not spontaneously combust.

[0015] These characteristics collectively constitute the green and environmentally friendly attributes of the cleaning agent of this invention. A total biomass content greater than 90% means that the vast majority of the carbon in the product comes from renewable plant resources, rather than fossil fuels, thus significantly reducing the carbon footprint. Calculations show that the total life-cycle carbon emissions of the cleaning agent of this invention can be reduced by more than 90% compared to traditional sodium hydrosulfite. High biodegradability (>90%) ensures that the product can be rapidly decomposed by microorganisms in the natural environment after use, without causing persistent pollution. Low COD (<700ppm) means that the product itself places a smaller load on wastewater treatment systems and will not increase COD emissions during use. The absence of sulfides completely eliminates the risk of sulfur pollution, avoiding foul odors and ecotoxicity in water bodies. The high flash point and non-self-ignition properties ensure the safety of the product during storage and transportation, completely solving the safety hazards of the flammability and explosiveness of sodium hydrosulfite.

[0016] The present invention also provides a method for applying the bio-based liquid reducing cleaning agent.

[0017] Application Method 1: Reduction Cleaning Process The bio-based liquid reducing cleaning agent is used to reduce and clean polyester fabrics dyed with disperse dyes.

[0018] Specifically, the process conditions for the reduction cleaning are as follows: The dosage of the biomass-based liquid reducing cleaning agent is 2.0-5.0 g / L; The dosage of the alkaline regulator is 2.0-4.0 g / L; The bath ratio is 1:10 to 1:20; The processing temperature is 80-85℃; The processing time is 15-25 minutes.

[0019] The alkalinity regulator is selected from one or more of sodium hydroxide, potassium hydroxide, and sodium carbonate, preferably a 45% sodium hydroxide solution.

[0020] The design principle of the reduction cleaning process of this invention is as follows: In the alkaline environment (pH 7-9) provided by the alkaline regulator, hydrated reducing sugars undergo an enediolization reaction to generate strong reducing substances, reducing the unfixed disperse dyes on the fiber surface to soluble leuco forms. Simultaneously, tallow alkyl ethoxylates exert their wetting, penetrating, and dispersing effects, promoting the reaction and preventing dye re-contamination. Optimal cleaning results are achieved by reacting at 80-85℃ for 15-25 minutes. When the cleaning agent dosage is below 2.0 g / L, the reducing capacity is insufficient; above 5.0 g / L, economic efficiency decreases and over-reduction may lead to light color. When the alkaline regulator dosage is below 2.0 g / L, the pH is insufficient, resulting in incomplete reduction; above 4.0 g / L, it may damage the fibers. A liquor ratio of 1:10 to 1:20 is the operating range of conventional dyeing equipment.

[0021] Optionally, the post-treatment process of this reduction cleaning process is simplified: after draining, only a 10-minute hot water wash (60℃) and a 10-minute cold water wash are required for drying, without the need for a separate neutralization step (because the treatment bath itself has a moderate pH and low residual alkali). Compared with the sodium hydrosulfite process (which usually requires five steps: draining, hot water washing, neutralization, warm water washing, and cold water washing), it can save 20-30% of water, with significant energy-saving effect.

[0022] Application Method Two: Color Peeling Process In the stripping process of dyed defective fabrics, the bio-based liquid reducing cleaning agent and alkaline conditioner are added to the treatment solution to strip the fabric. The alkaline conditioner is selected from one or more of sodium hydroxide, potassium hydroxide, and sodium carbonate, preferably a 45% sodium hydroxide solution.

[0023] Specifically, when the object of the color stripping treatment is a polyester fabric, the process conditions are as follows: The dosage of the biomass-based liquid reducing cleaning agent is 5.0-10.0 g / L; The dosage of the alkaline regulator is 5.0-8.0 g / L; The bath ratio is 1:10 to 1:20; The processing temperature is 120-135℃; The processing time is 30-60 minutes.

[0024] When the object of the stripping treatment is cotton or nylon fabric, the process conditions are as follows: The dosage of the biomass-based liquid reducing cleaning agent is 5.0-10.0 g / L; The dosage of the alkaline regulator is 5.0-8.0 g / L; The bath ratio is 1:10 to 1:20; The processing temperature is 80-100℃; The processing time is 30-60 minutes.

[0025] The principle of color stripping is similar to reduction cleaning, but it requires higher dosages of chemicals and more drastic treatment conditions (higher temperatures and longer durations) to fully destroy the dye chromophores already fixed inside the fibers, thus removing or lightening the color. For polyester fabrics, because disperse dyes penetrate deeper into the fibers, color stripping requires high temperature and high pressure conditions (120-135℃); for cotton or nylon fabrics, normal pressure conditions (80-100℃) are sufficient to achieve good results. Color stripping can be used to treat dyeing defects (such as uneven coloring, stains, and color differences), enabling fabric repair and reuse, and reducing waste.

[0026] Compared with the prior art, the biomass-based liquid reducing cleaning agent and its application method provided by the present invention have the following beneficial effects: 1. Excellent environmental friendliness: High bio-based content: Hydrated reducing sugars are derived from plants, with a total biomass content of >90%. Biomass carbon is used to replace fossil carbon, and carbon emissions throughout the entire life cycle are reduced by more than 90% compared to sodium hydrosulfite.

[0027] Low COD: The COD of a 5g / L aqueous solution is less than 700 ppm, which is much lower than that of residual sodium hydrosulfite (usually >1500 ppm), and can reduce the wastewater treatment load by more than 50%.

[0028] High biodegradability: Both hydrated reducing sugars and tallow alkyl ethoxylates are biodegradable, with a biodegradability of >90% after 28 days and no persistent pollution.

[0029] Sulfur-free and phosphorus-free: This completely avoids the introduction of sulfur and phosphorus elements into wastewater, eliminating the risk of foul odors and eutrophication caused by sulfides.

[0030] 2. Significantly improves operational and storage safety: Liquid form: The product is a homogeneous and stable liquid with no dust, avoiding the risk of inhalation health hazards to workers.

[0031] Non-flammable and non-explosive: The product has a flash point >100℃, does not spontaneously combust, and poses no risk of explosion, completely solving the storage and transportation problems of sodium hydrosulfite, which is flammable and explosive when exposed to moisture.

[0032] Low odor: The product has no irritating odor, improving the workshop working environment.

[0033] 3. Excellent application performance and process stability: Highly efficient reduction cleaning effect: After reduction cleaning of polyester disperse dye-dyed fabrics, the wash fastness and rubbing fastness can fully reach or even exceed the level of traditional sodium hydrosulfite process.

[0034] Stable reducing power: The product is a thermodynamically stable solution system, and its reducing power will not decrease with prolonged storage time, ensuring consistent dyeing results between batches and reducing batch-to-batch variation.

[0035] Broad spectral applicability: Suitable for disperse dyes with various structures such as azo, anthraquinone, and heterocyclic.

[0036] Excellent color removal ability: It exhibits good color removal ability under high temperature and high pressure conditions (130℃) or normal pressure conditions (98℃ / 85℃), and can be effectively used for the repair of dyeing defects.

[0037] Simplified process, energy and water saving: When using this product for reduction cleaning, because the pH of the treatment bath is moderate, a separate neutralization step is usually not required, which can shorten the processing flow, save 20-30% of water, and reduce energy consumption. Attached Figure Description

[0038] Figure 1 This is a diagram illustrating the effect of using a bio-based liquid reducing cleaning agent and sodium hydrosulfite to perform reducing cleaning on black fabric in Embodiment 1 of the present invention. Figure 2 This is a diagram illustrating the effect of using a bio-based liquid reducing cleaning agent and sodium hydrosulfite to perform reducing cleaning on a red fabric in Embodiment 2 of the present invention. Figure 3 This is a diagram illustrating the effect of using a bio-based liquid reducing cleaning agent and sodium hydrosulfite in the stripping process of polyester fabrics in Example 4 of the present invention. Figure 4 This is a diagram illustrating the effect of using a bio-based liquid reducing cleaning agent and sodium hydrosulfite in the stripping process of gold-dyed cotton fabrics in Example 5 of the present invention. Figure 5 This is an illustration of the effect of applying bio-based liquid reducing cleaning solution and sodium hydrosulfite to various other colored fabrics in an embodiment of the present invention for the color stripping process; Figure 6 This is another effect diagram of the color stripping process applied to various other colored fabrics using bio-based liquid reducing cleaning solution and sodium hydrosulfite in an embodiment of the present invention. Figure 7 This is an illustration of the effect of applying a bio-based liquid reducing cleaning agent and sodium hydrosulfite to various other colored fabrics in a reducing cleaning process according to an embodiment of the present invention. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be described in detail below with reference to specific embodiments and comparative examples. However, it should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without inventive effort are within the scope of protection of this invention.

[0040] An embodiment of the present invention provides a bio-based liquid reducing cleaning agent, namely Reduction RCO Plus, which, by weight percentage, comprises 30-35% hydrated reducing sugar, 1-2% tallow alkyl ethoxylate, and the remainder being water; wherein, the hydrated reducing sugar is a reducing sugar substance derived from plant-based raw materials, including one or more of glucose, fructose, maltose, lactose, gluconic acid, sodium gluconate, and their hydrates; a 10% aqueous solution of the bio-based liquid reducing cleaning agent has a pH value of 7-9 at 20°C and can be used for the post-dyeing treatment of fabrics, such as reduction washing and stripping processes.

[0041] Furthermore, the biomass-based liquid reducing cleaning agent of this invention meets the following characteristics: a) total biomass content greater than 90%; b) 28-day biodegradability greater than 90%; c) chemical oxygen demand (COD) of 5 g / L aqueous solution less than 700 ppm; d) free of sulfides; e) flash point higher than 100℃, non-self-igniting. The total biomass content greater than 90% means that the vast majority of the carbon in the product comes from renewable plant resources, rather than fossil fuels, thus significantly reducing the carbon footprint. Calculations show that the carbon emissions of the cleaning agent of this invention throughout its entire life cycle can be reduced by more than 90% compared to traditional sodium hydrosulfite. High biodegradability (>90%) ensures that the product can be rapidly decomposed by microorganisms in the natural environment after use, without causing persistent pollution. Low COD (<700 ppm) means that the product itself places a smaller load on wastewater treatment systems and does not increase COD emissions during use. The absence of sulfides completely eliminates the risk of sulfur pollution, avoiding foul odors and ecotoxicity in water bodies. The high flash point and non-self-ignition properties ensure the safety of the product during storage and transportation, completely eliminating the safety hazards of sodium hydrosulfite being flammable and explosive.

[0042] To demonstrate the technical superiority of the reducing cleaning agent of the present invention, a performance comparison test was conducted between the reducing cleaning agent of the present invention and conventional sodium hydrosulfite. Specifically: Raw material preparation: The reducing cleaning agent (formulated using the formula of this invention) has the following specific components: 32.5% hydrated reducing sugar (calculated as sodium gluconate), 1.5% tallow alkyl ethoxylated amine (ethoxylated tallow alkylamine, CAS: 61791-26-2), and 66.0% deionized water. The pH of this cleaning agent should be adjusted to 7-9 during application.

[0043] Sodium dithionite (comparative example): Commercially available sodium dithionite (purity ≥85%).

[0044] Alkalinity regulator: 45% sodium hydroxide solution (industrial grade).

[0045] Disperse dyes: Commercially available, including disperse black, disperse red, disperse orange, disperse yellow-brown, etc.

[0046] Fabrics: double-knitted fabric, nylon fabric, brushed fabric, cotton fabric, acrylic fabric, wool fabric, polyester or acetate fabric, etc.

[0047] Test method: Wash fastness: Tested according to AATCC Test Method 61-2A standard, using multifiber fabric.

[0048] Friction fastness: Tested according to AATCC Test Method 8.

[0049] COD value: determined according to the dichromate method of HJ 828-2017 Determination of Chemical Oxygen Demand in Water.

[0050] Color stripping effect evaluation: Color difference is determined visually or measured and calculated using a colorimeter. A Datacolor800 colorimeter can be used to measure the L, a, and b values ​​of the fabric before and after treatment, and to calculate the color difference ΔE.

[0051] Example 1: The reducing cleaning effect of the present invention on black fabrics Preparation of dyed fabric: Using a dye combination of 4.8% disperse black, 0.09% disperse red, and 0.67% disperse orange, dye the fabric for 60 minutes at a liquor ratio of 1:10 and a temperature of 130°C to obtain the dyed fabric.

[0052] Restoration cleaning process: Formula: 3 g / L of reducing cleaning agent of this invention, 2 g / L of 45% sodium hydroxide solution (as an alkaline adjuster to adjust the pH of the treatment bath to 8.5), bath ratio: 1:10, temperature and time: 85℃×20 minutes, post-treatment: after draining, wash with hot water (60℃) for 10 minutes, wash with cold water for 10 minutes, and dry.

[0053] Test results: The results of the wash fastness and rubbing fastness of each fabric are shown in Table 1.

[0054] Comparative Example 1: Traditional Sodium Hydrosulfite Process The dyed fabric is the same as in Example 1.

[0055] Reduction cleaning process: 3 g / L sodium hydrosulfite, 2 g / L 45% sodium hydroxide solution, bath ratio 1:10, temperature and time 85℃×20min, post-treatment: draining, hot water washing (70℃) for 15 minutes, acetic acid neutralization (1 g / L, 50℃, 10min), warm water washing (40℃) for 10 minutes, cold water washing for 10 minutes, drying.

[0056] Test results: The results of the wash fastness and rubbing fastness of each fabric are shown in Table 1.

[0057] Example 2: The effect of the reducing cleaning agent of the present invention on the reducing cleaning of red fabrics Preparation of dyed fabric: Using a dye combination of 0.6% Disperse Orange, 2.0% Disperse Red, and 1.5% Disperse Red 2, dyeing was carried out at a liquor ratio of 1:10 and 130℃ for 60 minutes to obtain dyed fabric.

[0058] Restoration cleaning process: Formula: 3 g / L of the cleaning agent of this invention, 2 g / L of 45% sodium hydroxide solution (as an alkalinity adjuster to adjust the pH of the treatment bath to 8.5), bath ratio: 1:10, temperature and time: 85℃×20 minutes, post-treatment: after draining, wash with hot water (60℃) for 10 minutes, wash with cold water for 10 minutes, and dry.

[0059] Test results: The results of the wash fastness and rubbing fastness of each fabric are shown in Table 1.

[0060] Comparative Example 2: Traditional Sodium Hydrosulfite Process The dyed fabric is the same as in Example 2.

[0061] Reduction cleaning process: 3 g / L sodium hydrosulfite, 2 g / L 45% sodium hydroxide solution, bath ratio 1:10, temperature and time 85℃×20min, post-treatment: draining, hot water washing (70℃) for 15 minutes, acetic acid neutralization (1 g / L, 50℃, 10min), warm water washing (40℃) for 10 minutes, cold water washing for 10 minutes, drying.

[0062] Test results: The results of the wash fastness and rubbing fastness of each fabric are shown in Table 1.

[0063] Table 1: Comparison of fastness of fabrics from Example 1 and Comparative Example 1 / Example 2 and Comparative Example 2

[0064] Actual fabric test results are shown in the image. Figure 1 and Figure 2 As shown.

[0065] According to Table 1 and Figure 1 , Figure 2 The results show that using the cleaning agent of this invention in conjunction with an alkaline conditioner, its reduction cleaning effect on nylon, polyester, and wool fabrics is superior to the traditional sodium hydrosulfite process in terms of wash color fastness and wet rubbing fastness. In other aspects, it can replace sodium hydrosulfite. The color difference between the cleaning agent of this invention and sodium hydrosulfite after the reduction washing process is not significantly different, and they can also be used interchangeably. Furthermore, the post-treatment process of the reduction washing of this invention is shorter and does not require a separate neutralization step.

[0066] In particular, in Examples 1 and 2, when the raw material composition of the reducing cleaning agent was changed: the mass fraction of hydrated reducing sugar (calculated as sodium gluconate) was replaced with 30% or 35%, or the mass fraction of tallow alkyl ethoxylate was replaced with 1% or 2%, the test results on the fabric remained basically consistent.

[0067] Example 3: COD Comparison Test The COD values ​​of the reduction cleaning residue (after filtration to remove fiber fuzz) from Example 1 and Comparative Example 1 were measured.

[0068] Results: The residual COD of Example 1 was 680 ppm; the residual COD of Comparative Example 1 was 1580 ppm. The cleaning agent of this invention reduced the residual COD by 57%.

[0069] Example 4: The color-peeling effect of the cleaning agent of the present invention on polyester fabrics under high temperature and high pressure. Dyed fabric: polyester brushed fabric dyed with Disperse Black XF 4%.

[0070] Color peeling process: Example 4 Formulation: 10 g / L of the cleaning agent of the present invention, 5 g / L of 45% sodium hydroxide solution (adjusted to pH 8.0).

[0071] Comparative Example 4 formulation: 10 g / L sodium hydrosulfite, 5 g / L 45% sodium hydroxide solution.

[0072] Bath ratio: 1:10.

[0073] Processing conditions: a: 130℃×30min, b: 98℃×30min.

[0074] For example, the color peeling effect Figure 3 As shown.

[0075] Color difference: Visual inspection and colorimeter measurement: The color depth L value of the fabric after stripping at 130℃ in Example 4 is 42.5, and the L value of Comparative Example 4 is 41.8, ΔE=0.9, and the difference is not discernible to the naked eye.

[0076] Effect evaluation: Reference Figure 3 The results showed that the two methods had comparable color-peeling effects and could be used interchangeably.

[0077] Example 5: The effect of the cleaning agent of the present invention on the stripping effect of gold-containing dyes on cotton fabrics Dyed fabrics: Cotton knitted fabrics dyed with 4% gold dye.

[0078] Color peeling process: Example 5 formulation: 10 g / L of the cleaning agent of the present invention, 5 g / L of 45% sodium hydroxide solution (adjusted to pH 8.5).

[0079] Comparative Example 5 formulation: 10 g / L sodium hydrosulfite, 5 g / L 45% sodium hydroxide solution.

[0080] Bath ratio: 1:10.

[0081] Processing conditions: a: 130℃×30min, b: 98℃×30min.

[0082] For example, the color-peeling effect Figure 4 As shown.

[0083] The color-reducing cleaning agent of this invention has the following effect on the color-removing properties of other colored fabrics: Figure 5 and Figure 6 As shown.

[0084] It should be noted that when the 45% sodium hydroxide solution in Examples 4 and 5 and their comparative examples was replaced with 8 g / L, the stripping process did not change significantly. However, when the solution was replaced with 8.5 g / L, the fabric showed slight burns and slight hardening.

[0085] Effect evaluation: Reference Figures 4-6 The results showed that both methods had comparable color-removing effects and could be used interchangeably. In Example 5, the treated fabric had a better hand feel and no irritating odor from residual sodium hydrosulfite.

[0086] Example 6: Comparison of the reducing cleaning effect of different amounts of alkaline regulator To verify the effect of the amount of alkaline regulator, the amount of the cleaning agent of this invention was fixed at 3 g / L, and the amount of 45% sodium hydroxide solution was changed to 1 g / L, 2 g / L, 3 g / L, 4 g / L and 5 g / L, respectively, corresponding to the pH values ​​of the treatment baths of 6.5, 7.2, 8.0, 8.8 and 9.5, respectively. Other conditions were the same as in Example 1. The wet rubbing fastness of the fabric and the residual COD of the solution were tested after cleaning.

[0087] result: NaOH 1g / L (pH 6.5): wet rubbing fastness grade 3.0, residual COD 850 ppm.

[0088] NaOH 2g / L (pH 7.2): wet rubbing fastness grade 3.5, residual COD 720 ppm.

[0089] NaOH 3g / L (pH 8.0): wet rubbing fastness grade 4.0, residual COD 690 ppm.

[0090] NaOH 4g / L (pH 8.8): wet rubbing fastness grade 4.5, residual COD 680 ppm.

[0091] NaOH 5g / L (pH 9.5): wet rubbing fastness grade 4.5, residual COD 710 ppm (excess alkali caused partial hydrolysis, COD increased slightly).

[0092] The results showed that when the pH of the treatment bath was in the range of 7-9 (corresponding to a sodium hydroxide dosage of 2-4 g / L for 45%), the reduction cleaning effect was excellent and the COD was low. The preferred sodium hydroxide dosage was 2-4 g / L, more preferably 3-4 g / L.

[0093] Example 7: The adaptability of the cleaning agent of the present invention to different types of dyes Azo disperse red, anthraquinone disperse blue, and heterocyclic disperse yellow were used to dye polyester fabrics, respectively. Then, the fabrics were treated using the reduction cleaning process described in Example 1 (3 g / L of the cleaning agent of this invention, 2 g / L of 45% sodium hydroxide, 85℃×20 min). The K / S value and color difference of the fabrics before and after cleaning were tested.

[0094] like Figure 7 As shown, the results indicate that the floating color removal rate of fabrics dyed with various dyes all reached over 85%, and the wash fastness of the fabrics after washing all reached grade 4 or above. This shows that the cleaning agent of the present invention has good broad-spectrum adaptability to disperse dyes with different chemical structures and can replace sodium hydrosulfite.

[0095] Comparative Example 6: Cleaning agents without tallow alkyl ethoxylate A comparative cleaning agent was prepared, containing only 32.5% sodium gluconate and 67.5% water, and free of tallow alkyl ethoxylate. The same black polyester fabric was treated using the same reduction cleaning process as in Example 1 (3 g / L comparative cleaning agent, 2 g / L 45% sodium hydroxide, 85°C × 20 min).

[0096] The results showed that the wet rubbing fastness of the treated fabric was only grade 3.0, and the residual liquid was dark in color, indicating that the removal of floating dye was incomplete. This suggests that tallow alkyl ethoxylate is necessary as a synergistic dispersing component, as it can significantly improve the dispersion and removal efficiency of floating dye.

[0097] The above embodiments and comparative examples fully demonstrate the superiority of the technical solution of the present invention: The product's ingredients are clearly defined and effective: The cleaning agent of this invention consists of 30-35% hydrated reducing sugar, 1-2% tallow alkyl ethoxylate, and water, making its composition simple and clear. Example 6 demonstrates the importance of weakly alkaline conditions (pH 7-9), and Comparative Example 6 demonstrates the necessity of tallow alkyl ethoxylate.

[0098] Outstanding environmental friendliness: Example 2 shows that the cleaning agent of the present invention can reduce the residual COD by 57% (from 1580 ppm to 680 ppm). Combined with the product's high biomass content (>90%), high biodegradability (>90%), and sulfur-free characteristics, its environmental friendliness far exceeds that of sodium hydrosulfite.

[0099] Excellent application performance: Examples 1 and 3 show that the cleaning agent of the present invention has a fastness performance in reduction cleaning that reaches or exceeds that of sodium hydrosulfite; Examples 4 and 5 show that its effect in color removal is comparable to that of sodium hydrosulfite.

[0100] Wide process window and simple operation: Example 6 shows that the cleaning agent of the present invention can achieve good results in a wide range of alkaline regulator dosage (2-4 g / L NaOH), and no separate neutralization step is required in the post-treatment, making the operation simple.

[0101] Broad Spectrum Adaptability: Example 7 shows that the cleaning agent of the present invention is suitable for disperse dyes with various structural types such as azo, anthraquinone, and heterocyclic.

[0102] The bio-based liquid reducing cleaning agent and its application method provided by this invention can be used for the reduction cleaning treatment of various polyester and blended fabrics after dyeing, as well as for the stripping and repair of dyeing defects. Its raw materials are widely available, the preparation process is simple, the application is convenient, it is environmentally friendly, safe and reliable, and it has extremely high industrial practical value and promising prospects for widespread application.

[0103] The above embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention shall fall within the scope of protection claimed by the present invention.

Claims

1. A biomass-based liquid reducing cleaning agent, characterized in that, By weight percentage, it includes 30-35% hydrated reducing sugars, 1-2% tallow alkyl ethoxylates, and the remainder is water; The hydrated reducing sugar is a reducing sugar substance derived from plant-based raw materials, including one or more of glucose, fructose, maltose, lactose, gluconic acid, sodium gluconate and their hydrates; The pH value of a 10% aqueous solution of the biomass-based liquid reducing cleaning agent is 7-9 at 20°C.

2. The biomass-based liquid reducing cleaning agent according to claim 1, characterized in that, The bio-based liquid reducing cleaning agent meets one or more of the following characteristics: a) Total biomass content greater than 90%; b) Biodegradability greater than 90% after 28 days; c) The chemical oxygen demand of a 5 g / L aqueous solution is less than 700 ppm; d) Contains no sulfides; e) Flash point above 100℃, does not spontaneously combust.

3. A method for applying the bio-based liquid reducing cleaning agent as described in any one of claims 1-2, characterized in that, include: The bio-based liquid reducing cleaning agent and alkaline regulator are added to the treatment bath to perform reducing cleaning on polyester fabrics dyed with disperse dyes.

4. The application method according to claim 3, characterized in that, The process conditions for the reduction cleaning are as follows: The dosage of the biomass-based liquid reducing cleaning agent is 2.0-5.0 g / L; The dosage of the alkaline regulator is 2.0-4.0 g / L; The bath ratio is 1:10 to 1:20; The processing temperature is 80-85℃; The processing time is 15-25 minutes.

5. The application method according to claim 4, characterized in that, The alkalinity regulator is selected from one or more of sodium hydroxide, potassium hydroxide, and sodium carbonate.

6. A method for applying the biomass-based liquid reducing cleaning agent as described in any one of claims 1-2, characterized in that, include: In the stripping process of dyed defective fabrics, the bio-based liquid reducing cleaning agent and alkaline regulator are added to the treatment solution to strip the fabric. The alkaline regulator is selected from one or more of sodium hydroxide, potassium hydroxide, and sodium carbonate.

7. The application method according to claim 6, characterized in that, The stripping process is applied to polyester fabrics, and the process conditions are as follows: The dosage of the biomass-based liquid reducing cleaning agent is 5.0-10.0 g / L; The dosage of the alkaline regulator is 5.0-8.0 g / L; The bath ratio is 1:10 to 1:20; The processing temperature is 120-135℃; The processing time is 30-60 minutes.

8. The application method according to claim 6, characterized in that, The stripping process is applied to cotton or nylon fabrics, and the process conditions are as follows: The dosage of the biomass-based liquid reducing cleaning agent is 5.0-10.0 g / L; The dosage of the alkaline regulator is 5.0-8.0 g / L; The bath ratio is 1:10 to 1:20; The processing temperature is 80-100℃; The processing time is 30-60 minutes.

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