A high-viscosity, high-transparency cellulose ether, a method for preparing the same, and a detergent

Abstract

This application relates to the field of daily chemical detergents, specifically disclosing a high-viscosity, high-transmittance cellulose ether, its preparation method, and a detergent. A method for preparing the high-viscosity, high-transmittance cellulose ether includes the following steps: dispersing cellulose raw materials in isopropanol, stirring until homogeneous, adding deionized water, then reacting with a liquid molten salt hydrate, and finally adding sodium hydroxide, propylene oxide, and chloromethane to obtain the high-viscosity, high-transmittance cellulose ether. A detergent is provided, using raw materials including: bio-based AES, high-viscosity, high-transmittance cellulose ether, bio-based LABSA, additives, and water. The high-viscosity, high-transmittance cellulose ether of this application has a transmittance ≥88.9%, a Brookfield viscosity ≥81000 mPa·s at 20°C, and a detergent transmittance ≥96%, a Brookfield viscosity of 500-800 mPa·s at 20°C, a stain removal ratio ≥2.5 for sesame oil, and good detergency in hard water environments.

Description

Technical Field

[0001] This application relates to the technical field of daily chemical detergents, and in particular to a high-viscosity, high-transmittance cellulose ether, its preparation method, and a detergent. Background Technology

[0002] In the daily chemical detergent industry, surfactant technology and the application of additives are developing rapidly. As the core component for achieving detergency, the performance improvement of surfactants is crucial to the detergency of detergents. Cellulose ethers, as thickeners, stabilizers, and anti-redeposition additives, also play an indispensable role in detergent formulations. With the continuous improvement of people's requirements for the performance of detergent products, such as better detergency, a gentler user experience, and stability under different water quality environments, related technologies are constantly being improved, driving the daily chemical detergent industry forward and providing people with a better washing experience.

[0003] In traditional detergent formulations, a single surfactant or a blend of different surfactants is typically used to achieve detergency. A single surfactant is the most basic choice, directly utilizing its surface activity to reduce surface tension and thus achieve detergency. In surfactant blends, a common approach is to combine sodium linear alkylbenzene sulfonate (LABSA) with sodium fatty alcohol polyoxyethylene ether sulfate (AES), hoping to enhance detergency through their synergistic effect. Simultaneously, hydroxypropyl methylcellulose ether (HPMC) is often used as an additive to adjust the viscosity and stability of the detergent, utilizing its thickening and stabilizing properties to improve product performance. Furthermore, the properties of cellulose ethers are also utilized to prevent redeposition of dirt.

[0004] However, traditional detergent formulations have many drawbacks. The high critical micelle concentration of a single surfactant leads to low detergency, failing to meet the demand for highly effective cleaning. When AES and LABSA are combined, the ratio is difficult to balance; too much AES results in excessive foaming, while too much LABSA increases skin irritation, causing inconvenience and potential health risks to users. Furthermore, in hard water environments, surfactants tend to precipitate, significantly reducing detergency and failing to guarantee washing results under varying water quality conditions. Summary of the Invention

[0005] To address the aforementioned technical problems, this application provides a high-viscosity, high-transmittance cellulose ether, its preparation method, and a detergent.

[0006] In a first aspect, this application provides a method for preparing a high-viscosity, high-transmittance cellulose ether, comprising the following steps: Cellulose raw materials are dispersed in isopropanol at a weight ratio of (0.8-1.2):1, stirred evenly, and then deionized water is added. The weight ratio of deionized water to isopropanol is (1.5-2.5):1. The mixture is stirred for 20-25 hours at a speed of 10000-15000 rpm and a temperature of 25-40℃. Subsequently, it is mixed and reacted with liquid molten salt hydrate. Sodium hydroxide, propylene oxide and chloromethane are then added. After the reaction is carried out under vacuum, the mixture is washed to remove impurities, dehydrated, and washed until neutral. When the water content in the material is less than 60%, it is dried with hot air at 130℃ until the water content is less than 5%. Finally, it is pulverized and passed through a 20-mesh sieve to obtain high-viscosity, high-transmittance cellulose ether.

[0007] Preferably, the solid substance is dispersed in isopropanol at a weight ratio of 1:1.

[0008] Preferably, the weight ratio of deionized water to isopropanol is 2:1.

[0009] Preferably, the rotational speed is 13500 rpm.

[0010] Optionally, the liquid molten salt hydrate includes liquid lithium chloride molten salt hydrate and liquid magnesium chloride molten salt hydrate.

[0011] Optionally, the weight ratio of the cellulose raw material, sodium hydroxide, propylene oxide and chloromethane is 1:0.1:5:10.

[0012] By adopting the above technical solution, this application first disperses cellulose raw material in isopropanol, stirs it evenly, and then adds deionized water. The weight ratio of deionized water to isopropanol is (1.5-2.5):1. Stirring is carried out at a speed of 10000-15000 rpm and a temperature of 25-40℃ for 20-25 hours to ensure uniform molecular dispersion, thereby simultaneously improving the viscosity and transmittance of the product. Subsequently, it is blended with liquid molten salt hydrate. The Cl⁻ ions in the molten salt hydrate form strong hydrogen bonds with the cellulose hydroxyl groups, which destroys the intermolecular hydrogen bond network. At the same time, the Li⁺ solvation in the liquid lithium chloride molten salt hydrate reduces the ion pair binding energy and promotes the dissociation of cellulose chains. The liquid magnesium chloride molten salt hydrate acts as a co-solvent, which enhances the swelling capacity of cellulose by improving the ionic strength of the system and the synergistic solvation effect. Subsequently, sodium hydroxide is added to this application, causing the cellulose hydroxyl groups to deprotonate and generate sodium cellulose, forming nucleophilic active sites. Under vacuum conditions, propylene oxide and chloromethane act as electrophilic etherifying agents, undergoing a competitive nucleophilic substitution reaction. Propylene oxide undergoes ring opening, and its C2 carbon is attacked by cellulose oxygen anions to generate hydroxypropyl ether bonds. Chloromethane directly undergoes a Sn2 reaction to generate methyl ether bonds. This application controls the weight ratio of cellulose raw material, sodium hydroxide, propylene oxide, and chloromethane to 1:0.1:5:10, which can achieve the effect of high hydroxypropyl substitution and low methyl substitution. The vacuum environment significantly lowers the boiling point of propylene oxide, promoting its participation in the reaction in a gaseous state, inhibiting the self-polymerization side reaction of propylene oxide, and improving the substitution uniformity and reaction efficiency. The final product is a high-viscosity, high-transmittance cellulose ether ≥88.9%, with extremely low impurity content. At the same time, the Brookfield viscosity at 20°C is ≥81000 mPa·s, with a concentrated molecular weight distribution, high degree of substitution, and strong intermolecular forces, which can provide good thickening and stability.

[0013] Preferably, after adding deionized water, the temperature is increased in a gradient manner, specifically: first, stirring is carried out at a temperature of 25-30℃ for 10 hours, and then the temperature is increased to 35-40℃ to complete the stirring.

[0014] By adopting the above technical solution, the cellulose raw material of this application is dispersed in isopropanol and water, and then stirred under the condition of increasing the temperature in a gradient manner. This makes the dispersion of hydroxypropyl methylcellulose ether molecules more complete and uniform when hydroxypropyl methylcellulose ether is subsequently generated, resulting in hydroxypropyl methylcellulose ether products with higher viscosity and light transmittance.

[0015] Secondly, this application also provides a high-viscosity, high-transmittance cellulose ether prepared by the above-mentioned high-viscosity, high-transmittance cellulose ether preparation method, wherein the high-viscosity, high-transmittance cellulose ether has a transmittance ≥88.9% and a Brookfield viscosity ≥81000 mPa·s at 20°C.

[0016] By adopting the above technical solution, the high viscosity and high light transmittance cellulose ether obtained in this application has a viscosity of ≥88.9%, the impurity content in the product is extremely low, and the Brookfield viscosity at 20°C is ≥81000 mPa·s. The molecular weight distribution is concentrated, the degree of substitution is high, and the intermolecular forces are strong, which can provide good thickening and stability.

[0017] Thirdly, this application also provides a detergent, the raw materials of which, by weight percentage, include: Bio-based AES 1.2-1.4%; The high-viscosity, high-transmittance cellulose ether is 0.18-0.22%; Bio-based LABSA 2.5-3.0%; Sodium hydroxide 0.3-0.5%; Sodium chloride 1.2-1.4%; Silicone defoamer 0.05-0.1%; The remainder is water.

[0018] Preferably, the weight ratio of the bio-based AES to the bio-based LABSA is 1:2.15.

[0019] Preferably, the raw materials used, by weight percentage, include: Bio-based AES 1.3%; The high-viscosity, high-transmittance cellulose ether is 0.2%; Bio-based LABSA 2.8%; Sodium hydroxide 0.4%; Sodium chloride 1.3%; 0.08% silicone defoamer; The remainder is water.

[0020] By adopting the above technical solution, this application uses bio-based AES, high-viscosity and high-transmittance cellulose ether and bio-based LABSA as the main components of the detergent, and adds auxiliary components such as sodium hydroxide, sodium chloride and organosilicon defoamer to obtain a detergent with good detergency. The test results show that its transmittance is ≥96% and its Brookfield viscosity at 20℃ is 500-800mPa·s. Specifically, the hydrophilic polyoxyethylene ether chain of bio-based AES and the hydrophobic benzene ring group of bio-based LABSA form a "mixed micelle". Through steric hindrance, the aggregation degree between bio-based LABSA molecules is reduced, making the critical micelle concentration of the mixed system lower than that of the single component, thereby improving surface activity, reducing surface tension, and achieving a strong detergency effect. At the same time, the polyoxyethylene ether chain of bio-based AES can complex calcium and magnesium ions in hard water, reducing the insoluble calcium salt precipitation formed by LAS and hard water ions. Combined with the dispersing effect of cellulose ether, the system maintains stable detergency in hard water of 150-300 mg / L (calculated as CaCO3). This application effectively balances detergency, foam stability, and mildness by adjusting the mass ratio of bio-based AES and bio-based LABSA. More importantly, this application incorporates a high-viscosity, high-transmittance cellulose ether prepared by the aforementioned method, and uses NaCl electrolyte for synergistic thickening to achieve precise control of the target viscosity. The key lies in utilizing the hydrogen bonding of the cellulose ether molecular chain and the "salting-out effect" of the electrolyte to avoid viscosity fluctuations caused by a single thickener. The hydroxyl (-OH) and carboxyl groups (a small amount of oxidation products) in the cellulose ether molecule can be specifically adsorbed on the surface of fibers (cotton, synthetic fibers) and dirt (oil, dust) to form a protective film with a thickness of 5-10 nm. Through the steric hindrance effect, the redeposition of dirt is prevented, thus significantly improving the cleaning power.

[0021] By adopting the above technical solution In summary, this application has the following beneficial technical effects: 1. The preparation method of this application first disperses cellulose raw material in isopropanol, stirs it evenly, and then adds deionized water to ensure uniform molecular dispersion and simultaneously improve the viscosity and transmittance of the product. Then it is blended with liquid molten salt hydrate to enhance the swelling capacity of cellulose by improving the ionic strength of the system and the synergistic solvation effect. Then sodium hydroxide, propylene oxide and chloromethane are added to obtain high viscosity and high transmittance cellulose ether. The overall operation is simple and smooth and suitable for mass production. 2. The high viscosity and high light transmittance cellulose ether obtained in this application has a viscosity of ≥88.9%, the impurity content in the product is extremely low, and the Brookfield viscosity at 20°C is ≥81000 mPa·s. The molecular weight distribution is concentrated, the degree of substitution is high, and the intermolecular forces are strong, which can provide good thickening and stability. 3. This application utilizes bio-based AES, high-viscosity and high-transmittance cellulose ether and bio-based LABSA as the main components of the detergent, and adds auxiliary components such as sodium hydroxide, sodium chloride and organosilicon defoamer to obtain a detergent with good detergency, a transmittance of ≥96%, a Brookfield viscosity of 500-800 mPa·s at 20℃, and a stain removal ratio of more than 2.5 for sesame oil. Detailed Implementation

[0022] A method for preparing a high-viscosity, high-transmittance cellulose ether includes the following steps: Cellulose raw materials are dispersed in isopropanol at a weight ratio of (0.8-1.2):1, stirred evenly, and then deionized water is added. The weight ratio of deionized water to isopropanol is (1.5-2.5):1. The mixture is stirred for 20-25 hours at a speed of 10000-15000 rpm and a temperature of 25-40℃. Subsequently, it is mixed and reacted with liquid molten salt hydrate. Sodium hydroxide, propylene oxide and chloromethane are then added. After the reaction is carried out under vacuum, the mixture is washed to remove impurities, dehydrated, and washed until neutral. When the water content in the material is less than 60%, it is dried with hot air at 130℃ until the water content is less than 5%. Finally, it is pulverized and passed through a 20-mesh sieve to obtain high-viscosity, high-transmittance cellulose ether.

[0023] In a preferred embodiment of this application, the solid substance is dispersed in isopropanol at a weight ratio of 1:1.

[0024] In a preferred embodiment of this application, the weight ratio of deionized water to isopropanol is 2:1.

[0025] In a preferred embodiment of this application, the rotational speed is 13,500 rpm.

[0026] In a preferred embodiment of this application, the liquid molten salt hydrate includes liquid lithium chloride molten salt hydrate and liquid magnesium chloride molten salt hydrate.

[0027] In a preferred embodiment of this application, the weight ratio of the cellulose raw material, sodium hydroxide, propylene oxide and chloromethane is 1:0.1:5:10.

[0028] In a preferred embodiment of this application, after adding deionized water, the temperature is increased in a gradient manner, specifically: first, stirring is carried out at a temperature of 25-30°C for 10 hours, and then the temperature is increased to 35-40°C to complete the stirring.

[0029] A detergent, by weight percentage, contains the following raw materials: Bio-based AES 1.2-1.4%; High-viscosity, high-transmittance cellulose ethers: 0.18-0.22%; Bio-based LABSA 2.5-3.0%; Sodium hydroxide 0.3-0.5%; Sodium chloride 1.2-1.4%; Silicone defoamer 0.05-0.1%; The remainder is water.

[0030] In a preferred embodiment of this application, the weight ratio of the bio-based AES to the bio-based LABSA is 1:2.15.

[0031] In a preferred embodiment of this application, the raw materials used, by weight percentage, include: Bio-based AES 1.3%; High-viscosity, high-transmittance cellulose ether, 0.2%; Bio-based LABSA 2.8%; Sodium hydroxide 0.4%; Sodium chloride 1.3%; 0.08% silicone defoamer; The remainder is water.

[0032] The present application will be further described in detail below with reference to embodiments and comparative examples.

[0033] <Example 1> A method for preparing a high-viscosity, high-transmittance cellulose ether includes the following steps: Liquid lithium chloride molten salt hydrate and liquid magnesium chloride molten salt hydrate were dispersed together in water at a molar ratio of 10:1 to obtain a liquid molten salt hydrate with a total concentration of 70 wt% for later use. Disperse 80g of dissolving slurry in 100g of isopropanol, stir for 30min, then add 0.15L of deionized water, and stir for 25h at 15000rpm and 25℃. Mix 8kg of pre-prepared liquid molten salt hydrate with the above solution and stir at 25℃ for 20min. Then add 8g of sodium hydroxide, 400g of propylene oxide and 800g of chloromethane, and react for 5h under vacuum at 60℃. Wash to remove impurities, dehydrate, and wash until neutral. When the water content in the material is less than 60%, dry it with hot air at 130℃ until the water content is less than 5%. Finally, pulverize and pass through a 20-mesh sieve to obtain high-viscosity, high-transmittance cellulose ether.

[0034] <Example 2> A method for preparing a high-viscosity, high-transmittance cellulose ether includes the following steps: Liquid lithium chloride molten salt hydrate and liquid magnesium chloride molten salt hydrate were dispersed together in water at a molar ratio of 10:1 to obtain a liquid molten salt hydrate with a total concentration of 70 wt% for later use. 120g of dissolving slurry was dispersed in 100g of isopropanol and stirred for 30min. Then, 0.25L of deionized water was added, and the mixture was stirred for 20h at 10000rpm and 40℃. 12kg of pre-prepared liquid molten salt hydrate was mixed with the above solution and stirred for 20min at 25℃. Then, 12g of sodium hydroxide, 600g of propylene oxide and 1.2kg of chloromethane were added, and the mixture was reacted for 5h under vacuum at 60℃. After washing to remove impurities, dehydration and washing until neutral were achieved, and when the water content in the material was less than 60%, it was dried with hot air at 130℃ until the water content was less than 5%. Finally, it was pulverized and passed through a 20-mesh sieve to obtain high-viscosity, high-transmittance cellulose ether.

[0035] <Example 3.1> A method for preparing a high-viscosity, high-transmittance cellulose ether differs from Example 1 in that the amount of isopropanol used is 80g, while the rest is the same as in Example 1.

[0036] <Example 3.2> A method for preparing a high-viscosity, high-transmittance cellulose ether differs from Example 1 in that the amount of isopropanol used is 66.7g, while the rest is the same as in Example 1.

[0037] <Example 4.1> A method for preparing a high-viscosity, high-transmittance cellulose ether differs from Example 3.1 in that, after dispersing the dissolving slurry in isopropanol, the amount of deionized water added is 0.12 L, while the rest is the same as in Example 3.1.

[0038] <Example 4.2> A method for preparing a high-viscosity, high-transmittance cellulose ether differs from Example 3.1 in that, after dispersing the dissolving slurry in isopropanol, the amount of deionized water added is 0.16 L, while the rest is the same as in Example 3.1.

[0039] <Example 4.3> A method for preparing a high-viscosity, high-transmittance cellulose ether differs from Example 3.1 in that, after dispersing the dissolving slurry in isopropanol, the amount of deionized water added is 0.20 L, while the rest is the same as in Example 3.1.

[0040] <Example 5.1> A method for preparing a high-viscosity, high-transmittance cellulose ether differs from Example 1 in that the rotation speed is 12000 rpm, while the rest is the same as in Example 1.

[0041] <Example 5.2> A method for preparing a high-viscosity, high-transmittance cellulose ether differs from Example 1 in that the rotation speed is 13,500 rpm, while the rest is the same as in Example 1.

[0042] <Comparative Example 1> Includes the following steps: Liquid lithium chloride molten salt hydrate and liquid magnesium chloride molten salt hydrate were dispersed together in water at a molar ratio of 10:1 to obtain a liquid molten salt hydrate with a total concentration of 70 wt% for later use. 80g of dissolving slurry was mixed with 8kg of pre-prepared liquid molten salt hydrate and stirred at 25℃ for 20min. Then, 8g of sodium hydroxide, 400g of propylene oxide and 800g of chloromethane were added and reacted at 60℃ under vacuum for 5h. After washing to remove impurities, dehydration and washing until neutral were carried out. When the water content in the material was less than 60%, it was dried with hot air at 130℃ until the water content was less than 5%. Finally, it was pulverized and passed through a 20-mesh sieve to obtain high viscosity and high light transmittance cellulose ether.

[0043] <Comparative Example 2> Includes the following steps: Liquid lithium chloride molten salt hydrate and liquid magnesium chloride molten salt hydrate were dispersed together in water at a molar ratio of 10:1 to obtain a liquid molten salt hydrate with a total concentration of 70 wt% for later use. 80g of dissolving slurry was dispersed in 250g of isopropanol and stirred for 25h at 15000rpm and 25℃. 8kg of pre-prepared liquid molten salt hydrate was mixed with the above solution and stirred for 20min at 25℃. Then, 8g of sodium hydroxide, 400g of propylene oxide and 800g of chloromethane were added and reacted under vacuum at 60℃ for 5h. After washing to remove impurities, dehydration and washing until neutral were achieved. When the water content in the material was less than 60%, it was dried with hot air at 130℃ until the water content was less than 5%. Finally, it was pulverized and passed through a 20-mesh sieve to obtain high-viscosity, high-transmittance cellulose ether.

[0044] <Comparative Example 3> Includes the following steps: Liquid lithium chloride molten salt hydrate and liquid magnesium chloride molten salt hydrate were dispersed together in water at a molar ratio of 10:1 to obtain a liquid molten salt hydrate with a total concentration of 70 wt% for later use. 80g of dissolving slurry was dispersed in 0.25L of deionized water and then stirred for 25h at 15000rpm and 25℃. 8kg of pre-prepared liquid molten salt hydrate was mixed with the above solution and stirred for 20min at 25℃. Then, 8g of sodium hydroxide, 400g of propylene oxide and 800g of chloromethane were added and reacted under vacuum at 60℃ for 5h. After washing to remove impurities, dehydration and washing until neutral were achieved, and when the water content in the material was less than 60%, it was dried with hot air at 130℃ until the water content was less than 5%. Finally, it was pulverized and passed through a 20-mesh sieve to obtain high-viscosity, high-transmittance cellulose ether.

[0045] <Comparative Example 4> The difference from Example 1 is that the rotational speed is 8000 rpm, but everything else is the same as in Example 1.

[0046] <Application Example 1> A detergent is obtained by uniformly mixing the following substances: 12g of bio-based AES, 2.2g of high-viscosity, high-transmittance cellulose ether obtained in Example 1, 25g of bio-based LABSA, 5g of sodium hydroxide, 12g of sodium chloride, 1g of silicone defoamer, and 942.8mL of water.

[0047] <Application Example 2> A detergent is obtained by uniformly mixing the following substances: 14g of bio-based AES, 1.8g of high-viscosity, high-transmittance cellulose ether obtained in Example 2, 30g of bio-based LABSA, 3g of sodium hydroxide, 14g of sodium chloride, 0.5g of silicone defoamer, and 936.7mL of water.

[0048] <Application Example 3> A detergent is obtained by uniformly mixing the following substances: 13g of bio-based AES, 2.0g of high-viscosity, high-transmittance cellulose ether obtained in Example 1, 28g of bio-based LABSA, 4g of sodium hydroxide, 13g of sodium chloride, 0.8g of silicone defoamer, and 939.2mL of water.

[0049] <Application Example 4> A detergent is obtained by uniformly mixing the following substances: 12.5g bio-based AES, 2.0g high-viscosity, high-transmittance cellulose ether obtained in Example 1, 28.5g bio-based LABSA, 4g sodium hydroxide, 13g sodium chloride, 0.8g silicone defoamer, and 939.2mL water.

[0050] <Application Example 5> A detergent is obtained by uniformly mixing the following substances: 13.5g bio-based AES, 2.0g high-viscosity, high-transmittance cellulose ether obtained in Example 1, 27.5g bio-based LABSA, 4g sodium hydroxide, 13g sodium chloride, 0.8g silicone defoamer, and 939.2mL water.

[0051] <Application Example 6.1-6.2> A detergent, which differs from Application Example 3 in that the high viscosity and high transmittance cellulose ether prepared in Example 1 is replaced with the high viscosity and high transmittance cellulose ether prepared in Examples 3.1-3.2, while the rest is the same as Application Example 3.

[0052] <Application Example 7.1-7.3> A detergent, which differs from Application Example 6.1 in that the high viscosity, high transmittance cellulose ether prepared in Example 3.1 is replaced with the high viscosity, high transmittance cellulose ether prepared in Examples 4.1-4.3, while all other aspects are the same as in Application Example 6.1.

[0053] <Application Example 8.1-8.2> A detergent, which differs from Application Example 3 in that the high viscosity and high transmittance cellulose ether prepared in Example 1 is replaced with the high viscosity and high transmittance cellulose ether prepared in Examples 5.1-5.2, while the rest is the same as Application Example 3.

[0054] <Comparative Application Example 1> Detergent is obtained by uniformly mixing the following substances: 5.4g bio-based AES, 2.2g high-viscosity, high-transmittance cellulose ether obtained in Example 1, 21.6g bio-based LABSA, 5g sodium hydroxide, 12g sodium chloride, 1g silicone defoamer, and 942.8mL water.

[0055] <Comparative Application Example 2> Detergent is obtained by uniformly mixing the following substances: 13.5g bio-based AES, 2.2g high-viscosity, high-transmittance cellulose ether obtained in Example 1, 13.5g bio-based LABSA, 5g sodium hydroxide, 12g sodium chloride, 1g silicone defoamer, and 942.8mL water.

[0056] <Comparative Application Example 3.1-3.4> The detergent differs from Application Example 4 in that the high-viscosity, high-transmittance cellulose ether prepared in Example 1 is replaced with the high-viscosity, high-transmittance cellulose ether prepared in Comparative Examples 1-4, while the rest is the same as Application Example 4.

[0057] <Comparative Application Example 4> Detergent is obtained by uniformly mixing the following substances: 12g bio-based AES, 1.5g high-viscosity, high-transmittance cellulose ether obtained in Example 1, 25g bio-based LABSA, 5g sodium hydroxide, 12g sodium chloride, 1g silicone defoamer, and 943.5mL water.

[0058] <Comparative Application Example 5> Detergent is obtained by uniformly mixing the following substances: 12g of bio-based AES, 3.0g of high-viscosity, high-transmittance cellulose ether obtained in Example 1, 25g of bio-based LABSA, 5g of sodium hydroxide, 12g of sodium chloride, 1g of silicone defoamer, and 942mL of water.

[0059] Performance testing

[0060] 1. The high viscosity and high transmittance cellulose ethers obtained in the examples and comparative examples were subjected to Brookfield viscosity testing (20°C) and transmittance testing, and the results are recorded in Table 1.

[0061] 2. The transmittance and Brookfield viscosity (20°C) of the detergents obtained from the application examples and comparative application examples were measured, and the results are recorded in Table 1.

[0062] 3. In accordance with GB / T 13174-2021 "Determination of detergency and recycle performance of detergents for clothing", the detergency of the detergents obtained from the application examples and comparative application examples was tested, and the results are recorded in Table 1. The specific steps are as follows: Cut standard white cotton fabric into 6cm*6cm square pieces and put them in a washing machine using a standard program. The total washing time is 51 minutes, including one 13-minute main wash, two rinses, and one 5-minute spin dry. After washing, remove the fabric pieces and place them in a suitable container. Wash them with 60℃ deionized water for 30 minutes. After washing again, remove the fabric pieces, spin dry, and iron them flat. Set aside. Soak the prepared fabric pieces thoroughly in sesame oil solution. If the fabric pieces are not soaked sufficiently, apply some pressure to the top of the fabric pieces. After 20 minutes, remove them and air dry at room temperature. Set aside. If the fabric pieces are wrinkled, iron them flat. Four prepared blank fabric pieces were taken from each group. The whiteness value of each blank fabric piece was measured along both diagonals according to the method in standard GB / T 13174-2021. Sixteen data points were obtained from each group, recorded as F0. The fabric pieces with the initial whiteness values ​​were then used to prepare experimental soiled sheets, and their whiteness value was measured again, recorded as F1. Washing tests were conducted in groups within a vertical stain remover. UV lamps were used throughout the washing test. During the test, 1L of a 0.2% test solution was prepared using 400mg / kg hard water, containing the detergent from both the application example and the control application example. The solution was poured into the corresponding staining bath. The bath was placed in its designated position, and the stirring impeller was installed. The instrument was adjusted to maintain the washing test temperature at 30℃. The soiled sheets from section 1.2.2 were then placed into the bath. Stirring was started and maintained at a speed of 120r / min. The washing process... Stop after 20 minutes. Remove the test piece from the cleaning bath and place it in the inner tub of the rinser. Spin-dry for 15 seconds (inner tub speed approximately 1800 rpm). Drain the water, then pour 1.5L of tap water into the rinser and replace the lid. Rinse the test piece for 30 seconds at a uniform speed, alternating between 5 clockwise and 5 counterclockwise rotations. During this time, the inner tub should rotate fully, but avoid excessive rotation that could cause the rinse water to overflow. Drain the rinse water and manually spin-dry the test piece for 15 seconds. Add 1.5L of tap water again and repeat the second rinse and spin-drying process. Repeat this process four times in total. After the final rinse and spin-drying, remove the test piece and place it on an enamel plate to air dry at room temperature. Measure the whiteness F2. Calculate the stain removal ratio R = (F2 - F1) / F0 - F1. Table 1 Test Data

[0063] Data Analysis: As can be seen from Table 1, the preparation method of this application, after dispersing the cellulose raw material in isopropanol and water, increases the temperature in a gradient manner, which promotes a more complete and uniform dispersion of hydroxypropyl methylcellulose ether molecules during the subsequent formation of hydroxypropyl methylcellulose ether. This results in a hydroxypropyl methylcellulose ether product with higher viscosity and light transmittance. Therefore, the final high-viscosity, high-light-transmittance cellulose ether obtained has a viscosity ≥88.9%, extremely low impurity content, and a Brookfield viscosity ≥81000 mPa·s at 20℃. It also exhibits a concentrated molecular weight distribution, high degree of substitution, and strong intermolecular forces, providing good thickening and stability.

[0064] This application utilizes bio-based AES, high-viscosity and high-transmittance cellulose ether and bio-based LABSA as the main components of the detergent, and adds auxiliary components such as sodium hydroxide, sodium chloride and organosilicon defoamer to obtain a detergent with good detergency. The test results show that its transmittance is ≥96% and its Brookfield viscosity at 20℃ is 500-800 mPa·s. Specifically, the hydrophilic polyoxyethylene ether chain of bio-based AES and the hydrophobic benzene ring group of bio-based LABSA form a "mixed micelle". Through steric hindrance, the aggregation degree between bio-based LABSA molecules is reduced, making the critical micelle concentration of the mixed system lower than that of the single component, thereby improving surface activity, reducing surface tension, and achieving a strong detergency effect. At the same time, the polyoxyethylene ether chain of bio-based AES can complex calcium and magnesium ions in hard water, reducing the insoluble calcium salt precipitation formed by LAS and hard water ions. Combined with the dispersing effect of cellulose ether, the system maintains stable detergency in hard water of 150-300 mg / L (calculated as CaCO3). This application effectively balances detergency, foam stability, and mildness by adjusting the mass ratio of bio-based AES and bio-based LABSA. More importantly, this application incorporates a high-viscosity, high-transmittance cellulose ether prepared by the aforementioned method, and uses NaCl electrolyte for synergistic thickening to achieve precise control of the target viscosity. The key lies in utilizing the hydrogen bonding of the cellulose ether molecular chain and the "salting-out effect" of the electrolyte to avoid viscosity fluctuations caused by a single thickener. The hydroxyl (-OH) and carboxyl groups (a small amount of oxidation products) in the cellulose ether molecule can be specifically adsorbed on the surface of fibers (cotton, synthetic fibers) and dirt (oil, dust) to form a protective film with a thickness of 5-10 nm. Through the steric hindrance effect, the redeposition of dirt is prevented, thus significantly improving the cleaning power.

[0065] The embodiments described in this specific implementation are preferred embodiments of this application and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A method for preparing a high-viscosity, high-transmittance cellulose ether, characterized in that, Includes the following steps: Cellulose raw materials were dispersed in isopropanol at a weight ratio of (0.8-1.2):1, stirred evenly, and then deionized water was added. The weight ratio of deionized water to isopropanol was (1.5-2.5):

1. The mixture was stirred for 20-25 hours at a speed of 10000-15000 rpm and a temperature of 25-40℃. Subsequently, it was mixed and reacted with liquid molten salt hydrate. Sodium hydroxide, propylene oxide and chloromethane were then added. After reacting under vacuum, the mixture was washed to remove impurities, dehydrated, washed until neutral, dried, pulverized and sieved to obtain high viscosity and high light transmittance cellulose ether.

2. The method for preparing a high-viscosity, high-transmittance cellulose ether according to claim 1, characterized in that, The solid substance is dispersed in isopropanol at a weight ratio of 1:

1.

3. The method for preparing a high-viscosity, high-transmittance cellulose ether according to claim 1, characterized in that, The weight ratio of deionized water to isopropanol is 2:

1.

4. The method for preparing a high-viscosity, high-transmittance cellulose ether according to claim 1, characterized in that, The rotational speed is 13,500 rpm.

5. The method for preparing a high-viscosity, high-transmittance cellulose ether according to claim 1, characterized in that, After adding deionized water, the temperature is increased in a gradient manner, specifically: first, stir at 25-30℃ for 10 hours, then raise the temperature to 35-40℃ to complete the stirring.

6. A high-viscosity, high-transmittance cellulose ether prepared by the method according to any one of claims 1-5, characterized in that, The high-viscosity, high-transmittance cellulose ether has a transmittance of ≥88.9% and a Brookfield viscosity of ≥81000 mPa·s at 20°C.

7. A detergent, characterized in that, The raw materials used, by weight percentage, include: Bio-based AES 1.2-1.4%; The high-viscosity, high-transmittance cellulose ether is 0.18-0.22%; Bio-based LABSA 2.5-3.0%; Sodium hydroxide 0.3-0.5%; Sodium chloride 1.2-1.4%; Silicone defoamer 0.05-0.1%; The remainder is water.

8. A detergent according to claim 7, characterized in that, The weight ratio of the bio-based AES to the bio-based LABSA is 1:2.

15.

9. A detergent according to claim 8, characterized in that, The raw materials used, by weight percentage, include: Bio-based AES 1.3%; The high-viscosity, high-transmittance cellulose ether is 0.2%; Bio-based LABSA 2.8%; Sodium hydroxide 0.4%; Sodium chloride 1.3%; 0.08% silicone defoamer; The remainder is water.

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