Biological compound enzyme mediated low-temperature stain-removing microcapsule slow-release fragrance-retaining laundry detergent

Abstract

The invention belongs to the technical field of detergents, and particularly relates to a biological compound enzyme mediated low-temperature stain-removing microcapsule slow-release fragrance-retaining laundry detergent. The shampoo is prepared from the following components: sodium laureth sulfate, fatty alcohol-polyoxyethylene ether, cocamidopropyl betaine, sodium citrate, sodium tetrasodium glutamate diacetate, anhydrous sodium carbonate, glycerol, sodium carboxymethyl cellulose, hydroxyethyl cellulose, benzisothiazolinone, compound enzyme microcapsule slurry, sachet microcapsule slurry and the balance of deionized water. According to the preparation method, time-sharing triggering and structure separation are taken as the core, and the compound enzyme is embedded in the alginate microgel, so that isolation protection in the storage period and quick release in the front section of washing are realized, and the low-temperature stain removal stability is improved; the essential oil is encapsulated by using the polyurea shell microcapsules, so that the fragrance is slowly released in a peak shifting manner, and enzyme inhibition is avoided; meanwhile, a low-temperature stain removal, enzyme stability and lasting fragrance retention compatible system is constructed.

Description

Technical Field

[0001] This invention belongs to the field of detergent technology, specifically relating to a bio-complex enzyme-mediated low-temperature stain removal microcapsule slow-release fragrance laundry detergent. Background Technology

[0002] With the improvement of residents' living standards, increased awareness of environmental protection and energy conservation, and the diversification of clothing materials, laundry detergent has gradually replaced traditional laundry powder and is widely used in the daily chemical washing field. Compared with laundry powder, laundry detergent has the characteristics of fast dissolution and less damage to clothes. It can be used with a variety of materials such as cotton, linen, silk, and wool, and is suitable for a variety of washing scenarios.

[0003] Currently, the cleaning function of laundry detergent mainly relies on the synergistic effect of surfactant systems and functional additives. Surfactants are responsible for reducing the surface tension of water and emulsifying and breaking down grease stains, while enzymes such as proteases and lipases specifically break down stubborn protein and starch stains. Chelating agents, buffers, and other additives are used to improve the stability of the washing system and enhance cleaning performance. In recent years, energy-saving low-temperature washing has become an industry trend. This washing method can save water and energy consumption and avoid damage to clothing materials from high temperatures, but it also places higher technical demands on the low-temperature stain removal performance of laundry detergents.

[0004] Current laundry detergents still suffer from several technical challenges in practical applications, struggling to balance cleaning performance, enzyme activity stability, and environmental compatibility. Firstly, low-temperature stain removal efficiency is insufficient. At low temperatures, the solubility and diffusion rate of nonionic surfactants decrease, significantly inhibiting enzyme activity. The decomposition rate is far lower than under warm water conditions, making it difficult to thoroughly remove stubborn stains such as grease and sweat. Some products compensate for this deficiency by increasing the amount of surfactant, which not only increases system costs but may also increase system irritation. Secondly, enzyme stability is poor. In conventional laundry detergent systems, enzymes coexist directly with surfactants and preservatives, making them susceptible to inactivation due to chemical environments. Simultaneously, high temperatures cause enzyme denaturation and inactivation, while low temperatures limit their activity. These factors severely affect the stability of washing performance, and some incompletely inactivated enzymes may even cause skin irritation. Third, fragrance retention and enzyme systems interfere with each other. Current fragrance retention solutions often use the direct addition of free fragrances, which easily leads to fragrance evaporation and loss during storage and washing. Furthermore, fragrance components can inhibit enzyme activity, accelerating enzyme decay and making it difficult to simultaneously achieve efficient stain removal and long-lasting fragrance. In addition, commonly used additives in traditional laundry detergents, such as sodium tripolyphosphate, can easily cause eutrophication of water bodies and have poor environmental compatibility. Alternative additives show significantly reduced efficiency at low temperatures and may also damage clothing or increase system irritation. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the purpose of this invention is to provide a bio-complex enzyme-mediated low-temperature stain removal microcapsule slow-release fragrance laundry detergent.

[0006] The technical effect described in this invention is achieved through the following technical solution: a bio-complex enzyme-mediated low-temperature stain-removing microcapsule slow-release fragrance laundry detergent, comprising the following components by weight: 8-14 parts sodium lauryl ether sulfate, 3-6 parts fatty alcohol polyoxyethylene ether, 4-8 parts cocamidopropyl betaine, 3-5 parts sodium citrate, 1-2 parts tetrasodium glutamate diacetate, 1-1.6 parts anhydrous sodium carbonate, 2-5 parts glycerin, 0.2-0.5 parts sodium carboxymethyl cellulose, 0.2-0.6 parts hydroxyethyl cellulose, 0.02-0.05 parts benzisothiazolinone, 3-6 parts complex enzyme microcapsule slurry, and 2-5 parts sachet microcapsule slurry, with the remainder being deionized water, and the volume adjusted to 100 parts; Furthermore, the preparation of the composite enzyme microcapsule slurry specifically includes the following steps: S1: At 10-20℃, deionized water and glycerol are added to the reaction vessel, sodium citrate is added and dissolved evenly, compound enzyme powder is added and stirred and dispersed evenly, sodium alginate is slowly added and stirred to form a 1.2-1.6 wt% alginate gel solution; then CaCO3 micro powder is added and stirred and dispersed evenly, gluconate-δ-lactone is added and stirred and dissolved evenly to obtain the aqueous phase; S2: Add 0.5–1.5% Span-80 to the white oil, stir and disperse evenly to obtain the oil phase; under a high-speed shearing speed of 2000–3000 rpm, slowly add the aqueous phase of S1 dropwise to the oil phase, so that the D of the emulsion water droplets… 50 With a particle size of 20-60 μm, the emulsion system was kept at room temperature and stirred for 30-60 min to complete the internal gelation. The mixture was then filtered through a 100-200 μm sieve, centrifuged to separate the layers, the oil phase was poured off, and the mixture was centrifuged and washed with water 2-3 times to adjust the solid content, resulting in a composite enzyme microcapsule slurry with a solid content of 25-35%. Further, in step S1, the compound enzyme powder is composed of alkaline protease, amylase, lipase and cellulase in a mass ratio of 1:0.7-0.8:0.4-0.6:0.2; Further, in step S1, the activity of the alkaline protease is 5 × 10⁻⁶. 5 ~8×10 5 U / g; the activity of the amylase is 5 × 10 U / g. 5 ~1×10 6 U / g; the activity of the lipase is 1×10 U / g. 6 ~3×10 6 U / g; the activity of the cellulase is 5 × 10 U / g. 3 ~1×10 4 U / g; Further, in step S1, the mass ratio of the deionized water, glycerol, sodium citrate and compound enzyme powder is 100:6~12:1~2:10~15; Further, in step S1, the mass ratio of the deionized water, CaCO3 micro powder, and glucono-δ-lactone is 100:0.5~1:0.6~1.2; Furthermore, in step S2, the mass ratio of the oil phase to the water phase is 5 to 8:1; Further, in step S2, the enzyme capsule slurry is finely mixed with water and glycerol according to the proportions used in step S1. Furthermore, the preparation of the sachet microcapsule slurry specifically includes the following steps: S101: Dissolve polyvinyl alcohol in deionized water to form a 1-2 wt% PVA aqueous solution. Premix lavender essential oil and isocyanate evenly, then slowly add them to the PVA aqueous solution. Homogenize to allow the oil droplets to form D. 50 With a particle size of 10-25 μm, the temperature was increased to 40-50℃, and 10 wt% diethylenetriamine aqueous solution was slowly added dropwise over 10-20 min. The temperature was maintained for 2-3 h, and the mixture was cooled to room temperature to obtain sachet microcapsule slurry with a solid content of 35-45%. It should be noted that in step S101, the lavender essential oil is a colorless to pale yellow transparent oily liquid; its density at 25℃ is 0.87~0.90g / mL; and its refractive index at 20℃ is 1.458~1.466. It should be noted that, regarding the adjustment of the solid content, if the solid content is low, the sachet slurry should be allowed to stand at ≤25℃ to enrich the microcapsules into a concentrated phase, part of the supernatant should be discarded, and then resuspended with 1wt% PVA aqueous solution and stirred evenly. Further, in step S101, the mass ratio of the lavender essential oil, isocyanate, PVA aqueous solution and diethylenetriamine aqueous solution is 100:10-15:30-50:2-3.5; Furthermore, the preparation of the laundry detergent specifically includes the following steps: S201: Add 35-50 parts of deionized water to the reactor, control the temperature at 30-40℃, slowly add hydroxyethyl cellulose while stirring, stir to fully wet, then add sodium carboxymethyl cellulose and stir until dissolved evenly to obtain the main system; S202: Add sodium citrate, sodium tetrasodium glutamate diacetate, anhydrous sodium carbonate and glycerol to the S201 substrate in sequence, and stir until completely dissolved / uniformly dispersed. Then add sodium lauryl ether sulfate, cocamidopropyl betaine and fatty alcohol polyoxyethylene ether in sequence, and continue stirring until the system has a uniform appearance. Finally, add benzisothiazolinone and make up the remaining deionized water. Adjust the pH to 7.8-8.2 with citric acid to obtain the base solution. S203: Add the compound enzyme microcapsule slurry and the sachet microcapsule slurry to the S202 base solution in sequence, control the temperature to ≤25℃, stir until evenly dispersed, degas under vacuum, filter at 200~300μm, deionize and adjust the volume to obtain the laundry detergent.

[0007] The beneficial effects of this invention are as follows: Compared to existing technologies, this invention constructs an enzyme-protected microdomain using a composite enzyme rapid-release microgel, significantly improving enzyme usability and stain-removing stability under low-temperature conditions. Specifically, the composite enzyme is not simply mixed and added, but is first gently embedded in an alginate gel network to form a dedicated microenvironment. This effectively reduces direct contact between the enzyme and the surfactant system, preservative system, and external oxidizing factors during storage, thereby significantly reducing the risk of inactivation. Upon entering the washing stage, the microgel particles rapidly swell upon contact with water and release the enzyme, allowing the enzyme to quickly reach its working concentration before washing. This effectively compensates for the efficiency loss caused by the decreased reaction rate at low temperatures, achieving a balance between isolation and protection during storage and rapid release during use. This fundamentally improves the consistency and repeatability of stain removal performance at low temperatures.

[0008] To address the technical contradiction between fragrance retention and enzyme systems, this invention employs polyurea-shelled fragrance microcapsules to achieve a delayed / friction-induced slow-release fragrance, naturally offsetting the initial enzyme-based stain removal. Existing fragrance strategies often rely on the direct addition of free fragrance to the system, which not only easily evaporates during storage and washing but also inhibits enzyme activity, accelerating its decay. In contrast, this invention encapsulates lavender essential oil in microcapsules, with the polyurea shell remaining stable during liquid storage and washing, effectively preventing premature fragrance loss. The fragrance is gradually released after the clothes dry or during wear and friction, transforming the fragrance from "instantaneous during washing" to "continuous during wear." More importantly, the microcapsules and enzyme microgels are structurally separated and their release sequences are staggered, ensuring the enzyme fully exerts its stain-removing effect in the initial washing stage while avoiding the inhibition of the enzyme system by the fragrance, ultimately achieving the dual goals of strong stain removal and long-lasting fragrance.

[0009] Addressing the challenge of treating complex stains at low temperatures, this invention constructs a synergistic pathway around the mechanistic bottlenecks of complex stains, significantly improving the balanced treatment capability for typical stains such as protein, starch, and sebum under low-temperature conditions. In low-temperature washing, complex stains formed by the coexistence of oil and protein / starch are the most difficult to treat. Even with the addition of complex enzymes, conventional systems often fail to fully utilize their effectiveness due to oil film shielding and insufficient substrate accessibility. This invention, based on the low-temperature wetting and interface opening provided by the surfactant system, rapidly establishes an effective enzyme activity environment in the pre-wash stage through a fast-release complex enzyme, preferentially weakening the oil film and stain network structure. Subsequently, through the synergistic action of multiple enzymes, it decomposes different substrates in layers, effectively overcoming the technical pain point of complex stains being "difficult to break through the outer layer and difficult to penetrate the interior."

[0010] Furthermore, this invention effectively resolves common contradictions in multi-objective formulation design: on the one hand, enzyme systems require a relatively mild chemical environment to maintain activity, while washing systems require sufficient detergency and storage stability. This invention reduces the impact of environmental stress on enzymes through enzyme microdomain encapsulation technology, avoiding the drawbacks of traditional methods that rely on increasing alkalinity or adding strong surfactants to achieve stain removal effects, and more easily balances the mildness and stain removal power of the washing system. On the other hand, traditional fragrance retention relies on the amount of fragrance used and its volatilization and diffusion, which can easily lead to problems such as fragrance loss, enzyme inhibition, and decreased stability during storage. This invention achieves a change in fragrance utilization through a stable combination of microcapsule shells and friction-triggered release, shifting fragrance retention from ineffective consumption in the formulation stage to effective release in the wearing stage. This reduces the ineffective loss of fragrance in the system and also reduces its negative impact on the enzyme system.

[0011] In summary, this invention, with time-division triggering and structural separation as its core, successfully constructs a synergistic system that integrates low-temperature stain removal, enzyme stabilization, and long-lasting fragrance. Moreover, it achieves industrial-scale and reproducible innovation without introducing complex equipment or high-risk processes. Attached Figure Description

[0012] Figure 1 This is a graph showing the relative activity release rates of various enzymes in the laundry detergent of Example 1 of the present invention; Figure 2 This is a graph showing the relative activity release rates of various enzymes in the laundry detergent of Comparative Example 4 of this invention. Figure 3 The graph shows the residual alkaline protease activity results of laundry detergents in Example 1 and Comparative Examples 1-4 of this invention during storage stability. Figure 4 The graph shows the residual amylase activity of laundry detergent in the storage stability of Example 1 and Comparative Examples 1-4 of the present invention. Figure 5 The graph shows the residual activity of laundry detergent lipase in storage stability for Examples 1 and Comparative Examples 1-4 of the present invention. Figure 6The graph shows the residual cellulase activity of laundry detergent in the storage stability of Example 1 and Comparative Examples 1-4 of the present invention. Detailed Implementation

[0013] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Unless otherwise specified, the raw materials involved in the present invention are all purchased through conventional commercial channels. Experimental methods without specific conditions are conventional methods and conditions well known in the art, or according to the conditions recommended by the instrument manufacturer.

[0014] Example 1: A bio-complex enzyme-mediated low-temperature stain-removing microcapsule sustained-release fragrance laundry detergent, comprising the following components by weight: 12 parts sodium lauryl ether sulfate, 4.5 parts fatty alcohol polyoxyethylene ether, 6 parts cocamidopropyl betaine, 4 parts sodium citrate, 1.5 parts tetrasodium glutamate diacetate, 1.2 parts anhydrous sodium carbonate, 3.5 parts glycerin, 0.4 parts sodium carboxymethyl cellulose, 0.4 parts hydroxyethyl cellulose, 0.03 parts benzisothiazolinone, 4.5 parts complex enzyme microcapsule slurry and 3.5 parts sachet microcapsule slurry, with the remainder being deionized water, and brought to a final volume of 100 parts; The preparation of the composite enzyme microcapsule slurry specifically includes the following steps: S1: At 15℃, add 100g of deionized water and 9g of glycerol to the reaction vessel, add 1.5g of sodium citrate and dissolve evenly, add 13g of compound enzyme powder and stir to disperse evenly, slowly add 1.5g of sodium alginate and stir to form a 1.5wt% alginate gel solution; then add 0.8g of CaCO3 micro powder and stir to disperse evenly, then add 1g of gluconate-δ-lactone and stir to dissolve evenly to obtain the aqueous phase; S2: Add 7g of Span-80 to 700g of white oil, stir and disperse evenly to obtain the oil phase; under a high-speed shear speed of 2500rpm, slowly add 100g of the aqueous phase of S1 to the 700g oil phase, so that the D of the emulsion water droplets... 50 The particle size is 40μm. The emulsion system is kept at room temperature and stirred for 45min to complete the gelation. It is filtered through a 150μm sieve, centrifuged at 5000rpm for 5min to separate the layers, the oil phase is poured off, and the mixture is centrifuged and washed twice with water. The ratio of water and glycerol is adjusted according to the dosage in step S1 to obtain a 30% solid content composite enzyme microcapsule slurry. In step S1, the compound enzyme powder is composed of alkaline protease, amylase, lipase, and cellulase in a mass ratio of 1:0.75:0.5:0.2; the activity of the alkaline protease is 6×10⁻⁶. 5 U / g; the activity of the amylase is 8 × 10⁻⁶ U / g. 5 U / g; the activity of the lipase is 2×10 U / g.6 U / g; the activity of the cellulase is 8 × 10⁻⁶ U / g. 3 U / g; The preparation of the sachet microcapsule slurry specifically includes the following steps: S101: Dissolve 0.6g of polyvinyl alcohol in 40g of deionized water to form a 1.5wt% PVA aqueous solution. Premix 100g of lavender essential oil and 12g of isocyanate evenly, then slowly add the mixture to the 40g PVA aqueous solution. Homogenize to allow the oil droplets to form a D0. 50 With a particle size of 15 μm, the temperature was increased to 45 °C, and 3 g of 10 wt% diethylenetriamine aqueous solution was slowly added dropwise over 15 min. The temperature was maintained for 2.5 h, and the mixture was cooled to room temperature to obtain a sachet microcapsule slurry with a solid content of 40%. The preparation of the laundry detergent specifically includes the following steps: S201: Add 45 parts of deionized water to the reactor, control the temperature at 35℃, slowly add hydroxyethyl cellulose while stirring, stir to fully wet, then add sodium carboxymethyl cellulose and stir until dissolved evenly to obtain the main system; S202: Add sodium citrate, sodium tetrasodium glutamate diacetate, anhydrous sodium carbonate and glycerol to the S201 substrate in sequence, and stir until completely dissolved / uniformly dispersed. Then add sodium lauryl ether sulfate, cocamidopropyl betaine and fatty alcohol polyoxyethylene ether in sequence, and continue stirring until the system has a uniform appearance. Finally, add benzisothiazolinone and add the remaining deionized water. Adjust the pH to 8 with citric acid to obtain the base solution. S203: Add the compound enzyme microcapsule slurry and the sachet microcapsule slurry to the S202 base solution in sequence, control the temperature to ≤25℃, stir until evenly dispersed, degas under vacuum, filter at 250μm, deionize and adjust the volume to obtain the laundry detergent.

[0015] Example 2: A bio-complex enzyme-mediated low-temperature stain-removing microcapsule sustained-release fragrance laundry detergent, comprising the following components by weight: 14 parts sodium lauryl ether sulfate, 6 parts fatty alcohol polyoxyethylene ether, 8 parts cocamidopropyl betaine, 5 parts sodium citrate, 2 parts tetrasodium glutamate diacetate, 1.6 parts anhydrous sodium carbonate, 5 parts glycerin, 0.5 parts sodium carboxymethyl cellulose, 0.6 parts hydroxyethyl cellulose, 0.05 parts benzisothiazolinone, 6 parts complex enzyme microcapsule slurry and 5 parts sachet microcapsule slurry, with the remainder being deionized water, and brought to a final volume of 100 parts; The preparation of the composite enzyme microcapsule slurry specifically includes the following steps: S1: At 20℃, add 100g of deionized water and 12g of glycerol to the reaction vessel, add 2g of sodium citrate and dissolve evenly, add 15g of compound enzyme powder and stir to disperse evenly, slowly add 1.6g of sodium alginate and stir to form a 1.6 wt% alginate gel solution; then add 1g of CaCO3 micro powder and stir to disperse evenly, then add 1.2g of gluconate-δ-lactone and stir to dissolve evenly to obtain the aqueous phase; S2: Add 12g of Span-80 to 800g of white oil, stir and disperse evenly to obtain the oil phase; under a high-speed shearing speed of 3000rpm, slowly add 100g of the aqueous phase of S1 to the 800g oil phase, so that the D of the emulsion water droplets... 50 With a particle size of 20 μm, the emulsion system was kept at room temperature and stirred for 60 min to allow the internal gelation to be completed. The mixture was filtered through a 100 μm sieve, centrifuged at 5000 rpm for 5 min to separate the layers, the oil phase was poured off, and the mixture was centrifuged and washed with water 3 times. The ratio of water and glycerol was adjusted according to the dosage in step S1 to obtain a composite enzyme microcapsule slurry with a solid content of 35%. In step S1, the compound enzyme powder is composed of alkaline protease, amylase, lipase, and cellulase in a mass ratio of 1:0.7:0.4:0.2; the activity of the alkaline protease is 8 × 10⁻⁶. 5 U / g; the activity of the amylase is 1×10 U / g. 6 U / g; the activity of the lipase is 3×10 U / g. 6 U / g; the activity of the cellulase is 1×10 U / g. 4 U / g; The preparation of the sachet microcapsule slurry specifically includes the following steps: S101: Dissolve 1g of polyvinyl alcohol in 50g of deionized water to form a 2wt% PVA aqueous solution. Premix 100g of lavender essential oil and 15g of isocyanate evenly, then slowly add them to the 50g PVA aqueous solution. Homogenize to allow the oil droplets to form D. 50 With a particle size of 10 μm, the temperature was increased to 50 °C, and 3.5 g of 10 wt% diethylenetriamine aqueous solution was slowly added dropwise over 20 min. The temperature was maintained for 3 h, and the mixture was cooled to room temperature to obtain a sachet microcapsule slurry with a solid content of 45%. The preparation of the laundry detergent specifically includes the following steps: S201: Add 50 parts of deionized water to the reactor, control the temperature at 30°C, slowly add hydroxyethyl cellulose while stirring, stir to fully wet, then add sodium carboxymethyl cellulose and stir until dissolved evenly to obtain the main system; S202: Add sodium citrate, sodium tetrasodium glutamate diacetate, anhydrous sodium carbonate and glycerol to the S201 substrate in sequence, and stir until completely dissolved / uniformly dispersed. Then add sodium lauryl ether sulfate, cocamidopropyl betaine and fatty alcohol polyoxyethylene ether in sequence, and continue stirring until the system has a uniform appearance. Finally, add benzisothiazolinone and make up the remaining deionized water. Adjust the pH to 7.8 with citric acid to obtain the base solution. S203: Add the compound enzyme microcapsule slurry and the sachet microcapsule slurry to the S202 base solution in sequence, control the temperature to ≤25℃, stir until evenly dispersed, degas under vacuum, filter at 200μm, deionize and adjust the volume to obtain the laundry detergent.

[0016] Example 3: A bio-complex enzyme-mediated low-temperature stain-removing microcapsule sustained-release fragrance laundry detergent, comprising the following components by weight: 8 parts sodium lauryl ether sulfate, 3 parts fatty alcohol polyoxyethylene ether, 4 parts cocamidopropyl betaine, 3 parts sodium citrate, 1 part tetrasodium glutamate diacetate, 1 part anhydrous sodium carbonate, 2-5 parts glycerin, 0.2 parts sodium carboxymethyl cellulose, 0.2 parts hydroxyethyl cellulose, 0.02 parts benzisothiazolinone, 3 parts complex enzyme microcapsule slurry and 2 parts sachet microcapsule slurry, with the remainder being deionized water, and brought to a final volume of 100 parts; The preparation of the composite enzyme microcapsule slurry specifically includes the following steps: S1: At 10℃, add 100g of deionized water and 6g of glycerol to the reaction vessel, add 1g of sodium citrate and dissolve evenly, add 10g of compound enzyme powder and stir to disperse evenly, slowly add 1.2g of sodium alginate and stir to form a 1.2wt% alginate gel solution; then add 0.5g of CaCO3 micro powder and stir to disperse evenly, then add 0.6g of gluconate-δ-lactone and stir to dissolve evenly to obtain the aqueous phase; S2: Add 2.5g Span-80 to 500g of white oil, stir and disperse evenly to obtain the oil phase; under a high-speed shear speed of 2000rpm, slowly add 100g of the aqueous phase of S1 to 500g of the oil phase, so that the D of the emulsion water droplets... 50 The particle size is 60μm. The emulsion system is kept at room temperature and stirred for 30 minutes to complete the gelation. It is then filtered through a 200μm sieve, centrifuged at 5000rpm for 5 minutes to separate the layers, the oil phase is poured off, and the mixture is centrifuged and washed twice with water. The ratio of water and glycerol is adjusted according to the dosage in step S1 to obtain a composite enzyme microcapsule slurry with a solid content of 25%. In step S1, the compound enzyme powder is composed of alkaline protease, amylase, lipase, and cellulase in a mass ratio of 1:0.8:0.6:0.2; the activity of the alkaline protease is 5 × 10⁻⁶. 5 U / g; the activity of the amylase is 5 × 10 U / g. 5 U / g; the activity of the lipase is 1×10 U / g.6 U / g; the activity of the cellulase is 5 × 10 U / g. 3 U / g; The preparation of the sachet microcapsule slurry specifically includes the following steps: S101: Dissolve 0.5g of polyvinyl alcohol in 50g of deionized water to form a 1wt% PVA aqueous solution. Premix 100g of lavender essential oil and 10g of isocyanate evenly, then slowly add them to 30g of the PVA aqueous solution. Homogenize to allow the oil droplets to form D. 50 With a particle size of 25 μm, the temperature was increased to 40 °C, and 2 g of 10 wt% diethylenetriamine aqueous solution was slowly added dropwise over 10 min. The temperature was maintained for 2 h, and the mixture was cooled to room temperature to obtain a sachet microcapsule slurry with a solid content of 35%. The preparation of the laundry detergent specifically includes the following steps: S201: Add 35 parts of deionized water to the reactor, control the temperature at 40°C, slowly add hydroxyethyl cellulose while stirring, stir to fully wet, then add sodium carboxymethyl cellulose and stir until dissolved evenly to obtain the main system; S202: Add sodium citrate, sodium tetrasodium glutamate diacetate, anhydrous sodium carbonate and glycerol to the S201 substrate in sequence, and stir until completely dissolved / uniformly dispersed. Then add sodium lauryl ether sulfate, cocamidopropyl betaine and fatty alcohol polyoxyethylene ether in sequence, and continue stirring until the system has a uniform appearance. Finally, add benzisothiazolinone and make up the remaining deionized water. Adjust the pH to 8.2 with citric acid to obtain the base solution. S203: Add the compound enzyme microcapsule slurry and the sachet microcapsule slurry to the S202 base solution in sequence, control the temperature to ≤25℃, stir until evenly dispersed, vacuum degas, filter at 300μm, deionize and adjust the volume to obtain the laundry detergent.

[0017] Comparative Example 1: No compound enzyme microcapsule slurry was added in Comparative Example 1: Instead, the same effective amount of compound enzyme powder as in Example 1 was directly added to the S202 base liquid and dispersed evenly; the remaining raw material ratios and step parameters were kept the same as in Example 1.

[0018] Comparative Example 2: No sachet microcapsule slurry was added in Comparative Example 2; the same effective amount of lavender essential oil as in Example 1 was directly added to the S202 base liquid and dispersed evenly; the remaining raw material ratios and step parameters were the same as in Example 1.

[0019] Comparative Example 3: In Comparative Example 3, lavender essential oil was directly added to the sachet microcapsule slurry, so that the fragrance and enzyme were in the same microparticle system; the remaining raw material ratios and step parameters were consistent with those in Example 1.

[0020] Comparative Example 4: The concentration of sodium alginate in Comparative Example 4 was increased to 3 wt%; the remaining raw material ratios and step parameters remained the same as in Example 1.

[0021] Verification of low-temperature stain removal effect: Referring to GB / T 13174-2021, the sample laundry detergent (Examples 1-3 and Comparative Examples 1-4) were diluted to a concentration of 0.2%, and the detergent solution was prepared using 250 mg / kg hard water (calcium-magnesium ion ratio 6:4). Standard carbon black oil-stained cloth, protein-stained cloth, and sebum-stained cloth test pieces (10cm×10cm) were taken respectively and washed for 20 minutes at 120 rpm in a vertical stain removal tester at 15℃. After washing, the cloth was rinsed and dried, and the reflectance was measured using a whiteness meter conforming to JJG 512. The stain removal rate (%) was calculated as follows: (Reflectance of stained cloth after washing - Reflectance of stained cloth before washing after contamination) / (Reflectance of blank control group cloth - Reflectance of stained cloth before washing after contamination) × 100%. The test was repeated 3 times, and the average value of the results was taken. The test results are shown in Table 1 below.

[0022] Table 1. Low-temperature stain removal rate results of laundry detergents in the examples and comparative examples.

[0023] Based on the results in Table 1, the examples performed best on all three types of standard stains, exhibiting a more significant improvement in protein / sebum stains and a relatively mild improvement in charcoal black stains. This is consistent with the timing-triggered mechanism of this invention: after the complex enzyme is encapsulated in calcium alginate microgel particles, its direct contact with surfactants, chelating agents, and fragrance components is reduced during storage, and it can rapidly release enzymes in the early stages to establish an effective enzyme concentration during use, thus resulting in a more prominent improvement on protein and sebum stains; while the improvement on charcoal black stains is more controlled by interface wetting and particle desorption, so the gain is relatively gradual. In Comparative Example 4, increasing the sodium alginate concentration resulted in a significant slow release of enzyme particles, but the available enzyme activity was insufficient in the initial stage within 20 minutes, and the removal of protein and sebum stains declined significantly. In Comparative Example 1, after changing to free enzymes, the effect of washing was still somewhat effective, but lower than that of Example 1. In Comparative Example 2, changing the sachet to free essential oils had a smaller impact on stain removal, but still slightly hampered it. In Comparative Example 3, placing the fragrance and enzymes in the same system significantly reduced stain removal, indicating that spatial separation and staggered release effectively avoid enzyme inhibition and interface interference, thereby achieving a synergistic effect of low-temperature stain removal and fragrance retention.

[0024] Enzyme release curve verification: A 500 mL volume of washing system (same temperature and dosage as the low-temperature stain removal verification above) was used. Test samples were the laundry detergents from Example 1 and Comparative Example 4. Washing solutions were collected at 5, 10, 15, and 30 minutes. After centrifugation to remove particulates, the activities of alkaline protease, amylase, lipase, and cellulase in the supernatant were measured. The relative activity release rate (%) was calculated as: (Enzyme activity at sampling point / Enzyme activity at 30 min sampling point) × 100%. Results are as follows: Figure 1-2 As shown.

[0025] based on Figure 1 and Figure 2 Results analysis showed that Example 1, using a calcium alginate microgel system with moderate cross-linking density, allowed the microparticles to swell more easily in the low-temperature washing medium and form faster diffusion channels. Therefore, the detectable enzyme activity in the supernatant rapidly increased and approached a plateau within 5-15 minutes. Comparative Example 4, by increasing the sodium alginate concentration to 3 wt%, resulted in a denser gel network, increased diffusion resistance, and significantly delayed enzyme migration from the microparticles to the external phase, leading to insufficient usable enzyme activity in the initial stage. Considering the 20-minute washing time for the low-temperature stain removal test in Table 1, the insufficient release in the crucial initial stage (5-15 minutes) of Comparative Example 4 directly resulted in a significant decrease in the stain removal rate of protein-stained and sebum-stained cloths. Example 1, however, performed optimally due to its rapid enzyme release in the initial stage, establishing an effective activity concentration.

[0026] Storage stability verification: The laundry detergents of Example 1 and Comparative Examples 1-4 were placed in an environment of 40°C. Samples were taken at days 0, 7, 14, and 28, and the remaining activity (%) of the four enzymes was measured as follows: = enzyme activity after storage / initial enzyme activity × 100%. The results are as follows: Figure 3-6 As shown in Table 2 below, the changes in appearance and odor were recorded, including whether stratification, sedimentation, and turbidity occurred, and whether any unpleasant odors were produced.

[0027] Table 2. Results of appearance and odor changes of the laundry detergents in the examples and comparative examples.

[0028] based on Figure 3-6 Analysis of the results in Table 2 shows that the four enzymes in Example 1 maintained higher residual activity overall. Firstly, the complex enzyme was encapsulated in calcium alginate microgel, forming a micro-domain protection that reduced direct contact between the enzyme and surfactants / chelating agents / oxidative environments. Secondly, the sachet microcapsules spatially separated the lavender essential oil from the enzyme system, achieving staggered release and avoiding the inhibition and accelerated inactivation of the enzyme by the fragrance and its hydrophobic properties. In Comparative Example 1, after removing the encapsulation, the enzyme was directly exposed to the formulation environment, making it more susceptible to inactivation under thermal stress, thus resulting in a faster decline in residual activity. In Comparative Example 2, replacing the sachet with free essential oil led to more significant fluctuations in fragrance volatility and compatibility during storage, causing both aroma decay and a negative impact on enzyme stability. In Comparative Example 3, placing the fragrance and enzyme in the same system resulted in a superposition of enzyme inhibition and phase separation risks, manifesting as the fastest enzyme activity decay and the most obvious aging of appearance and odor. Comparative Example 4, due to its denser gel network, provided stronger protection for the enzyme during storage, achieving higher residual activity than Example 1, but its release kinetics were slower, accompanied by system thickening and a slight sedimentation tendency.

[0029] Fragrance retention effect verification: Cotton fabrics from Example 1 and Comparative Examples 2-3, after being washed and dried for low-temperature stain removal effect verification, were evaluated for fragrance retention at 0h, 24h, and 72h after drying. Before each evaluation point, the fabric was rubbed 50 times at a fixed number of times, followed by olfactory evaluation. The evaluation method is recommended to be a blind sensory evaluation with 10 reviewers. The scoring scale is 1-5 points (1 point: almost blank fabric, almost no smell or only a very weak and unidentifiable fragrance; 2 points: the fragrance can be identified when close, but the intensity is low and it dissipates quickly after leaving; 3 points: the fragrance can be clearly smelled even without being very close, the fragrance is clear, and the persistence can be perceived; 4 points: the fragrance is strong and the diffusion is obvious, and it can be smelled as soon as the fabric is picked up; 5 points: the fragrance is very strong and full, and the diffusion is very obvious). The results are shown in Table 3 below.

[0030] Table 3. Fragrance retention rating results of laundry detergents in the examples and comparative examples.

[0031] Based on the results in Table 3, Example 1 showed a slower decay in fragrance retention score from 0-72 hours, maintaining a clear and perceptible fragrance intensity even after 72 hours. This is likely due to the use of polyurea-shell microcapsules to encapsulate lavender essential oil, preventing premature evaporation during washing and drying, and allowing for continued release triggered by fabric friction after drying. Comparative Example 2 initially scored slightly higher, but the scores decreased significantly at 24 and 72 hours. This is likely because the lavender essential oil was added in a free state, resulting in ample initial fragrance release, but significant evaporation and washing losses led to rapid fragrance decay. Comparative Example 3 had a lower initial fragrance retention score and faster decay later. This is likely because placing the fragrance and enzyme in the same microparticle system made the fragrance more prone to leakage or deterioration during storage / washing, compounded by fluctuations in system compatibility.

[0032] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A bio-complex enzyme-mediated low-temperature stain-removing microcapsule slow-release fragrance laundry detergent, characterized in that, Its composition includes the following components by weight: 8-14 parts sodium lauryl ether sulfate, 3-6 parts fatty alcohol polyoxyethylene ether, 4-8 parts cocamidopropyl betaine, 3-5 parts sodium citrate, 1-2 parts sodium tetrasodium glutamate diacetate, 1-1.6 parts anhydrous sodium carbonate, 2-5 parts glycerol, 0.2-0.5 parts sodium carboxymethyl cellulose, 0.2-0.6 parts hydroxyethyl cellulose, 0.02-0.05 parts benzisothiazolinone, 3-6 parts compound enzyme microcapsule slurry, and 2-5 parts sachet microcapsule slurry, with the balance being deionized water, and the volume is adjusted to 100 parts.

2. The bio-complex enzyme-mediated low-temperature stain-removing microcapsule slow-release fragrance laundry detergent according to claim 1, characterized in that, The preparation of the composite enzyme microcapsule slurry specifically includes the following steps: S1: Add deionized water and glycerol to the reaction vessel, add sodium citrate and dissolve evenly, add compound enzyme powder and stir to disperse evenly, slowly add sodium alginate and stir to form an alginate gel solution; then add CaCO3 micro powder and stir to disperse evenly, then add gluconate-δ-lactone and stir to dissolve evenly to obtain the aqueous phase; S2: Add Span-80 to the white oil and stir to disperse evenly to obtain the oil phase; under high-speed shearing, slowly add the aqueous phase of S1 to the oil phase, maintain the emulsion system at room temperature and continue stirring and heat treatment to complete the internal gelation, filter through a sieve, centrifuge to separate the layers, pour out the oil phase, centrifuge and wash with water, adjust the solid content, and obtain the composite enzyme microcapsule slurry.

3. The bio-complex enzyme-mediated low-temperature stain-removing microcapsule slow-release fragrance laundry detergent according to claim 1, characterized in that, In step S1, the compound enzyme powder is composed of alkaline protease, amylase, lipase and cellulase in a mass ratio of 1:0.7-0.8:0.4-0.6:0.

2.

4. The bio-complex enzyme-mediated low-temperature stain-removing microcapsule sustained-release fragrance laundry detergent according to claim 1, characterized in that, In step S1, the activity of the alkaline protease is 5 × 10⁻⁶. 5 ~8×10 5 U / g; the activity of the amylase is 5 × 10⁻⁶ U / g. 5 ~1×10 6 U / g; the activity of the lipase is 1×10 U / g. 6 ~3×10 6 U / g; the activity of the cellulase is 5 × 10 U / g. 3 ~1×10 4 U / g.

5. The bio-complex enzyme-mediated low-temperature stain-removing microcapsule sustained-release fragrance laundry detergent according to claim 1, characterized in that, In step S1, the mass ratio of deionized water, glycerol, sodium citrate and compound enzyme powder is 100:6-12:1-2:10-15.

6. The bio-complex enzyme-mediated low-temperature stain-removing microcapsule sustained-release fragrance laundry detergent according to claim 1, characterized in that, In step S1, the mass ratio of deionized water, CaCO3 micro powder and gluconate-δ-lactone is 100:0.5~1:0.6~1.

2.

7. The bio-complex enzyme-mediated low-temperature stain-removing microcapsule sustained-release fragrance laundry detergent according to claim 1, characterized in that, In step S2, the mass ratio of the oil phase to the water phase is 5 to 8:

1.

8. The bio-complex enzyme-mediated low-temperature stain-removing microcapsule sustained-release fragrance laundry detergent according to claim 1, characterized in that, The preparation of the sachet microcapsule slurry specifically includes the following steps: S101: Polyvinyl alcohol is dissolved in deionized water to form a PVA aqueous solution. Lavender essential oil and isocyanate are premixed evenly and then slowly added to the PVA aqueous solution. The mixture is homogenized, the temperature is increased, and diethylenetriamine aqueous solution is slowly added dropwise. The temperature is maintained for the reaction. The mixture is then cooled to room temperature to obtain the sachet microcapsule slurry.

9. The bio-complex enzyme-mediated low-temperature stain-removing microcapsule sustained-release fragrance laundry detergent according to claim 1, characterized in that, In step S101, the mass ratio of the lavender essential oil, isocyanate, PVA aqueous solution and diethylenetriamine aqueous solution is 100:10-15:30-50:2-3.

5.

10. The bio-complex enzyme-mediated low-temperature stain-removing microcapsule sustained-release fragrance laundry detergent according to claim 1, characterized in that, The preparation of the laundry detergent specifically includes the following steps: S201: Add deionized water to the reactor, control the temperature, slowly add hydroxyethyl cellulose while stirring, stir to fully wet, then add sodium carboxymethyl cellulose and stir until dissolved evenly to obtain the main system; S202: Add sodium citrate, sodium tetrasodium glutamate diacetate, anhydrous sodium carbonate and glycerol to the S201 main solution in sequence, and stir until completely dissolved / uniformly dispersed. Then add sodium lauryl ether sulfate, cocamidopropyl betaine and fatty alcohol polyoxyethylene ether in sequence, and continue stirring until the system has a uniform appearance. Finally, add benzisothiazolinone and make up the remaining deionized water. Adjust the pH with citric acid to obtain the base solution. S203: Add the compound enzyme microcapsule slurry and the sachet microcapsule slurry to the S202 base liquid in sequence, control the temperature, stir until evenly dispersed, vacuum degas, filter, deionize and adjust the volume to obtain the laundry detergent.

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