A kind of biological functional water-based synthetic leather that can lastly emit natural lavender flavor

Abstract

This invention provides a biofunctional water-based synthetic leather with a long-lasting natural lavender scent, belonging to the field of water-based synthetic leather technology. The preparation method of the synthetic leather includes preparing microcapsules B containing lavender essential oil. The preparation of microcapsules B includes modified microcrystalline cellulose and encapsulation. The encapsulation involves mixing modified microcrystalline cellulose with sodium alginate and gum arabic, adding deionized water and stirring to obtain a mixture. Lavender essential oil and cocamidopropyl betaine are added to the mixture, and the mixture is placed in a sealed container for sealing treatment for 30-36 minutes at a pressure of 0.4-0.6 MPa. After treatment, the mixture is frozen at -38 to -35°C and then naturally restored to room temperature to obtain microcapsules B containing lavender essential oil. The water-based synthetic leather prepared by this invention has good water permeability, excellent strength, and superior resistance to hydrolysis and low temperatures.

Description

Technical Field

[0001] This invention belongs to the field of synthetic leather technology, specifically relating to a biofunctional water-based synthetic leather that emits a long-lasting natural lavender scent. Background Technology

[0002] With social development and the improvement of people's living standards, the requirements for consumer goods are getting higher and higher. Natural leather is one of the popular consumer goods. Due to the scarcity of raw materials and the uneven supply and demand, leather products are expensive, which limits their popularization and promotion.

[0003] To meet consumer demand, synthetic leather has emerged as an alternative material. Polyurethane synthetic leather has a soft, leather-like appearance, excellent adhesion to substrates, is washable, easy to process, and inexpensive. It is the most ideal substitute for natural leather and is widely used in clothing, footwear, bags, furniture and other industries.

[0004] Currently, solvent-based polyurethane synthetic leather accounts for the largest market share among polyurethane synthetic leathers. However, solvent-based polyurethane requires a large amount of organic solvents during the production process, such as toluene, dimethylformamide, acetone, and methyl ethyl ketone. These solvents have significant toxic effects, and they are difficult to completely recover. When released into the air, they not only pollute the environment but also endanger human health.

[0005] Waterborne polyurethane uses water as a dispersion medium and has advantages such as being non-toxic, environmentally friendly, and safe, making it the best alternative to solvent-based polyurethane.

[0006] In the process of preparing waterborne polyurethane, existing technologies typically introduce hydrophilic groups such as carboxyl groups to improve the water permeability of synthetic leather. However, while enhancing water permeability, these technologies usually reduce physical properties such as peel strength, tear strength, and tensile strength, and also result in poor water resistance. Furthermore, current waterborne synthetic leathers all suffer from poor low-temperature resistance.

[0007] Therefore, water-based synthetic leather produced by existing technologies has the following problems:

[0008] 1. While improving water permeability, it reduces physical properties such as peel strength, tear strength, and tensile strength;

[0009] 2. Poor water resistance;

[0010] 3. Poor low-temperature performance. Summary of the Invention

[0011] To address the technical problems existing in the prior art, the present invention provides a biofunctional water-based synthetic leather that emits a long-lasting natural lavender scent, while simultaneously solving the following technical problems:

[0012] 1. While improving water permeability, ensure physical properties such as peel strength, tear strength, and tensile strength;

[0013] 2. Excellent water resistance;

[0014] 3. Excellent low-temperature resistance.

[0015] To address the aforementioned technical problems, the present invention adopts the following technical solution:

[0016] A biofunctional water-based synthetic leather that emits a long-lasting natural lavender scent, the preparation method of which specifically includes the following steps:

[0017] 1. Preparation of lavender essential oil

[0018] Dried lavender flowers are crushed to obtain lavender fragments. Then, 6-8 times the volume of deionized water is added, and the mixture is stirred evenly. The mixture is then subjected to ultrasonic treatment at a temperature of 30-34℃ for 8-12 minutes. After ultrasonic treatment, the mixture is placed at 120-130℃ for distillation for 1.7-2.2 hours. The distillate is salted out with sodium chloride solution and then allowed to stand at 3.6-4.5℃ for 7.7-8.2 hours. After standing, the mixture is separated using a separatory funnel to obtain lavender essential oil.

[0019] The sodium chloride solution has a mass concentration of 3.8-4.2%.

[0020] 2. Preparation of microcapsules containing lavender essential oil A

[0021] (1) Preparation of wall material

[0022] Gelatin and maltodextrin are mixed, and then deionized water is added and stirred for 13-17 minutes at a speed of 120-135 rpm at a temperature of 40-44°C. After stirring, ethyl cellulose and sodium dodecyl sulfate are added and ultrasonically vibrated for 6-8 minutes at a frequency of 20-25 kHz. After the vibration treatment, the wall material solution is obtained.

[0023] The mass ratio of gelatin, maltodextrin, deionized water, ethyl cellulose and sodium lauryl sulfate is 3.6-4.0:2.0-2.4:35-40:0.6-0.9:0.3-0.5.

[0024] (2) Preparation of core material

[0025] Mix lavender essential oil with soybean lecithin, then stir at a speed of 142-155 rpm for 20-25 minutes. The core material is obtained after stirring.

[0026] The mass ratio of lavender essential oil to soybean lecithin is 10-12:2.5-2.8;

[0027] (3) Mixing

[0028] The wall material and core material were mixed, and then ethylene bis-stearamide was added for homogenization. The homogenization was performed 3 times, with a homogenization pressure of 3.2-3.7 MPa and a homogenization time of 4-6 min each time. After homogenization, spray drying was performed, with the inlet air temperature of the spray tower controlled at 136-140℃ and the outlet air temperature at 68-72℃. After drying, the mixture was cooled to room temperature and passed through an 80-120 mesh sieve to obtain microcapsules A containing lavender essential oil.

[0029] The mass ratio of the wall material, core material and ethylene bis-stearamide is 10-13:1.0-1.3:0.2-0.5.

[0030] 3. Preparation of microcapsules containing lavender essential oil B

[0031] (1) Modified microcrystalline cellulose

[0032] Microcrystalline cellulose was placed in 2-4 times its volume of sodium hydroxide solution and stirred for 4-6 minutes. After stirring, it was washed and dried to obtain alkali-impregnated microcrystalline cellulose. The alkali-impregnated microcrystalline cellulose was then impregnated in 3-5 times its volume of impregnation solution at a temperature of 38-42℃ for 22-28 minutes. Pressure was applied during impregnation, and the impregnation pressure was controlled at 0.6-0.8 MPa. After impregnation, the temperature was first lowered to 4.0-4.5℃ at a rate of 0.8-1.2℃ / min, and then pre-cooled and dried at a temperature of -15 to -11℃ for 17-20 minutes. After pre-cooling, freeze-drying was performed at a temperature of -30 to -25℃ for 20-30 minutes. After freeze-drying, the mixture was allowed to return to room temperature naturally to obtain modified microcrystalline cellulose.

[0033] The sodium hydroxide solution has a mass concentration of 13-15%;

[0034] The impregnation solution is a mixture of sodium hydroxypropyl cellulose, polyvinylpyrrolidone, and deionized water, wherein the mass ratio of sodium hydroxypropyl cellulose, polyvinylpyrrolidone, and deionized water is 4.4-4.7:3.0-3.3:35-40.

[0035] (2) Embedding

[0036] Modified microcrystalline cellulose was mixed with sodium alginate and gum arabic, and then deionized water was added and stirred for 15-20 minutes at a speed of 178-190 rpm and a temperature of 45-51℃. After stirring, a mixture was obtained. Lavender essential oil and cocamidopropyl betaine were added to the mixture, and the mixture was placed in a sealed container for sealing treatment for 30-36 minutes at a pressure of 0.4-0.6 MPa. After sealing treatment, the mixture was frozen at a temperature of -38 to -35℃ and then allowed to naturally return to room temperature to obtain microcapsules B containing lavender essential oil.

[0037] The mass ratio of the modified microcrystalline cellulose, sodium alginate, gum arabic, and deionized water is 11-13:7-9:13-15:106-115;

[0038] The mass ratio of the mixture, lavender essential oil and cocamidopropyl betaine is 73-80:8.2-8.8:1.1-1.5.

[0039] 4. Preparation of waterborne polyurethane emulsion

[0040] Polyethylene glycol was vacuum dehydrated at 117-122℃ for 1.7-2.2 hours. The temperature was then lowered to 53-57℃, and diisocyanate and dibutyltin dilaurate were added for a reaction at 82-86℃ for 1.2-1.6 hours. Then, 1,3-propanediol, dimethylolpropionic acid, and trimethylolpropane were added, and the reaction continued for 2.2-2.7 hours. The temperature was then lowered to 52-56℃, and acetone was added as a viscosity reducer. The temperature was then lowered to 32-38℃, and triethylamine was added as a neutralizing agent. The reaction was carried out for 4-6 minutes, and the temperature was lowered to 25-27℃. Deionized water was added, and the mixture was stirred for 20-32 minutes to obtain an aqueous polyurethane emulsion.

[0041] The mass ratio of polyethylene glycol, diisocyanate, dibutyltin dilaurate, 1,3-propanediol, dimethylolpropionic acid, trimethylolpropane, acetone, triethylamine, and deionized water is 108-112:27-31:0.23-0.27:2.3-2.5:4.6-4.8:0.26-0.30:87-93:4.1-4.5:342-350.

[0042] 5. Preparation of slurry

[0043] Waterborne polyurethane resin, microcapsules A containing lavender essential oil, dimethyl silicone oil, hydroxymethyl cellulose, sodium stearate, activated carbon black and deionized water are mixed and then ball-milled for 30-34 minutes at a speed of 775-785 rpm, with a ball-to-material ratio of 2-6:1 and a temperature of 30-35℃. The bottom slurry is obtained after the ball milling is completed.

[0044] Waterborne polyurethane resin, microcapsules B containing lavender essential oil, dimethyl silicone oil, hydroxymethyl cellulose, sodium stearate, pigment, activated carbon black and deionized water are mixed and then ball-milled for 38-45 minutes at a speed of 815-823 rpm, with a ball-to-material ratio of 6-10:1 and a temperature of 32-38℃. The surface slurry is obtained after ball milling.

[0045] In the preparation of the bottom slurry, the mass ratio of the waterborne polyurethane resin, microcapsules A containing lavender essential oil, dimethyl silicone oil, hydroxymethyl cellulose, sodium stearate, activated carbon black, and deionized water is 92-96:5.5-5.9:1.2-1.4:2.0-2.4:1.7-1.9:2.7-3.3:16-20.

[0046] In the preparation of the surface layer slurry, the mass ratio of the waterborne polyurethane resin, microcapsules B containing lavender essential oil, dimethyl silicone oil, hydroxymethyl cellulose, sodium stearate, pigment, activated carbon black, and deionized water is 107-113:5.8-6.2:1.4-1.6:2.3-2.9:1.8-2.2:4.8-5.2:4.1-4.5:20-25;

[0047] The method for preparing activated carbon black is as follows: precipitated silica is calcined at 115-125℃ for 18-22 min, then heated to 176-184℃ at a rate of 3.8-4.2℃ / min and calcined at 176-184℃ for 22-30 min, then heated to 246-254℃ at a rate of 1.8-2.2℃ / min and calcined at 246-254℃ for 30-34 min. After calcination, the silica is cooled to room temperature, and deionized water, polyethylene glycol, and citric acid are added. Then, plasma treatment is performed for 23-27 s, at a frequency of 10-14 kHz, and with a power of 30-34 W. After treatment, the silica is dried to obtain activated carbon black.

[0048] The mass ratio of carbon black, deionized water, polyethylene glycol, and citric acid is 10-14:53-62:2.1-2.5:2.8-3.2.

[0049] 6. Coating

[0050] The surface layer slurry is coated under the release paper, with a coating amount of 95-105 g / m². 2 The top layer is obtained by drying at 107-114℃. A TPU adhesive is then applied below the top layer to form the adhesive layer. Finally, a base coat of 97-103 g / m² is applied below the adhesive layer. 2The bottom layer is dried at 108-112℃. The non-woven fabric is preheated at 95-105℃ and then bonded to the bottom layer with a bonding pressure of 0.5-0.7MPa. After bonding, it is dried at 103-107℃. Finally, it is cooled and peeled off to obtain water-based synthetic leather.

[0051] Compared with the prior art, the present invention achieves the following beneficial effects:

[0052] 1. This invention employs a specific method to prepare microcapsules A containing lavender essential oil, which avoids the loss of lavender essential oil during post-processing; and a specific method to prepare microcapsules B containing lavender essential oil, which modifies microcrystalline cellulose, resulting in good curing effect and ensuring the stability of the microcapsules. The combination of the two microcapsules effectively ensures the sustained-release performance of the essential oil and avoids the impact of directly adding the essential oil on the strength properties of synthetic leather, while enhancing the antibacterial durability and fragrance emission properties. Activated carbon black is added during the preparation of the slurry, which, combined with a specific ball milling process, enhances the tensile strength, peel strength, tear strength, and bursting strength of the synthetic leather, improves its structural stability, reduces strength loss at low temperatures and after hydrolysis, and ensures water permeability.

[0053] 2. The water-based synthetic leather produced by this invention has a natural lavender scent that can be smelled from 5cm away, and the fragrance emission performance lasts for more than 2 years;

[0054] 3. The water-based synthetic leather prepared by this invention has an inhibition rate of 94.2-95.2% against Escherichia coli, 93.5-94.3% against Staphylococcus aureus, and 93.1-95.0% against Candida albicans.

[0055] After being placed in an environment with a temperature of 26℃ and a humidity of 45% for 6 years, the inhibition rate against Escherichia coli was 84.2-87.5%, against Staphylococcus aureus was 84.4-85.6%, and against Candida albicans was 85.8-86.1%.

[0056] 4. The water-based synthetic leather prepared by this invention has a peel strength of 120-128 N / cm, a tear strength of 42.3-46.5 N / cm, a tensile strength of 507-512 N / cm, an abrasion resistance of 1 kg / 1007-1025 revolutions, and a bursting strength of 20.8-22.5 kg / cm. 2 The water permeability is 116-124 mg / 10cm. 2 24h;

[0057] The water-based synthetic leather prepared by this invention, when immersed in a 5% sodium chloride solution for 48 hours, exhibits a peel strength of 117-125 N / cm, a tear strength of 40.7-45.3 N / cm, a tensile strength of 489-503 N / cm, and a bursting strength of 20.0-21.8 kg / cm². 2 ;

[0058] The water-based synthetic leather prepared by this invention, after being left to stand at -25℃ for 10 days, exhibits a peel strength of 114-123 N / cm, a tear strength of 40.5-44.9 N / cm, a tensile strength of 487-497 N / cm, and a bursting strength of 19.7-21.6 kg / cm². 2 . Detailed Implementation

[0059] To provide a clearer understanding of the technical features, objectives, and effects of the present invention, specific embodiments of the present invention are now described.

[0060] Example 1

[0061] 1. Preparation of lavender essential oil

[0062] Dried lavender flowers were crushed to obtain lavender fragments. Then, 7 times the volume of deionized water was added, and the mixture was stirred evenly. The mixture was then subjected to ultrasonic treatment at a temperature of 32°C for 10 minutes. After ultrasonic treatment, the mixture was placed at 125°C for distillation for 2 hours. The distillate was salted out with sodium chloride solution and then allowed to stand at 4°C for 8 hours. After standing, the mixture was separated using a separatory funnel to obtain lavender essential oil.

[0063] The sodium chloride solution has a mass concentration of 4%.

[0064] 2. Preparation of microcapsules containing lavender essential oil A

[0065] (1) Preparation of wall material

[0066] Gelatin and maltodextrin were mixed, and then deionized water was added and stirred for 15 minutes at a speed of 127 rpm at a temperature of 42°C. After stirring, ethyl cellulose and sodium dodecyl sulfate were added and ultrasonically vibrated for 7 minutes at a frequency of 22 kHz. After the vibration treatment, the wall material solution was obtained.

[0067] The mass ratio of gelatin, maltodextrin, deionized water, ethyl cellulose, and sodium lauryl sulfate is 3.8:2.2:37:0.8:0.4.

[0068] (2) Preparation of core material

[0069] Lavender essential oil and soybean lecithin were mixed and stirred at 150 rpm for 23 minutes. The core material was obtained after stirring.

[0070] The mass ratio of lavender essential oil to soybean lecithin is 11:2.7;

[0071] (3) Mixing

[0072] The wall material and core material were mixed, and then ethylene bis-stearamide was added for homogenization. The homogenization was performed 3 times, the homogenization pressure was 3.5 MPa, and the homogenization time was 5 min each time. After the homogenization was completed, spray drying was performed. The inlet air temperature of the spray tower was controlled at 138℃ and the outlet air temperature was controlled at 70℃. After drying, the mixture was cooled to room temperature and passed through a 100-mesh sieve to obtain microcapsules A containing lavender essential oil.

[0073] The mass ratio of the wall material, core material and ethylene bis-stearamide is 11:1.2:0.3.

[0074] 3. Preparation of microcapsules containing lavender essential oil B

[0075] (1) Modified microcrystalline cellulose

[0076] Microcrystalline cellulose was placed in a sodium hydroxide solution of 3 times its volume and stirred for 5 minutes. After stirring, it was washed and dried to obtain alkali-impregnated microcrystalline cellulose. The alkali-impregnated microcrystalline cellulose was then impregnated in an impregnation solution of 4 times its volume at a temperature of 40°C for 25 minutes. Pressure was applied during impregnation, and the impregnation pressure was controlled at 0.7 MPa. After impregnation, the temperature was first lowered to 4.2°C at a rate of 1.0°C / min, and then pre-cooled and dried at a temperature of -13°C for 18 minutes. After pre-cooling, freeze-drying was performed at a temperature of -28°C for 24 minutes. After freeze-drying, the temperature was allowed to return to room temperature naturally to obtain modified microcrystalline cellulose.

[0077] The sodium hydroxide solution has a mass concentration of 14%.

[0078] The impregnation solution is a mixture of sodium hydroxypropyl cellulose, polyvinylpyrrolidone, and deionized water, wherein the mass ratio of sodium hydroxypropyl cellulose, polyvinylpyrrolidone, and deionized water is 4.5:3.2:37.

[0079] (2) Embedding

[0080] Modified microcrystalline cellulose was mixed with sodium alginate and gum arabic, and then deionized water was added and stirred for 17 minutes at a speed of 184 rpm and a temperature of 48°C. After stirring, a mixture was obtained. Lavender essential oil and cocamidopropyl betaine were added to the mixture, and the mixture was placed in a sealed container for sealing treatment for 32 minutes at a pressure of 0.5 MPa. After sealing treatment, the mixture was frozen at -36°C and then allowed to naturally return to room temperature to obtain microcapsules B containing lavender essential oil.

[0081] The mass ratio of the modified microcrystalline cellulose, sodium alginate, gum arabic, and deionized water is 12:8:14:110.

[0082] The mass ratio of the mixture, lavender essential oil and cocamidopropyl betaine is 76:8.5:1.3.

[0083] 4. Preparation of waterborne polyurethane emulsion

[0084] Polyethylene glycol was vacuum dehydrated at 120°C for 2 hours. The temperature was then lowered to 55°C, and diisocyanate and dibutyltin dilaurate were added for a reaction at 84°C for 1.4 hours. 1,3-propanediol, dimethylolpropionic acid, and trimethylolpropane were then added and the reaction continued for 2.5 hours. The temperature was then lowered to 54°C, and acetone was added as a viscosity reducer. The temperature was then lowered to 35°C, and triethylamine was added as a neutralizing agent. The reaction was carried out for 5 minutes, and the temperature was lowered to 26°C. Deionized water was added and the mixture was stirred for 24 minutes to obtain an aqueous polyurethane emulsion.

[0085] The mass ratio of polyethylene glycol, diisocyanate, dibutyltin dilaurate, 1,3-propanediol, dimethylolpropionic acid, trimethylolpropane, acetone, triethylamine, and deionized water is 110:29:0.25:2.4:4.7:0.28:90:4.3:347.

[0086] 5. Preparation of slurry

[0087] Waterborne polyurethane resin, microcapsules A containing lavender essential oil, dimethyl silicone oil, hydroxymethyl cellulose, sodium stearate, activated carbon black and deionized water were mixed and then ball-milled for 32 minutes at a speed of 780 rpm, with a ball-to-material ratio of 4:1 and a ball-milling temperature of 32°C. The bottom slurry was obtained after the ball milling was completed.

[0088] Waterborne polyurethane resin, microcapsules B containing lavender essential oil, dimethyl silicone oil, hydroxymethyl cellulose, sodium stearate, pigment, activated carbon black and deionized water were mixed and then ball-milled for 41 minutes at a speed of 820 rpm, with a ball-to-material ratio of 8:1 and a ball-milling temperature of 35°C. The surface slurry was obtained after the ball milling was completed.

[0089] In the preparation of the bottom slurry, the mass ratio of the waterborne polyurethane resin, microcapsules A containing lavender essential oil, dimethyl silicone oil, hydroxymethyl cellulose, sodium stearate, activated carbon black, and deionized water is 94:5.7:1.3:2.2:1.8:3.0:18.

[0090] In the preparation of the surface layer slurry, the mass ratio of the waterborne polyurethane resin, microcapsules B containing lavender essential oil, dimethyl silicone oil, hydroxymethyl cellulose, sodium stearate, pigment, activated carbon black, and deionized water is 110:6.0:1.5:2.6:2.0:5.0:4.3:23.

[0091] The method for preparing activated carbon black is as follows: precipitated silica is calcined at 120°C for 20 min, then heated to 180°C at a rate of 4°C / min, calcined at 180°C for 25 min, then heated to 250°C at a rate of 2°C / min, and calcined at 250°C for 32 min. After calcination, the silica is cooled to room temperature, deionized water, polyethylene glycol, and citric acid are added, and then plasma treatment is performed for 25 s, at a frequency of 12 kHz and a power of 32 W. After treatment, the silica is dried to obtain activated carbon black.

[0092] The mass ratio of carbon black, deionized water, polyethylene glycol, and citric acid is 12:57:2.3:3.0.

[0093] 6. Coating

[0094] The surface layer paste is coated under the release paper at a coating amount of 100g / m². 2 The top layer is obtained by drying at 110℃. A TPU adhesive is then applied underneath the top layer to form the adhesive layer. Finally, a base coat of slurry is applied underneath the adhesive layer at a coating weight of 100g / m². 2 The bottom layer is dried at 110℃. The non-woven fabric is preheated at 100℃ and then bonded to the bottom layer with a bonding pressure of 0.6MPa. After bonding, it is dried at 105℃ and finally cooled and peeled to obtain water-based synthetic leather.

[0095] Example 2

[0096] 1. Preparation of lavender essential oil

[0097] Dried lavender flowers were crushed to obtain lavender fragments. Then, 6 times the volume of deionized water was added, and the mixture was stirred evenly. The mixture was then subjected to ultrasonic treatment at a temperature of 30°C for 8 minutes. After ultrasonic treatment, the mixture was placed at 120°C for distillation for 1.7 hours. The distillate was salted out with sodium chloride solution and then allowed to stand at 3.6°C for 7.7 hours. After standing, the mixture was separated using a separatory funnel to obtain lavender essential oil.

[0098] The sodium chloride solution has a mass concentration of 3.8%.

[0099] 2. Preparation of microcapsules containing lavender essential oil A

[0100] (1) Preparation of wall material

[0101] Gelatin and maltodextrin were mixed, and then deionized water was added and stirred for 13 minutes at a speed of 120 rpm at a temperature of 40°C. After stirring, ethyl cellulose and sodium dodecyl sulfate were added and ultrasonically vibrated for 6 minutes at a frequency of 20 kHz. After the vibration treatment, the wall material solution was obtained.

[0102] The mass ratio of gelatin, maltodextrin, deionized water, ethyl cellulose, and sodium lauryl sulfate is 3.6:2.4:35:0.6:0.3.

[0103] (2) Preparation of core material

[0104] Lavender essential oil and soybean lecithin were mixed and stirred at 142 rpm for 20 minutes. The core material was obtained after stirring.

[0105] The mass ratio of lavender essential oil to soybean lecithin is 10:2.5;

[0106] (3) Mixing

[0107] The wall material and core material were mixed, and then ethylene bis-stearamide was added for homogenization. The homogenization was performed 3 times, the homogenization pressure was 3.2 MPa, and the homogenization time was 6 min each time. After the homogenization was completed, spray drying was performed. The inlet air temperature of the spray tower was controlled at 136℃ and the outlet air temperature was controlled at 68℃. After drying, the mixture was cooled to room temperature and passed through an 80-mesh sieve to obtain microcapsules A containing lavender essential oil.

[0108] The mass ratio of the wall material, core material and ethylene bis-stearamide is 10:1.0:0.2.

[0109] 3. Preparation of microcapsules containing lavender essential oil B

[0110] (1) Modified microcrystalline cellulose

[0111] Microcrystalline cellulose was placed in a sodium hydroxide solution of 2 times its volume and stirred for 4 minutes. After stirring, it was washed and dried to obtain alkali-impregnated microcrystalline cellulose. The alkali-impregnated microcrystalline cellulose was then impregnated in an impregnation solution of 3 times its volume at a temperature of 38°C for 22 minutes. Pressure was applied during impregnation, and the impregnation pressure was controlled at 0.6 MPa. After impregnation, the temperature was first lowered to 4.0°C at a rate of 0.8°C / min, and then pre-cooled and dried at a temperature of -15°C for 20 minutes. After pre-cooling, freeze-drying was performed at a temperature of -30°C for 20 minutes. After freeze-drying, the temperature was allowed to return to room temperature naturally to obtain modified microcrystalline cellulose.

[0112] The sodium hydroxide solution has a mass concentration of 13%.

[0113] The impregnation solution is a mixture of sodium hydroxypropyl cellulose, polyvinylpyrrolidone, and deionized water, wherein the mass ratio of sodium hydroxypropyl cellulose, polyvinylpyrrolidone, and deionized water is 4.4:3.0:35.

[0114] (2) Embedding

[0115] Modified microcrystalline cellulose was mixed with sodium alginate and gum arabic, and then deionized water was added and stirred for 15 minutes at a speed of 178 rpm and a temperature of 45°C. After stirring, a mixture was obtained. Lavender essential oil and cocamidopropyl betaine were added to the mixture, and the mixture was placed in a sealed container for sealing treatment for 30 minutes at a pressure of 0.4 MPa. After sealing treatment, the mixture was frozen at -38°C and then allowed to naturally return to room temperature to obtain microcapsules B containing lavender essential oil.

[0116] The mass ratio of the modified microcrystalline cellulose, sodium alginate, gum arabic, and deionized water is 11:7:15:106.

[0117] The mass ratio of the mixture, lavender essential oil and cocamidopropyl betaine is 73:8.2:1.1.

[0118] 4. Preparation of waterborne polyurethane emulsion

[0119] Polyethylene glycol was vacuum dehydrated at 117°C for 1.7 h. The temperature was then lowered to 53°C, and diisocyanate and dibutyltin dilaurate were added for a reaction at 82°C for 1.2 h. Then, 1,3-propanediol, dimethylolpropionic acid, and trimethylolpropane were added and the reaction continued for 2.2 h. The temperature was then lowered to 52°C, and acetone was added as a viscosity reducer. The temperature was then lowered to 32°C, and triethylamine was added as a neutralizing agent. The reaction was carried out for 4 min, and the temperature was lowered to 25°C, and deionized water was added. The mixture was stirred for 20 min to obtain an aqueous polyurethane emulsion.

[0120] The mass ratio of polyethylene glycol, diisocyanate, dibutyltin dilaurate, 1,3-propanediol, dimethylolpropionic acid, trimethylolpropane, acetone, triethylamine, and deionized water is 108:27:0.23:2.3:4.6:0.26:87:4.1:342.

[0121] 5. Preparation of slurry

[0122] Waterborne polyurethane resin, microcapsules A containing lavender essential oil, dimethyl silicone oil, hydroxymethyl cellulose, sodium stearate, activated carbon black and deionized water were mixed and then ball-milled for 30 minutes at a speed of 775 rpm, with a ball-to-material ratio of 2:1 and a ball-milling temperature of 30°C. The bottom slurry was obtained after the ball milling was completed.

[0123] Waterborne polyurethane resin, microcapsules B containing lavender essential oil, dimethyl silicone oil, hydroxymethyl cellulose, sodium stearate, pigment, activated carbon black and deionized water were mixed and then ball-milled for 38 minutes at a speed of 815 rpm, with a ball-to-material ratio of 6:1 and a ball-milling temperature of 32°C. The surface slurry was obtained after the ball milling was completed.

[0124] In the preparation of the bottom slurry, the mass ratio of the waterborne polyurethane resin, microcapsules A containing lavender essential oil, dimethyl silicone oil, hydroxymethyl cellulose, sodium stearate, activated carbon black and deionized water is 92:5.5:1.2:2.0:1.7:2.7:16.

[0125] In the preparation of the surface layer slurry, the mass ratio of the waterborne polyurethane resin, microcapsules B containing lavender essential oil, dimethyl silicone oil, hydroxymethyl cellulose, sodium stearate, pigment, activated carbon black and deionized water is 107:5.8:1.4:2.3:1.8:4.8:4.1:20.

[0126] The method for preparing activated carbon black is as follows: precipitated silica is calcined at 115°C for 22 min, then heated to 176°C at a rate of 3.8°C / min and calcined at 176°C for 30 min, then heated to 246°C at a rate of 1.8°C / min and calcined at 246°C for 30 min. After calcination, the silica is cooled to room temperature, deionized water, polyethylene glycol, and citric acid are added, and then plasma treatment is performed for 23 s, at a frequency of 10 kHz and a power of 30 W. After treatment, the silica is dried to obtain activated carbon black.

[0127] The mass ratio of carbon black, deionized water, polyethylene glycol, and citric acid is 10:53:2.1:2.8.

[0128] 6. Coating

[0129] The surface layer slurry is coated under the release paper at a coating amount of 95 g / m². 2 The top layer is prepared by drying at 107℃. A TPU adhesive is then applied beneath the top layer to form the adhesive layer. Finally, a base coat of 97 g / m² is applied beneath the adhesive layer. 2 The bottom layer is dried at 108℃. The non-woven fabric is preheated at 95℃ and then bonded to the bottom layer with a bonding pressure of 0.5MPa. After bonding, it is dried at 103℃. Finally, it is cooled and peeled off to obtain water-based synthetic leather.

[0130] Example 3

[0131] 1. Preparation of lavender essential oil

[0132] Dried lavender flowers were crushed to obtain lavender fragments. Then, 8 times the volume of deionized water was added, and the mixture was stirred evenly. The mixture was then subjected to ultrasonic treatment at a temperature of 34℃ for 12 minutes. After ultrasonic treatment, the mixture was placed at 130℃ for distillation for 2.2 hours. The distillate was salted out with sodium chloride solution and then allowed to stand at 4.5℃ for 8.2 hours. After standing, the mixture was separated using a separatory funnel to obtain lavender essential oil.

[0133] The sodium chloride solution has a mass concentration of 4.2%.

[0134] 2. Preparation of microcapsules containing lavender essential oil A

[0135] (1) Preparation of wall material

[0136] Gelatin and maltodextrin were mixed, and then deionized water was added and stirred for 17 minutes at a speed of 135 rpm at a temperature of 44°C. After stirring, ethyl cellulose and sodium dodecyl sulfate were added and ultrasonically vibrated for 8 minutes at a frequency of 25 kHz. After the vibration treatment, the wall material solution was obtained.

[0137] The mass ratio of gelatin, maltodextrin, deionized water, ethyl cellulose and sodium lauryl sulfate is 4.0:2.0:40:0.9:0.5.

[0138] (2) Preparation of core material

[0139] Lavender essential oil and soybean lecithin were mixed and stirred at 155 rpm for 25 minutes. The core material was obtained after stirring.

[0140] The mass ratio of lavender essential oil to soybean lecithin is 12:2.8;

[0141] (3) Mixing

[0142] The wall material and core material were mixed, and then ethylene bis-stearamide was added for homogenization. The homogenization was performed 3 times, the homogenization pressure was 3.7 MPa, and the homogenization time was 4 min each time. After the homogenization was completed, spray drying was performed. The inlet air temperature of the spray tower was controlled at 140℃ and the outlet air temperature was controlled at 72℃. After drying, the mixture was cooled to room temperature and passed through a 120-mesh sieve to obtain microcapsules A containing lavender essential oil.

[0143] The mass ratio of the wall material, core material and ethylene bis-stearamide is 13:1.3:0.5.

[0144] 3. Preparation of microcapsules containing lavender essential oil B

[0145] (1) Modified microcrystalline cellulose

[0146] Microcrystalline cellulose was placed in 4 times its volume of sodium hydroxide solution and stirred for 6 minutes. After stirring, it was washed and dried to obtain alkali-impregnated microcrystalline cellulose. The alkali-impregnated microcrystalline cellulose was then impregnated in 5 times its volume of impregnation solution at a temperature of 42°C for 28 minutes. Pressure was applied during impregnation, and the impregnation pressure was controlled at 0.8 MPa. After impregnation, the temperature was first lowered to 4.5°C at a rate of 1.2°C / min, and then pre-cooled and dried at a temperature of -11°C for 17 minutes. After pre-cooling, freeze-drying was performed at a temperature of -25°C for 30 minutes. After freeze-drying, the temperature was allowed to return to room temperature naturally to obtain modified microcrystalline cellulose.

[0147] The sodium hydroxide solution has a mass concentration of 15%.

[0148] The impregnation solution is a mixture of sodium hydroxypropyl cellulose, polyvinylpyrrolidone, and deionized water, wherein the mass ratio of sodium hydroxypropyl cellulose, polyvinylpyrrolidone, and deionized water is 4.7:3.3:40.

[0149] (2) Embedding

[0150] Modified microcrystalline cellulose was mixed with sodium alginate and gum arabic, and then deionized water was added and stirred for 20 minutes at a speed of 190 rpm and a temperature of 51°C. After stirring, a mixture was obtained. Lavender essential oil and cocamidopropyl betaine were added to the mixture, and the mixture was placed in a sealed container for sealing treatment for 36 minutes at a pressure of 0.6 MPa. After sealing treatment, the mixture was frozen at -35°C and then allowed to naturally return to room temperature to obtain microcapsules B containing lavender essential oil.

[0151] The mass ratio of the modified microcrystalline cellulose, sodium alginate, gum arabic, and deionized water is 13:9:13:115.

[0152] The mass ratio of the mixture, lavender essential oil and cocamidopropyl betaine is 80:8.8:1.5.

[0153] 4. Preparation of waterborne polyurethane emulsion

[0154] Polyethylene glycol was vacuum dehydrated at 122°C for 2.2 hours. The temperature was then lowered to 57°C, and diisocyanate and dibutyltin dilaurate were added for a reaction at 86°C for 1.6 hours. 1,3-propanediol, dimethylolpropionic acid, and trimethylolpropane were then added and the reaction continued for 2.7 hours. The temperature was then lowered to 56°C, and acetone was added as a viscosity reducer. The temperature was then lowered to 38°C, and triethylamine was added as a neutralizing agent. The reaction was carried out for 6 minutes, and the temperature was lowered to 27°C. Deionized water was added and the mixture was stirred for 32 minutes to obtain an aqueous polyurethane emulsion.

[0155] The mass ratio of polyethylene glycol, diisocyanate, dibutyltin dilaurate, 1,3-propanediol, dimethylolpropionic acid, trimethylolpropane, acetone, triethylamine, and deionized water is 112:31:0.27:2.5:4.8:0.30:93:4.5:350.

[0156] 5. Preparation of slurry

[0157] Waterborne polyurethane resin, microcapsules A containing lavender essential oil, dimethyl silicone oil, hydroxymethyl cellulose, sodium stearate, activated carbon black and deionized water were mixed and then ball-milled for 34 minutes at a speed of 785 rpm, with a ball-to-material ratio of 6:1 and a ball-milling temperature of 35°C. The bottom slurry was obtained after the ball milling was completed.

[0158] Waterborne polyurethane resin, microcapsules B containing lavender essential oil, dimethyl silicone oil, hydroxymethyl cellulose, sodium stearate, pigment, activated carbon black and deionized water were mixed and then ball-milled for 45 minutes at a speed of 823 rpm, with a ball-to-material ratio of 10:1 and a ball-milling temperature of 38°C. The surface slurry was obtained after the ball milling was completed.

[0159] In the preparation of the bottom slurry, the mass ratio of the waterborne polyurethane resin, microcapsules A containing lavender essential oil, dimethyl silicone oil, hydroxymethyl cellulose, sodium stearate, activated carbon black, and deionized water is 96:5.9:1.4:2.4:1.9:3.3:20.

[0160] In the preparation of the surface layer slurry, the mass ratio of the waterborne polyurethane resin, microcapsules B containing lavender essential oil, dimethyl silicone oil, hydroxymethyl cellulose, sodium stearate, pigment, activated carbon black, and deionized water is 113:6.2:1.6:2.9:2.2:5.2:4.5:25.

[0161] The method for preparing activated carbon black is as follows: precipitated silica is calcined at 125°C for 18 min, then heated to 184°C at a rate of 4.2°C / min and calcined at 184°C for 22 min, then heated to 254°C at a rate of 2.2°C / min and calcined at 254°C for 34 min. After calcination, the silica is cooled to room temperature, deionized water, polyethylene glycol, and citric acid are added, and then plasma treatment is performed for 27 s, at a frequency of 14 kHz and a power of 34 W. After treatment, the silica is dried to obtain activated carbon black.

[0162] The mass ratio of carbon black, deionized water, polyethylene glycol, and citric acid is 14:62:2.5:3.2.

[0163] 6. Coating

[0164] The surface layer paste is coated under the release paper at a coating amount of 105 g / m². 2 The top layer is prepared by drying at 114℃. A TPU adhesive is then applied beneath the top layer to form the adhesive layer. Finally, a base coat of slurry is applied beneath the adhesive layer at a coating weight of 103 g / m². 2 The bottom layer is dried at 112℃. The non-woven fabric is preheated at 105℃ and then bonded to the bottom layer with a bonding pressure of 0.7MPa. After bonding, it is dried at 107℃ and finally cooled and peeled to obtain water-based synthetic leather.

[0165] Comparative Example 1

[0166] Based on Example 1, the change is that the preparation of microcapsules A and B containing lavender essential oil is omitted. In the preparation of the bottom layer slurry and the top layer slurry, both microcapsules A and B containing lavender essential oil are directly replaced with lavender essential oil. All other operations are the same.

[0167] Comparative Example 2

[0168] Based on Example 1, the changes are as follows: in the step of preparing microcapsules B containing lavender essential oil, the modification step of microcrystalline cellulose is omitted, and untreated microcrystalline cellulose is used directly. In addition, during the encapsulation process, "freezing at -36°C" is replaced with "drying at 110°C". All other operations are the same.

[0169] Comparative Example 3

[0170] Based on Example 1, the changes are as follows: in the preparation of the bottom layer slurry and the top layer slurry, the ball milling process is replaced with the stirring process, and the activated carbon black is replaced with untreated carbon black.

[0171] The steps for preparing the slurry are as follows:

[0172] Waterborne polyurethane resin, microcapsules A containing lavender essential oil, dimethyl silicone oil, hydroxymethyl cellulose, sodium stearate and deionized water are mixed and then stirred for 32 minutes at a speed of 780 rpm and a temperature of 32°C. The bottom slurry is obtained after stirring.

[0173] Waterborne polyurethane resin, microcapsules B containing lavender essential oil, dimethyl silicone oil, hydroxymethyl cellulose, sodium stearate, color powder and deionized water are mixed and then stirred for 41 minutes at a stirring speed of 820 rpm and a stirring temperature of 35°C. The surface slurry is obtained after stirring is completed.

[0174] In the preparation of the bottom slurry, the mass ratio of the waterborne polyurethane resin, microcapsules A containing lavender essential oil, dimethyl silicone oil, hydroxymethyl cellulose, sodium stearate, and deionized water is 94:5.7:1.3:2.2:1.8:18.

[0175] In the preparation of the surface layer slurry, the mass ratio of the waterborne polyurethane resin, microcapsules B containing lavender essential oil, dimethyl silicone oil, hydroxymethyl cellulose, sodium stearate, pigment, and deionized water is 110:6.0:1.5:2.6:2.0:5.0:23.

[0176] All other operations are the same.

[0177] Test case

[0178] 1. Antibacterial properties

[0179] (1) The antibacterial properties of the products prepared in Examples 1-3 and Comparative Examples 1-3 were tested, and the specific results are as follows:

[0180]

[0181] (2) The products obtained in Examples 1-3 and Comparative Examples 1-3 were placed in an environment with a temperature of 26°C and a humidity of 45°C for 6 years and their antibacterial properties were tested again. The specific results are as follows:

[0182]

[0183] 2. Overall physical properties

[0184] The products obtained in Examples 1-3 and Comparative Examples 1-3 were subjected to strength performance testing, and the specific results are as follows:

[0185]

[0186] 3. Water resistance

[0187] The water-based synthetic leathers prepared in Examples 1-3 and Comparative Examples 1-3 were immersed in a 5% sodium chloride solution for 48 hours, and their physical properties were tested again, as follows:

[0188]

[0189] 4. Low-temperature resistance

[0190] The water-based synthetic leathers prepared in Examples 1-3 and Comparative Examples 1-3 were placed at -25°C for 10 days and their physical properties were tested again, as follows:

[0191]

[0192] The above experimental results show that the present invention uses a specific method to prepare microcapsules A containing lavender essential oil, which avoids the loss of lavender essential oil during post-processing; and uses a specific method to prepare microcapsules B containing lavender essential oil, which modifies microcrystalline cellulose, resulting in good curing effect and ensuring the stability of the microcapsules. The combination of the two microcapsules effectively ensures the sustained-release performance of the essential oil and avoids the impact of directly adding the essential oil on the strength performance of synthetic leather, while enhancing the antibacterial durability and fragrance emission performance. The addition of activated carbon black during the preparation of the slurry, combined with a specific ball milling process, enhances the tensile strength, peel strength, tear strength, and bursting strength of the synthetic leather, improves the structural stability of the synthetic leather, reduces the loss of strength performance at low temperatures and after hydrolysis, and ensures water permeability.

[0193] According to Comparative Example 1, when lavender essential oil is added directly, some of the active ingredients of lavender will be lost during the post-processing, resulting in poor antibacterial performance, short-lasting antibacterial performance, and insufficient fragrance. Moreover, the method of directly adding essential oil will affect the strength, water resistance, low-temperature resistance and water permeability of synthetic leather.

[0194] According to Comparative Example 2, the use of untreated cellulose directly results in small pores and low porosity, which affects the coating effect. Furthermore, high-temperature drying treatment affects the structural stability of the pores, thereby affecting the stability of the microcapsules, further reducing the antibacterial properties and fragrance emission of synthetic leather, shortening the antibacterial action time, and reducing the stability of synthetic leather.

[0195] According to Comparative Example 3, omitting ball milling and directly using untreated carbon black will affect the dispersion performance of the slurry, leading to the agglomeration of slurry components, which in turn affects the strength and stability of synthetic leather, and further results in high strength loss of synthetic leather after low temperature and water immersion treatment.

[0196] Unless otherwise stated, all percentages used in this invention are mass percentages.

[0197] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A biofunctional water-based synthetic leather that emits a long-lasting natural lavender scent, characterized in that, The method for preparing the synthetic leather includes the following steps: preparation of lavender essential oil, preparation of microcapsules A containing lavender essential oil, preparation of microcapsules B containing lavender essential oil, preparation of waterborne polyurethane emulsion, preparation of slurry, and coating. The preparation of microcapsules A containing lavender essential oil includes the steps of preparing wall material, preparing core material, and mixing. The preparation steps of the wall material are as follows: gelatin and maltodextrin are mixed, then deionized water is added and stirred for 13-17 minutes, at a speed of 120-135 rpm and a temperature of 40-44℃. After stirring, ethyl cellulose and sodium dodecyl sulfate are added and ultrasonically vibrated for 6-8 minutes at a frequency of 20-25 kHz. After the vibration treatment, the wall material solution is obtained. The core material preparation steps are as follows: lavender essential oil and soybean lecithin are mixed and then stirred at a speed of 142-155 rpm for 20-25 min. The core material is obtained after stirring is completed. The mixing step is as follows: the wall material and the core material are mixed, and then ethylene bis-stearamide is added for homogenization treatment. The homogenization is performed 3 times, the homogenization pressure is 3.2-3.7 MPa, and the homogenization time is 4-6 min each time. After the homogenization treatment is completed, spray drying is performed. The inlet air temperature of the spray tower is controlled at 136-140℃ and the outlet air temperature is 68-72℃. After drying, the mixture is cooled to room temperature and passed through an 80-120 mesh sieve to obtain microcapsules A containing lavender essential oil. The preparation of microcapsules B containing lavender essential oil includes modified microcrystalline cellulose and an encapsulation step. The modified microcrystalline cellulose steps are as follows: microcrystalline cellulose is placed in 2-4 times its volume of sodium hydroxide solution and stirred for 4-6 minutes. After stirring, it is washed and dried to obtain alkali-impregnated microcrystalline cellulose. The alkali-impregnated microcrystalline cellulose is then impregnated in 3-5 times its volume of impregnation solution at a temperature of 38-42°C for 22-28 minutes. Pressure is applied during impregnation, and the impregnation pressure is controlled at 0.6-0.8 MPa. After impregnation, the temperature is first lowered to 4.0-4.5°C at a rate of 0.8-1.2°C / min, and then pre-cooled and dried at a temperature of -15 to -11°C for 17-20 minutes. After pre-cooling, freeze-drying is performed at a temperature of -30 to -25°C for 20-30 minutes. After freeze-drying, the mixture is allowed to return to room temperature naturally to obtain modified microcrystalline cellulose. The encapsulation step involves mixing modified microcrystalline cellulose with sodium alginate and gum arabic, then adding deionized water and stirring for 15-20 minutes at a speed of 178-190 rpm and a temperature of 45-51°C. After stirring, a mixture is obtained. Lavender essential oil and cocamidopropyl betaine are added to the mixture, and the mixture is placed in a sealed container for sealing treatment for 30-36 minutes at a pressure of 0.4-0.6 MPa. After sealing treatment, the mixture is placed at a temperature of -38 to -35°C for freezing treatment and then naturally restored to room temperature to obtain microcapsules B containing lavender essential oil. The preparation of the slurry involves mixing waterborne polyurethane resin, microcapsules A containing lavender essential oil, dimethyl silicone oil, hydroxymethyl cellulose, sodium stearate, activated carbon black, and deionized water, followed by ball milling. The ball milling time is 30-34 minutes, the ball milling speed is 775-785 rpm, the ball-to-material ratio is 2-6:1, and the ball milling temperature is 30-35℃. After ball milling, the bottom layer slurry is obtained. Waterborne polyurethane resin, microcapsules B containing lavender essential oil, dimethyl silicone oil, hydroxymethyl cellulose, sodium stearate, pigment, activated carbon black and deionized water are mixed and then ball-milled for 38-45 minutes at a speed of 815-823 rpm, with a ball-to-material ratio of 6-10:1 and a temperature of 32-38℃. The surface slurry is obtained after ball milling. The method for preparing activated carbon black is as follows: carbon black is calcined at 115-125℃ for 18-22 min, then heated to 176-184℃ at a rate of 3.8-4.2℃ / min and calcined at 176-184℃ for 22-30 min, then heated to 246-254℃ at a rate of 1.8-2.2℃ / min and calcined at 246-254℃ for 30-34 min. After calcination, the mixture is cooled to room temperature, and deionized water, polyethylene glycol, and citric acid are added. Then, plasma treatment is performed for 23-27 s, at a frequency of 10-14 kHz, and with a power of 30-34 W. After treatment, the mixture is dried to obtain activated carbon black.

2. The biofunctional water-based synthetic leather with a long-lasting natural lavender scent according to claim 1, characterized in that, In step A of preparing microcapsules containing lavender essential oil, the mass ratio of gelatin, maltodextrin, deionized water, ethyl cellulose and sodium lauryl sulfate is 3.6-4.0:2.0-2.4:35-40:0.6-0.9:0.3-0.

5. The mass ratio of lavender essential oil to soybean lecithin is 10-12:2.5-2.8; The mass ratio of the wall material, core material and ethylene bis-stearamide is 10-13:1.0-1.3:0.2-0.

5.

3. The biofunctional water-based synthetic leather with a long-lasting natural lavender scent according to claim 1, characterized in that, In the modified microcrystalline cellulose step, the mass concentration of the sodium hydroxide solution is 13-15%. The impregnation solution is a mixture of sodium hydroxypropyl cellulose, polyvinylpyrrolidone, and deionized water, wherein the mass ratio of sodium hydroxypropyl cellulose, polyvinylpyrrolidone, and deionized water is 4.4-4.7:3.0-3.3:35-40.

4. The biofunctional water-based synthetic leather with a long-lasting natural lavender scent according to claim 1, characterized in that, In the encapsulation step, the mass ratio of the modified microcrystalline cellulose, sodium alginate, gum arabic, and deionized water is 11-13:7-9:13-15:106-115. The mass ratio of the mixture, lavender essential oil and cocamidopropyl betaine is 73-80:8.2-8.8:1.1-1.

5.

5. The biofunctional water-based synthetic leather with a long-lasting natural lavender scent according to claim 1, characterized in that, In the activated carbon black step, the mass ratio of carbon black, deionized water, polyethylene glycol, and citric acid is 10-14:53-62:2.1-2.5:2.8-3.

2.

6. The biofunctional water-based synthetic leather with a long-lasting natural lavender scent according to claim 1, characterized in that, In the step of preparing the slurry, the mass ratio of the waterborne polyurethane resin, microcapsules A containing lavender essential oil, dimethyl silicone oil, hydroxymethyl cellulose, sodium stearate, activated carbon black, and deionized water in the preparation of the bottom layer slurry is 92-96:5.5-5.9:1.2-1.4:2.0-2.4:1.7-1.9:2.7-3.3:16-20; In the preparation of the surface layer slurry, the mass ratio of the waterborne polyurethane resin, microcapsules B containing lavender essential oil, dimethyl silicone oil, hydroxymethyl cellulose, sodium stearate, pigment, activated carbon black, and deionized water is 107-113:5.8-6.2:1.4-1.6:2.3-2.9:1.8-2.2:4.8-5.2:4.1-4.5:20-25.

7. The biofunctional water-based synthetic leather with a long-lasting natural lavender scent according to claim 1, characterized in that, The steps for preparing the waterborne polyurethane emulsion are as follows: polyethylene glycol is subjected to vacuum dehydration at 117-122℃ for 1.7-2.2 hours, the temperature is lowered to 53-57℃, diisocyanate and dibutyltin dilaurate are added for reaction for 1.2-1.6 hours at 82-86℃, then 1,3-propanediol, dimethylolpropionic acid and trimethylolpropane are added and the reaction continues for 2.2-2.7 hours, the temperature is lowered to 52-56℃, acetone is added as a viscosity reducer, the temperature is lowered to 32-38℃, triethylamine is added as a neutralizing agent and the neutralization reaction is carried out for 4-6 minutes, the temperature is lowered to 25-27℃, deionized water is added and the mixture is stirred for 20-32 minutes to obtain the waterborne polyurethane emulsion. The mass ratio of polyethylene glycol, diisocyanate, dibutyltin dilaurate, 1,3-propanediol, dimethylolpropionic acid, trimethylolpropane, acetone, triethylamine, and deionized water is 108-112:27-31:0.23-0.27:2.3-2.5:4.6-4.8:0.26-0.30:87-93:4.1-4.5:342-350.

8. The biofunctional water-based synthetic leather with a long-lasting natural lavender scent according to claim 1, characterized in that, The preparation steps of the lavender essential oil are as follows: crush dried lavender flowers to obtain lavender fragments, then add 6-8 times the volume of deionized water, mix evenly, and then perform ultrasonic treatment. The ultrasonic treatment temperature is controlled at 30-34℃, and the treatment time is 8-12 minutes. After ultrasonic treatment, the mixture is placed at 120-130℃ for distillation for 1.7-2.2 hours. The distillate is salted out with sodium chloride solution, and then allowed to stand at a low temperature of 3.6-4.5℃ for 7.7-8.2 hours. After standing, the mixture is separated using a separatory funnel to obtain lavender essential oil. The sodium chloride solution has a mass concentration of 3.8-4.2%.

9. The biofunctional waterborne synthetic leather with a long-lasting natural lavender scent according to claim 1, characterized in that... The coating step involves applying a surface layer slurry to the underside of the release paper, with a coating amount of 95-105 g / m². 2 The top layer is obtained by drying at 107-114℃. A TPU adhesive is then applied below the top layer to form the adhesive layer. Finally, a base coat of 97-103 g / m² is applied below the adhesive layer. 2 The bottom layer is dried at 108-112℃. The non-woven fabric is preheated at 95-105℃ and then bonded to the bottom layer with a bonding pressure of 0.5-0.7MPa. After bonding, it is dried at 103-107℃. Finally, it is cooled and peeled off to obtain water-based synthetic leather.

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