A fragrance microcapsule for long-lasting fragrance of a detergent and a preparation method thereof

Abstract

The present application relates to the field of essence technology, and particularly relates to an essence microcapsule for long-acting fragrance of detergent and a preparation method thereof, which comprises the following raw materials in percentage by weight: 10-40% of oily essence, 2-5% of emulsifier, 2-4.5% of prepolymer, 0.3-0.5% of stabilizer, 3-6% of formaldehyde capturing agent and 44-84% of deionized water. The essence microcapsule of the present application is prepared by in-situ polymerization of methyl etherified melamine resin prepolymer as wall material and oily essence as core, and the volatile essence is wrapped to protect the pure and long-lasting fragrance of the essence, and the preservation and stability of the essence microcapsule are improved. Compared with the common melamine resin microcapsule, the addition of the prepolymer, the stabilizer and the formaldehyde capturing agent makes the free formaldehyde residual content of the final product extremely low, the product emulsion is stable and not stratified, the product is stable and does not react with the detergent ingredients, and the product can be stably dispersed in the detergent matrix.

Description

Technical Field

[0001] This invention relates to the field of fragrance technology, specifically to a fragrance microcapsule for long-lasting fragrance retention in detergents and its preparation method. Background Technology

[0002] In recent years, the international laundry market has undergone tremendous changes. Compared to traditional laundry soaps and powders, liquid laundry detergents offer advantages such as rapid dissolution, strong cleaning power, and less skin irritation, making them more suitable for the laundry needs of modern families. With the development of the liquid laundry detergent market, the consumer market has become more segmented. As people become more familiar with liquid laundry detergents, their perception of fragrance has become clearer, and their demands for specific scents are increasing.

[0003] The main functions of fragrances can be summarized as: auxiliary function, aroma-enhancing function, flavor-correcting function, and decorative function. The aroma of pure fragrances is often easily affected by external factors due to the limitations of their components, thus impacting the product's essence. Improving the stability, slow-release properties, heat resistance, and longevity of fragrances has become crucial in determining the longevity of detergent fragrances. To give laundry products a pleasant aroma, fragrances and essential oils are added to the formulations of many laundry products, such as laundry detergents, fabric softeners, fragrance beads, and laundry gel pods. However, these aromatic compounds are often volatile and easily oxidized, and are also affected by the product's matrix. Summary of the Invention

[0004] To overcome the shortcomings and deficiencies of existing technologies, the present invention aims to provide a fragrance microcapsule for long-lasting fragrance retention in detergents. This fragrance microcapsule uses a methyl etherified melamine resin prepolymer as the wall material and an oily fragrance as the core, encapsulating the oily fragrance using an in-situ polymerization method. Encapsulating highly volatile fragrances protects the fragrance's purity and longevity, improving its preservation and stability. Furthermore, it alters the physical state of the fragrance, increasing its usability. Compared to ordinary melamine resin microcapsules, the addition of the prepolymer and formaldehyde scavenger results in extremely low free formaldehyde residue in the final product's fragrance microcapsules. The product emulsion is stable and does not separate, exhibiting stable properties and not reacting with detergent components. It can be stably dispersed in the detergent matrix without sedimentation, allowing for long-term storage and consistent product quality.

[0005] Another objective of this invention is to provide a method for preparing fragrance microcapsules for long-lasting fragrance in detergents. This preparation method is simple, easy to operate and control, produces high-quality products at low cost, and is suitable for industrial production. The preparation method involves mixing and emulsifying an oil-soluble fragrance with an anionic polymeric emulsifier to form an emulsion. Under acidic conditions, the emulsion is adsorbed and encapsulated with a methyl etherified melamine resin prepolymer. Under heating conditions, the emulsion undergoes a condensation reaction, crosslinking to form a polymer that coats the surface of the oil-soluble fragrance, thereby obtaining fragrance microcapsules. The obtained fragrance microcapsules can be combined with detergents such as laundry detergent, fabric softener, and fragrance beads. After washing, they are deposited on the surface of clothing, towels, and other fabrics, slowly releasing fragrance or breaking upon compression to release fragrance, thus prolonging the fragrance retention effect and increasing the multi-functionality of the detergent.

[0006] The objective of this invention is achieved through the following technical solution: a fragrance microcapsule for long-lasting fragrance in detergents, comprising the following raw materials by weight percentage: 10-40% oily fragrance, 2-5% emulsifier, 2-4.5% prepolymer, 0.3-0.5% stabilizer, 3-6% formaldehyde scavenger, and 44-84% deionized water.

[0007] More preferably, the raw materials include the following weight percentages: 10-35% oily fragrance, 8-12% emulsifier, 2-4.5% prepolymer, 0.3-0.5% stabilizer, 3-6% formaldehyde scavenger, and 44-84% deionized water.

[0008] The fragrance microcapsules of this invention use methyl etherified melamine resin prepolymer as the wall material and oily fragrance as the core. The oily fragrance is encapsulated using an in-situ polymerization method to obtain the fragrance capsules. Encapsulating highly volatile fragrances protects the purity and longevity of the aroma, improving the preservation and stability of the fragrance. Furthermore, it alters the physical state of the fragrance, increasing its usability. Compared to ordinary melamine resin microcapsules, the addition of prepolymer, stabilizer, and formaldehyde scavenger results in extremely low free formaldehyde residue in the final product. The product emulsion is stable and does not separate, exhibits stable properties and does not react with detergent components, can be stably dispersed in detergent matrices without sedimentation, can be stored for a long time, and maintains stable product quality.

[0009] Preferably, the oily fragrance is one or more of the following: green apple fragrance, lavender fragrance, floral fragrance, woody fragrance, and herbal fragrance.

[0010] Preferably, the emulsifier is one or more of styrene-maleic anhydride copolymer 520, sodium polystyrene sulfonate, ethylene-maleic anhydride copolymer, and acylglycinate.

[0011] Preferably, the prepolymer is a methyl etherified melamine resin prepolymer.

[0012] Preferably, the formaldehyde scavenging agent is one or more of urea, cyclohexylurea, and polyvinyl alcohol.

[0013] This invention also provides a method for preparing fragrance microcapsules for long-lasting fragrance in detergents, which is obtained through the following steps:

[0014] S1. According to the weight ratio, add the emulsifier to the reaction device, then add 86-90% of the total weight of deionized water, stir for 10-20 minutes to make it completely mixed, then add the oily fragrance to the mixed solution, and use a shearing machine to shear at 2500-8000 rap for 5-20 minutes to obtain the emulsion for later use.

[0015] S2. According to the weight ratio, add the prepolymer to the reaction device, add the remaining deionized water, stir to form a homogeneous solution, adjust the pH value of the emulsion obtained in step S1 to 3-5, and then slowly add the homogeneous solution to the emulsion and stir evenly to obtain a mixed solution for later use.

[0016] S3. Place the mixture obtained in step S2 in a constant temperature stirrer, slowly heat it to 80-85℃ and keep it at that temperature for 0.8-1.2h, add formaldehyde scavenger and stabilizer, and keep it at that temperature for 1-3h to obtain fragrance microcapsules.

[0017] The method for preparing fragrance microcapsules in this invention is simple, easy to operate and control, produces high-quality products at low cost, and is suitable for industrial production. The preparation method involves mixing and emulsifying an oil-soluble fragrance with an anionic polymeric emulsifier to form an emulsion. Under acidic conditions, this emulsion is adsorbed and encapsulated with a methyl etherified melamine resin prepolymer. Under heating, a condensation reaction occurs, cross-linking to form a polymer that coats the surface of the oil-soluble fragrance, thus obtaining fragrance microcapsules. These microcapsules can be combined with detergents such as laundry detergent, fabric softener, and fragrance beads. After washing, they deposit on the surface of clothing, towels, and other fabrics, slowly releasing fragrance or breaking upon compression to release fragrance, thus prolonging the fragrance's lasting effect and increasing the detergent's versatility. This reaction mechanism is more complex and safer than that of conventional in-situ polymerization microcapsules because the reaction process is affected not only by temperature, pH, stirring rate, shear rate, and reaction time, but also by the control of formaldehyde residue in the fragrance microcapsules. The reaction principle is as follows: First, the oil-soluble fragrance is mixed evenly with the anionic emulsifier solution and sheared to a uniform emulsion state. The emulsion is adjusted to acidity, and the prepolymer is slowly added. After mixing evenly, the mixture is heated and stirred to solidify. A formaldehyde scavenger is added during the reaction, and finally a stabilizer is added to obtain fragrance microcapsules.

[0018] Preferably, in step S3, the stirring speed in the thermostatic stirrer is 300-1000 rap.

[0019] Preferably, in step S2, one or more of the following are used to adjust the pH value: 30% hydrochloric acid solution, 30% citric acid solution, and 50% acetic acid solution.

[0020] The beneficial effects of this invention are as follows: The fragrance microcapsules of this invention use methyl etherified melamine resin prepolymer as the wall material and oily fragrance as the core. The oily fragrance is encapsulated using an in-situ polymerization method to obtain the fragrance capsules. Encapsulating highly volatile fragrances and flavors protects the purity and longevity of the fragrance aroma, improving its preservation and stability. Furthermore, it alters the physical state of the fragrance, increasing its usability. Compared to ordinary melamine resin microcapsules, the addition of prepolymer, stabilizer, and formaldehyde scavenger results in extremely low free formaldehyde residue in the final product. The product emulsion is stable and does not separate, exhibits stable properties and does not react with detergent components, can be stably dispersed in detergent matrices without sedimentation, can be stored for a long time, and maintains stable product quality. Attached Figure Description

[0021] Figure 1 This is a 40x optical microscope image of the flavor microcapsules prepared in Example 6;

[0022] Figure 2 This is a 100x optical microscope image of the flavor microcapsules prepared in Example 6;

[0023] Figure 3 This is the TGA curve of the flavor microcapsule prepared in Example 6. Detailed Implementation

[0024] To facilitate understanding by those skilled in the art, the following description is provided in conjunction with embodiments and appendices. Figure 1-3 The present invention will be further described below, and the content mentioned in the embodiments is not intended to limit the present invention.

[0025] Example 1

[0026] A fragrance microcapsule for long-lasting fragrance in detergents comprises the following raw materials in weight percentages: 30% oily fragrance, 5% emulsifier, 0.3% stabilizer, 4% prepolymer, 5% formaldehyde scavenger, and 55.7% deionized water.

[0027] The oily flavoring is green apple flavoring.

[0028] The emulsifier is styrene-maleic anhydride copolymer 520.

[0029] The prepolymer is a methyl etherified melamine resin prepolymer.

[0030] The formaldehyde scavenging agent is urea.

[0031] The stabilizer is a cationic acrylamide copolymer.

[0032] The fragrance microcapsules for long-lasting fragrance in detergents are prepared by the following steps:

[0033] S1. According to the weight ratio, add the emulsifier to the reaction device, then add 86% of the total weight of deionized water, stir for 10 minutes to make it completely mixed, then add the oily fragrance to the mixed solution, and use a shearing machine to shear at 3500 rap for 10 minutes to obtain the emulsion for later use.

[0034] S2. According to the weight ratio, add the prepolymer to the reaction device, add the remaining deionized water, stir to form a uniform solution, adjust the pH value of the emulsion obtained in step S1 to 3, and then slowly add the uniform solution to the emulsion and stir evenly to obtain a mixture for later use.

[0035] S3. Place the mixture obtained in step S2 in a constant temperature stirrer, slowly heat it to 80°C and keep it at that temperature for 1 hour, add formaldehyde scavenger and stabilizer, and keep it at that temperature for 2 hours to obtain fragrance microcapsules.

[0036] In step S3, the stirring speed in the thermostatic stirrer is 300 rap.

[0037] In step S2, a 30% hydrochloric acid solution is used to adjust the pH value.

[0038] Example 2

[0039] A fragrance microcapsule for long-lasting fragrance in detergents comprises the following raw materials in weight percentages: 25% oily fragrance, 4.5% emulsifier, 0.4% stabilizer, 3.8% prepolymer, 4% formaldehyde scavenger, and 62.3% deionized water.

[0040] The oily fragrance is lavender fragrance.

[0041] The emulsifier is sodium polystyrene sulfonate.

[0042] The prepolymer is a methyl etherified melamine resin prepolymer.

[0043] The formaldehyde scavenging agent is cyclohexylurea.

[0044] The stabilizer is a cationic acrylamide copolymer.

[0045] The fragrance microcapsules for long-lasting fragrance in detergents are prepared by the following steps:

[0046] S1. According to the weight ratio, add the emulsifier to the reaction device, then add 87% of the total weight of deionized water, stir for 13 minutes to make it completely mixed, then add the oily fragrance to the mixed solution, and shear it at 3000 rap for 8 minutes to obtain the emulsion for later use.

[0047] S2. According to the weight ratio, add the prepolymer to the reaction device, add the remaining deionized water, stir to form a homogeneous solution, adjust the pH value of the emulsion obtained in step S1 to 3.5, and then slowly add the homogeneous solution to the emulsion and stir evenly to obtain a mixture for later use.

[0048] S3. Place the mixture obtained in step S2 in a constant temperature stirrer, slowly heat it to 81°C and keep it at that temperature for 1 hour, add formaldehyde scavenger and stabilizer, and keep it at that temperature for 2 hours to obtain fragrance microcapsules.

[0049] In step S3, the stirring speed in the thermostatic stirrer is 450 rap.

[0050] In step S2, a 50% acetic acid solution is used to adjust the pH value.

[0051] Example 3

[0052] A fragrance microcapsule for long-lasting fragrance in detergents comprises the following raw materials in weight percentages: 20% oily fragrance, 3% emulsifier, 0.4% stabilizer, 3.5% prepolymer, 4% formaldehyde scavenger, and 69.1% deionized water.

[0053] The oily fragrance is a floral fragrance.

[0054] The emulsifier is an ethylene-maleic anhydride copolymer.

[0055] The prepolymer is a methyl etherified melamine resin prepolymer.

[0056] The formaldehyde scavenging agent is polyvinyl alcohol.

[0057] The stabilizer is a cationic acrylamide copolymer.

[0058] The fragrance microcapsules for long-lasting fragrance in detergents are prepared by the following steps:

[0059] S1. According to the weight ratio, add the emulsifier to the reaction device, then add 88% of the total weight of deionized water, stir for 15 minutes to make it completely mixed, then add the oily fragrance to the mixed solution, and use a shearing machine to shear at 2500 rap for 15 minutes to obtain the emulsion for later use.

[0060] S2. According to the weight ratio, add the prepolymer to the reaction device, add the remaining deionized water, stir to form a homogeneous solution, adjust the pH of the emulsion obtained in step S1 to 3.6, and then slowly add the homogeneous solution to the emulsion and stir evenly to obtain a mixture for later use.

[0061] S3. Place the mixture obtained in step S2 in a constant temperature stirrer, slowly heat it to 82℃ and keep it at that temperature for 1.0 h, add formaldehyde scavenger and stabilizer, and keep it at that temperature for 2 h to obtain fragrance microcapsules.

[0062] In step S3, the stirring speed in the thermostatic stirrer is 600 rap.

[0063] In step S2, a 30% citric acid solution is used to adjust the pH value.

[0064] Example 4

[0065] A fragrance microcapsule for long-lasting fragrance in detergents comprises the following raw materials in weight percentages: 40% oily fragrance, 5% emulsifier, 0.5% stabilizer, 4.5% prepolymer, 6% formaldehyde scavenger, and 56% deionized water.

[0066] The oily fragrance is a herbal fragrance.

[0067] The emulsifier is an acylglycine salt.

[0068] The prepolymer is a methyl etherified melamine resin prepolymer.

[0069] The formaldehyde scavenging agent is polyvinyl alcohol.

[0070] The stabilizer is a cationic acrylamide copolymer.

[0071] The fragrance microcapsules for long-lasting fragrance in detergents are prepared by the following steps:

[0072] S1. According to the weight ratio, add the emulsifier to the reaction device, then add 89% of the total weight of deionized water, stir for 18 minutes to make it completely mixed, then add the oily fragrance to the mixed solution, and use a shearing machine to shear at 8000 rap for 10 minutes to obtain the emulsion for later use.

[0073] S2. According to the weight ratio, add the prepolymer to the reaction device, add the remaining deionized water, stir to form a homogeneous solution, adjust the pH of the emulsion obtained in step S1 to 4.0, and then slowly add the homogeneous solution to the emulsion and stir evenly to obtain a mixture for later use.

[0074] S3. Place the mixture obtained in step S2 in a constant temperature stirrer, slowly heat it to 84℃ and keep it at that temperature for 1 hour, add formaldehyde scavenger and stabilizer, and keep it at that temperature for 2 hours to obtain fragrance microcapsules.

[0075] In step S3, the stirring speed in the thermostatic stirrer is 850 rap.

[0076] In step S2, a 30% hydrochloric acid solution is used to adjust the pH value.

[0077] Example 5

[0078] A fragrance microcapsule for long-lasting fragrance in detergents comprises the following raw materials in weight percentages: 10% oily fragrance, 2% emulsifier, 0.5% stabilizer, 2% prepolymer, 6% formaldehyde scavenger, and 79.5% deionized water.

[0079] The oily flavoring is green apple flavoring.

[0080] The emulsifier is styrene-maleic anhydride copolymer 520.

[0081] The prepolymer is a methyl etherified melamine resin prepolymer.

[0082] The formaldehyde scavenging agent is cyclohexylurea.

[0083] The stabilizer is a cationic acrylamide copolymer.

[0084] The fragrance microcapsules for long-lasting fragrance in detergents are prepared by the following steps:

[0085] S1. According to the weight ratio, add the emulsifier to the reaction device, then add 90% of the total weight of deionized water, stir for 20 minutes to make it completely mixed, then add the oily fragrance to the mixed solution, and shear it at 3000 rap for 5 minutes to obtain the emulsion for later use.

[0086] S2. According to the weight ratio, add the prepolymer to the reaction device, add the remaining deionized water, stir to form a uniform solution, adjust the pH value of the emulsion obtained in step S1 to 5, and then slowly add the uniform solution to the emulsion and stir evenly to obtain a mixture for later use.

[0087] S3. Place the mixture obtained in step S2 in a constant temperature stirrer, slowly heat it to 85°C and keep it at that temperature for 1 hour, add formaldehyde scavenger and stabilizer, and keep it at that temperature for 2 hours to obtain fragrance microcapsules.

[0088] In step S3, the stirring speed in the thermostatic stirrer is 1000 rap.

[0089] In step S2, a 30% hydrochloric acid solution is used to adjust the pH value.

[0090] Example 6

[0091] A fragrance microcapsule for long-lasting fragrance in detergents comprises the following raw materials by weight percentage: 30g of oily fragrance, 5g of emulsifier, 0.3g of stabilizer, 4g of prepolymer, 5g of formaldehyde scavenger, and 55.7g of deionized water.

[0092] The oily flavoring is green apple flavoring.

[0093] The emulsifier is styrene-maleic anhydride copolymer 520.

[0094] The prepolymer is a methyl etherified melamine resin prepolymer.

[0095] The formaldehyde scavenging agent is cyclohexylurea.

[0096] The stabilizer is a cationic acrylamide copolymer.

[0097] The fragrance microcapsules for long-lasting fragrance in detergents are prepared by the following steps:

[0098] S1. According to the weight ratio, add the emulsifier to the reaction device, then add 86% of the total weight of deionized water, stir for 15 minutes to make it completely mixed, then add the oily fragrance to the mixed solution, and use a shearing machine to shear at 3000 rap for 10 minutes to obtain the emulsion for later use.

[0099] S2. According to the weight ratio, add the prepolymer to the reaction device, add the remaining deionized water, stir to form a uniform solution, adjust the pH value of the emulsion obtained in step S1 to 5, and then slowly add the uniform solution to the emulsion and stir evenly to obtain a mixture for later use.

[0100] S3. Place the mixture obtained in step S2 in a constant temperature stirrer, slowly heat it to 80°C and keep it at that temperature for 1 hour, add formaldehyde scavenging agent, and keep it at that temperature for 2 hours to obtain fragrance microcapsules.

[0101] In step S3, the stirring speed in the thermostatic stirrer is 350 rap.

[0102] In step S2, a 30% hydrochloric acid solution is used to adjust the pH value.

[0103] Add the fragrance microcapsules prepared in Example 6 to the detergent matrix, add 30g of fragranced laundry detergent to a 5L washing machine, wash for 45 minutes as normal, then remove and spin dry.

[0104] Then add green apple fragrance to the detergent base, and add 30g of scented laundry detergent to a 5L washing machine. After washing for 45 minutes as normal, take it out, spin dry, and air dry.

[0105] Take a 5L washing machine, wash for 45 minutes as usual, then remove and spin dry, serving as a blank control. After drying the clothes, compare the fragrance of the clothes and evaluate their aroma. See Table 1 for details, and Table 2 for the stability comparison of the fragrance microcapsule emulsion.

[0106] The above-mentioned fragrance microcapsules are used in amounts of 0.1% to 0.36%, and the amount of fragrance used is 80% of the amount used in the fragrance microcapsules.

[0107] Table 1

[0108]

[0109] As shown in the table above, the fragrance microcapsules prepared in this application are deposited on the surface of clothing, towels and other fabrics after washing, and slowly release fragrance or break and release fragrance after being squeezed, thus prolonging the fragrance retention effect and increasing the multi-effect of detergent.

[0110] Table 2

[0111]

[0112]

[0113] As shown in the table above, the emulsion formed by the fragrance microcapsules prepared in this application does not separate into layers when stored for a long time at room temperature and 50°C, and has excellent stability.

[0114] The above embodiments are preferred implementations of the present invention. In addition, the present invention can be implemented in other ways. Any obvious substitutions without departing from the concept of the present invention are within the protection scope of the present invention.

Claims

1. A fragrance microcapsule for long-lasting fragrance retention in detergents, characterized in that: The raw materials comprise the following weight percentages: 10-40% oily fragrance, 2-5% emulsifier, 2-4.5% prepolymer, 0.3-0.5% stabilizer, 3-6% formaldehyde scavenger, and 44-79.5% deionized water; wherein the prepolymer is a methyl etherified melamine resin prepolymer; the stabilizer is a cationic acrylamide copolymer; and the formaldehyde scavenger is one or more of urea, cyclohexylurea, and polyvinyl alcohol. The method for preparing the fragrance microcapsules for long-lasting fragrance in detergents involves the following steps: S1. According to the weight ratio, add the emulsifier to the reaction device, then add 86-90% of the total weight of deionized water, stir for 10-20 minutes to make it completely mixed, then add the oily fragrance to the mixed solution, and use a shearing machine to shear at 2500-8000 rpm for 5-20 minutes to obtain the emulsion for later use. S2. According to the weight ratio, add the prepolymer to the reaction device, add the remaining deionized water, stir to form a uniform solution, adjust the pH value of the emulsion obtained in step S1 to 3-5, and then slowly add the uniform solution to the emulsion and stir evenly to obtain a mixture for later use. S3. Place the mixture obtained in step S2 in a constant temperature stirrer, slowly heat it to 80-85℃ and keep it at that temperature for 0.8-1.2h, add formaldehyde scavenger and stabilizer, and keep it at that temperature for another 1-3h to obtain fragrance microcapsules.

2. The fragrance microcapsule for long-lasting fragrance in detergents according to claim 1, characterized in that: The oily fragrance is one or more of the following: green apple fragrance, lavender fragrance, floral fragrance, woody fragrance, and herbal fragrance.

3. The fragrance microcapsule for long-lasting fragrance in detergents according to claim 1, characterized in that: The emulsifier is one or more of the following: styrene-maleic anhydride copolymer 520, sodium polystyrene sulfonate, ethylene-maleic anhydride copolymer, and acylglycinate.

4. The fragrance microcapsule for long-lasting fragrance in detergents according to claim 1, characterized in that: In step S3, the stirring speed in the thermostatic stirrer is 300-1000 rpm.

5. A fragrance microcapsule for long-lasting fragrance in detergents according to claim 1, characterized in that: In step S2, one or more of the following solutions are used to adjust the pH value: 30% hydrochloric acid solution, 30% citric acid solution, and 50% acetic acid solution.

Images