A kind of fragrance microcapsule and its preparation method and application

Abstract

The invention discloses a fragrance microcapsule and a preparation method thereof, aiming to provide a fragrance microcapsule with high core material encapsulation rate, high capsule wall density, long core material release time and good safety; the preparation method is simple to operate and uses less raw materials; the technical scheme comprises the following raw materials in weight percentage: 10%-60% of oil phase fragrance core material, 0.1%-5% of polyurethane, 0.01%-2% of polyacid salt, 0.01%-2% of polyamine salt, 0.01%-2% of polyethylene glycol p-isooctylphenyl ether, 0.001%-1% of crosslinking agent, 40%-90% of water by weight, and the sum of various components is 100%; the invention belongs to the technical field of daily necessities.

Description

Technical Field

[0001] The invention discloses a microcapsule, in particular to a fragrance microcapsule. The invention provides a preparation method of the fragrance microcapsule and belongs to the technical field of daily chemical products. Background Art

[0002] Microcapsules have unique application value in many fields, such as flavors, inks, and pesticide carriers. Fragrance microcapsules are extremely tiny capsules formed by encapsulating the desired fragrance in a polymer compound as the wall material. Fragrance microcapsules are favored by consumers because of their good sustained release properties.

[0003] With the development of science and technology, higher requirements are put forward for the embedding rate, release rate and fragrance retention time of spice microcapsules. CN112625814A discloses a flavor composite microcapsule, which includes a capsule wall and a capsule core, wherein the capsule wall is a polyurethane resin, and the capsule core is made of the following raw materials in mass percentage: 60.0-90.0% of sodium fatty acid, 10.0-30.0% of water, 0-20.0% of surfactant, 0.01-5.0% of water softener, 0-1.5% of traditional flavor, 0.05-1.5% of microcapsule flavor, 0.1-3.0% of stabilizer, and 0-10.0% of other additives. However, although the microcapsule flavor can release a unique composite fragrance and has a high embedding rate, these microcapsule flavors are easy to stick together after being stacked for a period of time, which is more suitable for immediate use and is not conducive to long-term storage. CN114829567A discloses a composite capsule wall microcapsule flavor, which is composed of an oily flavor located inside, a first layer of microcapsule wall located in the middle, and an outer capsule wall located in the outermost layer; the first layer of microcapsule wall located in the middle is composed of sodium alginate and carboxymethyl fiber, and the outer capsule wall located in the outermost layer is composed of polyurethane. The double-layer capsule wall microcapsule flavor uses polyurethane, sodium alginate and carboxymethyl fiber as capsule walls, which have poor solubility or low density, resulting in the capsule core coated in the capsule wall having deficiencies in microencapsulation rate, fragrance retention time, fragrance release or solubility. At the same time, the production process of flavor microcapsules is cumbersome and time-consuming, the release mode is uncontrollable, the price is too high, and the core material flavor is easily deteriorated due to excessive temperature; there is no report on polyurethane microcapsules with high encapsulation rate and high stability and their preparation methods. Summary of the invention

[0004] In order to overcome the above-mentioned technical defects, the first object of the present invention is to provide a method for preparing polyurethane microcapsules with simple operation, small amount of raw materials, high encapsulation rate and good stability.

[0005] The second object of the present invention is to provide a fragrance microcapsule, which has a high core material encapsulation rate, high capsule wall density, long core material release time and good safety.

[0006] A fragrance microcapsule comprises the following raw materials in weight percentage: 10%-60% of an oil phase fragrance core material, 0.1%-5% of polyurethane, 0.01%-2% of a polyacid salt, 0.01%-2% of a polyamine salt, 0.01%-2% of polyethylene glycol p-isooctylphenyl ether, 0.001%-1% of a crosslinking agent, 40%-90% of water by weight, and the sum of all components being 100%.

[0007] Furthermore, in the above-mentioned flavor microcapsule, the oil-phase flavor core material is encapsulated in the microcapsule.

[0008] Furthermore, in the above-mentioned fragrance microcapsule, the capsule surface is composited by polyurethane, sodium polymethacrylate and polyallylamine hydrochloride.

[0009] Furthermore, in the above-mentioned fragrance microcapsule, the polyurethane is an isophorone diisocyanate / adipic acid / triethylene glycol / dimethylol propionic acid copolymer, and its molecular weight is 30,000-80,000.

[0010] Furthermore, in the above-mentioned flavor microcapsule, the oil phase flavor core material is a mixture of essential oil, tricyclodecenyl acetate and isopropyl myristate.

[0011] Furthermore, in the above-mentioned spice microcapsule, the mass ratio of the essential oil, tricyclodecenyl acetate and isopropyl myristate is: 5-13:2-4:2-4.

[0012] Furthermore, in the above-mentioned fragrance microcapsule, the polyacid salt is sodium polymethacrylate, and its molecular weight is 50,000-200,000; the polyamine salt is polyallylamine hydrochloride, and its molecular weight is 20,000-60,000; and the cross-linking agent is calcium chloride.

[0013] Furthermore, in the above-mentioned spice microcapsule, the essential oil is one of lavender oil, rose oil, tea tree oil, chamomile oil, rosemary oil, sandalwood oil, bergamot oil, jasmine oil, geranium oil, peppermint oil, and sage oil.

[0014] The second technical solution provided by the present invention is a method for preparing the above-mentioned fragrance microcapsules, which comprises the following steps in sequence:

[0015] 1) Weigh each component;

[0016] 2) mixing essential oil, tricyclodecenyl acetate and isopropyl myristate to prepare an oil phase mixture;

[0017] 3) dispersing the oil phase mixture prepared in step 2) in an aqueous solution containing a surfactant to form a uniform oil-in-water suspension;

[0018] 4) adding polyurethane to the oil-in-water suspension and performing flocculation at room temperature;

[0019] 5) The polyacid salt and the polyamine salt are mixed into the suspension formed in step 4), and then a cross-linking agent is added, and the mixture is heated to 35-75° C. for curing to obtain polyurethane microcapsules encapsulating the functional factors.

[0020] Preferably, the surfactant is Triton X-100, and its concentration in the aqueous solution is 2 wt %.

[0021] The fragrance microcapsules provided by the present invention are used as additives for daily chemical products, such as shampoo and laundry detergent additives.

[0022] Compared with the prior art, the technical solution provided by the present invention has the following beneficial effects:

[0023] 1. The technical solution provided by the present invention adopts polyurethane and polyacid / polyamine salt flocculation as composite wall materials to enhance stability and improve the core material encapsulation rate, which is as high as more than 95%; and reduces the sudden release of fragrance, and the release mode is extremely slow, which can be extended to a maximum of 150 days, so that the released fragrance can exert its efficacy for a long time, and at the same time, the fragrance can maintain high activity during the entire preparation process and treatment process, that is, it will not be inactivated.

[0024] 2. The microcapsules prepared by the technical solution provided by the present invention have a particle size that can be adjusted from 0.1 microns to 50 microns according to different needs, and the size is precisely controllable. The surface of the particles is smooth and round, and the particles are regular and non-adhesive. The system product is a white, delicate, and fluid fluid that will not agglomerate or adhere, and has good redispersibility. It can be used in the preparation of other flavor sustained-release or controlled-release microcapsules, and the preparation process does not pollute the environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is an optical microscope photograph of the microcapsules prepared in Example 1 of the present invention;

[0026] Figure 2 is a fragrance release curve of the microcapsules prepared in Example 1 of the present invention;

[0027] Figure 3 is a high performance liquid chromatography (HPLC) chart of the microcapsules prepared in Example 1 of the present invention;

[0028] Figure 4 is a high performance liquid chromatography (HPLC) chart of the microcapsules prepared in Comparative Example 1 of the present invention;

[0029] Figure 5 is a high performance liquid chromatography (HPLC) chart of the microcapsules prepared in Comparative Example 2 of the present invention;

[0030] Figure 6 It is a high performance liquid chromatography (HPLC) chart of the microcapsules prepared in Comparative Example 3 of the present invention. DETAILED DESCRIPTION

[0031] The claims of the present invention are further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0032] Example 1

[0033] The present embodiment provides a fragrance microcapsule, which is prepared by the following method: 0.9g lavender oil, 0.3g tricyclodecenyl acetate and 0.3g isopropyl myristate are fully mixed at 25°C, and then mixed with 2.4g 2wt% Triton X-100 (polyethylene glycol p-isooctylphenyl ether) aqueous solution in a 10mL glass vial, and stirred at a constant stirring speed of 1000RPM for 3min to obtain a uniform emulsion. 0.1g polyurethane-15 is added to the emulsion, the mixture is adjusted to pH 5.5 with 0.1M sodium hydroxide solution, and the emulsion is stirred at a constant stirring speed of 1000RPM for 4h to form a polyurethane microcapsule loaded with fragrance.

[0034] 0.25 mL of 200 mg / mL sodium polymethacrylate aqueous solution was added to the polyurethane microcapsules loaded with fragrances, and stirred for 20 min. No serious particle aggregation was observed in the process. Then 0.25 mL of 200 mg / mL polyallylamine hydrochloride solution was added to the microcapsules. After stirring at room temperature for 20 min, 0.25 mL of 200 mg / mL sodium polymethacrylate aqueous solution was added and stirred for 20 min to form a precipitate. The precipitate was washed with 0.01 M phosphate buffer solution (PBS), and the precipitate was collected. The pH of the solution was controlled at 5.5 by 0.1 M sodium hydroxide and hydrochloric acid solutions. Finally, 0.25 mL of 200 mg / mL calcium chloride solution was added to the microcapsules. After stirring at room temperature for 20 min, the microcapsule system was heated to 55°C and stirred for 2 h to obtain fragrance microcapsule sample 1.

[0035] Example 2

[0036] The present embodiment provides a fragrance microcapsule, which is prepared by the following method: 0.5g rose oil, 0.2g tricyclodecenyl acetate and 0.2g isopropyl myristate are fully mixed at 25°C, and then mixed with 2.4g 2wt% Triton X-100 (polyethylene glycol p-isooctylphenyl ether) aqueous solution in a 10mL glass vial, and stirred at a constant stirring speed of 1000RPM for 3min to obtain a uniform emulsion. 0.2g polyurethane-15 is added to the emulsion, the mixture is adjusted to pH 5.5 with 0.1M sodium hydroxide solution, and the emulsion is stirred at a constant stirring speed of 1000RPM for 4h to form a polyurethane microcapsule loaded with fragrance.

[0037] 0.05 mL of 200 mg / mL sodium polymethacrylate aqueous solution was added to the polyurethane microcapsules loaded with fragrances. After stirring for 20 minutes, no serious particle aggregation was observed in the process. Then 0.05 mL of 200 mg / mL polyallylamine hydrochloride solution was added to the microcapsules. After stirring at room temperature for 20 minutes, 0.1 mL of 200 mg / mL sodium polymethacrylate aqueous solution was added and stirred for 20 minutes to form a precipitate. The precipitate was washed with 0.01 M phosphate buffer solution (PBS), the precipitate was collected, and the pH of the solution was controlled at 5.5 by 0.1 M sodium hydroxide and hydrochloric acid solutions. Finally, 0.05 mL of 200 mg / mL calcium chloride solution was added to the microcapsules. After stirring at room temperature for 20 minutes, the microcapsule system was heated to 50°C and stirred for 2 hours to obtain fragrance microcapsule sample 2.

[0038] Example 3

[0039] The present embodiment provides a fragrance microcapsule, which is prepared by the following method: 0.8g tea tree oil, 0.4g tricyclodecenyl acetate and 0.2g isopropyl myristate are fully mixed at 25°C, and then mixed with 2.4g 2wt% Triton X-100 (polyethylene glycol p-isooctylphenyl ether) aqueous solution in a 100mL glass vial, and stirred at a constant stirring speed of 1000RPM for 3min to obtain a uniform emulsion. 0.3g polyurethane-15 is added to the emulsion, the mixture is adjusted to pH 5.5 with 0.1M sodium hydroxide solution, and the emulsion is stirred at a constant stirring speed of 1000RPM for 4h to form a polyurethane microcapsule loaded with fragrance.

[0040] 5 mL of 200 mg / mL sodium polymethacrylate aqueous solution was added to the polyurethane microcapsules loaded with fragrances, and stirred for 20 min. No serious particle aggregation was observed in the process. Then 5 mL of 200 mg / mL polyallylamine hydrochloride solution was added to the microcapsules. After stirring at room temperature for 20 min, 2 mL of 200 mg / mL sodium polymethacrylate aqueous solution was added and stirred for 20 min to form a precipitate. The precipitate was washed with 0.01 M phosphate buffer solution (PBS), and the precipitate was collected. The pH of the solution was controlled at 5.5 by 0.1 M sodium hydroxide and hydrochloric acid solutions. Finally, 0.1 mL of 200 mg / mL calcium chloride solution was added to the microcapsules. After stirring at room temperature for 20 min, the microcapsule system was heated to 75 ° C and stirred for 2 h to obtain fragrance microcapsule sample 3.

[0041] Example 4

[0042] The present embodiment provides a fragrance microcapsule, which is prepared by the following method: 1.3g of chamomile oil, 0.4g of tricyclodecenyl acetate and 0.4g of isopropyl myristate are fully mixed at 25°C, and then mixed with 2.4g of 2wt% Triton X-100 aqueous solution in a 10mL glass vial, and stirred at a constant stirring speed of 1000RPM for 3min to obtain a uniform emulsion. 5g of polyurethane-15 is added to the emulsion, the mixture is adjusted to pH 5.5 with 0.1M sodium hydroxide solution, and the emulsion is stirred at a constant stirring speed of 1000RPM for 4h to form a polyurethane microcapsule loaded with fragrance.

[0043] 0.5 mL of 200 mg / mL sodium polymethacrylate aqueous solution was added to the polyurethane microcapsules loaded with fragrances, and stirred for 20 min. No serious particle aggregation was observed in the process. Then 0.5 mL of 200 mg / mL polyallylamine hydrochloride solution was added to the microcapsules. After stirring at room temperature for 20 min, 1 mL of 200 mg / mL sodium polymethacrylate aqueous solution was added and stirred for 20 min to form a precipitate. The precipitate was washed with 0.01 M phosphate buffer solution (PBS), and the precipitate was collected. The pH of the solution was controlled at 5.5 by 0.1 M sodium hydroxide and hydrochloric acid solutions. Finally, 0.5 mL of 200 mg / mL calcium chloride solution was added to the microcapsules. After stirring at room temperature for 20 min, the microcapsule system was heated to 60°C and stirred for 3 h to obtain fragrance microcapsule sample 4.

[0044] Example 5

[0045] The present embodiment provides a fragrance microcapsule, which is prepared by the following method: 1.0g rosemary oil, 0.3g tricyclodecenyl acetate and 0.2g isopropyl myristate are fully mixed at 25°C, and then mixed with 2.4g 2wt% Triton X-100 aqueous solution in a 10mL glass vial, and stirred at a constant stirring speed of 1000RPM for 3min to obtain a uniform emulsion. 1g polyurethane-15 is added to the emulsion, the mixture is adjusted to pH 5.5 with 0.1M sodium hydroxide solution, and the emulsion is stirred at a constant stirring speed of 1000RPM for 4h to form a polyurethane microcapsule loaded with fragrance.

[0046] 1 mL of 200 mg / mL sodium polymethacrylate aqueous solution was added to the polyurethane microcapsules loaded with fragrances. After stirring for 20 min, no serious particle aggregation was observed in the process. Then 1 mL of 200 mg / mL polyallylamine hydrochloride solution was added to the microcapsules. After stirring at room temperature for 20 min, 1.5 mL of 200 mg / mL sodium polymethacrylate aqueous solution was added and stirred for 20 min to form a precipitate. The precipitate was washed with 0.01 M phosphate buffer solution (PBS), the precipitate was collected, and the pH of the solution was controlled at 5.5 by 0.1 M sodium hydroxide and hydrochloric acid solution. Finally, 0.4 mL of 200 mg / mL calcium chloride solution was added to the microcapsules. After stirring at room temperature for 20 min, the microcapsule system was heated to 65°C and stirred for 5 h to obtain fragrance microcapsule sample 5.

[0047] Example 6

[0048] The present embodiment provides a fragrance microcapsule, which is prepared by the following method: 1.1g of sandalwood oil, 0.35g of tricyclodecenyl acetate and 0.35g of isopropyl myristate are fully mixed at 25°C, and then mixed with 2.4g of 2wt% Triton X-100 aqueous solution in a 10mL glass vial, and stirred at a constant stirring speed of 1000RPM for 3min to obtain a uniform emulsion. 2g of polyurethane-15 is added to the emulsion, the mixture is adjusted to pH 5.5 with 0.1M sodium hydroxide solution, and the emulsion is stirred at a constant stirring speed of 1000RPM for 4h to form a polyurethane microcapsule loaded with fragrance.

[0049] 0.5 mL of 200 mg / mL sodium polymethacrylate aqueous solution was added to the polyurethane microcapsules loaded with fragrances, and stirred for 20 min. No serious particle aggregation was observed in the process. Then 0.5 mL of 200 mg / mL polyallylamine hydrochloride solution was added to the microcapsules. After stirring at room temperature for 20 min, 0.5 mL of 200 mg / mL sodium polymethacrylate aqueous solution was added and stirred for 20 min to form a precipitate. The precipitate was washed with 0.01 M phosphate buffer solution (PBS), and the precipitate was collected. The pH of the solution was controlled at 5.5 by 0.1 M sodium hydroxide and hydrochloric acid solutions. Finally, 0.6 mL of 200 mg / mL calcium chloride solution was added to the microcapsules. After stirring at room temperature for 20 min, the microcapsule system was heated to 55 ° C and stirred for 2 h to obtain fragrance microcapsule sample 6.

[0050] The polyurethane described in Examples 1 to 6 is an isophorone diisocyanate / adipic acid / triethylene glycol / dimethylol propionic acid copolymer, and its molecular weight is 30,000-80,000;

[0051] The molecular weight of the sodium polymethacrylate is 50,000-200,000.

[0052] The molecular weight of the polyallylamine hydrochloride is 20000-60000.

[0053] Comparative Example 1

[0054] The fragrance microcapsules provided in this comparative example differ from the technical solutions provided in the examples in that sodium polymethacrylate is missing, and other experimental processes and parameters are the same as those in Example 1.

[0055] The present embodiment provides a fragrance microcapsule, which is prepared by the following method: 0.5g rose oil, 0.2g tricyclodecenyl acetate and 0.2g isopropyl myristate are fully mixed at 25°C, and then mixed with 2.4g 2wt% Triton X-100 aqueous solution in a 10mL glass vial, and stirred at a constant stirring speed of 1000RPM for 3min to obtain a uniform emulsion. 0.2g polyurethane-15 is added to the emulsion, the mixture is adjusted to pH 5.5 with 0.1M sodium hydroxide solution, and the emulsion is stirred at a constant stirring speed of 1000RPM for 4h to form a polyurethane microcapsule loaded with fragrance.

[0056] 0.05 mL of 200 mg / mL polyallylamine hydrochloride solution was added to the polyurethane microcapsules loaded with fragrances. After stirring at room temperature for 20 min, a precipitate was formed. The mixture was then washed with 0.01 M phosphate buffer solution (PBS), the precipitate was collected, and the pH of the solution was controlled at 5.5 by 0.1 M sodium hydroxide and hydrochloric acid solutions. Finally, 0.05 mL of 200 mg / mL calcium chloride solution was added to the microcapsules. After stirring at room temperature for 20 min, the microcapsule system was heated to 50 ° C and stirred for 2 h to obtain fragrance microcapsule comparison sample 1.

[0057] Comparative Example 2

[0058] The fragrance microcapsules provided in this comparative example differ from the technical solutions provided in the examples in that polyallylamine hydrochloride is missing, and other experimental processes and parameters are the same as those in Example 1.

[0059] The present embodiment provides a fragrance microcapsule, which is prepared by the following method: 0.5g rose oil, 0.2g tricyclodecenyl acetate and 0.2g isopropyl myristate are fully mixed at 25°C, and then mixed with 2.4g 2wt% Triton X-100 aqueous solution in a 10mL glass vial, and stirred at a constant stirring speed of 1000RPM for 3min to obtain a uniform emulsion. 0.2g polyurethane-15 is added to the emulsion, the mixture is adjusted to pH 5.5 with 0.1M sodium hydroxide solution, and the emulsion is stirred at a constant stirring speed of 1000RPM for 4h to form a polyurethane microcapsule loaded with fragrance.

[0060] 0.05 mL of 200 mg / mL sodium polymethacrylate aqueous solution was added to the fragrance-loaded polyurethane microcapsules and stirred for 20 min. No serious particle aggregation was observed during the process. Then 0.05 mL of deionized water was added to the microcapsules and stirred at room temperature for 20 min. Then, 0.1 mL of 200 mg / mL sodium polymethacrylate aqueous solution was added and stirred for 20 min to form a precipitate. The precipitate was washed with 0.01 M phosphate buffer solution (PBS), and the precipitate was collected. The pH of the solution was controlled at 5.5 by 0.1 M sodium hydroxide and hydrochloric acid solutions. Finally, 0.05 mL of 200 mg / mL calcium chloride solution was added to the microcapsules. After stirring at room temperature for 20 min, the microcapsule system was heated to 50 ° C and stirred for 2 h to obtain fragrance microcapsule sample 2.

[0061] Comparative Example 3

[0062] The fragrance microcapsules provided in this comparative example are different from the technical solutions provided in the examples in that polyurethane is replaced by polymethyl methacrylate, and the other experimental processes and parameters are the same as those in Example 1.

[0063] The present embodiment provides a fragrance microcapsule, which is prepared by the following method: 0.5g rose oil, 0.2g tricyclodecenyl acetate and 0.2g isopropyl myristate are fully mixed at 25°C, and then mixed with 2.4g 2wt% Triton X-100 aqueous solution in a 10mL glass vial, and stirred at a constant stirring speed of 1000RPM for 3min to obtain a uniform emulsion. 0.2g polymethyl methacrylate (molecular weight 30000) is added to the emulsion, the mixture is adjusted to pH 5.5 with 0.1M sodium hydroxide solution, and the emulsion is stirred at a constant stirring speed of 1000RPM for 4h to form a microcapsule loaded with fragrance.

[0064] 0.05 mL of 200 mg / mL sodium polymethacrylate aqueous solution was added to the microcapsules loaded with fragrances, and stirred for 20 min. No serious particle aggregation was observed in the process. Then 0.05 mL of 200 mg / mL polyallylamine hydrochloride solution was added to the microcapsules. After stirring at room temperature for 20 min, 0.1 mL of 200 mg / mL sodium polymethacrylate aqueous solution was added and stirred for 20 min to form a precipitate. The precipitate was washed with 0.01 M phosphate buffer solution (PBS), and the precipitate was collected. The pH of the solution was controlled at 5.5 by 0.1 M sodium hydroxide and hydrochloric acid solutions. Finally, 0.05 mL of 200 mg / mL calcium chloride solution was added to the microcapsules. After stirring at room temperature for 20 min, the microcapsule system was heated to 50°C and stirred for 2 h to obtain fragrance microcapsule sample 2.

[0065] In order to demonstrate the effect of the technical solution provided by the present application, the following is a test experiment of the technical solution provided by Example 1 of the present application:

[0066] The microcapsule sample 1 prepared in Example 1 and Comparative Examples 1 to 3 was used as the experimental object to detect the fragrance loading amount:

[0067] 0.1 g of microcapsule solution was mixed into 10 mL of n-hexane solution to extract the unloaded fragrance. The fragrance and internal standard concentrations were detected by a high performance liquid chromatography (HPLC) system with an Inertsil YMC-ODS-AQ 3F C18 column coupled to a SciexAPI III+ triple quadrupole mass spectrometer. The entrapment rate of the fragrance core material and the entrapment efficiency of the fragrance were then calculated from a calibration curve obtained with a fragrance / methanol solution of known concentration. The core material entrapment rate and fragrance entrapment efficiency were calculated according to the following formula:

[0068] Perfume encapsulation rate (weight %) = (amount of perfume added - weight of unencapsulated perfume) / total amount of microcapsule system × 100%;

[0069] Fragrance encapsulation efficiency (weight %) = (fragrance dosage - unencapsulated fragrance weight) / fragrance dosage × 100%;

[0070] Flavor encapsulation rate % Packaging efficiency % Example 1 29.9 99.7 Example 2 23.9 99.6 Example 3 8.5 98.8 Example 4 17.4 99.4 Comparative Example 1 12.1 48.4 Comparative Example 2 5.1 21.2 Comparative Example 3 10.3 42.9

[0071] It can be seen from the above table that the fragrance encapsulation efficiency of the polyurethane / polyacid / polyamine flocculation microcapsule sample is 99.0%. It can be seen that the fragrance core material encapsulation rate and encapsulation efficiency of the polyurethane / polyacid / polyamine flocculation microcapsule are extremely high, while the encapsulation efficiency of comparative examples 1-3 is less than 50%.

[0072] To measure the release behavior of the fragrance from the microcapsules, 2 mL of the fragrance-loaded microcapsule sample 1 dispersion (0.5 mg / mL in 0.01 M PBS) was transferred to a dialysis membrane bag (MWCO: 1000) and then dialyzed in 20 mL of 0.01 M PBS controlled at pH 5.0 at 37°C with gentle shaking. At predetermined time intervals, the aqueous solution samples were harvested and analyzed by HPLC / MS, and the spectra were referred to Figure 3-6 The fragrance concentration was determined using a standard curve obtained using fragrance solutions of known concentrations. In all steps, the cumulative release expressed as the total percentage of fragrance released was calculated as Wt / W×100%, where Wt is the cumulative weight of the functional factor released by the desired time ti and W is the total weight of the encapsulated functional factor. The core material release curve of the microcapsules in Sample 1 is shown in Figure 2 As shown, from Figure 2 It can be seen that the encapsulated functional factor - fragrance is released very slowly from the microcapsule, and it takes 120 days to reach the release equilibrium point. After 180 days, only less than 40% of the fragrance leaks out. Therefore, the prepared microcapsule sample has a high encapsulation efficiency and sustained-release effect for the functional factor.

[0073] The above is only a preferred embodiment of the present invention. It should be pointed out that ordinary technicians in this technical field can make several improvements and supplements without departing from the method of the present invention. These improvements and supplements should also be regarded as the scope of protection of the present invention.

Claims

1. A fragrance microcapsule, characterized in that: The invention comprises the following raw materials in weight percentage: 10%-60% of oil phase flavor core material, 0.1%-5% of polyurethane, 0.01%-2% of polyacid salt, 0.01%-2% of polyamine salt, 0.01%-2% of polyethylene glycol p-isooctylphenyl ether, 0.001%-1% of crosslinking agent, 40%-90% of water, and the sum of the components is 100%; The oil phase fragrance core material is encapsulated in a microcapsule; the oil phase fragrance core material is a mixture of essential oil, tricyclodecenyl acetate and isopropyl myristate in a mass ratio of 5-13:2-4:2-4; The surface of the microcapsule is composited with polyurethane, sodium polymethacrylate and polyallylamine hydrochloride; The polyurethane is a copolymer of isophorone diisocyanate / adipic acid / triethylene glycol / dimethylol propionic acid, and its molecular weight is 30000-80000; The polyacid is sodium polymethacrylate with a molecular weight of 50,000-200,000; The polyamine salt is polyallylamine hydrochloride with a molecular weight of 20000-60000; The cross-linking agent is calcium chloride; It is prepared by the following method: 1) Weigh each component according to the above weight percentage; 2) mixing the essential oil, tricyclodecenyl acetate and isopropyl myristate to prepare an oil phase mixture; 3) dispersing the oil phase mixture prepared in step 2) in an aqueous solution containing a surfactant to form a uniform oil-in-water suspension; 4) Adding polyurethane to the oil-in-water suspension and coagulating at room temperature; 5) The polyacid salt and the polyamine salt are mixed into the suspension formed in step 4), and then a cross-linking agent is added, and the mixture is heated to 35-75° C. for curing to obtain polyurethane microcapsules encapsulating functional factors.

2. A fragrance microcapsule according to claim 1, characterized in that: The essential oil is one of lavender oil, rose oil, tea tree oil, chamomile oil, rosemary oil, sandalwood oil, bergamot oil, jasmine oil, geranium oil, peppermint oil and sage oil.

3. Use of the fragrance microcapsules described in claim 1 as additives for daily chemical products.

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