Composite wall material microcapsule emulsion and preparation method thereof

Abstract

The invention provides a composite wall material microcapsule emulsion and a preparation method thereof, which are used for solving the problems of yellowing, harmful residues and no high temperature resistance. The invention relates to a composite wall material microcapsule emulsion, which comprises: essence; an SMA emulsifier and a Span80 emulsifier; the component A is prepared from aliphatic isocyanate, beta-cyclodextrin, ethylenediaminetetraacetic acid, polypropylene glycol or polyethylene glycol, and the molecular weight of the polypropylene glycol and the polyethylene glycol is smaller than or equal to 400; and water.

Description

Technical Field

[0001] The invention relates to the technical field of microcapsules, in particular to a microcapsule emulsion with a composite wall material made of multiple materials, and a preparation method of the microcapsule emulsion. Background Art

[0002] Microencapsulated emulsion is a technology that encapsulates active ingredients, such as fragrances, in tiny capsules and evenly disperses them in a liquid matrix. This emulsion provides sustained effects and protects active ingredients from environmental influences by controlling the release of active ingredients. It has a wide range of applications, covering the fields of cosmetics, food, medicine and textiles. For example, in cosmetics, it can be used for long-lasting moisturizing and oil control; in medicine, it controls drug release; in textiles, it gives clothes long-lasting fragrance or antibacterial and other functional properties.

[0003] Aromatic isocyanates are still widely used in the preparation of microcapsules, but because such materials are prone to yellowing and harmful chemicals such as formaldehyde or glutaraldehyde are easily left during the reaction, their application in the fields of daily chemicals and textiles is limited. As an alternative, aliphatic isocyanate systems have been developed, but the daily chemicals and textiles fields usually involve high-temperature disinfection processes, which requires microcapsules to have certain high-temperature resistance. Therefore, a single wall material can no longer meet the conditions, and it has become necessary to develop microcapsule emulsions with composite wall materials. Summary of the invention

[0004] The invention provides a composite wall material microcapsule emulsion and a preparation method thereof, which are used to solve the problems of yellowing, harmful residue and high temperature intolerance.

[0005] In order to achieve the above object, the present invention provides the following technical solutions: A composite wall material microcapsule emulsion, comprising: essence; SMA emulsifier, Span80 emulsifier; Aliphatic isocyanate, β-cyclodextrin, ethylenediaminetetraacetic acid, polypropylene glycol or polyethylene glycol, wherein the molecular weight of the polypropylene glycol and polyethylene glycol is less than or equal to 400; And water.

[0006] Furthermore, the dosage of the SMA emulsifier and the Span80 emulsifier is 5%-10% and 10%-20% of the dosage of the essence respectively.

[0007] Further, the weight ratio of the essence to the aliphatic isocyanate is (5-7):1; The weight ratios of ethylenediaminetetraacetic acid, beta-cyclodextrin, polypropylene glycol or polyethylene glycol to aliphatic isocyanate are 1:(4-5), 1:(20-30), and 1:(1-1.5) respectively.

[0008] Furthermore, the flavor includes one or more of the following: lavender flavor, citronella flavor, rose flavor, citrus flavor, cedar flavor, and ocean flavor.

[0009] Furthermore, the emulsion preparation method comprises: S10: Mix the essence and the aliphatic isocyanate in proportion to form an oil phase A; add the emulsifier SMA and the emulsifier Span80 into water respectively to form an aqueous phase B; drop the oil phase A into the aqueous phase B at a uniform speed within a time t1 for high-speed emulsification to obtain an emulsion A; S20: Add ethylenediaminetetraacetic acid, β-cyclodextrin, polyethylene glycol or polypropylene glycol into water to form aqueous phase C; add aqueous phase C dropwise into emulsion A, uniformly add aqueous phase C dropwise into emulsion A within time t2, stir and react at temperature T1 for 1 hour, heat to temperature T2, react for 2 hours, heat to temperature T3, and react for 2 hours; obtain microcapsule suspension, filter and purify to obtain microcapsule emulsion.

[0010] Furthermore, the weight ratio of the oil phase A to the water phase B is 1:2; the rotation speed in the high-speed emulsification process in step S10 is 8000 r / min, and the emulsification time is 10 min.

[0011] Furthermore, t1 and t2 are 10-20 min respectively; T1 is 40°C, T2 is 60°C, and T3 is 70°C.

[0012] Furthermore, the weight ratio of the flavor to the aliphatic isocyanate is (5-7):1; the weight of the emulsifier SMA is 5-10% of the flavor amount, and the amount of the emulsifier Span80 is 10-20% of the flavor amount; the weight ratios of ethylenediaminetetraacetic acid, β-cyclodextrin, polyethylene glycol or polypropylene glycol to aliphatic isocyanate are 1:(4-5), 1:(20-30), and 1:(1-1.5), respectively.

[0013] Furthermore, the amount of the flavor is 300g, the amount of the emulsifier SMA is 30g, the amount of Span80 is 15g, and the amount of water in step S10 is 495g; the amount of the aliphatic isocyanate is 47.5g, the amount of the β-cyclodextrin is 2g, the amount of ethylenediaminetetraacetic acid is 10g, the amount of polypropylene glycol is 40.5g, and the amount of water in step S20 is 60g.

[0014] Furthermore, the solid content was 40.82%, the weight loss rate was 45.28%, and the embedding efficiency was 87.73%.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The microcapsule emulsion prepared by the present invention is not prone to yellowing and the emulsion is uniform and stable; The wall material made by the reaction of aliphatic isocyanate (IPDI), β-cyclodextrin (β-CD), ethylenediaminetetraacetic acid EDTA, polyethylene glycol PEG or polypropylene glycol PPG with a molecular weight of less than or equal to 400 has the characteristics of high density and high temperature resistance, is suitable for use during high temperature disinfection, and is conducive to storage and transportation, reducing losses during storage and transportation; The microcapsule emulsion prepared by the method of the present invention does not have the problem of residual organic solvents such as formaldehyde and glutaraldehyde, and is more suitable for use in daily chemicals, textiles, and medical products; The microcapsule emulsion prepared by the present invention can be used by spraying or mixing and adding, and the production line of the existing product does not need to be changed. Only independent operation steps need to be added, and it can be put into industrial use, which is very conducive to industrialization. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a 10 μm scanning electron microscope image of the sample of Example 3 of the present invention; Figure 2 is a 2 μm scanning electron microscope image of the sample of Example 3 of the present invention; Figure 3 It is a solid content variation curve of the microcapsule emulsion of Example 8 of the present invention. DETAILED DESCRIPTION

[0017] The present invention will be described in detail below with reference to the accompanying drawings. In this article, the term "%" refers to mass fraction, the term "℃" refers to degrees Celsius, which is a temperature unit, the term "r / min" refers to the rotation speed per minute, which is a rotation speed unit, the term "microcapsule emulsion" refers to an emulsion containing microcapsules, the term "SMA" refers to styrene-maleic anhydride copolymer, and the term "Span80" refers to sorbitan oleate.

[0018] The solid content is calculated by the following formula: w 固含 =m1 / m0*100%, Among them, m 0 ： Weight of microcapsule solution input; m 1 ： The weight of the microcapsule solution after drying at 105°C for 2 hours.

[0019] The weight loss rate is calculated by the following formula: w 失重=(m1-m2) / m1*100%, Wherein, m1: weight of the microcapsule solution after drying at 105℃ for 2h; m 2： The weight of the microcapsule solution was dried at 105°C for 4 hours and then at 200°C for 2 hours.

[0020] Embedding rate = (M0-M1) / M*100%, Wherein, M is the total weight of the microcapsule emulsion, M0 is the amount of flavor input, and M1 is the mass of the unencapsulated flavor (the flavor microcapsules in the anhydrous ethanol treatment reactor are subjected to static sedimentation to obtain a residual liquid containing all the unencapsulated flavor microcapsules. The content of the unencapsulated flavor M1 is calculated based on the absorbance of the washing residual liquid).

[0021] This embodiment provides a composite wall material microcapsule emulsion, which consists of a core material, an emulsifier and a wall material; the core material is an essence, and there are many choices of essences, which can be one or a combination of the following: lavender essence, citronella essence, rose essence, citrus essence, cedar essence, and marine essence.

[0022] There are two types of emulsifiers, namely emulsifier SMA and emulsifier Span80. The reasons for selecting two emulsifiers are: first, the synergistic emulsification effect of emulsifiers is utilized. SMA emulsifier, as a polymer emulsifier, has excellent stability and emulsification performance, while Span80, as a non-ionic emulsifier, has good wetting and dispersing properties. The synergistic effect of the two can improve the uniformity and stability of the microcapsule system; second, since SMA emulsifier and Span80 emulsifier have different hydrophilic-lipophilic balance (HLB) values, the combined use can better control the formation process of microcapsules and improve the embedding efficiency of active ingredients. SMA emulsifier can form a stable emulsion system and reduce the leakage of active ingredients, while Span80 can enhance the compatibility of emulsifiers with oil phases and promote the uniform distribution and embedding of active ingredients; third, the combined use of SMA emulsifier and Span80 emulsifier can better control the particle size and distribution of microcapsules. The polymer chains of the SMA emulsifier can form a larger interface film and stabilize microcapsules with larger particle sizes, while the low molecular weight of Span80 helps to form microcapsules with smaller particle sizes. By adjusting the ratio of the two emulsifiers, the particle size and distribution of the microcapsules can be precisely controlled; fourthly, the polymer characteristics of the SMA emulsifier make the microcapsules formed by it have higher mechanical strength and heat resistance, while Span80 can improve the flexibility and stability of the microcapsules. The combined use can improve the overall mechanical properties of the microcapsules and make them more stable during processing and storage.

[0023] The wall material is formed by the reaction of aliphatic isocyanate (IPDI), β-cyclodextrin (β-CD), ethylenediaminetetraacetic acid EDTA, polyethylene glycol PEG or polypropylene glycol PPG with a molecular weight of less than or equal to 400. Aliphatic isocyanate IPDI is different from aromatic isocyanate and is not easy to yellow. IPDI reacts with PPG / PEG to form polyurethane, IPDI reacts with β-CD to form polyurethane, and IPDI reacts with EDTA to form polyurea. The wall material is composed of a mixture of various polyureas and polyurethanes, making the wall material highly dense and high temperature resistant.

[0024] In the following examples, the dosage of each reactant of the core material, emulsifier and wall material is adjusted to determine the optimal dosage and dosage range. The specific ratio is shown in the following table.

[0025] The above examples tested and calculated the solid content, weight loss rate and embedding rate, and the experimental results are as follows: From the above results, it can be seen that the dosage of emulsifier SMA is 5%-10% of the dosage of flavor, the dosage of emulsifier Span is 10%-20% of the dosage of flavor, the weight ratio of flavor to IPDI is (5-7):1, and the weight ratios of EDTA, β-CD, PPG / PEG and IPDI are 1:(4-5), 1:(20-30), and 1:(1-1.5), respectively.

[0026] Figure 1 Provides a 10 μm scanning electron microscope image of the microcapsule emulsion tested using Example 3 as a sample, Figure 2 A scanning electron microscope image of a 2 μm microcapsule emulsion tested using Example 3 as a sample is provided. From the SEM image, it can be seen that the microcapsule emulsion has a high embedding rate, and the microspheres have uniform morphology and size distribution.

[0027] This example provides a preparation method based on the formula of Example 3, and the specific preparation steps are: S10: Mix the essence and the aliphatic isocyanate in proportion to form an oil phase A; add the emulsifier SMA and the emulsifier Span80 into water respectively to form an aqueous phase B; drop the oil phase A into the aqueous phase B at a uniform speed within a time t1 for high-speed emulsification to obtain an emulsion A; S20: Add ethylenediaminetetraacetic acid, β-cyclodextrin, polyethylene glycol or polypropylene glycol into water to form aqueous phase C; add aqueous phase C dropwise into emulsion A, uniformly add aqueous phase C dropwise into emulsion A within time t2, stir and react at temperature T1 for 1 hour, heat to temperature T2, react for 2 hours, heat to temperature T3, and react for 2 hours; obtain microcapsule suspension, filter and purify to obtain microcapsule emulsion.

[0028] Among them, the weight ratio of oil phase A to water phase B is 1:2; the rotation speed in the high-speed emulsification process in step S10 is 8000r / min, and the emulsification time is 10min; t1 and t2 are 10-20min respectively; T1 is 40°C, T2 is 60°C, and T3 is 70°C.

[0029] This example is a sustained release experiment of the sample of Example 7. The solid content changes after drying at 105°C, 150°C, and 180°C for 10 hours were respectively tested. The mass at 0 hours was converted to 100% solid content. The results are as follows: Figure 3 As shown in the figure, the solid content of the sample decreased rapidly within 1 hour under the conditions of 105℃, 150℃ and 180℃, but it could be kept decreasing slowly during the process of 2-10 hours, and at 10 hours, the solid content was still 20% or more. In addition, although the temperature difference is large, the change of solid content is relatively small. This experiment proves that even in the high temperature environment of 150℃ and 180℃, it can maintain a good slow release effect, thus proving the high temperature resistance of the wall material.

[0030] This embodiment provides a method for using a microcapsule emulsion containing a fragrance, wherein the microcapsule emulsion prepared in the above embodiment is directly sprayed on the surface of a target object or added into the target object, and the target object can be subsequently sterilized at a high temperature within a range of 180° C. The target objects referred to in this embodiment include, but are not limited to: fabrics, laundry detergent, mosquito repellent, and sanitary products.

[0031] Although the present invention has been disclosed as above with preferred embodiments, it is not intended to limit the present invention. A person with ordinary knowledge in the technical field to which the present invention belongs may make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be determined by the definition of the claims.

Claims

1. A composite wall material microcapsule emulsion, characterized in that: include: essence; SMA emulsifier, Span80 emulsifier; Aliphatic isocyanate, β-cyclodextrin, ethylenediaminetetraacetic acid, polypropylene glycol or polyethylene glycol, wherein the molecular weight of the polypropylene glycol and polyethylene glycol is less than or equal to 400; And water.

2. A composite wall material microcapsule emulsion according to claim 1, characterized in that: The dosage of the SMA emulsifier and the Span80 emulsifier is 5%-10% and 10%-20% of the dosage of the essence respectively.

3. A composite wall material microcapsule emulsion according to claim 2, characterized in that: The weight ratio of the flavor to the aliphatic isocyanate is (5-7):1; The weight ratios of ethylenediaminetetraacetic acid, beta-cyclodextrin, polypropylene glycol or polyethylene glycol to aliphatic isocyanate are 1:(4-5), 1:(20-30), and 1:(1-1.5) respectively.

4. The composite wall material microcapsule emulsion according to claim 3, characterized in that: The flavor includes one or more of the following: lavender flavor, citronella flavor, rose flavor, citrus flavor, cedar flavor, and ocean flavor.

5. The composite wall material microcapsule emulsion according to claim 1, characterized in that: The emulsion preparation method comprises: S10: Mix the essence and the aliphatic isocyanate in proportion to form an oil phase A; add the emulsifier SMA and the emulsifier Span80 into water respectively to form an aqueous phase B; drop the oil phase A into the aqueous phase B at a uniform speed within a time t1 for high-speed emulsification to obtain an emulsion A; S20: Add ethylenediaminetetraacetic acid, β-cyclodextrin, polyethylene glycol or polypropylene glycol into water to form aqueous phase C; add aqueous phase C dropwise into emulsion A, uniformly add aqueous phase C dropwise into emulsion A within time t2, stir and react at temperature T1 for 1 hour, heat to temperature T2, react for 2 hours, heat to temperature T3, and react for 2 hours; obtain microcapsule suspension, filter and purify to obtain microcapsule emulsion.

6. A composite wall material microcapsule emulsion according to claim 5, characterized in that: The weight ratio of the oil phase A to the water phase B is 1:2; the rotation speed in the high-speed emulsification process in step S10 is 8000 r / min, and the emulsification time is 10 min.

7. The composite wall material microcapsule emulsion according to claim 5, characterized in that: t1 and t2 are 10-20min respectively; T1 is 40°C, T2 is 60°C, and T3 is 70°C.

8. The composite wall material microcapsule emulsion according to claim 7, characterized in that: The weight ratio of the flavor to the aliphatic isocyanate is (5-7):1; the weight of the emulsifier SMA is 5-10% of the flavor, and the amount of the emulsifier Span80 is 10-20% of the flavor; the weight ratios of ethylenediaminetetraacetic acid, β-cyclodextrin, polyethylene glycol or polypropylene glycol to aliphatic isocyanate are 1:(4-5), 1:(20-30), and 1:(1-1.5), respectively.

9. The composite wall material microcapsule emulsion according to claim 8, characterized in that: The amount of the flavor is 300g, the amount of the emulsifier SMA is 30g, the amount of Span80 is 15g, and the amount of water in step S10 is 495g; the amount of the aliphatic isocyanate is 47.5g, the amount of the β-cyclodextrin is 2g, the amount of ethylenediaminetetraacetic acid is 10g, the amount of polypropylene glycol is 40.5g, and the amount of water in step S20 is 60g.

10. The composite wall material microcapsule emulsion according to claim 9, characterized in that: The solid content was 40.82%, the weight loss rate was 45.28%, and the embedding efficiency was 87.73%.

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