A microcapsule with a hydrophilic / hydrophobic laminated shell structure and its preparation method and application

Abstract

The present invention discloses a microcapsule with a hydrophilic / hydrophobic laminated shell structure, a preparation method and an application thereof, wherein the shell layer of the microcapsule comprises at least two layers, one layer being a hydrophobic polymer material layer and the other being a hydrophilic polymer material layer. Due to the introduction of a composite shell structure of a hydrophilic polymer material shell and a hydrophobic polymer material shell, the microcapsule material of the present invention has the ability to resist the penetration of multiple solvents, good compatibility with specific matrix materials (such as PMMA bone cement), and dispersibility in specific solvents, compared with microcapsules with a single polymer shell.

Description

Technical Field

[0001] The present invention belongs to the technical field of micro-nano material preparation and processing, and specifically relates to a microcapsule and a preparation method and application thereof. Background Art

[0002] Microcapsules, also known as microcapsules, are small particles containing active ingredients or core materials surrounded by a covering layer or shell. After the special core material is microencapsulated, its color, shape, volume, quality, solubility and storage properties will change to a certain extent. Under certain conditions, the core material can be slowly released to play a role.

[0003] For example, impermeable microcapsules in cosmetics must have the following properties: 1) provide long-term and stable protection for the core material during production; 2) will not be destroyed during the production process, but can function or be destroyed during use; 3) be easy to manufacture; and so on.

[0004] Another example is phase change microcapsules, which are phase change materials in microencapsulated form. They are widely used in energy, construction, medical and other fields. In addition to protecting the phase change core material during the production process, phase change microcapsules also need to prevent core material leakage during use, thereby ensuring their stable phase change ability for a long time.

[0005] However, due to the limitations of the preparation process, microcapsules generally have a shell of a single nature, and therefore cannot protect the core material and thus ensure the function of the core material in complex and diverse actual application environments. Summary of the invention

[0006] In order to improve the above technical problems, the present invention provides a microcapsule and a preparation method and application thereof. The microcapsule has a hydrophilic / hydrophobic laminated shell structure, which overcomes the problems of single shell properties and single application environment of general microcapsules. The present invention can obtain microcapsules with resistance to multiple solvents, good dispersion in multiple solvents, and matching the requirements of different application environments by designing the shell composition and structure; and the microcapsule preparation process is simple, has strong universality, and the raw materials used are cheap and easily available, so this type of microcapsule has broad application prospects in the fields of energy, construction, and medical treatment.

[0007] The technical solution of the present invention is as follows:

[0008] A microcapsule, wherein the shell of the microcapsule comprises at least two layers, one layer is a hydrophobic polymer material layer, and the other layer is a hydrophilic polymer material layer.

[0009] According to the present invention, the polymer material located inside the shell layer may be cross-linked or non-cross-linked.

[0010] According to the present invention, the hydrophilic polymer material is polymerized from monomers containing hydrophilic groups, and the hydrophilic groups are, for example, one, two or more of functional groups such as amino, carboxyl, hydroxyl or sulfonic acid groups; the monomers containing hydrophilic groups are, for example, one, two or more selected from (meth)acrylic acid, hydroxyethyl (meth)acrylate, N-methyl (meth)acrylamide, p-styrene sulfonic acid, sodium p-styrene sulfonate, etc.; preferably (meth)acrylic acid.

[0011] According to the present invention, the hydrophobic polymer material is polymerized from monomers containing hydrophobic groups, and the hydrophobic groups are, for example, hydrocarbon groups containing aromatic, ester, ether, amine, amide and the like, or hydrocarbon groups containing double bonds; the monomers containing hydrophobic groups are, for example, selected from acrylate monomers such as methyl (meth)acrylate and ethyl (meth)acrylate, or one, two or more of styrene, acrylonitrile, vinyl pyridine and the like; preferably, methyl (meth)acrylate.

[0012] According to the present invention, the mass ratio of the monomer containing the hydrophilic group to the monomer containing the hydrophobic group is 1-99:99-1.

[0013] According to the present invention, the ratio of the sum of the mass of the monomer containing the hydrophilic group and the monomer containing the hydrophobic group to the mass of the microcapsule core material is (5-95):(95-5), preferably (10-50):(90-50).

[0014] According to the present invention, the microcapsule also includes a core layer, which is located inside the shell layer; the material forming the core layer (i.e., the core material) is selected from alcohol compounds with a carbon number of 4 to 50, organic acid compounds with a carbon number of 4 to 50, alkanes or aromatic hydrocarbon compounds with a carbon number of 6 to 50, or at least one of the esters obtained by reacting the above-mentioned alcohol compounds with a carbon number of 4 to 50 and organic acid compounds with a carbon number of 4 to 50, or selected from water-soluble active ingredients (exemplary including at least one of water-soluble enzymes, fluorescent dyes, photosensitizers, thermosensitizers, etc.).

[0015] The present invention also provides a method for preparing the above microcapsules, the method comprising the following steps:

[0016] (S1) preparing a water-in-oil emulsion or an oil-in-water emulsion including a core material;

[0017] (S2) adding a monomer containing a hydrophobic group or a monomer containing a hydrophilic group, and an initiator to the emulsion of step (S1) to prepare a hydrophobic polymer material layer or a hydrophilic polymer material layer;

[0018] (S3) Further adding a monomer containing a hydrophilic group or a monomer containing a hydrophobic group to the emulsion of step (S2) to prepare the microcapsule.

[0019] According to the present invention, the oil-in-water emulsion or the water-in-oil emulsion is, for example, selected from one of a paraffin-in-water emulsion, a fatty acid (such as myristic acid, stearic acid, lauric acid, etc.)-in-water emulsion, a cyclohexane-in-water emulsion, a toluene-in-water emulsion, and the like; for example, the water in the water-in-oil emulsion contains a water-soluble active ingredient (exemplarily including at least one of a water-soluble enzyme, a fluorescent dye, a photosensitizer, a thermosensitizer, etc.).

[0020] According to the present invention, when the polymer material located inside the shell layer is cross-linked, the cross-linking agent used is selected from one, two or more of ethylene glycol diacrylate, pentaerythritol acrylates, and N,N'-methylenebisacrylamide; preferably N,N'-methylenebisacrylamide and / or ethylene glycol diacrylate.

[0021] According to the present invention, a dispersant or an emulsifier may be added in step (S2) or step (S3), for example, the dispersant is a PVA solution. The emulsifier is, for example, Span-80.

[0022] The present invention also provides an application of the above microcapsules for temperature regulation and energy storage; the microcapsules can be used for temperature regulation and / or energy storage in the fields of construction, medical treatment, etc.

[0023] The present invention provides a bone cement, wherein the filler of the bone cement comprises the microcapsule.

[0024] According to the present invention, the bone cement is poly (meth) acrylate bone cement.

[0025] According to the present invention, the mass percentage of the microcapsules in the bone cement is 10% to 50%, preferably 20% to 40%.

[0026] Beneficial effects of the present invention:

[0027] 1. The microcapsule material of the present invention has the ability to resist the penetration of multiple solvents, good compatibility with specific matrix materials (such as poly (meth) acrylate bone cement, specifically PMMA bone cement), and dispersibility in specific solvents due to the introduction of a composite shell structure of a hydrophilic polymer shell and a hydrophobic polymer shell. Specifically, the lipophilic / hydrophobic laminated shell in the microcapsule can resist the penetration of water, and the hydrophilic shell layer can resist the penetration of some organic solvents. Therefore, the microcapsule can be used in both aqueous environments and some organic solvents, which can prevent the core material from leaking in different solvent systems and prevent the core material from being contaminated by the solvent outside the capsule.

[0028] 2. The preparation method of the microcapsules in the present invention is an interfacial polymerization method. Therefore, the properties of the microcapsules can be achieved by changing the type and composition of the emulsion and adjusting the reaction conditions to regulate the composition and structure of the microcapsules. For example, the shell of the microcapsule can be either a hydrophobic outer layer and a hydrophilic inner layer, or a hydrophilic outer layer and a hydrophobic inner layer.

[0029] 3. Due to the special shell structure of the microcapsule in the present invention, compared with the traditional microcapsule with a single shell property, it is easy to store and use in a variety of different environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0031] Figure 1 This is a scanning electron microscope image of the microcapsule material prepared in Example 1.

[0032] Figure 2 This is a hot polarizing microscope image of the microcapsule material prepared in Example 1.

[0033] Figure 3 The single (left) and multiple (right) temperature scanning curves of differential scanning calorimetry of the microcapsule material in Example 1.

[0034] Figure 4 This is a temperature multiple scanning curve diagram of differential scanning calorimetry of the microcapsule material after immersion in methyl methacrylate in Example 1.

[0035] Figure 5 This is a graph showing the cooling effect of the microcapsule material in Example 1 as a PMMA bone cement filler.

[0036] Figure 6 This is a scanning electron microscope image of the interface of PMMA bone cement composited with microcapsule material in Example 1. DETAILED DESCRIPTION

[0037] [Microcapsules]

[0038] As mentioned above, the present invention provides a microcapsule, wherein the shell of the microcapsule comprises at least two layers, one layer being a hydrophobic polymer material layer, and the other layer being a hydrophilic polymer material layer.

[0039] According to the present invention, the shell layer includes at least two layers, the inner layer located on the surface of the core layer, and the outer layer located on the surface of the inner layer; the inner layer is a hydrophobic polymer material layer, and the outer layer is a hydrophilic polymer material layer; or, the inner layer is a hydrophilic polymer material layer, and the outer layer is a hydrophobic polymer material layer.

[0040] The microcapsules of the present application have a hydrophilic / hydrophobic laminated shell structure, that is, the materials of the inner layer and the outer layer in the shell of the microcapsule are respectively composed of a hydrophilic polymer material and a hydrophobic polymer material, so that the microcapsules can effectively prevent both aqueous solutions and organic solvents from penetrating into the microcapsules, and improve the dispersibility of the microcapsules in different solvent systems, so that the microcapsules have a wider range of applications.

[0041] According to the present invention, the polymer material located inside the shell layer may be cross-linked or non-cross-linked.

[0042] According to the present invention, the hydrophilic polymer material is polymerized from monomers containing hydrophilic groups, and the hydrophilic groups are, for example, one, two or more of functional groups such as amino, carboxyl, hydroxyl or sulfonic acid groups; the monomers containing hydrophilic groups are, for example, one, two or more selected from (meth)acrylic acid, hydroxyethyl (meth)acrylate, N-methyl (meth)acrylamide, p-styrene sulfonic acid, sodium p-styrene sulfonate, etc.; preferably (meth)acrylic acid.

[0043] According to the present invention, the hydrophobic polymer material is polymerized from monomers containing hydrophobic groups, and the hydrophobic groups are, for example, hydrocarbon groups containing aromatic, ester, ether, amine, amide and the like, or hydrocarbon groups containing double bonds; the monomers containing hydrophobic groups are, for example, selected from acrylate monomers such as methyl (meth)acrylate and ethyl (meth)acrylate, or one, two or more of styrene, acrylonitrile, vinyl pyridine and the like; preferably, methyl (meth)acrylate.

[0044] According to the present invention, the mass ratio of the monomer containing a hydrophilic group to the monomer containing a hydrophobic group, or the ratio of the sum of the mass of the monomer containing a hydrophilic group and a cross-linking agent to the mass of the monomer containing a hydrophobic group is (1-99): (99-1). For example, 1:99, 10:90, 20:80, 30:70, 40:60, 50:50, 60:40, 70:30, 80:20, 90:10, 99:1, or any point value within the range of any two combinations. The solvent resistance of the microcapsule shell is affected by the mass ratio of the monomer containing a hydrophilic group to the monomer containing a hydrophobic group.

[0045] In the present invention, the solvent resistance of the shell of the microcapsule is affected by the thickness of the polymer shell, and the shell thickness can be controlled by the ratio of the sum of the mass of the monomer containing hydrophilic groups and the monomer containing hydrophobic groups to the mass of the microcapsule core material.

[0046] According to the present invention, the ratio of the sum of the masses of the monomer containing a hydrophilic group and the monomer containing a hydrophobic group to the mass of the microcapsule core material, or the ratio of the sum of the masses of the monomer containing a hydrophilic group, the monomer containing a hydrophobic group and the cross-linking agent to the mass of the microcapsule core material is (5-95):(95-5), preferably (10-50):(90-50), for example, it can be 5:95, 10:90, 20:80, 30:70, 40:60, 50:50, 60:40, 70:30, 80:20, 90:10, 95:5, or any point value within the range of any two combinations.

[0047] According to the present invention, the microcapsule also includes a core layer, which is located inside the shell layer; the material forming the core layer (i.e., the core material) is selected from alcohol compounds with a carbon number of 4 to 50, organic acid compounds with a carbon number of 4 to 50, alkanes or aromatic hydrocarbon compounds with a carbon number of 6 to 50, or at least one of the esters obtained by reacting the above-mentioned alcohol compounds with a carbon number of 4 to 50 and organic acid compounds with a carbon number of 4 to 50, or selected from water-soluble active ingredients (exemplary including at least one of water-soluble enzymes, fluorescent dyes, photosensitizers, thermosensitizers, etc.).

[0048] According to the present invention, when the material forming the core layer (i.e., the core material) is selected from alcohol compounds with 4 to 50 carbon atoms, organic acid compounds with 4 to 50 carbon atoms, alkanes or aromatic hydrocarbon compounds with 6 to 50 carbon atoms, or at least one of esters obtained by reacting the above alcohol compounds with 4 to 50 carbon atoms with organic acid compounds with 4 to 50 carbon atoms, the microcapsules can be prepared by oil-in-water emulsion or water-in-oil emulsion. When the material forming the core layer (i.e., the core material) is selected from water-soluble active ingredients, the microcapsules can be prepared by water-in-oil emulsion.

[0049] According to the present invention, the alcohol compound is selected from at least one of alkyl alcohols having 4 to 50 carbon atoms, such as tetradecanol and hexadecanol.

[0050] According to the present invention, the organic acid compound is at least one of alkyl acids having 4 to 50 carbon atoms, such as lauric acid, myristic acid, stearic acid and the like.

[0051] According to the present invention, the alkane compound having 6 to 50 carbon atoms is selected from n-hexane, n-dodecane, paraffin, octadecane or n-eicosane. The melting point of the paraffin is, for example, 10°C to 90°C.

[0052] According to the present invention, the aromatic hydrocarbon compound having 6 to 50 carbon atoms is, for example, toluene.

[0053] According to the invention, the ester is for example chosen from butyl stearate.

[0054] According to the present invention, the water-soluble active ingredient is, for example, at least one selected from water-soluble enzymes, fluorescent dyes, photosensitizers, thermosensitizers, etc., and an exemplary one may be a fluoroboron dipyrrole anticancer photosensitizer.

[0055] [Preparation of microcapsules]

[0056] The present invention also provides a method for preparing the above microcapsules, the method comprising the following steps:

[0057] (S1) preparing a water-in-oil emulsion or an oil-in-water emulsion including a core material;

[0058] (S2) adding a monomer containing a hydrophobic group or a monomer containing a hydrophilic group, and an initiator to the emulsion of step (S1) to prepare a hydrophobic polymer material layer or a hydrophilic polymer material layer;

[0059] (S3) Further adding a monomer containing a hydrophilic group or a monomer containing a hydrophobic group to the emulsion of step (S2) to prepare the microcapsule.

[0060] As an embodiment of the present invention, the method for preparing the microcapsules comprises the following steps:

[0061] (S1) preparing a water-in-oil emulsion including a core material;

[0062] (S2) adding a monomer containing a hydrophobic group and an initiator to the emulsion of step (S1) to prepare a hydrophobic polymer material layer;

[0063] (S3) Further adding a monomer containing a hydrophilic group to the emulsion of step (S2) to prepare microcapsules, wherein the outer layer of the microcapsules is hydrophilic and the inner layer is hydrophobic.

[0064] Illustratively, in the water-in-oil emulsion of step (S1), if the core material is selected from water-soluble active ingredients, it is included in the water phase; if other water-insoluble substances are selected, they are included in the oil phase.

[0065] As an embodiment of the present invention, the method for preparing the microcapsules comprises the following steps:

[0066] (S1) preparing an oil-in-water emulsion including a core material;

[0067] (S2) adding a monomer containing a hydrophilic group and an initiator to the emulsion of step (S1) to prepare a hydrophilic polymer material layer;

[0068] (S3) Further adding a monomer containing a hydrophobic group to the emulsion of step (S2) to prepare microcapsules, wherein the outer layer of the microcapsules is hydrophobic and the inner layer is hydrophilic.

[0069] Illustratively, in the oil-in-water emulsion of step (S1), the core material is selected from other substances defined above except the water-soluble active ingredient, and is included in the oil phase.

[0070] According to the present invention, in step (S2), the initiator may be a free radical polymerization thermal initiator, a free radical polymerization photoinitiator, or a redox initiation system.

[0071] The free radical polymerization thermal initiator is selected from peroxides, persulfides or azo compounds, for example, at least one selected from potassium persulfate, ammonium persulfate, benzoyl peroxide, azobisisobutyronitrile and the like.

[0072] The free radical polymerization photoinitiator is, for example, at least one selected from 2,4,6-(trimethylbenzoyl)-diphenylphosphine oxide, 2,4,6-trimethylbenzoyl ethyl phosphate, benzoin dimethyl ether, and the like.

[0073] Among them, in the redox initiation system, for example, the oxidant is selected from one of ammonium persulfate, potassium persulfate, benzoyl peroxide, azobisisobutyronitrile, etc.: the reducing agent is selected from one of divalent iron ions, sodium sulfite, cyclopentane acid metal salts (the metal is such as cobalt, manganese, vanadium or iron, etc.), or tertiary amine compounds, such as N,N'-dimethylaniline or thiol, etc.

[0074] Among them, since the weak light transmittance of the emulsion reduces the efficiency of the photoinitiated polymerization reaction, free radical polymerization thermal initiators and redox initiation systems are preferred. For example, when the shell layer is hydrophilic on the inner layer and hydrophobic on the outer layer, the initiator is preferably an oil-soluble thermal initiator benzoyl peroxide and / or a redox initiation system of benzoyl peroxide-N,N'-dimethylaniline; when the shell layer is hydrophobic on the inner layer and hydrophilic on the outer layer, a water-soluble thermal initiator ammonium persulfate and / or a redox initiation system of ammonium persulfate and sodium sulfite is preferred.

[0075] Among them, the mass percentage of the sum of the mass of the free radical polymerization thermal initiator, the monomer containing the hydrophobic group and the monomer containing the hydrophilic group is 0.1% to 10%. Considering that there must be enough free radicals in the reaction process to ensure the sequential formation of the multi-layer polymer shell layer, it is preferably 2% to 6%, and more preferably 4%.

[0076] Among them, when the initiator used is a redox initiation system, the mass percentage of the sum of the mass of the oxidant and the monomer containing a hydrophobic group and the monomer containing a hydrophilic group in the redox initiation system is 0.1% to 10%. Considering that there must be enough free radicals in the reaction process to ensure the sequential formation of multi-layer polymer shells, it is preferably 2% to 6%, more preferably 4.8%. The molar ratio of the oxidant to the reductant is 1:2 to 5, preferably 1:4.25.

[0077] Specifically, the oil-in-water emulsion or water-in-oil emulsion is, for example, selected from one of a paraffin-in-water emulsion, a fatty acid (such as myristic acid, stearic acid, lauric acid, etc.) in water emulsion, a cyclohexane-in-water emulsion, a toluene-in-water emulsion, and the like; for example, the water in the water-in-oil emulsion contains a water-soluble active ingredient (exemplarily including at least one of a water-soluble enzyme, a fluorescent dye, a photosensitizer, a thermosensitizer, etc.).

[0078] According to the present invention, the dispersed phase volume fraction of the emulsion is 1%-50%, for example, 10%-30% is selected in the example, for example, it can be 1%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, or any point value in the range of any combination of two.

[0079] According to one embodiment of the present invention, the microcapsules can be prepared in an oil-in-water emulsion, for example, the monomer containing a hydrophilic group is methacrylic acid, the crosslinking agent is N,N'-methylenebisacrylamide, the oil-in-water emulsion is a lauric acid-in-water emulsion, and the monomer containing a hydrophobic group is methyl methacrylate. The specific preparation method is: first, thermally or redox-initiated polymerization of methacrylic acid is performed on the surface of the lauric acid-in-water emulsion droplets to generate a hydrophilic polymer material layer, then methyl methacrylate and crosslinking agent ethylene glycol diacrylate are slowly added dropwise to the emulsion, and polymerization is continued on the hydrophilic polymer material layer to generate a hydrophobic polymer material layer, and finally a microcapsule having a laminated shell structure with an inner hydrophilic layer and an outer hydrophobic layer is formed.

[0080] According to one embodiment of the present invention, the microcapsules are prepared in an oil-in-water emulsion, for example, the monomer containing a hydrophobic group is methyl methacrylate, the crosslinking agent is ethylene glycol diacrylate, the oil-in-water emulsion is a cyclohexane-in-water emulsion, and the monomer containing a hydrophilic group is methacrylic acid. The specific preparation method is: thermal initiation or redox initiation polymerization of methyl methacrylate at the interface of the cyclohexane-in-water emulsion to generate a hydrophobic polymer material layer, then methacrylic acid and a crosslinking agent N, N'-methylenebisacrylamide are slowly added dropwise to the above emulsion, and continue to polymerize on the hydrophobic polymer material layer to generate a hydrophilic polymer material layer, and finally form a microcapsule with a laminated shell structure with an inner hydrophobic layer and an outer hydrophilic layer.

[0081] According to one embodiment of the present invention, the microcapsules are prepared in an oil-in-water emulsion, for example, the monomer containing a hydrophobic group is methyl methacrylate, the crosslinking agent is ethylene glycol diacrylate, the oil-in-water emulsion is a cyclohexane-in-water emulsion, and the water includes a water-soluble active ingredient (the water-soluble active ingredient can be, for example, a water-soluble fluoroboron dipyrrole anticancer photosensitizer), and the monomer containing a hydrophilic group is methacrylic acid. The specific preparation method is: thermal initiation or redox initiation of methyl methacrylate polymerization at the interface of the cyclohexane-in-water emulsion (the water includes a water-soluble active ingredient) to generate a hydrophobic polymer material layer, then methacrylic acid and a crosslinking agent N, N'-methylenebisacrylamide are slowly added dropwise to the above emulsion, and polymerization continues on the hydrophobic polymer material layer to generate a layer of hydrophilic polymer material layer, and finally a microcapsule having a laminated shell structure with an inner hydrophobic layer and an outer hydrophilic layer is formed.

[0082] According to the present invention, when the polymer material located inside the layer is cross-linked, the cross-linking agent used is selected from one, two or more of ethylene glycol diacrylate, pentaerythritol acrylates, and N,N'-methylenebisacrylamide; preferably N,N'-methylenebisacrylamide and / or ethylene glycol diacrylate.

[0083] According to the present invention, the mass ratio of the crosslinking agent to the monomer containing a hydrophilic group and / or the monomer containing a hydrophobic group is (0-30):100, and in order for the capsule polymer shell to have the ability to resist solvent swelling, it is preferably (10-25):100; in addition. In order to ensure that the capsule shell has sufficient mechanical strength, the crosslinking agent is, for example, selected from N,N'-methylenebisacrylamide, and the mass ratio thereof to the monomer containing a hydrophilic group is (20-25):100; or, the crosslinking agent is, for example, selected from ethylene glycol diacrylate, and the mass ratio thereof to the monomer containing a hydrophobic group is (20-25):100.

[0084] According to the present invention, a dispersant or an emulsifier may be added in step (S2) and / or step (S3), for example, the dispersant is a PVA solution, preferably a PVA aqueous solution, the mass fraction of the PVA aqueous solution is 5-10%, preferably 10%. The emulsifier is, for example, Span-80, and its concentration is, for example, 0.01-0.04 g / mL, illustratively, 0.01, 0.02, 0.03 or 0.04 g / mL.

[0085] According to the present invention, in step (S3), the monomer containing a hydrophilic group or the monomer containing a hydrophobic group can be added in a step-by-step manner, for example, in two steps. For example, in the first step, a portion of the monomer containing a hydrophilic group or the monomer containing a hydrophobic group is first added to the emulsion of step (S2), and in the second step, the remaining portion is added.

[0086] Preferably, the mass ratio of the monomer containing a hydrophilic group or the monomer containing a hydrophobic group added in the first step to the monomer added in the second step is (2-6):1, illustratively 2:1, 3:1, 4:1, 5:1 or 6:1.

[0087] According to the present invention, the reaction is carried out under the protection of an inert gas, such as nitrogen.

[0088] According to the present invention, exemplarily, when the initiator is a free radical polymerization thermal initiator, the reaction system is a thermally initiated reaction, which refers to a reaction initiated under heating conditions. The initiation temperature (i.e., reaction temperature) can be 40 to 100°C, preferably 60 to 80°C, depending on the type of initiator, for example, it can be 40°C, 50°C, 60°C, 70°C, 80°C, 90°C, 100°C or any point value within the range of any combination of any two.

[0089] According to the present invention, exemplarily, when the initiator is a redox initiation system, the reaction system is a redox initiation reaction, which refers to two substances with oxidizing and reducing properties generating free radicals through a redox reaction, thereby initiating monomer polymerization. The advantages of the redox initiation system are that the polymerization is initiated quickly and can be initiated at a lower temperature. For example, in an oil-in-water emulsion, a redox initiation system is used, the oxidant is benzoyl peroxide, and the reducing agent is N,N'-dimethylaniline; in an oil-in-water emulsion, a redox initiation system is used, the oxidant is sodium persulfate, and the reducing agent is sodium sulfite.

[0090] According to the present invention, when the initiator is a free radical polymerization photoinitiator, the power of the ultraviolet lamp initiating under ultraviolet light is 1 to 3 kW, illustratively 1.0, 1.2, 1.4, 1.6, 1.8, 2.0, 2.5 or 3.0 kW.

[0091] According to the present invention, the reaction time for forming the inner layer of the microcapsule shell can be 5 to 40 minutes, exemplarily 5, 10, 20, 30 or 40 minutes. If the time is too long, the free radicals will disappear, resulting in the inability of subsequent polymerization. If the time is too short, the inner layer has not yet been formed, resulting in the inability to form a laminated shell.

[0092] According to the present invention, the reaction time for forming the outer layer of the microcapsule shell is 5 to 10 hours, for example, 5, 6, 7, 8, 9 or 10 hours.

[0093] As an embodiment of the present invention, the preparation method of the microcapsule is:

[0094] (S1) preparing an oil-in-water emulsion, wherein the oil phase includes a core material;

[0095] (S2) adding a monomer containing a hydrophilic group and an initiator to the emulsion to prepare a hydrophilic polymer material layer;

[0096] (S3) Continue to drop a portion of the monomer containing the hydrophobic group into step (S2), and then add the remaining portion of the monomer containing the hydrophobic group to prepare microcapsules, wherein the microcapsules have a structure in which the outer layer is hydrophobic and the inner layer is hydrophilic.

[0097] As an embodiment of the present invention, the preparation method of the microcapsule is:

[0098] (S1) preparing a water-in-oil emulsion, wherein the water phase includes a core material selected from water-soluble active ingredients, or the oil phase includes a core material selected from water-insoluble substances;

[0099] (S2) adding a monomer containing a hydrophobic group and an initiator to the emulsion to prepare a hydrophobic polymer material layer;

[0100] (S3) adding a portion of the monomer containing a hydrophilic group to step (S2), and then adding the remaining portion of the monomer containing a hydrophilic group to prepare a microcapsule having a structure of a hydrophilic outer layer and a hydrophobic inner layer.

[0101] As an embodiment of the present invention, the preparation method of the microcapsule is:

[0102] (S1) preparing a water-in-oil emulsion, wherein the water phase includes a water-soluble active ingredient;

[0103] (S2) adding a monomer containing a hydrophobic group and an initiator to the emulsion to prepare a hydrophobic polymer material layer;

[0104] (S3) adding a portion of the monomer containing a hydrophilic group to step (S2), and then adding the remaining portion of the monomer containing a hydrophilic group to prepare a microcapsule having a structure of an outer hydrophilic layer and an inner hydrophobic layer;

[0105] [Application of microcapsules]

[0106] The present invention also provides an application of the microcapsule for temperature regulation and / or energy storage, for example, for temperature regulation and / or energy storage in the fields of construction, medical treatment, etc.

[0107] The present invention provides a bone cement, wherein the filler of the bone cement comprises the microcapsule.

[0108] According to the present invention, the bone cement is poly(meth)acrylate bone cement, specifically PMMA bone cement.

[0109] In the present invention, the introduction of the microcapsules can cool the bone cement.

[0110] According to the present invention, the mass percentage of the microcapsules in the bone cement is 10% to 50%, preferably 20% to 40%; for example, it can be 10%, 20%, 30%, 40%, or 50%.

[0111] The main body of the bone cement is composed of polymethyl methacrylate powder and methyl methacrylate monomer liquid. When used, the ratio of polymethyl methacrylate powder to methyl methacrylate monomer liquid is 1 to 3 g / ml, exemplarily 1, 1.5, 2, 2.5 or 3 g / ml.

[0112] The embodiments of the present application will be described in detail below in conjunction with the examples, but it will be appreciated by those skilled in the art that the following examples are only used to illustrate the present application and should not be considered as limiting the scope of the present application. In the examples, if specific conditions are not specified, they are carried out according to normal conditions or the conditions recommended by the manufacturer. If the manufacturer is not specified for the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0113] Example 1

[0114] The present invention provides a microcapsule material having a hydrophilic / hydrophobic laminated shell structure and a preparation method thereof, which comprises the following steps:

[0115] The embodiment of the present application uses a lauric acid-in-water emulsion, wherein the volume fraction of the dispersed phase is 10%.

[0116] Solution A was prepared by dissolving 0.1g benzoyl peroxide in 6g lauric acid at 60℃. Solution B was prepared by mechanically stirring and mixing 15ml of 10% PVA aqueous solution and 50ml of deionized water in a three-necked flask, preheating at 60℃ and passing nitrogen gas for deoxygenation during the whole process. Solution C was prepared by mechanically shaking 0.2g N,N'-methylenebisacrylamide and 0.8g methacrylic acid. 1g methyl methacrylate was used as monomer D. 0.25g ethylene glycol dimethyl acrylate and 0.25g methyl methacrylate were prepared to form a uniform solution E. Solution A and solution C were added to the preheated solution B, mechanically stirred at 1000rpm for 10 minutes, then heated to 85℃ and the stirring rate was reduced to 400rpm for polymerization for 10 minutes. Monomer D was added dropwise over 5 minutes, and solution E was added dropwise over 2.5 minutes after another 10 minutes. The stirring rate was reduced to 100rpm and the reaction was carried out for 6 hours. The resulting solution after the reaction was centrifuged at 7500 rpm for 2 minutes, the supernatant was discarded, and the solution was washed three times with deionized water. The separated product was dispersed in deionized water and freeze-dried to obtain a white powder product, namely, microcapsules.

[0117] The microscopic morphology of the microcapsule product was observed using a field emission scanning electron microscope combined with a thermal polarizing microscope. Figure 1, which is a scanning electron microscope image of the microcapsule material prepared in Example 1, Figure 1 The microcapsules are spherical, with an average size of 20 μm and are basically uniform in size.

[0118] Figure 2 This is a hot polarizing microscope image of the microcapsule material prepared in Example 1. The hot polarizing microscope shows that there is a crystalline phase inside the capsule, that is, the presence of bright spots of the crystalline phase in the image proves that the shell layer successfully encapsulates lauric acid.

[0119] Figure 3 The temperature scanning curves of the differential scanning calorimetry of the microcapsule material in Example 1 after a single time (left) and after 5 cycles (right) are shown. The high phase change enthalpy indicates that the capsule has a higher core material content. During multiple heating-cooling cycles, the curves basically overlap, indicating that the microcapsule has a stable phase change ability. Figure 3 The phase transition temperature and phase transition enthalpy of the microcapsules are 44.2℃ and 117.6J / g respectively (see Figure 3 ), by comparing the phase change enthalpy of the microcapsules with that of pure lauric acid, it was found that the mass fraction of lauric acid in the core material of the product was 64.3%, and the microcapsules could still maintain their phase change ability unchanged after undergoing multiple hot and cold cycles.

[0120] Figure 4 This is the temperature multiple scanning curve of differential scanning calorimetry of the microcapsule material after immersion in methyl methacrylate in Example 1; the microcapsule material after immersion in methyl methacrylate still has a phase change enthalpy close to that of the original microcapsule, indicating that the microcapsule has the ability to resist methyl methacrylate penetration.

[0121] Since lauric acid has the ability to change phase, the content of lauric acid in the product is proportional to its phase change enthalpy, and lauric acid is soluble in organic solvents such as ethanol, acetone, and methyl methacrylate. If the microcapsules are not resistant to organic solvent penetration, the lauric acid in the microcapsules will leak out. Therefore, the solvent resistance of the product can be evaluated by measuring the phase change enthalpy of the product after soaking in different solvents by differential scanning calorimetry and comparing it with the phase change enthalpy of the product before soaking. The differential scanning calorimetry results of the product after the microcapsules were soaked in methyl methacrylate and the soaking liquid was removed showed that it still had a phase change enthalpy of 104.9 J / g (see Figure 4 ), since the microcapsules are prepared in an aqueous solution environment, it is proved that the microcapsules can resist the penetration of water and methyl methacrylate (PMMA bone cement is composed of polymethyl methacrylate powder and methyl methacrylate monomer liquid, and the two are mixed in a ratio of 2g / ml when used).

[0122] After mixing this product with commercially available PMMA bone cement powder, the maximum exothermic temperature of the bone cement during curing was measured. The test results are as follows: Figure 5 , Figure 5The curves are the cooling effect of microcapsule materials as PMMA bone cement fillers, where Curve-PMMA is the solidification temperature curve of pure PMMA bone cement over time, Curve-PMMA20, Curve-PMMA30, and Curve-PMMA40 are composite PMMA bone cements containing 20%, 30%, and 40% microcapsules by mass, respectively; the results show that with the increase of the amount of microcapsules in the composite bone cement, the maximum exothermic temperature of the bone cement decreases, and when the mass of the microcapsules accounts for 40% of the mass of the composite bone cement, the best cooling effect can be achieved, and the maximum exothermic temperature of the bone cement can be reduced to 44.5°C (near the phase transition temperature of lauric acid, see Figure 5 ).

[0123] The scanning electron microscopy images of the composite bone cement cross section showed that the microcapsules were evenly dispersed in the bone cement matrix, and the lauric acid crystals were still retained in the microcapsule shell (see Figure 6 , Figure 6 The figure is a scanning electron microscope image of the interface of PMMA bone cement composited with microcapsule material in Example 1, in which the microcapsules are uniformly dispersed in the bone cement matrix, and the lauric acid crystals are still retained in the microcapsule shell, proving that the microcapsules can be used in a system with methyl methacrylate as a solvent. It is proved that the microcapsules can resist the penetration of methyl methacrylate monomer into the microcapsules when mixed with bone cement, thereby protecting the structure and phase change function of the microcapsules (lauric acid and polymethyl methacrylate can both dissolve or swell in methyl methacrylate).

[0124] Example 2

[0125] The present application provides a microcapsule material having a hydrophilic / hydrophobic laminated shell structure and a preparation method thereof, which comprises the following steps:

[0126] The present application example uses lauric acid in water emulsion, and the volume fraction of the dispersed phase is 20%.

[0127] Solution A was prepared by dissolving 0.2g of benzoyl peroxide in 12g of lauric acid at 60°C. 15ml of 10% PVA aqueous solution and 50ml of deionized water were mechanically stirred and mixed in a three-necked flask. At the same time, solution B was prepared by preheating at 60°C and nitrogen was passed through the whole process for deoxygenation. 0.4g of N,N-methylenebisacrylamide and 1.6g of methacrylic acid were mechanically shaken to prepare a clear and uniform solution C. 2g of methyl methacrylate was used as monomer D. 0.5g of ethylene glycol dimethyl acrylate and 0.5g of methyl methacrylate were prepared to prepare a uniform solution E. The prepared solution A and solution C were added to the preheated solution B, mechanically stirred at 1000rpm for 10 minutes, then heated to 85°C and the stirring rate was reduced to 400rpm for polymerization for 10 minutes. Monomer D was added dropwise over 5 minutes, and solution E was added dropwise over 2.5 minutes after another 10 minutes. The stirring rate was reduced to 100rpm for reaction for 6 hours. The resulting solution after the reaction was centrifuged at 7500 rpm for 2 minutes, the supernatant was discarded, and the solution was washed three times with deionized water. The separated product was dispersed in deionized water and freeze-dried to obtain a white powder product, namely, microcapsules.

[0128] A complete core-shell structure of polymer-encapsulated lauric acid can be formed, and the microcapsules can resist the penetration of water and organic solvents (such as ethanol, acetone or methyl methacrylate, etc.).

[0129] Example 3

[0130] The present invention provides a microcapsule material having a hydrophilic / hydrophobic laminated shell structure and a preparation method thereof, which comprises the following steps:

[0131] The present embodiment uses lauric acid in water emulsion, and the volume fraction of the dispersed phase is 30%.

[0132] Solution A was prepared by dissolving 0.3g of benzoyl peroxide in 18g of lauric acid at 60°C. 15ml of 10% PVA aqueous solution and 50ml of deionized water were mechanically stirred and mixed in a three-necked flask, and preheated at 60°C and nitrogen was passed through the whole process to deoxygenate to prepare solution B. 0.6g of N, N'-methylenebisacrylamide and 2.4g of methacrylic acid were mechanically shaken to prepare a clear and uniform solution C. 3g of methyl methacrylate was used as monomer D. 7.5g of ethylene glycol dimethyl acrylate and 0.75g of methyl methacrylate were prepared to prepare a uniform solution E. The prepared solution A and solution C were added to the preheated solution B, mechanically stirred at 1000rpm for 10 minutes, then heated to 85°C and the stirring rate was reduced to 400rpm for polymerization for 10 minutes. Monomer D was added dropwise over 5 minutes, and solution E was added dropwise over 2.5 minutes after another 10 minutes. The stirring rate was reduced to 100rpm and the reaction was carried out for 6 hours. The resulting solution after the reaction was centrifuged at 7500 rpm for 2 minutes, the supernatant was discarded, and the solution was washed three times with deionized water. The separated product was dispersed in deionized water and freeze-dried to obtain a white powder product, namely, microcapsules.

[0133] A complete core-shell structure of polymer-encapsulated lauric acid can be formed, and the microcapsules can resist the penetration of water and organic solvents (such as ethanol, acetone or methyl methacrylate, etc.).

[0134] Example 4

[0135] The present invention provides a microcapsule material having a hydrophilic / hydrophobic laminated shell structure and a preparation method thereof, which comprises the following steps:

[0136] The present embodiment uses lauric acid in water emulsion, and the volume fraction of the dispersed phase is 40%.

[0137] Solution A was prepared by dissolving 0.4g of benzoyl peroxide in 24g of lauric acid at 60°C. 15ml of 10% PVA aqueous solution and 50ml of deionized water were mechanically stirred and mixed in a three-necked flask, and preheated at 60°C and nitrogen was passed through the whole process to deoxygenate to prepare solution B. 0.8g of N, N'-methylenebisacrylamide and 3.2g of methacrylic acid were mechanically shaken to prepare a clear and uniform solution C. 4g of methyl methacrylate was used as monomer D, and 1g of ethylene glycol dimethyl acrylate and 1g of methyl methacrylate were prepared to prepare a uniform solution E. The prepared solution A and solution C were added to the preheated solution B, mechanically stirred at 1000rpm for 10 minutes, then heated to 85°C and the stirring rate was reduced to 400rpm for polymerization for 10 minutes. Monomer D was added dropwise over 5 minutes, and solution E was added dropwise over 2.5 minutes after another 10 minutes. The stirring rate was reduced to 100rpm and the reaction was carried out for 6 hours. The resulting solution after the reaction was centrifuged at 7500 rpm for 2 minutes, the supernatant was discarded, and the solution was washed three times with deionized water. The separated product was dispersed in deionized water and freeze-dried to obtain a white powder product, namely, microcapsules.

[0138] A complete core-shell structure of polymer-coated lauric acid can be formed, but the microcapsules are of different sizes, secondary particles are generated, and the microcapsules can resist the penetration of both water and some organic solvents (such as ethanol, acetone or methyl methacrylate, etc.).

[0139] Example 5

[0140] The present invention provides a microcapsule material having a hydrophilic / hydrophobic laminated shell structure and a preparation method thereof, which comprises the following steps:

[0141] The present embodiment uses lauric acid in water emulsion, and the volume fraction of the dispersed phase is 50%.

[0142] Solution A was prepared by dissolving 0.5g of benzoyl peroxide in 30g of lauric acid at 60°C. 15ml of 10% PVA aqueous solution and 50ml of deionized water were mechanically stirred and mixed in a three-necked flask, and preheated at 60°C and nitrogen was passed through the whole process to deoxygenate to prepare solution B. 1g of N, N'-methylenebisacrylamide and 4g of methacrylic acid were mechanically shaken to prepare a clear and uniform solution C. 5g of methyl methacrylate was used as monomer D. 1.2g of ethylene glycol dimethyl acrylate and 1.2g of methyl methacrylate were prepared to prepare a uniform solution E. The prepared solution A and solution C were added to the preheated solution B, mechanically stirred at 1000rpm for 10 minutes, then heated to 85°C and the stirring rate was reduced to 400rpm for polymerization for 10 minutes. Monomer D was added dropwise over 5 minutes, and solution E was added dropwise over 2.5 minutes after another 10 minutes. The stirring rate was reduced to 100rpm and the reaction was carried out for 6 hours. The resulting solution after the reaction was centrifuged at 7500 rpm for 2 minutes, the supernatant was discarded, and the solution was washed three times with deionized water. The separated product was dispersed in deionized water and freeze-dried to obtain a white powder product, namely, microcapsules.

[0143] Particles with a core-shell structure are generated, but a large number of agglomerates and secondary particles are generated, and they are not easy to disperse in water and some organic solvents (such as ethanol, acetone or methyl methacrylate, etc.).

[0144] Example 6

[0145] The present invention provides a microcapsule material having a hydrophilic / hydrophobic laminated shell structure and a preparation method thereof, which comprises the following steps:

[0146] The present embodiment uses lauric acid in water emulsion and adopts oxidation-reduction system to initiate polymerization.

[0147] Solution A was prepared by dissolving 0.1 g of benzoyl peroxide in 6 g of lauric acid at 60° C., 15 ml of a 10% PVA aqueous solution and 50 ml of deionized water were mechanically stirred and mixed in a three-necked flask, and preheated at 60° C. and nitrogen was passed through the entire process to deoxygenate to prepare solution B, 0.2 g of N,N-methylenebisacrylamide and 0.8 g of methacrylic acid were mechanically shaken to prepare a clear and uniform solution C, 1 g of methyl methacrylate was used as monomer D, and 0.25 g of ethylene glycol dimethyl acrylate and 0.25 g of methyl methacrylate were prepared to prepare a uniform solution E. Add the prepared solution A and solution C to the preheated solution B, stir mechanically at 1000rpm for 10 minutes, add 200mg N,N'-dimethylaniline after the temperature drops to room temperature, reduce the stirring rate to 400rpm and polymerize for 10 minutes, add monomer D dropwise over 5 minutes, and then add solution E dropwise over 2.5 minutes after 10 minutes, reduce the stirring rate to 100rpm and react for 6 hours. Centrifuge the resulting solution at 7500rpm for 2 minutes, discard the clear liquid and wash with deionized water three times, and disperse the separated product in deionized water and freeze-dry to obtain a white powdery product, i.e., microcapsules.

[0148] The microcapsule can resist the penetration of water and can resist the penetration of organic solvents (such as ethanol, acetone or methyl methacrylate, etc.).

[0149] Example 7

[0150] The present invention provides a microcapsule material having a hydrophilic / hydrophobic laminated shell structure and a preparation method thereof, which comprises the following steps:

[0151] The embodiment of the present application uses lauric acid in water emulsion, and the mass ratio of the monomer containing hydrophilic group to the monomer containing hydrophobic group is 10%:90%.

[0152] Solution A was prepared by dissolving 0.1g of benzoyl peroxide in 6.5g of lauric acid at 60°C. 15ml of 10% PVA aqueous solution and 50ml of deionized water were mechanically stirred and mixed in a three-necked flask. At the same time, solution B was prepared by preheating at 60°C and nitrogen was passed through the whole process for deoxygenation. 0.05g of N,N'-methylenebisacrylamide and 0.2g of methacrylic acid were mechanically shaken to prepare a clear and uniform solution C. 1.5g of methyl methacrylate was used as monomer D. 0.375g of ethylene glycol dimethyl acrylate and 0.375g of methyl methacrylate were prepared to prepare a uniform solution E. The prepared solution A and solution C were added to the preheated solution B, mechanically stirred at 1000rpm for 10 minutes, then heated to 85°C and the stirring rate was reduced to 400rpm for polymerization for 10 minutes. Monomer D was added dropwise over 5 minutes, and solution E was added dropwise over 2.5 minutes after another 10 minutes. The stirring rate was reduced to 100rpm for reaction for 6 hours. The resulting solution after the reaction was centrifuged at 7500 rpm for 2 minutes, the supernatant was discarded, and the solution was washed three times with deionized water. The separated product was dispersed in deionized water and freeze-dried to obtain a white powder product, namely, microcapsules.

[0153] The microcapsule can resist the penetration of water, but can hardly resist the penetration of organic solvents (such as ethanol, acetone or methyl methacrylate).

[0154] Example 8

[0155] The present invention provides a microcapsule material having a hydrophilic / hydrophobic laminated shell structure and a preparation method thereof, which comprises the following steps:

[0156] The embodiment of the present application uses lauric acid in water emulsion, and the mass ratio of the monomer containing hydrophilic group to the monomer containing hydrophobic group is 20%:80%.

[0157] Solution A was prepared by dissolving 0.1g of benzoyl peroxide in 6.5g of lauric acid at 60°C. 15ml of 10% PVA aqueous solution and 50ml of deionized water were mechanically stirred and mixed in a three-necked flask, and preheated at 60°C and nitrogen was passed through the whole process to deoxygenate to prepare solution B. 0.125g of N, N'-methylenebisacrylamide and 0.375g of methacrylic acid were mechanically shaken to prepare a clear and uniform solution C. 1.333g of methyl methacrylate was used as monomer D. 0.333g of ethylene glycol dimethyl acrylate and 0.333g of methyl methacrylate were prepared to prepare a uniform solution E. The prepared solution A and solution C were added to the preheated solution B, mechanically stirred at 1000rpm for 10 minutes, then heated to 85°C and the stirring rate was reduced to 400rpm for polymerization for 10 minutes. Monomer D was added dropwise over 5 minutes, and solution E was added dropwise over 2.5 minutes after another 10 minutes. The stirring rate was reduced to 100rpm and the reaction was carried out for 6 hours. The resulting solution after the reaction was centrifuged at 7500 rpm for 2 minutes, the supernatant was discarded, and the solution was washed three times with deionized water. The separated product was dispersed in deionized water and freeze-dried to obtain a white powder product, namely, microcapsules.

[0158] The microcapsule can resist the penetration of water, but can hardly resist the penetration of organic solvents (such as ethanol, acetone or methyl methacrylate).

[0159] Example 9

[0160] The present invention provides a microcapsule material having a hydrophilic / hydrophobic laminated shell structure and a preparation method thereof, which comprises the following steps:

[0161] The embodiment of the present application uses lauric acid in water emulsion, and the mass ratio of the monomer containing hydrophilic group to the monomer containing hydrophobic group is 70%:30%.

[0162] Solution A was prepared by dissolving 0.1g of benzoyl peroxide in 6.5g of lauric acid at 60°C. 15ml of 10% PVA aqueous solution and 50ml of deionized water were mechanically stirred and mixed in a three-necked flask, and preheated at 60°C and nitrogen was passed through the whole process to deoxygenate to prepare solution B. 0.188g of N, N'-methylenebisacrylamide and 0.563g of methacrylic acid were mechanically shaken to prepare a clear and uniform solution C. 1.167g of methyl methacrylate was used as monomer D. 0.292g of ethylene glycol dimethyl acrylate and 0.292g of methyl methacrylate were prepared to prepare a uniform solution E. The prepared solution A and solution C were added to the preheated solution B, mechanically stirred at 1000rpm for 10 minutes, then heated to 85°C and the stirring rate was reduced to 400rpm for polymerization for 10 minutes. Monomer D was added dropwise over 5 minutes, and solution E was added dropwise over 2.5 minutes after another 10 minutes. The stirring rate was reduced to 100rpm and the reaction was carried out for 6 hours. The resulting solution after the reaction was centrifuged at 7500 rpm for 2 minutes, the supernatant was discarded, and the solution was washed three times with deionized water. The separated product was dispersed in deionized water and freeze-dried to obtain a white powder product, namely, microcapsules.

[0163] The microcapsule can resist the penetration of water and can resist the penetration of organic solvents (such as ethanol, acetone or methyl methacrylate, etc.).

[0164] Example 10

[0165] The present invention provides a microcapsule material having a hydrophilic / hydrophobic laminated shell structure and a preparation method thereof, which comprises the following steps:

[0166] The embodiment of the present application uses lauric acid in water emulsion, and the mass ratio of the monomer containing hydrophilic group to the monomer containing hydrophobic group is 50%:50%.

[0167] Solution A was prepared by dissolving 0.1g of benzoyl peroxide in 6.5g of lauric acid at 60°C. 15ml of 10% PVA aqueous solution and 50ml of deionized water were mechanically stirred and mixed in a three-necked flask, and preheated at 60°C and nitrogen was passed through the whole process to deoxygenate to prepare solution B. 0.25g of N, N'-methylenebisacrylamide and 1g of methacrylic acid were mechanically shaken to prepare a clear and uniform solution C. 0.833g of methyl methacrylate was used as monomer D. 0.208g of ethylene glycol dimethyl acrylate and 0.208g of methyl methacrylate were prepared to prepare a uniform solution E. The prepared solution A and solution C were added to the preheated solution B, mechanically stirred at 1000rpm for 10 minutes, then heated to 85°C and the stirring rate was reduced to 400rpm for polymerization for 10 minutes. Monomer D was added dropwise over 5 minutes, and solution E was added dropwise over 2.5 minutes after another 10 minutes. The stirring rate was reduced to 100rpm and the reaction was carried out for 6 hours. The resulting solution after the reaction was centrifuged at 7500 rpm for 2 minutes, the supernatant was discarded, and the solution was washed three times with deionized water. The separated product was dispersed in deionized water and freeze-dried to obtain a white powder product, namely, microcapsules.

[0168] The microcapsule can resist the penetration of water and can resist the penetration of organic solvents (such as ethanol, acetone or methyl methacrylate, etc.).

[0169] Embodiment 11

[0170] The present invention provides a microcapsule material having a hydrophilic / hydrophobic laminated shell structure and a preparation method thereof, which comprises the following steps:

[0171] The embodiment of the present application uses lauric acid in water emulsion, and the mass ratio of the monomer containing hydrophilic group to the monomer containing hydrophobic group is 60%:40%.

[0172] Solution A was prepared by dissolving 0.1g of benzoyl peroxide in 6.5g of lauric acid at 60°C. 15ml of 10% PVA aqueous solution and 50ml of deionized water were mechanically stirred and mixed in a three-necked flask, and preheated at 60°C and nitrogen was passed through the whole process to deoxygenate to prepare solution B. 0.3g of N, N'-methylenebisacrylamide and 1.2g of methacrylic acid were mechanically shaken to prepare a clear and uniform solution C. 0.666g of methyl methacrylate was used as monomer D. 0.167g of ethylene glycol dimethyl acrylate and 0.167g of methyl methacrylate were prepared to prepare a uniform solution E. The prepared solution A and solution C were added to the preheated solution B, mechanically stirred at 1000rpm for 10 minutes, then heated to 85°C and the stirring rate was reduced to 400rpm for polymerization for 10 minutes. Monomer D was added dropwise over 5 minutes, and solution E was added dropwise over 2.5 minutes after another 10 minutes. The stirring rate was reduced to 100rpm and the reaction was carried out for 6 hours. The resulting solution after the reaction was centrifuged at 7500 rpm for 2 minutes, the supernatant was discarded, and the solution was washed three times with deionized water. The separated product was dispersed in deionized water and freeze-dried to obtain a white powder product, namely, microcapsules.

[0173] The microcapsule can resist the penetration of water and can resist the penetration of organic solvents (such as ethanol, acetone or methyl methacrylate, etc.).

[0174] Example 12

[0175] The present invention provides a microcapsule material having a hydrophilic / hydrophobic laminated shell structure and a preparation method thereof, which comprises the following steps:

[0176] The embodiment of the present application uses lauric acid in water emulsion, and the mass ratio of the monomer containing hydrophilic group to the monomer containing hydrophobic group is 70%:30%.

[0177] Solution A was prepared by dissolving 0.1g of benzoyl peroxide in 6.5g of lauric acid at 60°C. 15ml of 10% PVA aqueous solution and 50ml of deionized water were mechanically stirred and mixed in a three-necked flask, and preheated at 60°C and nitrogen was passed through the whole process to deoxygenate to prepare solution B. 0.35g of N, N'-methylenebisacrylamide and 1.4g of methacrylic acid were mechanically shaken to prepare a clear and uniform solution C. 0.5g of methyl methacrylate was used as monomer D. 0.125g of ethylene glycol dimethyl acrylate and 0.125g of methyl methacrylate were prepared to prepare a uniform solution E. The prepared solution A and solution C were added to the preheated solution B, mechanically stirred at 1000rpm for 10 minutes, then heated to 85°C and the stirring rate was reduced to 400rpm for polymerization for 10 minutes. Monomer D was added dropwise over 5 minutes, and solution E was added dropwise over 2.5 minutes after another 10 minutes. The stirring rate was reduced to 100rpm and the reaction was carried out for 6 hours. The resulting solution after the reaction was centrifuged at 7500 rpm for 2 minutes, the supernatant was discarded, and the solution was washed three times with deionized water. The separated product was dispersed in deionized water and freeze-dried to obtain a white powder product, namely, microcapsules.

[0178] The microcapsules cannot resist the penetration of water, but can resist the penetration of organic solvents (such as ethanol, acetone or methyl methacrylate, etc.).

[0179] Example 13

[0180] The present invention provides a microcapsule material having a hydrophilic / hydrophobic laminated shell structure and a preparation method thereof, which comprises the following steps:

[0181] The embodiment of the present application uses lauric acid in water emulsion, and the mass ratio of the monomer containing hydrophilic group to the monomer containing hydrophobic group is 80%:20%.

[0182] Solution A was prepared by dissolving 0.1g of benzoyl peroxide in 6.5g of lauric acid at 60°C. 15ml of 10% PVA aqueous solution and 50ml of deionized water were mechanically stirred and mixed in a three-necked flask, and preheated at 60°C and nitrogen was passed through the whole process to deoxygenate to prepare solution B. 0.5g of N, N'-methylenebisacrylamide and 1.5g of methacrylic acid were mechanically shaken to prepare a clear and uniform solution C. 0.333g of methyl methacrylate was used as monomer D. 0.083g of ethylene glycol dimethyl acrylate and 0.083g of methyl methacrylate were prepared to prepare a uniform solution E. The prepared solution A and solution C were added to the preheated solution B, mechanically stirred at 1000rpm for 10 minutes, then heated to 85°C and the stirring rate was reduced to 400rpm for polymerization for 10 minutes. Monomer D was added dropwise over 5 minutes, and solution E was added dropwise over 2.5 minutes after another 10 minutes. The stirring rate was reduced to 100rpm and the reaction was carried out for 6 hours. The resulting solution after the reaction was centrifuged at 7500 rpm for 2 minutes, the supernatant was discarded, and the solution was washed three times with deionized water. The separated product was dispersed in deionized water and freeze-dried to obtain a white powder product, namely, microcapsules.

[0183] The microcapsules cannot resist the penetration of water, but can resist the penetration of organic solvents (such as ethanol, acetone or methyl methacrylate, etc.).

[0184] Embodiment 14

[0185] The present invention provides a microcapsule material having a hydrophilic / hydrophobic laminated shell structure and a preparation method thereof, which comprises the following steps:

[0186] The embodiment of the present application uses lauric acid in water emulsion, and the mass ratio of the monomer containing hydrophilic group to the monomer containing hydrophobic group is 90%:10%.

[0187] Solution A was prepared by dissolving 0.1g of benzoyl peroxide in 6.5g of lauric acid at 60°C. 15ml of 10% PVA aqueous solution and 50ml of deionized water were mechanically stirred and mixed in a three-necked flask, and preheated at 60°C and nitrogen was passed through the whole process to deoxygenate to prepare solution B. 0.45g of N, N'-methylenebisacrylamide and 1.8g of methacrylic acid were mechanically shaken to prepare a clear and uniform solution C. 0.166g of methyl methacrylate was used as monomer D. 0.042g of ethylene glycol dimethyl acrylate and 0.042g of methyl methacrylate were prepared to prepare a uniform solution E. The prepared solution A and solution C were added to the preheated solution B, mechanically stirred at 1000rpm for 10 minutes, then heated to 85°C and the stirring rate was reduced to 400rpm for polymerization for 10 minutes. Monomer D was added dropwise over 5 minutes, and solution E was added dropwise over 2.5 minutes after another 10 minutes. The stirring rate was reduced to 100rpm and the reaction was carried out for 6 hours. The resulting solution after the reaction was centrifuged at 7500 rpm for 2 minutes, the supernatant was discarded, and the solution was washed three times with deionized water. The separated product was dispersed in deionized water and freeze-dried to obtain a white powder product, namely, microcapsules.

[0188] The microcapsules cannot resist the penetration of water, but can resist the penetration of organic solvents (such as ethanol, acetone or methyl methacrylate, etc.).

[0189] Embodiment 15

[0190] The present invention provides a functional microcapsule material having a hydrophilic / hydrophobic laminated shell structure and a preparation method thereof, which comprises the following steps:

[0191] The embodiment of the present application uses lauric acid in water emulsion, and the mass ratio of monomer to capsule core material is 10%:90%.

[0192] Solution A was prepared by dissolving 0.1g of benzoyl peroxide in 22.5g of lauric acid at 60°C. 15ml of 10% PVA aqueous solution and 50ml of deionized water were mechanically stirred and mixed in a three-necked flask, and preheated at 60°C and nitrogen was passed through the whole process to deoxygenate to prepare solution B. 0.45g of N, N'-methylenebisacrylamide and 1.8g of methacrylic acid were mechanically shaken to prepare a clear and uniform solution C. 0.166g of methyl methacrylate was used as monomer D. 0.042g of ethylene glycol dimethyl acrylate and 0.042g of methyl methacrylate were prepared to prepare a uniform solution E. The prepared solution A and solution C were added to the preheated solution B, mechanically stirred at 1000rpm for 10 minutes, then heated to 85°C and the stirring rate was reduced to 400rpm for polymerization for 10 minutes. Monomer D was added dropwise over 5 minutes, and solution E was added dropwise over 2.5 minutes after another 10 minutes. The stirring rate was reduced to 100rpm and the reaction was carried out for 6 hours. The resulting solution after the reaction was centrifuged at 7500 rpm for 2 minutes, the supernatant was discarded, and the solution was washed three times with deionized water. The separated product was dispersed in deionized water and freeze-dried to obtain a white powder product, namely, microcapsules.

[0193] Because the polymer shell is too thin, it is easily damaged by mechanical means, which results in the microcapsules being unable to protect the core material.

[0194] Example 16

[0195] The present invention provides a microcapsule material having a hydrophilic / hydrophobic laminated shell structure and a preparation method thereof, which comprises the following steps:

[0196] The embodiment of the present application uses lauric acid in water emulsion, and the mass ratio of monomer to capsule core material is 20%:80%.

[0197] Solution A was prepared by dissolving 0.1g of benzoyl peroxide in 10g of lauric acid at 60°C. 15ml of 10% PVA aqueous solution and 50ml of deionized water were mechanically stirred and mixed in a three-necked flask, and preheated at 60°C and nitrogen was passed through the whole process to deoxygenate to prepare solution B. 0.45g of N, N'-methylenebisacrylamide and 1.8g of methacrylic acid were mechanically shaken to prepare a clear and uniform solution C. 0.166g of methyl methacrylate was used as monomer D. 0.042g of ethylene glycol dimethyl acrylate and 0.042g of methyl methacrylate were prepared to prepare a uniform solution E. The prepared solution A and solution C were added to the preheated solution B, mechanically stirred at 1000rpm for 10 minutes, then heated to 85°C and the stirring rate was reduced to 400rpm for polymerization for 10 minutes. Monomer D was added dropwise over 5 minutes, and solution E was added dropwise over 2.5 minutes after another 10 minutes. The stirring rate was reduced to 100rpm and the reaction was carried out for 6 hours. The resulting solution after the reaction was centrifuged at 7500 rpm for 2 minutes, the supernatant was discarded, and the solution was washed three times with deionized water. The separated product was dispersed in deionized water and freeze-dried to obtain a white powder product, namely, microcapsules.

[0198] The prepared microcapsules are relatively complete and can resist the penetration of water and organic solvents (such as ethanol, acetone or methyl methacrylate, etc.).

[0199] Embodiment 17

[0200] The present invention provides a microcapsule material having a hydrophilic / hydrophobic laminated shell structure and a preparation method thereof, which comprises the following steps:

[0201] The embodiment of the present application uses lauric acid in water emulsion, and the mass ratio of monomer to capsule core material is 30%:70%.

[0202] Solution A was prepared by dissolving 0.1g of benzoyl peroxide in 5.8g of lauric acid at 60°C. 15ml of 10% PVA aqueous solution and 50ml of deionized water were mechanically stirred and mixed in a three-necked flask, and preheated at 60°C and nitrogen was passed through the whole process to deoxygenate to prepare solution B. 0.45g of N, N'-methylenebisacrylamide and 1.8g of methacrylic acid were mechanically shaken to prepare a clear and uniform solution C. 0.166g of methyl methacrylate was used as monomer D. 0.042g of ethylene glycol dimethyl acrylate and 0.042g of methyl methacrylate were prepared to prepare a uniform solution E. The prepared solution A and solution C were added to the preheated solution B, mechanically stirred at 1000rpm for 10 minutes, then heated to 85°C and the stirring rate was reduced to 400rpm for polymerization for 10 minutes. Monomer D was added dropwise over 5 minutes, and solution E was added dropwise over 2.5 minutes after another 10 minutes. The stirring rate was reduced to 100rpm and the reaction was carried out for 6 hours. The resulting solution after the reaction was centrifuged at 7500 rpm for 2 minutes, the supernatant was discarded, and the solution was washed three times with deionized water. The separated product was dispersed in deionized water and freeze-dried to obtain a white powder product, namely, microcapsules.

[0203] The prepared microcapsules have a complete structure and can resist the penetration of water and organic solvents.

[0204] Embodiment 18

[0205] The present invention provides a microcapsule material having a hydrophilic / hydrophobic laminated shell structure and a preparation method thereof, which comprises the following steps:

[0206] The embodiment of the present application uses lauric acid in water emulsion, and the mass ratio of monomer to capsule core material is 40%:60%.

[0207] Solution A was prepared by dissolving 0.1g of benzoyl peroxide in 3.75g of lauric acid at 60°C. 15ml of 10% PVA aqueous solution and 50ml of deionized water were mechanically stirred and mixed in a three-necked flask, and preheated at 60°C and nitrogen was passed through the whole process to deoxygenate to prepare solution B. 0.45g of N, N'-methylenebisacrylamide and 1.8g of methacrylic acid were mechanically shaken to prepare a clear and uniform solution C. 0.166g of methyl methacrylate was used as monomer D. 0.042g of ethylene glycol dimethyl acrylate and 0.042g of methyl methacrylate were prepared to prepare a uniform solution E. The prepared solution A and solution C were added to the preheated solution B, mechanically stirred at 1000rpm for 10 minutes, then heated to 85°C and the stirring rate was reduced to 400rpm for polymerization for 10 minutes. Monomer D was added dropwise over 5 minutes, and solution E was added dropwise over 2.5 minutes after another 10 minutes. The stirring rate was reduced to 100rpm and the reaction was carried out for 6 hours. The resulting solution after the reaction was centrifuged at 7500 rpm for 2 minutes, the supernatant was discarded, and the solution was washed three times with deionized water. The separated product was dispersed in deionized water and freeze-dried to obtain a white powder product, namely, microcapsules.

[0208] The prepared microcapsules have a complete structure and can resist the penetration of water and organic solvents (such as ethanol, acetone or methyl methacrylate, etc.).

[0209] Embodiment 19

[0210] The present invention provides a microcapsule material having a hydrophilic / hydrophobic laminated shell structure and a preparation method thereof, which comprises the following steps:

[0211] The embodiment of the present application uses lauric acid in water emulsion, and the mass ratio of the monomer to the capsule core material is 50%:50%.

[0212] Solution A was prepared by dissolving 0.1g of benzoyl peroxide in 2.5g of lauric acid at 60°C. 15ml of 10% PVA aqueous solution and 50ml of deionized water were mechanically stirred and mixed in a three-necked flask, and preheated at 60°C and nitrogen was passed through the whole process to deoxygenate to prepare solution B. 0.45g of N, N'-methylenebisacrylamide and 1.8g of methacrylic acid were mechanically shaken to prepare a clear and uniform solution C. 0.166g of methyl methacrylate was used as monomer D. 0.042g of ethylene glycol dimethyl acrylate and 0.042g of methyl methacrylate were prepared to prepare a uniform solution E. The prepared solution A and solution C were added to the preheated solution B, mechanically stirred at 1000rpm for 10 minutes, then heated to 85°C and the stirring rate was reduced to 400rpm for polymerization for 10 minutes. Monomer D was added dropwise over 5 minutes, and solution E was added dropwise over 2.5 minutes after another 10 minutes. The stirring rate was reduced to 100rpm and the reaction was carried out for 6 hours. The resulting solution after the reaction was centrifuged at 7500 rpm for 2 minutes, the supernatant was discarded, and the solution was washed three times with deionized water. The separated product was dispersed in deionized water and freeze-dried to obtain a white powder product, namely, microcapsules.

[0213] The prepared microcapsules have a complete structure and can resist the penetration of water and organic solvents (such as ethanol, acetone or methyl methacrylate, etc.).

[0214] Embodiment 20

[0215] The present invention provides a microcapsule material having a hydrophilic / hydrophobic laminated shell structure and a preparation method thereof, which comprises the following steps:

[0216] The present embodiment uses a cyclohexane-in-water emulsion, wherein the volume fraction of the dispersed phase is 7.14%.

[0217] 0.1g of ammonium persulfate was dissolved in 5g of water at room temperature to prepare solution A, 2g of Span-80 was dissolved in 65ml of cyclohexane in a three-necked flask and mechanically stirred to mix, nitrogen was passed through the whole process to deoxygenate to prepare solution B, 0.2g of ethylene glycol diacrylate and 0.8g of methyl methacrylate were mechanically shaken to prepare clear and uniform solution C, 1g of methacrylic acid was used as monomer D, 0.25g of N, N'-methylenebisacrylamide and 0.25g of methacrylic acid were prepared to prepare uniform solution E. The prepared solution A and solution C were added to solution B, mechanically stirred at 1000rpm for 10 minutes, then heated to 60°C and the stirring rate was reduced to 400rpm for polymerization for 10 minutes, monomer D was added dropwise over 5 minutes, and solution E was added dropwise over 2.5 minutes after another 10 minutes, and the stirring rate was reduced to 100rpm for reaction for 6 hours. The resulting solution after the reaction was centrifuged at 7500 rpm for 2 minutes, the supernatant was discarded, and the solution was washed three times with hexane. The separated product was dried at 60° C., i.e., microcapsules.

[0218] The prepared microcapsules have a complete structure and can resist the penetration of water and organic solvents (such as ethanol, acetone or methyl methacrylate, etc.).

[0219] Embodiment 21

[0220] A microcapsule material with a hydrophilic / hydrophobic laminated shell structure and a preparation method thereof, comprising the following steps:

[0221] The present embodiment uses a cyclohexane-in-water emulsion, wherein the volume fraction of the dispersed phase containing the active ingredient water-soluble fluoroboron dipyrrole anticancer photosensitizer in the core water is 7.14%.

[0222] 0.1g ammonium persulfate and 0.1g water-soluble fluoroboron dipyrrole anticancer photosensitizer were dissolved in 5g water at room temperature to prepare solution A, 2g Span-80 was dissolved in 65ml cyclohexane in a three-necked flask and mechanically stirred to mix, nitrogen was passed through the whole process to deoxygenate to prepare solution B, 0.2g ethylene glycol diacrylate and 0.8g methyl methacrylate were mechanically shaken to prepare clear and uniform solution C, 1g methacrylic acid was used as monomer D, 0.25g N, N'-methylenebisacrylamide and 0.25g methacrylic acid were prepared to prepare uniform solution E. The prepared solution A and solution C were added to solution B, mechanically stirred at 1000rpm for 10 minutes, then heated to 60℃ and the stirring rate was reduced to 400rpm for polymerization for 10 minutes, monomer D was added dropwise over 5 minutes, and solution E was added dropwise over 2.5 minutes after 10 minutes, and the stirring rate was reduced to 100rpm for reaction for 6 hours. The resulting solution after the reaction was centrifuged at 7500 rpm for 2 minutes, the supernatant was discarded, and the solution was washed three times with hexane. The separated product was dried at 60° C., i.e., microcapsules.

[0223] The prepared microcapsules have a complete structure and can resist the penetration of water and organic solvents (such as ethanol, acetone or methyl methacrylate, etc.).

[0224] Embodiment 22

[0225] The present application example uses paraffin-in-water emulsion.

[0226] 1.25g of methyl methacrylate, 0.25g of ethylene glycol dimethacrylate and 0.1g of benzoyl peroxide were dissolved in 5g of paraffin at 60°C to prepare solution A. 15ml of 10% PVA aqueous solution and 50ml of deionized water were mechanically stirred and mixed in a three-necked flask, and preheated at 60°C and nitrogen was passed through the whole process to deoxygenate to prepare solution B. 0.2g of N, N'-methylenebisacrylamide and 0.8g of methacrylic acid were mechanically shaken to prepare a clear and uniform solution C. The prepared solution A was added to the preheated solution B, and the temperature was raised to 85°C after mechanical stirring at 1000rpm for 10 minutes, and the stirring rate was reduced to 400rpm for polymerization for 10 minutes. Solution C was added dropwise over 2.5 minutes, and the stirring rate was reduced to 100rpm for reaction for 6 hours. The resulting solution after the reaction was centrifuged at 7500rpm for 2 minutes, the clear liquid was discarded, and then washed with deionized water three times. The separated product was dispersed in deionized water and freeze-dried to obtain a white powder product, i.e., microcapsules.

[0227] It can form a complete core-shell structure and resist the penetration of water and organic solvents such as methyl methacrylate, ethanol, acetone, etc. It has good dispersibility in aqueous solution systems (such as construction cement).

[0228] Comparative Example 1-1

[0229] The comparative example of the present application uses lauric acid in water emulsion and only uses monomers containing hydrophilic groups.

[0230] Solution A was prepared by dissolving 0.1g benzoyl peroxide in 5g lauric acid at 60℃, mechanically stirring and mixing 15ml 10% PVA aqueous solution and 50ml deionized water in a three-necked flask, and preheating at 60℃ and deoxygenating with nitrogen gas during the whole process to prepare solution B, and mechanically shaking 0.5g N, N'-methylenebisacrylamide and 2g methacrylic acid to prepare a clear and uniform solution C. The prepared solution A and solution C were added to the preheated solution B, mechanically stirred at 1000rpm for 10 minutes, then heated to 85℃, the stirring rate was reduced to 400rpm, and the polymerization was carried out for 10 minutes, and the stirring rate was reduced to 100rpm for reaction for 6 hours. The resulting solution after the reaction was centrifuged at 7500rpm for 2 minutes, the clear liquid was discarded, and then washed with deionized water three times, and the separated product was dispersed in deionized water and freeze-dried to obtain the product.

[0231] Scanning electron microscopy results showed that core-shell microcapsules could not be formed. During the preparation process, polymethacrylic acid could not resist the swelling of water, resulting in the leakage of lauric acid.

[0232] Comparative Example 1-2

[0233] The comparative example of the present application uses a lauric acid-in-water emulsion and only uses a hydrophobic monomer.

[0234] 2g of methyl methacrylate, 0.5g of ethylene glycol dimethacrylate and 0.1g of benzoyl peroxide were dissolved in 5g of lauric acid at 60°C to prepare solution A. 15ml of 10% PVA aqueous solution and 50ml of deionized water were mechanically stirred and mixed in a three-necked flask, and preheated at 60°C and nitrogen was passed through the whole process to deoxygenate to prepare solution B. The prepared solution A was added to the preheated solution B, and the temperature was raised to 85°C after mechanical stirring at 1000rpm for 10 minutes. The stirring rate was reduced to 400rpm for polymerization for 10 minutes, and the stirring rate was reduced to 100rpm for reaction for 6 hours. The resulting solution after the reaction was centrifuged at 7500rpm for 2 minutes, the supernatant was discarded, and then washed with deionized water three times. The separated product was dispersed in deionized water and freeze-dried to obtain a white powdery product.

[0235] The scanning electron microscopy results showed that a core-shell structure of polymethyl methacrylate wrapped in lauric acid could not be formed. Instead, a structure of lauric acid wrapped in polymethyl methacrylate was formed. This was mainly because the interfacial tension between polymethyl methacrylate and water was greater than the interfacial tension between lauric acid and water. Therefore, the spreading of polymethyl methacrylate at the interface between water and lauric acid could not be achieved.

[0236] Comparative Examples 1-3

[0237] The comparative example of the present application uses a paraffin-in-water emulsion and only uses a hydrophobic monomer.

[0238] 2g of methyl methacrylate, 0.5g of ethylene glycol dimethacrylate and 0.1g of benzoyl peroxide were dissolved in 5g of paraffin at 60°C to prepare solution A, 15ml of 10% PVA aqueous solution and 50ml of deionized water were mechanically stirred and mixed in a three-necked flask, and preheated at 60°C and nitrogen was passed through the whole process to deoxygenate to prepare solution B. The prepared solution A was added to the preheated solution B, and the temperature was raised to 85°C after mechanical stirring at 1000rpm for 10 minutes, and the stirring rate was reduced to 400rpm for polymerization for 10 minutes, and the stirring rate was reduced to 100rpm for reaction for 6 hours. The resulting solution after the reaction was centrifuged at 7500rpm for 2 minutes, the supernatant was discarded, and then washed with deionized water three times, and the separated product was dispersed in deionized water and freeze-dried to obtain a white powder product.

[0239] Microcapsules of polymethyl methacrylate-coated paraffin can be formed, but they cannot resist the penetration of organic solvents such as acetone and methyl methacrylate.

[0240] The above is an exemplary description of the embodiments of the present invention. However, the protection scope of the present invention is not limited to the above embodiments. Any modification, equivalent substitution, improvement, etc. made by those skilled in the art within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing microcapsules, characterized in that: The microcapsule comprises a core layer and a shell layer, wherein the core layer is located inside the shell layer; the shell layer of the microcapsule comprises at least two layers, one layer is a hydrophobic polymer material layer, and the other layer is a hydrophilic polymer material layer; The microcapsules are prepared by one of the following two methods; The first method includes the following steps: (S1) preparing an oil-in-water emulsion, wherein the oil phase includes a core material; (S2) adding a monomer containing a hydrophilic group and an initiator to the emulsion of step (S1) to prepare a hydrophilic polymer material layer; (S3) continuing to drop a portion of the monomer containing a hydrophobic group into step (S2), and then adding the remaining portion of the monomer containing a hydrophobic group to prepare a microcapsule, wherein the microcapsule has a structure of a hydrophobic outer layer and a hydrophilic inner layer; The second method includes the following steps: (S1) preparing a water-in-oil emulsion, wherein the water phase includes a core material selected from water-soluble active ingredients, or the oil phase includes a core material selected from water-insoluble substances; (S2) adding a monomer containing a hydrophobic group and an initiator to the emulsion of step (S1) to prepare a hydrophobic polymer material layer; (S3) adding a portion of the monomer containing a hydrophilic group to step (S2), and then adding the remaining portion of the monomer containing a hydrophilic group to prepare a microcapsule having a structure of a hydrophilic outer layer and a hydrophobic inner layer; The polymer material inside the shell is cross-linked, and the cross-linking agent used is N, N'-methylenebisacrylamide and / or ethylene glycol diacrylate; The ratio of the sum of the mass of the monomer containing the hydrophilic group and the cross-linking agent to the mass of the monomer containing the hydrophobic group is (1-99): (99-1); The ratio of the sum of the mass of the monomer containing the hydrophilic group, the monomer containing the hydrophobic group and the cross-linking agent to the mass of the microcapsule core material is (10-50): (90-50); The monomer containing a hydrophilic group is selected from methacrylic acid; The monomer containing a hydrophobic group is selected from methyl methacrylate or ethyl methacrylate.

2. The preparation method according to claim 1, characterized in that: The oil-in-water emulsion or water-in-oil emulsion is selected from one of paraffin-in-water emulsion, fatty acid-in-water emulsion, water-in-cyclohexane emulsion and water-in-toluene emulsion; or, the water phase of the water-in-oil emulsion includes a water-soluble active ingredient.

3. The preparation method according to claim 1, characterized in that: A dispersant and / or an emulsifier is also added in step (S2) and / or step (S3).

4. Microcapsules prepared by the method according to any one of claims 1 to 3.

5. The microcapsule according to claim 4, characterized in that The material forming the core layer, i.e. the core material, is selected from alcohol compounds with 4 to 50 carbon atoms, organic acid compounds with 4 to 50 carbon atoms, alkanes or aromatic hydrocarbon compounds with 6 to 50 carbon atoms, or at least one of the esters obtained by reacting the above alcohol compounds with 4 to 50 carbon atoms with organic acid compounds with 4 to 50 carbon atoms, or selected from water-soluble active ingredients.

6. Use of the microcapsules according to claim 4 or 5, characterized in that: For temperature control and / or energy storage.

7. The use according to claim 6, characterized in that: For temperature control and / or energy storage in the building and medical sectors.

8. A bone cement, characterized in that: The filler of the bone cement includes the microcapsules described in claim 4 or 5.

9. The bone cement according to claim 8, characterized in that The bone cement is polymethacrylate bone cement.

10. The bone cement according to claim 8 or 9, characterized in that: The mass percentage of the microcapsules in the bone cement is 10% to 50%.

11. The bone cement according to claim 10, characterized in that The mass percentage of the microcapsules in the bone cement is 20% to 40%.

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