Self-repairing microcapsule, preparation method and application thereof
By combining benzotriazole, polymaleic anhydride, and linseed oil as self-healing agents, self-healing microcapsules were prepared and applied to coatings. This solved the problem of insufficient response of self-healing microcapsules in complex environments in the prior art, and achieved efficient self-healing and anti-corrosion effects in coatings.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- ZHONGKE JIEHENG (SHANDONG) NEW MATERIALS CO LTD
- Filing Date
- 2024-08-01
- Publication Date
- 2026-06-12
AI Technical Summary
Existing self-healing microcapsules cannot effectively respond to constantly changing corrosion conditions in complex environments, and self-healing agents with single structures cannot meet the self-healing needs of multifunctional coatings.
A combination of benzotriazole, polymaleic anhydride, and linseed oil was used as a self-healing agent, and sodium poly(ethylene-co-methacrylate) was used as the capsule wall material. Self-healing microcapsules were prepared by oil-in-water emulsification and then added to coatings.
It achieves effective self-healing of coatings in complex environments, enhances the stability and protective strength of coatings, and significantly improves the corrosion resistance of coatings through the synergistic effect of different corrosion inhibitors.
Smart Images
Figure BDA0004973516370000041 
Figure BDA0004973516370000051
Abstract
Description
Technical Field
[0001] This invention belongs to the field of self-healing microcapsule technology, specifically relating to a self-healing microcapsule, its preparation method, and its application. Background Technology
[0002] With the improvement of people's living standards, the development of interior wall coatings is constantly moving towards multi-functional and environmentally friendly green building coatings, building upon their original decorative functions. Multi-functionality refers to coatings that, in addition to decoration, also possess health benefits such as energy saving, humidity regulation, deodorization, antibacterial and mildew prevention, air purification, sound insulation, and shielding of harmful electromagnetic waves. However, coatings are prone to developing micro-cracks under external forces and prolonged exposure to the environment. These micro-cracks allow corrosive agents such as oxygen and moisture to easily penetrate the coating and cause corrosion.
[0003] To avoid the aforementioned phenomena, engineers have developed self-healing protective coatings. When microcracks appear in the coating, the self-healing coating can repair the cracks while maintaining the integrity and functionality of the coating. Microencapsulation technology has been developing in the field of self-healing for over 20 years. Its structure mainly consists of a core material and a capsule wall. When self-healing microcapsules are added to the coating, when cracks appear on the coating surface, the microcapsules inside the coating also rupture. The core material inside flows out and can repair or inhibit corrosion, thereby achieving the purpose of self-healing of the coating.
[0004] In existing technologies, the core material of self-healing microcapsules, i.e., the self-healing agent, is usually a single agent or a combination of multiple agents. In complex environments, single-structure self-healing agents cannot respond to constantly changing corrosion conditions; therefore, compound self-healing agents are more practical. For example, Jia Guixiao et al. found a significant synergistic effect between surfactants and thiourea derivatives (DOI:10.1016 / j.corsci.2022.110199); Zhao Jingmao et al. found a good synergistic effect between imidazoline quaternary ammonium salt and sodium dodecyl sulfonate, which can inhibit pitting corrosion (DOI:10.3866 / PKU.WHXB201402111); however, there are no reports on the combined use of benzotriazole, polymaleic anhydride, and linseed oil. Summary of the Invention
[0005] To address the shortcomings of the existing technology, the purpose of this invention is to provide a self-healing microcapsule, its preparation method, and its application.
[0006] To achieve the above objectives, the present invention adopts the following technical solution:
[0007] In a first aspect, the present invention provides a self-healing microcapsule comprising a core material and a capsule wall covering the outer surface of the core material, wherein the core material is a self-healing reagent and the capsule wall is sodium poly(ethylene-co-methacrylate); the self-healing reagent is composed of benzotriazole, polymaleic anhydride and linseed oil.
[0008] Preferably, the weight ratio of benzotriazole, polymaleic anhydride and linseed oil is (1-2):(1-2):4.
[0009] A second aspect of the present invention provides a method for preparing the above-mentioned self-healing microcapsules, comprising the following steps:
[0010] (1) Benzotriazole was dissolved in acetone to obtain an organic phase, and then polymaleic anhydride and linseed oil were added to obtain an oil phase mixture;
[0011] (2) Sodium poly(ethylene-co-methacrylic acid) is dissolved in water to obtain an aqueous phase. The oil phase mixture is added to the aqueous phase and stirred to emulsify, resulting in an oil-in-water emulsion. The oil-in-water emulsion is dried to obtain self-healing microcapsules.
[0012] Preferably, in step (2), the mass ratio between sodium poly(ethylene-co-methacrylic acid) solution and water is 1:(10-20), and the weight ratio between the oil phase mixture and the water phase is (0.2-1):1.
[0013] Preferably, in step (2), the stirring rate is 400-500 r / min and the time is 10-20 min; the emulsification time is 2-3 h.
[0014] Preferably, in step (2), the drying temperature is 15-40℃.
[0015] A third aspect of the present invention provides the application of the above-described self-healing microcapsules in the preparation of self-healing coatings.
[0016] A fourth aspect of the present invention provides a self-healing coating, comprising the following raw materials in parts by weight:
[0017] Film-forming resin 30-50 parts, self-healing microcapsules 5-30 parts, diluent 30-50 parts, defoamer 30-50 parts, coupling agent 3-5 parts, toughening agent 3-10 parts;
[0018] The self-healing microcapsules are self-healing microcapsules prepared by the above method.
[0019] Preferably, the film-forming resin is one or more selected from epoxy resin, polyurethane resin, phenolic resin, acrylic resin, and silicone resin.
[0020] Preferably, the diluent is one or more of acetone, ethanol, xylene, or ethyl acetate.
[0021] Preferably, the defoamer is one or more of alcohol-based defoamers, phosphoric acid-based defoamers, and amine-based defoamers.
[0022] Preferably, the coupling agent is a silane coupling agent or a titanate coupling agent.
[0023] Preferably, the toughening agent is one or more of carboxymethyl cellulose, hydroxymethyl cellulose, and hydroxyethyl cellulose.
[0024] The beneficial effects of this invention are:
[0025] (1) The self-healing microcapsules provided by the present invention have good repair performance. When added to the coating, they can be uniformly dispersed in the coating system, so that the coating has high stability and self-healing properties.
[0026] (2) This invention adds organic corrosion inhibitor (benzotriazole) and polymer corrosion inhibitor (polymaleic anhydride) to flaxseed oil, giving full play to the synergistic effect of different types of corrosion inhibitors, effectively repairing cracks caused by corrosion in the coating, and ensuring the protective strength of the coating. Detailed Implementation
[0027] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.
[0028] To enable those skilled in the art to better understand the technical solution of this application, the technical solution of this application will be described in detail below with reference to specific embodiments.
[0029] In the following examples and test cases, the CAS number of sodium poly(ethylene-co-methacrylate) used is 25608-26-8; the CAS number of polymaleic anhydride is 24937-72-2; the CAS number of linseed oil is 8001-26-1; and the CAS number of benzotriazole is 95-14-7.
[0030] Example 1: Preparation of self-healing microcapsules.
[0031] (1) Benzotriazole was dissolved in acetone to obtain an organic phase, and then polymaleic anhydride and linseed oil were added to obtain an oil phase mixture; the weight ratio of benzotriazole, polymaleic anhydride and linseed oil was 1:1:4.
[0032] (2) Sodium poly(ethylene-co-methacrylic acid) is dissolved in water to obtain an aqueous phase. An oil phase mixture is added to the aqueous phase. The weight ratio between the oil phase mixture and the aqueous phase is 0.5:1. The mixture is then stirred at 400 r / min for 10 min and emulsified for 2 h to obtain an oil-in-water emulsion. The oil-in-water emulsion is dried at 30 °C to obtain self-healing microcapsules.
[0033] Example 2: Preparation of self-healing microcapsules.
[0034] (1) Benzotriazole was dissolved in acetone to obtain an organic phase, and then polymaleic anhydride and linseed oil were added to obtain an oil phase mixture; the weight ratio of benzotriazole, polymaleic anhydride and linseed oil was 2:2:4.
[0035] (2) Sodium poly(ethylene-co-methacrylic acid) is dissolved in water to obtain an aqueous phase. An oil phase mixture is added to the aqueous phase. The weight ratio between the oil phase mixture and the aqueous phase is 1:1. The mixture is then stirred at 500 r / min for 20 min and emulsified for 3 h to obtain an oil-in-water emulsion. The oil-in-water emulsion is dried at 40 °C to obtain self-healing microcapsules.
[0036] Example 3: Preparation of self-healing microcapsules.
[0037] (1) Benzotriazole was dissolved in acetone to obtain an organic phase, and then polymaleic anhydride and linseed oil were added to obtain an oil phase mixture; the weight ratio of benzotriazole, polymaleic anhydride and linseed oil was 0.5:0.5:4.
[0038] (2) Sodium poly(ethylene-co-methacrylic acid) was dissolved in water to obtain an aqueous phase. An oil phase mixture was added to the aqueous phase. The weight ratio between the oil phase mixture and the aqueous phase was 0.2:1. The mixture was then stirred at 450 r / min for 15 min and emulsified for 2.5 h to obtain an oil-in-water emulsion. The oil-in-water emulsion was dried at 15 °C to obtain self-healing microcapsules.
[0039] Example 4: Preparation of self-healing coating.
[0040] The self-healing coating of this embodiment is composed of the following raw materials in parts by weight:
[0041] 30 parts epoxy resin, 20 parts self-healing microcapsules, 30 parts ethanol, 30 parts phosphoric acid defoamer, 3 parts silane coupling agent, and 5 parts carboxymethyl cellulose.
[0042] Epoxy resin, self-healing microcapsules, ethanol, phosphate defoamer, silane coupling agent and carboxymethyl cellulose were mixed and stirred in a sealed manner at a speed of 1500 rpm for 4 hours using a high-speed shear mixer to obtain a self-healing coating.
[0043] Comparative Example 1:
[0044] Benzotriazole was dissolved in acetone to obtain an organic phase, and sodium poly(ethylene-co-methacrylic acid) was dissolved in water to obtain an aqueous phase. The organic phase was added to the aqueous phase, and the weight ratio of the organic phase to the aqueous phase was 0.5:1. The mixture was then stirred at 400 r / min for 10 min and emulsified for 2 h to obtain an oil-in-water emulsion. The oil-in-water emulsion was dried at 30 °C to obtain self-healing microcapsules.
[0045] Comparative Example 2:
[0046] Sodium poly(ethylene-co-methacrylic acid) was dissolved in water to obtain an aqueous phase. Polymaleic anhydride was added to the aqueous phase at a weight ratio of 0.5:1. The mixture was then stirred at 400 r / min for 10 min and emulsified for 2 h to obtain an oil-in-water emulsion. The oil-in-water emulsion was dried at 30 °C to obtain self-healing microcapsules.
[0047] Comparative Example 3:
[0048] Sodium poly(ethylene-co-methacrylic acid) was dissolved in water to obtain an aqueous phase. Flaxseed oil was added to the aqueous phase at a weight ratio of 0.5:1. The mixture was then stirred at 400 r / min for 10 min and emulsified for 2 h to obtain an oil-in-water emulsion. The oil-in-water emulsion was dried at 30 °C to obtain self-healing microcapsules.
[0049] Test example: Corrosion resistance test of coating.
[0050] (1) Experimental method:
[0051] The self-healing coating was prepared according to the method in Example 4 and laid as a coating with a thickness of 80 μm. It was divided into control groups 1-3, a blank control group, and an experimental group, wherein:
[0052] The experimental group was supplemented with the self-healing microcapsules prepared in Example 1;
[0053] The blank control group did not receive the self-repairing microcapsules;
[0054] Control group 1 was supplemented with self-healing microcapsules prepared in comparative example 1;
[0055] Control group 2 was supplemented with self-healing microcapsules prepared in comparative example 2;
[0056] Control group 3 was supplemented with the self-healing microcapsules prepared in comparative example 3.
[0057] The coatings of each group were penetrated, and then the samples were immersed in a 3.5% NaCl solution as a corrosive medium. Electrochemical impedance spectroscopy was performed after 3 hours, and the results are shown in the table below. The normative testing standard refers to GB / T 39482.3-2020 "Electrochemical Impedance Spectroscopy (EIS) of Painted and Unpainted Metal Samples".
[0058] (2) Experimental results:
[0059] Table 1. Charge transfer resistance at the penetration points of each coating after immersion in 3.5% NaCl solution for 3 hours.
[0060]
[0061]
[0062] As can be seen from the above data, the self-healing microcapsules provided by the present invention can effectively improve the corrosion resistance of coatings, and polymaleic anhydride, linseed oil and benzotriazole have a synergistic effect.
[0063] The above description is only a preferred embodiment of the present invention and is not intended to limit the implementation and application of the present invention. Any modifications, equivalent substitutions, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.
Claims
1. A self-healing microcapsule, characterized in that, Includes the core material and the capsule wall covering the outer surface of the core material; The core material is a self-healing agent, and the capsule wall is sodium poly(ethylene-co-methacrylate); The self-healing reagent is prepared by mixing benzotriazole, polymaleic anhydride and linseed oil in a mass ratio of (1-2):(1-2):4; The self-healing microcapsules are prepared by the following method: (1) Benzotriazole was dissolved in acetone to obtain an organic phase, and then polymaleic anhydride and linseed oil were added to obtain an oil phase mixture; (2) Sodium poly(ethylene-co-methacrylic acid) is dissolved in water to obtain an aqueous phase. The oil phase mixture is added to the aqueous phase and stirred to emulsify, resulting in an oil-in-water emulsion. The oil-in-water emulsion is dried to obtain self-healing microcapsules.
2. The self-healing microcapsule as described in claim 1, characterized in that, In step (2), the mass ratio of sodium poly(ethylene-co-methacrylic acid) dissolved in water is 1:(10-20), and the weight ratio of the oil phase mixture to the water phase is (0.2-1):
1.
3. The self-healing microcapsule as described in claim 1, characterized in that, In step (2), the stirring rate is 400-500 r / min and the time is 10-20 min; the emulsification time is 2-3 h.
4. The self-healing microcapsule as described in claim 1, characterized in that, In step (2), the drying temperature is 15-40℃.
5. The use of the self-healing microcapsules according to any one of claims 1-4 in the preparation of self-healing coatings.
6. The application as described in claim 5, characterized in that, The self-healing micro-coating is composed of the following raw materials in parts by weight: The film-forming resin comprises 30-50 parts, the self-healing microcapsules as described in any one of claims 1-4 comprises 5-30 parts, the diluent comprises 30-50 parts, the defoamer comprises 30-50 parts, the coupling agent comprises 3-5 parts, and the toughening agent comprises 3-10 parts.