Anticorrosion and thermal insulation coating and preparation method thereof

Abstract

The invention relates to the technical field of coatings, and discloses an anti-corrosion and thermal insulation coating and a preparation method thereof. The coating is formed by mixing epoxy resin as a film-forming substance and modified inorganic mineral additives and hollow glass microspheres as auxiliary materials. The modified inorganic mineral additive is prepared by modifying a polymer macromolecular substance on the surface of sepiolite. The polymer macromolecular substance can participate in the subsequent curing process of epoxy acrylic resin, thereby achieving mutual entanglement and cross-linking with the epoxy acrylic resin, improving the density of the coating structure, and promoting the uniform dispersion of sepiolite in the coating. Furthermore, the layered chain structure of sepiolite itself is utilized to extend the penetration path of corrosive media, thereby enhancing the anti-corrosion effect of the coating. In addition, the sepiolite and the modified inorganic mineral additive can synergistically enhance the impact resistance of the coating.

Description

Technical Field

[0001] The present invention relates to the technical field of coatings, and in particular to an anti-corrosion and thermal insulation coating and a preparation method thereof. Background Art

[0002] In the industrial and construction fields, the anti-corrosion and thermal insulation properties of materials are extremely important, directly affecting the service life, energy consumption and safety of equipment. At present, most coatings use polymer resins as film-forming substances, such as epoxy resins, acrylic resins, polyurethanes, etc. The molecular structure of epoxy resins is rich in polar groups such as hydroxyl groups and ether bonds, which can have strong adhesion to substrates such as metals, allowing the coating to fit tightly to the surface of the substrate, forming a dense protective film. Taking the common bisphenol A epoxy resin as an example, after it reacts with the curing agent, it will form a three-dimensional network structure. This structure has extremely high density and can effectively prevent the penetration of corrosive media such as water vapor, oxygen, and electrolyte ions, so it can exhibit certain anti-corrosion properties.

[0003] However, in special use environments such as the ocean, the anti-corrosion performance of epoxy resin is difficult to meet the requirements. Moreover, traditional epoxy resin does not have thermal insulation properties. Therefore, it is of great significance to improve epoxy resin coatings and enhance their anti-corrosion and thermal insulation properties for their further application. Summary of the Invention

[0004] (1) Technical problems solved

[0005] In view of the deficiencies in the prior art, the present invention provides an anti-corrosion and thermal insulation coating and a preparation method thereof.

[0006] (2) Technical solution

[0007] An anti-corrosion and thermal insulation coating, comprising the following raw materials in parts by weight: 80-95 parts of epoxy acrylic resin, 2-5.5 parts of modified inorganic mineral additives, 5-10 parts of hollow glass microspheres, 3-5 parts of film-forming aid, 0.5-1.5 parts of defoaming agent, 0.5-1.5 parts of leveling agent, 1-3 parts of dispersant, 1-2 parts of wetting agent, and 10-20 parts of curing agent;

[0008] The modified inorganic mineral additive is sepiolite with a surface modified with polymer macromolecular substances.

[0009] As a further embodiment of the present invention, the preparation method of the modified inorganic mineral additive comprises the following steps:

[0010] Step 1: Add a silane coupling agent to deionized water and stir evenly, then increase the temperature to 50-60°C, stir and hydrolyze for 3-6 hours to form a modified liquid; disperse sepiolite in anhydrous ethanol to form a dispersion, then add the modified liquid to the dispersion and stir evenly, then increase the temperature to 70-80°C, keep the temperature for 6-9 hours, cool and discharge, separate the solid material, and obtain modified sepiolite;

[0011] Step 2: Add the modified sepiolite to N,N-dimethylformamide, ultrasonically disperse it to form a uniform dispersion, introduce nitrogen protection, then add an extender and a catalyst to the dispersion. After the addition is completed, heat it to 70-80°C, keep it warm and stir for 2-4 hours, then add 9,9-bis[4-(2,3-epoxypropoxyethoxy)phenyl]fluorene to the dispersion, and raise the temperature to 100-110°C. After keeping warm for 12-24 hours, cool it down and discharge it to obtain a modified inorganic mineral additive.

[0012] As a further embodiment of the present invention, in step 1, the silane coupling agent is 3-glycidyloxypropyltrimethoxysilane or 3-glycidyloxypropyltriethoxysilane.

[0013] As a further solution of the present invention, in step 2, the preparation method of the extending agent is as follows:

[0014] Add decamethyldihydrogen pentasiloxane to anhydrous ethanol and stir to mix, then add the acidifying agent. After the addition is completed, raise the temperature to 70-75°C and continue to add the platinum catalyst under stirring. After the addition is completed, keep warm and stir for 3-6 hours, evaporate to remove the solvent, cool and discharge, collect the product, and the extender can be obtained.

[0015] As a further embodiment of the present invention, the molar ratio of the decamethyldihydrogen pentasiloxane to the acidifying agent is 1:2.

[0016] As a further embodiment of the present invention, the acidifying agent is acrylic acid or methacrylic acid.

[0017] As a further embodiment of the present invention, in step 2, the catalyst is any one of tetrabutylammonium bromide, tetramethylammonium bromide, tetrabutylammonium hydrogen sulfate, and tetrabutylammonium chloride.

[0018] As a further embodiment of the present invention, in step 2, the mass ratio of the modified sepiolite, the extender and 9,9-bis[4-(2,3-epoxypropoxyethoxy)phenyl]fluorene is 1:3.5-6:2-4.

[0019] In the above technical solution, a silane coupling agent is first used to modify the surface of sepiolite so that the surface of the sepiolite carries epoxy functional groups to obtain modified sepiolite. Then, under the action of a catalyst, an extender connects 9,9-bis[4-(2,3-epoxypropoxyethoxy)phenyl]fluorene and sepiolite through the active carboxyl substituents at both ends of the structure. The 9,9-bis[4-(2,3-epoxypropoxyethoxy)phenyl]fluorene and the extender that do not participate in the reaction in the system can undergo a continuous ring-opening esterification polymerization reaction through the active functional groups at the ends of each other's structures, thereby forming an effect of in-situ polymerization of 9,9-bis[4-(2,3-epoxypropoxyethoxy)phenyl]fluorene and the extender on the surface of the sepiolite with the epoxy groups on the surface of the sepiolite as active initiation sites, thereby obtaining a polymer macromolecular substance with a surface modified with a fluorene-siloxane block structure, and obtaining a modified inorganic mineral additive.

[0020] The extender is prepared by using decamethyldihydrogen pentasiloxane and an acidifying agent as reactants. Under the action of a platinum catalyst, the Si-H in each structure reacts with the unsaturated olefinic functional group through a hydrosilylation reaction. By controlling the molar ratio of the two, the extender structure can contain active carboxyl substituents at both ends.

[0021] As a further embodiment of the present invention, the film-forming aid is at least one of propylene glycol butyl ether, dipropylene glycol monobutyl ether or ethylene glycol butyl ether acetate; the defoamer is NYK-065; the leveling agent is BYK-310 or BYK-315N; the dispersant is triethanolamine; the wetting agent is alkyl polyoxyethylene ether; and the curing agent is a diamine curing agent.

[0022] A method for preparing an anti-corrosion thermal insulation coating comprises the following steps:

[0023] The first step is to weigh each raw material according to the weight and set aside;

[0024] The second step is to add epoxy acrylic resin, modified inorganic mineral additives, hollow glass microspheres, film-forming aid, leveling agent, dispersant and wetting agent into a stirring tank, and mechanically stir and mix at a stirring rate of 500-1000 r / min for 20-30 minutes at room temperature to form a premix;

[0025] The third step is to add curing agent to the premix and stir for 10-20 minutes, then add defoaming agent and adjust the stirring rate to 200-300r / min. After continuing stirring for 20-30 minutes, stop stirring, let it stand for 1-2 hours, and discharge the material.

[0026] (3) Beneficial technical effects

[0027] The present invention prepares a modified inorganic mineral additive by modifying a polymer macromolecular substance on the surface of sepiolite. First, the structure of the polymer macromolecular substance contains a large number of hydroxyl functional groups generated by a ring-opening reaction, which can participate in the subsequent curing process of the epoxy acrylic resin, thereby realizing mutual entanglement and cross-linking with the epoxy acrylic resin. On the one hand, the density of the epoxy acrylic resin molecular chain is increased, and the density of the coating structure formed by curing is also increased, which can effectively prevent the penetration of corrosive media. This cross-linked structure can enable the sepiolite to exist in the coating structure in the form of a cross-linked core, greatly improving the interface compatibility between the sepiolite and the epoxy acrylic resin, and promoting the sepiolite to be uniformly dispersed in the coating. Furthermore, the layered chain structure of the sepiolite itself is utilized to extend the penetration path of the corrosive medium, thereby further enhancing the anti-corrosion effect of the coating. At the same time, the uniformly dispersed sepiolite can also produce a significant reinforcement effect, improving the impact performance of the coating. On the other hand, the polymer macromolecular structure also contains a fluorene-siloxane block structure, in which the rigid fluorene ring can improve the stability of the coating and further enhance the impact resistance of the coating. The presence of the siloxane chain segment can make the coating surface extremely hydrophobic, preventing the corrosive medium from adhering to the coating surface for a long time and continuously penetrating to cause corrosion.

[0028] The present invention adds hollow glass microspheres to form air cavities in the coating, thereby reducing the heat conduction path and improving the thermal insulation effect of the coating. DETAILED DESCRIPTION

[0029] To facilitate understanding of the present invention, the present invention will be described in more detail below. Preferred embodiments of the present invention are provided below. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and comprehensive understanding of the disclosure of the present invention.

[0030] Example 1

[0031] An anti-corrosion and thermal insulation coating, comprising the following raw materials in parts by weight: 80 parts of epoxy acrylic resin, 2 parts of modified inorganic mineral additives, 5 parts of hollow glass microspheres, 3 parts of propylene glycol butyl ether as a film-forming aid, 0.5 parts of NYK-065 as a defoaming agent, 0.5 parts of BYK-310 as a leveling agent, 1 part of triethanolamine as a dispersant, 1 part of alkyl polyoxyethylene ether as a wetting agent, and 10 parts of polyetheramine as a curing agent;

[0032] The preparation method of the anti-corrosion thermal insulation coating comprises the following steps:

[0033] The first step is to weigh each raw material according to the weight and set aside;

[0034] Step 2: Add epoxy acrylic resin, modified inorganic mineral additives, hollow glass microspheres, film-forming aid propylene glycol butyl ether, leveling agent BYK-310, dispersant triethanolamine and wetting agent alkyl polyoxyethylene ether into a stirred tank, and mechanically stir and mix at room temperature at a stirring rate of 500 r / min for 30 minutes to form a premix;

[0035] The third step is to add the curing agent polyetheramine to the premix, stir for 10 minutes, then add the defoaming agent NYK-065, adjust the stirring rate to 200r / min, continue stirring for 30 minutes, stop stirring, let it stand for 1 hour, and discharge the material.

[0036] Example 2

[0037] An anti-corrosion and thermal insulation coating, comprising the following raw materials in parts by weight: 85 parts of epoxy acrylic resin, 5 parts of modified inorganic mineral additives, 6 parts of hollow glass microspheres, 4 parts of dipropylene glycol monobutyl ether as a film-forming aid, 1 part of NYK-065 as a defoamer, 1 part of BYK-315N as a leveling agent, 2 parts of triethanolamine as a dispersant, 1.5 parts of alkyl polyoxyethylene ether as a wetting agent, and 15 parts of polyetheramine as a curing agent;

[0038] The preparation method of the anti-corrosion thermal insulation coating comprises the following steps:

[0039] The first step is to weigh each raw material according to the weight and set aside;

[0040] Step 2: Add epoxy acrylic resin, modified inorganic mineral additives, hollow glass microspheres, film-forming aid propylene glycol monobutyl ether, leveling agent BYK-315N, dispersant triethanolamine and wetting agent alkyl polyoxyethylene ether into a stirred tank, and mechanically stir and mix at room temperature at a stirring rate of 800 r / min for 25 minutes to form a premix;

[0041] The third step is to add the curing agent polyetheramine to the premix, stir for 15 minutes, then add the defoaming agent NYK-065, adjust the stirring rate to 300r / min, continue stirring for 25 minutes, stop stirring, let it stand for 1 hour, and discharge the material.

[0042] Example 3

[0043] An anti-corrosion and thermal insulation coating, comprising the following raw materials in parts by weight: 95 parts of epoxy acrylic resin, 5.5 parts of modified inorganic mineral additives, 10 parts of hollow glass microspheres, 5 parts of dipropylene glycol monobutyl ether as a film-forming aid, 1.5 parts of NYK-065 as a defoaming agent, 1.5 parts of BYK-315N as a leveling agent, 3 parts of triethanolamine as a dispersant, 2 parts of alkyl polyoxyethylene ether as a wetting agent, and 20 parts of polyetheramine as a curing agent;

[0044] The preparation method of the anti-corrosion thermal insulation coating comprises the following steps:

[0045] The first step is to weigh each raw material according to the weight and set aside;

[0046] Step 2: Add epoxy acrylic resin, modified inorganic mineral additives, hollow glass microspheres, film-forming aid ethylene glycol butyl ether acetate, leveling agent BYK-315N, dispersant triethanolamine and wetting agent alkyl polyoxyethylene ether into a stirred tank, and mechanically stir and mix at room temperature at a stirring rate of 1000 r / min for 20 minutes to form a premix;

[0047] The third step is to add the curing agent polyetheramine to the premix, stir for 20 minutes, then add the defoaming agent NYK-065, adjust the stirring rate to 300r / min, continue stirring for 20 minutes, stop stirring, let it stand for 2 hours, and discharge the material.

[0048] The modified inorganic mineral additives in the above examples are prepared by the following method:

[0049] Step 1: Add 1.2 g of 3-glycidyloxypropyltriethoxysilane to 50 mL of deionized water and stir evenly. Then, raise the temperature to 55°C and stir for hydrolysis for 4 hours to form a modified solution. Disperse 1.5 g of sepiolite in 60 mL of anhydrous ethanol to form a dispersion. Then, add the modified solution to the dispersion and stir evenly. Then, raise the temperature to 75°C and keep warm for 8 hours. Then, cool and discharge the material, separate the solid material, and obtain modified sepiolite.

[0050] Step 2: Add 1 g of modified sepiolite to N,N-dimethylformamide, ultrasonically disperse until a uniform dispersion is formed, introduce nitrogen protection, then add 5.5 g of extender and tetrabutylammonium bromide to the dispersion. After the addition is completed, heat to 75°C, keep stirring for 3 hours, then add 3 g of 9,9-bis[4-(2,3-epoxypropoxyethoxy)phenyl]fluorene to the dispersion, and raise the temperature to 110°C. After keeping warm for 16 hours, cool and discharge the material to obtain the modified inorganic mineral additive.

[0051] The preparation method of the extending agent is as follows:

[0052] Add 0.2 g of decamethyldihydrogen pentasiloxane to anhydrous ethanol and stir to mix. Then add 0.1 g of methacrylic acid. After the addition is complete, raise the temperature to 70°C and continue to add 0.01 g of platinum catalyst under stirring. After the addition is complete, keep warm and stir for 4 hours, evaporate to remove the solvent, cool and discharge, collect the product, and the extender can be obtained.

[0053] Comparative Example 1

[0054] An anti-corrosion and thermal insulation coating, comprising the following raw materials in parts by weight: 85 parts of epoxy acrylic resin, 5 parts of sepiolite, 6 parts of hollow glass microspheres, 4 parts of dipropylene glycol monobutyl ether as a film-forming aid, 1 part of NYK-065 as a defoamer, 1 part of BYK-315N as a leveling agent, 2 parts of triethanolamine as a dispersant, 1.5 parts of alkyl polyoxyethylene ether as a wetting agent, and 15 parts of polyetheramine as a curing agent;

[0055] The preparation method of the anti-corrosion thermal insulation coating comprises the following steps:

[0056] The first step is to weigh each raw material according to the weight and set aside;

[0057] Step 2: Add epoxy acrylic resin, sepiolite, hollow glass microspheres, film-forming aid propylene glycol monobutyl ether, leveling agent BYK-315N, dispersant triethanolamine, and wetting agent alkyl polyoxyethylene ether into a stirring tank, and mechanically stir and mix at room temperature at a stirring rate of 800 r / min for 25 minutes to form a premix;

[0058] The third step is to add the curing agent polyetheramine to the premix, stir for 15 minutes, then add the defoaming agent NYK-065, adjust the stirring rate to 300r / min, continue stirring for 25 minutes, stop stirring, let it stand for 1 hour, and discharge the material.

[0059] Comparative Example 2

[0060] An anti-corrosion and thermal insulation coating, comprising the following raw materials in parts by weight: 85 parts of epoxy acrylic resin, 6 parts of hollow glass microspheres, 4 parts of dipropylene glycol monobutyl ether as a film-forming aid, 1 part of NYK-065 as a defoamer, 1 part of BYK-315N as a leveling agent, 2 parts of triethanolamine as a dispersant, 1.5 parts of alkyl polyoxyethylene ether as a wetting agent, and 15 parts of polyetheramine as a curing agent;

[0061] The preparation method of the anti-corrosion thermal insulation coating comprises the following steps:

[0062] The first step is to weigh each raw material according to the weight and set aside;

[0063] Step 2: Add epoxy acrylic resin, hollow glass microspheres, film-forming aid propylene glycol monobutyl ether, leveling agent BYK-315N, dispersant triethanolamine, and wetting agent alkyl polyoxyethylene ether into a stirred tank, and mechanically stir and mix at room temperature at a stirring rate of 800 r / min for 25 minutes to form a premix;

[0064] The third step is to add the curing agent polyetheramine to the premix, stir for 15 minutes, then add the defoaming agent NYK-065, adjust the stirring rate to 300r / min, continue stirring for 25 minutes, stop stirring, let it stand for 1 hour, and discharge the material.

[0065] Performance Testing

[0066] The coatings in the examples and comparative examples were made into coating test samples, and various performance tests were performed. The results are recorded in Table 1:

[0067] Table 1

[0068]

[0069] The corrosion resistance test method is: immerse the sample in a sodium chloride solution with a mass concentration of 3.5%, observe the coating phenomenon after one week, and evaluate the corrosion resistance of the coating.

[0070] The impact resistance test method refers to the standard GB / T 10295-2008.

[0071] The thermal conductivity test method refers to the standard GB / T 1732-2020.

[0072] According to the test results, the coating with modified inorganic mineral additives has better impact resistance and corrosion resistance after curing.

[0073] After the modified inorganic mineral additives are replaced with unsurface-modified sepiolite, they cannot produce good compatibility with epoxy resin, achieve the effect of uniform dispersion, and cannot take advantage of the advantages of polymer macromolecules, resulting in a significant decrease in mechanical properties and corrosion resistance.

[0074] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0075] Based on the ideal embodiments of the present invention, and with reference to the above description, relevant personnel can make various changes and modifications without departing from the technical scope of the present invention. The technical scope of the present invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. An anti-corrosion and thermal insulation coating, characterized in that: The invention comprises the following raw materials in parts by weight: 80-95 parts of epoxy acrylic resin, 2-5.5 parts of modified inorganic mineral additive, 5-10 parts of hollow glass microspheres, 3-5 parts of film-forming aid, 0.5-1.5 parts of defoaming agent, 0.5-1.5 parts of leveling agent, 1-3 parts of dispersant, 1-2 parts of wetting agent and 10-20 parts of curing agent; The modified inorganic mineral additive is sepiolite with a surface modified with a polymer macromolecular substance; The preparation method of the modified inorganic mineral additive comprises the following steps: Step 1: Add a silane coupling agent to deionized water and stir evenly, then increase the temperature to 50-60°C, stir and hydrolyze for 3-6 hours to form a modified liquid; disperse sepiolite in anhydrous ethanol to form a dispersion, then add the modified liquid to the dispersion and stir evenly, then increase the temperature to 70-80°C, keep the temperature for 6-9 hours, cool and discharge, separate the solid material, and obtain modified sepiolite; Step 2: Add the modified sepiolite to N,N-dimethylformamide, ultrasonically disperse until a uniform dispersion is formed, introduce nitrogen protection, then add an extender and a catalyst to the dispersion, raise the temperature to 70-80°C, keep stirring for 2-4 hours, then add 9,9-bis[4-(2,3-epoxypropoxyethoxy)phenyl]fluorene to the dispersion, and raise the temperature to 100-110°C. After keeping the temperature for 12-24 hours, cool and discharge the material to obtain a modified inorganic mineral additive; In step 2, the preparation method of the extending agent is as follows: Add decamethyldihydrogen pentasiloxane to anhydrous ethanol and stir to mix, then add the acidifying agent. After the addition is complete, raise the temperature to 70-75°C and continue to add the platinum catalyst under stirring. After the addition is complete, keep the temperature and stir for 3-6 hours, evaporate the solvent, cool the material, collect the product, and the extender can be obtained; The molar ratio of the decamethyldihydrogen pentasiloxane to the acidifying agent is 1:2; The acidifying agent is acrylic acid or methacrylic acid.

2. The anti-corrosion and thermal insulation coating according to claim 1, characterized in that: In step 1, the silane coupling agent is 3-glycidyloxypropyltrimethoxysilane or 3-glycidyloxypropyltriethoxysilane.

3. The anti-corrosion and thermal insulation coating according to claim 1, characterized in that: In step 2, the catalyst is any one of tetrabutylammonium bromide, tetramethylammonium bromide, tetrabutylammonium hydrogen sulfate, and tetrabutylammonium chloride.

4. The anti-corrosion and thermal insulation coating according to claim 1, characterized in that: In step 2, the mass ratio of the modified sepiolite, the extender and 9,9-bis[4-(2,3-epoxypropoxyethoxy)phenyl]fluorene is 1:3.5-6:2-4.

5. The anti-corrosion and thermal insulation coating according to claim 1, characterized in that: The film-forming aid is at least one of propylene glycol butyl ether, dipropylene glycol monobutyl ether or ethylene glycol butyl ether acetate; the defoaming agent is NYK-065; the leveling agent is BYK-310 or BYK-315N; the dispersant is triethanolamine; the wetting agent is alkyl polyoxyethylene ether; and the curing agent is a diamine curing agent.

6. A method for preparing the anti-corrosion thermal insulation coating according to claim 1, characterized in that: The following steps are involved: The first step is to weigh each raw material according to the weight and set aside; The second step is to add epoxy acrylic resin, modified inorganic mineral additives, hollow glass microspheres, film-forming aid, leveling agent, dispersant and wetting agent into a stirring tank, and mechanically stir and mix at a stirring rate of 500-1000 r / min for 20-30 minutes at room temperature to form a premix; The third step is to add curing agent to the premix and stir for 10-20 minutes, then add defoaming agent and adjust the stirring rate to 200-300r / min. After continuing stirring for 20-30 minutes, stop stirring, let it stand for 1-2 hours, and discharge the material.

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