A water-based thermal insulation and anti-corrosion coating and preparation method thereof

Abstract

The present invention relates to the field of coating technology, discloses a water-based thermal insulation and anti-corrosion coating and its preparation method, the coating is formed by mixing with auxiliary materials such as modified hollow glass microspheres with water-based epoxy resin emulsion as a film-forming substance, wherein the modified hollow glass microspheres are prepared by modifying the surface of the hollow glass microspheres with a macromolecular chain containing polyphenylene sulfide, and the active groups contained in the macromolecular chain structure can participate in the curing process of the epoxy resin, which can not only greatly improve the cross-linking density of the coating and improve the structural density of the coating, but also improve the hydrophobicity of the coating surface through a large number of silicon-oxygen bonds and fluorine elements, forming a super-hydrophobic surface, greatly reducing the adhesion of corrosive media, thereby synergistically improving the anti-corrosion performance of the coating. In addition, the hollow glass microspheres can exist in the form of a network core, which can avoid the problem of reduced coating strength caused by agglomeration on the one hand, and can also form a uniform dispersion effect, effectively improving the thermal insulation performance of the coating.

Description

Technical Field

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

[0002] With the continuous development of modern industry, the industrial field has put forward higher requirements for equipment protection materials. Traditional thermal insulation materials have been unable to meet the needs of modern industry due to the potential corrosion hazards and complex construction. Water-based thermal insulation and anti-corrosion coatings can form a coating on the surface of the equipment and take advantage of the coating to achieve multiple improvements in the equipment. At present, the film-forming substances of coatings are mostly polymer materials, such as epoxy resins, acrylic resins and polyurethanes. The epoxy end groups in the epoxy resin molecules react with the active hydrogen in the curing agent to form a three-dimensional cross-linked network. This structure enables the coating to have an adhesion of more than 12MPa to the metal substrate, and this cross-linked network structure can prevent the penetration of corrosive media, thereby exhibiting certain anti-corrosion properties. Therefore, epoxy resin can be used as a film-forming substance for thermal insulation and anti-corrosion coatings.

[0003] However, in special operating environments such as the ocean, the anti-corrosion performance of epoxy resin coatings cannot actually meet the requirements, and they do not have thermal insulation properties. Therefore, performance modification of epoxy resin is of great significance for its further application in the coating field. Summary of the Invention

[0004] (1) Technical problems solved

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

[0006] (2) Technical solution

[0007] A water-based thermal insulation and anti-corrosion coating, comprising the following raw materials in parts by weight:

[0008] 45-65 parts of waterborne epoxy resin emulsion, 1-4.5 parts of modified hollow glass microspheres, 0.5-1 part of defoamer, 0.5-1 part of leveling agent, 1-2 parts of film-forming aid, 20-30 parts of deionized water, and 10-20 parts of curing agent;

[0009] The modified hollow glass microspheres are prepared by connecting macromolecular chains containing polyphenylene sulfide to the surfaces of the hollow glass microspheres.

[0010] As a further embodiment of the present invention, the preparation method of the modified hollow glass microspheres comprises the following steps:

[0011] Step 1: Add the hollow glass microspheres to toluene and disperse them evenly, then add the acid anhydride modification reagent. After the addition is complete, raise the temperature to 90-100°C, keep stirring for 2-6 hours, cool the material, separate the solid material, and obtain hollow glass microspheres containing carboxyl groups;

[0012] Step 2: adding the carboxyl-containing hollow glass microspheres to N,N-dimethylformamide, ultrasonically treating the mixture to form a uniform dispersion, then adding polyhydroxy-modified polyphenylene sulfide and a catalyst to the dispersion, raising the temperature to 100-120°C, keeping the temperature for 6-9 hours, cooling the mixture, discharging the mixture, and collecting the product to obtain a hollow glass microsphere intermediate;

[0013] Step 3: Disperse the hollow glass microsphere intermediate in 1,4-dioxane, then add 1H,1H,2H,2H-perfluorohexyltrichlorosilane and polyhydroxy-modified polyphenylene sulfide, stir evenly, then raise the temperature to 60-70°C, keep warm for 2-4 hours, continue to add the acid binding agent, and after the addition is completed, further raise the temperature to 80-90°C, continue stirring for 12-18 hours, cool and discharge the material to obtain the modified hollow glass microspheres.

[0014] As a further embodiment of the present invention, in step 1, the anhydride modification reagent is any one of maleic anhydride, succinic anhydride or glutaric anhydride.

[0015] As a further embodiment of the present invention, in step 2, the preparation method of the polyhydroxy-modified polyphenylene sulfide is as follows:

[0016] Add polyphenylene sulfide to dimethyl sulfoxide, raise the temperature to 180-190°C, stir until completely dissolved, then lower the temperature to 60-70°C, continue to add glycidol, and after addition, keep warm for 3-6 hours under continuous stirring, remove the solvent by rotary evaporation, and collect the product to obtain polyhydroxy-modified polyphenylene sulfide.

[0017] As a further embodiment of the present invention, the number average molecular weight of the polyphenylene sulfide is 10,000.

[0018] As a further embodiment of the present invention, in step 2, the catalyst is p-toluenesulfonic acid or aminosulfonic acid.

[0019] As a further embodiment of the present invention, in step three, the mass ratio of the hollow glass microsphere intermediate, 1H,1H,2H,2H-perfluorohexyltrichlorosilane and polyhydroxy-modified polyphenylene sulfide is 1:0.5-1:6-15.

[0020] As a further embodiment of the present invention, in step 3, the acid binding agent is triethylamine.

[0021] In the above technical solution, an anhydride modifier is first used to carboxylate the hollow glass microspheres to obtain hollow glass microspheres containing carboxyl groups. Then, under the action of a catalyst, the principle that hydroxyl groups can undergo a condensation reaction with carboxyl groups is utilized to further modify the hollow glass microspheres using polyhydroxy-modified polyphenylene sulfide to obtain hollow glass microsphere intermediates. Finally, polyhydroxy-modified polyphenylene sulfide is used as a polymerization monomer, 1H,1H,2H,2H-perfluorohexyltrichlorosilane is used as a polymerization monomer, and the hydroxyl substituents in each other's structures undergo a continuous and uninterrupted substitution reaction with the Si-Cl group, thereby achieving in situ polymerization of macromolecular chains containing polyphenylene sulfide on the surface of the hollow glass microspheres.

[0022] Among them, polyhydroxy-modified polyphenylene sulfide is prepared by using polyphenylene sulfide and glycidol as raw materials, and the thiol substituents in each other's structures can undergo a ring-opening reaction with the epoxy group under a high temperature environment.

[0023] As a further embodiment of the present invention, the defoaming agent is any one of BYK-070, BYK-088, BYK-065 or BYK-077; the leveling agent is any one of BYK-333, BYK-320, BYK-300 or BYK-388; the film-forming aid is propylene glycol butyl ether or dipropylene glycol monobutyl ether; and the curing agent is an acid anhydride curing agent.

[0024] A method for preparing a water-based thermal insulation and anti-corrosion coating comprises the following steps:

[0025] The first step is to weigh all the raw materials and complete the preparation;

[0026] The second step is to add the modified hollow glass microspheres and deionized water into a stirring tank, and ultrasonically disperse them uniformly to form a premix. Then, add water-based epoxy resin emulsion, leveling agent and film-forming aid to the premix. After the addition is completed, continue stirring and mix uniformly to form a precursor.

[0027] The third step is to add the curing agent and defoaming agent to the precursor, stir evenly, and let it stand to defoam.

[0028] (3) Beneficial technical effects

[0029] The present invention prepares modified hollow glass microspheres by modifying the macromolecular chain containing polyphenylene sulfide on the surface of hollow glass microspheres. The active groups contained in the macromolecular chain structure can participate in the curing process of epoxy resin. Therefore, a large amount of polyphenylene sulfide molecular chains and silicon-oxygen bonds, as well as strong hydrophobic fluorine elements, can be contained in the epoxy resin coating. It can not only greatly improve the cross-linking density of the coating and improve the structural density of the coating, but also improve the hydrophobicity of the coating surface by a large number of silicon-oxygen bonds and fluorine elements, forming a super-hydrophobic surface, greatly reducing the adhesion of corrosive media, thereby synergistically improving the anti-corrosion performance of the coating. In addition, in the cross-linked network, the hollow glass microspheres can exist in the form of a network core. On the one hand, it can avoid the problem of reduced coating strength caused by agglomeration, and can also form a uniform dispersion effect, effectively improving the thermal insulation performance of the coating. DETAILED DESCRIPTION

[0030] 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.

[0031] Example 1

[0032] A water-based thermal insulation and anti-corrosion coating, comprising the following raw materials in parts by weight:

[0033] 45 parts of waterborne epoxy resin emulsion E20, 1 part of modified hollow glass microspheres, 0.5 parts of defoaming agent BYK-070, 0.5 parts of leveling agent BYK-333, 1 part of film-forming aid propylene glycol butyl ether, 20 parts of deionized water, and 10 parts of curing agent phthalic anhydride;

[0034] The preparation method of the coating comprises the following steps:

[0035] The first step is to weigh all the raw materials and complete the preparation;

[0036] In the second step, the modified hollow glass microspheres and deionized water are added to a stirring tank and ultrasonically dispersed to form a premix. Then, water-based epoxy resin emulsion E20, leveling agent BYK-333 and film-forming aid propylene glycol butyl ether are added to the premix. After the addition is completed, stirring is continued to mix uniformly to form a precursor;

[0037] The third step is to add the curing agent phthalic anhydride and the defoaming agent BYK-070 to the precursor, stir evenly, and let it stand to defoam.

[0038] Example 2

[0039] A water-based thermal insulation and anti-corrosion coating, comprising the following raw materials in parts by weight:

[0040] 50 parts of waterborne epoxy resin emulsion E20, 4 parts of modified hollow glass microspheres, 0.8 parts of defoaming agent BYK-088, 0.6 parts of leveling agent BYK-320, 1.5 parts of film-forming aid dipropylene glycol monobutyl ether, 25 parts of deionized water, and 15 parts of curing agent phthalic anhydride;

[0041] The preparation method of the coating comprises the following steps:

[0042] The first step is to weigh all the raw materials and complete the preparation;

[0043] In the second step, the modified hollow glass microspheres and deionized water are added to a stirring tank and ultrasonically dispersed to form a premix. Then, water-based epoxy resin emulsion E20, leveling agent BYK-320 and film-forming aid dipropylene glycol monobutyl ether are added to the premix. After the addition is completed, stirring is continued to mix uniformly to form a precursor;

[0044] The third step is to add the curing agent phthalic anhydride and the defoaming agent BYK-088 to the precursor, stir evenly, and let it stand to defoam.

[0045] Example 3

[0046] A water-based thermal insulation and anti-corrosion coating, comprising the following raw materials in parts by weight:

[0047] 65 parts of waterborne epoxy resin emulsion E20, 4.5 parts of modified hollow glass microspheres, 1 part of defoamer BYK-065, 1 part of leveling agent BYK-300, 2 parts of film-forming aid dipropylene glycol monobutyl ether, 30 parts of deionized water, and 20 parts of curing agent phthalic anhydride;

[0048] The preparation method of the coating comprises the following steps:

[0049] The first step is to weigh all the raw materials and complete the preparation;

[0050] In the second step, the modified hollow glass microspheres and deionized water are added to a stirring tank and ultrasonically dispersed to form a premix. Then, water-based epoxy resin emulsion E20, leveling agent BYK-300 and film-forming aid dipropylene glycol monobutyl ether are added to the premix. After the addition is completed, stirring is continued to mix uniformly to form a precursor.

[0051] The third step is to add the curing agent phthalic anhydride and the defoaming agent BYK-065 to the precursor, stir evenly, and let it stand to defoam.

[0052] The modified hollow glass microspheres in the above examples and comparative examples were prepared by the following method:

[0053] Step 1: Add 2.4 g of hollow glass microspheres to toluene and disperse them evenly, then add 0.5 g of maleic anhydride. After the addition is complete, raise the temperature to 95°C, keep stirring for 4 hours, cool the material, separate the solid material, and obtain hollow glass microspheres containing carboxyl groups;

[0054] Step 2: Add 2 g of carboxyl-containing hollow glass microspheres to N,N-dimethylformamide and sonicate to form a uniform dispersion. Then, add 1.5 g of polyhydroxy-modified polyphenylene sulfide and 0.1 g of toluenesulfonic acid to the dispersion. After the addition is complete, raise the temperature to 110° C., keep warm for 8 hours, cool and discharge, collect the product, and obtain a hollow glass microsphere intermediate.

[0055] Step 3: Disperse 1.8 g of the hollow glass microsphere intermediate in 1,4-dioxane, then add 1.5 g of 1H,1H,2H,2H-perfluorohexyltrichlorosilane and 12 g of polyhydroxy-modified polyphenylene sulfide, stir evenly, then raise the temperature to 65 ° C, keep warm for 3 hours, and continue to add 1 g of triethylamine. After the addition is completed, the temperature is further raised to 85 ° C, and after continuous stirring for 16 hours, the temperature is cooled and discharged to obtain modified hollow glass microspheres.

[0056] The preparation method of polyhydroxy modified polyphenylene sulfide is as follows:

[0057] 12 g of polyphenylene sulfide with a number average molecular weight of 10,000 is added to dimethyl sulfoxide. After the addition is completed, the temperature is raised to 180°C and stirred until completely dissolved. Then the temperature is lowered to 65°C and 0.1 g of glycidol is added. After the addition is completed, the mixture is kept warm for 4 hours under continuous stirring, and the solvent is removed by rotary evaporation. The product is collected to obtain polyhydroxy-modified polyphenylene sulfide.

[0058] Comparative Example 1

[0059] A water-based thermal insulation and anti-corrosion coating, comprising the following raw materials in parts by weight:

[0060] 50 parts of waterborne epoxy resin emulsion E20, 4 parts of hollow glass microspheres, 0.8 parts of defoaming agent BYK-088, 0.6 parts of leveling agent BYK-320, 1.5 parts of film-forming aid dipropylene glycol monobutyl ether, 25 parts of deionized water, and 15 parts of curing agent phthalic anhydride;

[0061] The preparation method of the coating comprises the following steps:

[0062] The first step is to weigh all the raw materials and complete the preparation;

[0063] In the second step, hollow glass microspheres and deionized water are added to a stirring tank and ultrasonically dispersed to form a premix. Then, water-based epoxy resin emulsion E20, leveling agent BYK-320 and film-forming aid dipropylene glycol monobutyl ether are added to the premix. After the addition is completed, stirring is continued to mix uniformly to form a precursor;

[0064] The third step is to add the curing agent phthalic anhydride and the defoaming agent BYK-088 to the precursor, stir evenly, and let it stand to defoam.

[0065] Comparative Example 2

[0066] A water-based thermal insulation and anti-corrosion coating, comprising the following raw materials in parts by weight:

[0067] 50 parts of waterborne epoxy resin emulsion E20, 0.8 parts of defoaming agent BYK-088, 0.6 parts of leveling agent BYK-320, 1.5 parts of film-forming aid dipropylene glycol monobutyl ether, 25 parts of deionized water, and 15 parts of curing agent phthalic anhydride;

[0068] The preparation method of the coating comprises the following steps:

[0069] The first step is to weigh all the raw materials and complete the preparation;

[0070] Step 2: Add waterborne epoxy resin emulsion E20, leveling agent BYK-320 and film-forming aid dipropylene glycol monobutyl ether into deionized water, continue stirring and mix evenly to form a precursor;

[0071] The third step is to add the curing agent phthalic anhydride and the defoaming agent BYK-088 to the precursor, stir evenly, and let it stand to defoam.

[0072] Performance Testing

[0073] The coatings in the examples and comparative examples were made into coating samples that met the test specifications, and various performance tests were performed. The results are shown in the following table:

[0074]

[0075] The salt spray resistance is tested according to the standard GB / T 1771-1991;

[0076] The water contact angle is directly measured using a water contact angle meter;

[0077] Thermal conductivity is tested according to standard GB / T 1732-2020.

[0078] The test results show that the coating made with modified hollow glass microspheres has significantly better corrosion resistance and thermal insulation. Directly replacing them with unmodified hollow glass microspheres, on the one hand, loses its macromolecular chains, leading to compatibility issues with the epoxy resin substrate, making it impossible to disperse evenly, resulting in a significant decrease in thermal insulation. Furthermore, the loss of macromolecular chains has a significant negative impact on the corrosion resistance of the coating.

[0079] 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.

[0080] 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. A water-based thermal insulation and anti-corrosion coating, characterized in that: According to parts by weight, the following raw materials are included: 45-65 parts of waterborne epoxy resin emulsion, 1-4.5 parts of modified hollow glass microspheres, 0.5-1 part of defoamer, 0.5-1 part of leveling agent, 1-2 parts of film-forming aid, 20-30 parts of deionized water, and 10-20 parts of curing agent; The modified hollow glass microspheres are prepared by connecting macromolecular chains containing polyphenylene sulfide to the surface of the hollow glass microspheres; The preparation method of the modified hollow glass microspheres comprises the following steps: Step 1: Add the hollow glass microspheres to toluene and disperse them evenly, then add the acid anhydride modification reagent. After the addition is complete, raise the temperature to 90-100°C, keep stirring for 2-6 hours, cool the material, separate the solid material, and obtain hollow glass microspheres containing carboxyl groups; Step 2: adding the carboxyl-containing hollow glass microspheres to N,N-dimethylformamide, ultrasonically treating the mixture to form a uniform dispersion, then adding polyhydroxy-modified polyphenylene sulfide and a catalyst to the dispersion, raising the temperature to 100-120°C, keeping the temperature for 6-9 hours, cooling the mixture, discharging the mixture, and collecting the product to obtain a hollow glass microsphere intermediate; Step 3: Disperse the hollow glass microsphere intermediate in 1,4-dioxane, then add 1H,1H,2H,2H-perfluorohexyltrichlorosilane and polyhydroxy-modified polyphenylene sulfide, stir evenly, then raise the temperature to 60-70°C, keep warm for 2-4 hours, continue to add the acid binding agent, and after the addition is completed, further raise the temperature to 80-90°C, continue stirring for 12-18 hours, cool and discharge the material to obtain the modified hollow glass microspheres; The preparation method of the polyhydroxy-modified polyphenylene sulfide is as follows: Add polyphenylene sulfide to dimethyl sulfoxide, raise the temperature to 180-190°C, stir until completely dissolved, then lower the temperature to 60-70°C, continue to add glycidol, and after addition, keep warm for 3-6 hours under continuous stirring, remove the solvent by rotary evaporation, and collect the product to obtain polyhydroxy-modified polyphenylene sulfide.

2. The water-based thermal insulation and anti-corrosion coating according to claim 1, characterized in that: In step 1, the anhydride modification reagent is any one of maleic anhydride, succinic anhydride or glutaric anhydride.

3. The water-based thermal insulation and anti-corrosion coating according to claim 1, characterized in that: The number average molecular weight of the polyphenylene sulfide is 10,000.

4. The water-based thermal insulation and anti-corrosion coating according to claim 1, characterized in that: In step 2, the catalyst is p-toluenesulfonic acid or aminosulfonic acid.

5. The water-based thermal insulation and anti-corrosion coating according to claim 1, characterized in that: In step 3, the mass ratio of the hollow glass microsphere intermediate, 1H,1H,2H,2H-perfluorohexyltrichlorosilane and polyhydroxy-modified polyphenylene sulfide is 1:0.5-1:6-15.

6. The water-based thermal insulation and anti-corrosion coating according to claim 1, characterized in that: In step 3, the acid binding agent is triethylamine.

7. The water-based thermal insulation and anti-corrosion coating according to claim 1, characterized in that: The defoaming agent is any one of BYK-070, BYK-088, BYK-065 or BYK-077; the leveling agent is any one of BYK-333, BYK-320, BYK-300 or BYK-388; the film-forming aid is propylene glycol butyl ether or dipropylene glycol monobutyl ether; and the curing agent is an acid anhydride curing agent.

8. A method for preparing the water-based thermal insulation and anti-corrosion coating according to claim 1, characterized in that: The following steps are involved: The first step is to weigh all the raw materials and complete the preparation; The second step is to add the modified hollow glass microspheres and deionized water into a stirring tank, and ultrasonically disperse them uniformly to form a premix. Then, add water-based epoxy resin emulsion, leveling agent and film-forming aid to the premix. After the addition is completed, continue stirring and mix uniformly to form a precursor. The third step is to add the curing agent and defoaming agent to the precursor, stir evenly, and let it stand to defoam.

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