Water-based heat-preservation heat-insulation anticorrosive paint and preparation method thereof

Abstract

The invention relates to the technical field of coatings, and discloses a water-based heat-preservation heat-insulation anticorrosive coating and a preparation method thereof.The water-based heat-preservation heat-insulation anticorrosive coating is formed by mixing water-based epoxy resin emulsion serving as a film-forming substance with modified hollow glass beads and other auxiliary materials; wherein the modified hollow glass beads are prepared by modifying the surfaces of the hollow glass beads with macromolecular chains containing polyphenylene sulfide, and active groups contained in the macromolecular chain structure can participate in the curing process of epoxy resin, so that the crosslinking density of the coating can be greatly improved, the structural density of the coating is improved, and the service life of the coating is prolonged. And the hydrophobicity of the surface of the coating can be improved through a large number of silicon-oxygen bonds and fluorine elements, a super-hydrophobic surface is formed, attachment of a corrosive medium is greatly reduced, and therefore the corrosion resistance of the coating is cooperatively improved. Besides, the hollow glass beads can exist in the form of a network core, on one hand, the problem that the strength of the coating is reduced due to agglomeration can be avoided, a uniform dispersion effect can be formed, and the heat preservation and heat insulation performance of the coating is effectively improved.

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 difficult 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 undergo a ring-opening reaction 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 showing 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 use environments such as the ocean, the anti-corrosion performance of epoxy resin coatings does not actually meet the requirements, and it does not have thermal insulation properties. Therefore, performance modification of epoxy resin is of great significance for its further application in the coatings field. Summary of the invention

[0004] 1. Technical issues to be resolved 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.

[0005] (II) Technical solution A water-based thermal insulation and anti-corrosion coating, comprising the following raw materials in parts by weight: 45-65 parts of waterborne epoxy resin emulsion, 1-4.5 parts of modified hollow glass microspheres, 0.5-1 parts of defoaming agent, 0.5-1 parts 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 on the surface of the hollow glass microspheres.

[0006] As a further embodiment of the present invention, the method for preparing 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 anhydride modification reagent, after the addition, raise the temperature to 90-100°C, keep stirring for 2-6 hours, cool down and discharge the material, separate the solid material, and obtain the hollow glass microspheres containing carboxyl groups; Step 2: Add carboxyl-containing hollow glass microspheres into N,N-dimethylformamide, and ultrasonicate until a homogeneous dispersion is formed. Then, add polyhydroxy-modified polyphenylene sulfide and a catalyst to the dispersion. After adding, raise the temperature to 100 - 120 °C, keep warm for 6 - 9 h, then cool down and discharge the material, collect the product to obtain the 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 h, continue to add an acid-binding agent. After adding, further raise the temperature to 80 - 90 °C, continuously stir for 12 - 18 h, then cool down and discharge the material to obtain the modified hollow glass microspheres.

[0007] As a further aspect of the present invention, in Step 1, the anhydride modification reagent is any one of maleic anhydride, succinic anhydride, or glutaric anhydride.

[0008] As a further aspect of the present invention, in Step 2, the preparation method of the polyhydroxy-modified polyphenylene sulfide is as follows: Add polyphenylene sulfide into dimethyl sulfoxide. After adding, raise the temperature to 180 - 190 °C, stir until completely dissolved, then lower the temperature to 60 - 70 °C, continue to add glycidyl. After adding, carry out heat preservation treatment for 3 - 6 h under continuous stirring, then remove the solvent by rotary evaporation, collect the product to obtain the polyhydroxy-modified polyphenylene sulfide.

[0009] As a further aspect of the present invention, the number-average molecular weight of the polyphenylene sulfide is 10,000.

[0010] As a further aspect of the present invention, in Step 2, the catalyst is p-toluenesulfonic acid or sulfamic acid.

[0011] As a further aspect of the present invention, 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.

[0012] As a further aspect of the present invention, in Step 3, the acid-binding agent is triethylamine.

[0013] In the above technical solution, first, an anhydride modifier is used to carboxylate modify hollow glass microspheres to obtain carboxyl-containing hollow glass microspheres. Then, under the action of a catalyst, based on the principle that hydroxyl groups can undergo a condensation reaction with carboxyl groups, polyhydroxy-modified polyphenylene sulfide is used to further modify them to obtain an intermediate of hollow glass microspheres. Finally, using polyhydroxy-modified polyphenylene sulfide and 1H,1H,2H,2H-perfluorohexyl trichlorosilane as polymerization monomers, continuous substitution reactions occur between the hydroxyl substituents and Si-Cl groups in their respective structures, realizing in-situ polymerization of macromolecular chains containing polyphenylene sulfide on the surface of hollow glass microspheres.

[0014] Among them, polyhydroxy-modified polyphenylene sulfide is prepared from polyphenylene sulfide and glycidyl as raw materials, and the mercapto substituents in their respective structures can undergo a ring-opening reaction with epoxy groups under high-temperature conditions.

[0015] As a further solution of the present invention, the defoamer 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 auxiliary agent is propylene glycol monobutyl ether or dipropylene glycol monobutyl ether; the curing agent is an acid anhydride curing agent.

[0016] A preparation method of a waterborne heat-insulating and anticorrosive coating includes the following steps: First step: Weigh and prepare all raw materials to complete the preparation. Second step: Add the modified hollow glass microspheres and deionized water into a stirring kettle, ultrasonically disperse them evenly to form a premix. Then, add a waterborne epoxy resin emulsion, a leveling agent and a film-forming auxiliary agent to the premix. After adding, continue to stir and mix evenly to form a precursor. Third step: Add the curing agent and the defoamer to the precursor, stir evenly, and then stand still to defoam, and that's it.

[0017] (III) Beneficial technical effects The present invention obtains modified hollow glass microspheres by modifying the macromolecular chains 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, so 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, which can not only greatly improve the crosslinking density of the coating, but also improve the structural density of the coating. The hydrophobicity of the coating surface can be improved by a large amount of silicon oxygen bonds and fluorine elements, forming a super-hydrophobic surface, greatly reducing the attachment 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, 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. DETAILED DESCRIPTION

[0018] In order to facilitate the understanding of the present invention, the present invention will be described more fully below. Preferred embodiments of the present invention are given below. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0019] Example 1

[0020] A water-based thermal insulation and anti-corrosion coating, comprising the following raw materials in parts by weight: 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; The preparation method of the coating comprises the following steps: The first step is to weigh and prepare all the raw materials to complete the material preparation; Step 2: Add the modified hollow glass microspheres and deionized water into a stirring kettle, disperse them uniformly by ultrasonication to form a premix, then add waterborne epoxy resin emulsion E20, leveling agent BYK-333 and film-forming aid propylene glycol butyl ether into the premix, continue stirring after addition, mix uniformly to form a precursor; The third step is to add curing agent phthalic anhydride and defoaming agent BYK-070 to the precursor, stir evenly, and let it stand to defoam.

[0021] Example 2

[0022] A water-based thermal insulation and anti-corrosion coating, comprising the following raw materials in parts by weight: 50 parts of waterborne epoxy resin emulsion E20, 4 parts of modified hollow glass microspheres, 0.8 part of defoamer BYK-088, 0.6 part of leveling agent BYK-320, 1.5 parts of film-forming auxiliary dipropylene glycol monobutyl ether, 25 parts of deionized water, 15 parts of curing agent phthalic anhydride; The preparation method of the coating comprises the following steps: First step, weigh and prepare all raw materials to complete the preparation; Second step, add the modified hollow glass microspheres and deionized water into a stirring kettle, disperse them evenly by ultrasonic wave to form a premix. Then, add the waterborne epoxy resin emulsion E20, leveling agent BYK-320 and film-forming auxiliary dipropylene glycol monobutyl ether into the premix. After adding, continue to stir and mix evenly to form a precursor; Third step, add the curing agent phthalic anhydride and defoamer BYK-088 into the precursor, stir evenly, and then stand for defoaming to obtain the product.

[0023] Example 3

[0024] A waterborne heat-insulating and anticorrosive coating, by weight, comprises the following raw materials: 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 auxiliary dipropylene glycol monobutyl ether, 30 parts of deionized water, 20 parts of curing agent phthalic anhydride; The preparation method of the coating comprises the following steps: First step, weigh and prepare all raw materials to complete the preparation; Second step, add the modified hollow glass microspheres and deionized water into a stirring kettle, disperse them evenly by ultrasonic wave to form a premix. Then, add the waterborne epoxy resin emulsion E20, leveling agent BYK-300 and film-forming auxiliary dipropylene glycol monobutyl ether into the premix. After adding, continue to stir and mix evenly to form a precursor; Third step, add the curing agent phthalic anhydride and defoamer BYK-065 into the precursor, stir evenly, and then stand for defoaming to obtain the product.

[0025] The modified hollow glass microspheres in the above examples and comparative examples are prepared by the following method: Step one, add 2.4 g of hollow glass microspheres into toluene, disperse them evenly, then add 0.5 g of maleic anhydride. After adding, raise the temperature to 95 °C, keep stirring for 4 h, then cool down and discharge, and separate the solid material to obtain carboxyl-containing hollow glass microspheres; Step 2: Add 2 g of carboxyl-containing hollow glass microspheres into N,N-dimethylformamide, and ultrasonically treat until a homogeneous dispersion is formed. Then, add 1.5 g of polyhydroxy-modified polyphenylene sulfide and 0.1 g of p-toluenesulfonic acid to the dispersion. After adding, raise the temperature to 110 °C, keep the temperature for 8 h, then cool down and discharge the material, and collect the product to obtain the hollow glass microsphere intermediate; 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 the temperature for 3 h, then continue to add 1 g of triethylamine. After adding, further raise the temperature to 85 °C, continuously stir for 16 h, then cool down and discharge the material to obtain the modified hollow glass microspheres.

[0026] The preparation method of the polyhydroxy-modified polyphenylene sulfide is as follows: Add 12 g of polyphenylene sulfide with a number average molecular weight of 10,000 into dimethyl sulfoxide. After adding, raise the temperature to 180 °C and stir until completely dissolved. Then, lower the temperature to 65 °C, continue to add 0.1 g of glycidyl. After adding, keep the temperature for 4 h under continuous stirring, then remove the solvent by rotary evaporation, and collect the product to obtain the polyhydroxy-modified polyphenylene sulfide.

[0027] Comparative Example 1 An aqueous heat-insulating, heat-preserving and anticorrosive coating, by weight, comprises the following raw materials: 50 parts of aqueous epoxy resin emulsion E20, 4 parts of hollow glass microspheres, 0.8 part of defoamer BYK-088, 0.6 part of leveling agent BYK-320, 1.5 parts of film-forming auxiliary agent dipropylene glycol monobutyl ether, 25 parts of deionized water, 15 parts of curing agent phthalic anhydride; The preparation method of the coating comprises the following steps: First step: Weigh and prepare all the raw materials to complete the preparation; Second step: Add the hollow glass microspheres and deionized water into a stirring kettle, ultrasonically disperse evenly to form a premix. Then, add the aqueous epoxy resin emulsion E20, leveling agent BYK-320 and film-forming auxiliary agent dipropylene glycol monobutyl ether to the premix. After adding, continue to stir and mix evenly to form a precursor; Third step: Add the curing agent phthalic anhydride and defoamer BYK-088 to the precursor, stir evenly, and then stand for defoaming.

[0028] Comparative Example 2 An aqueous heat-insulating, heat-preserving and anticorrosive coating, by weight, comprises the following raw materials: 50 parts of waterborne epoxy resin emulsion E20, 0.8 part of defoamer BYK-088, 0.6 part of leveling agent BYK-320, 1.5 parts of film-forming auxiliary dipropylene glycol monobutyl ether, 25 parts of deionized water, and 15 parts of curing agent phthalic anhydride; The preparation method of the coating comprises the following steps: First step, weigh and prepare all raw materials to complete the preparation; Second step, add the waterborne epoxy resin emulsion E20, leveling agent BYK-320 and film-forming auxiliary dipropylene glycol monobutyl ether into deionized water. After adding, continue to stir and mix evenly to form a precursor; Third step, add the curing agent phthalic anhydride and defoamer BYK-088 into the precursor, stir evenly, and then stand for defoaming to obtain the product.

[0029] Performance test Make the coatings in the examples and comparative examples into various coating samples that meet the test specifications, and conduct various performance tests. The results are shown in the following table:

[0030] Among them, the salt spray resistance performance is tested according to the standard GB / T 1771-1991; The water contact angle is directly measured by a water contact angle measuring instrument; The thermal conductivity is tested according to the standard GB / T 1732-2020.

[0031] According to the test results, it can be known that the coating formed by adding the modified hollow glass microspheres has significantly better corrosion resistance and heat preservation effect. After directly replacing it with the unmodified hollow glass microspheres, on the one hand, due to the loss of the macromolecular chain, compatibility problems occur between it and the epoxy resin substrate, resulting in uneven dispersion, so the heat preservation effect decreases significantly. Moreover, after losing the macromolecular chain, it significantly has a more serious negative impact on the corrosion resistance of the coating.

[0032] In the description of this specification, the descriptions of reference terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in connection 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 a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0033] Based on the inspiration of the ideal embodiments of the present invention, through the above description, relevant personnel can completely make various changes and modifications without departing from the technical idea of this invention. The technical scope of this invention is not limited to the content in the specification, and the technical scope must be determined according to the scope of the claims.

Claims

1. An aqueous heat-insulating and anticorrosive coating, characterized in that, By weight parts, it includes the following raw materials: 45 - 65 parts of aqueous 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 auxiliary, 20 - 30 parts of deionized water, 10 - 20 parts of curing agent; The modified hollow glass microspheres are prepared by connecting macromolecular chains containing polyphenylene sulfide on the surface of hollow glass microspheres.

2. The water-based heat-insulating and anticorrosive coating according to claim 1, wherein The preparation method of the modified hollow glass microspheres includes the following steps: Step 1: Add hollow glass microspheres into toluene, disperse evenly, then add acid anhydride modification reagent. After adding, raise the temperature to 90 - 100 °C, keep warm and stir for 2 - 6 h, then cool down and discharge, separate the solid material to obtain carboxyl-containing hollow glass microspheres; Step 2: Add the carboxyl-containing hollow glass microspheres into N,N-dimethylformamide, ultrasonically treat until a uniform dispersion is formed, then add polyhydroxy-modified polyphenylene sulfide and catalyst to the dispersion. After adding, raise the temperature to 100 - 120 °C, keep warm for 6 - 9 h, then cool down and discharge, collect the product to obtain 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 h, then continue to add acid-binding agent. After adding, further raise the temperature to 80 - 90 °C, continuously stir for 12 - 18 h, then cool down and discharge to obtain the modified hollow glass microspheres.

3. The water-based heat-insulating and anti-corrosive coating according to claim 2, characterized in that, In Step 1, the acid anhydride modification reagent is any one of maleic anhydride, succinic anhydride or glutaric anhydride.

4. The water-based heat-insulating and anti-corrosive coating according to claim 2, wherein, In Step 2, the preparation method of the polyhydroxy-modified polyphenylene sulfide is as follows: Add polyphenylene sulfide into dimethyl sulfoxide. After adding, raise the temperature to 180 - 190 °C, stir until completely dissolved, then lower the temperature to 60 - 70 °C, continue to add glycidyl. After adding, keep warm for 3 - 6 h under continuous stirring, then rotary evaporate to remove the solvent, collect the product to obtain polyhydroxy-modified polyphenylene sulfide.

5. The water-based heat-insulating and anti-corrosive coating according to claim 2, characterized in that, The number average molecular weight of the polyphenylene sulfide is 10,000.

6. The water-based heat-insulating and anti-corrosive coating according to claim 2, wherein, In Step 2, the catalyst is p-toluenesulfonic acid or sulfamic acid.

7. The water-based heat-insulating and anti-corrosion coating according to claim 2, wherein 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.

8. The water-based heat-insulating and anti-corrosive coating according to claim 2, wherein In Step 3, the acid-binding agent is triethylamine.

9. The water-based heat-insulating and anti-corrosive coating according to claim 1, wherein The defoamer 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 auxiliary is propylene glycol butyl ether or dipropylene glycol monobutyl ether; the curing agent is an acid anhydride curing agent.

10. A preparation method of the waterborne heat-insulating and anti-corrosion coating as described in claim 1, characterized in that, It includes the following steps: The first step: Weigh and prepare all raw materials to complete the preparation. Step 2: Add the modified hollow glass microspheres and deionized water into a stirring kettle, disperse them evenly by ultrasonic waves to form a premix. Then, add a waterborne epoxy resin emulsion, a leveling agent and a film-forming aid into the premix. After adding, continue stirring and mixing evenly to form a precursor material; Step 3: Add a curing agent and an antifoaming agent into the precursor material, stir evenly, and then let it stand for defoaming, and that's it.

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