A protective coating on the inner surface of water treatment equipment and a preparation method thereof

Abstract

This application relates to the technical field of coatings and specifically discloses a protective coating for the inner surface of water treatment equipment and its preparation method. The protective coating for the inner surface of water treatment equipment disclosed in this application specifically comprises the following components in parts by weight: 50-60 parts epoxy resin, 5-10 parts curing agent, 1-3 parts toughening agent, 4-8 parts modified filler, 3-7 parts protective agent, 0.5-1.5 parts dispersant, and 20-26 parts solvent; the modified filler is prepared from a vegetable oil polyol, gum arabic, a catalyst, a nanofiller, and an aliphatic isocyanate; the protective agent is prepared from corn oil, castor oil polyol, adipic acid, acrylic anhydride, and a catalyst. The protective coating for the inner surface of water treatment equipment prepared using the technical solution of this application has good impact resistance and strong acid, alkali, and salt spray resistance.

Description

Technical Field

[0001] The present application relates to the technical field of coatings, and in particular to a protective coating for the inner surface of water treatment equipment and a preparation method thereof. Background Art

[0002] With increasingly stringent water quality requirements in industrial production, water treatment has become an essential component. However, in practice, many water treatment facilities have been found to experience severe internal wall corrosion after a period of operation. Two common approaches are currently used: regularly replacing damaged components or extending the life of equipment by spraying or painting with conventional paint. The former is expensive, while the latter is relatively cost-effective but, due to the paint's inherent poor weather resistance, it doesn't fundamentally address the problem. This not only increases maintenance costs but also impacts system operation.

[0003] Therefore, the development of new and efficient anti-corrosion coatings is of great significance to improving water treatment efficiency. Summary of the Invention

[0004] In order to solve the above technical problems, the present application provides a protective coating on the inner surface of water treatment equipment and a preparation method thereof.

[0005] The present application provides a protective coating for the inner surface of water treatment equipment, specifically comprising the following components in parts by weight: 50-60 parts of epoxy resin, 5-10 parts of curing agent, 1-3 parts of toughening agent, 4-8 parts of modified filler, 3-7 parts of protective agent, 0.5-1.5 parts of dispersant, and 20-26 parts of solvent;

[0006] The modified filler is prepared by adding vegetable oil polyol, gum arabic, a catalyst, and a nanofiller to water, mixing them evenly, heating the mixture to 50-70° C., and stirring for 30-90 minutes; then adding aliphatic isocyanate and stirring for 10-20 minutes, stirring and mixing, drying and solidifying, and grinding the mixture.

[0007] The weight ratio of water, vegetable oil polyol, gum arabic, catalyst, nanofiller and aliphatic isocyanate is 220-260:90-110:5-15:0.6-1.2:20-30:40-80;

[0008] The protective agent is prepared by: mixing corn oil, castor oil polyol, and adipic acid at 40-60° C., adding acrylic anhydride and a catalyst, and stirring for 60-90 minutes to obtain the protective agent;

[0009] The weight ratio of the corn oil, castor oil polyol, adipic acid, acrylic anhydride and catalyst is 5-10:50-60:30-40:4-8:0.2-0.7.

[0010] In the technical solution of this application, epoxy resin, as the main film-forming substance, has excellent corrosion resistance and adhesion, and can form a dense protective film that effectively isolates water, oxygen, and other corrosive substances, thereby protecting the inner surface of water treatment equipment. The curing agent chemically reacts with the epoxy resin, causing it to solidify into a hard coating, improving the coating's wear resistance and durability. The addition of a toughening agent can improve the coating's flexibility and impact resistance, preventing the coating from cracking or flaking when subjected to external forces. Modified fillers can enhance the coating's overall performance, improving hardness, wear resistance, scratch resistance, etc., while also reducing costs. The protective agent can further improve the coating's corrosion resistance and extend the service life of the equipment. The function of the dispersant is to evenly disperse the various components in the coating, preventing the coating from sedimentation or stratification during storage and use, and ensuring the uniformity and stability of the coating. The solvent mainly dissolves and dilutes the coating components, facilitating the construction and application of the coating. These components work together to ensure the coating's excellent performance and long-term protective effect in the preparation of protective coatings for the inner surfaces of water treatment equipment.

[0011] This application utilizes vegetable oil polyols, gum arabic, a catalyst, nanofillers, and aliphatic isocyanates to prepare modified fillers. The vegetable oil polyols, as a matrix material, provide excellent flexibility, water resistance, and impact resistance, thereby protecting the inner surface of water treatment equipment from corrosion. The gum arabic acts as a thickener and stabilizer, helping to improve the filler's film-forming properties and the coating's adhesion and durability, thereby enhancing corrosion resistance. The nanofillers enhance the coating's mechanical properties and corrosion resistance, while also improving its hardness, wear resistance, and scratch resistance. The aliphatic isocyanate acts as a crosslinking agent in the modified filler, reacting with the vegetable oil polyol to form a network structure, improving the coating's weather resistance and chemical resistance.

[0012] This application utilizes corn oil, castor oil polyol, adipic acid, acrylic anhydride, and a catalyst to prepare a protective agent. The introduction of corn oil and castor oil polyol as primary raw materials further enhances the coating's flexibility and water resistance, thereby improving its corrosion resistance. The catalyst causes a chemical reaction between the adipic acid and acrylic anhydride, forming a cross-linked structure. This cross-linked structure, in conjunction with the corn oil and castor oil polyol, significantly improves the coating's hardness and impact resistance, while also enhancing its corrosion resistance.

[0013] Preferably, the protective coating on the inner surface of the water treatment equipment specifically comprises the following components in parts by weight: 52-58 parts of epoxy resin, 6-9 parts of curing agent, 1.5-2.5 parts of toughening agent, 5-7 parts of modified filler, 4-6 parts of protective agent, 0.7-1.2 parts of dispersant, and 22-24 parts of solvent.

[0014] Preferably, in the preparation method of the modified filler, the weight ratio of the water, vegetable oil polyol, gum arabic, catalyst, nanofiller, and aliphatic isocyanate is 230-250:95-105:7-12:0.8-1.0:22-28:50-70.

[0015] Preferably, in the preparation method of the modified filler, the vegetable oil polyol is selected from one or more of castor oil, palm oil polyol, olive oil polyol, rapeseed oil polyol, soybean oil polyol, linseed oil polyol, peanut oil polyol, and corn oil polyol; the catalyst is selected from one or more of triethylamine, triethanolamine, dibutyltin dilaurate, and stannous octoate; and the nanofiller is selected from one or more of sodium lignin sulfonate, sodium silicate, magnesium carbonate, talc, and kaolin.

[0016] Preferably, in the preparation method of the protective agent, the weight ratio of the corn oil, castor oil polyol, adipic acid, acrylic anhydride, and catalyst is 6-9:52-58:32-37:5-7:0.3-0.6.

[0017] Preferably, in the preparation method of the protective agent, the catalyst is selected from one or more of acetate, monobutyltin triisooctoate, dioctyltin oxide, tetrabutyl titanate, isopropyl titanate, and N-hydroxysuccinimide.

[0018] Preferably, the epoxy resin is selected from one or more of E44 epoxy resin and E51 epoxy resin; the curing agent is selected from one or more of ethylenediamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine, and diethylaminopropylamine; and the solvent is selected from one or more of methanol, ethanol, or xylene.

[0019] Preferably, the toughening agent is composed of a mixture of hydroxy silicone oil and propylene glycol block polyether in a weight ratio of 2-4:0.5-1.5.

[0020] In a specific embodiment, the weight ratio of the hydroxy silicone oil to the propylene glycol block polyether can be: 2:0.5, 2:1, 2:1.5, 3:0.5, 3:1, 3:1.5, 4:0.5, 4:1, 4:1.5.

[0021] Preferably, the propylene glycol block polyether has an average molecular weight of 1850-2650 and a viscosity at 25° C. of 310-475 cps.

[0022] In a specific embodiment, the performance parameters of the propylene glycol block polyether are: model L43, molecular weight of 1850, and viscosity of 310 cps at 25°C.

[0023] In a specific embodiment, the performance parameters of the propylene glycol block polyether are: model L44, molecular weight of 2200, and viscosity at 25° C. of 440 cps.

[0024] In a specific embodiment, the performance parameters of the propylene glycol block polyether are: model L63, molecular weight of 2650, and viscosity at 25° C. of 475 cps.

[0025] Experimental analysis shows that the type of toughening agent has a great influence on the performance of protective coatings. Through multiple experiments, this application found that when a toughening agent is composed of a mixture of hydroxy silicone oil and propylene glycol block polyether with an average molecular weight of 1850-2650 and a viscosity of 310-475 cps at a weight ratio of 2-4:0.5-1.5, the corrosion resistance of the protective coating can be further improved.

[0026] In a second aspect, the present application provides a method for preparing the protective coating on the inner surface of the water treatment equipment, which is characterized by specifically comprising the following steps in sequence:

[0027] Epoxy resin, toughening agent, protective agent and dispersant are dispersed in a solvent by weight, and then the modified filler is added under stirring at 3000-6000 rpm and high-speed dispersion is continued for 20-40 minutes; then the curing agent is added and stirred at high speed for 90-150 minutes to obtain the coating, which is sprayed or brushed onto the surface of the equipment to form a protective coating.

[0028] In summary, the technical solution of this application has the following effects:

[0029] In the technical solution of the present application, epoxy resin, curing agent, toughening agent, modified filler, protective agent, dispersant and solvent are used as raw materials to prepare a protective coating, which together ensure the excellent performance and long-term protective effect of the coating, so that the coating has good impact resistance, and is highly resistant to acid and alkali and salt spray. DETAILED DESCRIPTION

[0030] The present application is further described in detail below in conjunction with examples, comparative examples and performance testing experiments. These examples should not be construed as limiting the scope of protection claimed in this application.

[0031] Palm oil polyol was purchased from Shandong Moore Chemical Co., Ltd.; castor oil polyol (BASF BASFSovermol805) was purchased from Shanghai Wandao Chemical Co., Ltd.; gum arabic (CAS No.: 9000-01-5) was purchased from Sigma-Aldrich; talc powder (model YD-224, 400 mesh fineness) was purchased from Tianjin Yandong Mineral Products Co., Ltd.; hydroxy silicone oil (CAS No.: 70131-67-8, average Mn ~ 500, viscosity ~ 25 cSt) was purchased from Aladdin, ethyl silicone oil (CAS No.: 63148-61-8, 40-50 cSt); propylene glycol block polyether was purchased from Hai'an Petrochemical Plant, Jiangsu Province; the remaining raw materials can be obtained commercially.

[0032] Example

[0033] Examples 1-3

[0034] Examples 1-3 respectively provide a protective coating for the inner surface of a water treatment device and a preparation method thereof.

[0035] The difference between the above embodiments is that the amount of each component in the protective coating on the inner surface of the water treatment equipment is different, as shown in Table 1.

[0036] The method for preparing the protective coating on the inner surface of the water treatment equipment in the above embodiment is as follows:

[0037] The modified filler is prepared by adding 100 g of palm oil polyol, 10 g of gum arabic, 0.9 g of dibutyltin dilaurate catalyst, and 25 g of nanofiller talc to 240 g of water, mixing the mixture evenly, heating the mixture to 60° C., and stirring the mixture for 60 minutes; then adding 60 g of isophorone diisocyanate, stirring the mixture for 15 minutes, and drying and curing the mixture at 80° C., and grinding the mixture to a particle size of ≤500 mesh; the weight ratio of water, vegetable oil polyol, gum arabic, catalyst, nanofiller, and aliphatic isocyanate is 250:100:10:0.9:25:60.

[0038] The preparation method of the protective agent is as follows: 7g of corn oil, 55g of castor oil polyol, and 35g of adipic acid are stirred and mixed evenly at 50°C, and then 6g of acrylic anhydride and 0.5g of tetrabutyl titanate catalyst are added, and the mixture is stirred and reacted for 75 minutes to obtain the protective agent; the weight ratio of corn oil, castor oil polyol, adipic acid, acrylic anhydride, and catalyst is 7:55:35:6:0.5.

[0039] According to Table 1, corresponding weights of E51 epoxy resin, toughening agent (the toughening agent is composed of a mixture of hydroxy silicone oil and propylene glycol block polyether in a weight ratio of 3:1; the performance parameters of propylene glycol block polyether are: model L44, molecular weight of 2200, viscosity of 440 cps at 25°C), protective agent, and dispersant (DISPERBYK-2009 solvent-based wetting and dispersing agent) are dispersed in solvent ethanol. Then, the modified filler is added while stirring at 4500 rpm, and high-speed dispersion is continued for 30 minutes. Finally, the curing agent diethylaminopropylamine is added, and the coating is obtained after high-speed stirring for 120 minutes. The coating is sprayed onto the metal surface to form a protective coating.

[0040] Table 1 Amount of modified filler in the protective coating on the inner surface of water treatment equipment in Examples 1-3 and Comparative Examples 1-2

[0041]

[0042]

[0043] Examples 4-7

[0044] Examples 4-7 respectively provide a protective coating for the inner surface of a water treatment device and a preparation method thereof.

[0045] The difference between the above embodiment and embodiment 1 is that the preparation methods of the modified filler and the protective agent are different, as shown below.

[0046] In Example 4: In the preparation method of the modified filler, the weight ratio of water, vegetable oil polyol, gum arabic, catalyst, nanofiller, and aliphatic isocyanate is 220:110:5:1.2:20:40.

[0047] In Example 5: In the preparation method of the modified filler, the nanofiller is magnesium carbonate.

[0048] In Example 6: In the preparation method of the protective agent, the weight ratio of corn oil, castor oil polyol, adipic acid, acrylic anhydride, and catalyst is 10:50:40:4:0.7.

[0049] In Example 7, in the method for preparing the protective agent, the catalyst is dioctyltin oxide.

[0050] The other process parameters in the above embodiment are the same as those in Example 1.

[0051] Examples 8-15

[0052] Examples 8-15 respectively provide a protective coating for the inner surface of a water treatment device and a preparation method thereof.

[0053] The difference between the above embodiment and embodiment 1 is that the types of toughening agents are different, as shown below.

[0054] In Example 8, the toughening agent is composed of a mixture of ethyl silicone oil and propylene glycol block polyether in a weight ratio of 3:1; the performance parameters of the propylene glycol block polyether are: molecular weight of 2200, and viscosity at 25° C. of 440 cps.

[0055] In Example 9, the toughening agent is composed of a mixture of hydroxy silicone oil and propylene glycol block polyether in a weight ratio of 3:1; the performance parameters of the propylene glycol block polyether are: model L42, molecular weight of 1630, and viscosity of 250 cps at 25°C.

[0056] In Example 10, the toughening agent is composed of a mixture of hydroxy silicone oil and propylene glycol block polyether in a weight ratio of 3:1; the performance parameters of the propylene glycol block polyether are: model L43, molecular weight of 1850, and viscosity of 310 cps at 25°C.

[0057] In Example 11, the toughening agent is composed of a mixture of hydroxy silicone oil and propylene glycol block polyether in a weight ratio of 3:1; the performance parameters of the propylene glycol block polyether are: model L63, molecular weight of 2650, and viscosity of 475 cps at 25°C.

[0058] In Example 12, the toughening agent is composed of a mixture of hydroxy silicone oil and propylene glycol block polyether in a weight ratio of 3:1; the performance parameters of the propylene glycol block polyether are: model L64, molecular weight of 2900, and viscosity of 550 cps at 25°C.

[0059] In Example 13, the toughening agent is composed of a mixture of hydroxy silicone oil and propylene glycol block polyether in a weight ratio of 1:3; the performance parameters of the propylene glycol block polyether are: model L44, molecular weight of 2200, and viscosity of 440 cps at 25°C.

[0060] In Example 14, the toughening agent is composed of a mixture of hydroxy silicone oil and propylene glycol block polyether in a weight ratio of 2:1.5; the performance parameters of the propylene glycol block polyether are: model L44, molecular weight of 2200, and viscosity of 440 cps at 25°C.

[0061] In Example 15, the toughening agent is composed of a mixture of hydroxy silicone oil and propylene glycol block polyether in a weight ratio of 4:0.5; the performance parameters of the propylene glycol block polyether are: molecular weight of 2200, and viscosity of 440 cps at 25°C.

[0062] The other process parameters in the above embodiment are the same as those in Example 1.

[0063] Comparative Example

[0064] Comparative Example 1-2

[0065] Comparative Examples 1-2 respectively provide a protective coating for the inner surface of a water treatment device and a preparation method thereof.

[0066] The difference between the comparative example and Example 1 is that the amounts of the components in the protective coating on the inner surface of the water treatment equipment are different, as shown in Table 1.

[0067] The other process parameters in the above comparative example are the same as those in Example 1.

[0068] Comparative Examples 3-6

[0069] Comparative Examples 3-6 respectively provide a protective coating for the inner surface of a water treatment device and a preparation method thereof.

[0070] The differences between the comparative example and Example 1 are specifically as follows.

[0071] In Comparative Example 3, the modified filler was replaced by an equal amount of unmodified nanofiller talc.

[0072] In Comparative Example 4: In the preparation method of the modified filler, the weight ratio of water, vegetable oil polyol, gum arabic, catalyst, nanofiller, and aliphatic isocyanate is 230:80:20:0.4:40:30.

[0073] In Comparative Example 5: no protective agent was added.

[0074] In Comparative Example 6: The preparation method of the protective agent is as follows: 55 g of castor oil polyol and 35 g of adipic acid are stirred and mixed uniformly at 50° C., and then 6 g of acrylic anhydride and 0.5 g of tetrabutyl titanate catalyst are added, and the reaction is stirred for 75 minutes to obtain the protective agent; the weight ratio of castor oil polyol, adipic acid, acrylic anhydride, and catalyst is 7:55:35:6:0.5.

[0075] The other process parameters in the above comparative example are the same as those in Example 1.

[0076] Performance testing

[0077] Impact resistance: tested in accordance with the method specified in GB / T 20624.2-2006.

[0078] Acid and alkali resistance: According to GB / T9274-1988 "Determination of resistance of paints and varnishes to liquid media", the coating is tested for resistance to 10% HCl and 10% NaOH solutions.

[0079] Salt spray resistance: Tested in accordance with GB / T1771-2007 “Paints and varnishes - Determination of resistance to neutral salt spray”.

[0080] Test results: as shown in Table 2.

[0081] Table 2 Performance test results of protective coatings in Examples and Comparative Examples

[0082]

[0083]

[0084] By comparing the performance test results of the protective coatings in the examples and comparative examples in conjunction with Table 2, it can be seen that the amounts of the raw material components in Comparative Examples 1-2 are not matched, and the performance of the protective coatings prepared is poor. In Comparative Example 3, the modified filler is replaced with an equal amount of unmodified nanofiller talc. The weight ratio of the raw materials in the preparation method of the modified filler in Comparative Example 3 is not matched. In Comparative Example 5, no protective agent is added. In Comparative Example 6, the preparation method of the protective agent does not add corn oil. As a result, the performance of the protective coating prepared is poor.

[0085] In contrast, the protective coating prepared using the technical solution of the present application is used for the inner surface of water treatment equipment. By spraying or brushing it onto the surface of the metal, a protective coating is formed. The coating has good corrosion resistance, good impact resistance, and strong acid and alkali resistance and salt spray resistance.

[0086] Furthermore, by comparing the test results of Example 1 with those of Examples 8-15, it can be seen that the type of toughening agent has a great influence on the performance of the protective coating. Through multiple experiments, the present application found that when a toughening agent is composed of a mixture of hydroxy silicone oil with a weight ratio of 2-4:0.5-1.5 and a propylene glycol block polyether with an average molecular weight of 1850-2650 and a viscosity of 310-475 cps at 25°C, the corrosion resistance of the protective coating can be further improved, thereby broadening the application of the protective coating.

[0087] Although the present invention has been described in detail above using general descriptions and specific embodiments, it will be apparent to those skilled in the art that modifications and improvements may be made based on the present invention. Therefore, such modifications and improvements, which do not depart from the spirit of the present invention, are intended to be within the scope of protection claimed herein.

Claims

1. A protective coating on the inner surface of water treatment equipment, characterized in that: Specifically, it includes the following components in parts by weight: 50-60 parts of epoxy resin, 5-10 parts of curing agent, 1-3 parts of toughening agent, 4-8 parts of modified filler, 3-7 parts of protective agent, 0.5-1.5 parts of dispersant, and 20-26 parts of solvent; The modified filler is prepared by adding vegetable oil polyol, gum arabic, a catalyst, and a nanofiller to water, mixing them evenly, heating the mixture to 50-70° C., and stirring for 30-90 minutes; then adding aliphatic isocyanate and stirring for 10-20 minutes, stirring and mixing, drying and solidifying, and grinding the mixture. The weight ratio of water, vegetable oil polyol, gum arabic, catalyst, nanofiller and aliphatic isocyanate is 220-260:90-110:5-15:0.6-1.2:20-30:40-80; The protective agent is prepared by: mixing corn oil, castor oil polyol, and adipic acid at 40-60° C., adding acrylic anhydride and a catalyst, and stirring for 60-90 minutes to obtain the protective agent; The weight ratio of corn oil, castor oil polyol, adipic acid, acrylic anhydride and catalyst is 5-10:50-60:30-40:4-8:0.2-0.7; The toughening agent is composed of a mixture of hydroxy silicone oil and propylene glycol block polyether in a weight ratio of 2-4:0.5-1.5; the propylene glycol block polyether has an average molecular weight of 1850-2650 and a viscosity of 310-475 cps at 25°C.

2. The inner surface protective coating of the water treatment equipment according to claim 1, characterized in that: Specifically, the composition includes the following components in parts by weight: 52-58 parts of epoxy resin, 6-9 parts of curing agent, 1.5-2.5 parts of toughening agent, 5-7 parts of modified filler, 4-6 parts of protective agent, 0.7-1.2 parts of dispersant and 22-24 parts of solvent.

3. The protective coating on the inner surface of the water treatment equipment according to claim 1, characterized in that: In the preparation method of the modified filler, the weight ratio of the water, vegetable oil polyol, gum arabic, catalyst, nanofiller and aliphatic isocyanate is 230-250:95-105:7-12:0.8-1.0:22-28:50-70.

4. The protective coating on the inner surface of the water treatment equipment according to claim 1, characterized in that: In the preparation method of the modified filler, the vegetable oil polyol is selected from one or more of palm oil polyol, olive oil polyol, rapeseed oil polyol, soybean oil polyol, linseed oil polyol, peanut oil polyol, and corn oil polyol; the catalyst is selected from one or more of triethylamine, triethanolamine, dibutyltin dilaurate, and stannous octoate; the nanofiller is selected from one or more of sodium lignin sulfonate, sodium silicate, magnesium carbonate, talc, and kaolin; and the aliphatic isocyanate is selected from one or more of hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, xylylene diisocyanate, and tetramethyl-m-xylylene diisocyanate.

5. The inner surface protective coating of the water treatment equipment according to claim 1, characterized in that: In the preparation method of the protective agent, the weight ratio of the corn oil, castor oil polyol, adipic acid, acrylic anhydride and catalyst is 6-9:52-58:32-37:5-7:0.3-0.

6.

6. The protective coating on the inner surface of the water treatment equipment according to claim 1, characterized in that: In the preparation method of the protective agent, the catalyst is selected from one or more of acetate, monobutyltin triisooctoate, dioctyltin oxide, tetrabutyl titanate, isopropyl titanate, and N-hydroxysuccinimide.

7. The protective coating on the inner surface of water treatment equipment according to claim 1, characterized in that: The epoxy resin is selected from one or more of E44 epoxy resin and E51 epoxy resin; the curing agent is selected from one or more of ethylenediamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine, and diethylaminopropylamine; and the solvent is selected from one or more of methanol, ethanol, or xylene.

8. The method for preparing a protective coating on the inner surface of water treatment equipment according to any one of claims 1 to 7, characterized in that: Specifically, the following steps are performed in sequence: Epoxy resin, toughening agent, protective agent and dispersant are dispersed in a solvent by weight, and then the modified filler is added under stirring at 3000-6000 rpm and high-speed dispersion is continued for 20-40 minutes; then the curing agent is added and stirred at high speed for 90-150 minutes to obtain the coating, which is sprayed or brushed onto the surface of the equipment to form a protective coating.

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