Protective coating for inner surface of water treatment equipment and preparation method of protective coating

Abstract

The invention relates to the technical field of coatings, and particularly discloses a protective coating for the inner surface of water treatment equipment and a preparation method of the protective coating. The invention discloses a protective coating for the inner surface of water treatment equipment. The protective coating is specifically prepared from components in parts by weight as follows: 50-60 parts of epoxy resin, 5-10 parts of a curing agent, 1-3 parts of a toughening agent, 4-8 parts of modified filler, 3-7 parts of a protective agent, 0.5-1.5 parts of a dispersing agent and 20-26 parts of a solvent, the modified filler is prepared from vegetable oil polyol, Arabic gum, a catalyst, a nano filler and aliphatic isocyanate; the protective agent is prepared by stirring corn oil, castor oil polyol, adipic acid, acrylic anhydride and a catalyst. The inner surface protective coating of the water treatment equipment, which is prepared by utilizing the technical scheme of the invention, has good impact resistance and relatively strong acid and alkali resistance and salt fog resistance.

Description

Technical Field

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

[0002] At present, with the increasing requirements for water quality in industrial production, water treatment has become an essential part. However, it has been found in actual operation that many water treatment facilities will show serious inner wall corrosion after a period of operation. There are mainly two common methods in the current market: one is to regularly replace damaged components; the other is to spray or brush ordinary paint to extend the service life of the equipment. The former is costly; the latter is relatively economical and practical, but due to the poor weather resistance of the paint itself, it cannot fundamentally solve the problem. This not only increases the maintenance cost but also affects the normal operation of the system.

[0003] Therefore, developing a new type of high-efficiency anti-corrosion coating is of great significance for improving water treatment efficiency. Summary of the Invention

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

[0005] The present application provides an inner surface protective coating for a water treatment device, which specifically comprises 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 preparation method of the modified filler is as follows: add vegetable oil polyol, arabic gum, catalyst, and nano filler into water, mix evenly, heat the temperature to 50 - 70 °C, and stir for 30 - 90 min; then add aliphatic isocyanate and stir for 10 - 20 min, stir and mix evenly, dry and cure, and grind to obtain; Among them, the weight ratio of the water, vegetable oil polyol, arabic gum, catalyst, nano filler, and aliphatic isocyanate is 220 - 260:90 - 110:5 - 15:0.6 - 1.2:20 - 30:40 - 80; The preparation method of the protective agent is as follows: take corn oil, castor oil polyol, and adipic acid, stir and mix evenly at 40 - 60 °C, then add acrylic anhydride and catalyst, and stir and react for 60 - 90 min to obtain the protective agent; 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.

[0006] In the technical solution of this application, epoxy resin, as the main film-forming substance, has good corrosion resistance and adhesion, can form a dense protective film, effectively isolate water, oxygen and other corrosive substances, thereby protecting the inner surface of the water treatment equipment. The curing agent reacts chemically with the epoxy resin to cure it into a hard coating, improving the wear resistance and durability of the coating. The addition of a toughening agent can improve the flexibility and impact resistance of the coating, preventing the coating from cracking or peeling when subjected to external forces. The modified filler can enhance the comprehensive performance of the coating, improve hardness, wear resistance, scratch resistance, etc., and at the same time can reduce costs. The protective agent can further improve the corrosion resistance of the coating and extend the service life of the equipment. The function of the dispersant is to uniformly disperse each component in the paint, prevent the paint from precipitating or stratifying during storage and use, and ensure the uniformity and stability of the coating. The solvent mainly plays the role of dissolving and diluting the paint components, facilitating the construction and coating of the paint. These components jointly ensure the excellent performance and long-term protection effect of the coating in the preparation of the protective coating for the inner surface of the water treatment equipment.

[0007] This application uses vegetable oil polyol, gum arabic, catalyst, nano-filler, aliphatic isocyanate to prepare the modified filler. Among them, the vegetable oil polyol, as the matrix material, provides good flexibility, water resistance and impact resistance, thereby protecting the inner surface of the water treatment equipment from corrosion; gum arabic plays a thickening and stabilizing role, helps to improve the film-forming property of the filler, and also helps to improve the adhesion and durability of the coating, thereby enhancing the corrosion resistance; the nano-filler can enhance the mechanical properties and corrosion resistance of the coating, while improving the hardness, wear resistance and scratch resistance of the coating; the aliphatic isocyanate acts as a cross-linking agent in the modified filler, reacts with the vegetable oil polyol to form a network structure, and improves the weather resistance and chemical resistance of the coating.

[0008] This application uses corn oil, castor oil polyol, adipic acid, acrylic anhydride, catalyst to prepare the protective agent. Introducing corn oil and castor oil polyol as the main raw materials can further enhance the flexibility and water resistance of the coating, thereby improving the corrosion resistance; through the action of the catalyst, adipic acid reacts chemically with raw materials such as acrylic anhydride to form a cross-linked structure; this cross-linked structure cooperates with the introduced corn oil and castor oil polyol, can significantly improve the hardness and impact resistance of the coating, and at the same time improve the corrosion resistance of the coating.

[0009] Preferably, the protective coating for 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.

[0010] Preferably, in the preparation method of the modified filler, the weight ratio of water, vegetable oil polyol, arabic gum, catalyst, nano filler, and aliphatic isocyanate is 230-250:95-105:7-12:0.8-1.0:22-28:50-70.

[0011] 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; the nano filler is selected from one or several of sodium lignosulfonate, sodium silicate, magnesium carbonate, talcum powder, and kaolin.

[0012] Preferably, in the preparation method of the protective agent, the weight ratio of corn oil, castor oil polyol, adipic acid, acrylic anhydride, and catalyst is 6-9:52-58:32-37:5-7:0.3-0.6.

[0013] Preferably, in the preparation method of the protective agent, the catalyst is selected from one or more of acetate, monobutyltin triisooctanoate, dioctyltin oxide, tetrabutyl titanate, isopropyl titanate, and N-hydroxysuccinimide.

[0014] 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; the solvent is selected from one or more of methanol, ethanol, or xylene.

[0015] Preferably, the toughening agent is composed of a mixture of hydroxy silicone oil and propylene glycol block polyether with a weight ratio of 2-4:0.5-1.5.

[0016] In a specific embodiment, the weight ratio of the hydroxy silicone oil and 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.

[0017] Preferably, the average molecular weight of the propylene glycol block polyether is 1850-2650, and the viscosity at 25°C is 310-475 cps.

[0018] In a specific embodiment, the performance parameters of the propylene glycol block polyether are: model L43, molecular weight of 1850, and viscosity at 25°C of 310 cps.

[0019] In a specific embodiment, the performance parameters of the propylene glycol block polyether are as follows: model L44, molecular weight of 2200, and viscosity at 25 °C of 440 cps.

[0020] In a specific embodiment, the performance parameters of the propylene glycol block polyether are as follows: model L63, molecular weight of 2650, and viscosity at 25 °C of 475 cps.

[0021] Through experimental analysis, it can be seen that the type of toughening agent has a great influence on the performance of the protective coating. Through multiple experiments in this application, it is found that when the toughening agent is composed of hydroxyl silicone oil with a weight ratio of 2-4:0.5-1.5 and propylene glycol block polyether with an average molecular weight of 1850-2650 and a viscosity at 25 °C of 310-475 cps, the corrosion resistance of the protective coating can be further improved.

[0022] In a second aspect, the present application provides a method for preparing the inner surface protective coating of the above water treatment equipment, which is characterized in that it specifically includes the following steps in sequence: By weight, disperse epoxy resin, toughening agent, protective agent, and dispersant in a solvent, then add modified filler under stirring at 3000-6000 rpm, and continue high-speed dispersion for 20-40 min; then add a curing agent, and after high-speed stirring for 90-150 min, obtain a coating, and form a protective coating by spraying or brushing on the surface of the equipment.

[0023] In summary, the technical solution of the present application has the following effects: 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, and then a protective coating is prepared, jointly ensuring the excellent performance and long-term protection effect of the coating, making the coating have good impact resistance, and strong acid and alkali resistance and salt spray resistance. Specific Embodiments

[0024] The following further describes the present application in detail in combination with examples, comparative examples, and performance detection tests. These examples should not be construed as limiting the scope claimed by the present application.

[0025] 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 (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 ~ 25cSt) was purchased from Aladdin, ethyl silicone oil (CAS No.: 63148-61-8, 40-50cSt); propylene glycol block polyether was purchased from Hai'an Petrochemical Plant, Jiangsu Province; the remaining raw materials can be obtained through commercial purchase. Example

[0026] Examples 1-3 Examples 1-3 respectively provide a protective coating for the inner surface of a water treatment device and a preparation method thereof.

[0027] The difference between the above embodiments is that the dosage of each component in the protective coating on the inner surface of the water treatment equipment is different, as shown in Table 1.

[0028] The method for preparing the protective coating on the inner surface of the water treatment equipment in the above embodiment is as follows: The preparation method of the modified filler is as follows: add 100g of palm oil polyol, 10g of gum arabic, 0.9g of dibutyltin dilaurate catalyst, and 25g of nano filler talc into 240g of water, mix evenly, heat to 60°C, and stir for 60min; then add 60g of isophorone diisocyanate and stir for 15min, stir and mix evenly, dry and solidify at 80°C, and grind to a particle size of ≤500 mesh; the weight ratio of water, vegetable oil polyol, gum arabic, catalyst, nano filler, and aliphatic isocyanate is 250:100:10:0.9:25:60.

[0029] The preparation method of the protective agent is as follows: take 7g corn oil, 55g castor oil polyol, and 35g adipic acid and stir and mix them evenly at 50°C, then add 6g acrylic anhydride and 0.5g tetrabutyl titanate catalyst, stir and react 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.

[0030] According to Table 1, E51 epoxy resin, toughening agent (the toughening agent is composed of hydroxy silicone oil and propylene glycol block polyether mixed in a weight ratio of 3:1; the performance parameters of propylene glycol block polyether are: model L44, molecular weight 2200, viscosity at 25°C 440 cps), protective agent, and dispersant (BYK DISPERBYK-2009 solvent-based wetting dispersant) with corresponding weights are dispersed in solvent ethanol, and then modified filler is added under stirring at 4500 rpm, and high-speed dispersion is continued for 30 min; then curing agent diethylaminopropylamine is added, and after high-speed stirring for 120 min, a coating is obtained, which is sprayed onto the metal surface to form a protective coating.

[0031] Table 1 Dosage of modified filler in the protective coating on the inner surface of the water treatment equipment in Examples 1-3 and Comparative Examples 1-2 Examples 4-7 Examples 4-7 respectively provide a protective coating for the inner surface of a water treatment equipment and a preparation method thereof.

[0032] The differences between the above examples and Example 1 are as follows: the preparation methods of the modified filler and the protective agent are different, as shown below.

[0033] In Example 4: In the preparation method of the modified filler, the weight ratio of water, vegetable oil polyol, gum arabic, catalyst, nano filler, and aliphatic isocyanate is 220:110:5:1.2:20:40.

[0034] In Example 5: In the preparation method of the modified filler, the nano filler is magnesium carbonate.

[0035] 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.

[0036] In Example 7: In the preparation method of the protective agent, the catalyst is dioctyltin oxide.

[0037] The other process parameters in the above examples are the same as those in Example 1.

[0038] Examples 8-15 Examples 8-15 respectively provide a protective coating for the inner surface of a water treatment equipment and a preparation method thereof.

[0039] The differences between the above examples and Example 1 are as follows: the types of toughening agents are different, as shown below.

[0040] In Example 8: The toughening agent is composed of ethyl silicone oil and propylene glycol block polyether mixed in a weight ratio of 3:1; the performance parameters of the propylene glycol block polyether are: molecular weight of 2200, viscosity at 25°C of 440 cps.

[0041] In Example 9: The toughening agent is composed of hydroxy silicone oil and propylene glycol block polyether mixed in a weight ratio of 3:1; the performance parameters of the propylene glycol block polyether are: model L42, molecular weight of 1630, viscosity at 25°C of 250 cps.

[0042] In Example 10: The toughening agent is composed of hydroxy silicone oil and propylene glycol block polyether mixed in a weight ratio of 3:1; the performance parameters of the propylene glycol block polyether are: model L43, molecular weight of 1850, viscosity at 25°C of 310 cps.

[0043] In Example 11: The toughening agent is composed of hydroxy silicone oil and propylene glycol block polyether mixed in a weight ratio of 3:1; the performance parameters of the propylene glycol block polyether are: model L63, molecular weight of 2650, viscosity at 25°C of 475 cps.

[0044] In Example 12: The toughening agent is composed of hydroxy silicone oil and propylene glycol block polyether mixed in a weight ratio of 3:1; the performance parameters of the propylene glycol block polyether are: model L64, molecular weight of 2900, viscosity at 25°C of 550 cps.

[0045] In Example 13: The toughening agent is composed of hydroxy silicone oil and propylene glycol block polyether mixed in a weight ratio of 1:3; the performance parameters of the propylene glycol block polyether are: model L44, molecular weight of 2200, viscosity at 25°C of 440 cps.

[0046] In Example 14: The toughening agent is composed of hydroxy silicone oil and propylene glycol block polyether mixed in a weight ratio of 2:1.5; the performance parameters of the propylene glycol block polyether are: model L44, molecular weight of 2200, viscosity at 25°C of 440 cps.

[0047] In Example 15: The toughening agent is composed of hydroxy silicone oil and propylene glycol block polyether mixed in a weight ratio of 4:0.5; the performance parameters of the propylene glycol block polyether are: molecular weight of 2200, viscosity at 25°C of 440 cps.

[0048] In the above examples, other process parameters are the same as those in Example 1.

[0049] Comparative Example Comparative Examples 1-2 Comparative Examples 1-2 respectively provide an inner surface protective coating for a water treatment device and a preparation method thereof.

[0050] The differences between the above comparative examples and Example 1 are as follows: the dosages of the components in the inner surface protective coating of the water treatment equipment are different, as shown in Table 1 specifically.

[0051] Other process parameters in the above comparative examples are the same as those in Example 1.

[0052] Comparative Examples 3-6 Comparative Examples 3-6 respectively provide an inner surface protective coating for a water treatment equipment and a preparation method thereof.

[0053] The differences between the above comparative examples and Example 1 are specifically as follows.

[0054] In Comparative Example 3: unmodified nano-filler talcum powder is used to replace the modified filler in equal amounts.

[0055] In Comparative Example 4: in the preparation method of the modified filler, the weight ratio of water, vegetable oil polyol, gum arabic, catalyst, nano-filler, and aliphatic isocyanate is 230:80:20:0.4:40:30.

[0056] In Comparative Example 5: the protective agent is not added.

[0057] In Comparative Example 6: the preparation method of the protective agent is as follows: take 55 g of castor oil polyol and 35 g of adipic acid, stir and mix evenly at 50 °C, then add 6 g of acrylic anhydride and 0.5 g of tetrabutyl titanate catalyst, and stir and react for 75 min 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.

[0058] Other process parameters in the above comparative examples are the same as those in Example 1.

[0059] Performance detection test Impact resistance: It is detected according to the specified method in GB / T 20624.2-2006.

[0060] Acid and alkali resistance: The coating is tested for resistance to 10% HCl and 10% NaOH solutions according to GB / T9274-1988 "Determination of Resistance of Paints and Varnishes to Liquid Media".

[0061] Salt spray resistance: It is detected according to GB / T1771-2007 "Determination of Resistance of Paints and Varnishes to Neutral Salt Spray".

[0062] Detection results: As shown in Table 2.

[0063] Table 2 Performance detection results of the protective coatings in the examples and comparative examples Combined with Table 2, by comparing the performance test results of the protective coatings in the examples and comparative examples, it can be seen that the dosages of the raw material components in Comparative Examples 1-2 do not match, and the performance of the prepared protective coatings is poor; in Comparative Example 3, unmodified nano-filler talc powder is used to replace the modified filler in equal amounts, and the weight ratios of the raw materials in the preparation method of the modified filler in Comparative Example 3 do not match; in Comparative Example 5, the protective agent is not added; in Comparative Example 6, corn oil is not added in the preparation method of the protective agent, and the performance of the prepared protective coatings is poor.

[0064] In contrast, by using the technical solution of the present application, the prepared protective coating is used for the inner surface of the water treatment equipment, and is sprayed or brushed onto the surface of the metal to form a protective coating, which has good corrosion resistance, good impact resistance, and strong acid and alkali resistance and salt spray resistance.

[0065] Furthermore, by comparing the test results of Example 1 and 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 the toughening agent is composed of a mixture of hydroxyl silicone oil with a weight ratio of 2-4:0.5-1.5 and 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.

[0066] Although the present invention has been described in detail with general descriptions and specific embodiments above, on the basis of the present invention, some modifications or improvements can be made, which are obvious to those skilled in the art. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of the present invention claimed.

Claims

1. A protective coating for the inner surface of a water treatment device, 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 preparation method of the modified filler is as follows: add vegetable oil polyol, gum arabic, catalyst, and nano filler into water, mix evenly, heat to 50-70° C., and stir for 30-90 minutes; then add aliphatic isocyanate and stir for 10-20 minutes, stir and mix evenly, dry and solidify, and grind to obtain the modified filler; 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 preparation method of the protective agent is: taking corn oil, castor oil polyol, and adipic acid and stirring and mixing them evenly at 40-60° C., then adding acrylic anhydride and a catalyst, stirring and reacting for 60-90 minutes, and obtaining the protective agent; 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.

2. The protective coating on the inner surface of water treatment equipment according to claim 1, characterized in that: Specifically, the composition 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.

3. The protective coating on the inner surface of water treatment equipment according to claim 1, characterized in that: In the preparation method of the modified filler, the weight ratio of the water, the vegetable oil polyol, the gum arabic, the catalyst, the nanofiller and the 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 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; the aliphatic isocyanate is selected from one or more of hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, xylene diisocyanate, and tetramethyl-m-xylene diisocyanate.

5. The protective coating for the inner surface of 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 for the inner surface of 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 inner surface protective coating 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 protective coating for the inner surface of water treatment equipment according to claim 1, characterized in that: The toughening agent is composed of 2-4 weight ratio: It is composed of a mixture of 0.5-1.5 hydroxy silicone oil and propylene glycol block polyether.

9. The protective coating for the inner surface of water treatment equipment according to claim 8, characterized in that: The average molecular weight of the propylene glycol block polyether is 1850-2650, and the viscosity at 25° C. is 310-475 cps.

10. The method for preparing the protective coating on the inner surface of water treatment equipment according to any one of claims 1 to 9, characterized in that: Specifically, the following steps are performed in sequence: According to weight, epoxy resin, toughening agent, protective agent and dispersant are dispersed in a solvent, and then the modified filler is added under stirring at 3000-6000rpm, and high-speed dispersion is continued for 20-40min; then the curing agent is added, and the coating is obtained after high-speed stirring for 90-150min, which is sprayed or brushed on the surface of the equipment to form a protective coating.

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