A modified alumina ceramic coating diaphragm and preparation method thereof

Abstract

This invention discloses a modified alumina ceramic coated diaphragm and its preparation method. The method involves impregnating and drying clay ceramic sheets, short-chain fatty acids, and thiourea compounds to obtain coated clay ceramic sheets. These sheets are then pulverized into clay ceramic powder. Finally, other component agents are added sequentially to obtain a modified alumina ceramic protective powder coating. After coating and drying, the modified alumina ceramic coated diaphragm is obtained. This invention improves the coating effect of the alumina ceramic protective powder by first coating the clay ceramic sheets and then pulverizing them, using a simpler and more reasonable method. The resulting coated diaphragm exhibits better toughness and heat resistance. The coating is generally neutral to slightly alkaline, making it suitable for most environments. The final coated diaphragm also possesses good anti-corrosion properties, effectively mitigating external corrosion, extending the effective lifespan of the coated diaphragm, and ensuring the service life and quality of the alumina ceramic.

Description

Technical Field

[0001] This invention relates to the field of ceramic coated membrane technology, and more specifically, to a modified alumina ceramic coated membrane and its preparation method. Background Technology

[0002] Alumina ceramics are ceramic materials with alumina as the main component, used in thick-film integrated circuits. Alumina ceramics have good electrical conductivity, mechanical strength, and high-temperature resistance.

[0003] Alumina ceramics are inherently fragile and easily damaged during use and transportation, as well as by corrosion from external liquids or turbid substances. Therefore, the most effective method is to coat the alumina ceramic with a protective coating. An alumina ceramic coating is a coating formed on the surface of the alumina ceramic to protect it.

[0004] However, the coating membrane will gradually thin out over time due to factors such as increased use and corrosion from external liquids, eventually weakening and even eliminating the original function of the coating membrane, which will have a significant impact on the protective effect of alumina ceramics. Summary of the Invention

[0005] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a method for preparing a modified alumina ceramic coated membrane, thereby solving one or more of the above-mentioned problems.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A modified alumina ceramic coated membrane, comprising the following components in parts by weight:

[0008]

[0009]

[0010] Furthermore, the adhesive is polyvinyl alcohol, the plasticizer is thermoplastic epoxy resin, the film-forming aid is alcohol ester 12, and the filler is one or more of calcium carbonate, talc, and kaolin.

[0011] Furthermore, the short-chain fatty acid is one or more of acetic acid, propionic acid, isobutyric acid, and isovaleric acid.

[0012] Furthermore, the dispersant is polyethylene glycol.

[0013] Furthermore, the thiourea compound is one or a mixture of more than one of acetone thiourea, benzaldehyde thiourea, and N,N-dimethyl-N'-[2-(2-thienyl)-2-(2-pyridyl)-1-azatenyl]-thiourea.

[0014] Based on the above preparation method, a method for preparing a modified alumina ceramic coated membrane is provided, comprising the following steps:

[0015] S1. According to the formula, place the clay ceramic sheet in a mixed solution A of anhydrous oxalic acid and liquid titanium dioxide, and immerse it in a sealed environment at 50-80℃ for 3-4 hours. After immersion, filter and dry the clay ceramic sheet, and bake it at a high temperature of 100-200℃ for 0.5-1 hours to obtain the coated clay ceramic sheet.

[0016] S2. The clay ceramic sheet obtained in step S1 is crushed into powder of 1.1-1.5μm, and the binder and plasticizer of the formula are added. In a closed environment at 150-200℃, it is further ground to 0.8-1μm to obtain alumina ceramic protective powder.

[0017] S3. Mix the short-chain fatty acids and deionized water according to the formula, add the alumina ceramic protective powder obtained in step S2, and stir for 1-2 hours at 20-30℃ to obtain mixed solution B.

[0018] S4. Add the prescribed amount of dispersant to the mixed solution B obtained in step S3, stir continuously and heat to 40-55℃ to obtain a dispersed modified alumina ceramic protective powder solution.

[0019] S5. Add the formulated amounts of thiourea compound, thickener, film-forming aid and filler to the modified alumina ceramic protective powder solution obtained in step S4, and stir until completely dissolved to obtain the modified alumina ceramic protective powder coating.

[0020] S6. After applying the modified alumina ceramic protective powder coating obtained in step S5, dry it in an oven at 50-70℃ for 5-8 minutes to obtain a modified alumina ceramic coated diaphragm.

[0021] Further, in step S1, anhydrous oxalic acid and liquid titanium dioxide are mixed in a weight ratio of 3:1.

[0022] Furthermore, during the continued grinding in step S2, stearic acid is added for lubrication, and the fatty acid content is 0.5-1 parts by weight.

[0023] Further, in step S4, after heating, a pH adjuster is added to make the pH of the prepared modified alumina ceramic protective powder solution 7-9. The pH adjuster is NaCOOCH3.

[0024] Further, in step S1, observe the coated clay ceramic sheet. If the color is bright and the surface coating is without obvious defects, proceed to step S2; if the color is dull and the surface coating is obviously defective, directly brush the additive onto the surface of the clay ceramic sheet and dry it for at least 30 minutes.

[0025] The additives consist of the following components in parts by weight:

[0026] Mixture A, 10 parts;

[0027] 15-30 parts of anhydrous ethanol;

[0028] Five parts of phenolic modified epoxy resin.

[0029] In summary, the present invention has the following beneficial effects:

[0030] By first coating clay ceramic flakes and then pulverizing them, some treatments that are difficult or impossible to perform on clay ceramic powder are achieved. This simpler and more reasonable method improves the coating effect of alumina ceramic protective powder, resulting in a coated diaphragm with better toughness and heat resistance. The coating material is generally neutral to slightly alkaline, making it suitable for most environments. The final coated diaphragm also exhibits good corrosion resistance, effectively mitigating external corrosion, extending its effective lifespan, and ensuring the service life and quality of the alumina ceramic. Detailed Implementation

[0031] In all embodiments and comparative examples of the present invention, the raw materials used are all commonly used in production in the art and can be obtained from the market without any special requirements. All equipment used in all embodiments and comparative examples is conventional equipment used in normal production.

[0032] All embodiments and comparative examples ensure that the source of raw materials and the equipment used are the same, eliminating the influence of raw material quality and equipment on product quality and test results.

[0033] Among them, N,N-dimethyl-N'-[2-(2-thienyl)-2-(2-pyridyl)-1-azatenyl]-thiourea is a chemical substance disclosed in application number CN200510030414.X, and is an existing product that can be obtained from the market in this application. The other raw materials are also available from the market and will not be described in detail.

[0034] Example 1

[0035] Take the following components in parts by weight:

[0036]

[0037] Based on the above raw materials, the following steps are followed:

[0038] S1. According to the formula, place the clay ceramic sheet in a mixed solution A of anhydrous oxalic acid and liquid titanium dioxide, and immerse it in a sealed environment at 65°C for 3 hours. Filter and dry the immersed clay ceramic sheet, and bake it at a high temperature of 150°C for 0.5 hours to obtain the coated clay ceramic sheet.

[0039] Among them, the coated clay ceramic pieces have a bright color and no obvious defects on the coated surface;

[0040] S2. The clay ceramic sheet obtained in step S1 is crushed into powder of 1.3μm, and the binder and plasticizer of the formula are added. The mixture is then ground to 1μm in a closed environment at 175℃ to obtain alumina ceramic protective powder.

[0041] S3. Mix the short-chain fatty acids and deionized water according to the formula, add the alumina ceramic protective powder obtained in step S2, and stir at 25°C for 1 hour to obtain mixed solution B.

[0042] S4. Add the prescribed amount of dispersant to the mixed solution B obtained in step S3, stir continuously and heat to 48°C to obtain a dispersed modified alumina ceramic protective powder solution.

[0043] S5. Add the formulated amounts of thiourea compound, thickener, film-forming aid and filler to the modified alumina ceramic protective powder solution obtained in step S4, and stir until completely dissolved to obtain the modified alumina ceramic protective powder coating.

[0044] S6. After applying the modified alumina ceramic protective powder coating obtained in step S5, dry it in an oven at 60°C for 5 minutes to obtain a modified alumina ceramic coated diaphragm.

[0045] Liquid titanium dioxide is a saturated solution of dissolved titanium dioxide powder.

[0046] There are no special requirements for the selection of thickeners;

[0047] In step S1, anhydrous oxalic acid and liquid titanium dioxide are mixed at a weight ratio of 3:1.

[0048] Stearic acid is added for lubrication during the grinding process in step S2, and the fatty acid is 0.5 parts by weight.

[0049] After heating in step S4, a pH adjuster is added to make the pH of the prepared modified alumina ceramic protective powder solution 7. The pH adjuster is NaCOOCH3.

[0050] The finished product is sample 1.

[0051] Example 2

[0052] Take the following components in parts by weight:

[0053]

[0054]

[0055] Based on the above raw materials, the following steps are followed:

[0056] S1. According to the formula, place the clay ceramic sheet in a mixed solution A of anhydrous oxalic acid and liquid titanium dioxide, and immerse it in a sealed environment at 65°C for 3 hours. Filter and dry the immersed clay ceramic sheet, and bake it at a high temperature of 150°C for 0.5 hours to obtain the coated clay ceramic sheet.

[0057] Among them, the coated clay ceramic pieces have a bright color and no obvious defects on the coated surface;

[0058] S2. The clay ceramic sheet obtained in step S1 is crushed into powder of 1.3μm, and the binder and plasticizer of the formula are added. The mixture is then ground to 1μm in a closed environment at 175℃ to obtain alumina ceramic protective powder.

[0059] S3. Mix the short-chain fatty acids and deionized water according to the formula, add the alumina ceramic protective powder obtained in step S2, and stir at 25°C for 1 hour to obtain mixed solution B.

[0060] S4. Add the prescribed amount of dispersant to the mixed solution B obtained in step S3, stir continuously and heat to 48°C to obtain a dispersed modified alumina ceramic protective powder solution.

[0061] S5. Add the formulated amounts of thiourea compound, thickener, film-forming aid and filler to the modified alumina ceramic protective powder solution obtained in step S4, and stir until completely dissolved to obtain the modified alumina ceramic protective powder coating.

[0062] S6. After applying the modified alumina ceramic protective powder coating obtained in step S5, dry it in an oven at 60°C for 5 minutes to obtain a modified alumina ceramic coated diaphragm.

[0063] Liquid titanium dioxide is a saturated solution of dissolved titanium dioxide powder.

[0064] There are no special requirements for the selection of thickeners;

[0065] In step S1, anhydrous oxalic acid and liquid titanium dioxide are mixed at a weight ratio of 3:1.

[0066] Stearic acid is added for lubrication during the grinding process in step S2, and the fatty acid is 0.5 parts by weight.

[0067] After heating in step S4, a pH adjuster is added to make the pH of the prepared modified alumina ceramic protective powder solution 7. The pH adjuster is NaCOOCH3.

[0068] The finished product is sample 2.

[0069] Example 3

[0070] Take the following components in parts by weight:

[0071]

[0072] Based on the above raw materials, the following steps are followed:

[0073] S1. According to the formula, place the clay ceramic sheet in a mixed solution A of anhydrous oxalic acid and liquid titanium dioxide, and immerse it in a sealed environment at 65°C for 3 hours. Filter and dry the immersed clay ceramic sheet, and bake it at a high temperature of 150°C for 0.5 hours to obtain the coated clay ceramic sheet.

[0074] Among them, the coated clay ceramic pieces have a bright color and no obvious defects on the coated surface;

[0075] S2. The clay ceramic sheet obtained in step S1 is crushed into powder of 1.3μm, and the binder and plasticizer of the formula are added. The mixture is then ground to 1μm in a closed environment at 175℃ to obtain alumina ceramic protective powder.

[0076] S3. Mix the short-chain fatty acids and deionized water according to the formula, add the alumina ceramic protective powder obtained in step S2, and stir at 25°C for 1 hour to obtain mixed solution B.

[0077] S4. Add the prescribed amount of dispersant to the mixed solution B obtained in step S3, stir continuously and heat to 48°C to obtain a dispersed modified alumina ceramic protective powder solution.

[0078] S5. Add the formulated amounts of thiourea compound, thickener, film-forming aid and filler to the modified alumina ceramic protective powder solution obtained in step S4, and stir until completely dissolved to obtain the modified alumina ceramic protective powder coating.

[0079] S6. After applying the modified alumina ceramic protective powder coating obtained in step S5, dry it in an oven at 60°C for 5 minutes to obtain a modified alumina ceramic coated diaphragm.

[0080] Liquid titanium dioxide is a saturated solution of dissolved titanium dioxide powder.

[0081] There are no special requirements for the selection of thickeners;

[0082] In step S1, anhydrous oxalic acid and liquid titanium dioxide are mixed at a weight ratio of 3:1.

[0083] Stearic acid is added for lubrication during the grinding process in step S2, and the fatty acid is 0.5 parts by weight.

[0084] After heating in step S4, a pH adjuster is added to make the pH of the prepared modified alumina ceramic protective powder solution 7. The pH adjuster is NaCOOCH3.

[0085] The finished product is sample 3.

[0086] Example 4

[0087] The difference from Example 1 is that calcium carbonate is replaced with talc or kaolin, or a mixture of the three fillers, but the amounts are exactly the same.

[0088] Three samples were obtained: 4.1, 4.2, and 4.3.

[0089] Example 5

[0090] The difference from Example 1 is that acetic acid is replaced with propionic acid, or isobutyric acid, or isovaleric acid, or a mixture of four short-chain fatty acids, but the amounts are exactly the same.

[0091] Four samples were obtained: 5.1, 5.2, 5.3, and 5.4.

[0092] Example 6

[0093] The difference from Example 1 is that acetone thiourea is replaced with benzaldehyde thiourea, or N,N-dimethyl-N'-[2-(2-thienyl)-2-(2-pyridyl)-1-azaenyl]-thiourea, or a mixture of the three thiourea compounds, but in exactly the same amounts.

[0094] Three samples were obtained: 6.1, 6.2, and 6.3.

[0095] Example 7

[0096] The difference from Example 1 is that the clay ceramic sheet is first crushed into powder by the crushing method in step S2, and then the obtained powder is impregnated and dried by vacuum filtration according to the method in step S1, while other conditions remain unchanged, to obtain sample 7.

[0097] Example 8

[0098] The difference from Example 1 is that clay ceramic sheets with dull surface color and obvious defects after coating in step S1 are selected, and the additive is directly brushed onto the surface of the clay ceramic sheets and dried for at least 30 minutes.

[0099] The additives consist of the following components in parts by weight:

[0100] Mixture A, 10 parts;

[0101] 15-30 parts of anhydrous ethanol;

[0102] Five parts of phenolic modified epoxy resin.

[0103] There are no requirements for the amount of anhydrous ethanol used; it can be more or less without affecting the quality and properties of the additive.

[0104] The preparation process of the additives involves adding each component into a homogenizer and dispersing it evenly for at least 1 hour, then removing it, sealing it, and storing it for later use.

[0105] There are no special requirements for the coating method.

[0106] Sample 8 was obtained.

[0107] Comparative Example 1

[0108] Alumina ceramic without a coating was selected to obtain control part 1.

[0109] Alumina ceramic sheets (samples 1, 2, 3, 4.1, 4.2, 4.3, 5.1, 5.2, 5.3, 5.4, 6.1, 6.2, 6.3, 7, and 8) and control sample 1 were subjected to a life test. Specifically, the sheets were charged for 150 minutes at a constant current and constant voltage of 1C at room temperature (25°C), and then discharged to a cutoff voltage of 2.75V at a constant current of 1C, constituting one cycle. The test ended when any discharge time was less than 36 minutes. The number of cycles was 300, and the thickness of the coating membrane was observed after the experiment. This test assesses the durability of the coating membrane in a conductive environment.

[0110] Samples 1, 2, 3, 4.1, 4.2, 4.3, 5.1, 5.2, 5.3, 5.4, 6.1, 6.2, 6.3, 7, 8, and Comparison 1 were used. Under the same conditions, the coated diaphragm was steadily cut along a straight line to the substrate with a utility knife at an angle of 30°-45°, with a cut length of 40mm. Transparent tape was applied and smoothed along the cut lines. The tape was then peeled off the coated diaphragm surface at a 180° angle, and the state of the coating after peeling was observed. This was used to observe the adhesion of the coated diaphragm. According to the standard, no peeling was grade A, obvious peeling was grade B, obvious gaps were grade C, and large areas of peeling were grade D.

[0111] The coating conditions of samples 1, 2, 3, 4.1, 4.2, 4.3, 5.1, 5.2, 5.3, 5.4, 6.1, 6.2, 6.3, 7, 8, and control sample 1 were observed under environmental conditions of 5% H₂SO₄ at 25°C for 700 h and 3% NaOH at 25°C for 800 h, respectively. This was used to test the corrosion resistance.

[0112] The situation is summarized in the table below:

[0113]

[0114] The data in the table shows that comparing samples 1-3 individually reveals that a higher amount of raw material weakens the adhesion of the coated membrane, but improves its durability and corrosion resistance. Comparing samples 4.1-4.3 individually shows that using a mixture of three fillers does not significantly affect the durability of the coated membrane, but improves both adhesion and corrosion resistance. Comparing samples 5.1-5.4 individually reveals that a mixture of four short-chain fatty acids actually negatively impacts the corrosion resistance of the coated membrane. Comparing samples 6.1-6... .3 A separate comparison revealed that when N,N-dimethyl-N'-[2-(2-thienyl)-2-(2-pyridyl)-1-azaenyl]-thiourea was used, the coating membrane exhibited advantages in both adhesion and corrosion resistance. A separate comparison between Sample 1 and Sample 7 showed that the method of coating first and then crushing resulted in significant advantages in the durability, adhesion, and corrosion resistance of the coated membrane. A separate comparison between Sample 1 and Sample 8 revealed that the additive coating was only a remedial measure, and the actual quality and performance of the coated membrane were significantly affected.

[0115] Based on the summary of all sample data, the overall corrosion resistance of the coated diaphragm of this application is good. However, the absence of the alumina ceramic sheet coating surface in step S1 should be avoided as much as possible. The filler is preferably a mixture of multiple raw materials. The preferred aminothiourea compound is N,N-dimethyl-N'-[2-(2-thienyl)-2-(2-pyridyl)-1-azaenyl]-thiourea. The method of coating the alumina ceramic sheet surface first and then crushing it can effectively improve the toughness and heat resistance of the coated diaphragm, thereby counteracting the impact on the coated diaphragm during use and improving the durability of the coated diaphragm. Producing with an appropriate amount of raw materials helps to improve the adhesion of the coated diaphragm.

[0116] In summary, the coated diaphragm of this application has better corrosion resistance. The special process of the coated diaphragm gives it better heat resistance and toughness, which improves the durability of the coated diaphragm and its adhesion, thus helping to improve the service life and quality of alumina ceramics.

[0117] It should be noted that this specific embodiment is merely an explanation of the present invention and is not intended to limit the present invention. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but as long as they are within the scope of the claims of the present invention, they are protected by patent law.

Claims

1. A modified alumina ceramic coated diaphragm, characterized in that: It consists of the following components in parts by weight: 20-30 pieces of clay ceramic shards; 8-12 parts of anhydrous oxalic acid; Liquid titanium dioxide, 2.7-4.1 parts; 2.3-5.6 parts adhesive; Plasticizer 1.7-2.4 parts; Short-chain fatty acids: 3.2-4.9 parts; 44-50 parts deionized water; 5-9 parts dispersant; Thiourea compounds, 11.5-16.7 parts; Thickener 6-7 parts; 15-35 parts of filler; Film-forming aid 0.8-2 parts; S1. According to the formula, the clay ceramic sheet is placed in a mixed solution A of anhydrous oxalic acid and liquid titanium dioxide. After being impregnated in a closed environment, it is filtered, dried and baked at high temperature to obtain a coated clay ceramic sheet. S2. Crush the clay ceramic sheet obtained in step S1 into powder, add the formula amount of binder and plasticizer, and continue grinding in a sealed environment to obtain alumina ceramic protective powder. S3. Mix the short-chain fatty acids and deionized water according to the formula, add the alumina ceramic protective powder obtained in step S2, and stir to obtain mixed solution B. S4. Add the prescribed amount of dispersant to the mixed solution B obtained in step S3, stir continuously and heat up to obtain a dispersed modified alumina ceramic protective powder solution. S5. Add the formulated amounts of thiourea compound, thickener, film-forming aid and filler to the modified alumina ceramic protective powder solution obtained in step S4, and stir until completely dissolved to obtain the modified alumina ceramic protective powder coating. S6. The modified alumina ceramic protective powder coating obtained in step S5 is coated and then dried in an oven to obtain a modified alumina ceramic coated diaphragm.

2. The modified alumina ceramic coated diaphragm according to claim 1, characterized in that: The adhesive is polyvinyl alcohol, the plasticizer is thermoplastic epoxy resin, the film-forming aid is alcohol ester 12, and the filler is one or more of calcium carbonate, talc, and kaolin.

3. The modified alumina ceramic coated diaphragm according to claim 1, characterized in that: The short-chain fatty acid is one or a mixture of acetic acid, propionic acid, isobutyric acid, and isovaleric acid.

4. The modified alumina ceramic coated diaphragm according to claim 1, characterized in that: The dispersant is polyethylene glycol.

5. The modified alumina ceramic coated diaphragm according to claim 1, characterized in that: The thiourea compounds are one or a mixture of more of the following: acetone thiourea, benzaldehyde thiourea, and N,N-dimethyl-N'-[2-(2-thienyl)-2-(2-pyridyl)-1-azatenyl]-thiourea.

6. A method for preparing a modified alumina ceramic coated diaphragm, characterized in that: The modified alumina ceramic coated membrane according to any one of claims 1-5 is prepared according to the following steps: S1. According to the formula, place the clay ceramic sheet in a mixed solution A of anhydrous oxalic acid and liquid titanium dioxide, and immerse it in a sealed environment at 50-80℃ for 3-4 hours. After immersion, filter and dry the clay ceramic sheet, and bake it at a high temperature of 100-200℃ for 0.5-1 hours to obtain the coated clay ceramic sheet. S2. The clay ceramic sheet obtained in step S1 is crushed into powder of 1.1-1.5μm, and the binder and plasticizer of the formula are added. In a closed environment at 150-200℃, it is further ground to 0.8-1μm to obtain alumina ceramic protective powder. S3. Mix the short-chain fatty acids and deionized water according to the formula, add the alumina ceramic protective powder obtained in step S2, and stir for 1-2 hours at 20-30℃ to obtain mixed solution B. S4. Add the prescribed amount of dispersant to the mixed solution B obtained in step S3, continue stirring and heat to 40-55℃ to obtain a dispersed modified alumina ceramic protective powder solution. S5. Add the formulated amounts of thiourea compound, thickener, film-forming aid and filler to the modified alumina ceramic protective powder solution obtained in step S4, and stir until completely dissolved to obtain the modified alumina ceramic protective powder coating. S6. After applying the modified alumina ceramic protective powder coating obtained in step S5, dry it in an oven at 50-70℃ for 5-8 minutes to obtain a modified alumina ceramic coated diaphragm.

7. The method for preparing the modified alumina ceramic coated diaphragm according to claim 6, characterized in that: In step S1, anhydrous oxalic acid and liquid titanium dioxide are mixed at a weight ratio of 3:

1.

8. The method for preparing the modified alumina ceramic coated diaphragm according to claim 6, characterized in that: Stearic acid is added for lubrication during the continued grinding in step S2, and the fatty acid is 0.5-1 parts by weight.

9. The method for preparing the modified alumina ceramic coated diaphragm according to claim 6, characterized in that: In step S4, after heating, a pH adjuster is added to make the pH of the prepared modified alumina ceramic protective powder solution 7-9. The pH adjuster is NaCOOCH3.

10. The method for preparing the modified alumina ceramic coated diaphragm according to claim 6, characterized in that: In step S1, observe the coated clay ceramic sheet. If the color is bright and the surface coating is intact, proceed to step S2. If the color is dull and the surface coating is intact, apply the additive directly to the surface of the clay ceramic sheet and let it dry for at least 30 minutes. The additives consist of the following components in parts by weight: Mixed solution A, 10 parts; 15-30 parts of anhydrous ethanol; Five parts of phenolic modified epoxy resin.

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