Silicon aluminum oxide coating material and preparation method thereof

Abstract

The application belongs to the field of coating material preparation, and discloses a silicon-aluminum oxide coating material and a preparation method thereof. The preparation method of the silicon-aluminum oxide coating material comprises the following steps: step 1: ball-milling and mixing alumina powder and silica powder to obtain mixed powder A; step 2: taking out 90-99% of the mixed powder A for normal-pressure sintering to obtain a silicon-aluminum oxide structural material; step 3: sequentially crushing, ball-milling and screening the silicon-aluminum oxide structural material to obtain a silicon-aluminum oxide structural powder; step 4: mixing the remaining 1-10% of the mixed powder A with the silicon-aluminum oxide structural powder to obtain mixed powder B; and step 5: forming and tabletting the mixed powder B to obtain a green body for normal-pressure sintering. The sintering temperature in step 5 is not higher than that in step 2. The sintering temperature in the secondary sintering is not higher than that in the primary sintering, the size of the silicon-aluminum oxide coating material is controlled, and the product quality of the silicon-aluminum oxide coating material is effectively improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of coating material preparation, in particular to a silicon aluminum oxide coating material and a preparation method thereof. BACKGROUND

[0002] With the development of vacuum coating technology, many fields begin to coat devices, and good thin films make devices have higher performance.

[0003] Among them, there are plastic lens fields, such as plastic lenses, mobile phone shells, lenses, etc. The surface of the plastic lens needs to be coated like ordinary optical lenses. After coating, it needs to be tested for waterproofness, water boiling, salt spray, and cold and hot impact to test the firmness. The silicon dioxide and aluminum oxide mixture coating material has good coating performance on the plastic substrate.

[0004] Chinese patent application 201811034057.8 discloses a preparation method of an optical vacuum coating mixed material, comprising the following steps: opening the vacuum package respectively, and weighing according to the required proportion; first slowly introducing the weighed silicon dioxide into the stirring tank of the stirrer, then slowly introducing the weighed aluminum oxide into the stirring tank of the stirrer, turning on the power of the stirrer, starting the stirrer, and stirring for 48-72h to make the material fully and uniformly stirred; after stopping stirring, opening the discharge port of the stirring tank, and using a containing container to receive the stirred mixture; granulating the stirred mixture in a granulator; loading the granulated particles into a vacuum sintering furnace for sintering, achieving a vacuum of 1*10 -3 Pa, and reaching a temperature of 1300℃. The sintering is divided into stages to ensure the vacuum degree, temperature, and sintering time of 24 hours. After cooling to room temperature, the material is taken out in a vacuum, weighed, and vacuum packaged.

[0005] The above patent application discloses a preparation method of a silicon aluminum oxide coating material, which adopts the technical means of mixing silicon dioxide and aluminum oxide, granulating, and sintering to improve the stain resistance and wound resistance of the silicon aluminum oxide coating material, so that it is resistant to acid, alkali, corrosion, and high temperature.

[0006] The above patent application adopts the conventional technical means of mixing, granulating, and sintering, but the above patent does not perform tabletting before sintering, and the applicability of the prepared silicon aluminum oxide coating material needs to be investigated.

[0007] After many experiments and customer feedback, it is found that the silicon aluminum oxide coating material prepared by the conventional preparation method has the following defects:

[0008] (1) The size of the finally produced silicon aluminum oxide coating material changes greatly, with a large error, and the error degree can be as high as 10-20%, which needs to be processed twice to ensure the size is qualified;

[0009] (2) The yield of the silicon aluminum oxide coating material is low, and the cracking frequency of the silicon aluminum oxide coating material is high;

[0010] (3) The produced silicon aluminum oxide coating material has a powder dropping problem, which causes the downstream customers to have more sputtering times in the evaporation coating process, thereby increasing the production cost.

[0011] Therefore, in order to improve the competitiveness of the product, a silicon aluminum oxide coating material with higher yield and better quality needs to be developed to meet the needs of downstream customers. SUMMARY

[0012] One of the purposes of the present application is to provide a preparation method of a silicon aluminum oxide coating material, so as to solve the problems of the preparation method of the silicon aluminum oxide coating material in the prior art, such as low yield and difficult to meet the development of the current vacuum coating technology, and to prepare a silicon aluminum oxide coating material with high yield and good quality, thereby improving the competitiveness of the product.

[0013] Another purpose of the present application is to provide a silicon aluminum oxide coating material prepared by the above preparation method, which has the advantages of small size difference, high yield and no powder dropping.

[0014] To achieve the above purpose, the present application provides a preparation method of a silicon aluminum oxide coating material, comprising the following steps:

[0015] Step 1: Ball milling the aluminum oxide powder and the silicon dioxide powder to obtain a mixed powder A with a particle size D90<10 μm, wherein the mass percentage of the aluminum oxide in the mixed powder A is 10-30%, and the mass percentage of the silicon dioxide is 70-90%;

[0016] Step 2: Taking out 90-99% of the mass of the mixed powder A obtained in step 1 to perform normal pressure sintering, thereby obtaining a silicon aluminum oxide structure material;

[0017] Step 3: The silicon aluminum oxide structure material obtained in step 2 is sequentially subjected to crushing, ball milling and sieving, thereby obtaining a silicon aluminum oxide structure powder with a particle size D90<100 μm;

[0018] Step 4: Mixing the remaining 1-10% of the mass of the mixed powder A with the silicon aluminum oxide structure powder obtained in step 3 to obtain a mixed powder B;

[0019] Step 5: Forming and tabletting the mixed powder B to obtain a green body, and sintering the green body under normal pressure to obtain a silicon aluminum oxide coating material;

[0020] The sintering temperature of the normal pressure sintering in step 5 is not higher than the sintering temperature of the normal pressure sintering in step 2.

[0021] Preferably, the sintering temperature of the step 2 atmospheric sintering is 1200-1400℃, the heating rate is 0.5-5℃ / min, and the holding time is 3-6h.

[0022] Preferably, the sintering temperature of the step 5 atmospheric sintering is 1100-1400℃, the heating rate is 0.5-5℃ / min, and the holding time is 3-6h.

[0023] Preferably, the size of the step 5 green body is Φ20mm*(10±0.1)mm.

[0024] The application also provides a silicon-aluminum oxide coating material prepared by the above-mentioned method.

[0025] Preferably, the size of the silicon-aluminum oxide coating material is Φ(20±0.1)mm*(10±0.1)mm.

[0026] Advantages

[0027] Compared with the prior art, the application has at least the following advantages:

[0028] (1) The application provides a preparation method of a silicon-aluminum oxide coating material, which effectively reduces the size influence caused by the crystal change of the mixed powder in the atmospheric sintering process by the technical means of dividing the mixed aluminum oxide and silicon dioxide powder obtained by mixing into two parts, sintering most of the mixed powder to obtain a silicon-aluminum oxide structure material, and then crushing, ball milling and re-mixing with the other part of the mixed powder, so that the size error of the silicon-aluminum oxide coating material prepared by the secondary atmospheric sintering is small, and secondary processing is not needed.

[0029] (2) The application adopts the method of one-time sintering, crushing, ball milling and secondary sintering to prepare the silicon-aluminum oxide coating material, and compared with the method of one-time sintering of the mixed powder to obtain the silicon-aluminum oxide coating material, the cracking rate of the silicon-aluminum oxide coating material produced by the application is significantly reduced, and the yield is significantly improved.

[0030] (3) The application adopts 90-99% of the mixed powder of aluminum oxide and silicon dioxide in the one-time sintering, and then adds the remaining 1-10% of the mixed powder of aluminum oxide and silicon dioxide in the secondary sintering, which can play the role of powder supplementing, effectively reduce the powder dropping rate of the silicon-aluminum oxide coating material, thereby reducing the sputtering frequency in the evaporation coating process, effectively reducing the production cost of the downstream customers, and improving the competitiveness of the product.

[0031] (4) The sintering temperature of the second sintering is lower than or equal to the sintering temperature of the first sintering, so that the size of the silicon-aluminum oxide coated film material is better controlled, and the product quality of the silicon-aluminum oxide coated film material is effectively improved. DETAILED DESCRIPTION

[0032] The application will be further described in conjunction with the embodiments below, but does not constitute any limitation to the application, and any limited modification made within the scope of the claims of the application is still within the scope of the claims of the application.

[0033] In order to describe the technical content of the application in detail, the following further describes the embodiments.

[0034] In the following embodiments, the alumina powder and the silica powder are both powders with a particle size D9 of 8 μm.

[0035] Example 1

[0036] A silicon-aluminum oxide coated film material is prepared by the following steps:

[0037] Step 1: The alumina powder and the silica powder are ball-mixed to obtain a mixed powder A with a particle size D90 of 8 μm, wherein the mass percentage of the alumina is 10%, and the mass percentage of the silica is 90%;

[0038] Step 2: 90% of the mixed powder A obtained in step 1 is heated to 1200℃ at a heating rate of 0.5℃ / min for normal pressure sintering, and the holding time is 6h, to obtain a silicon-aluminum oxide structure material;

[0039] Step 3: The silicon-aluminum oxide structure material obtained in step 2 is sequentially crushed, ball-milled and sieved to obtain a silicon-aluminum oxide structure powder with a particle size D90 of 85 μm;

[0040] Step 4: The remaining 10% of the mixed powder A in step 1 is uniformly mixed with the silicon-aluminum oxide structure powder obtained in step 3 to obtain a mixed powder B;

[0041] Step 5: The mixed powder B is formed into a tablet to obtain a green body with a size of Φ20mm*10.01mm, and the green body is heated to 1200℃ at a heating rate of 0.5℃ / min for normal pressure sintering, and the holding time is 6h, to obtain a silicon-aluminum oxide coated film material with a size of Φ19.97mm*9.99mm.

[0042] Example 2

[0043] A silicon-aluminum oxide coated film material is prepared by the following steps:

[0044] Step 1: ball-mixing alumina powder and silica powder to obtain mixed powder A with a particle size D90 of 8 μm, the mass ratio of alumina in the mixed powder A being 30%, and the mass ratio of silica being 70%;

[0045] Step 2: taking out 99% of the mixed powder A obtained in Step 1 and sintering at 1400℃ at a temperature rising rate of 5℃ / min under normal pressure, and the holding time being 3h to obtain a silica-alumina structure material;

[0046] Step 3: crushing, ball-milling and sieving the silica-alumina structure material obtained in Step 2 in sequence to obtain a silica-alumina structure powder with a particle size D90 of 85 μm;

[0047] Step 4: mixing the remaining 1% of the mixed powder A in Step 1 with the silica-alumina structure powder obtained in Step 3 to obtain mixed powder B;

[0048] Step 5: forming and tabletting the mixed powder B to obtain a green body with a size of Φ20mm*10.03mm, and sintering the green body at 1400℃ at a temperature rising rate of 5℃ / min under normal pressure, and the holding time being 3h to obtain a silica-alumina coated film material with a size of Φ19.96mm*9.99mm.

[0049] Example 3

[0050] A silica-alumina coated film material is prepared by the following steps:

[0051] Step 1: ball-mixing alumina powder and silica powder to obtain mixed powder A with a particle size D90 of 8 μm, the mass ratio of alumina in the mixed powder A being 10%, and the mass ratio of silica being 90%;

[0052] Step 2: taking out 95% of the mixed powder A obtained in Step 1 and sintering at 1300℃ at a temperature rising rate of 3℃ / min under normal pressure, and the holding time being 4h to obtain a silica-alumina structure material;

[0053] Step 3: crushing, ball-milling and sieving the silica-alumina structure material obtained in Step 2 in sequence to obtain a silica-alumina structure powder with a particle size D90 of 45 μm;

[0054] Step 4: mixing the remaining 5% of the mixed powder A in Step 1 with the silica-alumina structure powder obtained in Step 3 to obtain mixed powder B;

[0055] Step 5: The mixed powder B is formed into a tablet to obtain a green body with a size of Φ20mm*10.01, and the green body is sintered at a temperature increasing rate of 0.5℃ / min to 1300℃ for 4h to obtain a silicon-aluminum oxide coated material with a size of Φ19.98mm*9.97mm.

[0056] Example 4

[0057] A silicon-aluminum oxide coated material is prepared by the following steps:

[0058] Step 1: Alumina powder and silica powder are ball-mixed to obtain a mixed powder A with a particle size D90 of 8μm, wherein the mass percentage of alumina in the mixed powder A is 20%, and the mass percentage of silica is 80%;

[0059] Step 2: 94% of the mixed powder A obtained in step 1 is sintered at a temperature increasing rate of 3℃ / min to 1200℃ for 4h to obtain a silicon-aluminum oxide structural material;

[0060] Step 3: The silicon-aluminum oxide structural material obtained in step 2 is sequentially crushed, ball-milled and sieved to obtain a silicon-aluminum oxide structural powder with a particle size D90 of 90μm;

[0061] Step 4: The remaining 6% of the mixed powder A in step 1 is uniformly mixed with the silicon-aluminum oxide structural powder obtained in step 3 to obtain a mixed powder B;

[0062] Step 5: The mixed powder B is formed into a tablet to obtain a green body with a size of Φ20mm*10.08, and the green body is sintered at a temperature increasing rate of 0.5℃ / min to 1200℃ for 4h to obtain a silicon-aluminum oxide coated material with a size of Φ20mm*10.05mm.

[0063] Example 5

[0064] A silicon-aluminum oxide coated material is prepared by the following steps:

[0065] Step 1: Alumina powder and silica powder are ball-mixed to obtain a mixed powder A with a particle size D90 of 8μm, wherein the mass percentage of alumina in the mixed powder A is 30%, and the mass percentage of silica is 70%;

[0066] Step 2: 92% of the mixed powder A obtained in step 1 is sintered at a temperature increasing rate of 3℃ / min to 1400℃ for 4h to obtain a silicon-aluminum oxide structural material;

[0067] Step 3: The silicon-aluminum oxide structure material obtained in step 2 is subjected to crushing, ball milling and sieving in sequence to obtain a silicon-aluminum oxide structure powder with a particle size D90 of 90 μm;

[0068] Step 4: The remaining 8% by mass of the mixed powder A in step 1 is uniformly mixed with the silicon-aluminum oxide structure powder obtained in step 3 to obtain a mixed powder B;

[0069] Step 5: The mixed powder B is subjected to tabletting to obtain a green body with a size of Φ20 mm*10.10, and the green body is subjected to normal pressure sintering at a temperature rising rate of 0.5 ℃ / min to 1200 ℃ for 4 h to obtain a silicon-aluminum oxide coated material with a size of Φ19.99 mm*10.05 mm.

[0070] Comparative Example 1

[0071] A silicon-aluminum oxide coated material is prepared by the following steps:

[0072] Step 1: Alumina powder and silica powder are subjected to ball milling to obtain a mixed powder with a particle size D90 of 8 μm, wherein the mass percentage of alumina in the mixed powder is 10%, and the mass percentage of silica is 90%;

[0073] Step 2: The mixed powder is subjected to tabletting, and it is found that the single particle density of the mixed powder is small due to the fact that the mixed powder has not been subjected to primary sintering, the density of the tabletted sample is small, and the size is large. The green body is subjected to normal pressure sintering at a temperature rising rate of 0.5 ℃ / min to 1300 ℃ for 4 h, and the silicon-aluminum oxide coated material obtained by the normal pressure sintering has cracking phenomenon and becomes a waste product.

[0074] Comparative Example 2

[0075] A silicon-aluminum oxide coated material is prepared by the following steps:

[0076] Step 1: Alumina powder and silica powder are subjected to ball milling to obtain a mixed powder A with a particle size D90 of 8 μm, wherein the mass percentage of alumina in the mixed powder A is 10%, and the mass percentage of silica is 90%;

[0077] Step 2: 80% by mass of the mixed powder A obtained in step 1 is subjected to normal pressure sintering at a temperature rising rate of 3 ℃ / min to 1300 ℃ for 4 h to obtain a silicon-aluminum oxide structure material;

[0078] Step 3: The silicon-aluminum oxide structure material obtained in step 2 is subjected to crushing, ball milling and sieving in sequence to obtain a silicon-aluminum oxide structure powder with a particle size D90 of 45 μm;

[0079] Step 4: mixing the remaining 20% mass of the mixed powder A in step 1 with the silicon-aluminum oxide structured powder obtained in step 3 to obtain mixed powder B;

[0080] Step 5: forming and pressing the mixed powder B to obtain a green body with a size of Φ20mm*10.01, and then sintering the green body at a temperature rising rate of 0.5℃ / min to 1300℃ under normal pressure for 4h to obtain a silicon-aluminum oxide coated material with a size of Φ19.88mm*9.84mm.

[0081] Comparative Example 3

[0082] The same as Example 3, except that the step 5 is changed to: forming and pressing the mixed powder B to obtain a green body with a size of Φ20mm*10.01, and then sintering the green body at a temperature rising rate of 0.5℃ / min to 1400℃ under normal pressure for 4h to obtain a silicon-aluminum oxide coated material with a size of Φ19.79mm*9.89mm.

[0083] Performance test

[0084] Target density test: geometric method for testing density;

[0085] Evaporation coating test: using a TIV-1350 optical vacuum coating machine to perform evaporation coating operation on the silicon-aluminum oxide coated materials obtained in Examples 1-5 and Comparative Examples 1-4, wherein the initial vacuum degree is 3*10 -3 Pa, the baking temperature is 150℃, the coating thickness is 120nm, the coating rate is 0.5nm / s, the hole position is 3, the electron gun voltage is 8.03kw, the density setting is 7.18cm / cc, the pre-fusion output power is 230W, and the coating output power is 400W; the cracking and continuous spitting during the evaporation coating process are observed by visual inspection, and the spitting frequency is counted.

[0086] The target density test is performed on the silicon-aluminum oxide coated materials obtained in Examples 1-5 and Comparative Examples 2-3, and the results are shown in Table 1;

[0087] Table 1: Target density test results of the silicon-aluminum oxide coated materials obtained in Examples 1-5 and Comparative Examples 2-3

[0088] Group Target density g / cm 3 ]] Example 1 2.08 Example 2 2.07 Example 3 2.01 Example 4 2.03 Example 5 2.05 Comparative Example 2 2.20 Comparative Example 3 2.25

[0089] According to the results in Table 1, it can be seen that:

[0090] Since the silicon-aluminum oxide coated material prepared in Comparative Example 1 has already cracked and has a size that is too large, it is discarded and no longer subjected to performance test and comparison;

[0091] According to the data comparison of Examples 1-5 and Comparative Example 2, it can be seen that the technical scheme of the present application using 90-99% of the mixed powder A for one-time sintering, breaking, ball milling and screening, and then mixing with the remaining 1-10% of the mixed powder A for tabletting and two-time sintering can effectively control the size of the obtained silicon aluminum oxide coating material; Comparative Example 2 uses too little mixed powder A for one-time sintering, breaking, ball milling and screening, and then mixes with the remaining 20% of the mixed powder A for tabletting and two-time sintering, which results in a larger size error of the obtained silicon aluminum oxide coating material, and the density of the obtained silicon aluminum oxide coating material also becomes larger, which reduces the quality of the product, resulting in cracks and cracking in the subsequent evaporation coating application.

[0092] According to the data comparison of Examples 3 and Comparative Example 3, when the sintering temperature of the two-time sintering is higher than that of the one-time sintering, the size error of the obtained silicon aluminum oxide coating material will be significantly larger, and the density of the obtained silicon aluminum oxide coating material will also be significantly larger.

[0093] The silicon aluminum oxide coating materials obtained in Examples 1-5 and Comparative Examples 2-3 were subjected to evaporation coating test, and the results are shown in Table 2.

[0094] Table 2 Evaporation coating test results of the silicon aluminum oxide coating materials obtained in Examples 1-5 and Comparative Examples 2-3

[0095]

[0096] According to Table 2, it can be seen that:

[0097] According to the data comparison of Examples 3 and Comparative Example 2, the technical scheme of the present application using 90-99% of the mixed powder A for one-time sintering, breaking, ball milling and screening, and then mixing with the remaining 1-10% of the mixed powder A for tabletting and two-time sintering can effectively reduce the number of spatters in the pre-fusion and evaporation stages of the evaporation coating process, and effectively avoid cracks and cracking phenomena in the pre-fusion stage and the evaporation stage; while Comparative Example 2 uses too low a proportion of mixed powder A for one-time sintering, breaking, ball milling and screening, and then mixes with the remaining mixed powder A for tabletting and two-time sintering, which results in a continuous spattering phenomenon in the pre-fusion stage during the evaporation coating test, and the number of spatters is greater than 10, which greatly increases the cost, and cracks also occur in the pre-fusion stage, resulting in direct cracking in the subsequent evaporation stage, and the evaporation coating fails.

[0098] According to the data comparison of the embodiment 3 and the comparative example 3, it can be known that the temperature control of the secondary sintering and the primary sintering is one of the key points of the technical scheme of the application, when the sintering temperature of the secondary sintering is greater than the sintering temperature of the primary sintering, the prepared silicon aluminum oxide coating film material appears the continuous spattering phenomenon in the pre-fusion stage in the evaporation coating film process, and also appears the continuous spattering phenomenon in the evaporation stage, and also produces the cracking, and the spattering times is also greater than 20 times, greatly influences the quality of the product obtained by the evaporation coating film, increases the production cost of the evaporation coating film, and increases the waste rate of the evaporation coating film.

[0099] The application obtains the silicon aluminum oxide structure powder by adopting the specific proportion of the aluminum oxide and the silicon dioxide mixed powder for the primary sintering, crushing, ball milling and screening, then mixes and presses the silicon aluminum oxide structure powder and the remaining aluminum oxide and silicon dioxide mixed powder for the secondary sintering, and controls the sintering temperature of the secondary sintering not higher than the sintering temperature of the primary sintering, cooperatively controls the size of the silicon aluminum oxide coating film material and improves the product quality of the silicon aluminum oxide coating film material, and avoids the high waste rate in the subsequent evaporation coating film process.

[0100] The embodiments presented herein are only selected from the combinations of all possible embodiments. The appended claims should not be limited by the embodiments of the application. Some numerical ranges used in the claims include the sub-ranges within the ranges, and the variations in the ranges should also be covered by the appended claims.

Claims

1. A method for producing a silicon aluminum oxide coated film material, characterized by, The method comprises the following steps: Step 1: ball-mixing alumina powder and silica powder to obtain mixed powder A with a particle size D90 of less than 10 μm, wherein the mass percentage of alumina in the mixed powder A is 10-30%, and the mass percentage of silica is 70-90%; Step 2: taking out 90-99% of the mixed powder A obtained in step 1 to perform normal-pressure sintering, thereby obtaining a silicon-aluminum structure material; Step 3: sequentially crushing, ball-milling and screening the silicon-aluminum structure material obtained in step 2, thereby obtaining a silicon-aluminum structure powder with a particle size D90 of less than 100 μm; Step 4: uniformly mixing the remaining 1-10% of the mixed powder A with the silicon-aluminum structure powder obtained in step 3 to obtain mixed powder B; Step 5: forming and tabletting the mixed powder B to obtain a green body, and sintering the green body to obtain a silicon-aluminum coated film material; wherein the sintering temperature of the normal-pressure sintering in step 5 is not higher than the sintering temperature of the normal-pressure sintering in step 2; the sintering temperature of the normal-pressure sintering in step 2 is 1200-1400 ℃, the heating rate is 0.5-5 ℃ / min, and the holding time is 3-7 h; the sintering temperature of the normal-pressure sintering in step 5 is 1100-1400 ℃, the heating rate is 0.5-5 ℃ / min, and the holding time is 3-7 h.

2. The method for preparing the silicon-aluminum oxide coating material according to claim 1, characterized in that, The size of the green body in step 5 is Φ20 mm*(10±0.1) mm.

3. A silicon aluminum oxide coated material, characterized by, The silicon-aluminum coated film material is prepared by using the preparation method of claim 1 or 2.

4. The silica alumina coated material of claim 3, wherein, The size of the silicon-aluminum coated film material is Φ(20±0.1) mm*(10±0.1) mm. The size of the silicon-aluminum coated film material is Φ(20±0.1) mm*(10±0.1) mm.

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