A modified lanthanum titanate coating material and preparation method thereof

Abstract

The present invention provides a modified lanthanum titanate coating material and a preparation method thereof, and relates to the technical field of lanthanum titanate coating materials. A preparation method of a modified lanthanum titanate coating material comprises the following steps: S1, mixing a tetrabutyl titanate solution with a lanthanum nitrate solution for a solvent thermal reaction, washing and drying, and then calcining to obtain a mixture A; mixing sodium molybdate, thiourea, oxalic acid, and water evenly for a hydrothermal reaction to obtain a mixture B; S2, ball milling the mixture A and the mixture B, calcining to obtain a mixture C; S3, ball milling the mixture C, lanthanum oxide, and titanium oxide evenly, calcining, introducing a protective gas, melting treatment, and cooling to obtain a modified lanthanum titanate coating material. The modified lanthanum titanate coating material prepared by the present invention has excellent optical properties.

Description

Technical Field

[0001] The invention relates to the technical field of lanthanum titanate coating materials, and in particular to a modified lanthanum titanate coating material and a preparation method thereof. Background Art

[0002] Lanthanum titanate coating materials are widely used in the field of optical coating. Their crystal materials are suitable for high-end optical lenses due to their uniform composition, high density, and stable evaporation. Compared with ceramic particles, lanthanum titanate crystal particles have higher density, no pores, high purity, and more uniform composition, so they are more suitable for high-end optical coating. Lanthanum titanate films show superior performance in laser coating, such as low loss absorption, excellent mechanical properties, easy preparation, and stable performance. However, the refractive index and transmittance range of existing lanthanum titanate films are not ideal, which limits their application. Therefore, the development of modified lanthanum titanate coating materials is of great significance to expand its application range. Summary of the invention

[0003] Based on the technical problems existing in the background technology, the present invention proposes a modified lanthanum titanate coating material and a preparation method thereof.

[0004] The present invention provides a method for preparing a modified lanthanum titanate coating material, comprising the following steps:

[0005] S1, mixing tetrabutyl titanate solution and lanthanum nitrate solution for solvent thermal reaction, washing and drying, and then calcining to obtain mixture A; mixing sodium molybdate, thiourea, oxalic acid and water uniformly for hydrothermal reaction to obtain mixture B;

[0006] S2, ball-milling the mixture A and the mixture B, and calcining them to obtain a mixture C;

[0007] S3, ball-milling the mixture C, lanthanum oxide and titanium oxide, calcining, introducing protective gas, melting, cooling, and obtaining a modified lanthanum titanate coating material.

[0008] Preferably, in S1, the tetrabutyl titanate solution comprises tetrabutyl titanate and ethylene glycol mixed in a mass ratio of 1:(10-20), and hydrochloric acid is added dropwise to make the pH value of the solution 0.1-1.

[0009] Preferably, in S1, the lanthanum nitrate solution comprises lanthanum nitrate and water mixed in a mass ratio of (1-2):(15-20).

[0010] Preferably, in the S1, the molar ratio of tetrabutyl titanate to lanthanum nitrate is 1:1.

[0011] Preferably, in S1, the solvent heat comprises reacting at 140-160° C. for 10-12 hours.

[0012] Controlling the solvent heat temperature within a certain range is helpful for the reaction to proceed fully, so that the synthesized substance has a better crystal structure.

[0013] Preferably, in S1, washing includes centrifugal washing with an ethanol solution to remove the organic solvent on the surface of the compound, which helps to reduce the generation of impurities in the next calcination reaction, and the prepared mixture A has high purity.

[0014] Preferably, in S1, the calcination treatment comprises heating to 200-300°C at a heating rate of 1-5°C / min, keeping the temperature for 1-3h, and then heating to 600-900°C at a heating rate of 10-20°C / min, and keeping the temperature for 4-8h.

[0015] Preferably, in the above S1, grinding is further performed after the calcination treatment, and sodium hydroxide solution is added dropwise during the grinding process.

[0016] More preferably, the concentration of the sodium hydroxide solution is 0.1-1 mol / L.

[0017] Preferably, in the S1, the mass ratio of sodium molybdate, thiourea, oxalic acid and water is (5-6):(7-10):3:40.

[0018] Preferably, in S1, the hydrothermal treatment comprises treating at 160-180° C. for 15-24 h.

[0019] Preferably, in S2, the mass ratio of mixture A to mixture B is (8-12):1.

[0020] Preferably, in S2, the ball milling parameters are: ball-to-material ratio is 3:1, ball milling speed is 300-500 r / min, and ball milling time is 6-8 h.

[0021] More preferably, ammonia gas is introduced into the ball mill once every hour during the ball milling process.

[0022] Preferably, in S2, the calcination comprises reacting at 300-550° C. for 1-3 h in an ammonia atmosphere.

[0023] The ball milling and calcination in S2 help to mix mixture A and mixture B evenly, and introduce nitrogen into the mixture, so that the final product helps to improve the performance of the membrane layer.

[0024] Preferably, in S3, the molar ratio of lanthanum oxide to titanium oxide is 1:2.

[0025] Preferably, in said S3, the calcination treatment comprises calcining at 500-600° C. for 3-4 hours.

[0026] Preferably, in S3, the protective gas is argon or nitrogen.

[0027] Preferably, in said S3, the melt treatment comprises keeping the temperature at 1800-1900° C. for 3-4 hours.

[0028] Preferably, in said S3, the mixture C accounts for 10%-15% of the total mass of the modified lanthanum titanate coating material.

[0029] The present invention also provides a modified lanthanum titanate coating material prepared by the above preparation method.

[0030] The present invention also proposes an application of the modified lanthanum titanate coating material prepared by the above preparation method in the coating field.

[0031] The beneficial effects of the present invention are:

[0032] The modified lanthanum titanate coating material prepared by the preparation method of the present invention has excellent optical properties and helps to improve the refractive index and light transmittance range of the film layer. The present invention increases the refractive index to above 2.1 and the light transmittance range to 0.3-7 μm through process adjustment and formula screening. The modified lanthanum titanate coating material prepared by the preparation method of the present invention enhances product density and improves film adhesion. DETAILED DESCRIPTION

[0033] The technical solution of the present invention is described in detail through specific embodiments.

[0034] Unless otherwise specified, the materials and reagents used in the following examples can be obtained from commercial sources.

[0035] Example 1

[0036] A method for preparing a modified lanthanum titanate coating material comprises the following steps:

[0037] S1. Tetrabutyl titanate and ethylene glycol are mixed at a mass ratio of 1:15, and hydrochloric acid is added dropwise to make the pH of the solution 0.1 to obtain a tetrabutyl titanate solution; lanthanum nitrate and water are mixed at a mass ratio of 1:15 to obtain a lanthanum nitrate solution; wherein the molar ratio of tetrabutyl titanate to lanthanum nitrate is 1:1; the tetrabutyl titanate solution and the lanthanum nitrate solution are subjected to a solvent thermal reaction at 150°C for 10 hours, the ethanol solution is centrifugally washed and dried, and then calcined: the temperature is increased to 280°C at a heating rate of 3°C / min, and the temperature is kept for 1 hour, and then the temperature is increased to 750°C at a heating rate of 15°C / min, and the temperature is kept for 6 hours, and 0.5 mol / L sodium hydroxide solution is added dropwise to grind to obtain a mixture A; sodium molybdate, thiourea, oxalic acid, and water are mixed at a mass ratio of 5:8:3:40 and subjected to a hydrothermal reaction at 180°C for 16 hours to obtain a mixture B;

[0038] S2, ball milling the mixture A and the mixture B: the ball-to-material ratio is 3:1, the ball milling speed is 350 r / min, the ball milling time is 6 h, ammonia is introduced into the ball mill once every hour, and after the ball milling, the mixture is calcined at 550° C. for 2 h in an ammonia atmosphere to obtain a mixture C; the mass ratio of the mixture A to the mixture B is 10:1;

[0039] S3. The mixture C, lanthanum oxide and titanium oxide are ball-milled uniformly, and calcined at 550°C for 3 hours, and argon gas is introduced. The mixture is melt-treated at 1850°C for 3 hours, and cooled at a cooling rate of 5°C / min to obtain a modified lanthanum titanate coating material. The molar ratio of lanthanum oxide to titanium oxide is 1:2, and the mixture C accounts for 12% of the total mass of the modified lanthanum titanate coating material.

[0040] After testing, the refractive index is 2.13 and the transmittance range is 0.3-7μm.

[0041] Example 2

[0042] A method for preparing a modified lanthanum titanate coating material comprises the following steps:

[0043] S1. Tetrabutyl titanate and ethylene glycol are mixed at a mass ratio of 1:10, and hydrochloric acid is added dropwise to make the pH of the solution 0.1 to obtain a tetrabutyl titanate solution; lanthanum nitrate and water are mixed at a mass ratio of 1:15 to obtain a lanthanum nitrate solution; wherein the molar ratio of tetrabutyl titanate to lanthanum nitrate is 1:1; the tetrabutyl titanate solution and the lanthanum nitrate solution are subjected to a solvent thermal reaction at 160°C for 10 hours, the ethanol solution is centrifugally washed and dried, and then calcined: the temperature is increased to 300°C at a heating rate of 2°C / min, and the temperature is kept for 1 hour, and then the temperature is increased to 900°C at a heating rate of 15°C / min, and the temperature is kept for 4 hours, and 0.5 mol / L sodium hydroxide solution is added dropwise to grind to obtain a mixture A; sodium molybdate, thiourea, oxalic acid, and water are mixed at a mass ratio of 5:8:3:40 and subjected to a hydrothermal reaction at 180°C for 16 hours to obtain a mixture B;

[0044] S2, ball milling the mixture A and the mixture B: the ball-to-material ratio is 3:1, the ball milling speed is 400 r / min, the ball milling time is 6 h, ammonia is introduced into the ball mill once every hour, and after the ball milling, the mixture is calcined at 550° C. for 2 h in an ammonia atmosphere to obtain a mixture C; the mass ratio of the mixture A to the mixture B is 9:1;

[0045] S3. The mixture C, lanthanum oxide and titanium oxide are ball-milled uniformly, and calcined at 600°C for 3 hours, and argon gas is introduced. The mixture is melt-treated at 1850°C for 3 hours and cooled at a rate of 5°C / min to obtain a modified lanthanum titanate coating material. The molar ratio of lanthanum oxide to titanium oxide is 1:2, and the mixture C accounts for 13% of the total mass of the modified lanthanum titanate coating material.

[0046] After testing, the refractive index is 2.15 and the transmittance range is 0.3-7μm.

[0047] Example 3

[0048] A method for preparing a modified lanthanum titanate coating material comprises the following steps:

[0049] S1. Tetrabutyl titanate and ethylene glycol are mixed at a mass ratio of 1:15, and hydrochloric acid is added dropwise to make the solution pH 0.1 to obtain a tetrabutyl titanate solution; lanthanum nitrate and water are mixed at a mass ratio of 2:15 to obtain a lanthanum nitrate solution; wherein the molar ratio of tetrabutyl titanate and lanthanum nitrate is 1:1; the tetrabutyl titanate solution and the lanthanum nitrate solution are subjected to a solvent thermal reaction at 155°C for 12 hours, the ethanol solution is centrifugally washed and dried, and then calcined: the temperature is increased to 300°C at a heating rate of 3°C / min, and the temperature is kept for 1 hour, and then the temperature is increased to 800°C at a heating rate of 15°C / min, and the temperature is kept for 6 hours, and 0.5 mol / L sodium hydroxide solution is added dropwise to grind to obtain a mixture A; sodium molybdate, thiourea, oxalic acid, and water are mixed at a mass ratio of 6:8:3:40 and subjected to a hydrothermal reaction at 180°C for 16 hours to obtain a mixture B;

[0050] S2, ball milling the mixture A and the mixture B: the ball-to-material ratio is 3:1, the ball milling speed is 350 r / min, the ball milling time is 6 h, ammonia is introduced into the ball mill once every hour, and after the ball milling, the mixture is calcined at 550° C. for 2 h in an ammonia atmosphere to obtain a mixture C; the mass ratio of the mixture A to the mixture B is 12:1;

[0051] S3. The mixture C, lanthanum oxide and titanium oxide are ball-milled uniformly, and calcined at 550°C for 4 hours, and argon gas is introduced. The mixture is melt-treated at 1900°C for 3 hours and cooled at a rate of 5°C / min to obtain a modified lanthanum titanate coating material. The molar ratio of lanthanum oxide to titanium oxide is 1:2, and the mixture C accounts for 10% of the total mass of the modified lanthanum titanate coating material.

[0052] After testing, the refractive index is 2.11 and the transmittance range is 0.3-7μm.

[0053] The modified lanthanum titanate coating material prepared by the present invention has excellent optical properties

[0054] In summary, the modified lanthanum titanate coating material provided by the present invention has excellent optical properties.

[0055] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for preparing a modified lanthanum titanate coating material, characterized in that: The following steps are involved: S1, mixing tetrabutyl titanate solution and lanthanum nitrate solution for solvent thermal reaction, washing and drying, and then calcining to obtain mixture A; mixing sodium molybdate, thiourea, oxalic acid and water uniformly for hydrothermal reaction to obtain mixture B; S2, ball-milling the mixture A and the mixture B, and calcining them to obtain a mixture C; S3, ball-milling the mixture C, lanthanum oxide and titanium oxide, calcining, introducing protective gas, melting, cooling, and obtaining a modified lanthanum titanate coating material.

2. The preparation method according to claim 1, characterized in that: In the S1, the solvent heat includes reacting at 140-160°C for 10-12h; the calcination treatment includes heating to 200-300°C at a heating rate of 1-5°C / min, keeping warm for 1-3h, and then heating to 600-900°C at a heating rate of 10-20°C / min, and keeping warm for 4-8h.

3. The preparation method according to claim 1, characterized in that: In the S1, the mass ratio of sodium molybdate, thiourea, oxalic acid and water is (5-6):(7-10):3:40; the hydrothermal treatment includes treating at 160-180°C for 15-24h.

4. The preparation method according to claim 1, characterized in that: In the S2, the mass ratio of mixture A to mixture B is (8-12):1; ball milling parameters: ball-to-material ratio is 3:1, ball milling speed is 300-500 r / min, and ball milling time is 6-8 h.

5. The preparation method according to claim 1, characterized in that: In the S2, the calcination comprises reacting at 300-550° C. for 1-3 hours in an ammonia atmosphere.

6. The preparation method according to claim 1, characterized in that: In the S3, the molar ratio of lanthanum oxide to titanium oxide is 1:2; and the calcination treatment includes calcining at 500-600° C. for 3-4 hours.

7. The preparation method according to claim 1, characterized in that: In the S3, the melting treatment includes keeping the temperature at 1800-1900° C. for 3-4 hours.

8. The preparation method according to claim 1, characterized in that: In the above-mentioned S3, the mixture C accounts for 10%-15% of the total mass of the modified lanthanum titanate coating material.

9. A modified lanthanum titanate coating material, characterized in that: The invention is prepared by the preparation method according to any one of claims 1 to 8.