Aviation coating containing organic nano titanium dioxide and preparation method thereof

Abstract

The invention relates to the field of coatings, and particularly discloses an aviation coating containing organic nano titanium dioxide and a preparation method thereof.The aviation coating is prepared from, by weight, 10-20 parts of organic nano titanium dioxide, 30-45 parts of epoxy resin, 40-60 parts of organic silicon resin, 1-3 parts of dispersing agent, 5-10 parts of composite filler, 0.5-1 part of defoaming agent and 10-30 parts of water; the organic nano titanium dioxide is prepared by the following steps: dissolving titanate in an organic solution to form a titanium source solution; carboxylated graphene and starch are uniformly dispersed in an organic active agent to form a suspension; and mixing the titanium source solution and the suspension, adjusting the pH value to be acidic, stirring and reacting to generate sol, aging the sol, calcining, and grinding to obtain the organic nano titanium dioxide. The obtained aviation coating has excellent wear resistance, and a paint film does not blister, wrinkle, crack and fall off at a high temperature for 4000 hours.

Description

Technical Field

[0001] The present application relates to the field of coatings, and more specifically, to an aviation coating containing organized nano-titanium dioxide and a preparation method thereof. Background Art

[0002] Currently, aviation coatings refer to coatings used on aircraft. Based on the application area, they can be categorized as aircraft skin coatings, aircraft cabin coatings, aircraft engine coatings, aircraft component coatings, and specialized coatings (including thermal insulation coatings, fire retardant coatings, and temperature-indicating coatings). With the development of the aviation industry, higher requirements have been placed on aviation coatings. Due to the harsh flight environment and high speeds of aircraft, friction between the aircraft's surface and the airflow generates a large amount of aerodynamic heat energy. This heat energy can cause the aircraft's surface temperature to reach over 300°C and significantly damage the coating. Therefore, the development of aviation coatings with excellent thermal stability and wear resistance is crucial. Summary of the Invention

[0003] In order to improve the thermal stability and wear resistance of the coating, the present application provides an aviation coating containing organized nano-titanium dioxide and a preparation method thereof.

[0004] The present application provides an aviation coating containing organized nano-titanium dioxide using the following technical solutions:

[0005] In a first aspect, an aviation coating containing organized nano-titanium dioxide comprises the following raw materials in parts by weight: 10-20 parts of organized nano-titanium dioxide, 30-45 parts of epoxy resin, 40-60 parts of silicone resin, 1-3 parts of dispersant, 5-10 parts of composite filler, 0.5-1 part of defoamer, and 10-30 parts of water;

[0006] The organic nano-titanium dioxide is prepared by the following steps:

[0007] dissolving titanate in an organic solution to form a titanium source solution;

[0008] The carboxylated graphene and starch are uniformly dispersed in an organic surfactant to form a suspension; the raw materials used for the components of the suspension are as follows: 2-5 parts of carboxylated graphene, 1-3 parts of starch, and 10-20 parts of the organic surfactant in parts by weight;

[0009] The titanium source solution and the suspension are mixed in a volume ratio of 5:(1-2), the pH is adjusted to acidic, and the mixture is stirred to react to generate a sol. The sol is aged, calcined, and ground to obtain organic nano-titanium dioxide.

[0010] Furthermore, the titanate is tetrabutyl titanate, and the carboxylated graphene and starch are both nano-scale.

[0011] Furthermore, the pH was adjusted to acidic using glacial acetic acid.

[0012] By adopting the above technical solution, titanate is hydrolyzed to form a titanium dioxide sol. Carboxylated graphene and starch are then used to modify the titanium source solution in the presence of an organic surfactant, synergistically improving the dispersibility and high-temperature antioxidant capacity of the generated titanium dioxide. After calcination and grinding, the resulting organic nano-titanium dioxide with an organic-inorganic hybrid network can impart excellent wear resistance and high-temperature stability to the coating. During the calcination process, the carbon layer generated by starch decomposition can wrap and adsorb the TiO2 particles, inhibiting their high-temperature sintering and agglomeration, while also improving the particles' antioxidant and dispersibility. The carbon residue and carboxylated graphene jointly form a reinforced network, improving the coating's wear resistance and thermal conductivity, enhancing the coating's high-temperature stability, and reducing its wear loss.

[0013] Epoxy resin and silicone resin are used to provide a composite matrix structure, making the coating both rigid and tough. The composite filler and organic nano-titanium dioxide form a multi-level structure to enhance the density of the coating. The dispersant and defoamer can optimize the interface bonding, stabilize the dispersion of nanoparticles through the steric effect, prevent agglomeration, improve the dispersion between components, eliminate bubbles, and improve the overall performance of the coating.

[0014] Preferably, the organic active agent is a mixture of a titanate coupling agent and a hexadecyltrimethylammonium bromide solution in a mass ratio of 1:(0.4-1).

[0015] By adopting the above technical solution and selecting a titanate coupling agent and hexadecyltrimethylammonium bromide in a specific ratio as an organic active agent, not only can TiO2 and the organic resin be bridged through the Ti-O bond to enhance the interfacial bonding, but the hexadecyltrimethylammonium bromide can also reduce the surface tension, improve the dispersion effect between the components, and enhance the uniformity of the nanocomposite system. At the same time, the hydrophobic long chain of the hexadecyltrimethylammonium bromide and the hydrophilic quaternary ammonium group can form micelles, guide the orderly accumulation of the hydrolysis products of the titanium source solution, and disperse the generated titanium dioxide primary particles through the steric hindrance effect, thereby improving the crystal morphology of titanium dioxide during the calcination process and synergistically improving the crystal phase structure of the organic nano-titanium dioxide.

[0016] Preferably, the organic solvent is anhydrous ethanol, and the mass concentration of the titanium source solution is 30-50%.

[0017] By adopting the above technical solution, anhydrous ethanol is selected to dissolve titanate, and its mass concentration is optimized to ensure the production of titanium dioxide.

[0018] Preferably, the calcination is carried out under an inert atmosphere, the calcination temperature is 500-650° C., and the calcination time is 30-50 min.

[0019] By adopting the above technical solution, the calcination temperature and time are optimized, which is beneficial to the phase transformation of titanium dioxide crystal. The formation of crystal morphology is controlled by controlling the calcination time, avoiding excessive growth of titanium dioxide grains. At the same time, calcination under an inert atmosphere can ensure that the starch is fully carbonized to form a protective carbon layer and the organic active agent is fully pyrolyzed, synergistically improving the performance of organic nano-titanium dioxide.

[0020] Preferably, the composite filler includes at least two of polytetrafluoroethylene powder, mica powder, and silicon carbide.

[0021] Preferably, the composite filler is a mixture of polytetrafluoroethylene powder, mica powder and silicon carbide in a mass ratio of 1:(1-3):(0.5-1).

[0022] Furthermore, the particle size of the composite filler is micron-level.

[0023] By adopting the above technical solution, the selection of composite filler components is optimized, the friction coefficient of the coating is reduced, the airflow wear during flight is reduced, and the wear of the coating is reduced in synergy with organic nano-titanium dioxide, thereby improving the wear resistance and thermal stability of the coating.

[0024] Preferably, the dispersant includes one of BYK-163 and BYK-110.

[0025] Specifically, the dispersant is preferably BYK-163.

[0026] Preferably, the defoaming agent includes one of FAG-470 organosilicon defoaming agent and defoaming agent KS-66.

[0027] Specifically, the defoaming agent is preferably FAG-470 silicone defoaming agent.

[0028] By adopting the above technical solution, the components of the dispersant and defoamer are optimized, the compatibility and dispersion uniformity between the components are improved, the surface tension is reduced, the bubbles are quickly broken and the leveling of the coating is improved.

[0029] In a second aspect, the present application provides a method for preparing an aviation coating containing organized nano-titanium dioxide, using the following technical solution:

[0030] A method for preparing an aviation coating containing organized nano-titanium dioxide comprises the following steps:

[0031] Step 1: mixing organic nano-titanium dioxide with epoxy resin, heating and adding a catalyst dropwise to react to obtain a modified epoxy resin;

[0032] Step 2: Shear-dispersing the modified epoxy resin, silicone resin, dispersant, composite filler, defoamer and water to obtain aviation coating.

[0033] Furthermore, in step 1, the temperature is heated to 60-100°C.

[0034] Preferably, the catalyst is N-methylimidazole or dimethylbenzylamine.

[0035] By adopting the above technical solution, the organic nano-titanium dioxide and epoxy resin are first subjected to a ring-opening reaction under the action of a catalyst, and the carboxyl groups on the surface of the carboxylated graphene react with the epoxy groups of the epoxy resin to form a cross-linked network, which further improves the density of the coating and enhances the high-temperature stability and wear resistance of the coating. Finally, the coating is mixed with other components and sheared and dispersed to ensure that the components are evenly dispersed, avoid sedimentation or agglomeration, and improve the quality of the coating.

[0036] In summary, the present application has the following beneficial effects: the present application adopts a composite resin system in conjunction with nano-scale organic nano-titanium dioxide and micron-scale composite fillers to significantly improve the high-temperature stability and wear resistance of the coating and reduce the coating wear. DETAILED DESCRIPTION

[0037] The embodiments of the present invention will be described in detail below with reference to the examples, but it will be understood by those skilled in the art that the following examples are only used to illustrate the present invention and should not be construed as limiting the scope of the present invention. The specific conditions not specified in the examples are carried out according to conventional conditions or the conditions recommended by the manufacturer. The reagents or instruments used are conventional products that can be purchased commercially without specifying the manufacturer. Carboxylated graphene was purchased from Chengdu Jiacai Technology Co., Ltd., epoxy resin was purchased from Shandong Jinhong New Material Technology Co., Ltd., and silicone resin was purchased from Jinan Jibin Chemical Co., Ltd.

[0038] Example

[0039] Example 1

[0040] The aviation coating containing organized nano-titanium dioxide includes the following raw materials: 18 kg of organized nano-titanium dioxide, 40 kg of epoxy resin, 52 kg of silicone resin, 2.2 kg of dispersant, 8 kg of composite filler, 0.7 kg of defoamer, and 23 kg of water;

[0041] The dispersant is BYK-163, and the defoamer is FAG-470 silicone defoamer;

[0042] The composite filler is a mixture of polytetrafluoroethylene powder, mica powder and silicon carbide in a mass ratio of 1:2:0.6

[0043] Organic nano-titanium dioxide is prepared by the following steps:

[0044] Dissolving tetrabutyl titanate in anhydrous ethanol to form a titanium source solution with a mass concentration of 40%;

[0045] 3.8 kg of carboxylated graphene and 2 kg of starch were evenly dispersed in 16 kg of an organic active agent to form a suspension; the organic active agent was a titanate coupling agent and hexadecyltrimethylammonium bromide solution with a mass ratio of 1:0.7.

[0046] The titanium source solution and the suspension were mixed in a volume ratio of 5:1.3, the pH was adjusted to 5 with glacial acetic acid, and the reaction was stirred to generate a sol. After aging, the sol was calcined under an inert atmosphere at a temperature of 620°C for 40 minutes. After grinding to the nanoscale, organic nano-titanium dioxide was obtained.

[0047] The preparation method of aviation coating containing organized nano titanium dioxide comprises the following steps:

[0048] Step 1: Mixing organic nano-titanium dioxide and epoxy resin, heating to 90° C. and adding catalyst N-methylimidazole dropwise to react to obtain modified epoxy resin;

[0049] Step 2: Shear and disperse the modified epoxy resin, silicone resin, dispersant, composite filler, defoamer and water at a rotation speed of 1500 rpm to obtain an aviation coating.

[0050] Example 2

[0051] The aviation coating containing organized nano-titanium dioxide includes the following raw materials: 10kg of organized nano-titanium dioxide, 30kg of epoxy resin, 60kg of silicone resin, 1kg of dispersant, 5kg of composite filler, 1kg of defoamer, and 30kg of water;

[0052] The dispersant is BYK-110 and the defoamer is KS-66 defoamer;

[0053] The composite filler is a mixture of polytetrafluoroethylene powder and silicon carbide in a mass ratio of 1:1;

[0054] Organic nano-titanium dioxide is prepared by the following steps:

[0055] Dissolving tetrabutyl titanate in anhydrous ethanol to form a titanium source solution with a mass concentration of 30%;

[0056] 2kg of carboxylated graphene and 3kg of starch are evenly dispersed in 10kg of an organic active agent to form a suspension; the organic active agent is a titanate coupling agent and hexadecyltrimethylammonium bromide solution in a mass ratio of 1:1.

[0057] The titanium source solution and the suspension were mixed in a volume ratio of 5:2, the pH was adjusted to 5 with glacial acetic acid, and the reaction was stirred to generate a sol. After aging, the sol was calcined under an inert atmosphere at a calcination temperature of 500°C for 50 minutes. After grinding to the nanoscale, organic nano-titanium dioxide was obtained.

[0058] The preparation method of aviation coating containing organized nano titanium dioxide comprises the following steps:

[0059] Step 1: Mixing organic nano-titanium dioxide and epoxy resin, heating to 60° C. and adding catalyst N-methylimidazole dropwise to react to obtain modified epoxy resin;

[0060] Step 2: Shear and disperse the modified epoxy resin, silicone resin, dispersant, composite filler, defoamer and water at a rotation speed of 1500 rpm to obtain an aviation coating.

[0061] Example 3

[0062] The difference from Example 1 is that the organic nano-titanium dioxide is prepared by the following steps:

[0063] Dissolving tetrabutyl titanate in anhydrous ethanol to form a titanium source solution with a mass concentration of 50%;

[0064] 5 kg of carboxylated graphene and 1 kg of starch were evenly dispersed in 20 kg of an organic active agent to form a suspension; the organic active agent was a titanate coupling agent and hexadecyltrimethylammonium bromide solution with a mass ratio of 1:0.4.

[0065] The titanium source solution and the suspension were mixed in a volume ratio of 5:1, the pH was adjusted to 5 with glacial acetic acid, and the mixture was stirred to react to form a sol. The sol was aged and then calcined under an inert atmosphere at a temperature of 580°C for 30 minutes. After grinding to nanoscale, organic nano-titanium dioxide was obtained.

[0066] The rest are the same as in Example 1.

[0067] Example 4

[0068] The difference from Example 1 is that in the preparation step of the organic nano-titanium dioxide, the organic active agent is a titanate coupling agent, and the rest is the same as Example 1.

[0069] Example 5

[0070] The difference from Example 1 is that the composite filler includes mica powder and zinc oxide in a mass ratio of 2:1, and the rest is the same as Example 1.

[0071] Example 6

[0072] The difference from Example 1 is that the composite filler is a mixture of polytetrafluoroethylene powder, mica powder and silicon carbide in a mass ratio of 1:3:0.5, and the rest is the same as Example 1.

[0073] Comparative Example

[0074] Comparative Example 1

[0075] The difference from Example 1 is that nano titanium dioxide powder is uniformly dispersed in an organic active agent to obtain nano titanium dioxide, and the above nano titanium dioxide replaces the organic nano titanium dioxide in Example 1. The rest is the same as Example 1.

[0076] Comparative Example 2

[0077] The difference from Example 1 is that in the preparation step of organic nano-titanium dioxide, carboxylated graphene is replaced by graphene, the organic active agent is a silane coupling agent; the volume ratio of the titanium source solution and the suspension is 5:3, and the rest is the same as Example 1.

[0078] Comparative Example 3

[0079] The difference from Example 1 is that calcium carbonate is used instead of the composite filler, and the rest is the same as Example 1.

[0080] Comparative Example 4

[0081] The difference from Example 1 is that the preparation method of the aviation coating containing organized nano-titanium dioxide includes the following steps: shearing and dispersing the organized nano-titanium dioxide, epoxy resin, silicone resin, dispersant, composite filler, defoaming agent and water at a rotation speed of 1500 rpm to obtain the aviation coating; the raw material components are the same as those in Example 1.

[0082] Performance testing

[0083] Detection method / test method

[0084] The coatings obtained in Examples 1-6 and Comparative Examples 1-4 were evenly sprayed onto the sample to form a coating with a coating thickness of 100 μm. The coating abrasion was tested according to GB / T 1768-2006 "Paints and varnishes - Determination of abrasion resistance - Rotating rubber grinding wheel method". The sample containing the coating was placed in air and heated to 400°C at a rate of 10°C / min. The changes in the coating surface of the sample and the holding time were observed and recorded. The results are shown in Table 1.

[0085] Table 1

[0086] Wear mg / 1000r High temperature stability Example 1 3.3 4000h paint film does not bubble, wrinkle, crack or fall off Example 2 4.2 3900h paint film does not bubble, wrinkle, crack or fall off Example 3 3.9 3940h paint film does not bubble, wrinkle, crack or fall off Example 4 3.6 3970h paint film does not bubble, wrinkle, crack or fall off Example 5 4 3920h paint film does not bubble, wrinkle, crack or fall off Example 6 3.5 3980 paint film does not bubble, wrinkle, crack or fall off Comparative Example 1 21.5 2500h paint film does not bubble, wrinkle, crack or fall off Comparative Example 2 17.4 3200h paint film does not bubble, wrinkle, crack or fall off Comparative Example 3 11.9 3450h paint film does not bubble, wrinkle, crack or fall off Comparative Example 4 10.6 3680h paint film does not bubble, wrinkle, crack or fall off

[0087] From Examples 1-6 and Table 1, it can be seen that the aviation coating obtained by adopting the specific component ratio and preparation method of this application has excellent wear resistance, and the paint film does not bubble, wrinkle, crack or fall off for up to 4000 hours at high temperature.

[0088] Through Example 1 and Comparative Examples 1-2 and in combination with Table 1, it can be seen that the preparation steps of the organic nano-titanium dioxide and the raw material components used are crucial to the performance of the coating. This is because the titanium source solution can be modified by using carboxylated graphene and starch under the action of an organic active agent, synergistically improving the dispersibility and high-temperature antioxidant capacity of the generated titanium dioxide. The organic nano-titanium dioxide with an organic-inorganic hybrid network obtained after calcination and grinding can give the coating excellent wear resistance and high-temperature stability. During the calcination process, the carbon layer generated by the decomposition of starch can wrap and adsorb TiO2 particles, inhibiting their high-temperature sintering and agglomeration, while improving the oxidation resistance and dispersibility of the particles. The carbon residue and the carboxylated graphene jointly construct an enhanced network, improving the wear resistance and thermal conductivity of the coating, improving the high-temperature stability of the coating and reducing its wear loss.

[0089] Through Example 1 and Comparative Example 3 and in combination with Table 1, it can be seen that in Comparative Example 3, calcium carbonate is used instead of the composite filler, and the wear of the coating is significantly increased and the high-temperature stability is also reduced. This is because the composite filler and the organic nano-titanium dioxide can form a multi-level structure in the composite resin matrix, which enhances the density of the coating, synergistically reduces the wear of the coating, and improves the wear resistance and thermal stability of the coating.

[0090] Through Example 1 and Comparative Example 4 in combination with Table 1, it can be seen that when the raw material components are directly sheared, mixed and dispersed, the resulting coating has poor wear resistance and high temperature stability after forming a coating. This is because the organic nano-titanium dioxide contains carboxylated graphene, and the carboxyl groups on the surface of the carboxylated graphene react with the epoxy groups of the epoxy resin under the action of a catalyst and heating to form a cross-linked network, which further improves the density of the coating and improves the high temperature stability and wear resistance of the coating.

[0091] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. An aviation coating containing organized nano-titanium dioxide, characterized in that: The method comprises the following raw materials in parts by weight: 10-20 parts of organic nano-titanium dioxide, 30-45 parts of epoxy resin, 40-60 parts of silicone resin, 1-3 parts of dispersant, 5-10 parts of composite filler, 0.5-1 part of defoaming agent, and 10-30 parts of water; The organic nano-titanium dioxide is prepared by the following steps: dissolving titanate in an organic solution to form a titanium source solution; The carboxylated graphene and starch are uniformly dispersed in an organic surfactant to form a suspension; the raw materials used for the components of the suspension are as follows: 2-5 parts of carboxylated graphene, 1-3 parts of starch, and 10-20 parts of the organic surfactant in parts by weight; The titanium source solution and the suspension are mixed in a volume ratio of 5:(1-2), the pH is adjusted to acidic, and the mixture is stirred to react to generate a sol. The sol is aged, calcined, and ground to obtain organic nano-titanium dioxide.

2. The aviation coating containing organized nano-titanium dioxide according to claim 1, characterized in that: The organic active agent is a mixture of a titanate coupling agent and a hexadecyltrimethylammonium bromide solution in a mass ratio of 1:(0.4-1).

3. The aviation coating containing organized nano-titanium dioxide according to claim 2, characterized in that: The organic solvent is anhydrous ethanol, and the mass concentration of the titanium source solution is 30-50%.

4. The aviation coating containing organized nano-titanium dioxide according to claim 3, characterized in that: The calcination is carried out in an inert atmosphere at a temperature of 500-650° C. and a calcination time of 30-50 minutes.

5. The aviation coating containing organized nano-titanium dioxide according to claim 1, characterized in that: The composite filler includes at least two of polytetrafluoroethylene powder, mica powder and silicon carbide.

6. The aviation coating containing organized nano-titanium dioxide according to claim 5, characterized in that: The composite filler is a mixture of polytetrafluoroethylene powder, mica powder and silicon carbide in a mass ratio of 1:(1-3):(0.5-1).

7. The aviation coating containing organized nano-titanium dioxide according to claim 1, characterized in that: The dispersant includes one of BYK-163 and BYK-110.

8. The aviation coating containing organized nano-titanium dioxide according to claim 1, characterized in that: The defoaming agent includes one of FAG-470 organosilicon defoaming agent and defoaming agent KS-66.

9. The method for preparing an aviation coating containing organized nano-titanium dioxide according to any one of claims 1 to 8, characterized in that: The following steps are involved: Step 1: mixing organic nano-titanium dioxide with epoxy resin, heating and adding a catalyst dropwise to react to obtain a modified epoxy resin; Step 2: Shear-dispersing the modified epoxy resin, silicone resin, dispersant, composite filler, defoamer and water to obtain aviation coating.

10. The method for preparing an aviation coating containing organized nano-titanium dioxide according to claim 9, characterized in that: The catalyst is N-methylimidazole or dimethylbenzylamine.