Preparation method and use method of high-transparency polyurea-polysiloxane anti-icing / deicing coating sprayed at low pressure

Abstract

The invention discloses a preparation method and a use method of a low-pressure sprayed high-transparency polyurea-polysiloxane anti-icing / deicing coating, and belongs to the field of anti-icing / deicing coatings. The invention aims to solve the problems that an existing anti-icing / deicing coating cannot have excellent anti-icing property, excellent deicing property in a low-temperature and high-humidity environment, excellent mechanical property, corrosion resistance and transparency at the same time, and solves the problems that an existing polyurea coating is rapid in curing and needs special equipment for high-pressure spraying. The method comprises the following steps: 1, synthesizing modified amino silicon oil; 2, preparing a compound solvent; 3, synthesizing a semi-prepolymer of the component A; and 4, preparing a component B of the chain extender. The application method comprises the following steps: mixing the semi-prepolymer component A and the chain extender component B of the polyurea-polysiloxane anti-icing / deicing coating to obtain a coating, spraying the coating on the surface of a material, preliminarily curing, and gradually heating and curing. The invention relates to preparation and application of the high-transparency polyurea-polysiloxane anti-icing / deicing coating for low-pressure spraying.

Description

Technical Field

[0001] The invention belongs to the field of anti-icing / de-icing coatings. Background Art

[0002] Icing is one of the common phenomena in the natural environment. Ice is generally very firmly adhered and difficult to remove. If not handled properly, it often has catastrophic consequences, seriously threatening the normal operation of important equipment such as aircraft, wind turbine blades, bridge cables, polar scientific research equipment, high-voltage power lines, cold-region high-speed railways, buildings, ships, and even causing huge economic losses and casualties.

[0003] In order to solve the problem of icing, people have developed a variety of deicing methods that can reduce ice adhesion. According to different principles, they can be divided into two categories: active and passive methods. Active methods include heating deicing, mechanical deicing and chemical deicing. They have low deicing efficiency, high energy consumption, harm to the environment and require regular operation. Passive methods use the properties of the material itself to deicer, do not require external energy input, have a long duration, and have almost no requirements for equipment, which has attracted widespread attention from researchers. At present, passive methods can be divided into two ideas: one is to inhibit the formation of ice on the surface, and the other is to reduce the adhesion of ice to the surface. Today's passive anti-icing / deicing research focuses on low ice adhesion anti-icing / deicing coatings-using reasonable surface structure and chemical design to reduce the adhesion of ice, so that ice can be removed by wind or self-weight. However, today's anti-icing / deicing coatings have problems such as poor durability and poor mechanical properties. They are prone to physical damage and chemical corrosion under harsh outdoor environmental conditions, which greatly reduces the anti-icing / deicing performance. In addition, traditional anti-icing / deicing coatings are mostly opaque coatings, which are severely limited in scenarios where transparency is required.

[0004] Polyurea coating is an elastomer formed by the reaction of isocyanate components and amino compound components. It can be divided into pure polyurea and semi-polyurea according to the presence of carbamate. Polyurea coating has the characteristics of rapid solidification, insensitivity to temperature and humidity, strong mechanical properties, and excellent durability. It is a very promising anti-icing / deicing coating matrix. However, the surface energy of conventional polyurea coating is very high, it does not have anti-icing / deicing properties, has low transparency, and generally requires two-component spraying equipment. It has a certain threshold for use and also places high requirements on the construction site. If the polyurea coating can be optimized, the anti-icing / deicing function can be introduced, and the transparency of the material can be improved, it is expected to solve the problems of poor durability and low transparency of anti-icing / deicing coatings. It can be seen that the development of a polyurea anti-icing / deicing coating with anti-icing / deicing properties, excellent durability, up-to-standard transparency, and low threshold for use is of high value to the development of the anti-icing / deicing coating field. Summary of the invention

[0005] The present invention aims to solve the problem that existing anti-icing / deicing coatings cannot simultaneously possess excellent anti-icing properties, excellent deicing properties in low-temperature and high-humidity environments, excellent mechanical properties, corrosion resistance and transparency, and to solve the problem that existing polyurea coatings cure quickly and require high-pressure spraying with professional equipment, thereby providing a preparation method and use method of a low-pressure sprayed high-transparency polyurea-polysiloxane anti-icing / deicing coating.

[0006] A method for preparing a low-pressure sprayed high-transparency polyurea-polysiloxane anti-icing / deicing coating, wherein the low-pressure sprayed high-transparency polyurea-polysiloxane anti-icing / deicing coating is composed of a semi-prepolymer component A of the polyurea-polysiloxane anti-icing / deicing coating and a chain extender component B, and is prepared according to the following steps:

[0007] 1. Synthesis of modified amino silicone oil:

[0008] The aminopropyl-terminated polydimethylsiloxane and diethyl maleate are subjected to an N-hetero-Michael addition reaction to obtain a modified amino silicone oil containing a secondary amine group;

[0009] 2. Preparation of compound solvent:

[0010] Tetrahydrofuran, xylene and N,N-dimethylformamide are mixed to obtain a gradient volatile composite solvent;

[0011] 3. Synthesis of semi-prepolymer of component A:

[0012] The diphenylmethane diisocyanate is reacted with a modified amino silicone oil containing a secondary amine group to obtain a semi-prepolymer component A of a polyurea-polysiloxane anti-icing / de-icing coating;

[0013] 4. Preparation of chain extender component B:

[0014] The chain extender, amino silicone oil and a gradient volatilized composite solvent are mixed to obtain a chain extender B component.

[0015] A method for using a low-pressure spray high-transparency polyurea-polysiloxane anti-icing / de-icing coating, which is carried out according to the following steps:

[0016] The semi-prepolymer A component and the chain extender B component of the polyurea-polysiloxane anti-icing / deicing coating are mixed in a mass ratio of (3-5):1 to obtain the coating, the coating is sprayed on the surface of the material and initially cured, and then gradually heated to cure, thereby completing the use of the high-transparency polyurea-polysiloxane anti-icing / deicing coating sprayed at a low pressure.

[0017] The beneficial effects of the present invention are:

[0018] The present invention can adjust the anti-icing / de-icing ability and mechanical properties of the coating by adjusting the ratio of polysiloxane and chain extender, and can make component A store stably for a long time by introducing modified polysiloxane, and can adjust the surface drying and actual drying time by adjusting the content of each component of the solvent. At the same time, the introduction of linear long chains of polysiloxane significantly improves the hydrophobicity and anti-icing / de-icing properties of the polyurea coating. The present invention has a simple and efficient reaction process, stable component performance, simple spraying operation, no need for professional equipment, and has good application and promotion prospects.

[0019] 1. The process flow is very simple. The polyurea-polysiloxane anti-icing / de-icing coating of the present invention can be prepared by only two steps of synthesis, and the process flow is simple, avoiding delicate operation steps, and can be repeatedly fed and discharged, which is suitable for large-scale production.

[0020] 2. The coating has low viscosity and is suitable for low-pressure spraying. Due to the presence of the compounded solvent, the viscosity of the polyurea-polysiloxane anti-icing / de-icing coating of the present invention is very low, and spraying can be completed by a handheld spray gun without the need for complex high-pressure two-component spraying equipment, which greatly reduces the threshold for the use of anti-icing / de-icing coatings. It can be brushed or sprayed, and is suitable for the construction of large components.

[0021] 3. Long storage time and controllable operation time. The A and B components of the two-component coating can be stored for a long time in a sealed state; after the two are mixed, due to the presence of the compounding solvent, they only need to be kept away from the open to avoid curing, and the performance is stable.

[0022] 4. Moderate curing rate and fast surface drying. The compound solvent contained in the coating has been carefully designed. The fast-volatile components are surface-dry after evaporation, and the slow-volatile parts evaporate slowly to avoid bubbles inside that affect transparency. The coating is completely cured after high-temperature curing.

[0023] 5. High transparency and wide application. After curing, the coating becomes a transparent soft elastic body, which can meet various usage scenarios with high requirements for transparency and has a wider application space.

[0024] 6. The anti-icing / de-icing coating formed after the polyurea-polysiloxane anti-icing / de-icing coating is cured has excellent anti-icing properties, excellent de-icing properties in low temperature and high humidity environments, excellent mechanical properties, corrosion resistance and transparency.

[0025] The invention discloses a preparation method and a use method of a high-transparency polyurea-polysiloxane anti-icing / de-icing coating for low-pressure spraying. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a physical picture of the polyurea-polysiloxane anti-icing / de-icing coating prepared in Example 1;

[0027] Figure 2This is a contact angle test diagram of the polyurea-polysiloxane anti-icing / de-icing coating prepared in Example 1;

[0028] Figure 3 This is a transparency photograph of the polyurea-polysiloxane anti-icing / de-icing coating prepared in Example 1. DETAILED DESCRIPTION

[0029] The technical solution of the present invention is not limited to the specific implementation modes listed below, but also includes any combination of the specific implementation modes.

[0030] Specific implementation method 1: A method for preparing a high-transparency polyurea-polysiloxane anti-icing / deicing coating by low-pressure spraying described in this implementation method, wherein the high-transparency polyurea-polysiloxane anti-icing / deicing coating by low-pressure spraying is composed of a semi-prepolymer component A of the polyurea-polysiloxane anti-icing / deicing coating and a chain extender component B, and is prepared according to the following steps:

[0031] 1. Synthesis of modified amino silicone oil:

[0032] The aminopropyl-terminated polydimethylsiloxane and diethyl maleate are subjected to an N-hetero-Michael addition reaction to obtain a modified amino silicone oil containing a secondary amine group;

[0033] 2. Preparation of compound solvent:

[0034] Tetrahydrofuran, xylene and N,N-dimethylformamide are mixed to obtain a gradient volatile composite solvent;

[0035] 3. Synthesis of semi-prepolymer of component A:

[0036] The diphenylmethane diisocyanate is reacted with a modified amino silicone oil containing a secondary amine group to obtain a semi-prepolymer component A of a polyurea-polysiloxane anti-icing / de-icing coating;

[0037] 4. Preparation of chain extender component B:

[0038] The chain extender, amino silicone oil and a gradient volatilized composite solvent are mixed to obtain a chain extender B component.

[0039] The beneficial effects of this embodiment are:

[0040] This embodiment can adjust the anti-icing / de-icing ability and mechanical properties of the coating by adjusting the ratio of polysiloxane and chain extender, and can make component A store stably for a long time by introducing modified polysiloxane, and can adjust the surface drying and actual drying time by adjusting the content of each component of the solvent. At the same time, the introduction of long linear chains of polysiloxane significantly improves the hydrophobicity and anti-icing / de-icing properties of the polyurea coating. This embodiment has a simple and efficient reaction process, stable component performance, simple spraying operation, no need for professional equipment, and has good application and promotion prospects.

[0041] 1. The process is very simple. The polyurea-polysiloxane anti-icing / de-icing coating described in this embodiment can be prepared in only two steps of synthesis, has a simple process, avoids delicate operation steps, can be repeatedly fed and discharged, and is suitable for large-scale production.

[0042] 2. The coating has low viscosity and is suitable for low-pressure spraying. Due to the presence of the compounded solvent, the polyurea-polysiloxane anti-icing / de-icing coating described in this embodiment has a very low viscosity and can be sprayed with a handheld spray gun without the need for complex high-pressure two-component spraying equipment, which greatly reduces the threshold for the use of anti-icing / de-icing coatings. It can be applied by brush or spray, and is suitable for the construction of large components.

[0043] 3. Long storage time and controllable operation time. The A and B components of the two-component coating can be stored for a long time in a sealed state; after the two are mixed, due to the presence of the compounding solvent, they only need to be kept away from the open to avoid curing, and the performance is stable.

[0044] 4. Moderate curing rate and fast surface drying. The compound solvent contained in the coating has been carefully designed. The fast-volatile components are surface-dry after evaporation, and the slow-volatile parts evaporate slowly to avoid bubbles inside that affect transparency. The coating is completely cured after high-temperature curing.

[0045] 5. High transparency and wide application. After curing, the coating becomes a transparent soft elastic body, which can meet various usage scenarios with high requirements for transparency and has a wider application space.

[0046] 6. The anti-icing / de-icing coating formed after the polyurea-polysiloxane anti-icing / de-icing coating is cured has excellent anti-icing properties, excellent de-icing properties in low temperature and high humidity environments, excellent mechanical properties, corrosion resistance and transparency.

[0047] Specific embodiment 2: This embodiment is different from the specific embodiment 1 in that the N-hetero Michael addition reaction described in step 1 is specifically carried out according to the following steps:

[0048] ① In a nitrogen atmosphere and a rotation speed of 100 rpm to 500 rpm, the aminopropyl-terminated polydimethylsiloxane is heated to 40°C to 60°C, and then diethyl maleate is added dropwise to mix evenly in a nitrogen atmosphere, a rotation speed of 100 rpm to 500 rpm and a temperature of 40°C to 60°C to obtain a mixed solution;

[0049] ② In a nitrogen atmosphere and a rotation speed of 100 rpm to 500 rpm, the mixed solution is slowly heated to 80°C to 100°C, and then refluxed with condensed water for 8h to 14h in a nitrogen atmosphere, a rotation speed of 100 rpm to 500 rpm and a temperature of 80°C to 100°C. After the reflux is completed, heating and cooling are stopped to obtain a modified amino silicone oil containing a secondary amine group. The rest is the same as the first embodiment.

[0050] Specific embodiment 3: This embodiment is different from specific embodiment 1 or 2 in that: the dropping speed of diethyl maleate described in step 1① is 1 drop / s to 2 drops / s; the mass ratio of aminopropyl-terminated polydimethylsiloxane to diethyl maleate described in step 1① is 1:(0.1 to 0.3); step 1② is carried out in a nitrogen atmosphere and a rotation speed of 100rpm to 500rpm, and the mixed solution is slowly heated to 80℃ to 100℃ at a heating rate of 5℃ / min to 15℃ / min. The rest is the same as specific embodiment 1 or 2.

[0051] Specific embodiment 4: This embodiment differs from specific embodiments 1 to 3 in that the mass ratio of tetrahydrofuran to xylene in step 2 is (1 to 4): 1; the mass ratio of N,N-dimethylformamide to xylene in step 2 is 1:(1 to 2). Other aspects are the same as specific embodiments 1 to 3.

[0052] Specific embodiment 5: This embodiment differs from specific embodiments 1 to 4 in that the reaction of isocyanate with modified amino silicone oil containing secondary amine groups in step 3 is specifically carried out according to the following steps:

[0053] ① Dissolve diphenylmethane diisocyanate in a gradient volatilization compound solvent, and then stir for 10 min to 30 min in a nitrogen atmosphere, a rotation speed of 100 rpm to 500 rpm, and an ice bath at a temperature of 0°C to 5°C to obtain an MDI solution;

[0054] ② Evenly mix the modified amino silicone oil containing secondary amine groups and the gradient volatilized composite solvent to obtain a modified amino silicone oil solution;

[0055] ③ In a nitrogen atmosphere and a rotation speed of 100 rpm to 500 rpm, the modified amino silicone oil solution is slowly added dropwise to the MDI solution. After the addition is completed, the reaction device is sealed and stirred for 6 h to 12 h at a rotation speed of 100 rpm to 500 rpm and an ice bath at a temperature of 0°C to 5°C. After the reaction is completed, the liquid in the reaction device is collected to obtain a clear and transparent colorless solution, i.e., the semi-prepolymer A component of the polyurea-polysiloxane anti-icing / de-icing coating. The rest is the same as the specific embodiments one to four.

[0056] Specific embodiment 6: This embodiment is different from the specific embodiments 1 to 5 in that: the diphenylmethane diisocyanate described in step 3① is specifically heated to melt at a temperature of 50℃~70℃; the mass ratio of diphenylmethane diisocyanate described in step 3① to the gradient volatilization compound solvent is 1:(3~5); the mass ratio of the modified amino silicone oil containing secondary amine group described in step 3② to the gradient volatilization compound solvent is 1:(0.1~0.2); the mass ratio of the modified amino silicone oil solution described in step 3③ to the MDI solution is 1:(0.6~0.9); the dripping speed of the modified amino silicone oil solution described in step 3③ is 1 drop / s~2 drops / s. The rest is the same as the specific embodiments 1 to 5.

[0057] Specific embodiment 7: This embodiment is different from specific embodiments 1 to 6 in that: the chain extender described in step 4 is 4,4'-di-sec-butylaminodiphenylmethane, 4,4'-diaminodiphenylmethane (MDA), p-phenylenediamine, m-phenylenediamine, hexamethylenediamine or diethyltoluenediamine, etc.; the amino silicone oil described in step 4 is bis-aminopropyl polydimethylsiloxane. Others are the same as specific embodiments 1 to 6.

[0058] Specific embodiment eight: This embodiment differs from specific embodiments one to seven in that the mass ratio of the chain extender to the amino silicone oil in step four is (0.2-0.5):1; the mass ratio of the chain extender to the gradient volatilization compound solvent in step four is (0.2-0.5):1. The rest is the same as specific embodiments one to seven.

[0059] Specific embodiment 9: This embodiment is a method for using a low-pressure spray high-transparency polyurea-polysiloxane anti-icing / de-icing coating, which is carried out in the following steps:

[0060] The semi-prepolymer A component and the chain extender B component of the polyurea-polysiloxane anti-icing / de-icing coating are mixed in a mass ratio of (3-5):1 to obtain the coating, the coating is sprayed on the surface of the material and initially cured, and then gradually heated and cured, thereby completing the use of the high-transparency polyurea-polysiloxane anti-icing / de-icing coating sprayed at a low pressure.

[0061] Specific embodiment 10: This embodiment differs from specific embodiment 9 in that: the spraying is specifically performed at room temperature and a pressure of 1MPa to 4MPa, and the spraying thickness is 100μm to 300μm; the preliminary curing is specifically performed at room temperature for 3h to 6h; the gradual temperature increase curing is specifically performed at a temperature of 50℃ to 70℃ for 3h to 6h, and then at a temperature of 80℃ to 100℃ for 6h to 10h. The rest is the same as specific embodiment 9.

[0062] The following examples are used to verify the beneficial effects of the present invention:

[0063] Embodiment 1:

[0064] A method for preparing a low-pressure sprayed high-transparency polyurea-polysiloxane anti-icing / deicing coating, wherein the low-pressure sprayed high-transparency polyurea-polysiloxane anti-icing / deicing coating is composed of a semi-prepolymer component A of the polyurea-polysiloxane anti-icing / deicing coating and a chain extender component B, and is prepared according to the following steps:

[0065] 1. Synthesis of modified amino silicone oil:

[0066] ① In a nitrogen atmosphere and at a rotation speed of 200 rpm, the aminopropyl-terminated polydimethylsiloxane was heated to 55°C, and then diethyl maleate was added dropwise at a drop speed of 1 drop / s under the conditions of a nitrogen atmosphere, a rotation speed of 200 rpm and a temperature of 55°C to obtain a mixed solution;

[0067] The mass ratio of the aminopropyl-terminated polydimethylsiloxane to diethyl maleate is 1:0.175;

[0068] ② In a nitrogen atmosphere and a rotation speed of 200 rpm, the mixed solution was slowly heated to 95°C at a heating rate of 5°C / min, and then refluxed with condensed water for 12 hours in a nitrogen atmosphere, a rotation speed of 200 rpm and a temperature of 95°C. After the reflux, heating and cooling were stopped to obtain a modified amino silicone oil containing a secondary amine group;

[0069] 2. Preparation of compound solvent:

[0070] Tetrahydrofuran, xylene and N,N-dimethylformamide are mixed to obtain a gradient volatile composite solvent;

[0071] The mass ratio of tetrahydrofuran to xylene is 2:1.4; the mass ratio of N,N-dimethylformamide to xylene is 1:1.4;

[0072] 3. Synthesis of semi-prepolymer of component A:

[0073] ① Dissolve diphenylmethane diisocyanate in a gradient volatilization composite solvent, and then stir for 30 minutes under a nitrogen atmosphere, a rotation speed of 200 rpm, and an ice bath at a temperature of 0°C to 5°C to obtain an MDI solution;

[0074] The diphenylmethane diisocyanate is specifically prepared by heating the diphenylmethane diisocyanate to melt at a temperature of 60° C. The mass ratio of the diphenylmethane diisocyanate to the gradient volatilization composite solvent is 1:3.75;

[0075] ② Evenly mix the modified amino silicone oil containing secondary amine groups and the gradient volatilized composite solvent to obtain a modified amino silicone oil solution;

[0076] The mass ratio of the modified amino silicone oil containing secondary amine groups to the gradient volatilization compound solvent is 5:1;

[0077] ③ Under the conditions of nitrogen atmosphere and rotation speed of 200 rpm, the modified amino silicone oil solution was slowly added to the MDI solution at a drop rate of 1 drop / s. After the addition was completed, the reaction device was sealed and stirred for 8 hours at a rotation speed of 200 rpm and an ice bath at a temperature of 0°C to 5°C. After the reaction was completed, the liquid in the reaction device was collected to obtain a clear and transparent colorless solution, i.e., the semi-prepolymer A component of the polyurea-polysiloxane anti-icing / de-icing coating;

[0078] The mass ratio of the modified amino silicone oil solution to the MDI solution is 10:9;

[0079] 4. Preparation of chain extender component B:

[0080] The chain extender, amino silicone oil and a gradient volatilized composite solvent are mixed to obtain a chain extender B component;

[0081] The chain extender is 4,4'-di-sec-butylaminodiphenylmethane (hereinafter referred to as MDBA); the amino silicone oil in step 4 is bis-aminopropyl polydimethylsiloxane (hereinafter referred to as APT-PDMS);

[0082] The mass ratio of the chain extender to the amino silicone oil is 0.4:1; the mass ratio of the chain extender to the gradient volatilization composite solvent is 0.4:1.

[0083] The method for using the above-mentioned low-pressure spraying high-transparency polyurea-polysiloxane anti-icing / de-icing coating is carried out according to the following steps:

[0084] The semi-prepolymer A component and the chain extender B component of the polyurea-polysiloxane anti-icing / de-icing coating are mixed in a mass ratio of 4:1 to obtain a coating. The coating is sprayed on the surface of an aluminum plate at room temperature and a pressure of 2MPa with a spraying thickness of 220μm. It is initially cured for 6h at room temperature, then cured for 6h at a temperature of 60°C, and finally cured for 10h at a temperature of 80°C to obtain a polyurea-polysiloxane anti-icing / de-icing coating.

[0085] The performance test of the high transparency polyurea-polysiloxane anti-icing / de-icing coating prepared by low-pressure spraying in Example 1 was carried out before and after construction:

[0086] Table 1 Performance test results

[0087]

[0088]

[0089] Table 2 Comparison of ice adhesion strength between polyurea-polysiloxane coating and bare aluminum plate

[0090]

[0091] From the table we can see that:

[0092] 1. The coating has a low viscosity before curing. The coating viscosity is 273cp as measured by a rheometer, and the viscosity is only 417cp after being stored for 3 months. During the spraying process, the coating can be stably atomized and firmly adhered to the surface of the material.

[0093] 2. The A and B components of the coating are stored separately in a closed environment and can be stably stored for more than 3 months, with high storage resistance;

[0094] 3. After the paint is sprayed, it has good self-leveling performance, loses fluidity after about 30 minutes, and is not sticky to the touch after 3 hours. The loss of fluidity can prove that the curing is fast or slow. The prepared paint can be kept sealed when not sprayed and can be stably stored for 2 days, with a long operating time;

[0095] 4. Figure 1 This is a physical picture of the polyurea-polysiloxane anti-icing / de-icing coating prepared in Example 1; a smooth surface is formed after the coating is sprayed.

[0096] 5. Figure 2 This is a contact angle test diagram of the polyurea-polysiloxane anti-icing / de-icing coating prepared in Example 1; as can be seen from the figure, the water droplet contact angle of the material is 100.3°;

[0097] 6. According to the GB / T 528-2009 standard, the mechanical properties of the elastomer obtained by curing the coating are good, the elastic modulus is 498.10kPa, the tensile strength is 97.03kPa, and the elongation at break can reach 100%;

[0098] 7. Under the conditions of -15℃ and 66% relative humidity, the ice delay time and ice adhesion strength test were carried out. The ice delay time was 250s and the ice adhesion strength was 230kPa.

[0099] 8. Wear test according to ASTM D1044-13 standard. After curing, the coating has good wear resistance. After 3000 Taber abrasions, the surface changes little. After 5000 Taber abrasions, it can still maintain good anti-icing / de-icing ability (at a temperature of -15°C and a relative humidity of 66%).

[0100] 9. Figure 3This is a photo of the transparency of the polyurea-polysiloxane anti-icing / de-icing coating prepared in Example 1; the coating obtained by curing the coating has a high transparency, and it can be seen that the coating obtained by spraying is uniform and transparent, and the words behind can be clearly seen through the coating;

[0101] 10. After curing, the coating has very high corrosion resistance. There is no obvious change on the surface after being immersed in acid (1.0 mol / L hydrochloric acid) and alkali solution (1.0 mol / L sodium hydroxide solution) for 72 hours. It can withstand salt spray corrosion for 240 hours (GB / T2423.17-2008) and still maintain good anti-icing / de-icing capabilities (at a temperature of -15°C and a relative humidity of 66%).

[0102] 11. The coating obtained by curing the coating has good ice-repellent properties. Table 2 shows the ice adhesion strength values ​​of the polyurea-polysiloxane anti-icing / deicing coating and the bare aluminum plate. It can be seen that the polyurea-polysiloxane anti-icing / deicing coating has good ice-repellent properties. In addition, after 50 icing / deicing cycles, the coating still has a high anti-icing / deicing ability (at a temperature of -15°C and a relative humidity of 66%).

Claims

1. A method for preparing a high-transparency polyurea-polysiloxane anti-icing / de-icing coating by low-pressure spraying, characterized in that The high transparency polyurea-polysiloxane anti-icing / de-icing coating sprayed at low pressure is composed of a semi-prepolymer component A of the polyurea-polysiloxane anti-icing / de-icing coating and a chain extender component B, and is prepared according to the following steps:

1. Synthesis of modified amino silicone oil: The aminopropyl-terminated polydimethylsiloxane and diethyl maleate are subjected to an N-hetero-Michael addition reaction to obtain a modified amino silicone oil containing a secondary amine group; 2. Preparation of compound solvent: Tetrahydrofuran, xylene and N,N-dimethylformamide are mixed to obtain a gradient volatile composite solvent; 3. Synthesis of semi-prepolymer of component A: The diphenylmethane diisocyanate is reacted with a modified amino silicone oil containing a secondary amine group to obtain a semi-prepolymer component A of a polyurea-polysiloxane anti-icing / de-icing coating; 4. Preparation of chain extender component B: The chain extender, amino silicone oil and a gradient volatilized composite solvent are mixed to obtain a chain extender B component.

2. The method for preparing a high-transparency polyurea-polysiloxane anti-icing / de-icing coating by low-pressure spraying according to claim 1, characterized in that The N-hetero Michael addition reaction described in step 1 is specifically carried out according to the following steps: ① In a nitrogen atmosphere and a rotation speed of 100 rpm to 500 rpm, the aminopropyl-terminated polydimethylsiloxane is heated to 40°C to 60°C, and then diethyl maleate is added dropwise to mix evenly in a nitrogen atmosphere, a rotation speed of 100 rpm to 500 rpm and a temperature of 40°C to 60°C to obtain a mixed solution; ② In a nitrogen atmosphere and a rotation speed of 100rpm to 500rpm, slowly heat the mixed solution to 80°C to 100°C, then reflux with condensed water for 8h to 14h in a nitrogen atmosphere, a rotation speed of 100rpm to 500rpm and a temperature of 80°C to 100°C. After the reflux, stop heating and cooling to obtain a modified amino silicone oil containing a secondary amine group.

3. The method for preparing a high-transparency polyurea-polysiloxane anti-icing / de-icing coating by low-pressure spraying according to claim 2, characterized in that The dropping speed of diethyl maleate described in step 1① is 1 drop / s to 2 drops / s; the mass ratio of aminopropyl-terminated polydimethylsiloxane to diethyl maleate described in step 1① is 1:(0.1 to 0.3); in step 1②, under a nitrogen atmosphere and a rotation speed of 100 rpm to 500 rpm, the mixed solution is slowly heated to 80°C to 100°C at a heating rate of 5°C / min to 15°C / min.

4. The method for preparing a high-transparency polyurea-polysiloxane anti-icing / de-icing coating by low-pressure spraying according to claim 1, characterized in that The mass ratio of tetrahydrofuran to xylene described in step 2 is (1-4):1; the mass ratio of N,N-dimethylformamide to xylene described in step 2 is 1:(1-2).

5. The method for preparing a high-transparency polyurea-polysiloxane anti-icing / de-icing coating by low-pressure spraying according to claim 1, characterized in that The step 3 of reacting the isocyanate with the modified amino silicone oil containing a secondary amine group is specifically carried out according to the following steps: ① Dissolve diphenylmethane diisocyanate in a gradient volatilization compound solvent, and then stir for 10 min to 30 min in a nitrogen atmosphere, a rotation speed of 100 rpm to 500 rpm, and an ice bath at a temperature of 0°C to 5°C to obtain an MDI solution; ② Evenly mix the modified amino silicone oil containing secondary amine groups and the gradient volatilized composite solvent to obtain a modified amino silicone oil solution; ③ Under nitrogen atmosphere and a rotation speed of 100rpm to 500rpm, slowly add the modified amino silicone oil solution to the MDI solution. After the addition is completed, seal the reaction device and stir for 6h to 12h in an ice bath at a rotation speed of 100rpm to 500rpm and a temperature of 0℃ to 5℃. After the reaction is completed, collect the liquid in the reaction device to obtain a clear and transparent colorless solution, i.e., the semi-prepolymer A component of the polyurea-polysiloxane anti-icing / de-icing coating.

6. The method for preparing a high-transparency polyurea-polysiloxane anti-icing / de-icing coating by low-pressure spraying according to claim 5, characterized in that The diphenylmethane diisocyanate described in step 3① is specifically heated to melt at a temperature of 50°C to 70°C; the mass ratio of the diphenylmethane diisocyanate described in step 3① to the gradient volatilization compound solvent is 1:(3~5); the mass ratio of the modified aminosilicone oil containing secondary amine groups described in step 3② to the gradient volatilization compound solvent is 1:(0.1~0.2); the mass ratio of the modified aminosilicone oil solution described in step 3③ to the MDI solution is 1:(0.6~0.9); the dripping speed of the modified aminosilicone oil solution described in step 3③ is 1 drop / s~2 drops / s.

7. The method for preparing a high-transparency polyurea-polysiloxane anti-icing / de-icing coating by low-pressure spraying according to claim 1, characterized in that The chain extender described in step 4 is 4,4'-di-sec-butylaminodiphenylmethane, 4,4'-diaminodiphenylmethane (MDA), p-phenylenediamine, m-phenylenediamine, hexamethylenediamine or diethyltoluenediamine, etc.; the amino silicone oil described in step 4 is bis-aminopropyl polydimethylsiloxane.

8. The method for preparing a low-pressure spray high-transparency polyurea-polysiloxane anti-icing / de-icing coating according to claim 1, characterized in that The mass ratio of the chain extender described in step 4 to the amino silicone oil is (0.2-0.5):1; the mass ratio of the chain extender described in step 4 to the gradient volatilization compound solvent is (0.2-0.5):

1.

9. A method for using a low-pressure spray high-transparency polyurea-polysiloxane anti-icing / de-icing coating prepared as claimed in claim 1, characterized in that It is carried out in the following steps: The semi-prepolymer A component and the chain extender B component of the polyurea-polysiloxane anti-icing / deicing coating are mixed in a mass ratio of (3-5):1 to obtain the coating, the coating is sprayed on the surface of the material and initially cured, and then gradually heated to cure, thereby completing the use of the high-transparency polyurea-polysiloxane anti-icing / deicing coating sprayed at a low pressure.

10. The method for using a low-pressure spray high-transparency polyurea-polysiloxane anti-icing / de-icing coating according to claim 9, characterized in that The spraying is specifically carried out at room temperature and a pressure of 1MPa to 4MPa, and the spraying thickness is 100μm to 300μm; the preliminary curing is specifically carried out at room temperature for 3h to 6h; the gradual temperature increase curing is specifically carried out first at a temperature of 50℃ to 70℃ for 3h to 6h, and then at a temperature of 80℃ to 100℃ for 6h to 10h.

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