Anti-icing coating and preparation method thereof

Abstract

The present invention belongs to the technical field of polymers and functional coatings, and discloses an anti-icing coating and a preparation method thereof. The anti-icing coating comprises the following components in parts by weight: 20-40 parts of hydroxyl acrylic resin; 10-30 parts of terminal hydroxyl fluorinated polysiloxane; 1-3 parts of dispersion promoter; 2-5 parts of hydrophobic migration agent; 1-10 parts of curing agent; 0.5-1 parts of thixotropic agent; 30-70 parts of organic solvent. The anti-icing coating of the present invention adopts reactive hydroxyl acrylic resin and terminal hydroxyl fluorinated polysiloxane as coating matrix, and further adopts specific dispersion promoter and hydrophobic migration agent, while achieving good strength, adhesion and hydrophobic stain resistance, and can be widely used in anti-icing treatment of power facilities, vehicles, and architectural decoration.

Description

Technical Field

[0001] The invention belongs to the technical field of polymers and functional coatings, and specifically relates to an anti-icing coating and a preparation method thereof. Background Art

[0002] The problem of icing on cold surfaces is one of the main problems that affect the normal operation of equipment such as power transmission lines, towers, high-speed rail pantographs and brackets, wind turbine blades, antennas, aircraft, ships and ground transportation vehicles. The use of anti-icing materials can reduce the impact of icing on cold surfaces.

[0003] Anti-icing materials mainly reduce the adhesion of water to the surface and prevent ice formation by introducing a hydrophobic surface with low surface energy. Silicone is widely used in anti-icing materials because of its hydrophobic and low surface energy properties. For example, the Chinese invention patent application document with publication number CN102190935A discloses an anti-icing coating, which uses silicone-modified sodium polyacrylate polymer to improve the anti-icing performance by utilizing the strong hydrophobicity of silicone. However, the anti-icing performance of simply using vinyl silane coupling agent copolymers still needs to be further improved. The Chinese invention patent application document with publication number CN102757708A discloses the use of polyacrylate grafted PDMS copolymers containing POSS to improve the anti-ice and snow ability of the coating. However, the cost of the raw materials used is relatively high.

[0004] Introducing fluorine-containing resins with low surface energy is one of the effective means to improve the anti-icing performance of coatings. For example, in the Chinese invention patent application document with publication number CN111171695 A, it is disclosed that high hydroxy tetrafluoroalkyl (meth) acrylate polymers and fluorinated graphene dispersions are used to improve the anti-ice and snow adhesion effect. In the Chinese invention patent application documents with publication numbers CN106433428A and CN104449317A, it is disclosed that fluororesin emulsions and fluorosilanes are compounded with polyurethane resins to achieve anti-icing effects. However, the above-mentioned fluororesin emulsions and fluorosilanes have poor bonding with polyurethane resins, resulting in poor mechanical properties and anti-icing durability of the coating.

[0005] In addition, existing anti-icing coatings generally have the defect of poor hydrophobic migration. Anti-icing coatings that are exposed to the environment for a long time will have their hydrophobicity and anti-icing performance reduced or even lost due to factors such as dirt, moisture, ultraviolet rays, and low temperature. Summary of the invention

[0006] In view of the shortcomings and deficiencies of the above prior art, the primary purpose of the present invention is to provide an anti-icing coating.

[0007] Another object of the present invention is to provide a method for preparing the above-mentioned anti-icing coating.

[0008] The purpose of the present invention is achieved through the following technical solutions:

[0009] An anti-icing coating comprises the following components in parts by weight:

[0010] 20-40 parts of hydroxy acrylic resin;

[0011] 10-30 parts of terminal hydroxyl fluorinated polysiloxane;

[0012] 1-3 parts of dispersion accelerator;

[0013] 2-5 parts of hydrophobic migration agent;

[0014] 1-10 parts of curing agent;

[0015] Thixotropic agent 0.5-1 part;

[0016] 30-70 parts of organic solvent.

[0017] Furthermore, the hydroxy acrylic resin is a polymer of an unsaturated monomer containing a hydroxyl group (such as hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, etc.) and at least one monomer selected from (meth)acrylic acid, (meth)acrylate, (meth)acrylonitrile, (meth)acrylamide, and styrene. It is a commonly used raw material in the art and can be obtained by purchasing from the market and by conventional free radical copolymerization methods.

[0018] Further, the terminal hydroxyl fluorinated polysiloxane is a silanol-terminated fluorinated polysiloxane obtained by ring-opening copolymerization of a methylcyclosiloxane monomer (such as octamethylcyclotetrasiloxane (D4)) and a fluorinated cyclosiloxane monomer (such as trifluoropropylcyclotrisiloxane (D3F)); or an alcohol hydroxyl-terminated fluorinated polysiloxane obtained by a hydrogen-terminated fluorinated polysiloxane (methylcyclosiloxane monomer, fluorinated cyclosiloxane monomer and hydrogen-terminated agent tetramethyldisiloxane (HMM) obtained by ring-opening copolymerization) and an unsaturated alcohol (such as allyl alcohol) through a hydrosilylation reaction. It is a commonly used raw material in the art and can be purchased from the market and prepared by the above method.

[0019] Furthermore, the dispersant promoter comprises a silane coupling agent and polyether silicone oil, wherein the silane coupling agent comprises 0.5-1.5 parts and the polyether silicone oil comprises 0.5-1.5 parts.

[0020] The present invention adopts a silane coupling agent that can couple with a hydroxyl group and a polyether silicone oil with good surface activity, which can significantly improve the mixed copolymerization curing effect of the hydroxyl acrylic resin and the terminal hydroxyl fluorinated polysiloxane, thereby significantly improving the mechanical properties of the coating. At the same time, the polyether silicone oil has good defoaming performance and can provide a defoaming function.

[0021] Furthermore, the silane coupling agent includes at least one of an epoxy silane coupling agent, an amino silane coupling agent, a vinyl silane coupling agent, an alkyl silane coupling agent, and the like.

[0022] Furthermore, the hydrophobic migration agent is a fluorinated cyclosiloxane; preferably includes at least one of trifluoropropyl cyclotetrasiloxane (D4F) and trifluoropropyl cyclotrisiloxane (D3F), and the structural formulas thereof are as follows:

[0023] D4F, D3F.

[0024] The present invention adopts a specific fluorinated cyclosiloxane as a hydrophobic migration agent, which has the hydrophobic and low surface energy characteristics of polysiloxane and fluorinated compounds. In the coating system of the present invention, it can migrate to the surface of the coating to form a super hydrophobic film in a long-lasting manner, and can migrate its own hydrophobicity to the surface of the dirt, reduce the wetting adsorption of the dirt, improve the self-cleaning effect of the coating, and reduce the adverse effects of the dirt on the hydrophobic durability of the coating.

[0025] Furthermore, the curing agent is a polyisocyanate curing agent. The curing agent of the present invention can simultaneously participate in the cross-linking and curing reaction of the hydroxyl acrylic resin and the terminal hydroxyl fluorinated polysiloxane, thereby improving the compatibility of the components and the mechanical properties of the coating.

[0026] Furthermore, the thixotropic agent is fumed silica.

[0027] Furthermore, the organic solvent includes one or more mixed solvents selected from toluene, xylene, ethyl 3-ethoxypropionate, propylene glycol methyl ether acetate, methyl ethyl ketone, carbon tetrachloride and the like.

[0028] The present invention also provides a method for preparing the above-mentioned anti-icing coating, comprising the following preparation steps: adding a dispersion promoter and a hydrophobic migration agent to an organic solvent and mixing them evenly, then sequentially adding a hydroxyl acrylic resin, a terminal hydroxyl fluorinated polysiloxane and a thixotropic agent and stirring and mixing them evenly, and finally adding a curing agent and mixing them evenly to obtain the anti-icing coating.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] (1) The anti-icing coating of the present invention uses reactive hydroxyl acrylic resin and terminal hydroxyl fluorinated polysiloxane as the coating matrix, wherein the hydroxyl acrylic resin provides good adhesion and the hydroxyl fluorinated polysiloxane provides good hydrophobic anti-icing effect and weather resistance;

[0031] (2) The anti-icing coating of the present invention further uses a dispersing promoter composed of a silane coupling agent and a polyether silicone oil, which can significantly improve the mixed copolymerization curing effect of the hydroxyl acrylic resin and the terminal hydroxyl fluorinated polysiloxane, thereby significantly improving the mechanical properties of the coating;

[0032] (3) The anti-icing coating of the present invention further adopts fluorinated cyclosiloxane as a hydrophobic migration agent, which has the hydrophobic and low surface energy characteristics of both polysiloxane and fluorinated compounds, and has good compatibility with the fluorinated polysiloxane in the coating matrix. It can migrate to the coating surface to form a super hydrophobic film in a long-lasting manner, and can migrate its own hydrophobicity to the surface of contaminants, thereby reducing the wetting and adsorption of contaminants, improving the self-cleaning effect of the coating, and reducing the adverse effects of contaminants on the hydrophobic durability of the coating. DETAILED DESCRIPTION

[0033] The present invention is further described in detail below in conjunction with examples, but the embodiments of the present invention are not limited thereto. Example 1

[0034] An anti-icing coating comprises the following components in parts by weight:

[0035] 30 parts of hydroxy acrylic resin (commercially available, BASF hydroxy acrylic resin);

[0036] 20 parts of terminal hydroxyl fluorinated polysiloxane (prepared by existing literature methods (such as Hong Guoshen et al., Synthesis of terminal hydroxypropyl fluorinated polysiloxane and its modified waterborne polyurethane properties), using D4 and D3F and end-capping agent HMM to obtain hydrogen-terminated fluorinated polysiloxane with a viscosity of 350 mPa·s through ring-opening copolymerization, and then reacting with allyl alcohol through hydrosilylation reaction);

[0037] 1 part of epoxy silane coupling agent (KH-560), 1 part of polyether silicone oil;

[0038] 4 parts of trifluoropropylcyclotetrasiloxane (D4F);

[0039] 6 parts of HDI trimer curing agent;

[0040] 0.8 parts of fumed silica;

[0041] Propylene glycol methyl ether acetate 37.2 parts.

[0042] The preparation method of the anti-icing coating comprises the following preparation steps: adding epoxy silane coupling agent KH-560, polyether silicone oil and hydrophobic migration agent D4F to propylene glycol methyl ether acetate and mixing and dissolving them evenly, then adding hydroxyl acrylic resin, terminal hydroxyl fluorinated polysiloxane and fumed silica in sequence and heating and stirring to mix them evenly, and after cooling to room temperature, adding HDI trimer curing agent and stirring and dissolving them evenly to obtain the anti-icing coating.

[0043] The anti-icing coating obtained in this embodiment has an impact resistance of 67 cm (GB / T 1732-2020) and an adhesion of 8.2 MPa (GB / T 5210-2006). The initial water contact angle is 130°, and the initial oil contact angle is 106°. After 2500 hours of artificial accelerated aging (GB / T14522-2008), the water contact angle is 122°, and the oil contact angle is 101°. The initial stain resistance test (refer to Appendix A of GB / T 9757-2001) shows a result of 0.8, and the stain resistance is 1.0 after 2500 hours of artificial accelerated aging.

[0044] The above results show that the anti-icing coating obtained by the present invention has good mechanical properties, adhesion and long-lasting hydrophobic and stain-resistant properties. Example 2

[0045] An anti-icing coating comprises the following components in parts by weight:

[0046] 20 parts of hydroxy acrylic resin (commercially available, BASF hydroxy acrylic resin);

[0047] 30 parts of terminal hydroxyl fluorinated polysiloxane (self-made, obtained by ring-opening copolymerization of D4 and D3F, with a viscosity of 640 mPa·s);

[0048] 1.5 parts of aminosilane coupling agent (KH-550), 1.5 parts of polyether silicone oil;

[0049] 2 parts of trifluoropropylcyclotetrasiloxane (D4F);

[0050] 10 parts of toluene diisocyanate curing agent;

[0051] 0.5 parts of fumed silica;

[0052] 34.5 parts of xylene.

[0053] The preparation method of the anti-icing coating comprises the following preparation steps: adding aminosilane coupling agent KH-550, polyether silicone oil and hydrophobic migration agent D4F into xylene and mixing and dissolving them uniformly, then adding hydroxyl acrylic resin, terminal hydroxyl fluorinated polysiloxane and fumed silica in sequence and heating and stirring and mixing them uniformly, and after cooling to room temperature, adding toluene diisocyanate curing agent and stirring and dissolving them uniformly to obtain the anti-icing coating.

[0054] The anti-icing coating obtained in this embodiment has an impact resistance of 74 cm, an adhesion of 7.9 MPa, an initial water contact angle of 132°, and an initial oil contact angle of 105°. After 2500 hours of artificial accelerated aging, the water contact angle is 119°, and the oil contact angle is 98°. The initial stain resistance test result is 0.8, and the stain resistance is 1.2 after 2500 hours of artificial accelerated aging.

[0055] The above results show that the anti-icing coating obtained by the present invention has good mechanical properties, adhesion and long-lasting hydrophobic and stain-resistant properties. Example 3

[0056] An anti-icing coating comprises the following components in parts by weight:

[0057] 40 parts of hydroxy acrylic resin (commercially available, BASF hydroxy acrylic resin);

[0058] 10 parts of terminal hydroxyl-containing fluorinated polysiloxane (prepared according to Example 1);

[0059] 0.5 parts of vinyl silane coupling agent (A-151), 0.5 parts of polyether silicone oil;

[0060] 5 parts of trifluoropropylcyclotrisiloxane (D3F);

[0061] 3 parts of toluene diisocyanate curing agent;

[0062] 1 part of fumed silica;

[0063] 40 parts of toluene.

[0064] The preparation method of the anti-icing coating comprises the following preparation steps: adding vinyl silane coupling agent A-151, polyether silicone oil and hydrophobic migration agent D3F into toluene and mixing and dissolving them uniformly, then adding hydroxyl acrylic resin, terminal hydroxyl fluorinated polysiloxane and fumed silica in sequence and heating and stirring and mixing them uniformly, and after cooling to room temperature, adding toluene diisocyanate curing agent and stirring and dissolving them uniformly to obtain the anti-icing coating.

[0065] The anti-icing coating obtained in this embodiment has an impact resistance of 63 cm, an adhesion of 8.7 MPa, an initial water contact angle of 135°, and an initial oil contact angle of 108°. After 2500 hours of artificial accelerated aging, the water contact angle is 120°, and the oil contact angle is 97°. The initial stain resistance test result is 0.8, and the stain resistance is 1.3 after 2500 hours of artificial accelerated aging.

[0066] The above results show that the anti-icing coating obtained by the present invention has good mechanical properties, adhesion and long-lasting hydrophobic and stain-resistant properties. Comparative Example 1

[0067] An anti-icing coating, compared with Example 1, no terminal hydroxyl fluorinated polysiloxane is added, and the amount of hydroxyl acrylic resin added is increased to 50 parts.

[0068] The performance test results of the anti-icing coating obtained in this comparative example showed that the impact resistance was 56 cm; the adhesion was 8.1 MPa; the initial water contact angle was 119°, and the initial oil contact angle was 96°; after 2500 hours of artificial accelerated aging, the water contact angle was 95°, and the oil contact angle was 83°; the initial stain resistance test result was 1.5, and the stain resistance after 2500 hours of artificial accelerated aging was 15.2.

[0069] By comparing the results with those of Example 1, it can be seen that the addition of terminal hydroxyl fluorinated polysiloxane in the present invention can significantly improve the strength and hydrophobic stain resistance of the anti-icing coating obtained. In the absence of terminal hydroxyl fluorinated polysiloxane, the compatibility of the fluorinated cyclosiloxane hydrophobic migration agent with the hydroxy acrylic resin is poor, resulting in a decrease in strength and hydrophobic stain resistance, especially a significant decrease in stain resistance durability. Comparative Example 2

[0070] An anti-icing coating, compared with Example 1, uses an equal amount of methyl-terminated fluorinated polysiloxane (prepared by replacing the end-capping agent HMM in Example 1 with the end-capping agent MM (hexamethyldisiloxane)) to replace the terminal hydroxyl fluorinated polysiloxane.

[0071] The performance test results of the anti-icing coating obtained in this comparative example showed that the impact resistance was 40 cm; the adhesion was 6.2 MPa; the initial water contact angle was 126°, and the initial oil contact angle was 102°; after 2500 hours of artificial accelerated aging, the water contact angle was 112°, and the oil contact angle was 93°; the initial stain resistance test result was 1.4, and the stain resistance was 5.8 after 2500 hours of artificial accelerated aging.

[0072] By comparing the results with those of Example 1, it can be seen that the reactive terminal hydroxyl fluorinated polysiloxane and the hydroxy acrylic resin are compounded in the present invention, which can significantly improve the strength, adhesion and hydrophobic stain resistance of the obtained anti-icing coating compared to the non-reactive methyl-terminated fluorinated polysiloxane. Comparative Example 3

[0073] An anti-icing coating, compared with Example 1, no D4F is added, and the amount of terminal hydroxyl fluorinated polysiloxane added is increased to 24 parts.

[0074] The performance test results of the anti-icing coating obtained in this comparative example showed that the impact resistance was 68 cm; the adhesion was 8.5 MPa; the initial water contact angle was 118°, and the initial oil contact angle was 91°; after 2500 hours of artificial accelerated aging, the water contact angle was 110°, and the oil contact angle was 86°; the initial stain resistance test result was 4.2, and the stain resistance was 4.6 after 2500 hours of artificial accelerated aging.

[0075] By comparing the results with those of Example 1, it can be seen that the present invention can significantly improve the hydrophobic and stain-resistant properties of the anti-icing coating by adding fluorinated cyclosiloxane as a hydrophobic migration agent, with little effect on the strength and adhesion of the coating. Comparative Example 4

[0076] An anti-icing coating, compared with Example 1, does not contain epoxy silane coupling agent KH-560 and polyether silicone oil.

[0077] The performance test results of the anti-icing coating obtained in this comparative example showed that the impact resistance was 52 cm; the adhesion was 7.3 MPa; the initial water contact angle was 125°, and the initial oil contact angle was 99°; after 2500 hours of artificial accelerated aging, the water contact angle was 108°, and the oil contact angle was 94°; the initial stain resistance test result was 1.5, and the stain resistance was 4.6 after 2500 hours of artificial accelerated aging.

[0078] By comparing the results with those of Example 1, it can be seen that the present invention uses silane coupling agent and polyether silicone oil as dispersant promoters for hydroxyl acrylic resin, terminal hydroxyl fluorinated polysiloxane and fluorinated cyclosiloxane, which can promote the compatibility and curing reactivity of each component and significantly improve the strength, adhesion and hydrophobicity and stain resistance of the anti-icing coating.

[0079] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. An anti-icing coating, characterized in that: In parts by weight, it comprises the following components: 20-40 parts of hydroxy acrylic resin; 10-30 parts of terminal hydroxyl fluorinated polysiloxane; 1~3 parts of dispersion accelerator; 2~5 parts of hydrophobic migration agent; 1~10 parts of curing agent; Thixotropic agent 0.5~1 part; 30-70 parts of organic solvent; The dispersion promoter comprises a silane coupling agent and a polyether silicone oil, wherein the silane coupling agent is 0.5 to 1.5 parts and the polyether silicone oil is 0.5 to 1.5 parts; The hydrophobic migration agent is fluorine-containing cyclosiloxane; and the curing agent is a polyisocyanate curing agent.

2. The anti-icing coating according to claim 1, characterized in that: The hydroxy acrylic resin is a polymer of an unsaturated monomer containing a hydroxyl group and at least one monomer selected from the group consisting of (meth)acrylic acid, (meth)acrylate, (meth)acrylonitrile, (meth)acrylamide, and styrene.

3. The anti-icing coating according to claim 1, characterized in that: The terminal hydroxyl fluorinated polysiloxane is a silanol-terminated fluorinated polysiloxane obtained by ring-opening copolymerization of a methylcyclosiloxane monomer and a fluorinated cyclosiloxane monomer; or an alcoholic hydroxyl-terminated fluorinated polysiloxane obtained by a hydrosilylation reaction of a hydrogen-terminated fluorinated polysiloxane and an unsaturated alcohol.

4. The anti-icing coating according to claim 1, characterized in that: The silane coupling agent includes at least one of an epoxy silane coupling agent, an amino silane coupling agent, a vinyl silane coupling agent, and an alkyl silane coupling agent.

5. The anti-icing coating according to claim 1, characterized in that: The fluorine-containing cyclosiloxane is at least one of trifluoropropylcyclotetrasiloxane and trifluoropropylcyclotrisiloxane.

6. The anti-icing coating according to claim 1, characterized in that: The thixotropic agent is fumed silica.

7. The anti-icing coating according to claim 1, characterized in that: The organic solvent is one or more mixed solvents selected from toluene, xylene, ethyl 3-ethoxypropionate, propylene glycol methyl ether acetate, methyl ethyl ketone and carbon tetrachloride.

8. The method for preparing an anti-icing coating according to any one of claims 1 to 7, characterized in that: The method comprises the following preparation steps: The dispersion promoter and the hydrophobic migration agent are added to the organic solvent and mixed evenly, and then the hydroxy acrylic resin, the terminal hydroxy fluorinated polysiloxane and the thixotropic agent are added in sequence and stirred and mixed evenly, and finally the curing agent is added and mixed evenly to obtain the anti-icing coating.