Organic silicon hydrophobic and ice-repellent coating and preparation method thereof

Abstract

The invention belongs to the technical field of functional coatings, and particularly relates to an organosilicone hydrophobic and hydrophobic coating and a preparation method thereof. The coating is prepared from the following raw materials: hydrogen-terminated polydimethylsiloxane, vinyl MQ resin, silane coupling agent modified nano silicon dioxide, a catalyst and an organic solvent. The invention also provides a preparation method of the coating and a hydrophobic and hydrophobic coating prepared from the coating. The obtained coating has excellent hydrophobicity and ice hydrophobicity, the problem that the surface of the coating is sticky is effectively solved, and the coating can be widely applied to the fields needing ice prevention and water prevention such as aviation, electric power and traffic. The preparation process is simple, raw materials are easy to obtain, and the method has good industrial application prospects.

Description

An organosilicon hydrophobic and ice-repellent coating and its preparation method Technical Field

[0001] This invention belongs to the field of functional coatings technology, specifically relating to an organosilicon hydrophobic and ice-repellent coating and its preparation method. Background Technology

[0002] In aerospace, power communications, and transportation industries, surface icing can lead to equipment damage, reduced operating efficiency, and even safety accidents. Traditional anti-icing methods, such as heating and mechanical de-icing, suffer from high energy consumption and low efficiency. In recent years, hydrophobic and anti-icing coatings have received widespread attention due to their advantages such as passive anti-icing, low energy consumption, and ease of application.

[0003] In existing technologies, hydrophobic coatings are often prepared by combining low surface energy materials with micro / nano structures. However, existing coatings still suffer from insufficient ice-repellent properties, surface stickiness, and poor durability in practical applications. Therefore, developing a coating that combines excellent hydrophobicity and ice-repellency, and whose surface does not adhere to ice, has significant application value. Summary of the Invention

[0004] The present invention aims to provide an organosilicon hydrophobic and ice-repellent coating, which has the advantages of high hydrophobic angle, low ice adhesion strength and non-stick surface, thus solving the problems of sticky coating surface and poor ice-repellent performance in the prior art.

[0005] This invention is achieved through the following technical solution:

[0006] In a first aspect, the present invention provides an organosilicon hydrophobic and icy coating, which is prepared from raw materials comprising the following components: hydrogen-terminated polydimethylsiloxane (PDMS), vinyl MQ resin, silane coupling agent modified nano-silica, catalyst, and organic solvent.

[0007] Furthermore, the mass ratio of the hydrogen-capped polydimethylsiloxane to the vinyl MQ resin is 1:0.75 to 1:1, preferably 1:0.84 to 1:0.92.

[0008] Furthermore, the mass ratio of the hydrogen-terminated polydimethylsiloxane to the silane coupling agent-modified nano-silica is 1:0.332 to 1:0.4, preferably 1:0.366.

[0009] Furthermore, the number-average molecular weight Mn of the hydrogen-terminated polydimethylsiloxane is 7000.

[0010] As used herein, hydrogen-terminated polydimethylsiloxane is a commonly used organosilicon intermediate in the art, which is commercially available or prepared by conventional techniques well known in the art, such as by a ring-opening equilibrium reaction of a cyclosiloxane with a capping agent (such as tetramethyldisiloxane) in the presence of an acidic catalyst.

[0011] Furthermore, the vinyl MQ resin is a CF90-7 or CF-9072 type vinyl MQ resin powder.

[0012] As used herein, vinyl MQ resin is a fundamental raw material in the field of organosilicon, and its structure and synthesis methods (such as the sodium silicate method and the silane co-hydrolysis polycondensation method) are conventional techniques in the field and are readily available commercially.

[0013] Furthermore, the silane coupling agent is KH570.

[0014] Furthermore, the catalyst is a platinum catalyst.

[0015] Furthermore, the platinum catalyst is a PT-5000 type platinum catalyst (Pt concentration: 5000ppm).

[0016] Furthermore, the organic solvent is tetrahydrofuran.

[0017] In a second aspect, the present invention provides a method for preparing an organosilicon hydrophobic and ice-repellent coating as described herein, comprising the following steps:

[0018] (1) Add hydrogen-terminated polydimethylsiloxane and vinyl MQ resin to an organic solvent and mix them evenly to obtain premix A;

[0019] (2) The nano-silica modified with silane coupling agent was dispersed in an organic solvent to obtain dispersion B;

[0020] (3) Add dispersion B to premix A and mix well to obtain mixture C;

[0021] (4) Add a catalyst to the mixture C to react and obtain an organosilicon hydrophobic and ice-repellent coating.

[0022] In a third aspect, the present invention provides a hydrophobic and icing-repellent coating, which is obtained by curing an organosilicon hydrophobic and icing-repellent coating as described herein onto a substrate surface.

[0023] Furthermore, the curing is carried out at 70-100°C for 1-3 hours.

[0024] Beneficial effects of the present invention

[0025] Compared with the prior art, the present invention has the following advantages:

[0026] High hydrophobicity: By adjusting the ratio of MQ resin to PDMS and introducing hydrophobic nanofillers, a micro-nano structure is formed on the coating surface, and the water contact angle can reach more than 140°.

[0027] Excellent ice-repellent properties: The introduction of a specific amount of KH570 modified nano silica not only solves the problem of film surface stickiness, but also significantly reduces ice adhesion strength (as low as 40-60 kPa). Attached Figure Description

[0028] Figure 1 shows the hydrophobic properties of organosilicon coatings prepared with different ratios of hydrogen silane-terminated PDMS and MQ.

[0029] Figure 2 shows the hydrophobic properties of the organosilicon hydrophobic and icy coating prepared in Example 9.

[0030] Figure 3 shows the hydrophobic properties of the organosilicon hydrophobic and icy coating prepared in Example 12.

[0031] Figure 4 shows the ice-repellent properties of the organosilicon hydrophobic and ice-repellent coatings prepared in Examples 11-13.

[0032] Figure 5 shows the stability of the silicone coating prepared using PDMS with Mn of 2000 compared to that prepared using PDMS with Mn of 7000. Detailed Implementation

[0033] The present invention will be further illustrated below with reference to specific embodiments, but the embodiments do not limit the present invention in any way. Unless otherwise specified, the reagents, methods, and equipment used in the present invention are conventional reagents, methods, and equipment in this technical field.

[0034] Example 1:

[0035] This embodiment provides an organosilicon hydrophobic coating, which is prepared from the following components:

[0036] Hydrogen-terminated polydimethylsiloxane (PDMS, Mn=7000): 0.5g

[0037] Vinyl MQ resin (CF90-7, Mn=2860, Mw=4029, PDI=1.41, hydroxyl content 1.32wt%, vinyl content 2.5wt%): 0.125g

[0038] Platinum catalyst (PT-5000): 1 drop

[0039] Tetrahydrofuran (THF): 2 mL.

[0040] Coating preparation method: Weigh PDMS and MQ resin and place them in a glass bottle. Add 2 ml of tetrahydrofuran and stir evenly. Add 1 drop of PT catalyst and stir for 2 h to obtain the coating.

[0041] Coating preparation: The coating is evenly applied to the iron plate and cured in an 80℃ oven for 2 hours to obtain the coating.

[0042] Example 2

[0043] Same as in Example 1, except that the amount of vinyl MQ resin added is 0.25g.

[0044] Example 3

[0045] Same as in Example 1, except that the amount of vinyl MQ resin added is 0.375g.

[0046] Example 4

[0047] Same as in Example 1, except that the amount of vinyl MQ resin added is 0.42g.

[0048] Example 5

[0049] Same as in Example 1, except that the amount of vinyl MQ resin added was 0.46g.

[0050] Example 6

[0051] Same as in Example 1, except that the amount of vinyl MQ resin added is 0.5g.

[0052] Example 7

[0053] Same as in Example 1, except that the amount of vinyl MQ resin added is 0.75g.

[0054] Example 8

[0055] Same as in Example 1, except that the amount of vinyl MQ resin added is 1.0g.

[0056] The hydrophobic properties of the coatings prepared in Examples 1-8 were tested, and the results are shown in Figure 1. It can be seen that when the mass ratio of hydrogen-terminated polydimethylsiloxane to vinyl MQ resin is 1:0.75 to 1:1, the coating has good hydrophobic properties.

[0057] Example 9

[0058] This embodiment provides an organosilicon hydrophobic and ice-repellent coating, which is prepared from the following components:

[0059] Hydrogen-terminated polydimethylsiloxane (PDMS, Mn=7000): 0.5g

[0060] Vinyl MQ resin (CF90-7): 0.42g

[0061] Platinum catalyst (PT-5000): 2 drops

[0062] Hydrophobic filler KH570 modified nano-silica: 0.1g

[0063] Tetrahydrofuran (THF): 4 mL.

[0064] Coating preparation method: Weigh PDMS and MQ resin and place them in a glass bottle. Add 2 ml of tetrahydrofuran and stir evenly to obtain a premix. Then weigh the hydrophobic filler in another glass bottle and add 2 ml of tetrahydrofuran. Stir evenly to obtain a dispersion. Finally, transfer the silica dispersion to the PDMS premix and stir for 10 min to mix evenly. Add 2 drops of PT catalyst and stir for 2 h to obtain the coating.

[0065] Coating preparation: The coating is evenly applied to the iron plate and cured in an 80℃ oven for 2 hours to obtain the coating.

[0066] The hydrophobic properties of the coating prepared in Example 9 were tested, and the results are shown in Figure 2. It can be seen that the water contact angle of the coating is 154.3°, which shows excellent hydrophobic properties. However, the coating surface is sticky when tested by the finger touch method, indicating that ice will stick to it and is difficult to remove, indicating insufficient ice-repellent properties.

[0067] Example 10

[0068] Similar to Example 9, except that the amount of KH570 modified nano-silica added was 0.15g. The coating prepared in Example 10 was found to be sticky and lacked sufficient ice-repellent properties according to the finger-touch test.

[0069] Example 11

[0070] Same as Example 9, except that the amount of KH570 modified nano-silica added was 0.166 g. The coating prepared in Example 11 was non-sticky, exhibited good ice-repellent properties, and had a water contact angle of 135°, as tested by the finger touch method.

[0071] Example 12

[0072] Same as Example 9, except that the amount of KH570 modified nano-silica added was 0.183g. The coating prepared in Example 12 was non-sticky and exhibited good ice-repellent properties, with a water contact angle of 142° (as shown in Figure 3), as tested by the finger touch method.

[0073] Example 13

[0074] Same as Example 9, except that the amount of KH570 modified nano-silica added was 0.2g. The coating prepared in Example 11 was non-sticky, exhibited good ice-repellent properties, and had a water contact angle of 137°, as tested by the finger touch method.

[0075] In addition, ice-repellency tests were conducted on the coatings prepared in Examples 11-13. The test method was as follows: the ice platform temperature was controlled at approximately -10°C, and ice blocks were placed on the film surface for about 5 minutes to ensure adhesion. The ice blocks were then pushed at a uniform speed until they moved. The ice adhesion strength was calculated by dividing the pushing force by the contact area between the ice block and the coating. The test results are shown in Figure 4. It can be seen that the ice adhesion strength of the coatings prepared in Examples 11-13 was less than 100 kPa, indicating good ice-repellency properties. Among them, the coating prepared in Example 12 exhibited the best ice-repellency performance.

[0076] Comparative Example 1

[0077] Similar to Example 12, except that PDMS with Mn of 2000 was used instead of PDMS with Mn of 7000. The coating prepared with PDMS with Mn of 2000 has poor hydrophobic properties, and as can be seen from Figure 5, the coating has poor stability and is easily damaged during curing after the addition of hydrophobic filler.

[0078] Comparative Example 2

[0079] To investigate the stability of coatings using other crosslinking methods, high molecular weight vinyl PDMS and vinyl MQ resins were selected as monomers, and coatings were prepared using trimethylolpropane tris(3-mercaptopropionic acid) ester (TMTP) and POSS-SH as crosslinking agents, respectively. The results showed that the stability of the coatings prepared by vinyl and mercapto photocuring was lower than that of the coatings prepared by hydrosilylation in this invention.

[0080] Comparative Example 3

[0081] Similar to Example 9, except that the KH570 modified nano-silica was replaced with hydrophobic nano-silica. Testing showed that the water contact angle of the coating prepared in Comparative Example 3 was 130°, a significant decrease in hydrophobicity compared to Example 9.

[0082] It should be noted that while the preferred embodiments of the present invention are given in the specification and accompanying drawings, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are not intended to impose additional limitations on the content of the present invention; their purpose is to provide a more thorough and comprehensive understanding of the disclosure of the present invention. Furthermore, the above-described technical features can be combined with each other to form various embodiments not listed above, all of which are considered to be within the scope of the present invention specification. Moreover, those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. An organosilicon hydrophobic and ice-repellent coating, characterized in that, It is prepared from raw materials including the following components: hydrogen-terminated polydimethylsiloxane, vinyl MQ resin, silane coupling agent modified nano-silica, catalyst, and organic solvent.

2. The organosilicon hydrophobic and ice-repellent coating according to claim 1, characterized in that, The mass ratio of the hydrogen-terminated polydimethylsiloxane to the vinyl MQ resin is 1:0.75 to 1:1, preferably 1:0.84 to 1:0.

92.

3. The organosilicon hydrophobic and ice-repellent coating according to claim 1, characterized in that, The mass ratio of the hydrogen-terminated polydimethylsiloxane to the silane coupling agent-modified nano-silica is 1:0.332 to 1:0.4, preferably 1:0.

366.

4. The organosilicon hydrophobic and ice-repellent coating according to claim 1, characterized in that, The number-average molecular weight (Mn) of the hydrogen-terminated polydimethylsiloxane is 7000.

5. The organosilicon hydrophobic and ice-repellent coating according to claim 1, characterized in that, The silane coupling agent is KH570.

6. The organosilicon hydrophobic and ice-repellent coating according to claim 1, characterized in that, The catalyst is a platinum catalyst.

7. The organosilicon hydrophobic and ice-repellent coating according to claim 1, characterized in that, The organic solvent is tetrahydrofuran.

8. A method for preparing an organosilicon hydrophobic and ice-repellent coating as described in any one of claims 1-7, characterized in that, The process includes the following steps: (1) adding hydrogen-terminated polydimethylsiloxane and vinyl MQ resin to an organic solvent and mixing them evenly to obtain a premix A; (2) dispersing silane coupling agent modified nano-silica into an organic solvent to obtain a dispersion B; (3) adding dispersion B to premix A and mixing them evenly to obtain a mixture C; (4) adding a catalyst to mixture C to react and obtain an organosilicon hydrophobic and icy coating.

9. A hydrophobic and ice-repellent coating, characterized in that, The coating is obtained by curing an organosilicon hydrophobic and icy coating on a substrate surface according to any one of claims 1-7.

10. The hydrophobic and ice-repellent coating according to claim 9, characterized in that, The curing process is carried out at 70-100°C for 1-3 hours.

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