Fluorine-containing polysilazane resin and preparation method thereof, amphiphobic coating composition, amphiphobic coating and preparation method thereof

Abstract

The invention discloses fluorine-containing polysilazane resin and a preparation method thereof, an amphiphobic coating composition, an amphiphobic coating and a preparation method thereof. The structural formula of the fluorine-containing polysilazane resin is # imgabs0 #, m is more than or equal to 0.05 and less than or equal to 0.4, p is more than or equal to 0.1 and less than or equal to 0.5, and n + m + p is equal to 1. The amphiphobic coating prepared from the fluorine-containing polysilazane resin has better amphiphobic effect and higher hardness. The fluorine-containing polysilazane resin is a liquid, can be used as an anti-icing coating, an antifouling coating and other functional coatings, can also be matched with other materials to be applied to the fields of coatings, protection, binders, ceramic precursors, composite materials and the like, and has great development prospects.

Description

Technical Field

[0001] The present invention relates to the technical field of amphiphobic materials, and in particular to a fluorine-containing polysilazane resin and a preparation method thereof, an amphiphobic coating composition, an amphiphobic coating and a preparation method thereof. Background Art

[0002] In nature, many organisms such as lotus leaves, lotus leaves, rice leaves, cicada wings, feathers, water strider legs, etc., when there are pollutants such as dust on the surface, can be carried away by rolling water droplets without leaving any traces. They are natural hydrophobic materials with hydrophobic and self-cleaning effects. Scientific research has found that this hydrophobic surface is mainly composed of materials with low surface energy. Hydrophobic coatings have the advantages of environmental protection and energy saving, and have been widely used in life.

[0003] With the development of science and technology, hydrophobic coatings with a single function can no longer meet the demand, and there is an urgent need to develop multifunctional double-repellent materials (i.e., having both hydrophilicity and lipophilicity). Compared with single hydrophobic materials, double-repellent materials have better self-cleaning functions, are not only hydrophobic but also oleophobic, and also have better performance in terms of anti-icing, anti-bacterial, anti-corrosion, stain resistance, high temperature resistance, and wear resistance. However, on the one hand, there are few organisms of double-repellent materials in nature, and it is impossible to learn from them. On the other hand, due to the low surface tension of oil and other organic matter, the preparation of oleophobic materials is more difficult, which has led to a relatively slow research progress in double-repellent materials. In recent years, rain, snow and freezing disasters have caused varying degrees of losses to power transmission and communication circuits, aviation, navigation, high-speed rail transportation, etc., so it is particularly important to strengthen the research on double-repellent materials.

[0004] Polysilazane is a silicon-nitrogen oligomer that is highly soluble in organic solvents and can be coated on various substrates (metals, plastics, glass, etc.) to provide surface protection, high temperature resistance, and hydrophobicity. In the past few decades, many studies have been conducted on the use of polysilazane to reduce the surface energy of substrates. The Si-H and NH functional groups in polysilazane can be hydrolyzed and converted into a dense polysiloxane structure composed of silicon oxide (Si-O) with high chemical and thermal stability in the presence of moisture and heat treatment, thereby improving the surface protection and high temperature resistance of the coating. In addition, the Si-O group has excellent adhesion by forming a strong physical bond between -OH and the substrate surface, and also has the advantage of being able to form a coating with a thickness of 0.3 to 50 μm. Although the methyl group of the above organic polysilazane exhibits hydrophobicity, it has the problem of being easily wetted by oil due to its lipophilicity. Summary of the invention

[0005] The main purpose of the present invention is to provide a fluorine-containing polysilazane resin and a preparation method thereof, an amphiphobic coating composition, an amphiphobic coating and a preparation method thereof, so as to solve the problem that the organic polysilazane in the prior art is difficult to have both hydrophilicity and lipophilicity.

[0006] In order to achieve the above object, according to one aspect of the present invention, a fluorine-containing polysilazane resin is provided, and the structural formula of the fluorine-containing polysilazane resin is:

[0007]

[0008] Among them, 0.05≤m≤0.4, 0.1≤p≤0.5, and n+m+p=1.

[0009] Further, 0.1≤m≤0.3, and / or 0.2≤p≤0.4.

[0010] According to another aspect of the present invention, a method for preparing the above-mentioned fluorine-containing polysilazane resin is provided, the preparation method comprising: subjecting the reaction materials including dimethyldichlorosilane, heptadecafluorodecyltrifluorosilane and hydrogentrichlorosilane to polymerization reaction in an ammonia atmosphere to obtain the fluorine-containing polysilazane resin.

[0011] Furthermore, the molar ratio of the dimethyldichlorosilane, heptadecafluorodecyltrifluorosilane and hydrogentrichlorosilane is 0.1-0.85:0.05-0.4:0.1-0.5, and preferably the molar ratio of dimethyldichlorosilane, heptadecafluorodecyltrifluorosilane and hydrogentrichlorosilane is 0.5-0.7:0.1-0.3:0.2-0.4.

[0012] Furthermore, the polymerization reaction temperature is -30 to 40°C, and the polymerization reaction time is preferably 3 to 8 hours, preferably 4 to 6 hours.

[0013] According to another aspect of the present invention, there is provided an amphiphobic coating composition, comprising an organosilicon resin, wherein the organosilicon resin is the above-mentioned fluorine-containing polysilazane resin.

[0014] According to another aspect of the present invention, a method for preparing an amphiphobic coating is provided, which is obtained by curing a coating composition, wherein the coating composition is the amphiphobic coating composition described above.

[0015] Furthermore, the curing method is moisture curing, and the preferred moisture curing conditions are: RH of 40-60 and / or temperature of 15-35°C, and / or curing time of 2-4 days, preferably curing for 3 days at RH of 50 and temperature of 20-30°C.

[0016] Furthermore, the curing method is heat curing, and the preferred heat curing conditions are: a temperature of 150 to 250° C., and / or a curing time of 0.5 to 3 hours, preferably curing at a temperature of 180 to 220° C. for 1 to 2 hours.

[0017] According to another aspect of the present invention, there is provided an amphiphobic coating, which is prepared by the above-mentioned preparation method.

[0018] The technical scheme of the present invention is applied, and the fluorine-containing polysilazane resin with the above structure of the present application is a molecular chain with Si-N bond as the main chain, and the side chain contains methyl and NH bonds (active groups), and the silicon atoms and nitrogen atoms in the molecular chain are alternately arranged to form a ring-shaped and linear polymer basic skeleton. The cross-linking density itself can be adjusted by controlling the number of active groups to play a role in curing. At the same time, since the NH bond is used as an active site to make the fluorine-containing polysilazane resin molecule easy to self-polymerize, the fluorine-containing polysilazane resin molecule can be directly used as a double-repellent coating after self-polymerization. The double-repellent effect of the double-repellent coating obtained by the above fluorine-containing polysilazane resin is better and the hardness is higher. And the fluorine-containing polysilazane resin is a liquid, which can be used as a functional coating such as an anti-icing coating and an anti-fouling coating, and can also be applied to coatings, protection, adhesives, ceramic precursors, composite materials and other fields with other materials, with great development prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0020] Figure 1 The figure shows a hydrogen nuclear magnetic spectrum of a fluorine-containing polysilazane resin provided in Example 1 of the present invention. DETAILED DESCRIPTION

[0021] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0022] As analyzed in the background technology of the present application, the organic polysilazanes in the prior art have the problem of being difficult to have both hydrophilicity and lipophilicity. In order to solve this problem, the present application provides a fluorine-containing polysilazane resin and a preparation method thereof, an amphiphobic coating composition, an amphiphobic coating and a preparation method thereof.

[0023] In a typical embodiment of the present application, a fluorine-containing polysilazane resin is provided, and the structural formula of the fluorine-containing polysilazane resin is:

[0024]

[0025] Among them, 0.05≤m≤0.4, 0.1≤p≤0.5, and n+m+p=1.

[0026] The fluorine-containing polysilazane resin with the above structure of the present application is a molecular chain with Si-N bond as the main chain, and a side chain containing methyl and NH bonds (active groups), and the silicon atoms and nitrogen atoms in the molecular chain are alternately arranged to form a ring-shaped and linear polymer basic skeleton. The cross-linking density itself can be adjusted by controlling the number of active groups to play a role in curing. At the same time, since the NH bond is used as an active site to make the fluorine-containing polysilazane resin molecule easy to self-polymerize, the fluorine-containing polysilazane resin molecule can be directly used as a double-dispersible coating after self-polymerization. The double-dispersible effect of the double-dispersible coating obtained by the above fluorine-containing polysilazane resin is better and the hardness is higher. And the fluorine-containing polysilazane resin is a liquid, which can be used as a functional coating such as an anti-icing coating and an anti-fouling coating, and can also be applied to coatings, protection, adhesives, ceramic precursors, composite materials and other fields with other materials, with great development prospects.

[0027] In one embodiment of the present application, 0.1≤m≤0.3, and / or 0.2≤p≤0.4.

[0028] The higher the ratio of m, the better the amphiphobic effect of the amphiphobic coating; the higher the ratio of p, the higher the hardness of the amphiphobic coating. The present invention can control the m value and p value of the synthesized fluorine-containing polysilazane within the above range by controlling the feed ratio, thereby making the amphiphobic effect of the amphiphobic coating better and the hardness higher.

[0029] In another typical embodiment of the present application, a method for preparing the above-mentioned fluorine-containing polysilazane resin is provided, the preparation method comprising: in an ammonia atmosphere, polymerizing reaction raw materials including dimethyldichlorosilane, heptadecafluorodecyltrifluorosilane and hydrogentrichlorosilane to obtain a fluorine-containing polysilazane resin.

[0030] After the partial fluorine substituents in the above monomers are ammonolyzed with ammonia, the products after ammonolysis are polymerized with each other to obtain fluorine-containing polysilazane resin. The fluorine-containing polysilazane resin is used for a double-repellent coating so that the hardness of the double-repellent coating can reach more than 6H after curing. In addition, the synthesized fluorine-containing polysilazane resin is a liquid, which can be used as a functional coating such as an anti-icing coating and an antifouling coating, and can also be applied to coatings, protection, adhesives, ceramic precursors, composite materials and other fields with other materials, and has great development prospects. And the above preparation process is simple, and no precious metal catalysts such as Pt are needed in the preparation process, and the cost is low. The reaction conditions are easy to control, the equipment investment is small, and it is easy to scale production.

[0031] The present invention designs a fluorinated polysilazane amphiphobic coating with antifouling function, low surface energy, excellent substrate adhesion and anti-icing, and the hardness after curing can reach more than 6H. The present invention also provides a preparation method of the fluorinated polysilazane amphiphobic coating, which generally comprises the following steps: adding dimethyldichlorosilane, heptadecafluorodecyltrifluorosilane and hydrogentrichlorosilane in a certain molar ratio, and controlling polymerization at low temperature.

[0032] In one embodiment of the present application, the molar ratio of the above-mentioned dimethyldichlorosilane, heptadecafluorodecyltrifluorosilane and hydrogentrichlorosilane is 0.1-0.85:0.05-0.4:0.1-0.5, and preferably the molar ratio of dimethyldichlorosilane, heptadecafluorodecyltrifluorosilane and hydrogentrichlorosilane is 0.5-0.7:0.1-0.3:0.2-0.4.

[0033] Controlling the feed ratio of the above-mentioned dimethyldichlorosilane, heptadecafluorodecyltrifluorosilane and hydrogentrichlorosilane within the above range helps to fundamentally control the structure of the fluorinated polysilazane resin, thereby maximizing the synergistic effect between the link units by controlling the content of each link unit, thereby obtaining an amphiphobic coating with better amphiphobic effect and higher hardness.

[0034] In one embodiment of the present application, the polymerization reaction temperature is -30 to 40°C, and the polymerization reaction time is preferably 3 to 8 hours, preferably 4 to 6 hours.

[0035] Controlling the temperature and time of the above polymerization reaction helps to improve the efficiency and effect of the polymerization reaction.

[0036] In another typical embodiment of the present application, a dual-phobic coating composition is provided, comprising an organosilicon resin, wherein the organosilicon resin is the above-mentioned fluorine-containing polysilazane resin.

[0037] The amphiphobic coating composition including the fluorine-containing polysilazane resin can be used to prepare an amphiphobic coating with better amphiphobic effect and higher hardness.

[0038] In another typical embodiment of the present application, a method for preparing an amphiphobic coating is provided, which is obtained by curing a coating composition, wherein the coating composition is the amphiphobic coating composition described above.

[0039] By simply curing the amphiphobic coating composition, an amphiphobic coating with better amphiphobic effect and higher hardness can be obtained.

[0040] In one embodiment of the present application, the above-mentioned curing method is moisture curing, and the preferred moisture curing conditions are: RH of 40-60 and / or temperature of 15-35°C, and / or curing time of 2-4d, preferably curing for 3d under the conditions of RH of 50 and temperature of 20-30°C.

[0041] Thanks to the above structure of the fluorine-containing polysilazane resin of the present application, the curing of the fluorine-containing polysilazane resin can be achieved under moisture curing conditions to obtain an amphiphobic coating with excellent comprehensive properties.

[0042] In one embodiment of the present application, the curing method is heat curing, and the preferred heat curing conditions are: temperature of 150-250°C, and / or curing time of 0.5-3h, preferably curing at 180-220°C for 1-2h.

[0043] The fluorine-containing polysilazane resin of the present application can also be cured under the above heating and curing conditions to obtain an amphiphobic coating with excellent comprehensive properties.

[0044] In another typical embodiment of the present application, a amphiphobic coating is provided, and the amphiphobic coating is prepared by the above preparation method.

[0045] The synthesized double-repellent coating of the present invention has good double-repellent effect, excellent substrate adhesion and low surface energy, as well as high hardness, high temperature resistance, corrosion resistance and other comprehensive properties. In addition, the fluorine-containing polysilazane of the present invention is a liquid, which can be used as a functional coating such as an anti-icing coating and an anti-fouling coating, and can also be applied to coatings, protection, adhesives, ceramic precursors, composite materials and other fields in combination with other materials, and has great development prospects.

[0046] The beneficial effects of the present application will be further illustrated below in conjunction with embodiments.

[0047] Example 1

[0048] (1) monomers dimethyldichlorosilane, heptadecafluorodecyltrifluorosilane and hydrogentrichlorosilane are added to a reaction kettle in a certain molar ratio, the raw materials are mixed evenly and refrigerated, and the polymerization temperature is controlled at -30°C; wherein the molar ratio of the monomers dimethyldichlorosilane (n), heptadecafluorodecyltrifluorosilane (m) and hydrogentrichlorosilane (p) is 0.5:0.3:0.2.

[0049] (2) Slowly introduce ammonia into the reactor, and the polymerization reaction time is 5 hours;

[0050] (3) Stop introducing ammonia gas;

[0051] (4) Filter out debris;

[0052] (5) After rotary evaporation, a liquid product, i.e., a fluorine-containing polysilazane resin, is obtained, and its NMR spectrum is as follows: Figure 1 shown.

[0053] Example 2

[0054] The difference from Example 1 is that the feeding molar ratio of n:m:p is 0.5:0.1:0.4, and fluorine-containing polysilazane is finally obtained.

[0055] Example 3

[0056] The difference from Example 1 is that the feeding molar ratio of n:m:p is 0.5:0.2:0.3, and fluorine-containing polysilazane is finally obtained.

[0057] Example 4

[0058] The difference from Example 1 is that the feeding molar ratio of n:m:p is 0.85:0.05:0.1, and fluorine-containing polysilazane is finally obtained.

[0059] Example 5

[0060] The difference from Example 1 is that the feeding molar ratio of n:m:p is 0.1:0.4:0.5, and fluorine-containing polysilazane is finally obtained.

[0061] Example 6

[0062] The difference from Example 1 is that the polymerization reaction temperature is controlled at 10° C., and fluorine-containing polysilazane is finally obtained.

[0063] Example 7

[0064] The difference from Example 1 is that the polymerization reaction temperature is controlled at 40° C., and fluorine-containing polysilazane is finally obtained.

[0065] Example 8

[0066] The difference from Example 1 is that the polymerization reaction temperature is controlled at 45° C., and fluorine-containing polysilazane is finally obtained.

[0067] Example 9

[0068] The difference from Example 1 is that the polymerization reaction time is controlled to be 4 hours, and fluorine-containing polysilazane is finally obtained.

[0069] Example 10

[0070] The difference from Example 1 is that the polymerization reaction time is controlled to be 6 hours, and fluorine-containing polysilazane is finally obtained.

[0071] Embodiment 11

[0072] The difference from Example 1 is that the polymerization reaction time is controlled to be 3 hours, and fluorine-containing polysilazane is finally obtained.

[0073] Example 12

[0074] The difference from Example 1 is that the polymerization reaction time is controlled to be 8 hours, and fluorine-containing polysilazane is finally obtained.

[0075] The yields of the fluorine-containing polysilazane resins obtained in the above Examples 1 to 12 are listed in Table 1.

[0076] Coating Examples 1 to 12

[0077] The aluminum plate was first ultrasonically cleaned with ethanol, and then the cleaned aluminum plate was immersed in 2.5M HCl and etched at room temperature for 10 minutes, and then the aluminum plate was rinsed with deionized water and dried. The fluorinated polysilazanes synthesized in Examples 1 to 12 were respectively dissolved in mineral spirits to form 10wt% solutions, and were respectively dip-coated on the aluminum plate substrate, and respectively cured by moisture, and the curing conditions were: 50RH%, 30°C, and cured for 3 days.

[0078] Coating Example 13

[0079] The difference between coating example 13 and coating example 1 is that the curing conditions are: 60RH% and 35°C for 2 days.

[0080] Coating Example 14

[0081] The difference between coating example 14 and coating example 1 is that coating example 14 is cured by heating, and the curing conditions are: 220° C. and curing for 2 hours.

[0082] Coating Example 15

[0083] The difference between coating example 15 and coating example 14 is that coating example 15 is cured by heating, and the curing conditions are: 150° C. and curing for 3 hours.

[0084] Coating Comparative Example 1

[0085] The difference between coating comparative example 1 and coating example 1 is that m=p=0.5, and fluorine-containing polysilazane is finally obtained.

[0086] After testing, the hardness of the amphiphobic coatings of coating examples 1 to 15 and coating comparative example 1, the contact angle of the amphiphobic coatings with water, and the contact angle of the amphiphobic coatings with n-hexane are shown in Table 2.

[0087] Table 1

[0088]

[0089]

[0090] Table 2

[0091]

[0092] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects:

[0093] The fluorine-containing polysilazane resin with the above structure of the present application is a molecular chain with Si-N bond as the main chain, and a side chain containing methyl and NH bonds (active groups), and the silicon atoms and nitrogen atoms in the molecular chain are alternately arranged to form a ring-shaped and linear polymer basic skeleton. The cross-linking density itself can be adjusted by controlling the number of active groups to play a role in curing. At the same time, since the NH bond is used as an active site to make the fluorine-containing polysilazane resin molecule easy to self-polymerize, the fluorine-containing polysilazane resin molecule can be directly used as a double-dispersible coating after self-polymerization. The double-dispersible effect of the double-dispersible coating obtained by the above fluorine-containing polysilazane resin is better and the hardness is higher. And the fluorine-containing polysilazane resin is a liquid, which can be used as a functional coating such as an anti-icing coating and an anti-fouling coating, and can also be applied to coatings, protection, adhesives, ceramic precursors, composite materials and other fields with other materials, with great development prospects.

[0094] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A fluorine-containing polysilazane resin, characterized in that: The structural formula of the fluorine-containing polysilazane resin is: Among them, 0.05≤m≤0.4, 0.1≤p≤0.5, and n+m+p=1.

2. The fluorine-containing polysilazane resin according to claim 1, characterized in that 0.1≤m≤0.3, and / or 0.2≤p≤0.

4.

3. A method for preparing the fluorine-containing polysilazane resin according to claim 1 or 2, characterized in that: The preparation method comprises: In an ammonia atmosphere, the reaction raw materials including dimethyldichlorosilane, heptadecafluorodecyltrifluorosilane and hydrogentrichlorosilane are polymerized to obtain the fluorine-containing polysilazane resin.

4. The preparation method according to claim 3, characterized in that: The molar ratio of the dimethyldichlorosilane, the heptadecafluorodecyltrifluorosilane and the hydrogentrichlorosilane is 0.1-0.85:0.05-0.4:0.1-0.5, and preferably the molar ratio of the dimethyldichlorosilane, the heptadecafluorodecyltrifluorosilane and the hydrogentrichlorosilane is 0.5-0.7:0.1-0.3:0.2-0.

4.

5. The preparation method according to claim 3 or 4, characterized in that: The polymerization reaction temperature is -30 to 40°C, and the polymerization reaction time is preferably 3 to 8 hours, preferably 4 to 6 hours.

6. A dual-phobic coating composition comprising a silicone resin, characterized in that: The organic silicone resin is the fluorine-containing polysilazane resin according to claim 1 or 2.

7. A method for preparing an amphiphobic coating, obtained by curing a coating composition, characterized in that: The coating composition is the amphiphobic coating composition according to claim 6.

8. The preparation method according to claim 7, characterized in that: The curing method is moisture curing, and the moisture curing conditions are preferably: RH of 40-60 and / or temperature of 15-35°C, and / or curing time of 2-4 days, preferably curing for 3 days under the conditions of RH of 50 and temperature of 20-30°C.

9. The preparation method according to claim 8, characterized in that: The curing method is heat curing, and the heat curing conditions are preferably: a temperature of 150 to 250° C., and / or a curing time of 0.5 to 3 hours, preferably curing at a temperature of 180 to 220° C. for 1 to 2 hours.

10. An amphiphobic coating, characterized in that: The amphiphobic coating is prepared by the preparation method described in any one of claims 7 to 9.

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