A siloxane-terminated fluorine-containing hyperbranched polyurethane and a preparation method thereof, and a photocurable coating

Abstract

The invention discloses a fluorine-containing hyperbranched polyurethane terminated with siloxane and a preparation method thereof, and a photocurable coating. First, a fluorine-containing hyperbranched polyurethane containing a large amount of hydroxyl groups is prepared, and then the polyurethane is reacted with siloxane to obtain a fluorine-containing hyperbranched polyurethane terminated with siloxane. The fluorine-containing hyperbranched polyurethane terminated with siloxane prepared by the invention has a hyperbranched structure, is not easy to be entangled between molecules, has a low viscosity, and has excellent fluidity and film-forming properties. In addition, the presence of perfluoroalkyl and a siloxane structure for end-capping endows the polymer with excellent hydrophobic antifouling, friction resistance, chemical corrosion resistance, aging resistance and other characteristics, and thus has a wide range of application prospects.

Description

Technical Field

[0001] The invention relates to a siloxane-terminated fluorine-containing hyperbranched polyurethane and a preparation method thereof, and also relates to a photocurable coating, belonging to the field of coatings. Background Art

[0002] With the advent of the intelligent era, smart digital products such as mobile phones, computers, and tablets have brought great convenience to our daily lives and work. However, the only drawback is that fingerprints left on touch panels and displays, as well as damage caused by scratches or friction from metal products such as keys, have greatly affected the image quality seen on touch panels and displays and the appearance of the device itself. However, the above problems can be solved by attaching film coatings on touch panels and displays.

[0003] Currently, among low surface energy materials, perfluoroalkyl compounds and polymers are ideal candidates for improving stain resistance and hydrophobic and oleophobic (i.e., amphiphilic) properties because of their low surface tension, low wettability, and low stain adhesion. In addition, by combining SiO2 particles with fluorinated low surface energy materials by physical mixing or chemical bonding, excellent anti-fingerprint and stain resistance properties can be exhibited. Chinese invention patent application CN116925624A, Chinese invention patent application CN113354791A, and Chinese invention patent application CN103897572 A are all based on this idea. However, the nanoparticles contained in the system can easily fall off the surface of the film coating. In addition, cracking, low transmittance, and poor friction durability remain relevant challenges for such film coatings in actual use. Chemical bonding or firmly combining nanoparticles with perfluoropolymers or perfluorosilsesquioxanes can solve the above problems and provide better properties (such as rigidity and transparency) for the manufactured film coating.

[0004] Polyurethane (PU) is a common polymer composed of soft segments and hard segments. It can be used to adjust the formula to obtain high toughness, high hardness, and high elasticity coatings in a wide range to meet various needs. However, due to the presence of urethane in its structure, the viscosity of polyurethane is greater than that of other polymers with the same molecular weight. Therefore, reducing the viscosity of polyurethane by modification is expected to become a solution for a new type of membrane material. Summary of the invention

[0005] In view of the defects existing in the prior art, the first object of the present invention is to provide a fluorine-containing hyperbranched polyurethane terminated with a siloxane. The polyurethane has a hyperbranched structure and is not easy to be entangled between molecules. It not only has low viscosity and excellent film-forming properties, but also, due to the presence of perfluoroalkyl groups and the siloxane structure used for end-capping, the hyperbranched structure synergistically gives the polymer excellent hydrophobic anti-fouling, friction resistance, chemical corrosion resistance and aging resistance during application.

[0006] The second object of the present invention is to provide a method for preparing a fluorine-containing hyperbranched polyurethane terminated with a siloxane group, which has the advantages of being simple and easy to operate, having a high reaction rate and mild conditions, and is conducive to large-scale production.

[0007] The third object of the present invention is to provide a photocurable coating, which comprises a fluorine-containing hyperbranched polyurethane terminated with a siloxane group, and the polyurethane and other components act synergistically to give the coating good adhesion, better hydrophobicity and wear resistance.

[0008] In order to achieve the above technical objectives, the present invention provides a siloxane-terminated fluorine-containing hyperbranched polyurethane having a structure as shown in Formula I:

[0009]

[0010] Formula I;

[0011] Wherein, Rf is a perfluoroalkyl group having a structure as shown in Formula II:

[0012]

[0013] Formula II;

[0014] n is an integer from 1 to 20;

[0015] Wherein, R1 is the main structure of diisocyanate, R1 is , or ;

[0016] in, It is a polymeric main structure of diisocyanate and diethanolamine, consisting of m repeated structures of formula III;

[0017]

[0018] Formula III;

[0019] Wherein, m is an integer from 1 to 3000, R1 is , or ;

[0020] Wherein, R2 is a siloxane group, R2 is , , , , or .

[0021] In the present invention, polyurethane is by building hyperbranched structure, on the one hand, it is difficult for molecules to be entangled, and the viscosity of polymer is significantly reduced, and polyurethane is avoided in the prior art due to the presence of carbamate, so that its viscosity is compared with the problem that the viscosity of other polymers of the same molecular weight is large, thereby enhancing its film-forming properties. On the other hand, the existence of hyperbranched structure gives polyurethane a large amount of terminal hydroxyl structures, and it is necessary to carry out end-capping treatment with more siloxanes, thereby generating abundant silicon oxygen bonds, and these silicon oxygen bonds play a bridge role in polyurethane curing process, greatly enhancing the bonding force between material and substrate, thereby greatly improving the wear resistance of coating and the stability of polymer overall structure. At the same time, because silicon oxygen bonds are located at molecular chain ends, they are more likely to be closely combined with substrates, and fluorine-containing groups are urged toward one side of air, and the enrichment of fluorine-containing groups on coating surface is realized, and the hydrophobic antifouling effect and weather resistance of coating are significantly strengthened.

[0022] The present invention also provides a method for preparing a fluorine-containing hyperbranched polyurethane terminated with siloxane, which comprises the following steps: subjecting a perfluoroalkyl acetate compound and diethanolamine to a substitution reaction I to obtain an intermediate 1; subjecting the intermediate 1 to an esterification reaction with maleic anhydride to obtain an intermediate 2; subjecting the intermediate 2 to an amidation reaction I with diethanolamine to obtain an intermediate 3; subjecting the intermediate 3 to an amidation reaction III with a monomer AB2 under the catalysis of dibutyltin dilaurate to obtain an intermediate 4; subjecting the intermediate 4 to a polymerization reaction with the monomer AB2 to obtain a fluorine-containing hyperbranched polyurethane; subjecting the fluorine-containing hyperbranched polyurethane to a substitution reaction II with siloxane to obtain a polyurethane; subjecting the monomer AB2 to an amidation reaction II with a diisocyanate and diethanolamine to obtain a polyurethane.

[0023] Among them, intermediate 1 has a structure as shown in Formula IV:

[0024]

[0025] Formula IV;

[0026] Intermediate 2 has a structure of Formula V:

[0027]

[0028] Formula V;

[0029] Intermediate 3 has the structure of Formula VI:

[0030]

[0031] Formula VI;

[0032] Intermediate 4 has the structure of Formula VII:

[0033]

[0034] Formula VII;

[0035] The fluorinated hyperbranched polyurethane has a structure such as Formula VIII:

[0036]

[0037] Formula VIII;

[0038] Monomer AB2 has the structure of Formula IX:

[0039]

[0040] Formula IX.

[0041] The key technology of the present invention is to utilize the more active amine group in diethanolamine to undergo substitution reaction I with the ester group of the perfluoroalkyl acetate compound, thereby generating an intermediate 1; the intermediate 1 contains two hydroxyl groups, which are easily esterified with anhydride to generate an intermediate 2 containing two molecules of carboxylic acid structure; then, the intermediate 2 further reacts with the active amine group in diethanolamine to generate an intermediate 3 having four molecules of hydroxyl group; in addition, a monomer AB2 having two molecules of hydroxyl structure is obtained by an amidation reaction II between diisocyanate and diethanolamine; thereafter, an excess of the monomer AB2 is continuously polymerized with the intermediate 3 to generate a fluorine-containing hyperbranched polyurethane; finally, the hydroxyl group in the fluorine-containing hyperbranched polyurethane is substituted with siloxane to generate a fluorine-containing hyperbranched polyurethane terminated by siloxane.

[0042] As a preferred embodiment, the molar ratio of the perfluoroalkyl acetate compound to diethanolamine in the substitution reaction I is 1:(1-1.2); more preferably, the molar ratio of the perfluoroalkyl acetate compound to diethanolamine is 1:1.2.

[0043] As a preferred embodiment, the molar ratio of the intermediate 1 to maleic anhydride in the esterification reaction is 1:(2-2.4); more preferably, the molar ratio of the intermediate 1 to maleic anhydride is 1:2.2.

[0044] As a preferred embodiment, the molar ratio of the intermediate 2 to diethanolamine in the amidation reaction I is 1:(2-2.4); more preferably, the molar ratio of the intermediate 2 to diethanolamine is 1:2.4.

[0045] As a preferred embodiment, the molar ratio of diisocyanate to diethanolamine in the amidation reaction II is 1:(1-1.2); more preferably, the molar ratio of diisocyanate to diethanolamine is 1:1.1.

[0046] As a preferred embodiment, the molar ratio of the intermediate 3 to the monomer AB2 in the amidation reaction III is 1:(4-4.8); more preferably, the molar ratio of the intermediate 3 to the monomer AB2 is 1:4.4.

[0047] As a preferred embodiment, the molar ratio of the intermediate 4 to the monomer AB2 in the polymerization reaction is 1:(8m~9.6m), wherein m=an integer of 1~3000; further preferably, the molar ratio of the intermediate 4 to the monomer AB2 is 1:(8.5m~9.0m).

[0048] As a preferred embodiment, the molar ratio of the fluorinated hyperbranched polyurethane to the siloxane in the substitution reaction II is 1:(16m~19.2m), where m=an integer from 1 to 3000; further preferably, the molar ratio of the fluorinated hyperbranched polyurethane to the siloxane is 1:(18m~18.2m).

[0049] As a preferred embodiment, the perfluoroalkyl acetate compound is perfluoroalkyl methyl acetate or perfluoroalkyl ethyl acetate; more preferably, the perfluoroalkyl acetate compound is perfluoroalkyl ethyl acetate.

[0050] As a preferred embodiment, the diisocyanate is isophorone diisocyanate, toluene diisocyanate or hexamethylene diisocyanate. Further preferably, the diisocyanate is isophorone diisocyanate. Experiments have found that the use of isophorone diisocyanate can further improve the hydrophobic antifouling, friction resistance, chemical corrosion resistance and aging resistance of the fluorinated hyperbranched polyurethane.

[0051] As a preferred embodiment, the siloxane is at least one of trimethoxysilane, dimethoxysilane, methoxysilane, triethoxysilane, diethoxysilane and ethoxysilane. Further preferably, the siloxane is trimethoxysilane. Experiments have shown that the use of trimethoxysilane for end-capping treatment helps to further improve the stability, hydrophobicity and antifouling, smoothness and other properties of the fluorinated hyperbranched polyurethane.

[0052] The present invention provides a method for preparing a fluorine-containing hyperbranched polyurethane terminated with siloxane, which specifically comprises the following steps:

[0053] 1) Weigh a perfluoroalkyl acetate compound and diethanolamine into a reactor, use 0.5 wt% NaOH solution as a catalyst, and carry out substitution reaction I at 100° C. in a nitrogen atmosphere to obtain intermediate 1;

[0054] 2) Weighing intermediate 1 and maleic anhydride, adding them into a reactor, using tetrahydrofuran as solvent, and carrying out esterification reaction at room temperature in a nitrogen atmosphere to obtain intermediate 2;

[0055] 3) Weigh the intermediate 2, diethanolamine and acetone into a reactor, and carry out amidation reaction I at 80-120°C in a nitrogen atmosphere to obtain the intermediate 3;

[0056] 4) Add diisocyanate, diethanolamine and acetone into a reactor, and carry out amidation reaction II in an ice-water bath in a nitrogen atmosphere to obtain monomer AB2;

[0057] 5) intermediate 3 and monomer AB2 are added to a reactor, and amidation reaction III is carried out at 60-80° C. in a nitrogen atmosphere using dibutyltin dilaurate as a catalyst to obtain intermediate 4; intermediate 4 is then further polymerized with monomer AB2 to obtain fluorine-containing hyperbranched polyurethane;

[0058] 6) The fluorinated hyperbranched polyurethane, siloxane and catalyst are added to a reactor, and a substitution reaction II is carried out at room temperature in a nitrogen atmosphere to finally obtain a fluorinated hyperbranched polyurethane terminated with siloxane.

[0059] Finally, the present invention also provides a photocurable coating, comprising the above-mentioned siloxane-terminated fluorine-containing hyperbranched polyurethane, and the polyurethane and other components work synergistically to give the coating good adhesion, better hydrophobicity and wear resistance.

[0060] As a preferred solution, the photocurable coating includes the following mass parts: 10 to 50 parts of fluorine-containing hyperbranched polyurethane terminated by siloxane; 1 to 5 parts of photoinitiator; 0.5 to 5 parts of leveling agent; 10 to 20 parts of solvent. The fluorine-containing hyperbranched polyurethane terminated by siloxane of the present invention can be uniformly mixed with other components due to its low viscosity, and has good film-forming properties. The active groups in the fluorine-containing hyperbranched polyurethane terminated by siloxane can be quickly activated by the action of the photoinitiator, so that the special hyperbranched structure of the fluorine-containing hyperbranched polyurethane can be used to enrich the fluorine-containing groups on the coating surface, providing a lasting hydrophobic and oleophobic performance, and the siloxy active groups and fluorine-containing active groups in the fluorine-containing hyperbranched polyurethane terminated by siloxane The coordinated hyperbranched structure can improve the stability and adhesion of the coating. In addition, in order to avoid the problems of orange peel, fish eyes, shrinkage cavities, pinholes, shrinkage edges, etc. that may occur during the curing process, an appropriate amount of leveling agent is added to make it have a suitable surface tension and the ability to reduce the surface tension gradient, further promoting the formation of a film layer with hydrophobic antifouling, friction resistance and other properties.

[0061] As a preferred solution, the photoinitiator is one of 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1-(4-methylthiophenyl)-2-morpholinyl-1-propanone, and methyl benzoylformate; the leveling agent is one of KE1203, HY1203, and BYK-3500; and the solvent is one of acetone, butanone, ether, and n-butanol.

[0062] As a preferred solution, the photocuring uses UV light with a main peak of 365nm and a power of 100-140mW to perform film curing, and the curing time is 30-90s.

[0063] Compared with the prior art, the technical solution of the present invention brings about innovative and beneficial technical effects:

[0064] 1) The fluorinated hyperbranched polyurethane terminated with siloxane provided by the present invention is constructed into a hyperbranched structure by continuous polymerization of the intermediate 3 and the AB2 monomer, and the molecules are not easily entangled. It not only has low viscosity and excellent film-forming properties, but also, due to the presence of the perfluoroalkyl group and the siloxane structure used for end-capping and the synergistic effect of the hyperbranched structure, the polymer is endowed with excellent hydrophobic antifouling, friction resistance, chemical corrosion resistance and aging resistance, and has obvious advantages when applied to membrane materials.

[0065] 2) The present invention provides a method for preparing a fluorine-containing hyperbranched polyurethane terminated with a siloxane group. The preparation method is simple and easy to operate, has a high reaction rate, and is under mild conditions, and is conducive to large-scale production.

[0066] 3) The presence of the hyperbranched structure of the present invention gives the polyurethane a large number of terminal hydroxyl structures, which require more siloxane for end-capping treatment, thereby generating abundant silicon-oxygen bonds, which play a bridging role in the polyurethane curing process, greatly enhancing the bonding force between the material and the substrate, thereby greatly improving the wear resistance of the coating and the stability of the overall structure of the polymer. At the same time, since the silicon-oxygen bonds are located at the end of the molecular chain, they are more likely to be tightly combined with the substrate, prompting the fluorine-containing groups to face the air side, achieving the enrichment of the fluorine-containing groups on the coating surface, and significantly enhancing the hydrophobic antifouling effect and weather resistance of the coating. BRIEF DESCRIPTION OF THE DRAWINGS

[0067] Figure 1 This is the FTIR spectrum of the siloxane-terminated fluorine-containing hyperbranched polyurethane prepared in Example 1.

[0068] Figure 2 This is a test diagram of the initial water drop angle on the substrate surface in Example 1. DETAILED DESCRIPTION

[0069] The technical solution of the present invention will be further described below in conjunction with specific embodiments of the present invention. It should be noted that the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments; these embodiments are only for a better understanding of the present invention, rather than limiting the scope of protection of the present invention.

[0070] Unless otherwise specified, all reagents and raw materials used in the present invention are commercially available products or products that can be prepared by known methods.

[0071] The room temperature of the present invention is 25°C.

[0072] Example 1

[0073] The fluorine-containing hyperbranched polyurethane terminated with siloxane provided in this embodiment has the structural formula as shown below:

[0074] ,

[0075] Wherein, Rf is perfluorooctyl;

[0076] R is the main structure of isophorone diisocyanate, and its structural formula is as follows:

[0077] ,

[0078] It is the main polymer structure of isophorone diisocyanate and diethanolamine, and is composed of m repeated structural units as follows:

[0079] ,

[0080] Among them, m=10.

[0081] The preparation method comprises the following steps:

[0082] 1) Weigh ethyl perfluorooctyl acetate and diethanolamine into a reactor (molar ratio of 1:1.2), use 0.5wt% NaOH solution as a catalyst, and carry out substitution reaction at 100°C in a nitrogen atmosphere to obtain intermediate 1;

[0083] 2) Weighing intermediate 1 and maleic anhydride into a reactor (molar ratio of 1:2.2), using tetrahydrofuran as solvent, and carrying out esterification reaction at room temperature in a nitrogen atmosphere to obtain intermediate 2;

[0084] 3) Weighing intermediate 2 and diethanolamine in a molar ratio of 1:2.4, adding them into a reactor, and carrying out amidation reaction I under the action of acetone in a nitrogen atmosphere at 100°C to obtain intermediate 3;

[0085] 4) Weigh isophorone diisocyanate and diethanolamine and add them into the reactor (molar ratio is 1:1.1), and carry out amidation reaction II in an ice-water bath under the action of acetone in a nitrogen atmosphere to obtain monomer AB2;

[0086] 5) Take intermediate 3 and monomer AB2 and add them into the reactor (molar ratio is 1:4.4), use dibutyltin dilaurate (dosage is 2mmol / L) as catalyst, carry out amidation reaction III at 70°C in nitrogen atmosphere to obtain intermediate 4. Then, intermediate 4 continues to carry out polymerization reaction (temperature is 70°C) with monomer AB2 (molar ratio is 1:8.6m) to obtain fluorine-containing hyperbranched polyurethane;

[0087] 6) Add fluorinated hyperbranched polyurethane and trimethoxysilane into a reactor (molar ratio of 1:18m), and carry out substitution reaction at room temperature in a nitrogen atmosphere under the action of zinc acetate catalyst (dosage of 5mmol / L), and finally obtain fluorinated hyperbranched polyurethane terminated with trimethoxysilane.

[0088] Example 2

[0089] The fluorine-containing hyperbranched polyurethane terminated with siloxane provided in this embodiment has the structural formula as shown below:

[0090] ,

[0091] Wherein, Rf is perfluorohexyl;

[0092] R is the main structure of hexamethylene diisocyanate, and its structural formula is as follows:

[0093] ,

[0094] It is the main polymer structure of hexamethylene diisocyanate and diethanolamine, and is composed of m repeated structural units as follows:

[0095] ,

[0096] Among them, m=8.

[0097] The preparation method comprises the following steps:

[0098] 1) Weigh perfluorohexyl ethyl acetate and diethanolamine into a reactor (molar ratio of 1:1.1), use 0.5wt% NaOH solution as a catalyst, and carry out substitution reaction at 100°C in a nitrogen atmosphere to obtain intermediate 1;

[0099] 2) Weighing intermediate 1 and maleic anhydride into a reactor (molar ratio of 1:2.1), using tetrahydrofuran as solvent, and carrying out esterification reaction at room temperature in a nitrogen atmosphere to obtain intermediate 2;

[0100] 3) Weighing intermediate 2 and diethanolamine in a molar ratio of 1:2.1, adding them into a reactor, and carrying out amidation reaction I under the action of acetone in a nitrogen atmosphere at 100°C to obtain intermediate 3;

[0101] 4) Hexamethylene diisocyanate and diethanolamine were weighed and added into the reactor (molar ratio was 1:1.2), and amidation reaction II was carried out in an ice-water bath in a nitrogen atmosphere under the action of acetone to obtain monomer AB2;

[0102] 5) Take intermediate 3 and monomer AB2 and add them into the reactor (molar ratio is 1:4.5), use dibutyltin dilaurate as catalyst (dosage is 2mmol / L), carry out amidation reaction III at 65°C in nitrogen atmosphere to obtain intermediate 4. Then, intermediate 4 continues to carry out polymerization reaction (temperature is 65°C) with monomer AB2 (molar ratio is 1:8.2m) to obtain fluorine-containing hyperbranched polyurethane;

[0103] 6) Add fluorinated hyperbranched polyurethane and triethoxysilane into a reactor (molar ratio of 1:17.6m), and carry out substitution reaction at room temperature in a nitrogen atmosphere under the action of zinc acetate catalyst (dosage of 5mmol / L), and finally obtain triethoxysilane-terminated fluorinated hyperbranched polyurethane.

[0104] Example 3

[0105] The fluorine-containing hyperbranched polyurethane terminated with siloxane provided in this embodiment has the structural formula as shown below:

[0106] ,

[0107] Wherein, Rf is perfluorooctyl;

[0108] R is the main structure of toluene diisocyanate, and its structural formula is as follows:

[0109] ;

[0110] It is the main polymer structure of toluene diisocyanate and diethanolamine, and its structural formula is:

[0111] ,

[0112] Among them, m=13.

[0113] The preparation method comprises the following steps:

[0114] 1) Weigh ethyl perfluorooctyl acetate and diethanolamine into a reactor (molar ratio of 1:1.2), use 0.5wt% NaOH solution as a catalyst, and carry out substitution reaction at 100°C in a nitrogen atmosphere to obtain intermediate 1;

[0115] 2) Weighing intermediate 1 and maleic anhydride into a reactor (molar ratio of 1:2.4), using tetrahydrofuran as solvent, and carrying out esterification reaction at room temperature in a nitrogen atmosphere to obtain intermediate 2;

[0116] 3) Weighing intermediate 2 and diethanolamine in a molar ratio of 1:2.2, adding them into a reactor, and carrying out amidation reaction I under the action of acetone in a nitrogen atmosphere at 100°C to obtain intermediate 3;

[0117] 4) Weigh toluene diisocyanate and diethanolamine and add them into the reactor (molar ratio is 1:1.2), and carry out amidation reaction II in an ice-water bath in a nitrogen atmosphere under the action of acetone to obtain monomer AB2;

[0118] 5) Take intermediate 3 and monomer AB2 and add them into the reactor (molar ratio is 1:4.6), use dibutyltin dilaurate as catalyst (dosage is 2mmol / L), carry out amidation reaction III at 70°C in nitrogen atmosphere to obtain intermediate 4. Then, intermediate 4 continues to carry out polymerization reaction (temperature is 70°C) with monomer AB2 (molar ratio is 1:9.3m) to obtain fluorine-containing hyperbranched polyurethane;

[0119] 6) Fluorinated hyperbranched polyurethane and dimethoxysilane were added into a reactor (molar ratio of 1:18.5m), and a substitution reaction was carried out in a nitrogen atmosphere at room temperature under the action of zinc acetate catalyst (dosage of 5mmol / L), and finally a fluorinated hyperbranched polyurethane terminated with dimethoxysilane was obtained.

[0120] Comparative Example 1

[0121] Compared with Example 1, the difference in this comparative example is that ethyl perfluorooctyl acetate is replaced by ethyl decanoate, and the other preparation steps and conditions are the same.

[0122] Comparative Example 2

[0123] Compared with Example 1, this comparative example differs in that no trimethoxysilane is added, and the other preparation steps and conditions are the same.

[0124] Comparative Example 3

[0125] The difference between this comparative example and Example 1 is that the chain extension of AB2 monomer is not performed, but trimethoxysilane is directly used for end-capping (that is, trimethoxysilane is used for end-capping after obtaining intermediate 4), and the other preparation steps are the same.

[0126] The hyperbranched polyurethane prepared in Examples 1, 2, 3 and Comparative Examples 1, 2, 3 was uniformly mixed with a photoinitiator 1-hydroxycyclohexyl phenyl ketone, a leveling agent HY1203, and a solvent n-butanol (in a weight ratio of 20 parts: 1.2 parts: 0.5 parts: 12 parts), and then evenly and precisely applied to the surface of the substrate, and cured into a film by UV irradiation (main peak of 365 nm, power of 120 mW, curing time of 40 s).

[0127] Comparative Example 4

[0128] The difference between this comparative example and Example 1 is that no leveling agent HY1203 is added during UV curing, and the other preparation steps are the same.

[0129] By testing the light transmittance, initial water drop angle, rubber friction resistance, steel wool friction resistance, chemical water corrosion resistance, dynamic friction coefficient and other properties of the substrate surface, the test results are shown in Table 1 below.

[0130] Light transmittance test method: Light transmittance is measured by TH-110 light transmittance haze meter. Place the coated substrate on the test platform, press the HOLD key of the instrument, and start the test after the instrument passes the self-calibration, and record the test results.

[0131] Hydrophobic angle test method: The static contact angle of the coating is measured by a JGW-360a contact angle meter. The test liquid volume is 2μL, the test environment is 24±1℃, and the relative humidity is 45±1%. The water droplet touch angle is measured at 5 points and the average value is taken.

[0132] Rubber abrasion resistance test method: The rubber abrasion resistance test is measured by ZJ-339-GSR wear tester. The coated substrate is fixed on the tester, the pressure is set to 1000g, the stroke is set to 40mm, and the speed is 40cycles / min. After the test, the substrate water drop angle test results are recorded.

[0133] Steel wool abrasion resistance test method: The steel wool abrasion resistance test is measured by ZJ-339-GSR wear tester. The coated substrate is fixed on the tester. The rubber model is MUNBANGSAWOO, the pressure is set to 1000g, the stroke is set to 40mm, and the speed is 40cycles / min. After the test, the water drop angle test results of the substrate are recorded.

[0134] Chemical water resistance test method: The chemical water resistance test is measured by ZJ-339-GSR wear tester. The coated substrate is fixed on the tester. The chemical solution is anhydrous ethanol, the pressure is set to 1000g, the stroke is set to 40mm, and the speed is 40cycles / min. After the test, the substrate water drop angle test results are recorded.

[0135] Dynamic friction coefficient test method: The dynamic friction coefficient of the substrate surface was measured using an MXD-02 friction coefficient tester with a load of 200g.

[0136]

[0137] As shown in Table 1, it can be seen from the data of Examples 1 to 3 that the fluorine-containing hyperbranched polyurethane terminated by siloxane has advantages such as good hydrophobicity, high transmittance and good wear resistance after being attached to the substrate surface as a film material, and its initial water drop angle is all>115°. Among them, the fluorine-containing hyperbranched polyurethane terminated by siloxane prepared by Example 1 has more excellent comprehensive performance. While in Comparative Example 1 and Comparative Example 2, due to the fact that perfluoroalkyl and end-capped trimethoxysilane are not added respectively, the hydrophobicity of the substrate surface obtained does not show significant differences in transmittance and dynamic friction coefficient, but shows obvious reduction in hydrophobicity, friction resistance and corrosion resistance. In addition, it can be found from the result of Comparative Example 3 that due to the lack of hyperbranched structure, the hydrophobicity, friction resistance, chemical water corrosion resistance and smoothness of the substrate surface are all significantly reduced, which shows that the present invention is a good effect obtained by simultaneously utilizing the hyperbranched structure in the fluorine-containing hyperbranched polyurethane terminated by siloxane and the introduced modifying group. The results of Comparative Example 4 show that a suitable leveling agent helps the film layer formed by the siloxane-terminated fluorinated hyperbranched polyurethane adopted in the present invention to have hydrophobic, anti-fouling and friction-resistant properties, and can also effectively alleviate problems such as decreased smoothness and blurred vision caused by defects such as orange peel, fish eyes, shrinkage cavities, pinholes, and edge shrinkage.

[0138] The fluorine-containing hyperbranched polyurethane terminated with siloxane prepared in Example 1 was tested by FTIR, and the results are as follows: Figure 1 As shown. It can be found that at 3380cm -1 and 1530cm -1 The absorption bands at 2954cm and 2964cm come from the stretching vibration and bending vibration of amine nitrogen. -1 and 2870cm -1 , 1460cm -1 and 1383cm -1 Typical tensile and bending vibrations are shown at 1742cm -1 The absorption peak at 1139cm is caused by the stretching vibration of C=O. -1 and 1054cm -1 The absorption peaks at 1227cm are the stretching vibration and bending vibration of COC. -1 The broad absorption peak at 735 cm -1 and 704cm -1 The signal at 846 cm is attributed to the carbon-fluorine bond. -1The absorption peak at is attributed to the Si-OC bond. Figure 2 This is a test diagram of the initial water drop angle after Example 1 is applied to the substrate surface.

[0139] The above embodiments are only for better explanation of the principles and practical applications of the present invention, so that those skilled in the relevant technical field can better understand and utilize the present invention, but they are not intended to limit the patent scope of the present invention. All equivalent changes made using the contents of the present invention are within the patent protection scope of the present invention.

Claims

1. A fluorine-containing hyperbranched polyurethane terminated with siloxane, characterized in that: Having a structure such as formula I: Wherein, Rf is a perfluoroalkyl group having a structure as shown in Formula II: CF3(CF2) n -* Formula II; n is an integer from 1 to 20; R1 is It is composed of m repeated structures of formula III; Wherein, m is an integer from 1 to 3000, R1 is R2 is or *-O-SiH2-OEt; * indicates bonding site.

2. The method for preparing a fluorine-containing hyperbranched polyurethane terminated with siloxane according to claim 1, characterized in that: A perfluoroalkyl acetate compound and diethanolamine are subjected to a substitution reaction I to obtain an intermediate 1; the intermediate 1 is subjected to an esterification reaction with maleic anhydride to obtain an intermediate 2; the intermediate 2 is further subjected to an amidation reaction I with diethanolamine to obtain an intermediate 3; The intermediate 3 and the monomer AB2 are subjected to an amidation reaction III under the catalysis of dibutyltin dilaurate to obtain an intermediate 4; the intermediate 4 is further subjected to a polymerization reaction with the monomer AB2 to obtain a fluorine-containing hyperbranched polyurethane; the fluorine-containing hyperbranched polyurethane is subjected to a substitution reaction II with siloxane to obtain; The monomer AB2 is obtained by amidation reaction II of diisocyanate and diethanolamine; Among them, intermediate 1 has a structure as shown in Formula IV: Intermediate 2 has a structure of Formula V: Intermediate 3 has the structure of Formula VI: Intermediate 4 has the structure of Formula VII: The fluorinated hyperbranched polyurethane has a structure such as Formula VIII: Monomer AB2 has the structure of Formula IX:

3. The method for preparing a fluorine-containing hyperbranched polyurethane terminated with siloxane according to claim 2, characterized in that: The molar ratio of the perfluoroalkyl acetate compound to diethanolamine in the substitution reaction I is 1:(1-1.2).

4. The method for preparing a fluorine-containing hyperbranched polyurethane terminated with siloxane according to claim 2 or 3, characterized in that: The molar ratio of the intermediate 1 to maleic anhydride in the esterification reaction is 1:(2-2.4).

5. The method for preparing a fluorine-containing hyperbranched polyurethane terminated with siloxane according to claim 4, characterized in that: The molar ratio of the intermediate 2 to diethanolamine in the amidation reaction I is 1:(2-2.4); the molar ratio of the diisocyanate to diethanolamine in the amidation reaction II is 1:(1-1.2); the molar ratio of the intermediate 3 to the monomer AB2 in the amidation reaction III is 1:(4-4.8).

6. The method for preparing a siloxane-terminated fluorine-containing hyperbranched polyurethane according to claim 5, characterized in that: The molar ratio of the intermediate 4 to the monomer AB2 in the polymerization reaction is 1:(8m-9.6m), wherein m is an integer of 1-3000.

7. The method for preparing a siloxane-terminated fluorine-containing hyperbranched polyurethane according to claim 6, characterized in that: The molar ratio of the fluorine-containing hyperbranched polyurethane to the siloxane in the substitution reaction II is 1:(16m-19.2m), wherein m is an integer of 1-3000.

8. The method for preparing a siloxane-terminated fluorine-containing hyperbranched polyurethane according to claim 7, characterized in that: The perfluoroalkyl acetate compound is perfluoroalkyl methyl acetate or perfluoroalkyl ethyl acetate; The diisocyanate is isophorone diisocyanate, toluene diisocyanate or hexamethylene diisocyanate; The siloxane is at least one of trimethoxysilane, dimethoxysilane, methoxysilane, triethoxysilane, diethoxysilane and ethoxysilane.

9. A light-curing coating, characterized in that: The invention comprises the fluorine-containing hyperbranched polyurethane terminated with siloxane as claimed in claim 1.

10. A photocurable coating according to claim 9, comprising the following components by weight: 10 to 50 parts of fluorine-containing hyperbranched polyurethane terminated with siloxane; 1 to 5 parts of photoinitiator; 0.5 to 5 parts of leveling agent; and 10 to 20 parts of solvent.

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